Colorado River Basin 

Salinity Control Project 

Paradox Valley Unit 

Final Supplemental 

Definite Plan Report and 

Environmental Assessment 

Mayl997 

United States 

Department of the Interior 

Bureau of Reclamation 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Distribution List 

Honorable Hank Brown 

U.S. Senate, Washington, D.C. 

Honorable Ben Nighthorse Campbell 

U.S. Senate, Washington, D.C. 

Honorable Scott Mcinnis 

U. S. House of Representatives, 

Washington, D.C. 

Bureau of Land Management 

Montrose, and Durango, Colorado 

Corps of Engineers, Grand Junction, 

Colorado 

Environmental Protection Agency, 

Denver, Colorado 

U.S. Fish and Wildlife Service, Grand 

Junction, Colorado and Salt Lake City, 

Utah 

U.S. Geological Survey, Denver, Colorado 

U.S. Forest Service, Lakewood, Colorado 

Cyprus Foote Mineral, Exton, 

Pennsylvania 

Colorado Division of Wildlife, Montrose, 

Colorado 

Colorado Water Conservation Board, 

Denver, Colorado 

Colorado River Basin Salinity Forum, 

Bountiful, Utah 

Montrose Community Economic 

Development, Montrose, Colorado 

Naturita Town Clerk, Naturita, Colorado 

Norwood Town Clerk, Norwood, Colorado 

Nucla Town Clerk, Nucla, Colorado 

San Miguel Water Conservancy District, 

Norwood, Colorado 

San Miguel Power Association, 

Nucla, Colorado 

Union Carbide Corporation, 

Grand Junction, Colorado 

Upper Colorado River Commission, 

Salt Lake City, Utah 

Utah Department of Environmental 

Quality, Salt Lake City, Utah 

Western Area Power Administration, 

Salt Lake City, Utah 

National Audubon Society, Boulder, 

Colorado 

Sierra Club, Denver, Colorado 

Wilderness Society, Denver, Colorado 

Cortez Public Library, Cortez, Colorado 

Dolores Public Library, Dolores, Colorado 

Durango Public Library, Durango, 

Colorado 

Grand County Library, Moab, Utah 

Mesa County Public Library, Grand 

Junction, Colorado 

Montrose District Library, Montrose, 

Colorado 

Montrose Regional Library, Naturita, 

Colorado 

Norwood Public Library, Norwood, 

Colorado 

Nucla Public Library, Nucla, Colorado 

Nucla High School, Nucla, Colorado 

Loyd A. Carlson, Grand Junction, 

Colorado 

Mark J. Hovezak, Durango, Colorado 

Ruth Hutchins Family, Fruita, Colorado 

Mort Jensen, Bedrock, Colorado 

Carol Sue Latham, Bedrock, Colorado 

Glen A. Miller, Grand Junction, Colorado 

Clint Oliver, Paradox, Colorado 

Paul Redd, Redd Ranches, Paradox, 

Colorado 

Jerry Swingle, Durango, Colorado 

UCR07240 

Colorado River Basin Salinity Control Project 

PARADOX VALLEY UNIT 

Final Supplemental Definite Plan Report 

Chapter 1-Introduction 

Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Contents 

Page 

Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I -I 

Need for Action .............................................................. I-2 

Authority ................................................................... I -4 

Relationships to Other Activities ................................................ I -4 

Public Involvement ........................................................... I-4 

Chapter IT-Unit Setting 

Location ................................................................... II-I 

Geology, Seismicity, and Tectonics ............................................. II-I 

Water Resources ............................................................ II-5 

Streams ................................................................ II-5 

Groundwater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . II-7 

Climate ................................................................... II-7 

Vegetation ................................................................. II-7 

Flood Plain and Wetland ...................................................... II-8 

Wildlife ................................................................... II-8 

Fish ...................................................................... II-8 

Endangered Species ......................................................... II-8 

Cultural Resources .......................................................... II-8 

Chapter III-Paradox Valley Hydrology 

Water Resources ........................................................... III-I 

Surface Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . III -I 

Ground Water .......................................................... III-3 

Water Quality ............................................................. III-3 

Surface Water .......................................................... III-3 

Ground Water .......................................................... III-4 

Potential for Scale Formation ................................................. III-6 

Chapter IV-Unit Development 

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IV -I 

Project Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IV -I 

Brine Well Field . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IV -I 

Production Wells .................................................... IV-I 

Monitoring Wells .................................................... IV-2 

Surface Treatment Facility ................................................ IV-3 

Brine Transfer Pipeline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IV-3 

Brine Injection Components ............................................... IV-3 

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Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Contents 

Page 

Brine Injection Facility ............................................... IV-3 

Water Treatment Plant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IV -4 

Well Annulus Monitoring System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IV -4 

Injection Well ...................................................... IV-4 

Electrical Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IV -5 

Access Road and Office Facility ........................................ IV-5 

Seismic Monitoring Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IV -5 

Dolores River Monitoring System .......................................... IV-6 

Protection of Unit Works from Flood Hazards .................................... IV-7 

Water Rights, Permits, and Augmentation Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IV-7 

Mineral Rights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IV-7 

Rights-of-Way . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IV-7 

CulturalResources Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IV -8 

Wildlife Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IV -8 

Operation and Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IV -8 

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IV -8 

Power ................................................................ IV-8 

Unit Costs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IV -9 

Construction Costs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IV -9 

Annual Operation, Maintenance, and Replacement Costs . . . . . . . . . . . . . . . . . . . . . . . IV -l 0 

Financial and Economic Analyses . . . . . . . . .. . .. .. . . . . . . . . . .. . . . . .. .. . . . . . . . .. . IV -l 0 

Benefits .............................................................. IV-10 

Cost Per Ton of Salt Removed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IV -I 0 

Cost Allocation and Repayment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IV -II 

Chapter V-Alternatives 

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V-I 

Proposed Action-Continue Operation of Test Injection Well ........................ V-1 

No Action Alternative ........................................................ V -1 

Chapter VI-Appendices 

Appendix A - Environmental Assessment for Supplemental Definite Plan Report 

Appendix B - Biological Assessment 

Appendix C - Biological Opinion 

Appendix D - Comments and Responses 

Tables 

Table Page 

I-1 Numeric criteria for the Lower Colorado River .................................. I-3 

III-I Average runoff in the Paradox Valley ....................................... III-I 

III-2 Reclamation lab data averages per well; 1983-86 .............................. Ill-S 

III-3 Chemical composition of formation water .................................... Ill-7 

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Supplemental Definite Plan Report/Environmental Assessment 

IV -I Deep well injection (proposed action) estimated costs . . . . . . . . . . . . . . . . . . . . . . . . . . IV -9 

IV-2 Cost allocation and repayment summary deep well injection 

(proposed action) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IV -II 

V-I Second injection well alternative estimated costs ............................... V -3 

V-2 Radium Evaporation Pond Alternative estimated costs ........................... V-6 

V-3 Power requirements for Paradox Valley Unit ................................. V-10 

Figures 

Figure Page 

I-1 General Map, Paradox Valley Unit ............................. follows Introduction 

II-I Paradox Anticline, Stages of Development .................................... II-3 

II-2 Stratigraphic Chart of Paradox Valley Unit .................................... II-4 

II-3 Confining Rock Formations Above Leadville Injection .......................... II-6 

II-4 Location Map for Brine Well Field and Brine Injection Site ...................... Ill-8 

iii 

Purpose 

Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Chapter I 

Introduction 

The Paradox Valley Unit (Unit) of the Colorado River Basin Salinity Control Project (CRBSCP) is 

located in Montrose County in southwestern Colorado and is designed to control natural brine 

inflows into the Dolores River. The Paradox Valley has long been identified as a major contributor 

of salt loading in the Colorado River Basin. The Valley overlies a fractured gypsum cap that covers 

a formation of salt and salt-rich shale that begins at a depth of about 600 to l ,000 feet and extends 

downward for about 14,000 feet. The Dolores River picks up an estimated 205,000 tons of salt 

annually as it crosses the valley, primarily from the surfacing of natural brine groundwater. The 

purpose of the Unit is to intercept the brine and prevent this substantial salt load from entering the 

river and degrading the water quality of the main stem of the Colorado River. 

The Bureau of Reclamation (Reclamation) began studies at Paradox Valley in 1971. By 1979, a 

Definite Plan Report and Final Environmental Statement had been approved recommending a plan 

that would prevent approximately 90 percent of the natural brine inflow (185,000 tons of salt 

annually) from entering the Dolores River. The recommended plan consisted of constructing a series 

of shallow brine production wells adjacent to the river, pumping the wells at a collective rate of 5 

cubic feet per second ( cfs) to intercept the brine, transporting the brine via a 21-mile-long pipeline 

and eight pumping stations to Dry Creek Basin, and disposing of the brine by evaporation in the 

3,630-acre Radium Evaporation Pond. Deep well injection was one of the alternative brine disposal 

methods discussed briefly in the environmental statement but was eliminated because the proposed 5 

cfs disposal rate was estimated to be higher than the geologic formations could absorb. The Region 

VIII Office of the Environmental Protection Agency reviewed the 1978 Draft Environmental 

Statement and stated that it "believes that disposal by deep well injection is the environmentally 

preferred solution and therefore should be seriously investigated for brine disposal" (BOR, 1978). 

Subsequent investigations and testing of the brine well field indicated the desired reduction of 90% 

of brine flow into the river could be met by intercepting and disposing of approximately 2 cfs of 

brine. Based on this new information, in September 1978, Reclamation initiated an action to conduct 

a study to investigate the feasibility of brine disposal by injection. Two separate studies were 

conducted by consulting engineering firms and, in August 1985, the final design for a deep-well 

injection testing program was completed. 

Construction of Test Injection Well No.1 began in July 1986 at a site located approximately 1.2 

miles south of Bedrock, Colorado, in the Dolores River Canyon. A welll6,000 feet deep was drilled 

into the underlying Mississippian and Precambrian rock formations. Preliminary tests indicated 

these formations would be favorable injection zones. Construction of a surface injection facility, 

brine treatment facility, and pipelines connecting these facilities with the brine well field proceeded 

concurrently with the injection well construction. All facilities were completed by January 1990. 

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Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Initial shakedown testing of the new facility equipment revealed several deficiencies in the 

mechanical and electrical equipment associated with pressurizing the brine up to 5,000 pounds per 

square inch injection pressure. These deficiencies were corrected, and in July 1991, injection testing 

was initiated to provide information concerning the necessary injection pressure and expected life of 

the well. Additional mechanical and electrical problems with the surface equipment were 

encountered which resulted in the injection test proceeding on an intermittent basis as the surface 

facilities and equipment were upgraded to sufficient production levels. By July 1994 the major 

equipment problems were resolves and an 8-month continuous injection sequence began. Results of 

the injection testing indicate that deep-well injection of the brine is a feasible method of brine 

disposal in the Paradox Valley. 

This Supplement to the Definite Plan Report (SDPR) for the Paradox Valley Unit, Colorado, 

Colorado River Basin Salinity Control Project (CRBSCP), describes modifications to the project 

plan of development that have occurred since the original DPR was completed. The attached 

Environmental Assessment (EA) evaluates the environmental effects of operating the presently 

constructed deep-well injection facility as the Unit's contribution to the Colorado River Basin 

salinity control effort. 

Need for Action 

In the Colorado River Basin, salinity in rivers results from two general causes--salt loading and salt 

concentration. Salt loading is the addition of salt to the river from such sources as the dissolving of 

salt from saline geologic formations, as occurs in the Paradox Valley. Other sources include 

irrigation return flows and saline springs. Under present conditions, the annual salt load of the river 

into Lake Mead in the Lower Colorado River Basin is estimated at 9 million tons. Salt concentration 

results from consumptive use of water without reducing the total salt carried. Some examples 

include irrigation, municipal and industrial (M&I) use, transpiration by native vegetation, and 

evaporation. 

When water is used and reused along the entire length of the Colorado River, salt loading and salt 

concentration contribute to increased levels of salinity and a deterioration of the quality of the river's 

water. At its headwaters in the mountains of north-central Colorado, the Colorado River has a 

salinity concentration of approximately 50 milligrams per liter (mg/L). Downstream, the 

concentration progressively increases. At Imperial Dam, the last major diversion point in the United 

States, the salinity in 1995 averaged 787 mg/L. Historical salinity concentrations fluctuate annually 

with the total basin water supply but, as the Upper Colorado River Basin States continue to use and 

develop their water, salinity will increase. It is estimated that by the year 2015, salinity at Imperial 

Dam will aYerage 970 mg/L without controls. 

Water of 1,000 mg/L or less is generally considered to be satisfactory for irrigating most crops, 

although concentrations of 500 mg/L can have detrimental effects on salt-sensitive crops. Water 

exceeding LOOO mg/L may be used only on land with good drainage and for crops with high salt 

tolerances. According to the EPA's secondary drinking water standards, public drinking water 

should be less than 500 mg/L. 

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Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

In the Lower Colorado River Basin, high salinity levels adversely affect more than 18 million people 

and about 2 million acres of irrigated farmland. Those most affected are the M&I water users in the 

Los Angeles-San Diego area, and irrigators in Arizona and southern California, especially in the 

Imperial Valley. 

The estimated damages from salinity exceed $750 million per year1 The losses from M&I use occur 

mainly from increased water treatment costs, pipe corrosion, appliance wear, increased soap and 

detergent needs, automobile radiator deterioration, and decreased drinking water palatability. For 

irrigators, the higher salt concentrators cause decreased crop yields, loss of productive land, forced 

changes to more salt-tolerant crops, increased leaching and drainage needs, and increased 

management costs. 

To limit the salinity of the Colorado River and in response to the Federal Water Pollution Control 

Act and its 1972 amendments, Public Law 92-500, the seven Colorado River Basin States, acting 

through the Colorado River Basin Salinity Control Forum, developed numeric criteria and a basin 

wide plan of implementation for salinity control. In 1975, the states adopted these water quality 

standards for salinity. The numeric criteria are shown in table I-I. 

Table 1-1.-Numeric criteria for the 

Lower Colorado River 

Station 

Below Hoover Dam 

Below Parker Dam 

At Imperial Dam 

Annual flow-weighted 

concentration 

(mg/L) 

723 

747 

879 

The goal of the CRBSCP is to maintain average concentrations at or below these criteria. About 1.4 

million tons of salt per year needs to be removed by 20 I 0 to maintain average salinity below the 

numeric criteria level of 879 mg/L at Imperial Dam. Even at this level of salinity reduction, 

temporary but significant amounts beyond 879 mg/L will still occur because of the natural variations 

in climatic conditions and water usage. 

Authority 

The Paradox Valley Unit was authorized for construction by the Colorado River Basin Salinity 

Control Act of 1974 (Public Law 93-320; amended in 1984 as Public Law 98-569) as part of a basin 

1 A comprehensive study to update the economic impacts of salinity in the Colorado River was published in February 1988 

(Estimating Economic Impacts of Salinity of the Colorado River, Final Report, prepared for Reclamation). This study provided 

new estimates of salinity damages as a range of costs depending upon the assumptions based on current salinity levels and 

baseline total dissolved solids (TDS) conditions used in the analysis. 

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Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

wide program to control salinity levels in the Colorado River while the Colorado River Basin States 

and the Republic of Mexico continue to develop and use their apportioned shares of water from the 

river and its tributaries. Title I of the Act, which was directed toward controlling the salinity of river 

water below Imperial Dam for use in the Republic of Mexico, authorized the construction of a 

desalting complex and other measures to ensure acceptable salinity levels. Title II, which was 

directed toward salinity control in the United States above Imperial Dam, authorized the construction 

of the Paradox Valley Unit and three other units. Preliminary information and cumulative impacts 

for the 16 original units in Title II have been presented in a FES of the Colorado River Water Quality 

Improvement Program (FES 77-15), prepared by Reclamation and the Soil Conservation Service of 

the Department of Agriculture (USDA). 

Relationships to Other Activities 

The Unit is related to Federal projects currently under investigation or construction elsewhere by 

USDA, which does not currently have any studies in the Unit area. Title II of Public Laws 93-320 

and 98-569 authorizes the Secretaries of the Interior and Agriculture to cooperate in implementing 

any project involving control of salinity from irrigation sources. To establish a program for effective 

implementation of specific cooperative activities called for by Title II, Interior and the USDA 

entered into a Memorandum of Understanding effective November 1974 and renewed on August 25, 

1986. Reclamation and the Natural Resource Conservation Service entered into a Memorandum of 

Agreement effective March 1975 and renewed on August 18, 1986. 

Public Involvement 

Throughout the study phase for the Unit modifications, the general public and interested and affected 

agencies, groups, and individuals had the opportunity to participate in the study. Reclamation 

considered information from and the opinions and desires of the public in evaluating project 

development and the salinity problem. Reclamation coordinated with and received assistance from 

the U.S. Fish and Wildlife Service (Service), the Colorado Division of Wildlife (CDOW), and the 

Bureau of Land Management (BLM). 

On November 13, 1981, a public meeting was held at the Paradox Grade School, Paradox, Colorado. 

to explain the concept of deep well injection as a method of brine disposal. The meeting was 

conducted by Reclamation and William Brothers Engineering Company, the consulting company 

that conducted the feasibility study and preliminary designs for deep well injection. TI1e day after 

this meeting, a tour of the brine well field test facilities was conducted. 

After the project proceeded to the design phase, an informal presentation was made on June 9, 1982, 

to the Ute Trail Study Club in Redvale, Colorado. In June 1984, a newsletter with an update on the 

Unit was mailed to city and county governments, newspapers, and radio and television stations 

serving the area, as well as to residents in the affected area. 

A Draft EA on the Deep Well Injection Testing Program was prepared in 1986 and was distributed to 

Federal and State agencies, public and private organizations, and interested individuals for review 

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Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

and comment. Results of that review are reflected in this draft SDPR/EA. 

Before construction of Unit facilities began, a public meeting was conducted in Naturita, Colorado, 

by Reclamation and Fenix and Scisson Inc., contractor for the injection well. 

Since 1981, news articles on the Unit have appeared in Colorado in The Denver Post; The Durango 

Herald; The San Miquel Basin Forum, Nucla; The Cortez Sentinel and Montezuma Valley Journal, 

Cortez; Montrose Daily Press, Montrose; Dolores Star, Dolores; Grand Junction Daily Sentinel; and 

in The Times Independent, Moab, Utah. 

Contact with local landowners and residents is continuing. 

I-5 
Location 

Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Chapter II 

Unit Setting 

The Paradox Valley Unit (Unit) is located in Montrose County in southwest Colorado just east of the 

Colorado-Utah State line near the Dolores River. The valley itself is about 24 miles long and 3 to 5 

miles wide. 

The only communities in Paradox Valley are the farming towns of Paradox (population 150) and 

Bedrock (population 90). Other nearby communities are Nucla (population 880), Uravan (population 

650), and Naturita (population 760), all located on or near the San Miguel River east of the valley. 

The nearest commercial centers are Moab, Utah, 60 miles northwest of Bedrock; Montrose, 

Colorado, 70 miles northeast; Grand Junction, Colorado, I 00 miles north; and Cortez, Colorado, I 00 

miles south of Bedrock. 

Although relatively isolated, the area is served by a network of Federal and State highways and 

county and local roads. Colorado State Highway 90, Utah State Highway 46, U.S. Highways 163 

and 6, and Interstates 15 and 70 provide access to Moab and Salt Lake City, Utah, about 300 miles 

northeast. Colorado State Highways 90 and 141, U.S. Highways 6 and 50, and Interstate 70 provide 

access to Montrose, Grand Junction, and Denver, Colorado (about 260 miles east of Grand Junction). 

The nearest commercial rail service is located in Grand Junction and Montrose. Commercial air and 

bus service is available in Grand Junction, Montrose, Cortez, and Moab. 

Agriculture is the main economic activity of the area. About 2,500 acres are under irrigation in the 

western half of Paradox Valley, where water supply is provided by local wells, West Paradox Creek, 

and Buckeye Reservoir in the La Sal Mountains to the northwest. Livestock and feeding livestock 

provide the principal source of income, although some barley is grown as a cash crop. The eastern 

half of the valley provides a limited amount of range in the winter and spring. 

Mining also contributes to the local economy, but has recently declined considerably. Carnotite, a 

mineral containing vanadium and the radioactive elements uranium and radium, is mined on the 

mesas surrounding Paradox Valley. Most of the ore is shipped to a processing plant in Blanding, 

Utah. Brine from a private well is sold for use in local drilling operations. 

Geology, Seismicity, and Tectonics 

Paradox Valley lies on a northwest-southeast axis and has a relatively flat floor enclosed by steep 

walls of sandstone and shale. The Dolores River crosses the valley near its midpoint in a level and 

broad flood plain but flows through deep and narrow canyons both upstream and downstream from 

the valley. Elevations vary from about 5000 feet in the valley to about 6700 feet along the valley 

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Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

rim. The most prominent nearby features are the La Sal Mountains in the Manti-La Sal National 

Forest, which rise to an elevation of about 12,000 feet and border Paradox Valley on the northwest. 

The Dolores River picks up about 200,000 tons of salt annually, primarily for surfacing brine, in 

Paradox Valley, which lies along one of five major salt anticlines identified in southwestern 

Colorado and southeastern Utah. The valley was formed by the erosion of faulted and uplifted 

sandstone and shale formations, exposing a residual gypsum cap that covers approximately 14,000 

feet of salt and salt-rich shale (Carter, 1970). Figure Il-l illustrates the development of the valley, 

which may have begun as long ago as 250 million years. The emergence of distant mountains on 

each side of the area placed lateral pressures on the intervening sedimentary formations, resulting in 

warping and fracturing along weak zones. Consequently, a deeply buried layer of salt began to flow 

upward into the fractured area, creating an elongated swell known as an anticline. The crest of the 

anticline has gradually collapsed as a result of the fracturing, and the Dolores River, combined with 

East and West Paradox Creeks and other erosional forces, has given the valley its present form. 

The Dolores River has deposited considerable amounts of alluvium in the flood plain to replace 

soluble salts that groundwater has carried into the stream from the underlying salt formation. 

Measured at a depth of up to 129 feet in places, this material consists of silty sands on the surface 

and poorly graded sands with clay-filled gravels and cobbles appearing at increasing depths. 

Discontinuous clay lenses occur randomly throughout the deposits. 

The deep well injection site, south of the Paradox salt anticline, is located so that the well bore 

penetrates all of the sedimentary rock formations and ends in the "basement" Precambrian rock. 

Figure JI-2 shows the stratigraphic relationship of the rock units drilled through during injection well 

construction. The upper 14,068 feet of the bore, composed of all the Pennsylvanian, Permian, and 

Triassic Period formations, has been cased and grouted, isolating these from injected brine. The 

remaining 1,789 feet ofthe bore is the injection zone, with Mississippian-age Leadville limestone 

serving as the primary injection formation and lower Devonian- and Cambrian-age formations 

serving as secondary injection zones. 

The geologic effects of deep-well injection of brine into the Mississippian-. Devonian-, and 

Cambrian-age formations underlying Paradox Valley are considered minimal. Based on the results 

of technical studies by Ken E. Davis Associates, Houston, Texas, Reclamation concludes that the 

Leadville, Ouray, and Elbert Formations have the desired characteristics for satisfactory long-term 

disposal of brine. These formations, 14,050 to 16,000 feet deep, are expected to have sufficient 

permeability and porosity to accept the injected brine under fracture pressure at the proposed flow 

rate. The in-situ formation water in this injection zone is already brine, and the injection of salt 

water from the brine well field would not affect a potentially usable source of potable water. 

Injected brine would be expected to remain in the designated disposal formations, with no movement 

to the surface or to freshwater zones. Drilling for the injection well encountered 234 net feet of salt 

and 92 net feet of anhydrite in the Paradox formation overlying the injection zones. The 326 net feet 

of plastic evaporite section exceeds Environmental Protection Agency (EPA) requirements for an 

impermeable barrier necessary for an injection well to operate at fracture propagation pressure. 

II-2 
. . Paradox Valley Unit 

Supplemental Deftmte Plan Report/Environmental Assessment 

·Late~ 

Pressures 

,·.·.· , ..... ;:., .... _, .... ~' 

EARLY STAG£ 

PRESENT STAG£ 

PARADOX ANTICLINE 

STAGES OF DEVELOPMENT 

Salinity Control Project 

Valley Unit 

Colorado River Basin 

Paradox 

Figure II-1. 

II-3 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

TRIASSIC MOENKOPI 

PERMIAN CUTLER 

HONAKER 3'7't0 

TRAIL 

PENN. 

MISS. 

DEVONIAN 

CAMBRIAN 

STRATIGRAPHIC CHART OF PARADOX VALLEY UNIT 

F:i.g-u.:re .I:Z::-2 

II-4 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

In addition to this barrier, the gross interval of 12,400 feet of Permo-Pennsylvanian shale, tight 

limestones and tight shaley, arkosic sandstones form another impermeable layer above the plastic 

evaporite barrier, creating a very effective barrier over the Leadville and deeper injection zones. 

Figure II-3 depicts the lateral extent of the confining salt or plastic evaporite layers and other 

confining rock formations above the Leadville injection zone. Operation of the Paradox Valley Unit 

would cause the injection formations to become abnormally highly pressurized in the immediate 

vicinity of the injection well. If future deep exploration occurs, the Bureau of Land Management 

(BLM) and/or the Colorado Oil and Gas Commission would specify in the lease that these 

pressurized conditions exist in particular locations in the Paradox Valley. 

The Unit is located near the edge of the Colorado Plateau in an area of relatively few historic 

earthquakes. A total of24 earthquakes within 150 kilometers (km) of the injection well site have 

been cataloged since 1850 by the National Oceanic and Atmospheric Administration. The largest of 

these events was a magnitude 5.5 earthquake that occurred in 1960 approximately 11 0 km due east of 

the well site near Ridgeway Colorado. The closest event to the Unit was a magnitude 2.6 event that 

occurred about 16 km north of the site in May 1989. 

The apparent lack of historic seismicity near the Unit may be partly the result of very limited 

seismograph coverage of the area. Before the Paradox Valley Seismograph Network was installed in 

the Unit area in 1983, the closest seismograph stations were several hundred kilometers away. Only 

earthquakes greater than about magnitude 3.4 to 4.0 were routinely located in the area. The region is 

also sparsely populated and, therefore, many earthquakes could have occurred in the Unit area during 

historic times without being noticed or documented. 

Water Resources 

Streams 

The major streams in the Unit area are the Dolores River and its largest tributary, the San Miguel 

River. Both exhibit the large seasonal fluctuations characteristic of streams in southwestern 

Colorado, with very high runoff during the spring because of melting snow in the mountains and 

very low flows after midsummer. Historically, the Dolores River was low and occasionally dry in 

Paradox Valley during the late summer and fall as a result of declining snowmelt runoff and large 

irrigation diversions in the upper part of the basin. However, occasional high flows of very short 

duration occur in the summer and fall from afternoon thunderstorms. As a result of the completion 

in 1988 of McPhee Dam and Reservoir, peak flows in the Dolores River have been reduced and low 

flows have been increased. 

II-5 
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Groundwater 

Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Seeps and springs along the banks and beds of the Dolores River in Paradox Valley are of two 

general types: those witb relatively fresh water, with salinity varying from about 1,500 milligrams 

per liter (mg/L) to 4,000 mg/L, and those with brine of about 250,000 mg/L. Water pumped from 

test wells near the river has a salinity of about 260,000 mg/L (Reclamation, 1978). The brine, which 

is nearly eight times as saline as sea water, consists almost entirely of sodium and chloride, with 

smaller amounts of sulfate, potassium, calcium, and other salts. Heavy metals, particularly iron and 

lead, and nonradioactive strontium are also present in limited amounts. Noticeable amounts of 

hydrogen sulfide gas are released into the atmosphere as the brine surfaces, creating a noxious odor. 

As noted earlier, Reclamation studies indicate that groundwater contributes a total salt load of about 

200,000 tons annually to the river, with daily values ranging from 100 to 1,430 tons. The brine 

evidently accounts for essentially all of the salt, since the seeps of relatively fresh water could 

contribute only about 16 tons per day at a flow rate of 4 cubic feet per second ( cfs ), estimated to be 

the maximum flow of all groundwater entering the river. However, at its estimated flow of 0.2 to 2.1 

cfs and a salinity of260,000 mg/L, tbe brine could produce 170 to 2,170 tons daily. 

Climate 

The climate of the Unit area is characteristic of semiarid southwestern Colorado, with low 

precipitation and humidity, abundant sunshine, moderately high evaporation rates, and wide ranges 

between daily low and high temperatures. The prevailing winds are from the southwest and are 

fairly strong in the spring. 

Reclamation has maintained weather stations at Bedrock since 1975. From 1975 through 1989, the 

average annual precipitation in the Unit area has been about 8 inches. June is normally the driest 

part of the year, and July through October the wettest, primarily because of afternoon thunderstorms. 

Temperatures vary from daytime highs of more than 100 op at Bedrock and 90 op at Dry Creek 

Basin during July to nighttime lows of below -20 op during January. 

Vegetation 

In the Paradox Valley vicinity, vegetation communities vary according to elevation, precipitation, 

soil, land use, and other factors. 

Riparian vegetation composed of cottonwood is found along the Dolores River upstream from the 

brine seeps; below the brine seeps, the riparian community is characterized by tamarisk. Various 

forb and grass species make up the under story in the riparian communities. Marsh areas containing 

rushes are occasionally found along the river; a large wetland area exists where West Paradox Creek 

joins the Dolores River. 

II-7 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

The greatest concentration of agricultural lands occurs in the western portion of Paradox Valley, 

where irrigated pasture, alfalfa, and small grains are the primary crops. 

Extensive semiarid areas with saline soils are located in Paradox Valley. These semiarid areas are 

characterized by greasewood, seablite, winterfat, snakeweed, and other salt- tolerant species. 

Sagebrush occurs on higher slopes throughout the valley and, where overgrazing is not common, 

numerous species of grasses are found. Mesas and higher slopes support pinon-juniper woodlands. 

Flood Plain and Wetland 

A large wetland occurs on West Paradox Creek near the confluence with the Dolores River on its 

west side. Nearer the river, however, the vegetation becomes similar to that found on the east bank, 

predominantly tamarisk, which is low in density and randomly scattered. Flood plain and wetland 

communities along the Dolores River and West Paradox Creek will not be affected by Unit facility 

development. 

Wildlife 

Refer to the Environmental Assessment, Appendix A. 

Fish 

Refer to the Environmental Assessment, Appendix A. 

Endangered Species 

Refer to the Environmental Assessment, Appendix A. 

Cultural Resources 

Refer to the Environmental Assessment, Appendix A. 

II-8 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Chapter Ill 

Paradox Valley Hydrology 

Water Resources 

Surface Water 

Surface water measurements for the Paradox Valley Unit (Unit) were begun in late 1971 with the 

establishment of three stream gaging stations; on the Dolores River at Bedrock where the river enters 

the valley, on the river near Bedrock where the river leaves the valley, and on West Paradox Creek, 

2.6 miles above the creek's confluence with the river. Continuous flow measurements have been 

taken at the two stations on the river and the following discussion is based upon data for the full 

water years of 1972 through 1987. Measurements on West Paradox Creek were discontinued in 1973 

because of difficulties maintaining the station, and records are available only for the full water years 

1972 and 1973. No data have been obtained for East Paradox Creek, which is intermittent and has 

very little effect on the river. Table III-1 shows the average runoff in the vicinity of Paradox Valley. 

October 

November 

December 

January 

February 

March 

April 

May 

June 

July 

August 

September 

Total 

Table 111-1.-Average runoff in the Paradox Valley 

(acre-feet) 

Dolores River 

October 1972 -

September 1983 

At Near 

Bedrock Bedrock 

3,800 4,500 

2,200 2,700 

3.100 3,800 

3,400 3,800 

3,900 4,500 

10,100 11,300 

84,000 87,000 

130,000 132,000 

85,700 87,600 

16,200 17,800 

3.900 4,800 

2,700 3,100 

349,280 363,550 

West Paradox Creek 

1972-73 

III-1 

500 

400 

400 

400 

400 

400 

1,100 

1,400 

900 

300 

200 

200 

6,600 

Dolores River 

October 1983 -

September 1987 

At Bedrock Near 

Bedrock 

8,620 9,500 

8,830 9,700 

7,600 8,200 

7,800 8,900 

7,000 7,900 

28,000 29,400 

114,800 123,800 

138,300 143,600 

82,500 85,000 

13,400 14,300 

12,200 13,300 

7,700 8.700 

436,700 462,300 
Paradox Valley Unit 

Supplemental Definite Plan Repolt/Environmental Assessment 

The recorded flow of the Dolores River at Bedrock averaged 349,300 acre-feet annually during the 

period October 1972 through March 1984 when McPhee Reservoir began storing water. This 

compares to an annual average of299,400 acre-feet for the period 1972-76 used in the 1978 Definite 

Plan Report (DPR). On the basis of the 1972-84 period of record, 86 percent of the annual average 

discharge of the Dolores River at the Bedrock gauge occurred during the months of April, May, and 

June from snowmelt runoff. The peak water year during the period was 1983, when 723,700 acrefeet of water were recorded at the Bedrock gauge. The lowest water year was 1977, when only 

20,700 acre-feet were recorded. The maximum instantaneous discharge at the Bedrock gauge was 

9,280 cfs, which occurred on April30, 1973; the minimum has been no flow, which has been 

recorded on several occasions, including September 13, 1974, and August 15-18, 19782• 

At the gauge near Bedrock, the Dolores River had an average annual flow of363,550 acre-feet over 

the 1972 to 1984 period of record. This varied from a high of 7 48,400 acre-feet in water year 1973 

to a low of38,100 acre-feet in water year 1977. The increase of 14,250 acre-feet in average annual 

flow as the river crosses the valley can be attributed to inflows from West Paradox Creek, East 

Paradox Creek, and fresh and brine groundwater surfacing in the valley. Daily river flows were 

recorded at a maximum rate of 9,500 cfs on April 30, 1973, and a minimum rate of 0.12 cfs on July 

17 and 18,1977. 

The annual flows of West Paradox Creek were recorded at 3,700 acre-feet in water year 1972 and 

9,400 acre-feet in water year 1973 for an average of 6,600 acre-feet. Daily flow rates varied from a 

high of 82 cfs on May 4, 1973, to a low of 2.5 cfs on July 14 and August 23, 24, and 29, 1972. This 

stream does not generally have large variations in flow because the runoff is partially regulated by 

Buckeye Reservoir, a 1,600 acre-foot structure located northwest of Paradox Valley in the upper part 

of the drainage area. Water is stored in the reservoir during high spring runoff and released for 

irrigation in western Paradox Valley during the summer. 

McPhee Reservoir, the principal feature of the Dolores Project (!NT FES 89-1 0), has been predicted 

to decrease flows in the Dolores River in Paradox Valley during the spring runoff months, while 

increasing flows during the summer and fall.' Table lll-1 shows the monthly distribution of flow at 

the two Paradox Valley gauges. The discharge during the runoff months of April, May, and June is 

approximately 77 percent of the annual discharge. The equivalent figure in the pre-impoundment 

period was more than 85 percent. The increase in the flow between the two gauges during the 1984-

88 period is 25,600 acre-feet, which is much greater than the 14,400 acre-foot average before any 

storage in McPhee Reservoir. The large increase would indicate that the basin as a whole received 

much greater than average runoff during the period. Despite any depletions caused by McPhee 

Reservoir, the average annual discharge at the Bedrock gauges is much greater than in the years 

preceding McPhee. These data do not represent the effects of the Dolores Project under full 

development. 

2 R.C. Ugland, J.T. Steinheimer, R.G. Kretschman, E.A. Wilson, and J.D. Bennett 1987. Water Resources Data for 

Colorado, Water Year 1986, Volume 2, Colorado River Basin. U.S. Geological Survey Water Data Report C0-86-2. 

Lakewood, CO. 448 pages. 

3 Data collected since 1984, indicate that this has been the case, although the period of record is short and apparently not 

particularly representative of a long-term hydrologic record. Also, during this period. most facilities to deliver Dolores 

Project water were still under construction so depletions associated with the project did not occur. 

III-2 
Groundwater 

Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Groundwater observations in the Paradox Valley were begun in 1971 with measurements of water 

table levels and piezometric heads in deep aquifers in private wells. To obtain additional 

information on subsurface geology and groundwater conditions, subsequent studies included drilling 

exploratory holes, drilling and pumping from test wells, and installing a network of observation 

wells and piezometers to monitor water table levels and piezometric heads. 

Brine groundwater, which apparently underlies all of Paradox Valley, surfaces in and near the 

Dolores River channel in two general areas extending from the middle of the valley downstream to 

the river's exit from the valley. The depth to brine appears to increase upstream and west of the 

river, as indicated by measurements of brine at about I 00 feet in an existing well located about a 

mile to the west. East of the river along the valley floor, the top of the brine layer is about the same 

level as the river, as measured in Reclamation's observation wells. Although it is impractical to 

directly measure the brine inflow to the river since it occurs as many small springs and seeps, 

Reclamation estimates that it varies from about 0.2 to 2.1 cfs and averages 0.8 cfs, based upon 

measurements of salt loading in the river. The flow exhibits a certain degree of seasonal fluctuation, 

generally reaching its lowest level sometime during spring or summer and its highest level during 

fall and winter. 

A significant layer of comparatively fresh water overlies the brine in western Paradox Valley and is 

pumped from wells for irrigation. Estimated to be at least 100 feet thick about a mile west of the 

Dolores River, the lens gradually thins out closer to the river in the area of the surfacing brine. This 

water also surfaces as seeps and springs in the river and, combined with the brine, results in a total 

contribution to the river of between 1.5 and 4 cfs. 

The brine and freshwater aquifers have a variety of potential recharge sources, including runoff from 

the La Sal Mountains, irrigation return flows from western Paradox Valley, seepage from West 

Paradox Creek, precipitation, and surface and subsurface runoff from the valley walls. Because 

brine evidently circulates over the top ofthe salt core at depths of 650 feet or more before surfacing, 

it probably originates from the farthest recharge source, while the fresh water originates from nearer 

sources. 

Water Quality 

Surface Water 

Water quality data have been collected at the flow measurement gauges located at Bedrock as the 

Dolores River enters the valley and at the gauge near Bedrock as the river leaves the valley. In 

addition to these collection points, intermediate sites were established between these gauges with 

data collection since November 1981. 

Samples collected from the Dolores River gauge at Bedrock had total dissolved solids (TDS) 

III-3 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

concentrations that ranged from 110 to 2,000 milligrams per liter (mg/L). The lower readings 

usually occurred during the high spring runoff and the higher values during late summer and early 

fall. The data indicate the river has an average annual salt load of 141,000 tons as it enters Paradox 

Valley. 

Samples collected at the gauge near Bedrock show a range in TDS from 120 to 20,850 mg/L. The 

annual salt load of the river at the gauge near Bedrock, as the river leaves the valley, has averaged 

343,000 tons, or approximately 200,000 tons greater than the load at the gauge at Bedrock where the 

river enters the valley. 

Using intermediate collection sites between the two gauging stations located at the river's entry and 

exit points from the valley, Reclamation has been able to deduce that this large salt load increase is 

contributed by groundwater and West Paradox Creek. The creek had an average salinity of about 

1,000 mg/L, according to samples collected during the 1971-76 study period. Individual analyses 

ranged from a minimum of260 mg/L during high runoff to a maximum of 1,970 mg/L during low 

runoff. The creek contributes an estimated 7,000 tons of salt-primarily of calcium and 

sulfate-annually to the Dolores River. 

Groundwater 

Reclamation studies indicate that brine groundwater accounts for essentially all the 200,000 tons of 

salt contributed annually to the Dolores River in the Paradox Valley. Samples of brine groundwater 

analyzed by Reclamation have varied in salinity from lows of 117,500 mg/L in an open pit one-half 

mile east of the river, to highs of250,000 mg/L at brine seeps in the Dolores River channel, and up 

to 280,000 to 300,000 mg/L in wells drilled near the river. The variations probably result from 

different degrees of mixing with fresher groundwater in the area. About 94 percent of the TDS are 

sodium and chloride; other salts and heavy metals are present in comparatively small quantities. The 

brine also contains dissolved hydrogen sulfide gas at concentrations of more than I 00 mg/L, which is 

released as the brine surfaces and causes an objectional odor at seepage areas and in open wells near 

the river. An analysis of brine pumped by Reclamation from production wells is shown in table III2. 

III-4 
Table 111-2.-Reclamation lab data averages 1983-86 

(mg/L) 

Well 

number 2E 3E 4E 5E 7E BE 9E 10E 

TDS 254,912 255,780 253,801 252,466 271,489 275,534 250,300 242,483 

EC lab, 232,444 232,726 241,071 239,549 323,177 228,770 239,660 228,147 

pH lab 7.3 7.2 7.3 7.3 7.2 7.2 7.2 7.3 

Calcium, Ca++ 1,429 1,430 1,502 1,446 1,323 1,408 1,444 1,428 

Magnesium, Mg++ 1,619 1,630 1,686 1,751 1,944 1,641 1,628 1,747 

Sodium, Na+ 93,744 93,586 93,376 92,683 100,309 94,963 91,551 89,296 

H H Potassium, K+ 4,042 4,184 4,230 4,351 4,532 4,222 4,191 4,194 H 

I 

lJl Chloride, Cl- 148,360 149,174 147,259 146,533 157,782 149,550 145,923 139,972 

Sulfate, S04- 5,614 5,669 5,643 5,601 5,503 5,662 5,455 5,559 

Bicarbonate, HC03- 202 206 205 197 184 172 210 188 

11E 12E 

210,638 245,492 213,676 227,572 

7.3 7.4 

1,263 1,348 

1,500 1,752 

77,141 90,640 

3,720 4,379 

122,072 141,670 

4,841 5,432 

200 181 

13E 

250,557 224,688 

7.4 

1,252 1,772 

92,543 

4,349 

145,207 

5,338 

186 

10W 

243,653 

234,576 

7.3 

1,353 1,742 

88,953 

4,497 

141,706 

5,300 

199 

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Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

The layer of relatively fresh groundwater overlying the brine west of the river has a salinity ranging 

from 1,400 to 4,000 mg/L, depending upon location and time of year. Water from irrigation wells 

has varied in quality from 1,400 to 3,500 mg/L, and fresh water seeps along the river have varied 

from 1,500 to 4,000 mg!L. The predominant salts are calcium, magnesium, and sulfate, but large 

amounts of sodium and chloride are also found in water samples collected near the river because of 

mixing with the brine. 

Efforts to characterize the immediate effect of brine pumping and disposal on salinity levels in the 

Dolores River have been made during testing of Unit facilities. In general, whenever the brine wells 

are pumped, the TDS level in river samples declines downstream from the brine well field. 

However, because of the many variables associated with quantifYing the exact effect pumping has on 

the river's salinity, such as base salt load conditions, river flows and groundwater flow into the river, 

Reclamation has not considered these characterizations to be a valuable measure of the Unit's 

effectiveness. Instead, Reclamation has determined that any quantity of groundwater brine 

intercepted and disposed of is equal to a quantity that would eventually find its way to the river and 

thereby increase the river's total salt load. Therefore, the Unit's effectiveness is simply measured by 

the amount of brine and corresponding tons of salt pumped from the brine well field. 

During the 233-day test conducted from August 1995 to March 1995, 66,868,070 total gallons of 

brine, with a salinity content averaging 260,000 mg/L, were pumped from the brine well field and 

disposed of in the deep-injection well. The corresponding quantity of salt prevented from entering 

the river was then 72,570 tons for this test injection period. 

Potential for Scale Formation 

The Paradox Valley brine, the resident Leadville formation brine, and cores from the Leadville 

formation were evaluated to determine their chemical compatibility and the potential for scaling 

problems under injection conditions. Experts from the Geological Survey, Oak Ridge National 

Laboratory, and Idaho National Engineering Laboratory directed the necessary studies and developed 

and evaluated alternative solutions. Table III-3 contains an analysis of the formation water. 

The brine to be injected is predominantly a sodium-chloride type brine with high concentrations of 

sulphate and relatively high concentrations of potassium, magnesium, and calcium. The brine is 

close to saturation with calcium-sulphate at groundwater temperature. However, because the 

solubility of calcium-sulfate decreases with increasing temperature, the injected brine would become 

highly supersaturated under injection conditions of approximately 240 to 250 degrees Fahrenheit. 

The primary injection zone is the Leadville formation, consisting mainly of calcite and dolomite, 

with dolomite predominant in the more highly fractured and weathered zones. Because the 

concentrations of magnesium in the injected brine are relatively high and the thermodynamic 

constraints are favorable, the dissolved magnesium would react with the calcite portions of the 

injection formation to form dolomite and add calcium to solution. The additional calcium would 

increase the potential for calcium-sulfate scale formation. 

III-6 
pH 

Mg 

Ba 

Br 

B 

Na 

Ca 

Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Table 111-3.-Chemical composition of formation water 

Paradox Valley injection well (sample 88PVB-124) 

5.42 

1,200 mg/L 

8.32 mg/L 

257 mg/L 

19.1 mg/L 

70,000 mg/L 

10,900 mg/L 

Mn 

HCO, 

TDS 

K 

Sr 

Fe 

so, 

1.13 mg/L 

148 mg/L 

218,000 

2,100 mg/L 

433 mg/L 

2.1 mg/L 

454 

The resident formation brine is also predominantly a sodium-chloride type brine but with a much 

higher calcium concentration, a much lower sulfate concentration, and a somewhat lower magnesium 

concentration than the injected brine. Mixing of the brines under injection conditions would result in 

increased formation of calcium-sulfate scale due to the high sulfate concentration in the injected 

brine and the availability of additional calcium. 

Numerous alternatives to prevent the formation of calcium-sulfate scale were developed and 

evaluated. Several commercially available scale inhibitors were evaluated under injection conditions 

but none appeared to be effective in preventing scale formation. Methods to remove sulfate from the 

brine before injection were evaluated but did not appear feasible due to the required addition of large 

quantities of chemicals to initiate precipitation and the required disposal of large volumes of 

precipitate. The selected alternative incorporated in the project plan consists of preventing mixing of 

the formation brine and injected brine, and diluting the brine to be injected to lower the sulfate 

concentration. 

To prevent mixing of the formation brine and the injected brine, preliminary injection tests were 

conducted using fresh water. This provided a buffer between the resident brine and the brine that 

was later injected to prevent any mixing from occurring near the well bore. Intermediate injection 

tests were conducted using a mixture of two-thirds fresh water and one-third brine. This dilution 

provided the necessary chemistry to promote dolomitization of calcite (useful to increase porosity) 

near the well bore without precipitation of calcium-sulfate. Later injection tests used a mixture of 

two-thirds brine and one-third fresh water, a dilution sufficient to prevent precipitation of calcium 

sulfate due to increased temperatures of injection conditions. The project plan is to operate with this 

mixture until a more feasible method of sulfate concentration reduction is developed. 

III-7 

General 

----- 

Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Chapter IV 

Unit Development 

The Paradox Valley Unit (Unit) is designed to control salinity in the Dolores River by pumping brine 

groundwater from a well field located along the river in Paradox Valley to prevent it from surfacing 

in the river bed. The 1979 Definite Plan Report (DPR) provided for disposal of 5 cubic feet per 

second ( cfs) of brine by pumping it through a series of lift stations and pipelines to an evaporation 

reservoir some 20 miles southeast of the well field. After the 1979 DPR plan was formulated, local 

groundwater studies conducted by Reclamation, indicated that disposing of 1.5 to 2.0 cfs of brine 

would probably meet the Unit's goal of reducing the salt load in the Dolores River by 90 percent, or 

180,000 tons per year. The geology of the area indicated that this reduced quantity of brine might be 

disposed of by deep well injection, a previously identified preferable alternative for disposal of the 

brine. Consequently, an access road, brine treatment facility, brine transfer pipeline, surface 

injection facility, and test injection well were constructed to verity the feasibility of disposing of the 

brine by deep well injection. Testing of the well is complete, with results indicating that this method 

of brine disposal is physically and economically feasible. 

Future-year construction of the additional facilities needed to realize the Unit's original salinity 

reduction goal of90 percent is not foreseeable, due to construction funding limitations. To realize a 

significant salinity control benefit from the present investment, the test injection facility would be 

operated as currently constructed. The Bureau of Reclamation (Reclamation) estimates that the test 

injection facility, operated as a permanent facility, would effectively remove up to 128,000 tons of 

salt annually, or about 64 percent of the salt now entering the Dolores River in Paradox Valley. This 

estimate is based on the present facility's operational guidelines of limiting injection to a 70 percent 

brine/30 percent freshwater mixture at the rate of 400 gallons per minute (gpm), with a plant factor 

goal of 80 percent. Reclamation's Western Colorado Area Office would administer the facilities for 

salinity control and be responsible for their annual operation, maintenance, and replacement. 

Project Features 

Brine Well Field 

Production Wells 

Twenty-four brine production wells were constructed as part of the design data collection and 

verification program. Twenty-three of the wells were drilled into the alluvial aquifer of sand and 

gravel to depths of between 48 and 77 feet. The remaining well extended into cavities in the residual 

gypsum cap to a total depth of about !55 feet. The diameter of the wells varied from 8 to 12 inches, 

with the lower 15 to 40 feet consisting of well screens to allow the brine groundwater to enter. 

Gravel packing was placed around each well screen to stabilize the wells and prevent fine sand from 

IV-1 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

entering the screens. Submersible electric pumps, varying in capacity from 0.03 to 0.3 cfs, were 

installed in the wells along with brine level monitors to aid in optimizing production from the 

individual wells. 

Data collected during the brine well field testing program indicated that only I 0 of these 

wells-located on the east side of the river-would be required to supply the 1.5 cfs needed to 

achieve the Unit's original goal of reducing the salt inflow to the Dolores River by 180,000 tons 

annually. As a result of this information, these I 0 wells were modified and used as permanent brine 

wells during the injection well test. Modifications included installation of additional pump control 

equipment, upgraded access roads, construction of high-density polyethylene pipelines to connect 

each well to the surface treatment facility, and permanent security fencing. Thirteen of the original 

24 brine wells, on both sides of the river have been or will be plugged and abandoned. One well, on 

the east side of the river and not connected to the surface treatment facility, would be kept available 

for future contingencies. 

In addition to the production wells, 68 groundwater monitoring wells have been drilled on both sides 

of the river, cased, and equipped with security caps. Water levels are checked in the wells during 

project operations and the data are used to determine what effect pumping the brine production wells 

has on the water table, how the freshwater and brine interact, and how brine moves within the 

aquifer. From this information, the most effective pumping rates and patterns for operating the 

production wells are established. These wells may be equipped with automatic recorders in the 

future as a refinement to allow continuous measurements and operation adjustments. 

Injection well testing used about .62 cfs of brine pumped from various combinations of the I 0 

production wells on line. Because this volume of brine was well below the proven 1.5 cfs capability 

of the 10 wells, the present well field should be adequate for long-term operation. Long-term 

operation of the facility and subsequent well field monitoring data would enable the construction of a 

complete brine well field groundwater model. This model would develop optimum pumping 

schemes and identify well field modifications which would maximize salinity control benefits from 

the Unit as constructed. 

Monitoring Welts 

The monitoring wells are of two different categories. The first category consists of 39 shallow 

observation wells, generally about 25 feet deep and 1.5 inches in diameter, with 10-foot well screens 

placed between I 0 and 25 feet deep to allow groundwater to enter. These wells are used to observe 

the water table and to measure changes in conductivity, an indicator of the interface between the 

brine and freshwater. The second category consists of 29 deep wells, each containing three pipes. 

Each pipe extends to a different depth and has a section of well screen at the bottom. A shallow 

pipe, screened from the 5- to 25-foot zone, is used to observe the water table and the point at which 

the brine and freshwater interact. A second pipe, screened near the base of the alluvial aquifer 

(between 56 and 120 feet deep), is used to measure the brine piezometric head in that zone. A third 

pipe, screened in the gypsum bedrock between 215 and 300 feet deep, is also used to measure the 

piezometric head of the brine. A grout seal has been placed between the pipes to prevent water from 

the three different zones from intermixing. 

IV-2 
Surface Treatment Facility 

Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

The brine from individual well field production wells is piped to a central surface treatment facility 

adjacent to the well field on the east side of the Dolores River. This facility, constructed as part of 

the deep well injection testing program. consists of a 1.5-acre site where process equipment is 

housed in a prefabricated metal building with concrete masonry exterior walls. At this location, 

brine from the individual wells is combined into a single stream, then filtered and transferred to one 

of two 25,000-gallon buried storage tanks. A 60-horsepower turbine pump in each tank pumps the 

brine through a second filter and to the injection facility. The treatment facility also serves as the 

control center for the individual production wells. Equipment to monitor the rate of pumping, brine 

well water levels, pressure, and brine quality for each well is located within the facility along with 

program logic control devices to automatically control individual well operation. With proper 

maintenance, the equipment located within this facility is adequate to allow its use for long term 

brine injection without additional construction. 

Brine Transfer Pipeline 

Brine from 25,000-gallon tanks located at the treatment facility, is carried to the injection facility 3.5 

miles to the south, in a buried, 10-inch high-density polyethylene pipeline. This pipeline was 

constructed for use during the deep well injection testing program and is satisfactory for permanent 

service. 

Brine Injection Components 

Brine Injection Facility 

The Brine Injection Facility was also constructed as part of the deep well injection testing program. 

The injection facility is located adjacent to the injection well on the 6.5-acre, graded, and fenced site 

that was used during the injection well drilling. Components of the facility consist of a 50-by-80-

foot prefabricated metal building with concrete masonry exterior walls for housing controls and 

injection pumps, a water treatment plant with associated storage tanks and ponds. and a Well 

Annulus Monitoring System (W AMS). 

Brine from the brine transfer pipeline enters one of two 25,000-gallon buried, pressurized storage 

tanks at the injection facility. One tank is required for operation and the second serves as a backup to 

allow for maintenance during continuous operations. Fresh water which dilutes the brine to 70 

percent (70 percent brine, 30 percent fresh) is added at the tank location to control calcium sulfate 

precipitation. Equipment necessary for additional chemical treatment has been installed at the tank 

location, but operations to date have required only the addition of a chemical oxygen scavenger to 

help reduce the corrosive effects of the brine on pumping equipment. 

The tanks are equipped with 20-horsepower turbine pumps to transfer the diluted brine through a 

filter and through pressure-, temperature-, and flow-monitoring equipment to the intakes of the four 

injection pumps. These 350-horse power, alternating current, 100 gallons per minute (gpm) (each) 

IV-3 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

positive displacement pumps are used to increase injection pressures up to 5,000 pounds per square 

inch (psi). These large pumps can be operated singly or in tandem, allowing for maintenance. The 

pressurized brine flows to the injection well through a 5-inch-diameter nickel-alloy pipeline. During 

the injection well test, deficiencies in injection facility equipment caused interruptions in the test 

schedule. The deficient equipment has been modified and tested in continuous, 24-hour operation 

for 8 months. With proper maintenance, the presently constructed injection facility could be 

operated at an SO-percent plant factor as a permanent facility for the injection well. 

Water Treatment Plant 

The water treatment plant, located at the injection facility, pumps water from the Dolores River and 

provides the water necessary for diluting brine to 70 percent. The plant also provides facility service 

water. The plant has a 200-gpm capacity and consists of a lined flocculation pond; filter tanks; six 

12,500-gallon, above-ground, treated-water storage tanks; a facility service water chlorination 

system; and a lined backwash pond. 

Well Annulus Monitoring System 

The Well Annulus Monitoring System (W AMS) consists of a fluid storage tank, triplex positive 

displacement pump for maintaining pressure, and electronic monitoring equipment to automatically 

adjust the pressure. The system is designed to maintain fluid pressure in the annulus between the 

wells exterior casing and the injection tubing down to the top of the injection zone. By pressurizing 

the annulus fluid, brine is prevented from entering the annulus space and the injection well can be 

operated. The annulus was originally designed to be filled with a static fluid which could be 

monitored with pressure gauges to detect leaks in the injection tube. Immediately after construction, 

a leak was detected in the polished bore receptacle at the top of the injection zone. Due to the high 

cost of repairing this defect, a decision was made to maintain pressure on the annulus fluid which 

would exceed the injection pressure. 

Injection Well 

Pressurized 70-percent brine from the injection facility enters the injection well at ground surface 

level and is carried through upper geologic formations in a 5-112-inch-diameter Hastelloy C-276 

injection tube to a perforated injection liner which extends through the geologic formations identified 

as the injection zone. The brine leaves the injection liner and is permanently disposed of within the 

surrounding injection formation which serves as the injection reservoir. 

Test Injection Well No.I was drilled to a depth of 15,857 feet. The drill hole was cased with 30-

inch-diameter casing through the surface formations and with 9-5/8- inch casing to the top of the 

injection formation at 14,068 feet. A perforated 5-1/2-inch-diameter, Hastelloy C-276 injection liner 

extends through the injection formation to the well's bottom depth. While the primary injection zone 

formation is Mississippian Age Leadville limestone, which lies directly below the salt formation, the 

injection zone extends through Devonian Age formations and into the Precambrian Formation. 

IV-4 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

This well and its injection reservoir formation have successfully disposed of a 70-percent brine at the 

rate of 400 gpm during the injection well test. The results of data collected during the injection test 

indicate that the well and its associated surface equipment would be capable of disposing of similar 

quantities of brine for at least I 0 years and perhaps indefinitely.' Should the injection formation 

begin to refuse acceptance of the brine, the pressure necessary to inject would increase. This would 

make the present equipment incapable of performing, or the facility would have to be operated at 

reduced injection rate that would no longer be cost effective. Should this situation occur, the Unit's 

future participation in the salinity control program would be examined and the Unit's facilities either 

abandoned or replaced with equipment needed for continued operation. 

Electrical Power 

A 69-kilovolt (kV) powerline, connecting existing lines near Colorado Highway 90 with the injection 

facility 1.2 miles to the south, was constructed for the injection well testing. A substation and 

transformer yard constructed near the injection facility enclosure compound is the terminal end of 

the line. The alternating current obtained from the transformers is converted to direct current (DC) 

power for use by the injection pumps with three silicone controlled rectifiers installed within the 

injection facility building. 

The presently constructed power system is adequate to operate the Unit as a permanent injection 

facility. 

Access Road and Office Facility 

As part of the injection well test, a 20-foot-wide, 1.2-mile-long, gravel access road was constructed 

from Colorado Highway 90 to the injection well site. At the same time, at a site about .8 mile from 

and adjacent to the highway, a !-acre parcel was graded, graveled, fenced, and equipped with water, 

power, sewer, and telephone utilities for mobile housing units which served as an office and living 

quarters during construction. The access road and office compound are adequate as constructed for 

permanent injection operation needs. 

Seismic Monitoring Network 

The Paradox Network is a IS-station, high-gain, radio-telemetered, seismic network operating near 

the Unit (see figure 1 of the Environmental Assessment). It was originally installed with the primary 

objective of determining the background level of naturally occurring seismicity near the deep well 

injection site before fluid injection began. Other associated goals during the preinjection phase 

included determining the state of stress in the crust and the corresponding likelihood of earthquakes 

being induced by injecting salt brine. The network would be continuously operated and maintained 

as presently configured for as long as the injection well is used. This precautionary provision would 

4

Envirocap Report of Evaluation 

IV-5 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

ensure the Unit is operated responsibly with respect to any seismicity in the region.' 

Beginning 50 km east of the Paradox Network is the Ridgway Seismograph Network (Ridgway 

Network), an array of seven stations comprised of instrumentation identical to that used in the 

Paradox Network. Recorded and processed simultaneously with data from the Paradox Network, the 

Ridgway Network data enhances the Paradox Network analysis. The Ridgway Network expands the 

seismograph coverage of interest in defining earthquake hazards for the Unit and provides important 

data necessary to determine focal mechanisms of earthquakes near the Unit. 

Dolores River Monitoring System 

A river monitoring system was installed by Reclamation during the design data acquisition program 

and has been used to assess changes in streamflow and water quality occurring as a result of 

removing the brine groundwater. The system includes four electrical conductivity meters installed 

along the east side of the Dolores River within and upstream and downstream from the well field. 

These meters operate automatically to provide a continuous record of any changes in conductivity as 

the river flows through the valley. The conductivity readings, in turn, are indicators of the amount of 

salt in the water flowing past the meters and provide an estimate of the effect of brine pumping on 

reducing the salt load of the river. The other features of the monitoring system include two gauging 

and water-quality monitoring stations located where the Dolores River enters the valley upstream 

from the Unit and where it exits the valley downstream from the Unit. These stations provide a 

continuous record of flows in the river and continuous conductivity readings. Water samples are 

taken from these two locations and analyzed for exact water quality data. The system, as 

constructed, can be operated with the Unit's other features to provide information necessary for 

effective operation. 

5 Analog seismic signals detected at each station are transmitted continuously via VHF or UHF radios, microwave, and 

telephone circuits to a central recording facility in Denver, Colorado, where the signals are digitized and interrogated. 

Suspected earthquakes are stored for future processing after being automatically reduced and analyzed for origin time, 

hypocentrallocation, and magnitude. Results from this initial process are typically available within 3 to 5 minutes from 

when the event occurs. The present network configuration can determine epicentrallocation to a precision of +/-0.1 to 0.2 

km and focal depth to less than+/- 0.5 km for earthquakes that may occur near the injection well. Earthquakes as small as 

magnirude 0 can be detected and located within the interior of the Paradox Network. 

IV-6 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Protection of Unit Works from Flood Hazards 

The only project feature located in a flood hazard area is the brine well field. This feature has been 

designed and constructed to be protected from a l 00-year flood event by locating surface electrical 

and mechanical equipment above the event's highest water level. Such a flood would have no effect 

on the below-ground-level components of the well field. 

Water Rights, Permits, and Augmentation Plan 

Reclamation obtained a conditional water right for 4.94 cfs with an appropriation date of April 1972 

(Case No. W3549). In 1986, Reclamation obtained approval for Changes in Water Rights and a 

Plan for Augmentation in U.S. District Court, Water Divisions 4 and 7 (Cases No. 4-83CW45 and 7-

83CW14; respectively). The augmentation plan would allow water to be stored in McPhee Reservoir 

and released to replace depletions in the Dolores River resulting from out-of-priority pumping of the 

brine production well field. In addition, Reclamation has obtained a water right for 10 gpm for 

domestic purposes for use at the Unit surface treatment and injection well facilities. 

Reclamation has obtained a Class V injection well permit pursuant to Underground Injection Control 

Regulations of the Environmental Protection Agency. 

Mineral Rights 

Although Reclamation has determined that brine pumped by Unit is not a mineral, one mineral-right 

holder in the vicinity did contact the agency with the concern that operation of the injection well 

would affect his ability to use the brine. Reclamation was able to agree with this holder to provide a 

source of brine at the brine well field, provided that no salt or brine would be allowed to enter the 

river or groundwater system as a result of this use. Mineral rights in the vicinity of the injection well 

were acquired with the purchase of the 388 acres surrounding the injection well facility. 

Rights-of-Way 

Reclamation has a rights-of-way grant from the Bureau of Land Management (BLM) (C-27756) 

covering facilities in the brine collection well field, the brine storage pond area, and seismic stations. 

Reclamation has received an amendment to this grant for the following: (1) a 100-foot-wide, 2750-

foot-long right-of-way on BLM land located north of Colorado Highway 90; (2) a 100 -foot-wide, 

310-foot-long right-of-way located south of Colorado Highway 90; and (3) two additional seismic 

stations. 

Reclamation has obtained permits from the U.S. Forest Service and the Utah State Forest Service to 

place seismic stations and one repeater station on lands administered by these agencies. 

Reclamation has acquired 565 acres in fee title and 150 acres of easements from private landowners 

for the remainder of the Unit features. No additional rights-of-way are anticipated for permanent 

IV-7 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

operation of the Unit as it is currently constructed. 

Cultural Resources Program 

Refer to the Environmental Assessment, Appendix A. 

Wildlife Program 

Refer to the Environmental Assessment, Appendix A. 

Operation and Maintenance 

General 

The facilities constructed to conduct the deep well injection test would be operated and maintained 

by Reclamation as the Unit's participation in the Colorado River Basin Salinity Control Project 

(CRBSCP). The components, including the brine production wells, monitoring system, surface 

treatment facility, brine pipeline, brine injection facility and injection well would be operated from 

the control room located at the injection facility by an operator, assistant operator, and automatic 

control equipment. Information on the operating conditions of these facilities and malfunction 

warnings would be telemetered to the control room so that adjustments and maintenance can be 

made promptly. In addition to periodic checks and maintenance of equipment, normal operations 

would include readings at the monitoring wells, stream gauging stations, and water-quality stations 

in Paradox Valley. 

Most equipment replacements for the Unit would be part of normal maintenance. The facilities 

constructed for the deep well injection test were equipped with backup or standby equipment to 

allow for continuous operations when repairs to malfunctioning equipment is required. Using this 

same equipment for permanent operations, continuous or near-continuous injection of brine could 

occur year round. The individual brine wells in the well field can be shut down for repairs and 

maintenance without affecting the other wells, making continuous brine production possible. 

Power 

The power requirements of the Unit would be approximately 7 million kilowatthours (kWh) 

annually, with a demand requirement of 1,000 kilowatts (kW). These requirements are based on 

historical data from the deep well injection test with the Unit injecting I cfs, an SO-percent operating 

factor, and the present Colorado River Storage Project (CRSP) rates of 8.9 mills per kWh and $3.83 

per kilowatt-month, with a wheeling rate equivalent of approximately 11.5 mills per kWh. 

IV-8 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Unit Costs 

Construction Costs 

With completion of the deep well injection test, construction of the Unit is considered complete. 

Additional construction, if needed to optimize production or increase the Unit's effectiveness for 

salinity control, would require additional appropriations. The construction cost for the presently 

constructed facilities is capped at $68,736,170. Return from this investment can be realized without 

expenditure of additional construction dollars by operating the test injection facilities as the 

permanent facility. 

The life of the Unit would be dependent upon the injection well reservoir capacity, which is 

unknown. When the present injection reservoir is filled, pumping pressures and related costs would 

increase. Ultimately, the costs of operating the Unit could make use of the facilities impractical, at 

which time the Unit would be abandoned or revitalized with a second injection well. The asconstructed costs of the present facilities are shown in table IV -1. 

Table IV-1.-Deep well injection (proposed action) estimated costs 

(October 1994 dollars) 

Actual cost Estimated 

Description through FY941 future costs2 

Brine well field 3,683,310 0 

Brine pipeline 1,851,362 0 

Surface treatment facilities 9,227,663 1,575,000 

Deep injection well 28,012,091 1,075,000 

Permanent operating facilities 40,067 0 

Operation and maintenance housing 36,141 0 

Service facilities 652,987 0 

Depreciation and salvage <570,846> 0 

Investigations and abandoned works through 1986 19,238,543 0 

Emergency reserve O&M fund 455,600 0 

Wildlife mitigation 60,136 0 

O&M during construction 2,208,415 0 

Other noncontract costs' 1,190,701 0 

Total cost 66,086,170 2,650,000 

Annual equivalent cost of construction4 

Annual operation, maintenance, replacement, and 

power costs 

Total annual costs 

Annual cost per ton of salt removed' 

IV-9 

Total cost 

3,683,310 

1,851,362 

10,802,663 

29,087,091 

40,067 

36,141 

652,987 

<570,846> 

19,238,543 

455,600 

60,136 

2,208,415 

1,190,701 

68,736,170 

5,457,714 

3,300,000 

8,800,000 

69 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

1 From PF-28 (working version) - revised date: 12/28/94. 2 Based on FY95 estimate of $2,350,000 and FY96 estimate of 300,000. (75-percent surface facilities and 

25-percent injection well). 3 lncludes actual office general expense, materials, and equipment, etc., from PF-28. 4 Based on 50-year life at 7.75-percent interest rate. 5 Based on estimated 128,000 tons of salt removed per year. 

Annual Operation, Maintenance, and Replacement Costs 

The annual operation, maintenance, and replacement (OM&R) costs ofthe Unit are estimated at 

about $3.3 million annually for operating the existing facility (based on injection test data and 1994 

prices). 

Financial and Economic Analysis 

Benefits 

Benefits from the operation of the test injection well facility as a permanent injection well facility 

would accrue to users of Colorado River water both within and outside the Colorado River Basin. 

Presently, the indexed annual value is $334 for each ton of salt removed.' Salt reduction expected 

from operating the presently constructed facility is 128,000 tons annually, resulting in annual 

benefits of $42,752,000. 

Water users outside the Lower Basin would also benefit from the salinity reduction in Paradox 

Valley and from other units of the basin-wide salinity control program. Some of the benefits would 

occur directly, such as those that would be realized by users of water for culinary purposes and for 

irrigation. Additional benefits would occur indirectly, particularly those accruing to users of fossil or 

other fuels processed with Colorado River water. Because of the widespread and diffuse nature of 

these benefits, however, they cannot be fully quantified in monetary terms. 

Cost Per Ton of Salt Removed 

The annual cost for each ton of salinity reduction for operating the present facility as the Unit's 

contribution to the salinity control effort is shown in table IV -1 and is based on the annual equivalent 

cost and an estimated annual reduction of 128,000 tons of salt. The annual equivalent cost consists 

of the sum of the annual value of the capital investment amortized over 50 years at a 7.75 percent 

interest rate. 

Table IV -2 displays the cost allocation and repayment summary for the presently constructed 

facility. The reimbursable amount for construction and OM&R would be $2,180,000 annually. 

Annual nonreimbursable costs total $6,577,000. 

6 Derivation of the interim salinity value of $257 (1986 dollars) per ton is outlined in a Reclamation memo, Interim 

Salinity Control Benefit Value (Salinity Control Coordination, May 4, 1993. This figure, which is based on direct benefits 

only, \Vas indexed to January 1993 dollars ($334) using the consumer price index. 

IV-10 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Table IV-2.-Cost allocation and repayment summary 

deep well injection (proposed action) 

Cost allocation 1 

Total construction cost and annual OM&R 

Reimbursable 

Lower Basin Fund 

Upper Basin Fund 

Total reimbursable costs' 

Annualized reimbursable construction cost 

Repayment 

Total annual reimbursable (construction plus OM&R) 

Nonreimbursable 

Total nonreimbursable costs 

Annualized nonreimbursable construction cost 

Total annual nonreimbursable (construction plus OM&R) 

Total annual cost (reimbursable plus nonreimbursable) 

1 Total cost allocation includes interest during construction. 

October 1994 

construction costs Annual OM&R costs 

68,736,000 3,300,000 

14,510,000 

2,180,000 

17,070,000 

1,355,000 

2,180,000 

51,666,000 

4,102,000 

6,577,000 

8,758,000 

701,000 

124,000 

825,000 

2,475,000 

2 Public Law 93-320, section 205, states that 75 percent of the costs will be nonreimbursable. The other 

25 percent is divided between the Lower Colorado River Basin Development Fund and the Upper Colorado River 

Basin Fund based on benefits to be derived by each basin for the use of water of improved quality, causes of salinity, 

and availability of revenues, provided that costs allocated to the Upper Basin shall not exceed 15 percent of the costs 

allocated to the Upper and Lower Basin funds. The costs to which the percentage division is applied do not include 

$456,000 of pre-authorized costs which are nonreimbursable pursuant to Public Law 92-149. 

Cost Allocation and Repayment 

In accordance with the Colorado River Basin Salinity Control Act, 75 percent of the total costs of 

construction and OM&R for each ofthe four authorized units of the salinity control program would 

be nonreimbursable. The remaining 25 percent would be reimbursable and would be allocated 

between the Lower Colorado River Basin Development Fund and the Upper Colorado River Basin 

Fund, with no more than 15 percent of the reimbursable costs allocated to the Upper Basin fund. The 

authorizing legislation also directs that the Secretary of the Interior, after consulting with 

representatives of the Basin States who form the Colorado River Basin Salinity Control Advisory 

Council, make the final allocation of reimbursable costs on the basis of the benefits to be derived in 

each basin, the causes of salinity, and the availability of revenues in the two basin funds. The 

reimbursable costs would be repaid without interest within a 50-year period after the Unit became 

operational. The nonreimbursable costs and the reimbursable costs to be repaid from each basin fund 

IV-11 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

are shown in table IV-2 based upon an allocation of 15 percent of the reimbursable costs to the 

Upper Basin fund and 85 percent to the Lower Basin fund. The costs of the cultural resources 

program would be nonreimbursable under Public Law 93-291. 

The Secretary of the Interior is authorized by the Salinity Control Act to increase the rates charged 

for electricity generated by the CRSP to provide revenues for repayment of the Upper Colorado 

River Basin's share of the reimbursable costs of the Paradox Valley Unit and other units authorized 

by the Act. Rates chargeable to cover such costs were included in a rate schedule announced by the 

Assistant Secretary of the Interior. The nonreimbursable portion of the annual OM&R costs would 

be funded by annual Congressional appropriations. 

IV-12 
Introduction 

Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Chapter V 

Alternatives 

As presented in the Paradox Valley Unit (Unit) 1978 Definite Plan Report (DPR), the Bureau of 

Reclamation (Reclamation) studied several methods of reducing the salt contribution from Paradox 

Valley to the Colorado River system. Several of the options studied were based on the presumption 

that 5 cfs of brine must be pumped and disposed of to achieve the Unit's 90-percent salt loading 

reduction goal. The 1978 DPR concluded that the Radium Evaporation Pond Alternative would be 

the preferred alternative, because (I) the geologic stratum into which the brine would be pumped, 

under the injection well alternative, would not accept 5 cfs of brine and (2) the economics of the 

other alternatives made them undesirable. However, the 1978 DPR did state that the deep well 

injection alternative would warrant further investigation to determine its feasibility if the pumping 

rate required to achieve the Unit's goal was found to be as low as 2 cfs. 

Subsequent testing of the brine well field showed that a pumping rate of 1.5 cfs was adequate to 

achieve the Unit's salinity reduction goal. As a result, the deep well injection method of disposal was 

thoroughly investigated and tested. The test has concluded that the test facility used to investigate 

deep well injection is capable of disposing of about 128,000 tons of salt, or 64 percent of the total 

salt entering the Dolores River in the Unit area. 

In addition to the Proposed Plan, three alternatives are discussed in this chapter: (I) a No Action 

alternative; (2) construction of a second injection well, which would allow the Unit to meet its 

original 90-percent salinity reduction goal; and (3) construction of a downsized Radium Evaporation 

Reservoir capable of disposing of the entire 1.5 cfs of brine necessary to achieve the Unit's original 

goal of a 90-percent salinity reduction, or 180,000 tons of salt. 

Proposed Action-Continue Operation of Test Injection Well 

The proposed action is to continue operating the already-constructed test injection well facility 

described in chapter IV as the Unit's permanent contribution to the CRBSCP. 

No Action Alternative 

The No Action Alternative would be to abandon the present facility and discontinue efforts to control 

salinity from the Unit area. Approximately 200,000 tons of salt would enter the Dolores River 

annually from the brine water inflows located in the Paradox Valley. Other methods of limiting the 

salinity of the Colorado River would be needed to meet the goals of the Federal salinity control 

V-1 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

program, and no benefit would be realized from the nearly $69,000,000 investment in the Unit to 

date. Abandoning the present facility would require an additional $300,000 in estimated 

construction costs to plug the injection well, most of the brine production wells, and observation 

wells in the brine well field. Plugging these wells would be necessary because existing regulations 

do not permit wells to remain open if they are not used and maintained. The costs of dismantling 

structures and performing environmental restoration have not been determined and are not included 

in the plugging cost. 

V-2 
PARADOX VALLEY UNIT 

FINAL ENVIRONMENTAL ASSESSMENT 

Appendix A 

Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

ENVIRONMENTAL ASSESSMENT 

CONTENTS 

Page 

Introduction .................................................................. 1 

Chapter 1 - Purpose and Need for Action ........................................... 6 

Chapter 2 - Alternatives 

Proposed Action ............................................................ 6 

No Action Alternative ....................................................... 6 

Chapter 3 - Affected Environment and Environmental Consequences ..................... 7 

Surface Water Resources ..................................................... 7 

Groundwater Resources ...................................................... 8 

Water Quality .............................................................. 9 

Vegetation ............................................................... 10 

Wetlands and Riparian Habitats ............................................... 12 

Fisheries Resources ........................................................ 13 

Wildlife ................................................................. 15 

Threatened and Endangered Species ........................................... 19 

Seismicity and Tectonics .................................................... 21 

Chapter 4 - Consultation and Coordination ......................................... 31 

Development of Proposed Plan ............................................... 31 

Consultation and Coordination (Environment) ................................... 31 

Results and Implementation (Environment) ..................................... 31 

Consultation and Coordination (Endangered Species) ............................. 32 

Results and Implementation (Endangered Species) ................................ 33 

Indian Trust Assets ........................................................ 33 

Cultural Resources ......................................................... 3 3 

Environmental Justice ...................................................... 34 

Environmental Commitment Plan ............................................. 34 

i 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Public Involvement and Information ........................................... 35 

References Cited .......................................................... 36 

List of Preparers ........................................................... 3 7 

TABLES 

III-I List ofNon-Native Fish Species ............................................ 13 

III-2 List of Native Fish Species ................................................ 14 

III-3 Summary of Potential Impacts ............................................. 20 

FIGURES 

Figure 1- Pre-injection earthquake hypocenters ..................................... 25 

Figure 2- Hypocenters located above the top of the Leadville formation .................. 26 

Figure 3- Cumulative injection volume and relative earthquake hypocenters ............... 27 

Figure 4- 3-D Projection- hypocenters above the top of the Leadville formation ........... 28 

Figure 5- Planar alignment - hypocenter subset representation .......................... 29 

Figure 6- Mohr circle diagram showing inferred, bottom of injection well ................ 30 

ii 
~-------

Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 
Introduction 

Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

The Paradox Valley Unit (Unit) of the Colorado River Basin Salinity Control Project is located 

in southwestern Colorado and is designed to control natural brine inflows into the Dolores River. 

The Valley overlies a fractured gypsum cap that covers a formation of salt and salt-rich shale that 

begins at a depth of about 600 to 1,000 feet and extends downward for about 14,000 feet. The 

Dolores River picks up an estimated 205,000 tons of salt armually as it crosses the valley. This 

salt comes primarily from the surfacing of natural brine groundwater. The purpose of the Unit is 

to intercept the brine and prevent this salt load from entering the Dolores River and eventually 

degrading the water quality of the Colorado River. 

Reclamation began studies at Paradox Valley in 1971. By 1979, a Definite Plan Report and 

Final Environmental Statement had been approved recommending a plan that would prevent 

approximately 90 percent of the natural brine inflow (185,000 tons of salt armually) from 

entering the Dolores River. The recommended plan consisted of constructing a series of shallow 

brine production wells adjacent to the river, pumping the wells at a collective rate of 5 cubic feet 

per second (cfs) to intercept the brine, transporting the brine via a 21-mile-long pipeline and 

eight pumping stations to Dry Creek Basin, and disposing of the brine by evaporation in the 

3,630-acre Radium Evaporation Pond. Deep well injection was one of the alternative brine 

disposal methods discussed briefly in the environmental statement. This Alternative was 

eliminated from further study because the proposed 5-cfs disposal rate was estimated to be higher 

than the geologic formations could absorb. The Region VIII Office of the Environmental 

Protection Agency reviewed the 1978 Draft Environmental Statement and stated that it "believes 

that disposal by deep well injection is the environmentally preferred solution and therefore 

should be seriously investigated for brine disposal" (BOR, 1978). 

Test brine well field facilities were constructed and a verification program was initiated in 1978. 

Investigations and testing proved that pumping the brine well field was a highly effective method 

for controlling the brine inflow to the river and indicated a pumping rate of 1.5 to 2 cfs instead of 

the originally proposed rate of 5 cfs, would achieve the Unit's goal. As a result, the brine 

disposal plan was re-evaluated and the alternative of deep well injection appeared to be more 

feasible. 

A consulting engineering firm completed a feasibility study of deep well injection and concluded 

it to be technically, economically, and environmentally feasible. An injection testing program 

was designed, test facilities were constructed, and the testing program was initiated. 

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Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Data collected from the injection test program confirmed that injection is a physically, 

economically, and environmentally feasible method of brine disposal. The test program also 

determined that two injection wells would be necessary to dispose of the required brine 

production of 1.5 to 2 cfs. In 1989, Reclamation formulated an alternative project plan which 

incorporated 24 brine production wells located on both sides of the Dolores River and 

construction of a second brine injection well. This alternative would achieve the goal of 90-

percent reduction in salt loading to the Dolores River. Funding constraints have eliminated any 

further consideration of this alternative. 

The proposed plan addressed in this document is to operate the presently constructed test 

facilities on a long term basis. The existing test facilities consists of a brine production well field 

and associated collecting pipelines and access roads located on the east side to the Dolores River, 

a surface treatment facility, a 3.7 mile long connecting pipeline, one brine deep well injection 

facility, 1.2 miles of access road to the injection facility and about 1.2 miles of 69-kilovolt (kV) 

power line to the injection facility. This Environmental Assessment evaluates the environmental 

effects of operating and maintaining the presently constructed facility as a contribution to the 

Colorado River Basin Salinity Control Project. 

2 

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Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

In,jection Well No. 1 and Derrick 

July 1990 IBureau of Reclamation Photo by 'fom Wamsley 

3 

Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Six Freshwater Storage Tanks-- July 1990 official file photo 

4 

Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Interior of Brine Injection Facility 

Three PZ-11 Triplex Positive Displacement Pumps in the Background 

July 1990 Bureau of Reclamation photo by Tom Wamsley 

5 

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Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Chapter 1 -Purpose of and Need for Action 

The Unit was authorized for construction by the Colorado River Basin Salinity Control Act of 

1974 (PL93-320, amended; PL98-569) as part of a basin wide program to improve water quality 

in the Colorado River for the benefit of water users in the United States and Mexico. Title II of 

the Act is directed toward salinity control in the United States above Imperial Dam. It authorized 

construction of this Unit and three other projects. The goal of these projects is to reduce salt 

concentrations to threshold levels adopted in 197 5 by member states comprising the Colorado 

River Basin Salinity Control Forum (Forum). It is estimated that more than a million tons of salt 

per year will need to be removed from the Colorado River system by the year 2010 to meet the 

Forum's established criteria. 

Chapter 2 - Alternatives 

Proposed Action 

The proposed action consists of operating the presently constructed deep well injection test 

facility as the Unit's permanent contribution to the salinity control effort. While the proposed 

action does not achieve the Unit's original goal of eliminating 90 percent of the salt entering the 

Dolores River from the Unit area, it does provide a significant reduction in the total salt loading 

to the Colorado River, without expending additional construction dollars. The Unit, as presently 

constructed, will achieve a 50- to 71-percent reduction in salt loading to the river from the Unit 

area 

Facilities to be operated and maintained include the injection well and facilities located 

approximately 1.2 miles south from Colorado Highway 90, a 20-foot-wide access road to the 

injection well, a brine production well field located on the east side of the Dolores River, a 

surface treatment facility located adjacent to the brine production field, a 3.7-mile buried pipeline 

from the brine well field to the injection well, and a 69-kV power line from Highway 90 to the 

injection well. 

No Action Alternative 

The No Action Alternative would allow the continued inflow of approximately 205,000 tons of 

salt annually to the Dolores River. This alternative would require the abandonment of existing 

facilities. Abandoning the Unit would be costly, as well. 

6 
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Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Chapter 3 -Affected Environment and Environmental Consequences 

Introduction 

Construction of the Unit is now complete and all environmental effects resulting from that 

construction have occurred. The 1979 FES addressed impacts to the environment which would 

result from construction of the Unit's brine well field. The 1986 Final Environmental 

Assessment, Deep Well Injection Testing Program, described the environmental effects ofthe 

construction and test operation of the Unit facilities and resulted in a Finding ofNo Significant 

Impact (FONSI). There are three possible impacts that have not been addressed in either of the 

NEP A documents prepared for this project. These are: 

(1) 

(2) 

(3) 

Deep well injection testing has quantified the amount of brine fluid the facility is capable 

of injecting and has revealed the necessity of using some freshwater during the injection 

process. Therefore, the Unit's effect on water resources and associated impacts to 

vegetation, fish and wildlife will be evaluated in this document. 

Test operations ofthe Unit's facilities have provided additional data concerning seismic 

occurrences resulting from operation. Therefore, the Unit's effect on seismicity and 

tectonics in the area will be evaluated here. 

Threatened and Endangered Species lists have changed since the 1986 EA. These 

changes have resulted in a need to prepare a Biological Assessment on how permanent 

operations of the Unit might affect the presently threatened or endangered species. The 

Biological Assessment and Biological Opinion are attached to this document as 

Appendices Band C, respectively. 

Surface Water Resources 

Affected Environment 

The Dolores River, West Paradox Creek, and the ephemeral East Paradox Creek are the 

primary streams in the Unit area. Several small intermittent streams flow into these larger water 

courses during spring snow melts or during thunderstorm activity. The SDPR, Chapter III, 

describes in detail the flow characteristics of the Dolores River and West Paradox Creek. 

7 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Environmental Consequences 

Operation of the Unit would inject up to 400 gallons per minute (gpm) or 0.89 cfs of 

fluid into the underlying geologic formations. The fluid would consist of (I) a mixture of 70 

percent brine, which would be pumped from the brine production well field, and (2) 30 percent 

fresh water obtained from the Dolores River. Due to the mixing requirement, only I 0 brine 

production wells located on the east side of the Dolores River would be pumped at a sustained 

rate of about 280 gallons per minute (0.62 cfs). Operation of the Unit with a plant factor of 

80 percent would result in an annual depletion to the Dolores River of about 516 acre-feet. 

Operation of the Unit would not affect East or West Paradox Creeks. 

McPhee Reservoir, a feature of the Dolores Project, was completed in 1985 and is located 

upstream from the Unit on the main stem of the Dolores River near the town of Dolores, 

Colorado. Operating criteria for the Reservoir provides for year-round releases downstream to 

the Dolores River that will eliminate the chronic summer low/no flow conditions which 

historically occurred during dry years. In 1996, Reclamation acquired additional water for 

release from McPhee Reservoir downstream to the Dolores River. These releases will more than 

offset the small depletion to the river caused by operation of the Unit. 

Reclamation has water rights from the Dolores River totaling 4.95 cfs for the purpose of salinity 

control. Reclamation also has an Augmentation Plan, approved by the District Court for use in 

Water Divisions 4 and 7. This Plan allows for out of priority pumping of the brine production 

wells should a call be placed on the Dolores River. 

Groundwater Resources 

Affected Environment 

An aquifer of brine appears to underlie the entire Paradox Valley at varying depths. The 

brine groundwater is very close to the surface along the Dolores River and is in contact with the 

bottom and sides of the river channel for about 1.5 miles, beginning in the middle of the valley 

and extending downstream to near the exit of the valley. The depth to the top of the brine 

appears to increase as you move upstream and to the west. In a well about a mile west of the 

river, the depth to brine has been measured at over 100 feet. To the east of the river. the brine 

remains near the surface. It is impractical to directly measure the brine inflow, because it comes 

from many small springs and seeps. Reclamation estimates that the brine inflow varies from 

about 0.2 to 2.1 cfs, and average about 0.8 cfs. This inflow exhibits a certain degree of annual 

and seasonal fluctuation. 

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Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

A layer of comparatively fresh water overlies this brine groundwater in the Paradox Valley. In 

west Paradox Valley, the top of the fresh water lies from 1 0 to 40 feet below the surface, 

depending upon location. The fresh water is pumped from wells for irrigation. The closest 

irrigation well is about 1 mile west of the river. The layer of fresh water is at least 1 00 feet thick 

about a mile west of the river and gradually becomes thinner as it approaches the river. The fresh 

water layer is very limited on the east side of the river. The combination of fresh and brine 

groundwater contributes between 1.5 and 4 cfs to the Dolores River's flow in the Paradox 

Valley. 

Environmental Consequences 

Pumping brine from the brine production well field would lower the elevation of the 

interface between the brine and upper fresh water aquifers. Since the brine pumped from the 

aquifer will be replaced by fresh water from the river, the elevation of the groundwater table will 

remain approximately the same. Some localized lowering of the water table will occur in the 

immediate vicinity of the brine wells. But, pumping the brine production wells will not affect 

wells completed in the fresh water aquifer. 

Water Quality 

Affected Environment 

Surface Water Quality.-The SDPR, Chapter III, describes in detail the changes that 

occur in the water quality of the Dolores River as it flows through the Paradox Valley. Water 

quality of the Dolores River is monitored at the United States Geological Survey (USGS) 

gauging station at Bedrock as the river enters the Valley and at the USGS gauging station near 

Bedrock as the river exits the valley. IDS concentration ranges from 110 to 2,000 mg/1 as the 

river enters the valley and from 120 to 20,850 mg/1 as. the river exits the valley. 

Groundwater Quality.-Water quality of groundwater in the Unit area is discussed in 

the SDPR, Chapter III. Groundwater in the Unit area consists of a brine aquifer which underlies 

almost the entire Paradox Valley and a fresh water aquifer which overlies the brine primarily in 

west Paradox Valley. Samples of the brine groundwater have varied in salinity from about 

117,500 mg/1 to near 300,000 mg/1. The brine produced from the Unit's production wells have a 

IDS concentration of over 250,000 mg/1. Variations in quality probably result from different 

degrees of mixing with fresher groundwater in the area. About 94 percent of the IDS are sodium 

and chloride. The inflow of brine groundwater to the Dolores River accounts for essentially all 

of the salt picked up through the Paradox Valley. 

9 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

As part of the program to complete the test injection well, water samples were obtained from the 

injection zone. The lower formations (Precambrian, Ignacio, and McCracken) contain no water. 

Samples obtained from the Leadville Formation were sodium-calcium-chlorine brine with a total 

dissolved solids concentration of approximately 218,000 milligrams per liter. 

Environmental Consequences 

Surface Water Quality.-The proposed action would improve the quality of water in the 

Dolores River by intercepting and disposing of brine groundwater before it enters the river. The 

proposed action would prevent an estimated 100,000 to 145,000 tons of salt from entering the 

Dolores River annually, and significantly decrease the average annual flow-weighted salinity of 

the river. The largest reductions would occur in concentrations of sodium and chloride, with 

relatively small reductions in sulfate, potassium, magnesium, and calcium. Overall, the water 

quality of the river as it leaves the valley would be significantly improved over existing 

conditions. It would, however, still exhibit an increase in salinity, because the project would not 

prevent all of the salts from entering the river as it crosses the valley. 

Groundwater Quality.-The quality of the groundwater in the Unit area would not 

change. The injection ofParadox Valley brine, averaging approximately 251,000 mg/L TDS into 

the Leadville Formation, would slightly increase the salinity of the in-situ water located some 

15,000 feet below the surface. The depth and isolation of this formation render the migration of 

the brine into useable aquifers virtually impossible. 

Vegetation 

Affected Environment 

Vegetation communities in Paradox Valley vary according to elevation, precipitation, 

soil type, land use, and other factors. Vegetation composition and density in the general vicinity 

of the Unit vary according to the seasonal availability and quality of water and soil type. 

Vegetation communities include riparian associations along the Dolores River and West Paradox 

Creek; irrigated agriculture in the western portion of Paradox Valley; sagebrush and semi desert 

shrub lands of greasewood, seablite, and winterfat-snakeweed in the eastern portion of the valley; 

and pinyon-juniper woodland at the higher elevations on the sides of the valley. 

The riparian vegetation is dominated by tamarisk, which varies from sparse along the east side of 

the river to dense groves up to l 00 yards wide supported by the meandering of the lower portion 

of West Paradox Creek. Grasses, with rushes and sedges in marshy areas, form the understory on 

the west bank of the Dolores River, while no significant understory is found on the east bank. 

10 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Stands of cottonwood trees with a tall shrub understory of New Mexico forestiera and a lower 

understory of grasses are scattered along both sides of the river upstream from the brine inflow 

area. In the brine production well field (area of brine groundwater) and downstream along the 

river, the riparian vegetation consists almost entirely of sparse tamarisk with little to no 

understory. 

Irrigated land occupies much of the valley floor west of the river, with major crops consisting of 

alfalfa, grains, and pasture. Sagebrush communities occupy most of valley east of the river. The 

understory is sparse and consists of perennial grasses and mixed annual forbs. In many areas, 

poor soil conditions, sometimes exacerbated by overgrazing, have reduced the understory to 

primarily cheatgrass. 

The greasewood community is found in the vicinity of the brine well field, along East Paradox 

Creek, and in other intermittent drainage and arroyos in eastern Paradox Valley and Dry Creek 

Basin. The dominant plant is black greasewood which may be found in association with other 

species such as seablite and scattered big sagebrush. In most instances, the understory is very 

sparse or totally absent. Seablite is the dominant plant in areas near the well field where 

greasewood is not found. In general, little or no understory of grasses is present in these areas, 

which are characterized by salt -encrusted ground. 

Pinyon-juniper woodland is found on the slopes of Paradox Valley and on the surrounding 

mesas. Pinyon pine and Utah juniper dominate, although Rocky Mountain and common juniper 

are also present. The understory consists of woody shrubs, such as mountain snowberry, 

antelope bitterbrush, mountain mahogany, and serviceberry. Also found in this community are 

big sagebrush, rabbitbrush, prickly pear cactus, and various forbs and grasses. 

Environmental Consequences 

Continued, permanent operation of the facility would not result in any additional. adverse 

impacts to vegetation other than those which have already occurred. All areas disturbed during 

construction have been regraded back to contour and reseeded. 

McPhee Reservoir, a feature of the Dolores Project, was completed in 1985 and is located 

upstream from the Unit on the main stem of the Dolores River near the town of Dolores. 

Colorado. Operating criteria for the reservoir provides for year-round releases downstream to the 

Dolores River that will eliminate the chronic summer low/no flow conditions which historically 

occurred during dry years. In 1996, Reclamation acquired additional water for release from 

McPhee Reservoir downstream to the Dolores River. These releases will more than offset the 

11 
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Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

small depletion to the river caused by operation of the Unit and will benefit the riparian 

vegetation more than historic conditions. 

Seventy percent of the depletion to the river resulting from project operation will be brine with a 

TDS concentration of over 250,000 mg/1. Lowering the brine water table in the brine production 

well field area and the resulting improved water quality in the Dolores River may allow the 

growth of more riparian vegetation in the well field area and provide benefits to the riparian areas 

downstream from the Unit. 

Wetlands and Riparian Habitats 

Affected Environment 

Riparian habitat in the vicinity of the Unit is sparse along most of the Dolores River in 

and below the area of brine inflow and consists mainly of scattered tamarisk. Superior riparian 

habitat above the brine inflow area consists of cottonwood stands scattered along both sides of 

the river upstream from the confluence with West Paradox Creek. The stands are associated with 

a tall shrub understory of New Mexico forestiera and a lower understory of grasses. The most 

significant wetland habitat near the project is located across the river from the brine well field on 

the west bank of the Dolores River. This wetland, which would be classified as a scrub-shrub 

wetland (Cowardin et.al., 1979), is dominated by tamarisk in fairly large patches and situated 

along the river and the lower portions of West Paradox Creek. This wetland is supported by 

saturated soils resulting from the meandering and overflows of West Paradox Creek caused by 

spring snow melt, summer storm runoff, return flows from up-slope irrigated lands, and possibly 

percolating groundwater flowing from West Paradox Valley. There are approximately 60 acres 

of scattered riparian vegetation along the Dolores River below the Unit area to the confluence 

with the San Miguel River. 

Environmental Consequences 

All disturbances associated with construction of the Unit have ceased and long-term 

operation of the Unit would not result in additional disruption to the existing habitat. All project 

major facilities and structures are located on the east side of the river. The wetland located along 

the west bank of the Dolores River is supported by West Paradox Creek and possibly surfacing 

groundwater flowing from Paradox Valley. Brine well pumping from groundwater on the east 

side of the river would not affect this wetland. 

McPhee Reservoir, a feature of the Dolores Project, was completed in 1985 and is located 

upstream from the Unit on the main stem of the Dolores River near the town of Dolores, 

12 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Colorado. Operating criteria for the Reservoir provides for year-round releases downstream to 

the Dolores River that will eliminate the chronic summer low/no flow conditions which 

historically occurred during dry years. These releases will more than offset the small depletion 

to the river caused by operation of the Unit and will benefit riparian vegetation more than historic 

conditions. 

Seventy percent of the depletion to the river resulting from project operation will be brine with a 

TDS concentration of over 250,000 mg/1. Lowering the brine water table in the brine production 

well field area and the resulting improved water quality in the Dolores River may allow the 

growth of more riparian vegetation in the well field area and provide benefits to the riparian areas 

downstream from the Unit. 

Fisheries Resources 

Affected Environment 

Nineteen species of fish representing seven families were captured from the Dolores 

River in fisheries investigations by BIO/WEST Inc., in 1990 and 1991. Of the nineteen species 

collected, 13 were non-native or exotic and 6 were native or endemic to the Colorado River 

system. Non-native species comprised 81 per cent of the total collections. Three non-native 

species, red shiner, sand shiner, and fathead minnow, were the most common of all species 

collected. These species comprised 75 per cent of the total catch. Other non-native species 

collected were white sucker, bluegill, green sunfish, largemouth bass, common, plains killifish, 

black bullhead. channel catfish, brown trout, and rainbow trout (Valdez, 1992). 

Table 111-1. LIST OF NON-NATIVE FISH SPECIES 

Common Name Scientific N arne 

Non-native Species red shiner Cyprinella lutrensis 

sand shiner Notropis stramineus 

fathead minnow Pimephales promelas 

white sucker Catostomus commersoni 

bluegill Lepomis macrochirus 

green sunfish Lepomis cyanellus 

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Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

largemouth bass Micropterus salmoides 

common carp Cyprinus carpio 

plains killifish Fundulus zebrinus 

black bullhead Ameiurus melas 

channel catfish Ictalurus punctatus 

brown trout Salmo trutta 

rainbow trout Oncorhynchus mykiss 

Native species comprised the remaining 19 per cent of the total catch. Of the 6 native species 

sampled, flannelmouth sucker was the most abundant and comprised 9 per cent of the total catch 

of native species. Other native species sampled in order of abundance included roundtail chub, 

bluehead sucker, speckled dace, mottled sculpin, and Colorado squawfish. The composition of 

native species in the Dolores River is four times higher than in the adjacent Colorado River. 

This trend is indicative of a relatively good native fish fauna. No significant changes in species 

composition were evident when compared to similar surveys conducted on the Dolores River in 

1981, indicating that the fish community had remained stable over the last ten years (Valdez, 

1992). 

Table 111-2. LIST OF NATIVE FISH SPECIES 

Common Name Scientific Name 

Native Species flannelmouth sucker Catostomus latipinnis 

roundtail chub Gila robusta 

bluehead sucker Catostomus discobolus 

speckled dace Rhinichthys osculus 

mottled sculpin Cottus bairdi 

Colorado squawfish Ptychocheilus lucius 

The four Colorado squawfish captured in the lower 2 km of the Dolores River during the 1991 

study may constitute the first record of this species since 1965. Although the species was 

14 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

reported in the Dolores River in the 1950's and 1960's, spills of uranium mill wastes in the lower 

San Miguel river in mid-1960 killed most of the fish in the lower 60 miles of the river (Valdez, 

1992). 

Environmental Consequences 

Operation of the Unit as presently constructed would result in annual water depletions of 

the Dolores River of 516 acre-feet. This represents a significant reduction in depletions from 

plans proposed in 1977 and 1989. Improvements in water quality which will be achieved as a 

result of the Unit's long-term operation will benefit the aquatic and fishery resources of the 

Dolores River. 

McPhee Reservoir, a feature of the Dolores Project, was completed in 1985 and is located 

upstream from the Unit on the main stem of the Dolores River near the town of Dolores, 

Colorado. Operating criteria for the Reservoir provides for year-round releases downstream to 

the Dolores River that will eliminate the chronic summer low/no flow conditions which 

historically occurred during dry years. In 1996, Reclamation acquired additional water for 

release from McPhee Reservoir downstream to the Dolores River. These release will more than 

offset the small depletion to the river caused by operation of the Unit and will provide benefits to 

the endangered and other fish species in the Dolores River. 

Wildlife 

Affected Environment 

Mule deer, elk, black bear, and mountain lion are the major big game species found near 

Paradox Valley. Approximately 3 00 mule deer are estimated to winter in the Paradox Valley. 

While few deer are harvested in the Unit area, approximately 100 to 300 are harvested annually 

in the eastern portions of Dry Creek and the La Sal Mountains. 

Although their numbers have been increasing, elk normally do not use Paradox Valley as 

extensively as mule deer. The valley is potential annual winter elk range, and it serves as winter 

range during high snowfall years. A few elk occasionally visit the valley during the summer. 

Annual harvest is minimal since elk are usually in their summer ranges at higher elevations 

during the hunting season. 

Black bear are occasional but rare residents in the general project area, since they normally are 

found at higher elevations on the east side of the La Sal Mountains in Utah. They are 

15 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

occasionally sighted by the landowners at the west end of Paradox Valley. 

An estimated 6 to I 0 mountain lions were in the Unit area in 1975. The western portion of the 

valley appears to be the best mountain lion habitat. Hunting for mountain lion has been allowed 

since 1965. 

The only small game animal found in the Unit area is the desert cottontail, which occurs 

throughout the area and is especially abundant in the sagebrush habitat to the east and in the 

riparian habitat along the Dolores River. Although no numbers are available, populations 

undergo moderate hunting pressure. 

The beaver, black-tailedjackrabbit, coyote, muskrat, ringtail, martin, long-tailed weasel, badger, 

gray fox, and striped and spotted skunks are the principal furbearers that inhabit the overall area. 

Beaver and muskrat are by far the most common; they are found primarily along area streams 

and also along irrigation ditches and drainage systems in western Paradox Valley. The coyote, 

common throughout the Unit area, tends to concentrate at lower elevations during the winter. 

The black-tailedjackrabbit is widely distributed in grasslands, croplands, and sagebrush flats. 

Although trapping pressure is light to nonexistent, beaver and muskrat, which are trapped 

commercially to prevent damage to irrigation ditches, constitute the greatest portion of the annual 

harvest. The coyote has also become a valuable fur resource in the valley due to recent 

population increases and increased hunting and trapping pressure. 

Although the ringtail is rarely seen because of its strictly nocturnal and secretive nature, it is 

quite common in the rocky areas along the lower Dolores and San Miguel Rivers. The martin is 

rare and likely only found in the forests west of Paradox Valley. The long-tailed weasel 

population is considered to be small due to the valley's low altitude which is not considered good 

habitat for this species. Although badgers are not common, they do occur in most habitats in the 

valley. The gray fox is quite common, mainly along stream bottoms and in other riparian areas, 

particularly West Paradox Creek. Striped skunks are often seen in lower-elevation stream 

valleys and farmlands closely associated with man. Spotted skunks are rare, preferring rocky 

habitats at lower elevations. 

Other less common furbearers found in Paradox Valley are the bobcat, red fox, raccoon, and 

porcupine. Bobcats are uncommon but occur in canyons along the Dolores River and on mesas 

southwest of the valley. The red fox is rare but may occur at the confluence of the Dolores River 

and West Paradox Creek. Raccoons are generally limited to specific areas along the Dolores 

River, West Paradox Creek, and western valley agricultural areas. Porcupines are not common in 

the Unit area but are more common in the pinyon-juniper habitats on the boundaries of Paradox 

Valley. 

16 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Small mammals or rodents that provide an important prey base for predators in the area are the 

deer mouse, western harvest mouse, pinyon mouse, brush mouse, valley pocket gopher, whitethroated woodrat, Mexican woodrat, least chipmunk, Colorado chipmunk, Ord's kangaroo rat, 

rock squirrel, Gunnison's prairie dog, and white-tailed antelope ground squirrel. The deer mouse 

is the most abundant and the white-tailed ground squirrel is the least abundant prey species. 

Gunnison's prairie dog is not common in the Unit area. 

The Unit area provides habitat for at least 13 species of raptors. The golden eagle, northern 

harrier, Cooper's hawk, sharp-shinned hawk, red-tailed hawk, American kestrel, prairie falcon, 

goshawk, and great homed owl are year-round residents. Northern harriers and American kestrel 

populations may increase dramatically in the breeding season. The turkey vulture, bald eagle, 

ferruginous hawk, and rough-legged hawk are seasonal residents. Peregrine falcons nest in 

Paradox Valley near the Unit, with at least one confirmed nest active in 1995. 

Golden eagles nest in the Dolores River Canyon and along Rock Creek, a tributary to the river 

downstream from Paradox Valley. Preferred hunting areas are normally open and include the 

whole valley. Cooper's hawk, sharp-shinned hawks and goshawk are not common but are found 

in riparian and pinyon-juniper habitats. Northern harrier and red-tailed hawks generally prefer 

open areas. 

The American kestrel, the most common raptor in the Unit area, can be found in croplands, 

desert shrub, pinyon-juniper, and riparian habitats and is frequently seen on fences and power 

lines near roads. Prairie falcons are rare in the area, but, an active eyrie was found on the north 

rim of eastern Paradox Valley during the spring of 1976. Rough-legged hawks are winter 

residents only and prefer cropland, grassland, and low desert shrub habitats with prominent 

perching sites. The great horned owl is fairly common in riparian and pinyon-juniper habitats 

that have suitable nest and roost trees. Turkey vultures are common during the late spring and 

surmner but are not known to nest in the area. 

Mourning dove. band-tailed pigeon, and ring-necked pheasant are the primary game birds of the 

Paradox Valley. The ring-necked pheasant is a year-round resident, while doves and pigeons 

inhabit the area from spring through fall. Doves receive moderate hunting pressure, feed in 

agricultural and semidesert shrub lands, and nest in riparian and pinyon-juniper habitats. Bandtailed pigeons are not common, seeming to prefer higher elevations north of the valley. Ringnecked pheasants are common in agricultural and riparian habitats; hunting pressure is low since 

populations are found mainly on private ground. lin 1988, in cooperation with the Colorado 

Division of Wildlife (CDOW), Reclamation sponsored the release of233 chukars at four 

locations in Paradox Valley to stabilize existing populations, provide a prey base for the 

17 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

endangered peregrine falcon, and increase recreational hunting opportunities. 

The Dolores River serves as an important feeding and resting area for numerous species of 

waterfowl and shorebirds. Although most species found here vary widely from season to season, 

mallards are the most common species annually. Gadwall, Canada goose, pintail, green-winged 

teal, redhead, common merganser, and American coot are species that use the river and stock 

tanks. Hunting pressure is considered moderate in the fall and winter. 

The shorebirds identified in the Unit area were the killdeer, common snipe, and spotted 

sandpiper. Other species of shorebirds are likely to frequent the area, especially the wetland area 

along West Paradox Creek during spring and fall migrations. 

Of approximately !50 species of nongame birds that could frequent the Unit area, 92 species 

were identified during the inventories completed in 1976. Many of the nongame birds identified 

are typical of southwestern Colorado and include whippoorwill, ashthroated flycatcher, bank 

swallow, plain titmouse, common bushtit. Bewick's wren, rock wren, gray catbird, yellowthroat, 

blue grosbeak, Lazuli bunting, brown-capped rosy finch, gray-crowned rosy finch, lark sparrow, 

sage sparrow, and Brewer's sparrow. 

The floodplain (riparian) and wetland habitats along the Dolores River, together with that of 

West Paradox Creek, probably constitute the most important of the vegetation habitat 

communities in the Unit area. In descending order of importance, the other communities include: 

pinyon-juniper woodland, agricultural land, sagebrush, native grassland, and monocultures of 

desert shrub habitats of seablite, winterfat-snakeweed, and greasewood. The habitat value of the 

desert shrub communities for wildlife would be slightly increased if communities were mixed. 

Streams, springs, wetlands, and stock ponds in the Unit area support such amphibians as the redspotted, Rocky Mountain, and Hammond's spade-foot toads, and western leopard frog. Reptiles 

inhabiting the unit right-of-way near the Dolores River include the wandering garter snake and 

the short-homed lizard. Sagebrush and pinyon-juniper habitats contain such species as northern 

sagebrush, northern plateau, and short-homed lizards; plateau whiptail; Great Basin gopher 

snake; and midget faded rattlesnake. Semidesert shrub lands and rocky outcrops provide 

habitat for short-homed, northern sagebrush, northern plateau, and northern tree lizards; Great 

Basin gopher and wandering garter snakes; western yellow-bellied racer; and midget faded 

rattlesnake. 

18 
Environmental Consequences 

Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Construction of the Unit is now complete and all environmental effects resulting from 

that construction have occurred. Vegetation loss has been mitigated with reseeding efforts in all 

areas except where permanent facilities have been constructed. Continued permanent operation 

of the facility would not result in any additional adverse impacts to existing wildlife species 

except for impacts from water depletions to the Dolores and Colorado Rivers of approximately 

516 acre-feet/year. Wildlife may experience permanent, limited disruption caused by human 

activity as a result of operating the Unit on a long-term basis. 

McPhee Reservoir, a feature of the Dolores Project, was completed in 1985 and is located 

upstream from the Unit on the main stem of the Dolores River near the town of Dolores, 

Colorado. Operating criteria for the Reservoir provides for year-round releases downstream to 

the Dolores River that will eliminate the chronic summer low/no flow conditions which 

historically occurred during dry years. In 1996, Reclamation acquired additional water for 

release from McPhee Reservoir downstream to the Dolores River. These releases will more than 

offset the small depletion to the river caused by operation of the Unit. 

Riparian vegetation in the 7 miles downstream along the Dolores River to the confluence with 

the San Miguel River would slowly improve due to a decrease in overall salinity resulting from 

operation of the Unit. Waterfowl and shorebird habitat would be enhanced by the decrease of 

salinity in the Dolores River and resulting improvement of riparian and aquatic communities 

downstream of the brine well field. Amphibian populations are expected to increase with the 

replacement of existing brine pools and salt deposits along the river with fresh water during 

spring and early summer high flows. 

Threatened and Endangered Species 

Reclamation prepared a Biological Assessment to address potential impacts of long term 

operation of the Unit on threatened and endangered species. The Biological Assessment and the 

Biological Opinion prepared by the Fish and Wildlife Service are included in Appendices B and 

C, respectively. The following table summarizes Reclamation's assessment of the impacts of 

operation of the Unit. 

19 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

SUMMARY OF POTENTIAL IMP ACTS 

SPECIES POTENTIAL RECOMMENDED 

PROJECT IMPACTS MITIGATION MEASURES 

American No impacts; species habitat not affected No species-specific mitigation measures 

peregrine falcon by project recommended 

Bald eagle No impacts; minor depletions will not No species-specific mitigation measures 

affect existing habitat. recommended. Water quality improvements 

will benefit species 

Black-footed ferret No impacts; species habitat not affected No species-specific mitigation measures 

by project recommended 

Bonytail chub No impacts; minor depletions will not No species-specific mitigation measures 

affect existing habitat recommended. Water quality improvement 

and upstream flow releases will benefit species 

Colorado No impacts; minor depletions will not No species-specific mitigation recommended. 

squawfish affect existing habitat Water quality improvement and upstream flow 

releases will benefit species 

Humpback chub No impacts; minor depletions will not No species-specific mitigation measures 

affect existing habitat recommended. Water quality improvements 

and upstream flow releases will benefit species 

Mexican spotted No impacts; affected environment does No species-specific mitigation measures 

owl not provide suitable habitat for species recommended 

Razorback sucker No impacts; minor depletions will not No species-specific mitigation measures 

affect existing habitat recommended. Water quality improvement 

and upstream flow releases will benefit species 

Southwest river No impacts; minor depletions will not No species-specific mitigation measures 

otter affect existing habitat recommended. Water quality improvements 

and upstream flow releases will benefit species 

Southwestern No impacts; minor depletions will not No species-specific mitigation measures 

willow flycatcher affect existing environment recommended. Water quality improvements 

and upstream flow releases in addition to 

control of overgrazing and exotic vegetation 

would benefit species 

The Service did not agree with Reclamation's finding of no significant impacts to any threatened or 

endangered species. The Service concluded that operation of the Unit "is likely to jeopardize the 

continued existence of the Colorado squawfish, humpback chub, bonytail, and razorback sucker and 

20 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

result in the destruction or adverse modification of their critical habitat." The Service determined that 

the depletion resulting from the Unit's operation would reduce the physical habitat available to the 

endangered fish, contribute to an increase in nonnative fish, and increase the concentrations of heavy 

metal, selenium, salts, PHA's, pesticides, and other contaminants in the Colorado River. However, 

the Service concluded that because the Unit's average annual depletion of 516 AF is below the 

current sufficient progress threshold of 1,500 AF, continued participation by Reclamation in the 

Colorado River Recovery Implementation Program would allow operation of the Unit and avoid the 

likelihood of jeopardy to the endangered fishes and avoid destruction or adverse modification of 

critical habitat. The Service concluded that these actions would serve as the reasonable and prudent 

alternative. 

Reclamation concurs with the Service's determination of the reasonable and prudent alternative. 

However, Reclamation continues to disagree with the conclusion by the Service that operation of the 

Unit would deteriorate water quality in the Colorado River. The Unit's operation will prevent 

approximately 128,000 tons of salt from entering the Colorado River system annually resulting in 

improved water quality in the River. 

Seismicity and Tectonics 

Affected Environment 

The seismotectonic setting of the area is discussed in general terms in chapter II of the 

SDPR. The observations regarding seismicity in the area can be summarized as follows: 

• The Unit is within a zone exhibiting a low rate of naturally occurring seismicity, 

• no events with magnitudes greater than 0 have been detected within 5 km of the well in about 5 

years of monitoring prior to injection. 

• Pre-injection seismicity is shown on figure 1; 

• the closest significant seismicity appears to be associated with faults bounding the southwest 

side of the Uncompahgre Plateau ( -100 km east of the Unit near Ridgway, Colorado). 

• The possible occurrence of earthquakes as a consequence of deep well injection at this site was 

considered in the Deep Well Injection Testing Program Final Environmental Assessment. 

Since the submission of these documents, Reclamation has conducted several test injection sequences 

21 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

with all but one of the sequences resulting in earthquakes of sufficient size to be detected by the 14-

station Paradox Valley Seismic Network (PVSN). An oblique view of the well bore and injection 

related seismicity is shown as figure 2. As of the end of March 1995, more than 750 events had been 

located near the well. All of these events appear to be related (spatially and temporally) to the 

injection process. The duration of injection, wellhead pressure, injection rate, and fluid composition 

have varied for each injection period, and the level of seismicity has been generally correlated with 

these injection parameters. The relationship between injection parameters and earthquake occurrence 

is shown in figure 3. 

Earthquake Location Procedure.-In an area with a low level of naturally occurring 

background seismicity (such as the Paradox Valley area), the association of abundant seismicity with 

fluid injection and subsequent migration of injectate appears clear. The ability to define where the 

fluid is flowing in the subsurface is related to the ability to define where the earthquakes are located 

in three dimensions. The process of estimating an earthquake's location involves a number of 

unknowns: the location of the hypocenter (x,y, and z), the origin time ofthe event, the ability to 

correctly interpret and read the seismograms for seismic phase arrival times, the distribution and 

quality of seismograph stations, and the velocity structure of the region for both compressional (P) 

and shear (S) waves. A considerable amount of effort has gone into estimating these parameters for 

the Paradox site. Several factors provide positive constraints on several of the unknowns at this site. 

A partial suite of well logs acquired during construction provide velocity information along the well 

bore. It is reasonable to infer that the first set of earthquakes occurring within the first few hours of 

injection must have occurred near the well. This fact provides a "known" location for some of the 

events. This enables future events to be identified as injection induced or naturally occurring by their 

relative location to the well. Negative factors at this site include an obviously three-dimensional 

character to the velocity structure, rather broad spacing of the seismograph stations, and the lack of 

more than one three-component station. To provide the best possible earthquake locations, a 

simultaneous hypocenter-velocity inversion was performed. Arrival time data collected during 

injection sequence seven (September 1994-March 1995) were used. Only earthquakes with 

magnitudes greater or equal to 0.7 were used in the analysis (to maximize signal-to-noise ratio). A 

total of 382 events from injection sequence seven were included in the analysis. All22 ofthe events 

that occurred during the first injection sequence (July 1991) were included in the inversion as well. 

The locations of these 22 events were fixed at the center of the perforated zone of the borehole which 

was computed from the deviation survey. These events with fixed locations were included to 

minimize the trade-off between hypocenter, velocities, and station corrections that occur in joint 

velocity-hypocenter inversions. To provide additional ray coverage for the velocity inversion, data 

from other earthquakes away from the well and some explosions near Uravan were included in the 

procedure. 

Earthquake Location Resu/ts.-Figures 2 and 4 display the results of the three22 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

dimensional velocity inversion procedure for 630 selected events associated with injection. Also 

displayed on these figures is a digital elevation model oftopography in the Paradox area, the deviated 

well bore, as well as a subsurface rendering of the top ofthe Leadville Formation (the target horizon) 

and faults within the formation that were previously inferred from seismic reflection data. Figure 2 is 

an oblique view approximately parallel to the strike of the inferred faults and shows nearly all of the 

hypocenters. The orientation of figure 4 displays the hypocenters that lie above the top of the 

Leadville Formation. Figure 4 clearly shows that a large number of earthquakes are occurring above 

the Leadville Formation. Uncertainties in hypocentral depths are judged to be approximately 300 

meters. The evolution of earthquake focal depths (and by inference migration of fluid) with time is 

illustrated on figure 3. During the first three injection sequences, earthquakes occurred near the well 

bore and in a depth interval within or below the Leadville Formation. Beginning with the fourth 

injection sequence and continuing through the end of the seventh test sequence, the earthquakes 

migrated west-northwest and shallowed slightly. The minimum depth of events appears to be -3 km. 

The trend of the events in plan view is subparallel to the strike of the Paradox Valley and associated 

structural features. 

A procedure that was previously developed for mapping fractured planes-produced by high pressure 

fluid injection for geothermal development-was applied to the data set of hypocenters shown on 

figures 2 and 4. This procedure evaluates groups of earthquakes to determine, if the events could lie 

on a common planar surface. Once a surface has been defined, the earthquakes that are associated 

with that surface are removed from the data set and the procedure is repeated to define additional 

planes. Utilizing this methodology, three planes were defined by the earthquake hypocenters. Over 

69 percent of the located hypocenters are contained on the planes (shown on figure 5). The 

orientations and trends of these planes are consistent with the general structural framework of the 

Paradox area (cf. the previously inferred faults shown on figures 2 and 4). An independent evaluation 

of fault plane solutions for larger events produced a trip art representation of least compressive stress 

orientation ("T-axes") that is very consistent with what would be expected for the three planes shown 

on figure 5. 

Figure 6 is a Mohr circle representation of conditions inferred to exist at the bottom of the well (from 

well logs and other information), demonstrating that induced earthquakes are a natural consequence 

of high pressure fluid injection. The hydrostatic case suggests a stable condition prior to injection; 

this is consistent with the very low rate of naturally occurring seismicity observed near the Unit. 

During high pressure injection, the normal stress is reduced in accordance with the effective stress 

law and the circle shifts towards conditions of Coulomb failure. Maximum injection pressures are 

sufficient to produce failure of rocks with intact strengths as great as 140 bars. However, if 

preexisting planes of weakness exist. they will become the loci of fracture events. 

23 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Environmental Consequences 

Seismicity.-No significant tectonic earthquakes have occurred within 50 km of the site. 

To date the largest event associated with injection at the Paradox facility isM 2.6. It cannot be 

precluded that somewhat larger earthquakes may be produced at this site. This is especially true since 

it appears likely that much of the injected fluid is moving along planar surfaces favorably oriented to 

fail in the current tectonic stress regime. 

Fluid Migration.-The occurrence of earthquakes at depths above the "confining layer" 

discussed in earlier studies is contradictory to hypotheses that inferred fluid migration (and hence 

earthquakes) would be confined to the Mississippian Leadville and/or deeper strata. Clearly, fluid 

pressure changes are being manifested at depths shallower than initially proposed. The depth of 

seismicity appears to be inversely correlated with maximum surface injection pressure and injection 

volume. Based upon the observations of injection sequences six and seven, Reclamation considers it 

unlikely that fluid pressure changes would extend above the -3 km depth observed to date for 

injection rates and surface injection pressures at or below those used in test sequences. In order to 

fully document earthquake occurrence (and hence fluid pressure changes) at the site, continuous 

monitoring of the injection parameters and seismicity would be necessary. Accurate determination of 

earthquake focal depths is a critical issue to evaluating and minimizing environmental impacts at this 

site. To that end, an additional three-component station may be necessary to more accurately locate 

earthquake focal depths in the vicinity of the well. 

In summary, deep well injection at the pressures and injection rates to be used at this site would 

produce micro earthquakes. These events would, in general, map out the areas where pore pressures 

are being increased. If earthquakes with magnitudes large enough to cause damage begin to occur, 

injection would be halted and operational parameters reevaluated. If earthquakes with reliable focal 

depths ofless than 2 km occur, injection would be halted and operational parameters re-evaluated. 

The addition of another three-component seismic station near the well may be necessary to improve 

estimation of hypocentrallocations. 

24 

Parodox Valley Unit 

Supplemental Definite Plan Reporl!Environmental Assessment 

Figun; 1. Pre-injec tion earthquake hypocenters (red 3d wireframes) located by the 14 station Parc~ ox Yalky Seismic Network (PVSN) in a 3J projection looking N60°W. Wellbore is the thick 

while line. T he top of the Le ml villc fo rmation near the wellbore is shown in dark blue cul by 

fa ll Its inre rred from se ismi c retkction data. T he shaueu DEM at the top shows Paradox Valley 

<tnd the Dolores River valleys in blue and green with surrounding mesas in red through light yellow. PVSN seismic station:-. are s hown as white tt.:Lra hedra. No earthquakes occurreu with 5 km of 

the wc llbo re duri ng th e 5 years of seismic monitoring prior Lo the first injection test. 

25 

------------- ~ 

Paradox Valley Unit 

$(Jpplemental Definite Plan Report/Environmental AssessmerJt 

Figure 2. Hypocenters (rell 3d wireframes) located above the top of the Leadville formation in a 

:1d projection looking N60W. T he top of the Leadville formation is shown in dark blue and fault::--

cutting the Leadville fo rmation inferred from seismic reflection data are shown in yellow, green, 

anll orange. The shadeJ DEM at the top shows the Paradox valley in blue and green with surrou nding mesas in red through light yellow. Well bore is the thick white line. 

26 

N 

-..J 

Figure 3. The top plot shows the cumulative ftuid inj cctitm volume.: as the.; red curve, the elevati on of ea rthquake hypocenters as yellow circles, and the elevation range of the perfonm·d Lune in th e \\'ell as the blue elevatio n region between 

the magenta lines. Earthquake symbols are sc:1led by magn itut.lc \\ hich ranges from -0.5 to 2.5. The bl)ttom plot sht)WS 

injection rate in yellow and :-> urface injection in red. Thtre are eight tot1 l injectio n sequence :-. and the seven 

injection sequences that produced earthquake::, are lalxkd I1 through 17. Fluid compt)Sition is denoted as follows, FW = 

fresh water, PVB = Paradox Valley brine, WB = 2/3FW+ l /3PVB, ;1n d BW= 1/3FW+2/3PVB. Time is in days since fir:,t date of injection. 

(J)"'tJ t:: Ill Ql 

1D 0 3 

;-::: 

lie::: 

:=. 

iii 

"1l 

il1' 

:::! 

:0 

0 

:S. 

a 

§ 

:to 

(/) 

Ill Ill 

In 

(/) 

3 

Cl) 

::s 

... 

Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

f igure 4. Hypocente rs (red 3d wireframes) located above the top of the Leadville formation in a 

3d projection looking southwest. The top of the Leadville formation is shown in dark blue and 

fau lts cutting the Leadville forma tion inferred from seismic reflection data are shown in yellow, 

green, and orange. The shaded DEM at the top shows th0 Parauox valley and Dolores River valleys in blue and green with -;urrounJing mesas in red through light yellow. Well bore is the thick 

white line. 

28 

Parado)( Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Figure 5. Three subsets of hypocenters (representing 69% of all hypocenters) that show strong 

planctr alignment are .;;hown by connecting all hypocenters in each color coded group with lines 

to (klineate the pLtne orientalion:-- in th ree d imensions. A color shaded OEM is shown at the top 

with the Paradox Valley shown in blue and green <tnd s urrounding mesas in red through white. 

Total diagonal horizontal dimensi un is about 12 km. Plane 1 contains 212 hypoce nters, plane 2 

cont:.~ins 136 hypocente rs, anJ plane 3 contains 85 hypocenters. Vantage point is looking N60°W. 

29 

w 

0 

1000 

500 

,-..... 

rJ:J 

ro 

..0 

'-_' 0 

p 

-500 

-1000 

(Jl 

- (J3 310 bars 

1 = 140 + 0.6 crn 1 = 0.6 crn 

1500 

cr (bars) 

Hydrostatic No fluid pressure 

Injection pressure of 317 bars at the wellhead 

Figure 6. Mohr circle diagram showing inferred state of stress at the bottom of the Paradox Valley injection well (4.9 km depth). 

The two lines indicate failure criteria for Mohr-Coulomb failure; failure occurs if the Mohr's circle intersects (or lies to the left of) 

the failure line. The circle at the right indicates in-situ stresses (estimated from the mechanical properties well logs) in the absence 

of fluid pressure. In the center Mohr's circle, the principle stresses have been shifted to the left by the hydrostatic fluid pressure in accordance with the effective stress law. The leftmost circle indicates stresses at the well bottom during injection (fluid pressure= 

hydrostatic + surface injection pressure). The fact that the circle intersects both lines indicates that pressures at the well bottom 

are not only sufficient to produce faulting on pre-existing faults with zero strength (lower solid failure line), but are sufficient to 

cause faulting even in intact rock with a shear strength of 140 bars (upper dashed failure line). 

"' c 0 

·o 

tJ 

• 

;;; 

" :>J 

• " 0 

s 

3 

" 3 "U 

• u 

£g. " " 

>-

" ' " u 

W

. 

'"' c: 

2. 

-

Paradox Valley Unit 

Supplemental Definite Plan Report!Environmental Assessment 

Chapter 4 - Consultation and Coordination 

Development of the Proposed Plan 

During the salinity investigations for the Paradox Valley Unit, issues and opinions identified by and 

received from individuals, groups, and other agencies were carefully considered. Deep well injection 

of brine was suggested by EPA as an environmentally preferred solution to evaporation in the 

agency's comments on the Unit's Draft Environmental Statement in 1978. Subsequent testing has 

revealed that this preferred solution is viable, and disposal of brine by deep well injection has been 

adopted as part of the project. 

Consultation and Coordination Activities (Environment) 

In September 1994, as testing of the injection well program was being completed and 

future operation plans were being finalized, Reclamation questioned the Service as to the need to 

reinitiate Section 7 consultation on the Unit. The Service responded with a recommendation that 

Section 7 consultation be reinitiated because of changes in the project plan and changes in 

endangered species status since the last consultation. 

Results and Implementation (Environment) 

Reclamation has implemented each ofthe mitigation measures outlined above by the Service in 

the following ways: 

(1) A vegetation monitoring program has been initiated to determine if the removal of 516 

acre-feet annually of brine from the Dolores River alluvium would affect existing 

floodplain vegetation. Infrared aerial photography will be obtained during the growing 

season at specific time intervals. Baseline conditions will be established before brine 

pumping is begun (project operation) as the basis for analyzing photography obtained at 

future dates. The monitoring program is scheduled to be conducted during the first years of 

project operation; continuation or cessation of the monitoring would be contingent upon the 

findings after this initial time period. 

(2) All new power lines constructed for project facilities were designed to eliminate 

electrocution hazards for raptors. 

(3) All disturbed areas (pipeline rights-of-way, injection well, and operation and maintenance 

31 
Paradox Valley Unit 

Supplemental Definite Plan ReportiEnvironmental Assessment 

facilities) were reshaped and revegetated '-'<ith native shrub and grass species to provide food and 

cover for wildlife and increase the diversity of plant species. 

Reclamation funded an "out-of-kind" chukar release mitigation measure recommended by the CDOW 

in Paradox Valley. The goal was to stabilize the existing population, increase the prey base for 

peregrine falcons, and provide increased hunting opportunity for sportsmen. In October 1988, the 

CDOW released 232 chukar at four locations in the valley. 

Consultation and Coordination Activities (Endangered Species) 

On November 12, 1996, the Service commented on the Draft SDPR and EA taking 

exception to Reclamation's determination of "no-effect" on endangered fishes or their critical habitat. 

Due to the agency's "may-effect" opinion, the Service recommended that Reclamation reinitiate 

formal consultation. On December 17, 1996, Reclamation reinitiated consultation based on the 

current Unit plan for long-term operation and maintenance of facilities constructed for the injection 

test. The current plan consists of pumping the brine well field at a rate of about 0.89 cfs and 

disposing of the produced brine in the existing injection well, resulting in an annual depletion to the 

Dolores river of about 516 acre feet. A Biological Assessment was prepared and is included as 

Appendix B. Reclamation concluded that operation ofthe Unit would have "no effect" on 

endangered species. 

On January 17, 1997, Reclamation received a Final Biological Opinion for the Paradox 

Valley Salinity Control Unit from the Service which is included as Appendix C. The Biological 

Opinion (BO) concluded that while the project could jeopardize the continued existence of the 

Colorado squawfish, humpback chub, bonytail, and razorback suckers and their critical habitat, a 

Reasonable and Prudent Alternative (RP A) to ameliorate this threat was available and being 

implemented. The RP A is comprised of: (I) Continued participation in the Recovery Implementation 

Program for Endangered Fish Species in the Upper Colorado River Basin; (2) the commitment by 

Reclamation to operate Upper Colorado River Basin projects under its control to provide instream 

flows for endangered fishes; and, (3) the fact that the depletion is below the sufficient progress 

threshold of 1,500 acre-feet. 

In 1988, Reclamation became a party to the Recovery Implementation Program for Endangered Fish 

Species in the Upper Colorado River Basin. Reclamation agreed to contribute $1.5 million annually 

for 10 years to the recovery program and to operate its units to provide instream flow for endangered 

species as described in the recovery implementation program. In its biological opinion, the Service 

did not request any additional contribution for the maximum 1,448-acre-feet (or 2.0 cfs) depletion 

resulting from operating the Unit. 

32 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Results and Implementation (Endangered Species) 

The Paradox Unit will be operated and maintained as presented in this EA and the SDPR. 

Reclamation will continue to participate in the Colorado River Recovery Implementation Program. 

Indian Trust Assets 

Indian Trust Assets (IT As) are legal interests in property held in trust by the United States for 

Indian tribes or individuals. The Secretary of the Interior is the trustee for the United States on behalf 

oflndian tribes. All Department of the Interior agencies, including Reclamation, share the Secretary's 

duty to act responsibly to protect and maintain IT As reserved by or granted to Indian tribes or Indian 

individuals by treaties, statutes, and executive orders. These rights are sometimes further interpreted 

through court decisions and regulations. Examples of trust assets are lands, minerals, hunting and 

fishing rights, and water rights. In accordance with this policy, Reclamation has determined that the 

Unit area is not near any Indian lands; therefore, Reclamation's activities have no effect on these 

assets. 

Cultural Resources 

Affected Environment 

Both prehistoric and historic archaeological sites are known within the Paradox Valley 

Unit. The Paradox Valley lies at the northeastern periphery of the prehistoric Puebloan (Anasazi) 

culture area and the southeastern periphery of the prehistoric Fremont culture area. Indications are 

that both groups had abandoned the area prior to 1200 AD. Archaic (pre-Puebloan!Fremont) sites are 

also known in the Paradox Valley area, with a strong possibility that Paleo-Indian sites also exist. 

While it cannot be determined when the Utes arrived in the area, they were well established in 

western Colorado by the 1600's and some sites in the Paradox Valley Unit may be associated with the 

Utes. There are also a number of historic Euro-American sites in the Paradox Valley associated with 

early mining and cattle ranching activities. 

Environmental Consequences 

Several laws and executive orders are intended to preserve, protect, and maintain cultural 

resources on public lands. They include, but are not limited to: the Antiquities Act of 1906, the 

National Historic Preservation Act of 1966 (most recently amended in 1992), and the Archaeological 

Resources Protection Act of 1979. Reclamation identified several sites within the acquired lands that 

33 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

are eligible or potentially eligible to the national Register of Historic Places. The brine pipeline and 

injection well, and associated facilities were designed to avoid impacting any archaeological and 

historic properties. Reclamation concluded in consultation with the Colorado State Historic 

Preservation Officer, that no effect on cultural resources would occur as a result of the construction, 

operation, and maintenance ofthe brine pipeline and injection well, and associated facilities. 

Conservation Measures 

In keeping with aforesaid laws on cultural resources, Reclamation will manage cultural 

resource sites within the areas acquired through fee title and easement. Management activities will 

include : I) monitoring of impacts not directly related to operation of the brine injection facility 

(such as erosion and visitation), and 2) evaluating the resources for potential to answer key research 

problems such as determining the age and cultural affiliation of archaeological deposits. 

Environmental Justice 

The project has been analyzed in accordance with Reclamation Policy of August 17, 1994, for 

sensitivity to environmental impacts on minority populations and low-income groups. It has been 

determined that the project would have no adverse impacts on such groups. Environmental impacts 

from construction are complete, and placing the project in operation would improve the quality of 

surface water in the Colorado River Basin downstream of the Unit. Water quality improvement 

directly affects all population groups using the water in a beneficial marmer. Economic loss from 

salinity is reduced for these users which, in tum, provides better economic health for the entire basin. 

This would have a positive effect on all population groups living in the region. 

Environmental Commitment Plan 

Because the project's average annual new depletion of516 acre-feet is below the current 

sufficient progress threshold of 1,500 acre-feet, the Bureau of Reclamation's continued participation 

in the Recovery Implementation Program for Endangered Fish Species in the Upper Colorado River 

Basin will serve as the reasonable and prudent alternative to avoid jeopardy to the Colorado 

squawfish, razorback sucker, humpback chub, and bonytail. It will also serve as the reasonable and 

prudent alternative to avoid destruction or adverse modification of critical habitat caused by the 

project's depletion. Reclamation contributes $1.5 million annually to the Recovery Program. 

All construction associated with the Unit has been completed and the impacts therefrom have been 

mitigated for as required by the Final Environmental Statement and as noted in this final 

Supplemental DPRJEA. Long-term operations will not further inpact the environment. 

34 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

A vegetation monitoring program is underway. Baseline data, including aerial photography, was 

taken during the growing season before operations began and is being compared against similar data 

gathered since. Continuation or cessation of the program will be contingent upon the observed 

results. If it is established that the decreased salinity benefits the vegetative community, monitoring 

will cease. 

Public Involvement and Information 

Throughout the study phase for the project modifications, the public and interested and affected 

agencies, groups, and individuals had the opportunity to participate in the study. Reclamation 

considered the information. opinions, and expressed desires of the public in evaluating project 

development and the salinity problem. Reclamation also coordinated with and received assistance 

from the Service, BLM, and CDOW. General information on project development was provided to 

local residents through newspapers, radio and television programs, and public meetings. 

35 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Chapter 5 - References Cited 

Bureau of Reclamation. n.d. Biological Assessment. ModifY Operation of McPhee 

Reservoir and Acquire Additional Water for Fish and Wildlife Purposes. Durango, Colorado. 

Cowardin, L. M., V Carter, F.C. Golet. and E.T. LaRoe. 1979. Classification 

of Wetlands 

and Deepwater habitats of the United States. U.S. Fish and Wildlife Service, 

Washington D.C. 

Federal Register. 1995[a]. Final rule determining endangered status for the southwestern 

willow flycatcher. February 27, 1995. Vol. 60 (38), p. 10694. 

Federal Register. 1996. Endangered and Threatened Wildlife and Plants; Review of Plant 

and Animal Taxa That are Candidates for Listing as Endangered or Threatened Species. Notice 

ofReview. February 28, 1996, Vol61, No. 40, p. 7596. 

Raptor Research Foundation, Inc. 

Valdez, R.A., W.J. Masslich, and A. Wasowicz. 1992. Dolores River native fish habitat 

suitability study (UDWR Contract No. 90-2559), Report No. TR-272-02. April I 0, 1992. 

BIO/WEST Inc., Logan, Utah. 

36 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

LIST OF PREP ARERS 

Jon Ake 

Geophysicist 

Seismotectonics and Geophysics 

Denver Technical Service Center 

PhD Geophysics 

Thomas E. Beddow 

Wildlife Biologist 

Ecological Planning & Assessment 

Denver Technical Service Center 

B.S. Wildlife and Fisheries Biology 

Mac A. Caves, P.E. 

Chief of Operations, Paradox Valley Unit, 

Bureau of Reclamation 

Western Colorado Area Office-Southern Div. 

B.S. Civil Engineer 

Pamela Dale 

Engineering Draftsman 

Construction Services 

Bureau of Reclamation 

Western Colorado Area Office-Southern Div. 

Allen R. Gates 

Chief, Field Engineering 

Bureau of Reclamation 

Western Colorado Area Office-Southern Div. 

B.S. Civil Engineer 

37 

Errol Jensen 

Chief, Water Resources 

Bureau of Reclamation 

Western Colorado Area Office-Southern Div. 

M.S. Civil Engineering 

Kirk Lashmett 

Environmental Protection Specialist 

Bureau of Reclamation 

Western Colorado Area Office-Southern Div. 

B.S. Biological Science/Fisheries 

Kenneth J. Ouellette 

Chief, Construction Services 

Bureau of Reclamation 

Western Colorado Area Office-Southern Div. 

B.S. Civil Engineering 

Ralph Pasquale 

Chief, Land, Recreation, & Environmental Res. 

Bureau of Reclamation 

Western Colorado Area Office-Southern Div. 

B.S. Civil Engineering 

Stanley N. Powers 

Team Leader. Water Resources 

Bureau of Reclamation 

Western Colorado Area Office-Southern Div. 

B.S. Civil Engineering 

PARADOX VALLEY UNIT 

BIOLOGICAL ASSESSMENT 

Appendix B 

Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

BIOLOGICAL ASSESSMENT 

TABLE OF CONTENTS 

INTRODUCTION ........................................................... 1 

PROJECT AUTHORITY AND PURPOSE ........................................ 2 

PROJECT HISTORY ........................................................ 2 

PREVIOUS SECTION 7 CONSULTATION ........................................ 3 

PROJECT SETTING ......................................................... 4 

PROPOSED ACTION AND ALTERNATIVES ..................................... 6 

PROJECT IMPACTS ........................................................ 6 

CONSERVATION MEASURES ................................................ 7 

THREATENED AND ENDANGERED SPECIES ................................... 11 

AMERICAN PEREGRINE FALCON ...................................... 11 

BALD EAGLE ....................................................... 13 

BLACK-FOOTED FERRET ............................................. 15 

BONYTAIL CHUB .................................................... 17 

COLORADO SQUAWFISH ............................................. 18 

HUMPBACK CHUB .................................................. 22 

MEXICAN SPOTTED OWL ............................................. 24 

RAZORBACK SUCKER ............................................... 27 

SOUTHWEST RIVER OTTER ........................................... 29 

SOUTHWESTERN WILLOW FLYCATCHER ............................... 30 

Literature Cited ........................................................... 34 

LIST OF TABLES 

Table 1 - Summary of project impacts associated with the long term operation of the 

Paradox Unit .............................................................. 9 

Table 2 - Endangered, threatened, and candidate species addressed in the biological 

assessment .............................................................. 1 0 

Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

INTRODUCTION 

This Biological Assessment was prepared in accordance with requirements of Section 7(c) of the 

Endangered Species Act of 1973 (Act) as amended in conjunction with the Paradox Valley Deep 

Well Injection Unit (Unit). By memoranda dated March 20, 1989; September 23, 1994; and 

subsequent informal consultations, as required by the Act, the U.S. Fish and Wildlife Service 

(Service) provided the Bureau of Reclamation (Reclamation) with names of 161isted and candidate 

species that may occur in the affected environment of the project (USFWS, 1994; 1989). The list 

was updated by communication with Mr. Terry Ireland located at the Grand Junction, Colorado, 

U.S. Fish and Wildlife Service Office, on February 29, 1996. This communication resulted in 

reducing the list to 15 species and a change in status for the bald eagle which has been downlisted 

to threatened, the flannel mouth sucker which has been listed as a category 2 species, and the 

loggerhead shrike which has also been listed as a category 2 species. A similar list identifying 

State-listed species was provided by the Colorado Division of Wildlife (CDOW) following informal 

consultations during February and March, 1995. This list was also updated by communication with 

CDOW at the Montrose District Office and by a request to the Colorado Natural Heritage Program. 

These species are identified in Table 2. 

Additional modifications have been proposed by the Service to 50 CFR Part 17, Endangered and 

Threatened Wildlife and Plants; Plant and Animal Taxa that are Candidates for listing as 

Endangered or Threatened Species. The Service issued in the Federal Register, February 28, 

1996, a Proposed Rule to reclassify those species classified as candidates. The designation of 

those species known as category 2 candidates will be discontinued and those known as category 

1 will be referred to simply as candidate species. Additional consultations were initiated to clarify 

the status of category 2 species with the Endangered Species Coordinator in the Service's Region 

6 Office and with the Chief, Division of Endangered Species in Washington, D.C. Each confirmed 

that the guidance issued in the Federal Register Notice of Review (Federal Register, 1996) for 

candidate species is the current procedure to follow and the category 2 classification no longer 

exists. As a result of this consultation, category 2 species addressed in the previous Biological 

Assessment will not be addressed in this revised document. Six species were addressed as 

category 2 species in the previous assessment. These species will not be addressed, however, 

those species listed by the State of Colorado as threatened or endangered will be addressed. 

This assessment summarizes distribution; abundance; life requisites; and potential project impacts 

on endangered, threatened, and candidate species that might be affected by the proposal to 

operate the Unit on a long term basis (Table 2). The document proposes mitigation concepts to 

address potential impacts where appropriate. At the present time, no action is the only alternative 

to the proposed action. 

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Supplemental Definite Plan Report/Environmental Assessment 

The purpose of this assessment is to promote interagency cooperation and consultation in project 

decision making which may affect listed and candidate species, and to develop possible 

conservation and mitigation measures to avoid or reduce identified impacts. 

Information presented in this assessment was obtained from field evaluations of the Unit area, 

extensive literature reviews, and communications with the Service and CDOW personnel. 

PROJECT AUTHORITY AND PURPOSE 

The Unit was authorized for construction by the Colorado River Basin Salinity Control Act of 197 4 

(PL93-320, amended; PL98-569) as part of a basinwide program to improve water quality in the 

Colorado River for the benefit of water users in the United States and Mexico. Title I of the act 

authorized construction of a desalting complex and associated measures to ensure acceptable 

salinity levels below Imperial Dam on the mainstem of the Colorado River (near Yuma, Arizona). 

Title II, which was directed toward salinity control in the United States above Imperial Dam, 

authorized construction of the Unit and three other projects. The goal of these efforts is to reduce 

salt concentrations to threshold levels adopted in 1975 by member states comprising the Colorado 

River Basin Salinity Control Forum (Forum). It is estimated that more than a million tons of salt per 

year will need to be removed from the Colorado River system by the year 2010 to meet the 

Forum's established criteria. 

The Paradox Valley has long been identified as a major contributor of salt loading in the Colorado 

River Basin. The valley overlies a fractured gypsum cap that covers a formation of salt and saltrich shale that begins at a depth of about 600 to 1,000 feet and extends downward for about 14,000 

feet. The Dolores River picks up an estimated 205,000 tons of salt annually as it crosses the 

valley, primarily from the surfacing of natural brine groundwater. The purpose of the Unit is to 

intercept the brine and prevent this substantial salt load from entering the river and degrading the 

water quality of the mainstem of the Colorado River. 

PROJECT HISTORY 

Reclamation began studies at Paradox Valley in 1971. By 1979, a Definite Plan Report and Final 

Environmental Statement had been approved recommending a plan that would prevent 

approximately 90 percent of the natural brine inflow (185,000 tons of salt annually) from entering 

the Dolores River. This would lower the salinity of the Colorado River by approximately 

16.4 milligrams per liter at Imperial Dam near Yuma, Arizona (BOR, 1979; 1978). 

The recommended plan in 1979 consisted of constructing a series of shallow brine production wells 

adjacent to the river, pumping the wells at a collective rate of 5 cubic feet per second (cfs) to 

intercept the brine, transporting the brine via a 21-mile-long pipeline and eight pumping stations 

2 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

to Dry Creek Basin, and disposing of the brine by evaporation in the 3,630-acre Radium 

Evaporation Pond. Deep well injection of brine was one of the alternatives to pumping and 

evaporation of brine discussed briefly in the environmental statement but was eliminated because 

the proposed 5-cfs disposal rate was estimated to be higher than the geologic formations could 

absorb. The Region VIII Office of the EPA reviewed the 1978 Draft Environmental Statement and 

stated that it "believes that disposal by deep well injection is the environmentally preferred solution 

and therefore should be seriously investigated for brine disposal" (BOR, 1978). Continuing 

investigations and testing of the brine well field indicated the desired reduction of brine flow into the 

river could be achieved by disposing of 1.5 to 2.0 cfs of brine instead of the 5.0 cfs. Test facilities 

were constructed and a verification program was initiated in 1978. Testing proved this plan to be 

a highly effective method for controlling the brine inflow and indicated a pumping rate of 1.5 to 2 

cfs would achieve the project's goal. As a result, the brine disposal plan was re-evaluated and the 

alternative of deep well injection appeared to be more feasible. 

A consulting firm completed a feasibility study of deep well injection and concluded it to be 

technically, economically, and environmentally feasible. A testing program was designed, test 

facilities were constructed, and the testing program was initiated. 

Results of the injection test program have confirmed that injection is a physically, economically, and 

environmentally feasible method of brine disposal. However, the test program also determined that 

two injection wells would be necessary to dispose of the required brine production of 1.5 to 2 cfs. 

In 1989, Reclamation formulated an alternative project plan which incorporated 24 brine production 

wells located on both sides of the Dolores River and the construction of a second brine injection 

well. This alternative would allow the Unit to achieve the goal of 90-percent reduction in salt 

loading to the Dolores River. 

Funding constraints have eliminated the consideration of the alternative developed in 1989. The 

proposed action evaluated in this Biological Assessment is to operate the already constructed test 

facilities on a long term basis. Existing test facilities consist of one brine deep well injection unit, 

a brine production well field located on the east side of the Dolores, a relift pumping plant adjacent 

to the well field, and a 3. 7 -mile pipeline connecting the pumping station to the deep well injection 

unit. 

PREVIOUS SECTION 7 CONSULTATION 

Reclamation and the Service have been in consultation, both formally and informally, on the Unit's 

potential effects to endangered species since 1975. A memorandum from the Service dated 

February 15, 1977, rendered a conditional "no effect" opinion on the original project plan-pending 

completion of additional studies on life cycles and habitat requirements of the Colorado squawfish 

and humpback chub. A later memorandum from the Service dated October 18, 1977, 

supplemented the February 15, 1977, opinion adding that the Unit would in "no likelihood 

3 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

jeopardize the continued existence of the American peregrine falcon." These opinions were 

rendered on the preferred plan for the Unit as it was described in the 1979 FES, which included the 

3,630-acre Radium Evaporation Pond in Dry Creek Basin and an estimated pumping rate of 5 cfs 

resulting in an annual depletion to the river of 3,619 acre-feet (USFWS, 1977a; 1977b). 

In 1986, Reclamation reinitiated Section 7 consultations regarding the proposal to construct and 

operate testing facilities to evaluate injection as an alternative method of brine disposal. The 

Service responded to the proposal in a Planning Aid Memorandum dated May 4, 1988 (USFWS, 

1988), concurring with Reclamation's assessment that the testing program would have no effect 

on the project area's listed terrestrial species, but expressing concern that "any net depletion of 

water from the Upper Colorado River Basin may affect the listed endangered fish." As a result of 

this "may affect" determination, the Service requested that formal consultation be initiated. 

Subsequent formal consultation resolved the testing program's flow-related issues with a 

commitment by Reclamation to offset depletion-caused impacts during the testing period with 

releases from McPhee Reservoir of up to 1,086 acre-feet and to reinitiate formal consultation when 

a final plan was developed. 

In early 1989, based on the new information from the injection testing program, Reclamation 

reinitiated formal Section 7 consultation. The new proposed action consisted of the development 

of 2 injection wells, 24 brine production wells located on both sides of the Dolores River, and an 

estimated pumping rate of 1. 5 to 2 cfs resulting in a depletion to the river of 1 ,086 to 1 ,448 acrefeeUyear. In March 1989, Reclamation completed a Biological Assessment on the proposed action 

and concluded that (1) none of the listed terrestrial species would be adversely affected and (2) the 

minor annual flow depletions estimated at 1 ,448 acre-feet/year could be mitigated under the 

exemption described in the Recovery Implementation Program for Rare and Endangered Fish 

Species in the Upper Colorado River Basin and/or would be offset by the anticipated improvement 

in downstream water quality that would result from interception and removal of the valley's brine 

inflows (BOR, 1989). The Service did not concur with the "no affect" determination for the 

endangered fish but concluded the proposed action was not likely to jeopardize the continued 

existence of the fish and would result in an incidental take of zero. 

Current consultations, including this Biological Assessment, are updating the list of threatened and 

endangered species that might be affected by the project and addressing the potential impacts that 

may result from implementation of the proposed action. 

PROJECT SETTING 

The Unit is located in the Paradox Valley which is located in extreme western Colorado in Montrose 

County. The area lies within the Juniper-Pinyon Woodland+Sagebrush-Saltbrush Mosaic Section 

of the Colorado Plateau Province Ecoregion. The climate in this section is characterized by cold 

winters, hot summer days, and cool nights. Annual average temperatures are 40° to 55 oF and 

decrease as altitude increases. Average annual precipitation is about 20 inches but less than 

10 inches in some parts of the province. Soils are Entisols along the floodplains of major streams 

4 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Irrigated land occupies much of the valley floor to the west of the river, with major crops consisting 

of alfalfa, grains, and pasture. Sagebrush communities occupy most of valley east of the river. 

The under story is sparse and consists of perennial grasses and mixed annual forbs. In many 

areas, overgrazing has reduced the under story to primarily cheatgrass. 

The greasewood community is found in the vicinity of the brine well field, along East Paradox 

Creek, and in other intermittent drainages and arroyos in eastern Paradox Valley and Dry Creek 

Basin. The dominant plant is black greasewood which may be found in association with other 

species such as seablite and scattered big sagebrush. In most instances, the under story is very 

sparse or totally absent. Seablite is the dominant plant in areas near the well field where 

greasewood is not found. In general, little or no under story of grasses is present in these areas, 

which are characterized by salt-encrusted ground. 

Pinyon-juniper woodland is found on the slopes of Paradox Valley and on the surrounding mesas. 

Pinyon pine and Utah juniper predominate, although Rocky Mountain and common juniper are also 

present. The under story consists of woody shrubs, such as mountain snowberry, antelope 

bitterbrush, mountain mahogany, and serviceberry. Also found in this community are big 

sagebrush, rabbitbrush, prickly pear cactus, and various forbs and grasses. 

PROPOSED ACTION AND ALTERNATIVES 

The proposed action is to continue operating the already-constructed test injection facilities as the 

Unit's permanent contribution to the salinity control effort. While the proposed action does not 

achieve the Unit's original goal of eliminating 90 percent of the salt entering the Dolores River in 

Paradox Valley, it does provide significant reduction in the total salt loading to the Colorado River 

without expenditure of additional construction dollars. The proposed action will also reduce water 

depletions to the Dolores River. The Unit, as presently constructed, would be able to achieve an 

approximate 64-percent reduction in the natural salt loading to the river, thus, preventing 

approximately 128,000 tons of salt from entering the Colorado River system annually. This 

estimate is based on the present facility's ability to inject a mixture of 70 percent brine and 30 

percent fresh water with an 80 percent plant factor. 

Due to funding limitations, the only alternative considered is no action. Under this alternative, 

existing facilities would be abandoned and salinity control efforts would be discontinued in the 

Paradox Valley. Approximately 205,000 tons of salt would continue to enter the Dolores River 

annually. No benefits would be realized from the substantial investment made in the Unit to date. 

PROJECT IMPACTS 

The construction of the Unit is now complete and all environmental effects resulting from that 

construction have occurred. Facilities constructed include the injection well and facilities located 

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Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

and Aridisols occupy the plateau tops, older terraces, and alluvial fans. Badlands of rough, broken 

land are extensive in the mountains and on plateaus (Bailey, 1980). Reclamation has maintained 

a weather station at bedrock near the facility since 1975. During this time, the average annual 

precipitation has been about 8 inches, occurring primarily from July through October in the form 

of afternoon thunderstorms. Temperatures have varied from daytime highs of about 100 oF in the 

summer to nighttime lows of about -20 oF in the winter. 

The Unit is situated at the first 1.2 miles of the Dolores River Canyon upstream from the valley. 

Paradox Valley is from 3 to 5 miles wide, approximately 24 miles long, and aligned on a northwestsoutheast axis. Elevations in the area vary from under 5,000 feet along the Dolores River to about 

7,000 feet on the divide between the valley and Dry Creek Basin. This area is characteristic of the 

semiarid Southwestern United States with low precipitation and humidity, abundant sunshine, high 

evaporation rates, and wide ranges in daily high and low temperatures. Communities in the area 

include the two small farming towns of Paradox and Bedrock, and the larger towns of Nucla and 

Naturita to the southeast. 

The Dolores River crosses the valley perpendicularly near its midpoint, and eventually confluences 

with the Colorado River approximately 70 miles downstream from the valley. In crossing the valley, 

the river picks up an estimated 205,000 tons of salt annually primarily from the surfacing of highly 

saline groundwater. Salinity levels over 260,000 mg/L (nearly eight times as saline as seawater) 

have been recorded in brine groundwater pumped from wells near the river. About 7 miles 

downstream of the valley, the Dolores' major tributary-the San Miguel River-joins the mainstem 

and provides a source of "dilution" for the salt-laden Dolores, particularly during periods of low flow. 

Vegetation composition and density in the general vicinity of the Unit varies according to the 

seasonal availability and quality of water and soil type. Vegetation communities include riparian 

associations along the Dolores River and West Paradox Creek; irrigated agriculture in the western 

portion of Paradox Valley; sagebrush and semidesert shrublands of greasewood, seablite, and 

winterfat-snakeweed in the eastern portion of the valley; and pinyon-juniper woodland at the higher 

elevations on the sides of the valley. 

The riparian vegetation is dominated by tamarisk, which varies from sparse along the river to dense 

groves up to 100 yards wide along West Paradox Creek. Grasses, with rushes in marshy areas, 

form the under story on the west bank of the river, while no significant under story is found on the 

east bank. Stands of cottonwood trees are scattered along both sides of the river upstream from 

the confluence with West Paradox Creek, with a tall shrub under story of New Mexico forestiera 

and a lower under story of grasses. In the area of the brine production well field (area of brine 

groundwater) and downstream along the river, the riparian vegetation consists almost entirely of 

sparse tamarisk with little to no under story. 

5 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

approximately 1.2 miles south from Colorado Highway 90, a 20-foot-wide access road to the 

injection well, a brine production well field located on the east side of the Dolores River, a relift 

pumping plant adjacent to the brine production field, a 3. 7 -mile buried pipeline running from the 

brine well field to the injection well, and a 69-kV powerline from Highway 90 to the injection well. 

The 1979 Final Environmental Statement addressed impacts to the environment which would result 

from construction of the Unit's brine well field. The 1986 Final Environmental Assessment entitled 

"Deep Well Injection Testing Program" described the environmental affects of the construction and 

operation of the Unit facilities in a test mode and concluded with a finding of No Significant Impact 

(BOR, 1986a; 1986b}. 

The continued permanent operations of the facility will not result in any additional impacts other 

than those which have already occurred to listed or candidate species in the area except for annual 

water depletions to the Dolores and Colorado Rivers of approximately 516 acre-feet/year. The 

operation of the test unit would result in 3,103 acre-feet/year less depletions from the original 

proposal to pump to the evaporation pond and 932 acre-feet/year less depletions than if two deep 

injection well units were operated. The construction of an additional deep injection unit is no 

longer feasible due to funding limitations. However, the reduction in water depletions will also 

result in the increase of brine water into the Dolores and Colorado Rivers, and the goal of reducing 

natural brine inflows by 90 percent will not be achieved. Potential project impacts to threatened 

and endangered species and conservation measures are summarized in Table 1. 

CONSERVATION MEASURES 

Several conservation measures and other actions have been or will be implemented to protect and 

conserve endangered fish in the Dolores and Colorado Rivers. The Recovery Implementation 

Program for Endangered Fishes in the Upper Colorado River Basin has been executed to recover 

the four endangered fishes indigenous to the basin while providing for existing and new water 

developments to proceed in the Upper Colorado River Basin. The Service has determined that the 

Recovery Program has made sufficient progress for projects which deplete less than 3,000 acrefeet/year to go forward, subject to payment of a depletion charge. Reclamation is not subject to 

this charge since it is a participant in the Recovery Program and contributes annually to the 

program's $3 million operating budget (USFWS, 1994). 

Reclamation has proposed to modify the operation of McPhee Reservoir located on the Dolores 

River 15 miles north of Cortez, Colorado, for fish and wildlife purposes (BOR, n.d.). Reclamation 

proposes to modify water releases and acquire additional water to increase the total volume for fish 

and wildlife purposes. Endangered and other fish species in the Dolores River would benefit from 

the proposed modifications since normal operations at McPhee Reservoir result in low flows in the 

Dolores River during dry years, and all alternatives would increase flows in the Dolores River. 

Releases from McPhee Reservoir could supplement water depletions to the Dolores River resulting 

from operation of the Unit. 

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Supplemental Definite Plan Report/Environmental Assessment 

Other conservation measures implemented with the project include design of new transmission 

lines to prevent electrocution of raptor species that utilize the area. Financial contributions were 

also transferred to the CDOW to assist in transplanting chukars to the Paradox Valley to provide 

additional recreational opportunities and an additional prey base for raptors in the valley. 

8 
SPECIES 

American 

peregrine falcon 

Bald eagle 

Black-footed ferret 

Bonytail chub 

Colorado 

squawfish 

Humpback chub 

Mexican spotted 

owl 

Razorback sucker 

Southwest river 

otter 

Southwestern 

wi I low flycatcher 

Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

TABLE 1 

Summary of potential environmental impacts associated with the 

proposal to operate the Paradox Unit on a long term basis 

POTENTIAL RECOMMENDED 

PROJECT IMPACTS MITIGATION MEASURES 

No impacts; species habitat not No species-specific mitigation measures 

affected by project recommended 

No impacts; minor depletions will not No species-specific mitigation measures 

affect existing habitat. recommended. Water quality improvements 

wi II benefit species 

No impacts; species habitat not No species-specific mitigation measures 

affected by project recommended 

No impacts; minor depletions will not No species-specific mitigation measures 

affect existing habitat recommended. Water quality improvement 

and upstream flow releases will benefit 

species 

No impacts; minor depletions will not No species-specific mitigation 

affect existing habitat recommended. Water quality improvement 

and upstream flow releases will benefit 

species 

No impacts; minor depletions will not No species-specific mitigation measures 

affect existing habitat recommended. Water quality improvements 

and upstream flow releases will benefit 

species 

No impacts; affected environment does No species-specific mitigation measures 

not provide suitable habitat for species recommended 

No impacts; minor depletions will not No species-specific mitigation measures 

affect existing habitat recommended. Water quality improvement 

and upstream flow releases will benefit 

species 

No impacts; minor depletions will not No species-specific mitigation measures 

affect existing habitat recommended. Water quality improvements 

and upstream flow releases will benefit 

species 

No impacts; minor depletions will not No species-specific mitigation measures 

affect existing environment recommended. Water quality improvements 

and upstream flow releases in addition to 

control of overgrazing and exotic vegetation 

would benefit species 

9 
Paradox Valley Unit 

Supplemental Definite Plan Reporl/Environmental Assessment 

TABLE 2 

Endangered, threatened and candidate species 

addressed in the biological assessment 

STATUS1 

SPECIES 

FEDERAL STATE 

American peregrine falcon (Falco Endangered Endangered 

peregrinus ana tum) 

Bald eagle (Haliaeetus leucocephalus) Threatened Endangered 

Black-footed ferret (Mus tela nigripes) Endangered Endangered 

Bonytail chub (Gila elegans) Endangered Endangered 

Colorado squawfish (Ptychocheilus Endangered Endangered 

lucius) 

Humpback chub (Gila cypha) Endangered Endangered 

Mexican spotted owl (Strix occidental is Threatened Threatened 

lucida) 

Razorback sucker (Xyrauchen texanus) Endangered Endangered 

Southwest river otter (Lutra canadensis Not listed Endangered 

sonorae) 

Southwestern willow flycatcher Endangered su 

(Empidomax traillii extimus) 

a. Federal Endangered - Spec1es wh1ch are 1n danger of extinction w1th1n the foreseeable 

future throughout all or a significant portion of their ranges. 

Federal Threatened - Species likely to become endangered within the foreseeable future 

throughout all or a significant portions of their ranges. 

State Endangered - Same as Federal Endangered. 

State Threatened - Same as Federal Threatened. 

State SC (Species of Special Concern) -Native species for which data indicate that there is 

a long term downward trend in numbers and distribution and the decline is likely to lead to 

threatened or endangered status. Also, recently delisted species whose abundance and 

distribution are stable and growing or whose abundance and distribution have attained 

Recovery Plan or Conservation Plan goals within the past 5 years. 

State SU (Species of Undetermined Status) - Native species for which historical and current 

data are inadequate to demonstrate a decline in numbers or distribution. 

a. All native populations of L. canadensis were believed to have been extirpated from Colorado 

in the 1900's. The State Endangered status applies to all populations of otters that have been 

reintroduced throughout the state, regardless of species and/or subspecies. 

10 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

THREATENED AND ENDANGERED SPECIES 

Reclamation requested a list of threatened and endangered species that may be present in areas 

affected by the proposed action. The Service identified listed, proposed listed, and candidate 

species to be added to the latest project list. The table on the following page shows the 

endangered, threatened, and candidate species identified by the Service. 

While the Endangered Species Act does not require Federal agencies to address candidate 

species in a biological assessment, Reclamation recognizes the importance of addressing 

potentially threatened species to assist in preventing further decline of the species ultimately 

requiring formal protection under the Act. However, due to the issuance of new procedures for the 

classification of candidate species by the Service, no candidate species are identified that will be 

affected by the project. 

AMERICAN PEREGRINE FALCON 

(Falco peregrinus anatum) 

Status, Distribution, and Abundance 

Three subspecies of peregrine falcons are found in North America. The subspecies endemic to 

Colorado is Falco peregrinus anatum. This subspecies was listed by the Service as endangered 

in 1970 and is listed by the State of Colorado as an endangered species. F. peregrinus anatum 

occurs from Mexico north to the arctic tundra. 

Evidence indicates that the peregrine falcon was present in the Western United States at least 

30,000 years ago. Historically about 180 pairs of peregrines nested in the Rocky 

Mountain/Southwest Region. In the 1950's, the breeding populations throughout much of the 

Northern Hemisphere began an unprecedented decline. F. peregrinus anatum has shown the most 

drastic decline. In 1964, six of 31 historic nest sites in Colorado were occupied. In 1975, seven 

of 25 historic peregrine falcon sites visited in Colorado had pairs. A decline in active peregrine 

falcon aeries in the northwestern and other sections of the United States prior to 1948 were 

attributed to changes in climate (increases in temperature and decreases in precipitation); however, 

the major causes for declines have been attributed to DDT contamination leading to eggshell 

thinning. Other causes leading to the demise of the peregrine falcon include shooting, poisoning 

by pesticides, destruction of nestlings, and interference at the nest causing abandonment or 

interruption of parental care (Rocky Mountain/Southwestern Peregrine Falcon Recovery Team, 

1977). 

Peregrine falcons occur in the Dolores River Canyon upstream from Paradox Valley and in the 

Paradox Valley area. An aerie is located approximately 44 miles downstream from McPhee Dam, 

and two other nesting pairs are located along the river between Slick Rock and Bedrock, Colorado 

(Colorado Division of Wildlife unpublished data, 1993). 

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Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

In the early summer of 1977, a peregrine falcon aerie was discovered on the north end of Paradox 

Valley approximately 1 mile north of the Unit's temporary evaporation pond high on a precipitous 

cliff (BOR, 1977). While the falcons have periodically relocated the aerie along this cliff from year 

to year, the same nesting pair successfully nested through 1995 (Pers. Comm. Bob Welch, BLM, 

1995), and CDOW confirmed nesting activity also up through 1995 (Tom Beck, 1996). The 

Colorado Natural Heritage Program confirmed a breeding occurrence in 1994 (Grunau, 1996). 

Through this period, construction and testing of various project facilities have not adversely affected 

nesting success of the peregrines. 

Life Requisites 

The habitat requirements of the peregrine falcon may be divided into three parts: (1) nesting sites, 

the cliff or substrate upon which eggs are laid, young are reared, and reproduction activities take 

place; (2) hunting sites, the environs or territory where food is obtained; and (3) migration and 

wintering sites, the winter resting and hunting sites or habitats through which it migrates (Rocky 

Mountain/Southwestern Peregrine Falcon Recovery Team, 1977). 

Nesting Sites. - Peregrine falcons in the Rocky Mountains and Southwest Region now persist 

mainly on mountain cliffs and river gorges. Active aeries are usually present upon cliffs which 

exceed 200 feet in height. Nests are situated on open ledges, and a preference for a southern 

exposure increases with latitude. Peregrines nest from the lowest elevations in the region to above 

9,000 feet, but nesting above 8,500 feet is rare. In the Rocky Mountain Region, the majority of 

known remaining pairs are near scrub-oak or pinyon-juniper woodlands. Prey abundance and 

diversity provided by these situations are probably a major factor in aerie selection. Nest sites also 

are adjacent to water courses and impoundments because of the abundance of avian prey 

frequenting such areas. 

Hunting Sjtes. - Peregrines may travel up to 17 miles from nesting cliffs to hunting areas. Flight 

speeds in excess of 60 miles per hour allow this falcon to hunt large areas with little effort. 

Preferred hunting habitats are cropland, meadows, river bottoms, marshes, and lakes which attract 

abundant bird life. The peregrine's principal food items are passerine birds, waterfowl, and 

shorebirds. 

Migration. -Migratory behavior is largely restricted to F.p. tundrius falcons, although F.p. anatum 

in the more northern latitudes will move southward if the food supply is not adequate for the winter 

(Snow, 1972). 

Consequences of the Proposed Action 

The Unit has been constructed and operated in a test mode for several years and nesting activity 

was reported through 1995. The minimal water depletions resulting from this action would not 

change or affect the habitat for the peregrine falcon. The proposed action will not impact or change 

12 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

the existing environment, therefore, it will not affect peregrine falcon nesting, hunting, or migration 

habitat. 

Recommended Mitigation Measures 

In order to prevent electrocution of raptors, all powerlines at the Unit were constructed to conform 

with criteria outlined in Suggested Practices for Raptor Protection on Powerlines -The State of the 

Art. 1981; Raptor Research Foundation, Inc. In addition, efforts to supplement the prey base for 

peregrine falcons and other raptors have been attempted by the release of chukar. Since the 

proposed action would not affect the existing environment, no additional mitigation measures would 

be implemented for the peregrine falcon. 

Summarv of Project Impacts 

All disturbances resulting from construction and operation of the Unit have occurred. Minor water 

depletions would result from the proposal to operate the already constructed test facility on a long 

term basis. Peregrine falcons utilize the Paradox Valley and riparian habitats as feeding and 

migratory habitat. Additional depletions to the Dolores River would not affect peregrine habitat; 

therefore, the existing prey base would not be affected, and peregrine falcons would not be 

impacted by the proposed action. 

BALD EAGLE 

(Haliaeetus leucocephalus) 

Status, Distribution and Abundance 

The first listing of the bald eagle occurred in 1967 when the Service listed the southern bald eagle 

as endangered (March 11, 1967; 32 FR 4001 ). This listing was made under the Endangered 

Species Preservation Act of 1966 and did not include the northern bald eagle primarily because 

the Alaskan and the central and western Canadian populations of that subspecies were not 

considered endangered. Subsequently, the Service published a second bald eagle ruling (February 

14, 1978; 43 FR 6233) under the authorities granted by the Act, listing the bald eagle as 

endangered throughout the 48 conterminous states, except in Washington, Oregon, Minnesota, 

Wisconsin, and Michigan where it was listed as threatened. 

The bald eagle has been reclassified from endangered to threatened. The Service issued notice 

on July 12, 1994, to reclassify the bald eagle from endangered to threatened in most of the lower 

48 states (Federal Register, 1994b). The Final Rule to reclassify the bald eagle from endangered 

to threatened was published in the Federal Register July 12, 1995, with an effective date of August 

11, 1995 (Federal Register, 1995). 

The bald eagle has an overall range encompassing Canada, Alaska, northern Mexico, and the 

13 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

48 conterminous states. Wintering bald eagles begin arriving in southwestern Colorado in October 

and November and usually depart by March or April. Numerous raptor surveys were conducted 

by the CDOW in 1976, and aerial reconnaissance surveys were conducted by the Service in both 

1985 and 1986 for evidence of endangered raptors. While numerous wintering bald eagles were 

observed in the general area, no bald eagle aeries were observed within the Unit affected area. 

Bald eagles are known to prefer fish and waterfowl for food. Most of the wintering bald eagles have 

been observed in the Dry Creek Basin areas, southeast of Paradox Valley. The Dolores River is 

not a part of the annual CDOW midwinter bald eagle surveys. The predominant wintering use 

appears to be the 20-mile stretch of the river below McPhee Dam (Beck, 1996). Since there is little 

open water in the area during the winter months, fish and waterfowl probably comprise a small 

percentage of their winter diet. Instead, eagles are commonly seen feeding on carrion, primarily 

sheep, deer and elk (BOR, n.d.). 

Life Requisites 

Wintering bald eagles are associated with unfrozen lake, river, and wetland habitats. Distribution 

is dependent on prey density, suitable perch and roost sites, weather conditions, and freedom from 

human disturbance (Ohmart and Sell, 1980). Eagle numbers normally fluctuate considerably at 

particular wintering areas. 

Although most wintering eagles depend primarily on fish, other prey is also taken including jack 

rabbits, waterfowl, and carrion (Spencer, 1976). Food habits of the bald eagle are opportunistic 

and vary regionally in the Southwest. Important food items include fish, especially carp, channel 

catfish, waterfowl, carrion, and small mammals. Dams have caused changes in wintering bald 

eagle distribution by concentrating populations to newly created food sources. The presence of 

a fishery does not necessarily ensure its attractiveness to bald eagles. Eagles often depend on 

fish that are dead, dying, or otherwise vulnerable (Steenhof, 1978). 

Communal roosting is prevalent in wintering bald eagles with protection from the wind being a 

primary consideration (Steenhof, 1978). The night roost is almost invariably a tree protruding 

above the forest canopy which permits an unobstructed approach and takeoff. The absence of 

small branches makes a dead tree or snag the perch-of-choice (Spencer, 1976). 

Diurnal hunting and loafing perch sites are usually trees with large horizontal branches, bordering 

open areas, especially on the edges of rivers or lakes. Proximity to a food source and visibility are 

key factors influencing perch selection by eagles (Steenhof, 1978). Eagles often select the tallest 

trees available with branches overlooking a food source. Specific trees and even branches are 

habitually used. 

Bald eagles are sensitive to human activities and may abandon favorable sites if disturbed. 

Although bald eagles can become conditioned to automobile traffic, vehicles such as motor boats 

and snowmobiles disrupt eagle activity patterns. Hunting and chainsaw activities have been known 

to displace eagles from winter roosting areas (Steenhof, 1978). 

14 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Most populations appear to be recovering from earlier reproductive difficulties associated with DDT 

and related chemical contamination. Illegal shooting remains the greatest single known source of 

bald eagle mortality. Roughly half of all recorded bald eagle deaths are a direct result of shooting 

(Evans, 1982). 

Consequences of the Proposed Action 

All disturbances associated with the construction and operation of the Unit have already occurred. 

Preliminary conclusions, based upon the Animas-La Plata bald eagle habitat surveys, indicate 

prime bald eagle habitat for roosting and feeding activities in southwestern Colorado consists of 

cottonwood forests or isolated cottonwoods usually located adjacent to wetlands (BOR, 1994). 

This type of habitat exists in the area on the west side of the Dolores River and upstream from the 

area of disturbance on the east side. The main water depletions associated with pumping from the 

brine well field occur downstream of prime bald eagle habitat associated with existing cottonwood 

forest and will not be affected by the project. 

Recommended Conservation Measures 

In order to prevent electrocution of raptors, all powerlines at the Unit were constructed to conform 

with criteria outlined in Suggested Practices for Raptor Protection on Powerlines - The State of the 

Art. 1981; Raptor Research Foundation, Inc. The proposed modifications in the operation of 

McPhee Reservoir and improved water quality resulting from operation of the Unit will enhance 

fisheries and waterfowl habitat and improve the food base for the bald eagle. 

Summarv of Project Impacts 

There would be no impacts resulting from the proposed project that would impact the bald eagle. 

BLACK-FOOTED FERRET 

(Mustela nigripes) 

Status, Distribution and Abundance 

Widespread poisoning of prairie dogs and agricultural cultivation of their habitat drastically reduced 

prairie dog abundance and distribution in the last century. Sylvatic plague, which may have been 

introduced to North America around the turn of the century, also determined prairie dog numbers, 

particularly in the southern portion of their range. The severe decline of prairie dogs nearly resulted 

in the extinction of black-footed ferrets. The ferret's decline may be partially attributable to other 

factors such as secondary poisoning from prairie dog toxicants and canine distemper. The blackfooted ferret was listed by the Service as an endangered species on March 11, 1967 (Federal 

Register, 1995). 

15 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Historically, the black-footed ferret was found over a wide area, but it is difficult to make a 

conclusive statement on its historical abundance due to its nocturnal and secretive habits. The 

historical range of the species, based on specimen collections, includes 12 states (Arizona, 

Colorado, Kansas, Montana, Nebraska, New Mexico, North Dakota, Oklahoma, South Dakota, 

Texas, Utah, and Wyoming) and the Canadian Provinces of Alberta and Saskatchewan. There is 

prehistoric evidence of this ferret occurring from the Yukon Territory in Canada to New Mexico and 

Texas (Federal Register, 1995). 

There are no historical records indicating black-footed ferrets ever occurred in Paradox Valley. 

However, Paradox Valley once contained a large population of Gunnison prairie dogs (Cynomys 

gunnisoni zumiensis), a preferred food source for the ferret (Cressey and Grad, 1975). They 

further state these prairie dog populations have been greatly reduced by human extermination. 

Currently, remnant populations of prairie dogs exist sporadically in the valley at ground elevations 

where the water table is relatively low. 

Life Requisites 

Black-footed ferrets primarily prey on prairie dogs and use their burrows for shelter and denning 

and depend almost exclusively on prairie dogs for food and shelter (Federal Register, 1995). 

Although black-footed ferrets observations have been reported in prairie dog towns as small as 14 

acres in South Dakota, more recent information suggests that minimum habitat requirements are 

much larger. At one time near Meeteetse, Wyoming, an estimated 40 to 60 adult ferrets were 

supported by 21 prairie dog towns covering 6,000 to 7,200 acres with mean burrow densities of 4 

or more per acre (Clark, 1989). The 21 colonies averaged 338 acres each and covered 8.5 percent 

of the Meeteetse study area (USFS, 1989). The smallest town supporting an adult ferret at the 

Meeteetse site was approximately 118 acres (Clark, 1989). Minimal habitat for black-footed ferrets 

in South Dakota should support at least eight prairie dog colonies per township, with each dog town 

covering at least 

30 acres, and two or more colonies covering at least 100 acres (Hillman et al., 1979). This 380 

acres per township was considered a minimum habitat size for black-footed ferrets. 

Consequences of the Proposed Action 

There is evidence that small remnant prairie dog towns may exist along West Paradox Creek of 

the site; however, based upon past studies, these prairie dog towns-if active-are far too small 

to support black-footed ferrets. 

All populations of prairie dogs are located away from project features or disturbances; therefore, 

we do not believe these prairie dog populations or any rare chance of associated black-footed 

populations would be affected by the proposed action. 

16 
Recommended Mitigation Measures 

Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Since the proposed action will not affect prairie dog towns or black-footed ferret habit, no mitigation 

measures will be implemented for the black-footed ferret. 

Summary of Project Impacts 

All disturbances associated with the construction and operation of the Unit have occurred, and no 

impacts to the black-footed ferret will result from the long term operation of the Paradox Unit. 

Status, Distribution, and Abundance 

BONYTAIL CHUB 

(Gila elegans) 

Bonytail chub were listed as an endangered species on April 23, 1980. In the upper basin of the 

Colorado River, critical habitat is designated for the bonytail chub in portions of the Colorado, 

Green, and Yampa Rivers (Federal Register, 1994b). The bonytail chub is also listed as 

endangered in Colorado and protected in Utah (USFWS, 1987). The primary causes of decline of 

this species have been listed as changes in land use patterns, water development, competition 

from nonnative fishes, and hybridization with other introduced species. 

Bonytail chub were historically found to be widespread and abundant in rivers throughout the 

Colorado River Basin, however, populations have been greatly reduced. This species is now one 

of the rarest native fish in the basin. A small number of old fish (i.e., ages of 40 years or more) are 

all that remain living in the wild, and recruitment is thought to be virtually nonexistent. Nowhere has 

reproductive success been documented. In the lower basin, a small population persists in the 

Colorado River in Lake Mohave and there are recent records from Lake Havasu. In the upper 

basin, recent captures have occurred in Dinosaur National Monument on the Yampa River, 

Desolation and Gray Canyons on the Green River, and Black Rocks and Cataract Canyon on the 

Colorado River (Federal Register, 1994b). 

Bonytail chubs have never been reported occurring in the Dolores River (Valdez et al., 1982) and 

were not reported during recent surveys of the Dolores River carried out by Bio/West (Valdez et 

al., 1992). Portions of the Dolores River, especially the section between Bradfield Bridge, 10 miles 

downstream of McPhee Dam and Paradox Valley, may offer suitable habitat for future bonytail 

reintroductions (BOR, 1989). 

Life Requisites 

The bonytail chub is adapted to mainstream rivers, where it has been observed in pools and 

17 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

eddies. In reservoirs, the fish occupies a variety of habitat types. In Lake Mohave, the bonytail 

chub has been observed in eddy habitats. Spawning requirements have never been documented 

in a river, but it is reported that spawning occurs in June and July at water temperatures of about 

64 "F. The available data suggest that habitats required for conservation of the bonytail chub 

include river channels, and flooded, ponded, or inundated riverine habitats that would be suitable 

for adults and young, especially if competition from nonnative fishes is reduced (Federal Register, 

1994bc). Proposed modifications in the operation of McPhee Reservoir to increase flows during 

the summer and dry years should enhance the aquatic habitat of the bonytail chub and supplement 

water depletions resulting from the long term operation of the Unit. 

Consequences of the Proposed Action 

The minor depletions of 516 acre-feet/year resulting from the proposed action would not affect the 

bonytail chubs or their designated critical habitat. The improved water quality in the Dolores and 

Colorado Rivers resulting from the proposed action will benefit the bonytail chub and the aquatic 

resources the species is dependent upon in its environment. 

Recommended Mitigation Measures 

No mitigation measures for the bonytail chub are recommended; however, improved water quality, 

which is the primary goal of the long term operation of the Unit, should benefit the species. 

Summary of Project Impacts 

The long term operation of the Unit would result in minor water depletions. However, these 

depletions should not affect the bonytail chub and should be offset by improvements in water 

quality. Proposed modifications in the operation of McPhee Reservoir should supplement water 

depletions resulting from the long term operation of the Paradox unit. 

COLORADO SQUAWFISH 

(Ptychocheilus lucius) 

Status, Distribution, and Abundance 

The Colorado squawfish was first classified as endangered on March 11, 1967, and was later given 

full protection under the Endangered Species Act of 1973 following formal listing in January 197 4 

(Federal Register, 1974). In the upper basin of the Colorado River, critical habitat is designated 

for the Colorado squawfish in portions of the Colorado, Green, Yampa, White and San Juan Rivers 

(Federal Register, 1994b). Colorado squawfish are the only federally protected fish species 

addressed in this assessment which have been historically reported from the Dolores River (Valdez 

et al., 1992). Colorado squawfish are also designated as endangered by the CDOW and have 

been granted some form of protected status in all of the remaining Colorado River Basin states 

18 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

(USFWS, 1987). The cause of the decline of the Colorado squawfish is unknown but is probably 

related to a combination of factors including direct loss of habitat, changes in flow regime, blockage 

of migration routes, water temperature changes, and interactions with introduced fish species 

(USFWS, 1987). 

Colorado squawfish were once abundant in the mainstem of the Colorado River and most of its 

major tributaries in Colorado, Wyoming, Utah, New Mexico, Arizona, Nevada, California, and 

Mexico. The remaining native populations total fewer than 10,000 adult individuals and are 

restricted to the upper basin in Colorado, Wyoming, Utah and New Mexico (USFWS, n.d.). The 

largest populations are found in segments of the Green, Yampa, White, Gunnison, and Colorado 

Rivers above Lake Powell and there is a small reproducing population in the San Juan River 

(Federal Register, 1994bc; Maddux et al., 1993). In the lower basin, the last known adult Colorado 

squawfish was taken by a fisherman in 1975 from the mouth of Havasu Creek. Lower basin 

recovery efforts in recent years have included the reintroduction of over 300,000 hatchery-reared 

fish into several locations, including the Salt and Verde Rivers in Arizona (Maddux et al., 1993; 

USFWS, n.d.). 

Colorado squawfish spawning has been documented in canyons in the Yampa and Green Rivers 

(Tyus, 1991 ). Reproduction is associated with declining flows in June, July, and August and 

average water temperatures ranging from 22 to 25 oc (72 to 77 °F). River-mile 130 on the 

Colorado River, near the Colorado-Utah State line, also has been identified as a spawning site, and 

radio-tagged aduHs have moved to a specific 0.1-mile-long section in four different years 

(Osmundson and Kaeding, 1989; USFWS unpublished data, 1992-1993). In the mainstem 

Colorado River, spawning occurs at many locations (McAda and Kaeding, 1991). They also 

suggested that Colorado squawfish spawning in the Colorado River may have been adversely 

impacted by construction of mainstem dams and a 48-percent reduction in peak discharge. On the 

San Juan River, a spawning reach has been identified between river-miles 133.4 and 129.8, near 

the confluence of the Mancos River (Ryden, 1995). 

The Service (USFWS, 1994) considers the Dolores River to be Colorado squawfish habitat based 

on historic records of occurrence in the drainage. Small squawfish have been collected from 

unidentified locations in the Paradox Valley as late as 1962 (Seethaler, 1978). The Dolores River 

may have functioned as a spawning tributary for breeding populations inhabiting the upper 

Colorado River in the vicinity of the confluence of the two rivers (Valdez et al., 1992). No reports 

or records of occurrence were found that indicate Colorado squawfish occupied or utilized the 

Dolores River upstream of Paradox Valley. 

Colorado squawfish were rarely found and, in some cases, reported to be absent from the lower 

Dolores River above the Colorado/Utah State line by the 1950's and 1960's, (Valdez et al., 1982). 

Conditions likely worsened in the mid-1960's as recurrent spills and leeching of uranium mill wastes 

into the San Miguel River near the town of Uravan decimated much of the aquatic life in the 60-mile 

reach of the Dolores River from the confluence of the San Miguel River to the confluence with the 

19 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Colorado River (Valdez et al., 1992). 

No squawfish were found in a 1971 survey of the Dolores River from the town of Dolores to the 

confluence with the Colorado River (Holden and Stalnaker, 1975). In 1981, similar findings were 

reported in an extensive fishery and aquatic habitat survey of the river from the Paradox Valley to 

the Colorado River (Valdez et al., 1982). This led the authors to speculate that the only probable 

area in the Dolores River that squawfish may periodically exist would be in close proximity to the 

Colorado River confluence. In subsequent surveys conducted in 1990 and 1991, four Colorado 

squawfish were captured in the lower 177 miles of the Dolores River from Bradfield Bridge to the 

confluence with the Colorado River (Valdez et al., 1992). All of these squawfish were collected in 

1991 and were captured within 1.25 miles of the confluence with the Colorado River. It is not 

known whether these fish were temporarily using the Dolores River or were permanent residents; 

however, their close proximity to the Colorado River may indicate that these fish were only 

temporary inhabitants. 

The apparent decline of the Colorado squawfish in the Dolores River has been tied to a 

combination of human-induced and naturally occurring conditions. Alteration of the river's historic 

habitat can largely be traced to flow changes (mainly low summer flows) associated with irrigation 

diversions, contamination from uranium mills near the towns of Uravan and Slick Rock, and the 

proliferation of introduced species. 

In the late 1800's, a trans-basin diversion dam was constructed on the Dolores River near the town 

of Dolores by the Montezuma Valley Irrigation Company. Before completion of McPhee Dam, most 

all the flow of the river was diverted for irrigation use during late summer and early fall. The dam 

diverted nearly all of the river during the summer and fall low-flow period. The USGS gauging 

station-"Dolores River at Bedrock CO"-recorded zero flow on numerous occasions before 

completion of McPhee Dam. These low-/no-flow conditions resulted in extremely high 

concentrations of salt in the Dolores River leaving the Paradox Valley. These conditions resulted 

in the elimination of most aquatic life in the Dolores River from Paradox Valley to the confluence 

with the San Miguel (BOR, 1989). 

Uranium processing facilities operated during the late 1940's through the 1960's severely impacted 

water quality in the San Miguel and lower Dolores Rivers and may have contributed to the decline 

of the Colorado squawfish in the basin (USFWS, 1994). Several toxic spills into the San Miguel 

River are known to have occurred from the uranium processing plant located at Uravan, Colorado. 

A second uranium processing facility near Slick Rock, Colorado, was reported to be operational 

over generally the same time frame (Valdez et al., 1992). The combination of less-than-favorable 

conditions discussed above concludes that "from the standpoint of preservation of rare and 

endangered fish species, the Dolores River system appears to have little importance" (Holden and 

Stalnaker, 1975). 

20 
Life Requisites 

Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

The Colorado squawfish was once the top native carnivore in the Colorado River system. As an 

adult, it is a voracious predator capable of attaining weights exceeding 80 pounds and lengths of 

nearly 6 feet, however, specimens weighing more than 15 pounds have rarely been found since 

1970 (USFWS, 1987). Squawfish are well-adapted to the major rivers in the Colorado River Basin 

where hydraulic regimes can be characterized by variable flows, high silt loads, and periods of high 

turbulence. Young-of-the-year, juveniles, and sub-adults are most frequently found in shallow 

backwater areas with silt and sand substrates and little or no current. Older, larger squawfish 

prefer deeper, moving water but use a wide variety of habitats throughout their life cycle. Migration 

is an important component in the reproductive cycle of the Colorado squawfish. Mature adults 

have been known to migrate up to 200 miles upstream or downstream to reach spawning areas 

on the Colorado, Green, and Yampa Rivers. Tyus (1990) hypothesized that migration cues, such 

as high spring flows, increasing river temperatures, and chemical inputs from flooded lands and 

springs may be important to successful reproduction (Federal Register, 1994b). Temperature 

preferences in nature have not been established, however, evidence from the Lower Colorado 

River Basin, where water temperatures often exceed 35 'C (95 'F), suggest broad thermal limits 

for the Colorado squawfish (USFWS, 1987). 

After spawning, adult Colorado squawfish utilize a variety of riverine habitats, including eddies, 

backwaters, shorelines, and other backwater habitats (Tyus, 1990). During the winter, adult 

Colorado squawfish use backwaters, runs, pools, and eddies, but are most common in shallow, icecovered shoreline areas (Osmundson and Kaeding, 1989; Wick and Hawkins, 1989). In spring and 

early summer, adult squawfish use shorelines and lowlands inundated during typical spring 

flooding. This natural lowland inundation is viewed as important for their general health and 

reproductive conditioning (Osmundson and Kaeding, 1989; Tyus, 1990). Use of these habitats 

presumably mitigates some of the effects of winter stress and aids in providing energy reserves 

required for migration and spawning. 

In the Green River Basin, larval Colorado squawfish emerge from spawning substrates and enter 

the stream drift as young fry. The larval fish are actively or passively transported downstream for 

about 6 days, traveling an average distance of 100 miles to reach nursery areas in lower gradient 

reaches. These areas are nutrient-rich habitats that consist of ephemeral along-shore 

embayments that develop as spring flows decline (Federal Register, 1994b). Young-of-year 

Colorado squawfish are most often found in backwaters, since backwaters provide nursery and 

feeding habitat (USFWS, 1987). 

Consequences of the Proposed Action 

The minor depletions of 516 acre-feet/year resulting from the proposed action would not affect the 

Colorado squawfish or its designated critical habitat. The improved water quality in the Dolores and 

Colorado Rivers resulting from the proposed action may beneficially effect designated critical 

21 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

habitat in the Colorado River and therefore the species. 

Recommended Mitigation Measures 

No mitigation measures are recommended; however, improved water quality, which is the primary 

goal of the long term operation of the Unit, should benefit the species. 

Summary of Project Impacts 

The long term operation of the Unit would result in minor water depletions. However, these 

depletions should not affect the Colorado squawfish and should be offset by improvements in water 

quality and the potential modifications in flow releases from McPhee Dam. Proposed changes in 

the operation of McPhee Reservoir should mitigate the affects of minor water depletions that would 

result from the long term operation of the Unit. Chronic low flows from McPhee Dam, especially 

during the summer and other dry periods, would be avoided. If sufficient flows were present, the 

Dolores River would have suitable habitat for the reintroduction of experimental populations of 

Colorado squawfish (Valdez et al., 1992). 

Status, Distribution, and Abundance 

HUMPBACK CHUB 

(Gila cypha) 

The humpback chub was a member of the original list of endangered species prepared in 1964 and 

was afforded protection by the Endangered Species Act of 1973 (Federal Register, 1974). In the 

upper basin, critical habitat is designated for the humpback chub in portions of the Colorado, 

Green, and Yampa Rivers (Federal Register, 1994b). The humpback chub is also designated as 

endangered by the State of Colorado and protected by the State of Utah (USFWS, 1987). 

A combination of factors has been blamed for the decline of this fish: steam alteration (dams, 

irrigation, dewatering, and channelization); competition with and predation from introduced fish 

species; pollution and eutrophication; parasitism; changes in food base; and fishing pressure 

(USFWS, 1987). In the Yampa River, reduced spring peak flows, availability of shoreline eddy and 

deep canyon habitats, and competition and predation by nonnative fish were reported as potential 

limiting factors for humpback chub. The impact of hybridization with other species is currently 

being evaluated (Federal Register, 1994b). 

This Colorado River native was not described as a species until 1946. This has been attributed 

to the presently restricted distribution in remote, white water canyons. Humpback chub are 

medium-sized as adults ( 12-16 inches) and are well-adapted for negotiating turbulent water, having 

a pronounced dorsal hump, abruptly tapered body, and large deeply forked tail (caudal) fin. The 

historic distribution of humpback chub included large, white water canyons on the Colorado River 

system including the mainstem Colorado and four of its tributaries-the Green, Yampa, White, and 

22 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Little Colorado Rivers (USFWS, 1987). In the lower basin, the largest remaining population occurs 

in the Little Colorado and Colorado Rivers in the Grand Canyon. In the upper basin, humpback 

chub are found in the Black Rocks/Westwater Canyon and Cataract Canyon of the Colorado River, 

Desolation and Gray Canyons of the Green River, and Yampa and Whirlpool Canyons in Dinosaur 

National Monument, Green and Yampa Rivers (Federal Register, 1994b). The humpback chub has 

never been reported to occur in the Dolores River (Holden and Stalnaker, 1975). Humpback chub 

were not reported during recent surveys carried out in the Dolores River by Bio/West in 1992 

(Valdez et al., 1992). 

Life Requisites 

Humpback chub in reproductive condition are usually captured in May, June, or July, depending 

on location. Spawning occurs soon after the highest spring flows when water temperatures 

approach 66 "F. Investigators have implicated flow reductions and low water temperatures in the 

Grand Canyon as factors curtailing successful spawning of the fish in addition to increasing 

competition from other species (Federal Register, 1994b) 

Existing populations of humpback chub tend to occupy remote, specialized habitats, most often 

associated with deep, turbulent water over substrates of sand, silt, boulder, and bedrock (UFWS, 

1987). Most of the existing information on habitat preferences has been obtained from adult fish 

in the Little Colorado River, the Grand Canyon, and the Black Rocks of the Colorado River. In 

these locations, the fish are found associated with boulder-strewn canyons, travertine dams, pools, 

and eddies. Some habitat-use data also are available from the Yampa River Canyon where the 

fish occupy similar habitats and also use rocky runs, riffles, rapids, and shoreline eddies. This 

diversity of habitat use suggests that the adult fish are adapted to a variety of habitats, and studies 

of tagged fish indicate that they move between habitats, presumably in response to seasonal 

habitat changes and life history needs (Federal Register, 1994b}. 

Habitat suitable for humpback chub may exist in the section of the Dolores River between Bradfield 

Bridge, 10 river-miles downstream of McPhee Dam, to Paradox Valley. However, fish and/or 

habitat surveys for this section of the Dolores River are incomplete and not well documented. 

Limited potential existed for the recovery of Gila sp. as long as transbasin diversions continued to 

deplete the Dolores River flow during the irrigation season and poor water quality continued as a 

limiting factor to native fish populations (Valdez et al., 1982; USBOR, 1989). 

Consequences of the Proposed Action 

The minor depletions of 516 acre-feet/year resulting from the proposed action would not affect the 

humpback chub or its designated critical habitat. The improved water quality in the Dolores and 

Colorado Rivers resulting from the proposed action may beneficially affect designated critical 

habitat in the Colorado River and therefore the species. 

23 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Recommended Mitigation Measures 

Mitigation measures that might affect the humpback chub are not recommended; however, 

improved water quality, which is the primary goal of the long term operation of the Unit, should 

benefit the species. Poor water quality continues as a limiting factor to native fish populations in 

the Dolores River (Valdez et al., 1982; BOR, 1989). 

Summary of Project Impacts 

The long term operation of the Paradox Unit would result in minor water depletions. However, 

these depletions should not affect the humpback chub and should be offset by improvements in 

water quality. In addition, proposed changes in the operation of McPhee Reservoir should mitigate 

the affects of minor water depletions that would result from the long term operation of the Unit. 

Chronic low flows from McPhee Dam, especially during the summer and other dry periods, would 

be avoided which would benefit the humpback chub. 

MEXICAN SPOTTED OWL 

( Strix occidentalis Iucida) 

Status, Distribution, and Abundance 

The final rule listing the Mexican spotted owl as a threatened species under the authority of the Act 

was published in the Federal Register on March 16, 1993. The Mexican spotted owl is also listed 

as threatened in Arizona, Utah, and Colorado. The species is threatened by destruction and 

modification of habitat caused by even-aged timber harvest methods and wildfires, decreased 

habitat suitability, and potential increased predation associated with habitat fragmentation (Federal 

Register, 1994b). 

There are three recognized subspecies of spotted owls. The northern spotted owl ( Strix 

occidentalis caurina) is found from southwestern British Columbia to just north of San Francisco 

Bay; the California spotted owl ( Strix occidentalis occidenta/is) is found in the Sierra Nevada 

Mountains and the costal ranges of California south of San Francisco Bay; and the Mexican spotted 

owl ( Strix occidentalis Iucida) is found from southern Utah and Colorado through Arizona, New 

Mexico, and west Texas into the mountains of central Mexico (USFS, nd). 

In Colorado, systematic surveys conducted annually since 1989 have confirmed the rarity and 

limited distribution of S. o. Iucida in the state. Except for three adult birds in Mesa Verde National 

Park and nearby Ute Mountain Ute tribal land, all confirmed owl sightings have been in the San 

Isabel National Forest and nearby BLM lands in the Canon City area (Boyle and Franklin, 1993b). 

The most recent statewide survey results, for years 1992-1994, yielded documented sightings of 

19, 26, and 15 owls, respectively, at 13 survey sites in southwestern Colorado and the southern 

Front Range (Verner, 1995). 

24 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Results of two seasons of surveys conducted in 1992 and 1993 in suitable habitats bordering the 

Paradox Valley project area included tributaries (side canyons) of the Dolores River immediately 

upstream and downstream of the Paradox Valley; ridges adjacent to Disappointment Valley; 

Carpenter Ridge north of the town of Paradox; and side canyons of the San Miguel River near 

Norwood (Boyle and Franklin 1993a, 1993b). No evidence of Mexican spotted owls, either calls 

or sightings, was reported at any of the survey sites. Similar results were reported in surveys 

conducted during 61994 at 27 survey locations in the San Juan National Forest (Oiterman, 1995). 

The Service has identified 112 proposed critical habitat units totaling 4, 770,223 acres in Arizona, 

Colorado, New Mexico, and Utah. In Colorado, 104,103 acres were identified as potential critical 

habitat (Federal Register, 1994b). All critical habitat proposed in Colorado is located in Archuleta 

County and a very small portion of eastern La Plata County. No critical habitat is proposed in 

Montrose County in which the Unit is located. 

Life Requisites 

The Mexican spotted owl typically inhabits old growth warm- and cold-temperate forests 

characterized by steep slopes, canyons, and rocky cliffs (Federal Register, 1993b). Vegetative and 

structural preferences may vary across its range, but mixed-conifer communities appear to be the 

most frequently used. Vegetative attributes most commonly associated with preferred nesting and 

roosting habitat include high canopy closure (60 to 80 percent); a multi-layered canopy with large 

overstory trees of various species; a high incidence of mature trees with broken tops, large cavities, 

mistletoe infections, and other evidence of decadence; large snags; and accumulations of fallen 

trees and other woody debris. These habitat characteristics are best expressed in old growth 

groves (perhaps 200 years or older) with the absence of active management (Federal Register, 

1994ba). 

At the northern edge of its range in northeastern Arizona, southwestern Colorado, and Utah, 

Mexican spotted owls may occur year-round at 4,400 to 6,800 feet within the pinion-juniper zone 

below higher-elevation mixed conifer forests. These lower zones often include narrow steep-sided 

canyons exhibiting shaded, cool, and humid conditions that support dense growths of riparian and 

conifer plant associations favorable to inhabitation (Federal Register, 1993c; Federal Register, 

1994ba). 

Information on the reproductive cycle of the Mexican spotted owl is limited. Spotted owls breed for 

the first time at 2 to 3 years of age. Adult spotted owls are solitary from October through January. 

Beginning sometime in February or March, pairs on a territory begin to roost together and begin 

calling every night, especially at dusk (USFS, n.d.). Most owls lay their eggs in April with some 

reports as early as March being reported (Federal Register, 1993c). Clutch size varies from one 

to three eggs with a brood size of one or two owlets; however, broods of three occur occasionally 

in southern New Mexico (Federal Register, 1993c). The incubation period is approximately 30 days 

25 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

with most eggs hatching by the end of May. Fledgling occurs in June with the young becoming fully 

independent by October. Reproductive success can vary widely from year to year. 

Mexican spotted owls feed primarily on mammals; however, birds, reptiles, and insects also 

comprise their diet. Woodrats (Neotoma spp.) are the primary prey, especially in rock canyon 

areas. Since owls initiate their attack on prey from relatively short distances, a multi-storied forest, 

with its many potential perches, offers an advantage to the owl. Natural predators of the spotted 

owl include hawks (e.g., Accipiter gentilis, Buteo spp.) and great horned owls (Buteo virginianus) 

(Federal Register, 1993c). 

The Mexican spotted owl is threatened by (1) habitat loss as a result of logging and fires, (2) 

increased predation associated with habitat fragmentation, and until recent years, (3) lack of 

adequate protective regulations. Because the time required for spotted owl habitat to regenerate 

typically exceeds 100 years, any action that would contribute to the loss of suitable habitat will 

reduce the likelihood for survival and recovery of the Mexican spotted owl (Federal Register, 1991 ). 

Consequences of the Proposed Action 

Implementation of the proposed action will have no effect on the Mexican spotted owl. Recent 

spotted owl surveys in the general vicinity of the proposed project failed to locate any individuals 

or nesting pairs. Furthermore, none of the project facilities are located in, or adjacent to, suitable 

spotted owl nesting or roosting habitat. Furthermore, no critical habitat for the Mexican spotted owl 

has been designated in the Paradox Valley. 

Neither the anticipated improvement in downstream water quality or the small annual depletion to 

the Dolores River is expected to result in any impacts to the Mexican spotted owl or its designated 

or potential habitat. 

Recommended Mitigation Measures 

Since the proposed project would not impact the Mexican spotted owl, no mitigation measures are 

recommended for this species. 

Summary of Project Impacts 

There would be no impacts resulting from this project that would affect the Mexican spotted owl. 

26 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

RAZORBACK SUCKER 

(Xyrauchen texanus) 

Status Distribution. and Abundance 

The razorback sucker was listed as an endangered species in the Federal Register on October 23, 

1991. The razorback is listed as endangered by the State of Colorado, and protected by the State 

of Utah (USFWS, 1987). In the upper basin of the Colorado River, critical habitat for the razorback 

sucker is designated for portions of the Green, Yampa, Duchesne, Colorado, White, Gunnison, and 

San Juan Rivers (Federal Register, 1994b). 

The razorback sucker is the only member of its genus and is a member of the sucker family, 

Catostomidae. Causes for the decline of the razorback sucker have been listed as dams and 

impoundments; principally land and water use practices, changing flow regimes, and river channel 

characteristics that eliminate preferred backwater habitats (USFWS, 1987). 

The razorback sucker was once abundant throughout 3,500 miles of the Colorado River Basin 

primarily in the mainstem and major tributaries in Arizona, California, Colorado, Nevada, New 

Mexico, Utah, and Wyoming; and in the States of Baja California del Norte and Sonora of Mexico. 

These fish were most abundant downstream of present-day Lake Mead and very abundant around 

Yuma, Arizona. Razorback suckers historically occurred in most warm water reaches of the Gila 

River drainage to the New Mexico/Arizona border. Razorback suckers were abundant in the lower 

Salt River and in lower Tonto Creek and occurred in the Verde River to Perkinsville, Arizona. 

Upstream distribution in the Salt River may have been limited by extensive canyon habitat. 

In the upper basin, razorback suckers historically occurred in the Colorado, Green, and San Juan 

River Basins. Razorback suckers also were found in the Gunnison River upstream to Delta, 

Colorado. Historic distribution of razorback suckers in the Green River was from its confluence with 

the Colorado River upstream to Green River, Wyoming. Razorback suckers were reported 

common in the lower White River near Ouray, Utah, and occurred in the lower Yampa River but 

were considered rare upstream to the Little Snake River, Colorado. 

Upper basin razorback sucker distribution has been reduced to about 750 miles. The fish persists 

in the lower Yampa and Green Rivers, mainstream Colorado River, and lower San Juan River, but 

there is little recruitment in these remnant populations. The largest extant riverine population 

occurs in the Upper Green River Basin. It consisted of only 1 ,000 fish in 1989. Recent information 

suggests that this population may have declined to less than 500 fish. In the absence of 

conservation measures, it is presumed that all wild populations in the basin will soon be lost as old 

fish die without sufficient natural recruitment (Federal Register, 1994b). 

27 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

In the lower basin, several researchers noted the decline of razorback suckers shortly after 

impoundment of Lake Mead in 1935 (Maddux, 1993). Now, a substantial population exists only in 

Lake Mohave (an estimated 25,000 individuals). Small numbers of razorback suckers sporadically 

occur in Lake Mead and the Grand Canyon and below Lake Mohave in the mainstem and 

associated impoundments and canals. Successful spawning has been documented in Lake 

Mohave and numerous larvae have been collected. However, juveniles have been extremely rare 

in collections since the early 1950's (Maddux, 1993). These populations are small and recruitment 

is virtually nonexistent. The formerly large lower basin populations have been virtually extirpated 

from other riverine environments (Federal Register, 1994b). 

Life Requisites 

Razorback suckers have been observed spawning in reservoirs, but no reproductive success has 

been documented (USFWS, 1987). Habitat use and spawning behavior of adult razorback suckers 

in riverine habitats have been studied in the Green River Basin and in the upper Colorado River. 

Fish in the Green River Basin spawn in the spring with rising water levels and increasing 

temperatures. Razorback suckers move into flooded areas in early spring and begin spawning 

migrations to specific locations as they become reproductively active, and spawning occurs over 

rocky runs and gravel bars (Federal Register, 1994b). 

In nonreproductive periods, adult razorback suckers occupy a variety of riverine and impounded 

habitat types including eddies, backwaters, gravel pits, flooded bottom lands, flooded mouths of 

tributary streams, slow runs, sandy riffles, and others. Summer habitats used include deeper 

eddies, backwaters, holes, and midchannel sandbars. During winter, adult razorback suckers use 

main channel habitats similar to those used during other times of the year, including eddies, slow 

runs, riffles, and slack waters (Federal Register, 1994b). 

Habitats used by young razorback suckers have not been fully described because of the low 

number of young fish present in the basin. However, most studies indicate that the larvae prefer 

shallow, littoral zones for a few weeks after hatching, then disperse to deeper water areas. 

Laboratory studies indicated that in a riverine environment, the larvae enter stream drift and are 

transported downstream (Federal Register, 1994b). 

Thirty seven of 52 (71 percent) of the razorback suckers collected in one study were captured in 

two abandoned gravel pits near Grand Junction, Colorado (USFWS and Reclamation, 1982). The 

three habitats in which razorback suckers were captured most frequently were gravel pits, 

backwaters, and runs with the majority being gravel pits and backwater habitats typically with 

velocities near zero and a silt substrate. The study indicated that adult razorback suckers exhibited 

a preference for depths of 2.5 to 6.8 feet and flow conditions at or near 0.0 feet per second. 

The razorback sucker has displayed a degree of versatility in its ability to survive and spawn in 

different habitats. However, razorback sucker populations continue to decline and are considered 

28 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

below the survival level (Federal Register, 1993). Cumulative environmental impacts from 

interactions with non-native fish, high winter flows, reduced high spring flows, seasonal changes 

in river temperatures, and lack of inundated shorelines and bottom lands are factors that potentially 

limit the survival, successful reproduction, and recruitment of this species. Because there has been 

little or no recruitment of young to the adult population, special consideration is given to habitats 

required for reproduction and recruitment (Federal Register, 1994b). 

Consequences of the Proposed Action 

The minor depletions of 516 acre-feet/year resulting from the proposed action would not affect the 

razorback sucker or its designated critical habitat. The improved water quality in the Colorado 

River resulting from the proposed action may beneficially affect their designated critical habitat and 

therefore the species. 

Recommended Mitigation Measures 

Mitigation measures that might affect the razorback sucker are not recommended; however, 

improved water quality, which is the primary goal of the long term operation of the Unit, should 

benefit the species. 

Summary of Project Impacts 

The long term operation of the Unit would result in minor water depletions. However, these 

depletions should not affect the razorback sucker and should be offset by improvements in water 

quality. In addition, proposed changes in the operation of McPhee Reservoir should mitigate the 

affects of minor water depletions that would result from the long term operation of the Unit. Chronic 

low flows from McPhee Dam especially during the summer and other dry periods would be avoided 

which would benefit the razorback sucker. 

SOUTHWEST RIVER OTTER 

(Lutra canadensis sonorae) 

Status, Distribution, and Abundance 

The southwest river otter was previously listed by the Service as a category 2 candidate species 

and listed by the State of Colorado as endangered. Due to recent changes in the classification of 

category species as documented in this report, the southwest river otter is no longer listed as a 

candidate species. 

River otter were believed to be banished from Colorado earlier in this century. River otter were 

reintroduced to the Dolores River Basin in 1988 and are currently thriving. River otters thriving in 

29 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

the Dolores River today were introduced from populations from several states outside the 

Southwestern United States and it is highly unlikely that any rivers otters that inhabit the Dolores 

River is Lutra canadensis sonora (Beck, 1996). The State of Colorado, however, applies the State 

Endangered status to all populations of otters that have been introduced throughout the state. 

Life Requisites 

Food habitat studies of river otter in the Dolores River show that crayfish constitute a major portion 

of their diet. Typically, otter consume the most easily caught prey available which is crayfish in the 

Dolores River. In winter months, otter prey extensively on channel catfish and carp in the lower 

Dolores River. 

Consequences of the Proposed Action 

Improved water quality will result from the long term operation of the Unit. Improved water quality 

should benefit the populations of fish and crustaceans in the river which are the primary food base 

for river otters. 

Recommended Conservation Measures 

Proposed modifications in the operation of McPhee Reservoir should enhance riverflows of the 

Dolores River and improve the habitat of the river otter. 

Summarv of Project Impacts 

Long term operation of the Unit will result in minor water depletions to the Dolores River. It is highly 

unlikely that the State endangered southwest river otter inhabits the Dolores River. River otters 

in the Dolores River are reintroductions from other sections of the United States. However, 

improvements in water quality and potential increase in waterflows due to modifications in the 

operation of McPhee Dam will benefit any river otters that presently inhabit the Dolores River. 

SOUTHWESTERN WILLOW FLYCATCHER 

(Empidonax trai/lii extimus) 

Formal classification of the southwestern willow flycatcher as a federally-listed endangered species 

became effective March 29, 1995 (Federal Register, 1995). Prior to issuance of the formal 

designation, the Service had proposed listing as endangered with critical habitat (Federal Register 

1993a); however, at the current time, designation of critical habitat has been deferred pending 

evaluation of public comments and receipt of additional biological data. None of the land identified 

as being under consideration for inclusion as critical habitat in the 1993 proposed rule was located 

30 
1,448 acre-foot water depletion associated with the Unit's operation. 

However, further testing since 1989 resulted in alteration of brine 

removal and disposal methods and; hence, a change in the project as 

consulted on in 1989. Additionally, the razorback sucker (Xyrauchen 

texanus) has been federally listed, critical habitat for the endangered 

fishes has been designated and the amount of water depleted has been 

reduced. All of these changes necessitated reinitiation of formal 

section 7 consultation. 

PROJECT DESCRIPTION 

2 

The Paradox Valley Unit Project is located in T. 47 N., R. 18 W., 

sections 3, 4, 9, 16, 19, 20, 21, and 30 near Bedrock, Montrose County, 

Colorado. The facility's purpose is to remove salt laden brine water as 

part of the Salinity Control Project in the Colorado River Basin. This 

will be accomplished by intercepting and injecting the brine water into 

a 16,000 foot deep well which enters porous Mississippian and 

Precambrian rock formations. Removal of the brine water and water used 

at the Unit will result in a 516 acre-foot depletion to the Dolores 

River. 

During original construction, 24 brine water collection wells were 

installed; however, subsequent testing revealed that only 10 wells were 

needed for adequate brine removal. The 10 wells are located in sections 

9 and 16 on the east side of the Dolores River. An additional 

unconnected well will be kept available for possible future use but the 

other 13 wells will be or have been plugged or abandoned. In addition 

to the production wells, 68 groundwater testing wells have been 

installed to monitor water table levels, determine fresh and brine water 

interaction, and to determine brine water movement. 

The brine from the 10 production wells will be piped to a central 

surface treatment facility residing on 1.5 acres in section 16. The 

treatment :acili ty will f2.l ter t:he brine water and pump it into t~No 

25,000 gallon storage tanks. The water will then pass through a second 

filter and continue through a pipeline to the injection facility located 

on 6.5 acres in section 30. 

The injection facility consists of a building to house controls and 

injection pumps. A water treatment plant with associated storage tanks 

and ponds and a Well Annulus Monitoring System are also located on the 

6.5 acre site. One of the two 25,000 gallon storage tanks will be used 

to store the brine water •.;hile the other will be a backup and used 

during maintenance of the other tank. Fresh water from the Dolores 

River in section 20 is pumped to the operating tank to dilute the brine 

and control calcium sulfate precipitation. The fresh water also will be 

filtered through equipment, storage tanks, a flocculation pond, and a 

backwash pond to provide the facility's service water. The WAMS system 

consists of a pump and electronic monitoring system that is used to 

maintain pressure in the injection well. 

The 70 percent brine water mixture will be pumped through a 5~-inch 

diameter injection tube to a perforated liner that extends through the 

injection zone, which starts at approximately 14,000 feet below the 

surface. The brine water will migrate through the porous rock 
formations which will ac~ as a closed system reservo1r preventing 

escapement of the brine into surface waters. 

BASIS FOR BIOLOGICAL OPINION 

3 

This biological opinion addresses an average annual depletion of 

approximately 516 acre-feet from Dolores River in the Upper Colorado 

River Basin. Water depletions in the Upper Basin have been recognized 

as a major source of impact to endangered fish species. Continued water 

withdrawal has res~ricted the ability of the Colorado River system to 

produce flow conditions required by various life stages of the fishes. 

Critical habitat has been designated for the Colorado squawfish, 

humpback chub, bony~ail, and razorback sucker within the 100-year 

floodplain in portions of their historic range (59 F.R. 13374). 

Destruction or adverse modifica~ion of critical habitat is defined in 

50 CFR 402.02 as a direct or i~direc~ alteration that appreciably 

diminishes the value of critical habitat for both the survival and 

recovery of a listed species. :n considering the biological basis for 

designating critical habitat, ~he Service focused on the primary 

physical and biological elements that are essential to the conservation 

of the species without consideration of land or water ownership or 

management. The Service has identified water, physical habitat, and 

biological environment as the primary constituent elements. This 

includes a quantity of water of sufficient quality that is delivered to 

a specific location in accordance with a hydrologic regime that is 

required for the particular life stage for each species. water 

depletions reduce the ability of the river system to provide the 

required water quantity and hydrologic regime necessary for recovery of 

the fishes. The physical habitat includes areas of the Colorado River 

system that are inhabited or potentially habitable for use in spawning 

and feeding, as a nursery, or serve as corridors between these areas. 

In addition, oxbows, backwaters, and other areas in the 100-year 

floodplain, when i~undated, provide access to spawning, nursery, 

feeding, and reari~g habitats. 

BIOLOGICAL BACKGROUND 

Colorado Sguawfish 

The Colorado squawfish evolved as the main predator in the Colorado 

River system. The diet of Colorado squawfish longer than 3 or 4 inches 

consists almost en~irely of other fishes (Vanicek and Kramer 1969) . The 

Colorado squawfish is the largest cyprinid fish (minnow family) native 

to North America and, during predevelopment times, may have grown as 

large as 6 feet ~n length and weighed nearly 100 pounds (Behnke and 

Benson 1983). These large fish may have been 25-50 years of age. 

Based on early fish collection records, archaeological finds, and other 

observations, the Colorado squawfish was once found •hroughout warmwater 

reaches of the entire Colorado River Basin, including reaches of the 

upper Colorado River and its major tributaries, the Green River and its 

major tributaries, and the Gila River system in Arizona (Seethaler 

1978). Colorado squawfish were apparently never found in colder, 

headwater areas. Seethaler (1978) indicates that the species was 
abundanc in suitable habitat chroughou~ the entire Colorado River basin 

prior c~ the 1850's. ~istorically, Colorado squawfish have been 

collecced in the upper Colorado River as far upstream as Parachute 

Creek, Colorado (Kidd 1977). The Dolores River historically provided 

habitat for the Colorado squawfish at least up to the Paradox Valley 

(Seechaler 1978). 

4 

A marked decline in Colorado squawfish populations can be closely 

correlated with the construc~ion of darns and reservoirs between the 

1930's and the 1960's, introduction of nonnative fishes, and removal of 

water from the Colorado River system. Behnke and Benson (1983) 

summarized the decline of the natural ecosystem. They pointed out that 

darns, impoundments, and water use practices are probably the major 

reasons for dras~ically modified natural river flows and channel 

characreristics in the Colorado River Basin. Darns on the main stern have 

essenrially segmented the river system, blocking Colorado squawfish 

spawning migrations and drascically changing river characteristics, 

especially flows and ternperarures. In addition, major changes in 

species composition have occurred due to the introduction of nonnative 

fishes, many of which have thrived as a result of changes in the natural 

riverine system (i.e., flow and temperature regimes). The decline of 

endemic Colorado River fishes seems to be at least partially related to 

competition or other behavioral interactions with nonnative species, 

which have perhaps been exacerbated by alterations in the natural 

fluvial environment. 

The Colorado squawfish currently occupies about 1,030 river miles in the 

Colorado River system (25 percent of its original range) and is 

presenrly found only in the Upper Basin above Glen Canyon Darn. It 

inhabits about 350 miles of the main stern Green River from its mouth to 

the mouth of the Yampa River. Its range also extends 160 miles up the 

Yampa River and 104 miles up the White River, the two major tributaries 

of the Green River. :n the main stern Colorado River, it is currently 

found from Lake Powell extending about 201 miles upstream to Palisade, 

Colorado (Tyus er al. :982), and in the lower 60 miles of the Gunnison 

River, a tributary to rhe main stern Colorado River (Burdick pers. cornrn. 

1995). Possibly due t~ Uranium mill tailing contamination in the last 

40 years the Dolores River currently only harbors Colorado squawfish in 

the lower couple miles above its confluence with the Colorado River 

(Valdez et al. 1992). 

Critical Habitat 

Critical habitat has been designated within the 100-year floodplain of 

the Colorado squawfish's historical range in the following sec~ions of 

the Upper Basin (59 F.R. 13374). 

Colorado. Moffat c:mnry. The Yampa River and its 100-year 

floodplain from t~e State Highway 394 bridge in T. 6 N., ~- 91 W., 

section 1 (6th Principal Meridian) to the confluence with the Green 

River in T. 7 N., ~- 103 w., section 28 (6th Principal Meridian). 

Utah. Uintah. Carbon. Grand. Emery. Wayne. and San Juan Counties; 

and Colorado, Moffat County. The Green River and its 100-year 

floodplain from r~e confluence with the Yampa River in T. 7 N., 
R. 103 W., section 28 (6th Principal Meridian) to the confluence 

with t~e Colorado River in T. 30 S., R. 19 E., section 7 (Salt Lake 

Meridian) . 

Colorado. Rio Blanco County; and Utah. Uintah County. The White 

River and its 100-year floodplain from Rio Blanco Lake Dam in 

T. 1 N., R. 96 w., section 6 (6th Principal Meridian) to the 

confluence with the Green River in T. 9 S., R. 20 E., section 4 

(Salt Lake Meridian). 

Colorado. Delta and Mesa C0unties. The Gunnison River and its 

100-year floodplain from the confluence with the Uncompahgre River 

in T. 15 s., R. 96 w., section 11 (6th Principal Meridian) to the 

confluence with the Colorado River in T. 1 S., R. 1 W., section 22 

(Ute Meridian) . 

Colprado. Mesa and Garfield Counties; and Utah. Grand. San Juan. 

Wayne. and Garfjeld Counties. The Colorado River and its 100-year 

floodplain from the Coloraao River Bridge at exit 90 north off 

Interstate 70 in T. 6 s., R. 93 W., section 16 (6th Principal 

Meridian) to North Wash, including the Dirty Devil arm of Lake 

Powell up to the full pool elevation, in T. 33 S., R. 14 E., 

section 29 (Salt Lake Meridian). 

New Mexicp. San Juan County; and Utah. San Juan County. The San 

Juan River and its 100-year floodplain from the State Route 371 

Bridge in T. 29 N., R. 13 w., section 17 (New Mexico Meridian) to 

Neskahai Canyon in the San Juan arm of Lake Powell in T. 41 s., 

R. 11 E., section 26 (Salt Lake Meridian) up to the full pool 

elevation. 

Biolpgy 

The life-history phases that appear to be most critical for the Colorado 

squawfish include spawning, egg fertilization, and development of larvae 

through the first year of life. These phases of Colorado squawfish 

development are tied closely to specific habitat requirements. Natural 

spawning of Colorado squawfish is initiated on the descending limb of 

the annual hydrograph as water temperatures approach 20 ·c. Spawning, 

both in the hatchery and in the field, generally occurs in a 2-month 

timeframe between July 1 and September 1, although high flow water years 

may suppress river temperatures and extend spawning in the natural 

system into September. Conversely, during low flow years when the water 

warms earlier, spawning may occur in late June. 

Temperature also has an effect on egg development and hatching. In the 

laboratory, egg mortality was 100 percent in a controlled test at 13 •c. 

At 16 •C to 18 •c, development of the egg is slightly retarded, but 

hatching success and survival of larvae was higher. At 20 •c to 26 •c, 

development and survival through the larval stage was up to 59 percent 

(Hamman 1981). Juvenile temperature preference tests showed that 

preferred temperatures ranged from 21.9 •c to 27.6 •C. The most 

preferred temperature for juveniles and adults was estimated to be 

24.6 •C. ':'emperatures near 24 'C are also needed for optimal development 

and growth of young (Miller et al. 1982}. 

5 
6 

Only two Colorado squawfish confirmed spawning sites, as defined in the 

Colorado Squawfish Recovery Plan, have been located in the Basin: river 

mile 16.5 of ~~e Yampa River and river mile 156.6 of the Green River. 

These areas have the common characteristics of coarse cobble or boulder 

substrates forming rapids or riffles associated with deeper pools or 

eddies. It is believed that a stable, clean substrate is necessary for 

spawning and ~~cubation. Substrates are swept clean of finer sediments 

by high flows scouring the bed prior to the spawning period. 

O'Brien (1984) studied the hydraulic and sediment transport dynamics of 

the cobble bar within the Yampa River spawning site and duplicated some 

of its characteristics in a laboratory flume study. Based on field 

observations, he reported: 

"On the rising limb of the hydrograph, sands are deposited in 

the cobble interstices. These sands are interchanged between 

the bed and the suspended zone for discharges less than 

bankfull. Depending on the supply-capacity relationship, 

either deposition or scour could be occurring. ~hen the 

cobbles move, the sand, of course, is washed from the 

interstices and may be completely removed from around the 

cobbles. Rearrangement of the cobbles will result in more 

stability of the armor layer. On the falling limb, the armor 

layer becomes a trap for sands until finally, the sand 

reservoir is again filled. Without cobble movement, sand will 

be scoured only to a depth of one-half to one median cobble 

diameter below the cobble bed surface." 

In the flume experiments, the sand level was observed approximately 

0.50 to 1 cobble diameter below the surface of the cobble bed, which 

compared to field observations of sand depth at approximately 0.50 to 

1 median cobble diameter. O'Brien reported a cobble size range of 

50-100 mrn with a median size of 75 mrn at the spawning site. ~ilhous 

(1982) proposes discharges of approximately 0.50 of that required to 

initiate cobble movement will be capable of extracting sands and fines 

from the cobble substrate. Thus, after the supply of sand diminishes, 

flows of suff~cient magnitude and duration are required to scour the 

cobble bed i~ preparation for spawning and incubation. 

Although the location of spawning areas in the Colorado River is not 

well defined, the presence of larvae downstream of the Walker Wildlife 

Area, in the ~oma to Black Rocks reach and near the confluence of the 

Dolores River, demonstrates that spawning does occur. Osmundson and 

Kaeding (1989 and 1991) reported that water temperatures in the Colorado 

River were suitable for spawning in the Grand Junction area. In 1986, a 

year of high runoff, suitable temperatures for spawning (20 oc) occurred 

in the first week of August. In 1989, a year of low runoff, the mean 

temperature reached 20 oc during the last week of June. Miller et al. 

(1982) and ~~cher et al. (1986) demonstrated that Colorado squawfish 

often migrate considerable distances to spawn in the Green and Yampa 

Rivers, and similar movement has been noted in the main stern Colorado 

River. 

Miller et al. (1982) concluded from collections of larvae and 

young-of-year below known spawning sites that there is a downstream 
7 

drift of larval Colorado squawfish following hatching. Extensive 

studies in the Yampa and upper Green Rivers have demonstrated downstream 

distribution of young Colorado squawfish from known spawning areas 

(Archer er: al. 1986; Haynes et al. 1985). Miller et c..:.. \l982i also 

found that young-of-year Colorado squawfish, from late summer through 

fall, preferred natural backwater areas of zero velocir:y and less than 

1.5-foot depth over a silt substrate. Juvenile Colorado squawfish 

habitat preferences are similar to that of young-of-year fish, but they 

appear to be mobile and more tolerant of lotic conditions away from the 

sheltered backwater environment. 

Information on radio-tagged adult Colorado squawfish during fall 

suggests that fish seek out deepwater areas in the Colorado River 

(Miller et al. 1982), as do many other riverine species. River pools, 

runs, and other deep water areas, especially in upstream reaches, are 

importanT: winter habitats for Colorado squawfish. 

Very little informar:ion is available on the influence of turbidity on 

the endangered Colorado River fishes. It is assumed, however, that 

turbidity is important, particularly as it affects the interaction 

between introduced fishes and the endemic Colorado River fishes. 

Because these endemic fishes have evolved under natural conditions of 

high turbidity, it is concluded that the retention of these highly 

turbid conditions is an important factor for these endangered fishes. 

Reduction of turbidity may enable introduced species to gain a 

competitive edge which could further contribute to the decline of the 

endangered Colorado River fishes. 

Migration 

Radio-telemetry studies show upstream and downstream movement of adult 

Colorado squawfish in the main stem Colorado River. ~he most dramar:ic 

movement was exhibited by a fish implanted with a radio transmitter at 

Gypsum Cc.nyon in upper Lake Powell on April 5, 1982. ~he fish was 

contacted nexr: in the lower Cataract Canyon area on July 9, 1982. The 

next conr:act •.-~as made above the Black Rocks area of Ruby Canyon, some 

160 miles upstream. The movement was accomplished in 41 days and is 

believed to be related to spawning. At the end of September 1982, this 

fish was located in the Colorado River in the vicinity of Clifton, 

Colorado (river mile 178), nearly 200 river miles from its furthesr: 

documenr:ed downstream locaT:ion. 

Other radio-tagged fish in the Colorado River have not displayed such 

dramatic migratory behavior. Radio-telemetry studies conducted by the 

Colorado River Fishery Project from 1982-1989 (Miller et al. 1982: 

Archer et al. 1986; Osmundson and Kaeding 1989), which focused on 

upstream reaches of the Colorado River in and around the Grand Valley, 

provide r:he best indication of use of the 15-mile reach above the 

confluence of the Gunnison River at one time or another during the field 

season. Movement of these fish during a field season was generally 

limited to 25-30 miles. 

During 1986-1988, the Fishery Project radio telemetered 17 adult 

Colorado squawfish collected from the :i.5·-mile reach above r:he Gunn~.son 

River in June (Osmundson and Kaeding 1989) . The fish exhibited a 
diversity of localized movement ~~roughout the Grand Valley but spent a 

major part of time in the 15-mile reach. Two remained in the reach 

throughou~ the es~ima~ed spawning period. 

Spawning Activity 

A suspected prespawning aggregation of adult Colorado squawfish was 

observed by Fishery Project personnel at river mile 178.3 in the 

8 

15-mile reach above the Gunnison River confluence in mid-July 1982. In 

the first observation, ~hree radio-tagged fish were tracked to one 

riverine pool area, and nine adults at or near spawning condition were 

then captured there after limited net sampling efforts. The aggregation 

occurred a few days after mean daily water temperature had reached 20 oc 

and during a time when runoff flows were dropping off sharply. A second 

aggregation was noted at river mile 175.3, 12 days after the initial 

observation. Drifting trammel nets through an area occupied by two fish 

equipped with transmitters yielded an additional male Colorado squawfish 

in spawning condition. During this same time period, an adult female 

was captured near river mile 175 that weighed nearly 1 pound more than 

when previously captured a month earlier, suggesting the development of 

spawning (gravid) condition. 

Larval Occurrence 

Fishery Project studies included the routine sampling of the larval-fish 

community both within and downstream of the 15-rnile reach. During 

5 years of investigation, 70 larval squawfish were collected with 

fine-mesh hand nets from the two Colorado River reaches in the Grand 

Valley immediately upstream and downstream of its confluence with the 

Gunnison River. Although the sampling effort was similar in the two 

river reaches, 96 percent of the larval captures occurred downstream of 

the Gunnison River confluence (river miles 162-164). Only two 

(3 percent) of the larvae were collected from the upstream reach. These 

observations may indicate that ~ost fish were spawned i~ the downstream 

reach or that the larvae were deposited in the upstream reach and 

drifted downstream to the area where most of the captures were recorded. 

Postlarval Young-of-Year Occurrence 

No postlarval young-of-year Colorado squawfish greater than 25 mm total 

length were collected from above the Gunnison River confluence in a 

total of 57 samples collected in the fall of 1982-1986. However, a 

total of 62 Colorado squawfish were collected in an 18-mile reach below 

the confluence of the Gunnison River (54 samples) . The ~982-1984 catch 

rate of young-of-year Colorado squawfish in the 10-mile reach 

immediately downstream of the confluence of the Gunnison River 

(river miles 160-170) warranted classification of this reach as a 

"Young-of-Year Nursery Area" by the Basin Biology Subcommittee 

(U.S. Fish and Wildlife Service 1984). 

Nonspawning Adult Occurrence 

Osmundson and Kaeding (1989) reported that adult Colorado squawfish 

catch rates in the upstream 15-mile reach were twice as high as those in 

the adjacent downstream river reach. During 1986-1989 adults were most 
9 

abundant in a 1.3-~ile segment 'river ~iles 174.4-175.7) of the 15-mile 

reach during high ;;a~:er, ;:artic'..llarly in two gravel-pit ponds that were 

accessible during r.igh f2.~ws. chese fish may have moved into tr.ese 

ponds to feed and rest:, ~r they may have been at:tract:ed to t:he warm, 

productive environment:s rhat the ponds provided (pond temperatures were 

as much as 10.5 'C ·,;armer -:han the adjacent river) . Some of the 

squawfish captured =rom one pond were well tuberculated by June 3, when 

nearby river tempera~:ures were only 10 'C-13 'C (Kaeding, pers. comm.). 

It has been hypothesized by some investigators that thermal energy units 

above those provided in the mainstream are important to gonadal 

maturation. If this is true, then access to these sheltered off-channel 

pools may be very i~portant to successful spawning in the upper reaches 

of the Colorado River. Historically, bottomlands that routinely flooded 

during the spring r'..lnoff period would have provided these warm 

productive habitats; in recent 1ears, flooded gravel pits may have 

provided the only c~mparable habitat. 

Razorback Sucker 

The razorback sucker, an endemic species unique to the Colorado River 

Basin, was historically abundant: and widely distributed within warmwater 

reaches throughout -:he Colorado River Basin. Historically, razorback 

suckers were found in the main stem Colorado River and major tributaries 

in Arizona, California, Colorado, Nevada, New Mexico, Utah, Wyoming, and 

in Mexico (Ellis 1914; Minckley 1983). Bestgen (1990) reported that 

this species was once so numerous that it was commonly used as food by 

early settlers and, further, that commercially marketable quantities 

were caught in Arizona as recently as 1949. In the Upper Basin, 

razorback suckers ·.<ere reported in the Green River to be very abundant 

near Green River, ~tah, in the late 1800's (Jordan 1891). An account in 

Osmundson and Kaeding (1989) reported that residents living along the 

Colorado River near Clifton, Colorado, observed several thousand 

razorback suckers ~'..lring spring runoff in the 1930's and early 1940's. 

In the San Juan River drainage, Platania and Young (1989) relayed 

historical account:s of razorback suckers ascending the Animas River to 

Durango, Colorado, ~round the t:'..lrn of the century. 

A marked decline i~ populations of razorback suckers can be attributed 

to construction of dams and reservoirs, introduction of nonnative 

fishes, and removal of large quantities of water from the Colorado River 

system. Dams on the main stem Colorado River and its major tributaries 

have segmented the river system and drastically altered flows, 

temperatures, and channel geomorphology. Major changes in species 

composition have occurred due to the introduction of numerous nonnative 

fishes, many of which have thrived due to man-induced changes to the 

natural riverine system. 

The current distritution and abundance of the razorback sucker have been 

significantly reduced ttroughout: the Colorado River system AcAda 1987; 

McAda and Wydoski :980; :'iolden and Stalnaker 1975: ·~inckley c983; Marsh 

and Minckley 1989; ~yus :987). The only substantial population of 

razorback suckers rema:r.ing, made up entirely of old adults (!1cCarthy 

and Minckley 1987:, is f:und in cake Mohave; however, they do not appear 

to be successfully recruiting. While limited numbers of razorback 
10 

suckers persis~ in other ~:=ations in the Lower Colorado Riverr they are 

considered rare or inciden~al and may be continuing ~o decline. 

In the Upper Basinr above Glen Canyon Dam, razorback suckers are found 

in limi~ed numbers in both :entic and lotic environmen~s. The largest 

population of razorback suckers in the Upper Basin is found in the upper 

Green River and lower Yampa River (Tyus 1987). Lanigan and Tyus (1989) 

estimated that from 758 to 1,138 razorback suckers inhabit the upper 

Green River. In the Colorado River, most razorback suckers occur in the 

Grand Valley area near Grand Junction, Colorado; however, they are 

increasingly rare. Osmundson and Kaeding (1991) report that the number 

of razorback sucker captures in the Grand Junction area has declined 

dramatically since 1974. 

Razorback suckers are in i~~inent danger of extirpation in the wild. 

The specific causes of this species' concinued decline are largely 

unknown at this time. As Eestgen (1990) pointed out: 

''Reasons for decline o~ most native fishes in the Colorado 

River Basin have been attributed to habitat loss due to 

construction of mainstream dams and subsequent interruption or 

alteration of natural :low and physio-chemical regimes, 

inundation of river reaches by reservoirs, channelization, 

water quality degradation, introduction of nonnative fish 

species and resulting compe~itive interactions or predation, 

and other man-induced disturbances (Miller 1961, Joseph et al. 

1977, Behnke and Benson 1983, Carlson and Muth 1989, Tyus and 

Karp 1989) . These factors are almost certainly not mutually 

exclusive, therefore it is often difficult to determine exact 

cause and effect relationships." 

The virtual absence of any recruitment suggests a combination of 

biological, physical, and/cr chemical factors that may be affec~ing the 

survival and recruitment c= early life stages of razorback suckers. 

Within the Upper Basin, recovery efforts endorsed by the Recovery 

Implementation Program include the capture and removal of razorback 

suckers from all known locacions for genetic analyses and development of 

discrete brood stocks if necessary. These measures have been undertaken 

to develop refugia populations of the razorback sucker :rom the same 

genetic parentage as their "ild counterparts such that, if these fish 

are genetically unique by subbasin or individual population, then 

separate stocks will be available for future augmentation. Such 

augmencation may be a necessary step to prevent the extinction of 

razorback suckers in the Upper Basin. 

Critical Habitat 

Critical habitat has been cesignated within the 100-year floodplain of 

the razorback sucker's hiscorical range in the following sections of the 

Upper Basin (59 F.R. l3374l. 

Colorado. Moffat Counc•r. 

floodplain from the mouth 

R. 98 W., section 23 (6th 

The Yampa River and its 100-year 

of Cross Mountain Canyon in T. 6 N., 

Principal Meridian) to the confluence 
with the Green River ~n T. - N., R. 103 W., sect~~n 23 

(6th Principal Meridian). 

11 

Utah. Uintah Ccuntv; and C: 1 orado, Moffat County. :he Green River 

and its 100-year floodplain from the confluence Wlth the Yampa 

River in T. 7 N., R. :03 W., section 28 (6th Principal Meridian) to 

Sand Wash in T. 11 s., R. :3 E., section 20 (6th Principal 

Meridian). 

Utah. Uiptah. Carbon. ~rand. ~rnery. Wayne. and San Juan Counties. 

The Green River and its 100-year floodplain from Sand Wash at river 

mile 96 at T. 11 S., R. :9 E., section 20 (6th Principal Meridian) 

to the confluence with the Colorado River in T. 30 s., R. 19 E., 

section 7 (6th Principal Meridian). 

Utah. Uintah County. The White River and its 100-year floodplain 

from the boundary of the Ointah and Ouray Indian Reservation at 

river mile 18 in T. 9 S., R. 22 E., section 21 (Salt Lake Meridian) 

to the confluence with t~e Green River in T. 9 s., R 20 E., 

section 4 (Salt Lake Meridian). 

Utah. Uintah County. The Duchesne River and its 100-year 

floodplain from river mile 2.5 in T. 4 S., R. 3 E., section 30 

(Salt Lake Meridian) to the confluence with the Green River in 

T. 5 s., R. 3 E., section S (Uintah Meridian). 

Colorado. Delta and Mesa Counties. The Gunnison River and its 

100-year floodplain from the confluence with the Uncompahgre River 

in T. 15 s., R. 96 W., section 11 (6th Principal Meridian) to 

Redlands Diversion Dam in T. 1 S., R. 1 w., section 27 (Ute 

Meridian). 

Colorado. Mesa and Garf;~ld Counties. The Colorado River and its 

100-year floodplain from Colorado River Bridge at exit 90 north off 

Interstate 70 in T. 6 S., R. 93 W., section 16 (6th Principal 

Meridian! to Westwater Canyon in T. 20 s., R. 25 E., section 12 

(Salt Lake Meridian) including the Gunnison River and its 100-year 

floodplain from the Redlands Diversion Dam in T. 1 s., R. 1 w., 

section 27 (Ute Meridian! to the confluence with the Colorado River 

in T. 1 s., R. 1 W., section 22 (Ute Meridian). 

Utah. Grand. San Juan. ~ayne. and Garfield Counties. The Colorado 

River and its 100-year =~oodplain from Westwater Canyon in 

T. 20 s., R. 25 E., section 12 (Salt Lake Meridian) to full pool 

elevation, upstream of North Wash, and including the Dirty Devil 

arm of Lake Powell in T. 33 S., R. 14 E., section 29 (Salt Lake 

Meridian) . 

New Mexico. san Juan County; and Utah. San Juan County. The San 

Juan River and its 100-year floodplain from tb.e r.catack Diversion 

in T. 29 N., R. 16 W., section 9 (New Mexico Meridian) to the full 

pool elevation at the ~outh of Neskahai Canyon on the s~n Juan arm 

of Lake Powell in T. 41 S., R. 11 E., section 26 (Salt Lake 

Meridian) . 
3iolc~v 

Speci=ic i~forrnation on biologic~l and physical habitat requirements of 

=he razorback sucker is very li~2~ed. 3ntil very recently, fisheries 

research investigations throughout the Upper Basin have focused on the 

three listed Colorado River f~shes, and data collected on the razorback 

sucker was largely coincident ~o ~hose studies. Localized extirpation 

of razorback suckers from some l~calities, coupled with the species' 

cont~nued decline in numbers and distribution, has prompted some 

research; however, details of its life history requirements, 

part~cularly in riverine enviror~.ents, are still not fully understood. 

In general, a natural hydrograph with a large spring peak, a gradually 

descending limb into early summer, and low stable flows through summer, 

fall, and winter are thought to create the best habitat conditions for 

endangered fishes while rnaintain~ng the integrity of the channel 

geomorphology. Prior to constr~ction of large main stem darns and the 

suppression of spring peak flows. low velocity, off-channel habitats 

(seasonally flooded bottornlands and shorelines) were commonly available 

throughout the Opper Basin ITyus and Karp 1989; Osmundson and 

12 

Kaeding 1991). The absence of t~ese seasonally flooded riverine 

habitats is believed to be a limiting factor in the successful 

recruitment of razorback suckers in their native environment (Tyus and 

Karp 1989; Osmundson and Kaeding 1991). Tyus (1987) and McAda and 

Wydoski (1980) reported springti~e aggregations of razorback suckers in 

off-channel impoundments and tributaries; such aggregations are believed 

to be associated with reproducti?e activities. Tyus and Karp (1990) and 

Osmundson and Kaeding (1991) reported off-channel habitats to be much 

warmer than the main stern river and that razorback suckers presumably 

moved to these areas for feeding, resting, sexual maturation, spawning, 

and other activities associated ~ith their reproductive cycle. While 

razorback suckers have never been directly observed spawning in turbid 

riverine environments within the Upper Basin, captures of ripe 

speci~ens, Qoth males and females, have been recorded (Valdez ec al. 

1982; McAda and Wydoski ~980; Tyus 1987; Osmundson and Kaeding 1989; 

Tyus and Karp 1989; Tyus and Karp 1990; Osmundson and Kaeding 1991; 

Platania 1990) in the Yampa, Green, Colorado, and San Juan Rivers. 

Sexually mature razorback suckers are generally collected on the 

ascending limb of the hydrograph from mid-April through June and are 

associated with coarse gravel substrates (depending on the specific 

location). 

Outs~de of the spawning season, adult razorback suckers occupy a variety 

of shoreline and main channel habitats including low runs, shallow to 

deep pools, backwaters, eddies, and other relatively slow velocity areas 

associated with sand substrates ITyus 1987; Tyus and Karp 1989; 

Osmundson and Kaeding 1989; Valdez and Masslich 1989; Osmundson and 

Kaed~ng 1991; Tyus and Karp 1990). 

Habi~at requirernen~s of young and juvenile razorback suckers in the wild 

are ~argely unknown, particularly in native riverine environments. Life 

stages, other than adults, have not been collected anywhere in the Upper 

Basin in recent t~mes. The last confirmed documentation of razorback 

sucker juvenile in the Upper Basin was a capture in the Colorado River 

near Moab, Utah (Taba et al. 1965). 
13 

The current ~ange of the razorback sucker in the Colorado River extends 

upstream to Rifle, C0lorado. ~ost razorDack suckers captured in the 

Grand Valley area have been loca~ed in flooded gravel-?it ponds adjacent 

to the river. However, Gsmundson and Kaeding (1989) documented 

razorback sucker :novemen1: in various river habitats in the Grand Valley 

area. Additional surveys since l988 have documented razorback suckers 

in riverside ponds as far upstream as river mile 235 near Rifle, 

Colorado (Burdick 1992). 

Humpback Chub 

Humpback chub generally do not make migrational movements in the upper 

Colorado River and tend to reside throughout the year within a limited 

reach of river. Humpback chub are found inhabiting narrow, deep canyon 

areas and are relatively restricted in distribution. They seldom leave 

their canyon habitat (U.S. fish and Wildlife Service 1982). While 

humpback chub are regularly found dispersed in the Green and Yampa 

Rivers, the only major populations of humpback chub known to exist in 

the Upper Basin are located in Black Rocks and Westwater Canyons on the 

Colorado River. 

Critical Habitat 

Critical habitat has been designated within the humpback chub's 

historical range in the following sections of the Upper Basin 

(59 F.R. 13374). 

Colorado, Moff"t Countv. The Yampa River from the boundary of 

Dinosaur National Monument in T. 6 N., R. 99 W., section 27 

(6th Principal Meridian) to the confluence with the Green River in 

T. 7 N., R. 103 W., section 28 (6th Principal Meridian). 

Utah. c:<ntah Cc:unty; and C:lorado. ~-!affat County. The Green River 

from the confl'-lence ••i th the Yampa River in T. 7 N., R. 103 W., 

section 28 (6th Principal Meridian) to the southern boundary of 

Dinosaur National Monument in T. 6 N., R. 24 E., section 30 (Salt 

Lake Meridian) . 

Utah, cintah and Grand Counties. The Green River (Desolation and 

Gray Canyons) from Sumner's Amphitheater in T. 12 S., R. 18 E., 

section 5 (Salt Lake Meridian) to Swasey's Rapid in T. 20 s., 

R. 16 E., section 3 (Salt ~ake Meridian). 

Utah. G~and County; and Colorado. Mesa County. The Colorado River 

from Black Rocks in T. 10 s., R. 104 W., section 25 (6th Principal 

Meridian) to fish ford in T. 21 S., R. 24 E., section 35 (Salt Lake 

Meridian) . 
Utah. ~arfield and San Juan Counties. The Colorado River from 

Brown Betty Rapid ~n T. 30 S., ~- 13 E., section 34 (Salt Lake 

Meridian) to Imperial Canyon in T. 31 S., 2. 17 E., section 28 

(Salt :ake Meridian) . 

Bonytail 

Little is known abou~ the biological requirements of the bonytail, as 

the species has drastically declined in numbers in the Upper Basin 

shortly after 1960. Until recen~ly, the service considered the species 

extirpated from the Upper Basin; however, a recently collected specimen 

which exhibits many bonytail characteristics could indica~e a small, 

extant population (Kaeding et al. 1986). It is thought that, should 

this species persist in the Colorado River, the preferred habitat would 

be in the larger river reaches. 

Cri~ical P2bitat 

Critical habitat has been designa~ed within the bonytail's historical 

range in the following sec~ions of the Upper Basin (59 F.R. 13374). 

Colorado. Moffat County. The Yampa River from the boundary of 

Dinosaur National Monument in T. 6 N., R. 99 W., section 27 

(6th Principal Meridian) to the confluence with the Green River in 

T. 7 N., R. 103 w., section 28 (6th Principal Meridian). 

Utah, ~'intah Countv; and Colorado. ~loffat County. The Green River 

from the confluence with the Yampa River in T. 7 N., R. 103 W., 

section 28 (6th Principal Meridian) to the boundary of Dinosaur 

National Monument ~n T. 6 N., R. 24 E., section 30 (Salt Lake 

Meridian). 

Utah. ~intah and Grand Coun~ies. The Green River (Desolation and 

Gray Canyons) from Sumner's Amphitheater (river mile 85) in 

14 

T. 12 ., R. 18 E., sec~ion 5 (Salt Lake Meridian) to Swasey's Rapid 

(river ~ile 12) in T. 20 s., R. 16 E., section 3 (Salt Lake 

Meridian) . 

Utah, ::=rand County; and Colorado. t1esa County. The Colorado River 

from Black Rocks in T. 10 s., R. 104 w., section 25 (6th Principal 

Meridian) to Fish Ford in T. 21 s., R. 24 E., section 35 (Salt Lake 

Meridian) . 

Utah, :::arfield and San .Juan Counties. The Colorado River from 

Brown Betty Rapid in T. 30 S., R. 18 E., section 34 (Salt Lake 

Meridian) to Imperial Canyon in T. 31 s., R. 17 E., section 28 

(Salt :ake Meridian). 

ENVIRONMENTAL BASELINE 

The envircr~enta1 baseline includes the past and present impacts of all 

Federal, State, and priva~e actions and other human activities in the 

action area; the anticipated impacts of all proposed Federal projects in 

the action area that have already undergone formal section 7 
15 

consultation; and -:he i~pacr. State or private actions contemporaneous 

with the consulta~~on process. 

=~ formulating t~~s opinion, ~~e Service considered adverse ana 

beneficial effecc.s likely to result from cumulative effec-cs of future 

State and private activities ~~at are reasonably certain to occur within 

the Project area, along with t~e direct and indirect effects of the 

Project and impacts from actions that are part of the environmental 

baseline (50 CFR .;02. 02 and 402.14 (g) (3)). 

The physical and =iological features that were the basis for designating 

the critical habitat for the endangered fishes are water, physical 

habitat, and biological environment. These primary constituent elements 

were determined necessary for survival and recovery of the endangered 

fishes in the Opper Colorado River Basin. The primary constituent 

element water is described as a quantity of sufficient quality and with 

a hydrologic regi~e that is required for each life stage. Physical 

habitat includes areas of the rlver that are inhabited or potentially 

habitable by endangered fishes for use in spawning, nursery, feeding, 

and rearing or corridors between these areas. Biological environment 

includes food supply, predation, and competition. 

Water Quantity 

The environmental baseline for water quantity includes all historical 

depletions in the Opper Basin, depletions resulting from projects which 

have previously undergone section 7 consultation, and depletions 

resulting from projects contemporaneous with this consultation. 

Water oualjty 

Some of the cont~"inants of concern within waters of the Opper Basin 

include heavy meLals, selenium, salts, PAHs, and pesticides. Selenium 

is of particular ~oncern because of its documented effects on fish (and 

wildlife) reproduction. Many chemical, physical, and biological factors 

affect the toxicity of environmental contaminants to biological 

organisms. Chemlcal and physical factors include contaminant type, 

chemical species ~r form, pH, Nater temperature, dissolved oxygen, 

hardness, salinitj, and multiple-chemical exposure (antagonism and 

synergism). Duration of exposure, quantity of contaminant, and exposure 

pathways from the environment to the organism also affect toxicity. 

Some trace elements are beneficial to organisms at low concentrations 

but may be toxic at higher concentrations. Biological and physiological 

factors affecting toxicity include species, age, sex, and health of the 

organism. 

Seleni~" concentrations can be elevated in areas where irrigation occurs 

on soils which are derived from or which overlie Opper Cretaceous marine 

sediments. Percolation of i~~igation water through these soils and 

sediments leaches selenium into receiving waters. Other sources of 

selenimn include powerplant fly ash and oil refineries. ,iater 

depletions, by reducing dilution effects, have increased the 

::oncentrati.,)ns of' seleni'lln and other contaminants. In 1995, Colorado's 

t1ater Quality Com:rol Commission reduced the chronic selenium standard 
16 

from 17 )la/L ':o 5 ug/L. ::"he Service recommended the level be lowered to 

2 )lg/L. 

?hysical Habicac 

Water depletions, by affeccing c~e quancity and timing of flows, have 

reduced the ability of the river cO create and maintain habitacs and 

have reduced the frequency and duration of availability of certain 

habitats. 

Habitat Formacion 

The formation of a variety of channel habitats, including gravel/cobble 

bars and substrates used by Colorado squawfish for spawning, is 

essential to ensure che availability of the range of habitats required 

by all endangered f~sh life scages to fulfill daily requiremencs 

(foraging, =esting, spawning, avoiding predation, etc.) under various 

flow conditions. ::"he number ana distribution of these channel habitats 

can be descr~bed as channel habicat complexity, diversicy, or 

heterogeneicy. Osmundson and Kaeding (1991) found thac adult Colorado 

squawfish in the Grand Valley prefer river segments with a complex 

morphometry over those that are simple. 

Some important habitats, such as inundated floodplain depressions used 

by razorback suckers for spawning, are located outside the channel. 

Floodplain depressions are principally derived from abandoned main 

channels, side-channels, backwacers, and meander cutoffs. 

The creation of complex channel habitat and the formacion and eventual 

abandonment of channel features from which floodplain depressions are 

formed occur primarily during spring runoff when flows are of sufficient 

size and duration to cause major changes in channel morphology through 

significant erosion and deposit~on of bed and bank materials. The 

reduction i~ the magnitude, duration, and frequency of high spring flows 

has slowed the rate at which channel morphology changes. Consequently, 

the creation of complex channel habitat and floodplain depressions has 

slowed. The placement of riprap and other bank stabilization measures 

and the construction of dikes and levees impede changes in channel 

morphology and contribute to the slowed creation of complex channel 

habitat. In addition, the conscruction of dikes and levees reduces 

existing channel habitat complexity by causing channelization of the 

river. Dikes and levees also isolate existing floodplain depressions 

from the channel during high flows. The slowed creation of complex 

channel habitats and new floodplain depressions, the reduction of 

existing channel habitat complexity, and the isolation of existing 

floodplain depressions have acted to reduce the quantity and quality of 

important habitat =or endangered fishes. 

Habitat Maintenance 

Backwaters, used by various life stages of endangered fish, are damaged 

by the deposition of fine sediments which reduces their depth and 

consequentl! their iuration and frequency of inundation. Gravel and 

cobble substrates, ~sed by squawfish for spawning, are damaged by the 

infiltration of fine sediments. The establishment of vegetation on 
17 

backwater sedimen"C.s and on bars further :::educes the value of these 

habitats for enda~gered fishes. ?1...1rthermore, higher flows are required 

to flush sediments from vege"C.ated backwa"C.ers than from unvegetated ones. 

Osmundson and Kaeding (1991) reported observations that, Jn the 15-mile 

reach during che drought years of 1988 t~ 1990, backwacers were filling 

in with silt and spring flows were not sufficien"C. to flush out the f~~e 

sedimenc. ~lso, chey reporced that tamarisk colonized sand and cobble 

bars. The lower frequency of high wacer years, therefore, decreases the 

frequency at which silt and sand is flushed from backwaters, fine 

sedimencs are flushed from gravel/cobble substrates, and vegecation is 

scoured from backwacers and bars. As a result, the frequency ac which 

these habitats are suitable for use by endangered fishes has decreased. 

Seasonal Habitat Availability 

summer (Augusc-October): Osmundson et al. (1995) reported that, in the 

15-mile reach, availability of habitats did not differ significantly 

between periods of moderace flows and low flows. Though absolute area 

of habitac decreases with declining flows, relative area or percenc 

composition of habitat types changes little. However, squawfish habitat 

use patterns did change. The fish used a greater variety of habitats 

during moderate flows than during low flows. During moderate flows, the 

fish used primarily backwacers, eddies, and pools. During low flows, 

the fish used slow and fast runs almosc exclusively. The change in 

habitat use without a corresponding change in relative habitat 

availability indicates that other factors also influence habitat 

selection. These factors could include changes in quality of physical 

habitat features such as diversity, depth, dissolved oxygen, etc., or 

changes in biotic interactions. Osmundson et al. (1995) interpreted the 

squawfish behavioral changes as reflective of suboptimal conditions; the 

behavioral changes demonstrate the ability of the species to modify 

their habitat use patterns to temporarily cope with adverse conditions 

and do not demonstrate habitat preferences under optimum conditions. 

Winter (November-March): Osmundson et al. (1995) reported that, in the 

15-mile reach, flows during the winter are usually moderate because no 

water is diverted for irrigation and because additional water is 

released through upstream dams to increase reservoir storage capacity in 

anticipation of spring runoff. The relative availability of slow runs 

and riffles during the winter was very similar to their availability 

during summer. As in the summer, backwacers, eddies, and pools were the 

preferred t:mes of habitat in the winter. However, whereas eddies were 

most preferred in summer, pools were mosc preferred in winter. Adult 

squawfish used fewer habitat types overall during winter than during 

summer. Although fast runs and riffles were used during the summer, 

they were not used during the winter. The colder water temperatures in 

winter which cause lower mecabolic rates may account for the avoidance 

of high velocity sites. Absolute area of pools increases as flows 

decrease and slow runs lose velocity. 3ecause Osmundson et al. (1995) 

did not sample low flows in the winter, they could not determine if 

pools would still be preferred in the winter at lower flows. 

Spring (Apri1-Jllly): Osmundson and Kaeding (1989) reported t!"lat 

squawfish use of low velocity habitats such as backwaters and flooded 

gravel pits is greacesc during the spring runoff. It is believed that 
18 

squawfish use these habitats during the runoff to escape the high 

velocity, =-·:;w temperat:.ure flows ·:Jf the main channel. Because 

backwaters, flooaed gravel pit:.s, and other l~w velocity habitats are 

considerably warmer than t~e main channel during ~~e runoff, ~hese 

habitats allow squawfish to extend their growing season substantially. 

The earlier warming of these habitats also may be important in enabling 

squawfish to reach spawning condition by the time flow and temperature 

in the main channel are optimum for spawning. Osmundson et al. (1995) 

reported that, in the 15-mile reach, the numbers of backwaters and 

flooded gravel pits increases with increasing spring flows. (Although 

the number of backwaters eventually decreases as increasing flows 

convert backwaters to sidechannels, the number of other low velocity 

habitats likely increases as increasing flows inundate additional 

bottomlands.} The decrease in the magnitude, duration, and frequency of 

high spring flows, then, decreases the quantity and the duration and 

frequency of availability of important low velocity, higher temperature 

habitat in the spring. ~his could be affecting squawfish growth and 

spawning success. 

Also, the quantity and frequency of availability of inundated floodplain 

depressions used by razorback suckers for spawning is dependent on the 

magnitude and frequency of spring flows necessary to inundate these 

areas. The decrease in the magnitude and frequency of spring flows 

necessary to inundate floodplain depressions is believed to be largely 

responsible for poor razorback sucker spawning success. 

Biological Snvironment 

Food supply, predation, and competition are important elements of the 

biological environment. Food supply is a function of nutrient supply 

and productivity, which could be limited by the presence of 

contaminants. The modification of flow regimes, · ..;ater temperatures, 

sediment levels, and other habitat conditions caused by water depletions 

has contributed to the establishment: ~£ nonnative fishes. ?redation and 

competition from nonnative fishes have been clearly implicated in the 

population reductions or elimination of native fishes in the Colorado 

River Basin (Dill 1944, Osmundson and Kaeding 1989, Behnke 1980, 

Joseph et al. 1977, Lanigan and Berry 1979, Minckley and Deacon 1968, 

Meffe 1985, Propst and Bestgen 1991, ~inne 1991, and others}. Data 

collected by Osmundson and Kaeding (1991) indicated that during low 

water years nonnative minnows capable of preying on or competing with 

larval endangered fishes greatly increased in numbers. 

Nonnative fishes compete with native fishes in several ways. The 

capacity of a particular area to support aquatic life is limited by 

physical habitat conditions. Increasing the number of species in an 

area usually results in a smaller population of ~ost species. The size 

of each species population is controlled by the ability of each life 

stage to compete for space and food resources and to avoid predation. 

Some nonnative fishes' life stages appear to have a greater ability to 

compete for space and food and to avoid predation in the existing 

altered habitat than do some native fishes' life stages. 

Nonnative fishes are often stocked in and enter =ivers from off-channel 

impoundments. The periodic introduction of these nonnative fishes into 
19 

a river allows them 1:..-: b~Jpass .2..:..r:ti tations to reproduc-c.ion, growth, or 

survival that they might encounr.er in the river. -::onsequently, 

populations of nonnative fishes ~n the river are enhanced. Sndangered 

and other native species in the river experience grea-c.er compe-c.ition and 

predation as a result. 

EFFECTS OF THE ACTION 

Water Ouantitv 

The Project would cause an average annual new depletion of 

516 acre-feet. 

Water Quality 

The Project's depletion would cause a proportionate decrease in dilution 

which in turn would cause a proportionace increase in heavy metal, 

selenium, salts, P.~s, pesticides, and other contaminant concentrations 

in the Colorado River. ~n ~~crease in contaminant concen-c.rations in the 

river would likely result in an increase in the bioaccumulation of these 

contaminants in the food chain which could adversely affect the 

endangered fishes, particularly the predatory Colorado squawfish. 

Selenium is of particular concern due to its effects on fish 

reproduction and its tendency to concentrate in low velocity areas that 

are important habitats for Colorado squawfish and razorback suckers. 

Physical Habitat 

High spring flows are very important for creating and maintaining 

complex channel geomorphology and suitable spawning substrates, creating 

and providing access to off-channel habitats, and possibly stimulating 

Colorado squawfish spawning migrations. Adequate summer and winter 

flows are important for providing a sufficient quantity of preferred 

habitats for a duration and at a frequency necessary to support all life 

stages of viable populations of all endangered fishes. To the extent 

that the Project will reduce flows, the ability of the river to provide 

these functions will be reduced. 

Biqlogical Environment 

The modification of flow regimes, water temperatures, sediment levels, 

and other habitat conditions caused by water depletions has contributed 

to the establishment of nonnative fishes. To the extent that it would 

reduce flows and contribute to further habitat alteration, the Project 

would contribute to an increase in nonnative fish populations. 

Endangered fishes would experience increased competition and predation 

as a result. 

Summary 

The Service has concluded that the depletion of water caused by the 

Paradox Valley Unit will impact the primary constituent elements 

necessary for t~e survival and recovery of endangered fishes in the 

Upper Basin. Without actions taken to offset impacts, further flow 

reductions are likely to jeopardize the continued existence of the 
20 

endangered fishes and adversely modify or destroy their critical 

habitat. ~he Dolores River curre~~ly contributes flows that benefit the 

e~dangered fishes in the C~lorado River and water quality has returned 

to levels suitable for the possibility of endangered fishes 

rein~roduction (Valdez et al. 1992) 

REASONABLE AND PRUDENT ALTERNATIVE 

Regulations (50 CFR 402.02) implementing section 7 of the Act define 

reasonable and prudent alternatives as alternative actions, identified 

during formal consultation, that: (1) can be implemented in a manner 

consisten~ with the intended purpose of the action; (2) can be 

implemented consistent with the scope of the action agency's legal 

authority and jurisdiction; (3) are economically and technologically 

feasible; and (4) that the Service believes would avoid the likelihood 

of jeopardizing the continued existence of listed species or would avoid 

~he destruction or adverse modif~ca~ion of critical habitat. 

3ackground 

on January 21-22, 1988, the Secretary of the Interior; the Governors of 

Wyoming, Colorado, and Utah; and the Administrator of the Western Area 

Power Administration were cosigners of a Cooperative Agreement to 

implement the "Recovery Implemen~ation Program for Endangered Fish 

Species in the Upper Colorado River Basin'' (U.S. Fish and Wildlife 

Service 1987). An objective of the Recovery Program was to recover the 

listed species while providing for new water development in the Upper 

Basin. 

In order to further define and clarify processes outlined in 

sections 4.1.5, 4.1.6, and 5.3.4 of the Recovery Program, a Section 7 

Agreemen~ and a Recovery Implementation Program Recovery Action Plan was 

developed (U.S. Fish and Wildlife Service 1993). The Agreement 

establishes a framework for conduc~ing all future section 7 

consultations on depletion impac~s related to new projects and all 

impacts associated with historic projects in the Upper Basin. 

Procedures outlined in the Agreement will be used to determine if 

sufficient progress is being accomplished in the recovery of the 

endangered fishes to enable the Recovery Program to serve as a 

reasonable and prudent alternative to avoid jeopardy. The Plan was 

finalized on October 15, 1993, and has been reviewed and updated 

annually. 

In accordance with the Agreement, the Service assesses the impacts of 

projects that require section 7 consultation and determine if progress 

toward recovery has been sufficient for the Recovery Program to serve as 

a reasonable and prudent alterna~ive. If sufficient progress is being 

achieved, biological opinions are written to identify activities and 

accomplishments of the Recovery Program that support it as a reasonable 

and prudent alterna~ive. ~f sufficient progress in the recovery of the 

endangered fishes has not been achieved by the Recovery Program, actions 

from the Plan are identified which must be completed to avoid jeopardy 

to the endangered fishes. For historic projects, these actions serve as 

the reasonable and prudent alternative as long as they are completed 

according to the schedule identified in the Plan. For new projects, 
21 

~hese actions serve as the reasonable and prudent alternative so long as 

~hey are completed before the inpact of the project occurs. 

=n determining if sufficient progress has been achieved, =he Service 

~onsiders: 'a) actions which result in a measurable population 

~esponse, a measurable improvement in habitat for ~he fishes, :egal 

protection of flows needed for recovery, or a reduction in the threat of 

immediate extinction; (b) status of fish populations; (c) adequacy of 

flows; and ld) magnitude of the project impact. :n addition, ~he 

Service considers support activities (funding, research, information and 

education, etc.) of the Recovery Program if they help achieve a 

measurable population response, a measurable improvement in habitat for 

the fishes, :egal protection of flows needed for recovery, or a 

reduction in the threat of immediate extinction. The Service evaluates 

progress separately for the Colorado River and Green River subbasins; 

however, it gives due consideration to progress throughout the Upper 

3asin in evaluating progress toward recovery. 

:n its A9ri~ 5, 1996, annual review of sufficient progress, the Serrice 

concluded that the Recovery Program has made sufficient progress to 

enable it to serve as the reasonable and prudent alternative for 

projects with an average annual depletion of less than 1,500 acre-feet. 

This was a reduction from the 3,000 acre-feet threshold that was set for 

1995. The Service identified five actions which must be completed 

before the threshold will be raised back to 3,000 acre-feet: 

1. Finalization and implementation of the nonnative fish 

stocking procedures. 

2. Granting of a decree by the water court that allows for 

release of water from Steamboat Lake for instream flow 

purposes and finalization of a contract to provide up to 

3,000 acre-feet of water from Steamboat Lake for the 

endangered fishes. 

3. Completion of a short-term agreement to supply and deliver 

up to 21,650 acre-feet of water from Ruedi Reservoir for 

enhancing instream flows in the 15-mile reach. 

4. Approval of an FY 1997 work plan to implement high 

priority nonnative fish control projects in Colorado and Utah. 

5. Develop and agree to the scope and objectives of a 

strategy for addressing recovery of the endangered fishes in 

the 15-mile reach of the Colorado River, including a process 

and schedule for completing the strategy in a timely manner. 

The following excerpts summarize portions of the Recovery Program chat 

address depletion impacts, section 7 consultation, and project proponent 

responsibilities: 

"All f•.1ture section 7 consultations completed after 

approval and implementation of this program 

(establishment of the Implementdtion Committee, 

provision of congressional funding, and initiation of 
the elemencsl will result in a one-time contribution 

to be paid to che Service by wacer project proponencs 

in che amounc of $10.00 per acre-foot based on the 

average annual depletion of the project . This 

figure will be adjusced annually for inflation (the 

current figure is $13.'1 per acre-foot] 

Concurrencly wich the ccmplecion of the Federal 

accion which initiated the consultation, e.g., 

.. issuance of a 404 permit, 10 percenc of the 

total contribution will be provided. The 

balance . . will be . . due ac the cime the 

construction commences . n 

22 

It is imporcant to note that these provisions of the Recovery Program 

were based on appropriate legal protection of the instream flow needs of 

the endangered Colorado River fishes. The Recovery Program further 

states: 

" . it ~s necessary ~o protect and manage 

sufficient habitat to supporc self-suscaining 

populations of these species. One way to accomplish 

this is to provide long term protection of the 

habitat by acquiring or appropriating water rights to 

ensure instream flows . Since this program 

sets in place a mechanism and a commitment to assure 

that the instream flows are protected under State 

law, the Service will consider these elements under 

section 7 ~onsultation as offsetting project 

depletion impacts." 

Thus, the Service has determined that depletion impacts, which the 

Service has consistently maintained are likely to jeopardize the listed 

fishes, can be offsec by (a) the water project proponent's one-ti~e 

contribution to the Recovery Program in the amount of $13.41 per 

acre-foot of the project's average annual depletion, (b) appropriace 

legal proteccion of instream flows pursuanc to State law, and 

(c) accomplishment of activities necessary to recover the endangered 

fishes as specified under the Plan. The Service believes it is 

essential that protection of instream flows proceed expeditiously, 

before significant additional water depletions occur. 

The Service has determined that, because the project's average annual 

new depletion of 516 acre-feet is below the current sufficient progress 

threshold of 1,500 acre-feet, the Recovery Program can serve as t~e 

reasonable and prudent alternative to avoid jeopardy to the Colorado 

squawfish, razorback sucker, humpback chub, and bonytail and can serve 

as the reasonable and prudent alternative to avoid destruction or 

adverse modificacion of critical habitat caused by the project's 

depletion. 

Additionally, the Paradox Valley Unit is a Bureau of Reclamation projecc 

and the Bureau has agreed to contribute $1.5 million annually tc ~he 

Recovery Program. Secause of this ongoing contribution and the 

commitment by the Bureau to operate Upper Colorado River Basin projects 

under its control to provide instream flows for the endangered fishes as 
23 

identified in the Recovery Program, no contribution for existing or 

future Bureau projec~s will be collec~ed as pare of the seccion 7 

consultation process. As a result, no contribution is necessary for the 

516 acre-foot deple~ion resulting from che opera~ion of the 2aradox 

Valley Unit. 

INCIDENTAL TAKE 

Section 9 of the Endangered Species Ace, as amended, prohibits any 

taking (harass, harm, pursue, hunc, shoot, wound, kill, trap, capture or 

collect, or attempc to engage in any such conduct) of listed species 

without a special exemption. Under the terms of section 7(b) (4) and 

section 7(0) (2), taking chat is inciden~al to and not intended as part 

of the agency action is not considered taking within the bounds of the 

Endangered Species Act, provided that such taking is in compliance with 

the incidencal take statement. 

The Service does not anticipate that the proposed action will result in 

any incidental take of the endangered =ishes. 

CONCLUSION 

This concludes the Service's biological opinion on the impacts of the 

proposed project. This opinion was based upon the information described 

herein. If new information becomes available, if a new species becomes 

listed, if incidental take occurs, if the total average annual amount of 

water depleted by this project changes, or if any other project element 

changes which alters the operation of the project from that which is 

described in your correspondence and which may affect any endangered or 

threatened species in a manner or to an extent not considered in this 

biological opinion (see 50 CFR 402.16), formal section 7 consultation 

should be reinitiated. 

Thank you for your cooperacion in the formulation of this biological 

opinion and your interes~ in conserving endangered species. 

~·~ ' .J ,- ••• 
24 

?.EFERENCES 

Archer, D.L., :-:.M. Tyus, and L.? .. Kaeding. :986. Colorado River fishes 

monitoring projec~. final ~epor~. ~.s. Fish and Wildlife Service, 

Colorado River Fishery Projec~, Lakewood. 64 pp. 

Behnke, R.J., and D.E. Benson. :983. Endangered and threatened fishes 

of the Upper Colorado River Basin. Ext. Serv. Bull. 503A, Colorado 

State University, Fort Collins. 38 pp. 

Bes~gen, K.R. ~990. Status Review of the Razorback Sucker, (Xyrauchen 

texanus). Larval Fish Laboratory #44. Colorado State University, 

Ft. Collins. 

Burdick, 3.D. 1992. A plan t~ evalua~e stocking to augment or restore 

razorback suckers in the ~pper Colorado River. U.S. Fish and 

Wildlife Service, Final Report, Grand Junction, Colorado. 56 pp. 

carlson, C.A., and R.T. Muth. :989. The Colorado River: lifeline of 

the American Southwes~. ?ages 220-239 ill D.P. Dodge, ed. 

Proceedings of the International Large River symposium. Canadian 

Special Publica~ion of Fisheries and Aquatic Sciences 106, ottawa. 

Ellis, N.M. l914. Fishes of Colorado. oniversity of Colorado Studies. 

Vol. 11 (1) . 

Hamman, R.L. 1981. Spawning and culture 

(Ptychocheilus lucius) in a raceway. 

River Fishery Project Final Repor~. 

of Colorado squawfish 

ln Miller et al. Colorado 

Haynes, C.M., R.T. Muth, and T.P. Nesler. 1985. Identification of 

habitat requirements and l~miting factors for Colorado squawfish 

and humpback chub. Final ?.eport:., Federal Aid in Fish and Wildlife 

Res~ora~~on, Project SE-3-4. Colorado Division of Wildlife, 

Denver. 52 pp. 

Holden, ?.B., and C.B. Stalnaker. 1975. Distribution and abundance of 

mainstream fishes of the middle and upper Colorado River basins, 

1967-1973. Transactions of the American Fisheries Society 

104 (2) :217-231. 

Jordan, J.S. 1891. Report of explorations in Colorado and Utah during 

the summer of 1889 with an account of the fishes found in each of 

the river basins examined. Bulletin of the United States Fish 

Commission 9:24. 

Joseph, ~.W., J.A. Sinning, R.J. Behnke, and P.B. Holden. 1977. An 

evaluaticn of the status, ~ife history, and habitat requirements of 

endangered and threatened fishes of the upper Colorado River 

system. ~.s. Fish and Wildlife Service, Office of Biological 

Services, Fort Collins, Col0r-ado, FWS/OBS 24, Part 2:183. 
25 

Kaeding, :.R., 3.D. 3urdick, ?.A. Schrader, and W.R. Noonan. :986. 

Recen~ capture cf a bonytail chub (Gila elegans) and observations 

on this nearly exrcinct: cyprinid f:::om the Colorado River. ,:opeia 

1986 (4): 1021-1023. 

Kaeding, :.R., and D.3. Osmundson. 1989. Biologically defensible flow 

recommendations for the maintenance and enhancement of Colorado 

squawfish habitat in the "C.5-mile" reach of the upper Colorado 

River during July, Auguste, and Seprcember. U.S. Fish and Wildlife 

Service, Grand C"uncrcion, Colorado. 169 pp. 

Kidd, G. 1977. An investigation of endangered and threatened fish 

upper Colorado River as related to Bureau of Reclamation 

Final Report, Bureau of Reclamation, Salt Lake City, 

species in 

Projecrcs. 

Utah. 36 pp. 

Lanigan, S.H., and H.M. Tyus. 1989. ?opulation size and status of the 

razorback sucker in the Green River basin, Utah and Colorado. 

North American C"ournal of Fisheries Managemenrc 9:1. 

Marsh, P.C., and W.L. Minckley. 1989. Observations on recruitment and 

ecology of razorback sucker: lower Colorado River, 

Arizona-California. Great Basin Naturalist 49(1) :71-78. 

McAda, C.W. 1987. StaLus of the razorback sucker (Xyrauchen texanus) 

in the Colorado River upstream from Lake Powell. Proceedings of 

the Desert Fishes Council 17(1985) :185. 

McAda, C.W., and R.S. Wydoski. 1980. The razorback sucker, (Xyrauchen 

texanus), in the upper Colorado River basin, 1974-76. U.S. Fish 

and Wildlife Service Technical ?aper 99. 50 pp. 

McCarthy, C.W., and W.L. Minckley. :987. Age estimation for razorback 

sucker (Pisces: Catosrcomidae) f:::om Lake Mohave, Arizona and Nevada. 

Journal Arizona-Nevada Academy of Science 21:87-97. 

Milhous, R.T. 1982. Effect of sediment transporrc and flow regulation 

on the ecology of gravel-bed rivers. Ill Hey, R.D., J.C. Bathwist, 

and C.R. Thorne, eds. Gravel-bed rivers. John Wiley and Sons, New 

York. 

Miller, ;.J.H., J.J. 'lalentine, D.L. Archer, H.M. Tyus, R.A. Valdez, and 

L.R. Kaeding. :982. Colorado River Fishery Project Final Report 

Summary. U.S. Fish and Wildlife service, Salt Lake City, Utah. 42 

pp. 

Miller, R.R. 1961. Man and the changing fish fauna of the American 

Southwesrc. Papers of the Michigan Academy of Science, Arts, and 

Letters 46:365-404. 

Minckley, W. L. 1983. Status of the razorback sucker, (Xyrauchen 

tex2!'.'JS) l~.bborct), ~n the 10wer C0lorado River basin. Southwestern 

Naturalist ?.812) :165-187. 
26 

O'Brien, ,;.s. 1984. :.983 Yampa River c~·bble reach raorphology 

inves-c.igation. ?inal ?_epor::. iJ. S. ?ish and Wildlife Service, 

Denver, Coloraao. J pp. 

Osmundson, D.B., and L.R . .:::aedir:.g. 1989. Studies of Colorado squawfish 

and razorback sucker ~se of the ''15-mile reach'' ~f the Upper 

Colorado River as par-c. of c8nservation measures for ~he Green 

Mount: a in and Ruedi Reservoir water sales. Final Report. U.s. Fish 

and Wildlife Service, Srand Junction, Colorado. 

Osmundson, D.B., and L.R. ~aeding. 1991. Flow recommendations for 

maintenance and enhancement of rare fish habitat in the 15-mile 

reach during October-June. ?inal Report. U.S. Fish and Wildlife 

Service, Grand Junc"C.~8n, Colorado. 

Platania, S.P. 1990. Biological summary of the 1987 to 1989 New 

Mexico-Utah i=~thyofaunal s~udy of the San Juan River. Unpublished 

report to the :·Iew Mexico Department:. of Game and Fish, Santa Fe, and 

the U.S. Bureau of Reclama1:~on, Salt Lake City, :Jtah, Cooperative 

Agreement 7-FC-40-05060. 

Platania, S.P., and D.A. Young. 1989. A Survey of the Icthyofauna of 

the San Juan and Animas Rivers from Archuleta and Cedar Hill 

(respectively) to their Confluence at Farmington, New Mexico. 

Department of Biology, Univeis~ty of New Mexico, Albuquerque. 

Seethaler, K. 1978. Life History and Ecology of the Colorado Squawfish 

(Ptychocheilus lucius) in the upper Colorado River basin. Thesis, 

Utah State University, Logan. 

Taba, S.S., J.R. Murphy, and H.H. Frost. 1965. Notes on the fishes of 

the Colorado P.i ver ::ear Moab, Utah. Proceedings of the Utah 

Academy of Sciences, ~rts, and Letters 42(2) :280-283. 

Tyus, H.M. 1987. Jistribution, reproduction, and habitat use of the 

razorback sucker in che Green River, Utah, 1979-1986. Transactions 

of the American Fisheries Society 116:111-116. 

Tyus, H.M., and C.~. Karp. 1989. Habitat Use and Streamflow Needs of 

Rare and Endangered :ishes, Yampa River, Colorado. U.S. Fish and 

Wildlife Serv~ce, Biology Report 89(14). 27 pp. 

Tyus, H.M., and C.A. Karp. 1990. Spawning and movemencs of razorback 

sucker, (Xyrauchen texanus), in the Green River basin of Colorado 

and Utah. Southwestern Naturalist 35. (In Press) 

Tyus, H.M., B.D. Eurdick, R.A. Valdez, C.M. Haynes, '::.A. Lytle, and C.R. 

Berry. 1982. Fishes of the Upper Colorado River Basin: 

Distribution, abundance and status. Pages 12-70 in Miller, :·l.H., 

H.M. Tyus and C.A. Carlson, eds. Fishes of the Upper Colorado 

River System: Present and Future. Western Division, American 

Fisheries Scc~ety, ~~thesda, Maryland. 
U.S. Fish and Wildlife Service. 1982. Colorado River fishery Project 

Final Repor~. Part! (42 ~p.), Part II (356 pp.), and Par~ III 

!342 pp.). ?repared for c~e U.S. Bureau of Reclamation, Salt Lake 

City, Utah. April 1982. 

27 

u.s. Fish and Wildlife Service. 1984. Rare and Endangered Colorado 

River Fishes Sensitive Areas: a Report to the Upper Colorado Eiver 

Basin Coordina~ion Committee by the Upper Basin Biological 

Subcommittee. 23 pp. 

u.s. Fish and Wildlife Service. 1987. Recovery Implemen~ation Program 

for Endangered Fish Species in the Upper Colorado River Basin. 

U.S. Fish and Wildlife Service, Denver, Colorado. 82 pp. 

u.s. Fish and Wildlife Service. 1993. Section 7 consultation, 

Sufficient Progress, and Historic Projects Agreement and Recovery 

Action Plan, Recovery Implementation Program for Endangered Fish 

Species in the Upper Colorado River Basin. U.S. Fish and Wildlife 

Service, Jenver, Colorado. 50 pp. 

Valdez, R.A., P.G. Mangan, R.P. Smith, and B.C. Nilson. 1982. Upper 

Colorado River investigation (Rifle, Colorado to Lake Powell, 

Utah). u.s. Fish and Wildlife Service and Bureau of Reclamation, 

Final Report, Part 2, Colorado River Fishery Project, Salt Lake 

City, Utah. 

Valdez, R.A., and W.J. Masslich. 

endangered fish-Green River. 

adult Colorado squawfish and 

BIO/WEST Inc., Logan, Utah. 

1989. Winter habitat study of 

Wintertime movement and habitat of 

razorback suckers. Report No. 136.2. 

178 pp. 

Valdez, R.A., W.J. Masslich, and A. Wasowicz. 1992. Dolores River 

native f:!.sh habitat suitability study (UDWR Contract ~lo. 90-2559), 

Report No. TR-272-02. 3IO/WEST Inc., Logan, Utah. lllpp. + 

appendix. 

Vanicek, C.D., and R.H. Kramer. 1969. Life history of the Colorado 

squawfish (Ptychocheilus lucius) and the Colorado chub (§.i..l.a 

robusta) in the Green River in Dinosaur National Monument, 1964-

1966. Transactions of the American Fisheries Society 98(2) :193. 
PARADOX VALLEY UNIT 

FINAL ENVIRONMENTAL ASSESSMENT 

Responses to Comments on the 

1996 Draft Supplemental Definite Plan Report 

and Environmental Assessment 

Appendix D 

Introduction 

Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

APPENDIX D 

Comment Letters and Responses 

In October 1996, the Paradox Valley Unit Draft Supplemental Definite Plan Report 

and Environmental Statement were distributed to the public. An announcement of 

its availability was sent to the media and copies were available for review at 

Reclamation's Durango Office and local libraries. The report accompanied by a 

letter inviting comment was also mailed to parties who had expressed interest. 

The following letters were received at Reclamation's Durango Office commenting on 

the draft report. Each letter is followed by a response to issues raised therein. 
WCS-CSeale 

ENV-6.00 

United States Department of the Interior 

BUREAU OF RECLAMATION 

Northern Division 

2764 CompaSI Drive 

PO Box 60340 

Grand Junction CO 81506-8785 

Upper Colorado Region 

Western Colorado Area Office 

OCT 2 3 1996 Southern Division 

835 E 2nd Avenue 

PO Box 640 

Durango CO 81302..()640 

Dear Interested Party: 

The Bureau of Reclamation invites you to comment on the enclosed Draft Supplemental Definite Plan 

Report' (DPR) and Environmental Assessment (EA) for the Paradox Valley Unit, Colorado. The 

report describes the disposal of natural brine inflow by deep well injection, an environmentally 

preferred solution supported by the Environmental Protection Agency. The Paradox Valley deepwell injection facility is located approximately 1.2 miles south of Bedrock, Colorado. 

Disposal of brine by an evaporation pond method was the plan of project development in 1979. 

Information gained later in proj~ct planning revealed that an alternative plan of injecting brine into 

deep wells described in the original DPR might result in less impact to the environment. Subsequent 

testing has proved that this method of brine disposal to be the preferred alternative. 

The EA evaluates the effects of operating the injection facility to reduce salt-loading in the Dolores 

River by intercepting and disposing of naturally occurring brine groundwater entering the river in the 

unit area. 

As the Dolores River crosses Paradox Valley, it picks up approximately 200,000 tons of salt that it 

contributes annually to the Colorado River. The deep injection well and associated brine well field 

facilities have the capability to reduce this salt contribution to the Dolores River by 50-70 percent. 

You may send your written comments on the Supplemental DPR and EA to the Bureau of 

Reclamation, Attention: Clarice Seale, PO Box 640, Durango, Colorado 81302-0640, or Fax 

(970) 385-6539. The deadline for comments is November 12, 1996. Copies of the original DPR and 

EA are available upon request. 

Enclosure 

.t.CTING fO~ Patrick J. Schumacher 

Southern Division Manager 

1 A Defmite Plan Report is a Bureau of Reclamation document prepared by the planning division to 

summarize the purpose, design and operation of a proposed project. 
Grand Junction, Colorado 

November 26 , 1 996 

Bureau of ReciGmGtion ;Attention: CIDrice SeDie 

P. 0. Box 640 

Durango, CO 61302-0640 

Re: Comments, Paradox Valley Untt Draft Supplement&! lf9f1iiita' 

Plan Report and Environmental Assessment. 

Figura 3, Page 20 of the Environmental Assessment SIUI..W.~_anru 

on page 20 U Is stated thDt "clearly, fluid pressure ctlang&s.-3re being manifested at depths shallower than originally pr-oposefh~ 

The text on page 20 goes on to say • Based upon the observation 

of Injection sequences six and seven, ReciGmatton constders-lt 

unlikely thGt fluid pressure changes would extend Gbove the -3 

km depth observed to data ... • Fl!lura 3 shows Injection 

sequences labeled 11 through 17. Are six" and ·seven· Included 

In 11 through 17 ?" I heart11y agree that continuous monitoring and accurafe determination of earthquake focal depths Is 

necessar:g. I think 1t may be likely that the fractures (faults?) 

wm conttnue to propagGte upwGrd. 

How confident Is BOR thGt the problem of Gnhydrite deposition in 

the Leadville wilt be solved by the 70/30 rat1o of brine to fresh 

water? Is this ratio derived from actual tests or is it 

Interpolated from the USGS test results at 60/20 ratio of brine 

to fresh water which showed little reduction in anhydrite praclpatton, and the results at 35/65 ratio of brine to fresh 

water, which showed suppressed anhydrite precipat1on. (Geochemical effects of deep-well ln1ect1on of theParadox 

Valley brine into Paleozoic carbonate rociC:s, Colorado, 

u. S. A., R. J. Rosenbauar, J. 1. Bischoff and V. K. Kharaka, App/letJ 

Geochemist'!/. Vol ;: pp 273-292_ 1992. ). Has additionol 

testing been done on Laadv111e rocks using 701 brine and 301 

fresh water? 

The Paradox Valley unit is essentially a "point source· of a h1rge volume of salt, ana efforts to eliminate or reduce the salt Input 

to the Dolores river should continue. I think it would be well to 

do an assessment of the probability of success at this time for 

the Proposed Action - Continue Operation of Test Injection Well 

versus the probability of success for the Raduim Evaporation 

Pond A1tarnat1Ye. My background Is In on and uranium 

exploration; In those businesses mora projects fall than are 

successful, becGuse subsurface geology is fraught with 

surprises and sometimes disappointments. I hope the Proposed Action works but policy makers in government, Gnd the general public should be made aware that sometimes a change of course 

may be needed, and that the Radium Evaporation Pond Alternative 

may have to be followed. 

Very truly yours, 

~()_~ 

Loyd A. Cerlson, Geologist 

1155 Grand Avenue 

Grand Junction, CO 61501 Phone 970-243-7257 
;::::..1 v v 

United States Department of the Interior 

Northern Division 

1764 Campau Drive 

PO Box 60340 

BUREAU OF RECLAMATION 

Upper Colorado Region 

Westem Colorado Area Office 

i1lJY C. u IC:::JO 

Southern Division 

RJS E 2nd Avenue 

PO Box 640 

Grand Junction CO 8\506-8785 Durango CO 81 ]02-0640 

WCS-SPowers 

ENV-6.00 

Mr. Loyd Carlson 

1155 Grand Avenue 

Grand Junction CO 81s 01 

Subject: Draft Supplement to Definite Plan Repon and Environmental Assessment, Paradox 

Valley Saliniry Control Unit. Colorado River Basin Salinity Control Project, 

Colorado 

Dear Mr. Carlson: 

As discussed witb Stan Powers of my staff, enclosed is additional information concerning tbe 

Paradox Unit injection well. If you have any questions or need additional information, please 

contact Stan at (970) 385-6555. 

Sincerely, 

~~Q.,i!R<m 

Pat Schurriiiet~r ,~o.cni'IG fOil. Southern Division Manager 

Enclosure 

SPowers:bjw: ll/20/96: 1 water/powers/carlette. wpd 
- FS 

FINAL REPORT 

DRILLING AND TESTING 

PHASE 

INJECTION TEST WELL NO. 1 

COLORADO RIVER BASIN SALINITY CONTROL PROJECT 

PARADOX VALLEY UNIT, COLORADO 

FENIX & SCISSON, INC. 

TULSA, OKLAHOMA 

BUREAU OF RECLAMATION 

CONTRACT NO. 6-CC-40-03250 
I 

I 

I 

1 

' 

I 

I 

I 

I 

I 

I 

~------·-- ···---~----------------- --------

FINAL COMPLETION REPORT 

KEDA JOB NO, 10-1189 

FEBRUARY, 1989 

PREPARED BY 

KEN E, DAVIS ASSOCIATES 

HOUSTON, TEXAS 

1 

I 

i 

-

__________________________ !(EN E. DAVIS 

A.SIIOC'JATBS 
I 

BUREAU OF RECLAnATION 

INJECTION TEST WELL NO. 1 

Clarence L. Harr 

Consulting Petroleum Geologist 

SW SE Sec. 30, T. 47 N., R. 18 W. 

Paradox Valley 

Montrose County, Colorado 

ELEVATION: K.B. 5028 Ft. G.L. 4996 Ft. 

TOTAL DEPTH: 16, 011l0 Ft. PRECAMBRIAN 

LOG TOPS 

DRILLED TRUE 

FORMATION DEPTH THICKNESS DATUM DEPTH fHICKNESS DATUM 

TRIASSIC 

Chinle Surf. 391 ?4996 Surf. 390 ?4996 

Moenkopi 391 749 ?4637 390 750 ?4638 

PERMIAN 

Cutler 1140 7190 ?3888 l141<l 7173 ~3888 

PENNSYLVANIAN 

u. Honaker Tra~l 8330 3710 -3302 8313 3693 -3285 

LaSal 12040 76 -7012 12006 76 -6978 

L. Honaker Tra~l 12116 268 -712188 1212182 268 -7054 

Paradox 12384 261 -7356 1235(/) 26121 -7322 

Hatch 12645 230 -7627 1261(/) 229 -7582 

Ismay 12875 265 -7847 12839 265 -7811 

1st Main Salt 13140 219 -8112 13104 218 -8(/)76 

2nd Main Salt 13535 69 -85(/)7 13497 69 -8469 

Base Salt 13604 -8576 13566 -8538 

Lower Paradox 136(1)4 127 -8576 13566 127 -8538 

.,n?.! j:lrnl'!riViPW rt r.rAnd Junction. Colo. 81503 303·24 1-5974 
/ 

FINAL GEOLOGICAL WELL REPORT 

Report Section _y_ 

BUREAU OF RECLAMATION 

INJECTION TEST WELL NO. 1 

PARADOX VALLEY 

30 - 47N - 18W 

MONTROSE COUNTY, COLORADO 

Paradox Valley Unit 

Salt Brine Injection Project 

Bedrock, Colorado 

BUREAU OF RECLAMATION 

Contract 4-CA-40-01660 

Project 10-760 

CLARENCE L. HARR 

Consulting Petroleum Geologist 

Clarence L. Harr 

Consulting Petroleum Geologist 
United States Department of the Interior 

a BUREAU OF RECLAMATION 

Upper Colorado Region 

... ~;m,.::~ Western Colorado Area Office 

.. ~.-';P> "'rd$e•~'\ '·. 

~ 

-~ ......... 

WCS-RPasquale 

ENV-6.00 

Northern Division 

2764 Compass Drive 

PO Box 60340 

Grand Junction CO 81506-8785 

Mr. Loyd A. Carlson, Geologist 

1155 Grand Avenue 

Grand Junction CO 81501 

1

1

!KI I 0 I::Jo i 

Southern Division 

835 E 2nd Avenue 

PO Box 640 

Dun.ngo CO 81302-0640 

Subject: Our Response to Your Letter of November 26, 1996, Commenting on the Draft 

Supplemental Definite Plan Report and Environmental Assessment, Paradox Valley 

Unit, CRSP, Colorado 

Dear Mr. Carlson: 

Please accept my apology for being so long in responding to your letter. 

In the first paragraph of your letter you note the confusion caused by a typographical error. The 

injection sequences are one through seven. The mention of sequences II through 17 is an error. 

We agree with your assessment of the value of continuous monitoring. The Environmental 

Protection Agency has concurred and language to that effect is included in the long-term 

operations permit. 

To address your concern that the fractures will continue to propagate upwards, we offer the 

following: 

Given a finite pressure increase at the bottom of the well, the fluid pressure increase at some 

distance from the bottom of the well must be less than that pressure increase and the farther a 

given point is from the well perforations the smaller the pressure perturbation will be. In other 

words, Delta Pressure is a strong function of distance. Further, as fluid is forced upwards it is 

doing work against gra'vitational body forces, this accounts for the preferential movement of fluid 

pressure changes laterally. I would argue there will be a fairly definite upper limit (vertically) to 

fluid pressure changes. Based upon the results of the first seven injection sequences we 

hypothesize that limit (assuming the injection pressures used in the future are equal to or less than 

those used previously) will likely be consistent with those shown in the DPR. One of the goals of 

further earthquake monitoring is to evaluate the validity of this assumption. This is why we try to 

have near real-time locations of the earthquakes. 
To address your concern as to whether or not the problem of anhydrite deposition in the Leadville 

(Formation) will be solved by the brine to a freshwater ratio, we offer the following: 

Based on the tests conducted by the U.S. Geological Survey and consultation with others 

experienced in this field, Reclamation has determined that the risk associated with the injection of 

a 70% brine solution is acceptable. However, we are currently conducting on site pilot test to 

determine the feasibility of using membrane nanofiltration technology to remove sulfate from the 

brine to allow injection without dilution. 

Should you have any other questions or want further information, please contact either 

Stan Powers or me at the letterhead address or by telephone at (970)385-6500. 

Ralph W. squale, Chief 

Land, Recreation, and Environmental Resources Group 

Southern Division 
2:; November 1996 

261 1 N. College Drive 

Durango. CO 81301 

\1s. Coobe Seale 

Durango Projects Office. 

Bureau of ReC-lamation 

P 0. Box640 

835 E. Second Avenue 

Durango, CO 31301 

Dear Ms. Seale, 

I write this letter to comment on the Colorado River Basin Salinitv Control Project. Paradox 

Valley Unit Draft Supplemental Definite Plan Report and Environmental Assessment released 

October !996. Please enter it into the public record. 

From all appearances, the Paradox Valley Project (PVU) shows indications ofbeing a welldesigned and essential component of Colorado River Basin desalinization and water qualitv 

control efforts. I, nonetheless, found one aspect of the financial analysis to be somewhat 

troubling. 

Both the PVU and Animas La-Piata Project (ALP) salinity value per ton have been indexed to 

1993 dollars using the consumer price index. The reported indexed annual value to society per 

ton of salt removed by the PVU is $334 and is based on direct benefits only ( page IV -II). The 

economic loss to society per ton of salt, projected to be introduced into the Colorado River Basin 

by ALP. is reported as $50 (page 30, ALP Economic and Financial Analyses Update, USDI. 

BOR. June 1995). Several outcomes appear to be possible due to this apparent discrepancv: 

(I) the PVU benefits, estimated at $42,752.000 per year tor removal of 128,000 tons of 

salt. are grossly inflated; 

(2) the annual estimated $7.901.000 cost of ALP salinity, at $50 per ton is underestimated 

by the huge amount of $284 per ton. 

(3) The PVU salinity reduction benefits are overestimated and the ALP salinity costs 

underestimated. 

For these reasons several questions linger. not so much about the appropriateness ofPVU, but 

about the use of numbers associated with reporting on the PVU as part of the public record. Is 

the project as sound on economic grounds as reported? If so, why are per unit salinity values so 

different between ALP and PVU? Since salinity production costs and salinity reduction benefits 

are essentially equivalent, and are calculated the same basin-wide using the same index., shouldn't 

the amounts be the same for each ton of salt regardless of whether the source is ALP runoff or 

PVU brine wells? If' outcome I' (above) is true, does BOR interest in the promotion of the 

environmentally and economically unsound ALP influence and confound the accurate reporting of 

economic facts on other projects? If' outcome 2' (above) is true, are the facts reported accurately 
in ALP documents? If'outcome 3' (above) is true. are anv facts related to salinity accurate? 

What are the facts in regard to this issue~ 

Respectfully. /1 - . !I ~vi\ J· -~~k J~ Hovez . 

/ 

_/ 

~'i_NZz .c.,K______ 

---" 
United States Department of the Interior 

BUREAU OF RECLAMATION 

WCS-KBeck 

TRA-0.00 

Northern Division 

2764 Compass Drive 

PO Box 6034() 

Grand Junction CO 81506-8785 

Mr. Mark J. Hovezak 

2611 North College Drive 

Durango CO 81301 

Dear Mr. Hovezak: 

Upper Colorado Region 

Western Colorado Area Office 

n,::~ 2 0 1996 

Southern Division 

835 E 2nd Avenue 

PO Box 640 

Durango CO 81302-0640 

Thank you for your letter of November 22, 1996. The question you raised on the discrepancy 

between the two reports is well taken. The wording needs to be changed to clarify the 

discussion on the salinity control program's annual costs and benefits. 

The annual benefits of salinity control are projected at approximately $340 for each ton of salt 

removed from the Colorado River system. The $340 is an estimate of the foregone 

downstream water user damage that would have occurred from the effects of high salt 

concentrations on agricultural conveyance facilities, crops and household water pipes and 

appliances (i.e., hot water heaters, water softeners, dishwashers, clothes washers, swamp 

coolers, etc.). The annual cost to construct facilities to reduce salt loading from the river, is 

approximately $50 per ton of salt removed. These two values (salinity costs and benefits) can 

be compared to the adage "pay me now or pay me later" when promoting proper automobile 

maintenance. In this instance, the construction of facilities to remove salinity (performing the 

timely and proper maintenance) will yield a net annual saving of approximately $290 per ton 

of salt removed ($340 - $50 = $290). Conversely, if the salt was not removed from the river, 

we could anticipate approximately $340 in related damage for each ton of salt carried 

downriver during the year (resulting from a lack of proper and timely maintenance). 

As the upper basin states develop their water supplies in accordance with the Colorado River 

Basin Compact, salinity concentrations will increase in the Colorado River. The Colorado 

River Basin Salinity Control Program has been enacted, in part, to ameliorate the negative 

aspects of this planned development. 

With regard to your question about why the salinity impact of the project's depletion is not 

included in the economic evaluation, it is a complicated state's rights issue. Without a 

question, Colorado's unused allocation of water from the Colorado River Compact is creating 
numerous economic benefits downstream and that developing this water would eliminate these 

bt~efits. Among many other possible benefits, these flows dilute saline sources in the lower 

Basin, produce power at several downstream dams, and the water is used by millions of 

California residents. However, the Basin States assen the right to develop their compact 

allocations and that any interim benefits caused by the lack of development of their allocation 

are only temporary. Therefore, the loss of these "temporary" benefits caused from a state's 

allocation flowing downriver are not included in the impacts or cost analysis. As you correctly 

identified, the impact of salt loading does not fall into this category and is included in the cost 

analysis. 

If you have any questions or need funher assistance, please call me at (970) 385-6558. 

KBeck: bjw: 12/20/96: 1 water/beck/havezak. wpd 

Sincerely, 

Ken Beck 

Project Team Leader 

Southern Division 
\1s. Cookie Seale 

Durango Projects Office 

Bureau of Reclamation 

P.O. Box 640 

Durango, CO 81301 

RE: Conunents on the Paradox Valley Unit Environmental Assessment 

Nov. 25, 1996 

Dear Ms. Seale: 

There are major discrepancies in how the Bureau of Reclamation treats doWI!strearif salihlty costs 

in the Colorado River Basin depending on what project the Bureau is trying to ju~iify. When. the Bureau is 

analyzing a salinity control project, downstream salinity costs (and therefore benefits from salt removal) · 

are quite high. When the Bureau is analyzing a water project which increases salinitv, downstre"!:' sali,nw 

costs mysteriously drop. 

In the Paradox Valley Unit Environmental Assessment, where the Bureau lsjustifying the ' 

construction of salinity control features, downstream salinity costs are quite high, $334 per ton of salt in 

1993 dollars. (Paradox Valley Unit Environmental Assessment, Oct. 1996, p. N-11.) If one were to use 

the $334 per ton figure in the Animas-La Plata Projeds Economic Analysis, the benefit/cost ratio would 

drop from 0.36:1.00 to 0.25: 1.00. Instead, since the Bureau is trying to justify the Animas-La Plata 

Project. which adds salinity to the Colorado River, the downstream costs of salinity suddenly drop to $50 

per ton in 1993 dollars. (Animas-La Plata Project, Economic and Financial Analyses Update, June 1995, 

p. 30.) The Bureau states. "The $50 unit cost was generally accepted by the peer reviewers as also being 

representative of the loss of economic value to downstream users." 

In addition, in its Animas-La Plata Project analysis, the Bureau incorporates only the cost of 

salinity caused by the concentrating effects of water consumption. The cost of the actual increase in salt 

loading by the project is neglected. Yet, in its benefit-cost analysis of the Dolores Project, the Bureau 

incorporates the costs of salt loading, because salinity control features are part of the project, and neglects 

the concentrating effects of water consumption. (Dolores Project, Final Supplement to Definite Plan 

Report, Dec. 1988, p. 66.) 

When is the Bureau going to give us a consistent analysis of downstream salinity costs and benefits 

created by its actions and stop manipulating numbers and method of analysis to justify its projects? Please 

include a copy of these conunents in your Animas-La Plata Project file. Thank you. 

~~·~~ ·. Jerry S;vingle "" ./ 

/ 

317 E. 5th Ave. ( 

Durango, CO 81301 

970-247-5797 

cc. Richard Sanderson- U.S. Environmental Protection Agency 

Katie McGinty - Council on Environmental Quality 
United States Department of the Interior 

BUREAU OF RECLAMATION 

WCS-KBeck 

TRA-0.00 

Northern Division 

2764 CompaSI Drive 

PO Box 60340 

Grand Junction CO 81506-8785 

Mr. Jerry Swingle 

317 E. 5th Ave. 

Durango CO 81301 

Dear Mr. Swingle: 

Upper Colorado Region 

Western Colorado Area Office 

Southern Division 

835 E 2nd Avenue 

PO Box 640 

Ours.ngoCO 81302~40 

Thank you for your letter of November 22, 1996. The question you raised on the discrepancy 

between the two reports is well taken. The wording needs to be changed to clarify the discussion 

on the saliniry control program's annual costs and benefits. 

The annual benefits of saliniry control are projected at approximately $340 for each ton of salt 

removed from the Colorado River system. The $340 is an estimate of the foregone downstream 

water user damage that would have occurred from the effects of high salt concentrations on 

agricultural conveyance facilities, crops and household water pipes and appliances (i.e., hot water 

heaters, water softeners, dishwashers, clothes washers, swamp coolers, etc.). The annual cost to 

construct facilities to reduce salt loading from the river is approximately $50 per ton of salt 

removed. These two values (saliniry costs and benefits) can be compared to the adage "pay me 

now or pay me later" when promoting proper automobile maintenance. In this instance, the 

construction of facilities to remove saliniry (performing the timely and proper maintenance) will 

yield a net annual saving of approximately $290 per ton of salt removed ($340- $50 = $290). 

Conversely, if the salt was not removed from the river, we could anticipate approximately $340 in 

related damage for each ton of salt carried downriver during the year (resulting from a lack of 

proper and timely maintenance). 

As the upper basin states develop their water supplies in accordance with the Colorado River Basin 

Compact, saliniry concentrations will increase in the Colorado River. The Colorado River Basin 

Saliniry Control Program has been enacted, in part, to ameliorate the negative aspects of this 

planned development. 

If you have any questions or need further assistance, please call me at (970) 385-6558. 

KBeck:bjw: 12/20/96: I waterlbeck/havezak. wpd 

Sincerely, 

Ken Beck 

Project Team Leader 

Southern Division 
GLEN A. MILLER 

2264 Willow Wood Road , 

Grand Junction, CO 81503 / 

Home 970-245-4347 Work 970-243-1642 

Bureau of Reclamation 

Att~: Clarice Seale 

P.O. Box 640 

Durango, CO 81302-0640 

Gentlemen: 

RE: Paradox Unit EA 

October, 1996 

,_)" ,r, -. .·•• . 

Thank you for the opportunity to comment on the Paradox EA. 

However, I respectfully must point out that the copy in the Mesa 

County Library was not made available to the public until November 

5, 1996 -- ONE WEEK is not adequate public time for review. My 

comments below are not comprehensive, but t~ey point out several 

obvious unsupported conclusionary statements and shortfalls in the 

EA. 

1. P. II- 2, Par. 3: The injection zone is described as 

Mississippian to Cambrian Age. Prior data on the bore hole 

indicates that Pre-Cambrian crystalline bedrock is also open 

to the well bore. Is this now part of the injection zone? 

2. P. II-2, Par. 4-5: The descriptions of and conclusions 

about the injection zone capacity and overlying barrier are 

somewhat misleading. There are no adec;'..late data to support 

the claim that long-term injection can occur without 

undesirable results. the supposed adequate salt barrier has 

already been breached by injected brine. This appears to be 

a violation of injection regulations. 

The ~~jection zone is not a "Black Hole,'' as it appears 

to have been assumed, but its •take" is dependent upon, (1) 

compression of native fluids that presently fill all available 

pore space, ( 2) deformation of the rock fabric, and (3) 

increased discharge of fluids from the injection zone. 

Apparently, little or nothing is known by the EA preparers of 

any of these conditions. All three factors are greatlj' 

complicated by the several faults (Fig. :I-3) in the vicinity. 

3. The data on hypocenters of earthquakes shown on Fig. II-3 

and Figs. 2-5 indicate that a large part of the 

"hydrofracturing• (one form of rock deformation noted above) 

is taking place progressively upward from the injection zone, 

probably along faults that are pre-exist~~g zones of weakness. 
Bureau of Reclamation 

November ~2, 1996 

Page 2 

The hypocenters, which reflect" ... where the fluid is f::.owing 

in the subsurface ... " ( P. 17) , appear to have migrated 

vertically upward to about 4,000 feet above the top of the 

injeccion zone. This is about 3,600-3,700 feet above t~e too 

of the salt barrier. Again, this appears to not be :.; 

compliance with injection regulations. The upward migration 

rate appears to be volume controlled, and computes at about 50 

feet of upward migration per acre-foot injected, or about 70 

feet per day at planned rates. Under constant injection at 

this rate, brine could appear at the surface in less than six 

months. 

If/when this occurs, the project will be shut down and we 

taxpayers will lose the entire investment. The conclusion en 

P. 23 (Par. 3) that ''Reclamation considers it unlikely fluid 

pressure changes would extend above the (-) 3 Km depth ... " is 

unsupported by data, flies in face of evidence and 

geohydrologic principles, and cannot be used to justify 

continuing this project on the same path. 

4. The assumption that diluting the brine with river water 

will solve the "Scale Formation" problem is fraught with 

uncertainty. Addressing this problem thusly is reminiscent of 

a pre-drilling USBR report on the project, which declared the 

injected brines and receiving zone brines to be "compatible!" 

The precipitation of calcium sulfate could be the ultimate 

limiting factor in the project, because the potential exists 

to precipitate several 100 tons per year in the injectio~ 

zone. 

5. Monitoring of critical hydrologic parameters is woefully 

lacking. Thus, there is no way to learn about cause-effect, 

and ~o "early-warning'' system to provide an alert to 

undesirable effects. 

A. Deep monitoring wells are needed, especially near 

the injection well ("nested" piezometers in several 

zones), to track the upward migration of fluids. 

The above-noted computed migration rates could be 

somewhat attenuated as more permeable near-surface 

zones are invaded. 

B. The boundary faults near the injection w~ll are in 

hydraulic connection with the river alluvium. Shallmv 

alluvial monitoring wells are needed to determine l: 

brine is entering the alluvium from the sub-surface. 
Bureau of Reclamation 

November 12, 1996 

Page 3 

C. The lateral extent of pressure rise could be 

expect:ed to be manifest as very small but: detectable 

land-surface deformation. A levelling net and/or tiltmeter system within the injection well fault block and 

onto the adjacent blocks should detect such deformation. 

Such deformation can also be measured in deep monitoring 

wells. 

In summary, the 

without a scient:ific 

adequate monitoring. 

evaporation concept 

alternative. 

Thank you. 

~rd~ 

Glen A. Miller 

GAM/an 

project should not continue to inject brine 

assessment of the entire system, and without 

In many respects, the original surface 

looks more and more desirable as an 

cc: Mr. Steve Miller, CWCB 

Ms. Ruth Hutchins 
Northern Division 

2764 Compua Drive 

PO Box 60340 

BUREAU OF RECLAMATION 

Upper Colorado Region 

Western Colorado Area Office 

MAY I 6 1997 Southern Division 

835 E 2nd Avenue 

PO Box 640 

Grand Junction CO 81506-8785 Durango CO 81302-0640 

WCS-RPasquale 

ENV-6.00 

Mr. Glen A. Miller 

2264 Willow Wood Road 

Grand Junction CO 81503 

Subject: Our Response to Your Letter ofNovember 12, 1996, Commenting on the Draft 

Supplemental Definite Plan Report and Environmental Assessment, Paradox Valley 

Unit, CRBSCP, Colorado 

Dear Mr. Miller: 

Please accept my apology for being so long in responding to your letter. 

The following addresses your comments in the order given in your letter. 

(1) As part of the well completion process, a portion of the injection well at depths within the 

Precambrian was perforated and could be expected to transmit injectate away from the well. The 

volume of fluid was expected to be low, however, based on the physical properties of the rocks in 

that interval. 

(2) It is not clear at this point how extensive the transmission of injectate above the salt layer has 

been. At least one source of confusion lies with the over simplified geological interpretation that 

was presented in the early evaluations at this site. (As with most other projects, as time has 

passed and additional data has been gathered a more complete and complex picture of the process 

has emerged.) The zone paralleling the Paradox Valley appears to be offset by a number of 

normal (down to the east, northeast) faults that trend parallel to the strike of the valley. The well 

is within this zone. The shallowest hypocenters are to the northwest of the well where the 

Leadville limestone is expected to be the shallowest. Further, the earthquake hypocenters are 

inferred to define a zone of elevated pore pressures that, combined with the existing state of stress 

at that point, lead to brittle failure. The actual location of the injectate is most likely much closer 

to the well than the furthest earthquake hypocenters. The injectate is believed to be displacing 

existing pore fluid ahead of the "brine front." This mechanism will be many orders of magnitude 

more important in "take" than will fluid compression. 
Given the number offaults inferred from the seismic reflection data and the earthquake data it is 

highly likely that at least some injectate has been pushed above the salt "barrier." This assertion 

could have been strongly defended if no seismic data, no earthquake data, and nothing but the 

pictorial representation of the geometry were available. That at least some brine will find a 

pathway upwards at least a short distance along preexisting fractures seems a certainty. (This is 

true of every injection well that has ever operated or been proposed.) The important question is, 

will there be a significant amount of injectate traveling upwards? At this time it appears there 

probably has been minimal upward migration. This contention is based on several observations: 

(A) The shallowest hypocenters occurred fairly early in injection sequence six; during the 

following sequence (the most prolonged), no further shallowing of hypocenters was observed. 

(B) To the west where the shallowest hypocenters were located, the Leadville Formation is 

much shallower than the depth inferred at the well. 

(C) Observations from injection over the past several months have shown no shallow events 

to the west. Almost all events observed recently have been to the east and relatively deep 

( -5 .4km). Again, if the interpretation of parallel normal faults is correct, the Leadville would 

be deeper in this area. 

(D) As discussed above, there will be a "spatial lag" between the earthquake hypocenters and 

the injectate. The hypocenters are inferred to outline an outer boundary for the position of the 

injectate. 

(3) As discussed above, recent observations (which have occurred over a period exceeding six 

months) have yielded a suggestion of deeper injectate transfer to the east, not continuing 

shallowing to the west. Simple physical calculations suggest the magnitude of upward 

migration of injectate must be limited. Given a finite bottom hole pressure, upward migration 

will be severely limited by gravity and frictional losses along the narrow fluid transfer paths. 

This is one of the key reasons for continued earthquake monitoring as a requirement of the 

permit for this site. The earthquake monitoring program will help us to continue to define the 

upper limits of fluid migration. 

( 4) This comment is a statement and no response is appropriate. 

(5) A specific statement is made in this question that the boundary faults near the well are in 

hydraulic connection with the river system. If this is the case, the members ofD8330 are 

unaware of any data that confirms or denies this statement. We would be very interested in 

any data that could prove this connection. 

General comment addressing your concern that there has not been adequate hydraulic modeling of 

the Unit: Envirocorp used a model based on limited data to evaluate the injection reservoir and 

predict the injection pressures and life of the well. Testing of this well has provided additional 

data necessary to conduct a sophisticated modeling effort. Modeling will be conducted as the 

need is further defined and funding allows. 
Should you have any other questions or want further information, please contact either 

Stan Powers or me at the letterhead address or by telephone at (970) 385-6500. If you wish to 

discuss the geological aspects in depth, you may contact Mr. Jon Ake at (303) 236-4195 

extension 276. 

l , 

~~asquale, Chief 

Land, Recreation, and Environmental Resources Group 

Southern Division 
STATE OF COLORADO 

Roy Romer. Governor 

DEPARTMENT OF NATURAL RESOURCES 

DIVISION OF WILDLIFE AN EQUAL OPPORTUNITT EMPLOYER 

John w. ,'.,..1umma. o.;rector 

6060 Broadway 

Denver. Colorado 8D216 

Telephone: !.303) 29-;--1192 

Bureau of Reclamation 

Southern Division 

P.O. Box 640 

Durango, CO 81302-0640 

Attention: Clarice Seale: 

: ~:• .... -z-..., __ .,~-4 

2300 South Townsend. 

Montrose, COi~~T-~ 

November 8 , 1911"6";,-.. ~ 

The Division of Wildlife has reviewed the October 1996 Draft 

Supplemental Definite Plan Report (DPR) and Environmental 

Assessment (EA) for the Paradox Valley Unit Salinity Control 

Project. The CDOW has found the documents to be complete and 

accurate regarding the items related to Wildlife, Fish and 

Wetland/Riparian Habitats. 

The Division concurs with the 

assessment. All of the biological 

proposed deep well injection project 

proposed conservation measures are 

Division of Wildlife. 

analysis and environmental 

impacts associated with the 

have been identified and the 

acceptable to the Colorado 

Thank ·:ou for giving us the opportunity to comment on this Draft 

Report. 

cc: B. Clark 

M. McLain 

Sincerely, 

·~~~· · f·-u /:. ~ c~ Tl-'. 

orwin Smith 

Wildlife Manager 

DEPARTMENT OF NATURAL RESOURCES. James S. Lochhead. Execut1ve Director 

WILD:...IFE COMMISSION. Arnold Salazar. Chairman • Hebecca L. Frank, Vice Chair • Mark LeValley. Secretary 

Louis F. Swift. Member • Jesse Langston Boyd, Jr.. Member 

William R. Hegberg, Member • John Stulp, Member • James R. Long, Member 
I~ REi'LY REFER TO 

ES/CO:BR 

65412-GJ 

To: 

From: 

Subject: 

United States Department of the Interior 

FISH .'.c-ID WILDLIFE SERVICE 

Ecological Services 

'X'em:rn Colorado Office. 

7G4 Horiron Drive, Somh Annex A 

Grmo junction, Colorado 8 t )OG-394G 

November 12, 1996 

Southern Division Manager, Bureau of Reclamation, \olerte';;C010rado 

Area Office, Southern Division, Durango, Colorado (Attn: Claric 

Seale) 1 

Acting Assistant Colorado Field Supervisor, Fish and \1 ld ifQ 

Service, Ecological Services, Grand Junction, Colorado · ,..t' 

Comments on Draft Supplemental Definite Plan Report, E 

Assessment, and Biological Assessment for the Colorado 

Salinity Control Project's Paradox Valley Unit, October 

J; 

i ronmenta 1 

iver Basin 

1996 

The Fish and Wildlife Service has reviewed the subject documents with 

accompanying cover letter dated October 23, 1996. The Paradox Valley Unit is 

intended to collect underground flows of salt rich brine water before the 

brine enters the Dolores River at Paradox Valley. The brine will be deposited 

in porous geologic formations several thousand feet down using injection 

wells. The Service realizes the need for reduction of Colorado River salt 

content to benefit Lower Colorado River Basin water users and possibly fish 

and wildlife. The Service allowed phases of the brine removal facility to be 

built in the 1970's and 1980's because of this realization. Consequently, the 

Service believes that continuing operation of the brine removal facility, as 

described in the preferred alternative, is acceptable with existing mitigation 

measures and future reasonable and prudent alternatives that will avoid 

jeopardy to endangered species. 

The Service previously formally consulted on the Paradox Valley Unit Project 

in 1977 and 1989. During the 1989 consultation, the Service concurred with 

''no effect" determinations for the black-footed ferret (Hustela nigripes), 

bald eagle (Haliaeetus leucocephalus), peregrine falcon (Falco peregrinus), 

and Echinocereus triglochidiatus var. inermis (Spineless hedgehog cactus) due 

to lack of direct affects on habitat, absence of the species during surveys, 

and mitigation measures incorporated into planning documents. The Service did 

not concur with "no effect" determinations for water depletion impacts to the 

Colorado squawfish (Ptychocheilus lucius), humpback chub (Gila cypha), or the 

bonytail (Gila elegans) and thus wrote a biological opinion. 

Changes in the project and delays in testing the injection wells resulted in 

delays in finalizing operation plans. During that time period additional 

species that could be impacted by the project were federally listed and 

critical habitat was designated for the endangered fishes. Consequently, 
Page 2 

further consultation was recommended by the Service during a 1994 inquiry by 

the Bureau of Reclamation. Subsequently, the Bureau requested species lists 

and prepared the current biological assessment. 

The current biological assessment does not discuss impacts on the spineless 

hedgehog cactus since it has been delisted. However, the biological 

assessment discusses impacts on the other species in the 1989 assessment as 

well as the Mexican spotted owl (Strix occidentalis Iucida), southwestern 

willow flycatcher (Empidonax trai77ii extimus), razorback sucker (Xyrauchen 

texanus), and the endangered fishes critical habitat. 

The Service concurs with your "no effect" determinations in the biological 

assessment for the peregrine falcon, bald eagle, black-footed ferret, Mexican 

spotted owl, and southwestern willow flycatcher. The Service concurs because 

important habitat and prey availability of the above species does not appear 

to be directly impacted by the facility or by the amount of water depleted by 

operations. 

The Service, once again, does not concur with your "no effect" determinations 

for the endangered fishes or their critical habitat. The Bureau used as 

rationale for their "no effect" determinations that they contribute money and 

participate in the Recovery Program for the Endangered Fishes in the Upper 

Colorado River Basin (Recovery Program), that the 516 acre-foot water 

depletion is a minor depletion and the program has achieved sufficient 

.progress to offset minor depletions, and that reoperation and releases out of 

McPhee Reservoir would offset those depletions. The Bureau also concluded 

that removal of the salt would improve water quality and create a beneficial 

affect to the endangered fishes and their critical habitat. 

Even though 516 acre-feet is considered a "minor" depletion under the Recovery 

Program and the Bureau participates in the Recovery Program, that does not 

mean that there is "no effect • to the endangered fishes or their critical 

habitat. Mitigation cannot be used to avoid a "may affect" determination 

unless that mitigation results in impacts that are beneficial, discountable, 

or insignificant. The Service has a policy that any water depletion should 

warrant a "may affect" determination for the endangered fishes and their 

critical habitat and does not believe that formal consultation can be avoided 

in this case. The Bureau also has a policy that their water depletions result 

in a "may affect" determination for the endangered fishes and their critical 

habitat (Steve McCall, BOR, pers. comm., 1996). 

Though the.Service believes that salt removal could be beneficial to the 

Colorado squawfish and the other endangered fishes, the beneficial affect is 

somewhat in question. In the biological assessment the Bureau referenced 

Seethaler (1978) who reported small squawfish being caught in the Dolores 

River as far up as Paradox Valley as late as 1962. The Bureau also referenced 

Valdez et al. (1992) in the biological assessment whom reported that salt 

levels become diluted once the San Miguel River enters the Dolores River. 

Valdez et al. (1992) also mention in their report that the Dolores River 

appears suitable for Colorado squawfish reintroduction and; therefore, they do 

not believe that the salt levels are a limiting factor. As the Bureau points 
Page 3 

out in the biological assessment, it is suspected that reduction of squawfish 

range in the Dolores River may be due to other factors such as past Uranium 

mining operations. Hence, the Colorado squawfish and the other endangered 

fishes may not be impacted by the salt loading. To say that removal of the 

salt will be a benefit to the endangered fishes beyond historical conditions 

will be difficult to conclude due to various anthropogenic effects in the last 

century. 

The Bureau is correct that because of their participation in the Recovery 

Program the Service does not apply the water depletion fee to the Bureau for 

"minor" depletions. However, neither the section 7 agreement nor the release 

of water make the depletion a "no effect" impact in the Service's (or 

Bureau's} opinion. The salt reduction could be beneficial, but that does not 

override the necessity for formal consultation due to the water depletion 

impacts. The Service believes that a "may affect" determination is warranted 

and recommends that the Bureau request, via memorandum, initiation of formal 

consultation. 

Literature Cited 

Seethaler, K.H. 1978. Life history and ecology of Colorado squawfish 

(Ptychocheilus lucius) in the upper Colorado River Basin. M.S. thesis. 

Utah State University, Logan, Utah. 

Valdez, R.A., W.J. Masslich, and A. Wasowicz. 1992. Dolores River Native 

fish habitat suitability study (UDWR Contract No. 90-2559}, Report No. 

TR-272-02. BID/WEST Inc., Logan, Utah. lllpp. +appendix. 

cc: BR, Grand Junction (Attn: Steve McCall} 

CDOW, Durango (Attn: Mike Japhet} 

FWS/ES, Golden 

FWS/ES, SLC (Attn: Reed Harris} 

T1Reland:saltdo~.mem:11129 
United States Department of the Inte~ior 

BUREAU OF RECLAMATION 5~ 

Northern Division 

2764 Compu• Drive 

PO Box 6034{) 

Grand Junction CO 81506·8785 

Upper Colorado Region 

Western Colorado Area Office 

DEC I 1 \996 

Southern Division 

835 E 2nd Avenue 

PO Box 640 

Durango CO 8 I J02-0640 

WCS-RPasquale 

ENV-7.00 

To: 

From: 

Subject: 

MEMORA.l'IDUM 

Acting Assistant Colorado Field Supervisor, Fish and Wildlife Service, 

Ecological Services, 764 Horizon Drive, South Annex A, Grand Junction CO 

Patrick J Schumacher /) I <"" /1 

Southern Division Manager~ . · ~ ...... - .. c..x____. 

Re-Initiation of Section 7 Consultation - Paradox Valley Unit Salinity Control Project, 

Colorado 

In accordance with your memorandum of November 12, 1996, we hereby request re-initiation of 

Section 7 Consultation on the Paradox Valley Unit Salinity Control Project. This is to be based 

on the October 1996 Draft Supplemental Definite Plan Report and Environmental Assessment 

(DPRIEA) which also includes our revised Biological Assessment. . We have received comments 

on the draft and are incorporating them. None of the comments received affect the Biological 

Assessment. 

The draft DPRIEA reflects the program change from the original DPR brine evaporation pond to 

deep well injection for brine disposal and the proposed change in status of the project from 

"experimental" to long-term operations. A draft EA on deep well injection, the Environmental 

Protection Agencys' preferred method, was circulated for comment in 1986 and deep well 

injection has been undergoing testing since 1991. This draft DPRIEA reflects the comments 

received on the 1986 draft EA as well as the program results to date. The chronology of previous 

coordination between Reclamation and the Service is also presented in the draft. Re-consultation 

is necessary because the Service does not concur with the Reclamation determination of no-effect 

for endangered fishes or their critical habitat. The conclusions of re-consultation are required 

before the draft can be finalized. 

Ralph Pasquale of my staff spoke with Terry Ireland and was assured that such consultation could 

be expedited. 

Your cooperation in this matter will be greatly appreciated. 

RPasquale:dmr: 12/13/96: [lregrp-pasquale-pdx.fws] 
HUTCHINS 

1574 L Road 

Fruita, Colorado 81521 

(970) 858-7363 

November 29, 1996 

Bureau of Reclamation 

Attn.: Clarice Seale 

P.O. Box640 

Durango, CO 81302-0640 

Re: Colorado River B.asin Salinity Control Project, Paradox Valley Unit r 

Draft Supplemental Definite Plan Report and Environmental Assessm~ 

October 1996 '-

Dear Clarice Seale: 

Please thank your office for extending the comment period from November 12 to November 29, 

1996. The extension is greatly appreciated. 

And thank you for allowing the public an opportunity to comment on the "Colorado River Basin 

Salinity Control Project's Paradox Valley Unit Draft Supplemental Definite Plan Report and 

Environmental Assessment, October 1996." 

Comments on the "Draft Supplement Definite Plan Report" are as follows: 

page 11-2, paragraph 3 

" ... The remaining 1. 789 feet of the bore is the injection zone. with Mississippianage Leadville limesrone serving as the primary injection formation and lower 

Devonian- and Cambrian-age formations serving as secondary injection zones." 

The original injection area stated on ihe well permit was limited from the top of the Leadville 

Limestone to the top of the Precambnan Gramte. Was the well permit modified 1n 1990 to Include 

the upper portions of the Precambrian Granite and Cambrian Granite at approximately 16,000 

feet below ground level? And why was the modification needed to extend the injection area? I 

would like to include the following reference clipped from the Williams Brothers Engineering 

Company's report: "Feasibility Study, Deep-Well Injection of Brine, Paradox Valley Unit, Apri113, 

1981." This study was prepared for the U.S. Department of the Interior, Water and Power 

Resources Service, Denver, Colorado. 

page 13-2, paragraph 4 

"Many residents of Colorado are aware that the Rocky Mountain Arsenal Disposal 

Well in Denver was implicated in the recorded increase of earth tremors in the 

Denver area in 1962-1965. The implication may be valid; however, it should be 

noted that this unusual well was drilled into non-porous, non-sedimentary 

Precambrian rocks. Disposal of the waste liquid into the fractures of the nonporous rock was artempted. Disposal wells typically are completed in porous, 
CLARICE SEALE, BUREAU OF RECLAMATION 

NOVEMBER 29, 1996 PAGE3 

If the construction of the Paradox Unit is considered completed, how is the money for this 

experimentation and potential development of a new technique going to be financed? 

Will a supplement to the Draft Supplemental Definite Plan Report be required? 

Was Paradox Valley Brine (PVB) initially injected into the well prior to the fresh water buffer 

injection? Did the precipitation of the initial PVB injection cause problems? 

Has an acidification procedure been used during this two-year testing period? If so, when and 

why was it needed? 

Why is this procedure omitted in a description of this report? 

page IV-1, paragraph 1, last sentence 

" ... Testing ofthe well is complete, with the results indicating that this method of 

brine disposal is physically and economically feasible." 

Does the Salinity Control Forum accept this statement: "that testing of the well is complete"? This 

report stated a new concept for sulphate removal will be attempted. 

Is testing deep-well injection as a viable way to remove salt still in a testing mode? Is more time 

needed before acceptance by the Forum? 

Is the Forum satisfied that all is well when a new method for removing sulfates is underway? 

Will the states agree to start the repayment contracts? 

If repayment is initiated and is to go for 50 to 1 DO years, can repayment stop if the project proves 

to be unworthy and not viable? 

page IV-2, paragraph 2 

'Water levels are checked in the wells during project operations and the data are 

used to determine what effect pumping the bn'ne production wells has on the water 

table, and how the fresh water and brine interact, and how the brine moves within 

the aquifer." 

Would have all pumped brine from the 10 wells being used actually reached the Dolores River? 

Has salt reduction to the Dolores River actually happened during the injection testing? 

Is it possible to measure a reduction in the river? 

Why is the information or an explanation not included in this report? 

page IV-4, paragraph 1 

" ... These 350-horsepower, alternating current ... " 
CLARICE SEALE, BUREAU OF RECLAMATION 

NOVEMBER 29, 1996 

page IV-1 0, paragraph 1 

PAGES 

... "The life of the Unit would be dependent upon the injection well reservoir 

capacity, which is unknown. When the present injection reservoir is filled, pumping 

pressures and related costs would increase." 

How does this statement match with that on page IV-5, paragraph 2? 

And how much attention did the BOR and EPA pay to the "U.S. Department of the Interior 

Geologic Survey: Evaluation of Hydrogeologic Aspects of Proposed Salinity Control Program in 

Paradox Valley, Colorado" by L.F. Konikow and M.S. Bedinger, Open-File Report 78-27, Denver, 

Colorado, 1978? An excerpt follows from page 20, paragraph 3: 

"Another option for handling the brine within Paradox Valley involves subsurface disposal 

through deep-well injection. An examination of the stratigraphic section for the area does 

not indicate a high probability of encountering a suitable reservoir rock that could sustain 

a long-term injection of a significant percentage of the discharge from the brine well field. 

A significant expenditure would be required simply to evaluate and test the physical 

feasibility of this option. If it were physically feasible, its implementation would then require 

high initial design and construction costs, and possibly also high annual maintenance and 

operating costs. If high-pressure injection is required, consideration must also be given 

to possible geologic hazards, such as induced earthquake activity or upward migration of 

the injection brine along existing faults, fractures, or abandoned deep wells." 

page V-3, paragraph 1 

''The second injection well would be drilled at the s1ce of an abandoned oil well, 

causing the same environmental effect as was caused by drilling the first well. The 

injection well would be drilled to Mississippian-Age Leadville Umestone as the 

primary injection zone and would be similar to the first well in construction." 

Williams Brothers Engineering Company report: "Feasibility Study Deep-Well Injection of Brine, 

Paradox Valley Unit" dated April 13, 1981, on page 1-1, Section 1: "Executive 

Summary-Conclusions" advised just that for the initial test well-using an abandoned oil well. 

Why did not the BOR follow this suggestion in 1986 when drilling started? Is the current well a 

non-performing wildcat well which should be abandoned? A "dry hole" so to speak? 

The price for drilling two wells as outlined on page V-3, Table V-1, is interesting. 

The BOR has reported to Congress over the years that the Paradox Unit is anticipated to cost 

$94.4 million. Proposal of a second well added to the first is estimated at $94,757,016.00. Did 

the figure of $94.4 million presented to Congress anticipate drilling of another well in addition to 

the test well? 

Why did the BOR not follow the original recommendation of Williams Brothers and use the old oil 

well? 
CLARICE SEALE, BUREAU OF RECLAMATION 

NOVEMBER 29, 1996 PAGE? 

I would suggest that the BOR go to Congress for additional funding for the needed new 

developments, that the Salinity Control Forum not accept the project as construction completed, 

and that testing under the proposed O&M program (not construction), not be acceptable. The 

project is not a tried and true project. The process has been trial and error. 

Thank you for this comment period. My current indisposition has not allowed me to use my typing 

service. I will fax this to you today, November 29, 1996, and hopefully have this typed for your 

permanent records. 

Sincerely, 

Ruth P. Hutchins 
United States Department of the Interior 

BUREAU OF RECLAMATION 

WCS-CSeale 

ENV-6.00 

Northern Division 

2764 Compass Drive 

PO Box 6034Q 

Grand Junction CO 81506-8785 

Ruth Hutchins' Family 

1574 L Road 

Fruita CO 81521 

Upper Colorado Region 

Western Colorado Area Office 

MAY 2 8 1997 

Southern Division 

835 E 2nd A venue 

PO Box 640 

Dunngo CO 81302-0640 

Subject: Comments from Ruth Hutchins, Paradox Valley Unit Draft Supplemental Definite 

Plan Report and Environmental Assessment, Paradox Valley Unit, Colorado River 

Basin Salinity Control Project, Colorado 

Dear Family Members: 

The Bureau of Reclamation received a letter from Ruth Hutchins, now deceased, commenting 

on topics of interest to her in the above draft report issued last fall. To our regret, a response 

to her comprehensive questions did not reach her before her death. The following information 

is provided as a matter of interest to family and friends. 

Depth Intervals for Injection and 

Rationale of Perforations 

Several sections of the 1981 Williams Brothers Feasibility Study are cited and a question 

regarding observed and future upward migration of injectate is posed. Several of the 

statements taken from the Williams Brothers report are incorrect. That report has a number of 

inaccuracies and errors. 

All of the formations drilled below the Leadville limestone contained natural fractures and 

some formations showed a limited degree of primary porosity. The injection liner was 

perforated through these formations to take advantage of any porosity, either primary or 

secondary, which may be available in the injection well. 

Very little fluid (as manifested by pressure changes large enough to lead to micro earthquakes) 

appears to be injected into the Precambrian interval. The overwhelming majority of fluid 

appears to be entering the Leadville intervals. 

Upper Limit to Fluid Mi~:ration 

Given a finite pressure increase at the bottom of the well, the fluid pressure increase at some 
distance from the bottom of the well must be less than that pressure increase; and the greater 

distance a given point is from the well perforations, the smaller the pressure perturbation will 

be. In other words, Delta Pressure is a strong function of distance. Further, as fluid is forced 

upwards it is doing work against gravitational body forces, this accounts for the preferential 

movement of fluid pressure changes laterally. We believe there will be a fairly definite upper 

limit (vertically) to fluid pressure changes. Based upon the results of the first seven injection 

sequences, we hypothesize that limit (assuming the injection pressures used in the future are 

equal to or less than those used previously) will likely be consistent with those shown in the 

Definite Plan Report for the Paradox Valley Unit. One of the goals of continued earthquake 

monitoring is to evaluate the validity of this assumption. This is why we try to have near realtime locations of the earthquakes. 

Whether Anhydrite deposition in the Leadville (formation) will be solved 

by the brine to a freshwater ratio 

Based on tests conducted by the U.S. Geological Survey and consultation with others 

experienced in this field, Reclamation has determined that the risk associated with the injection 

of a 70% brine solution is acceptable. However, we are currently conducting an onsite pilot 

test to determine the feasibility of using membrane nanofiltration technology to remove sulfate 

from the brine to allow injection without dilution. 

Earthquakes of Ma~;nitude Zero 

It is possible to have earthquakes of magnitude zero (or even negative magnitudes). This is a 

function of attempting to make our magnitude scale (which is based upon signal duration) 

consistent with the popular "Richter Magnitude Scale." This measure of earthquake "size" 

was developed several decades ago in California using a certain standardized instrument. The 

scale was defined such that a magnitude three earthquake at a distance of 100 km would have a 

zero displacement on the standard instrument. That standard reference instrument was a very 

insensitive instrument by today's standards. As a result, when we look at very small 

earthquakes (often referred to as micro earthquakes) that are not felt using newer instruments, 

the computed magnitudes can be less than zero. 

We hope this answers Ms. Hutchins' questions. If further information is desired, please 

contact either Stan Powers or Ralph Pasquale at the letterhead address or by telephone at 

(970) 385-6500. 

~ Ralph Pasquale, Chie 

Land, Recreation & Environmental 

Resources Group 

Southern Division 

Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

in Colorado. The Colorado Division of Wildlife currently identifies the southwestern willow 

flycatcher as having an undetermined status. 

The southwestern willow flycatcher is one of five currently recognized subspecies of willow 

flycatchers in North America. All are neotropical migrants, wintering in Mexico, Central America, 

and perhaps northern South America (Tibbitts et al., 1994). The southwestern willow flycatcher's 

historic and current breeding range includes southern California, southern Nevada, southern Utah, 

Arizona, New Mexico, and western Texas. Southwestern Colorado (and the southern portions of 

Utah and Nevada) are believed to be the northernmost extent of its breeding range, although 

nesting records for southwestern Colorado are lacking (Federal Register, 1995a; Tibbitts et al., 

1994). Where nesting activity has been documented, the southwestern willow flycatcher arrives 

at its breeding habitats as early as mid- to late-May and may remain until mid-August depending 

on altitude, latitude, andre-nesting (Tibbitts et al., 1994). 

The Bureau of Land Management (BLM) conducted surveys for nesting willow flycatchers along 

the Dolores River both upstream and downstream of the Paradox Valley during spring 1994 

(Ferguson, 1995). No birds were found along surveyed reaches located close to project facilities, 

although a number of suitable habitat sites were identified and mapped. A possible unconfirmed 

sighting, at the mouth of La Sal Creek upstream of project facilities, was reported earlier in the 

1994 season, but was not revisited during the spring 1994 BLM survey effort. 

Investigations by the National Biological Service during the spring 1994 breeding period along the 

Animas, La Plata, and Mancos Rivers did not reveal the presence of southwestern willow 

flycatchers on the Mancos River (Sedwick, 1994). Willow flycatchers were detected at five sites 

all on the La Plata River. Survey results concluded that all individuals observed were migrants and 

nonterritorial except at one site where a breeding male was determined to be territorial, but no 

evidence of breeding was found. The investigator concluded, as a result of this survey, that very 

few willow flycatchers occur in southwestern Colorado on either of the drainages surveyed, either 

in migration or during the breeding season, and that limited breeding may occur, and is suspected, 

but could not be documented (Sedwick, 1994). 

These surveys-both of which were conducted along degraded river segments on the fringe of the 

subspecies' purported historic range -tend to suggest that utilization of similar marginal habitat 

in the vicinity of the project would be unlikely. Furthermore, given the uncertain northern limit of 

the breeding range and the general absence of confirmed breeding records and observed territorial 

behaviors in southwestern Colorado, it is likely that willow flycatchers observed in the Paradox 

Valley area are migrant northern subspecies (E.t. adastus, E. I. traillii, E.t. campestris) or hybrids 

in route to or from more northerly breeding areas rather than the less common southwestern 

subspecies. 

31 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Life Requisites 

The southwestern willow flycatcher is most frequently associated with riparian habitats along rivers, 

streams, or other wetlands, where dense growths of willows, seepwillow, arrowweed, button bush, 

or other native shrubs and medium-sized trees dominate-often with a scattered overstory of 

larger, mature cottonwoods (Federal Register, 1995a; Tibbitts et al., 1994). Although preferring 

these structurally diverse native associations, the southwest willow flycatcher is also known to 

utilize thickets dominated by tamarisk and Russian olive. (Tibbitts et al., 1994). 

Nest sites are well concealed in thickets of trees and shrubs approximately 4-7 m (13-23 ft) in 

height, with dense foliage from approximately 0-4 m (13ft} above ground and a high percentage 

of canopy cover. The diversity of plant species immediately surrounding the nest site can range 

from low to high and may be either even- or uneven-aged, but is usually dense and structurally 

homogeneous (Federal Register, 1995a). 

The southwestern willow flycatcher virtually always nests near surface water or saturated soil 

(Federal Register, 1995a). Typically, wet conditions (surface water or saturated soil) are adjacent 

to or underlie nest sites; however, a range of mesic conditions appears to be suitable for E.t. 

extimus nesting. Nest sites may be adjacent to active stream channels or may be located at 

abandoned channels or oxbows where riparian vegetation exists but little or no surface water is 

present. Some nest sites may have surface water early in the nesting season but dry significantly 

by mid-summer (late-June to early-July) (Tibbitts et al., 1994). 

Available information indicates that patches of suitable vegetation as small as 1.23 acres can 

support one or two nesting pairs (Federal Register, 1995a); however, patches composed of very 

narrow riparian zones, with large distances between patches and individual plants typically are not 

selected (Tibbitts et al., 1994). 

Stream gradient may also be an important determinant in the suitability of habitat. To date, no nest 

sites have been located along steep-gradient streams characterized by almost continuous riffles, 

rapids, falls, or other cataracts. This may be because higher-gradient streams tend to form 

narrower riparian corridors or are confined within narrow, scoured canyons (Tibbitts et al., 1994). 

Threats to the subspecies include brood parasitism by the brown-headed cowbird, replacement of 

native riparian vegetation by exotic tamarisk, livestock browsing and trampling, pesticide 

contamination, predation, and probable loss of winter habitat due to tropical deforestation (Federal 

Register, 1995a; Sedgwick, 1994; Tibbitts et al., 1994). 

The control of livestock and exotic vegetation in the riparian zone would be an important 

conservation measure for any willow flycatchers that might potentially inhabit the Paradox Valley. 

Proposed modifications in the operation of McPhee Reservoir which could enhance riparian zones 

along the Dolores River may also benefit the species. 

32 
Consequences of the Proposed Action 

Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Potential southwestern willow flycatcher habitat is present along the west bank of the Dolores River 

and along West Paradox Creek near its confluence with the river. Several acres of predominately 

tamarisk in fairly large patches is present along the river and its confluence with West Paradox 

Creek. This riparian zone is supported by the meandering and overflows of West Paradox Creek 

and good quality groundwater from West Paradox Valley. Pumping from the well field on the east 

side of the river would not impact this vegetation. All of the project's major facilities and structures 

are located on the east side of the river on previously disturbed upland sites-situated either well 

above or well away from the river floodplain. Implementation of the proposed action will not affect 

the southwestern willow flycatcher. 

Recommended Conservation Measures 

No conservation measures are recommended for the willow flycatcher as a result of this project. 

Summary of Project Impacts 

Minor water depletions of the Dolores River will occur. Proposed modifications in the operation of 

McPhee Reservoir should benefit potential riparian zones habitats of the southwestern willow 

flycatcher. Improved water quality resulting from the project should increase aquatic invertebrate 

populations and provide a better food base for potential willow flycatcher populations that may 

inhabit the area. 

33 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

LITERATURE CITED 

Bailey, Robert G. 12980. Description of the Ecoregions of the United States. United States 

Department of Agriculture, Miscellaneous Publication No. 1391. Ogden, Utah. 

Beck, T. 1996. Personal Communication, March 1996. Colorado Division of Wildlife, Dolores, 

Colorado. 

BoyleS. and S. Franklin. 1993a. Mexican spotted owl surveys in Colorado by all agencies and 

companies, 1990-1993. November, 1993. Colorado Division of Wildlife, Montrose, 

Colorado. 

Bureau of Reclamation (BOR). 1994. Animas-La Plata Project. Bald Eagle Population 

Distribution and Habitat Survey, December 1993- April1994. August, 1994. 

Reclamation Technical Center, Denver, Colorado. 

1989. Endangered species biological assessment for the Paradox Valley Unit, 

Point Source Division, Colorado River Basin Salinity Control Project, March 1989. BOR, 

Salt Lake City, Utah 

1986a. Paradox Valley Unit Colorado, Colorado River Basin Salinity Control 

Program, Deep well Injection Testing Program, Final Environmental Assessment, July 

1986. RO No. UC-EA-86-03. Upper Colorado Region, Durango Projects Office, 

Durango, Colorado. 

1986b. Finding of No Significant Impact for Deep well Injection Testing 

Program, Paradox Valley Unit, Colorado River Water Quality Improvement, July 7, 1986. 

RO No. UC-FONSI-86-03. BOR, Upper Colorado Region, Salt Lake City, Utah. 

1979. Colorado River Basin Salinity Control Project, Paradox Valley Unit, Final 

Environmental Statement. March 20, 1979. Upper Colorado Regional Office, Salt Lake 

City, Utah. 

1978a. Colorado River Basin Salinity Control Project, Paradox Valley Unit, 

Definitive Plan Report, September 1978. 

1978b. Colorado River Basin Salinity Control Project, Paradox Valley Unit, 

Draft Environmental Statement, May 11, 1978. INT DES 78-19. Upper Colorado 

Regional Office, Salt Lake City, Utah. 

n.d. Biological Assessment. Modify Operation of McPhee Reservoir and 

Acquire Additional Water for Fish and Wildlife Purposes. Durango, Colorado. 

34 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Clark, T.W. 1989. Conservation Biology of the Black-footed Ferret, Mustela nigripes, Spec. 

Sci. Rpt. No. 3. Wildlife preservation Trust. Philadelphia, PA. 

Federal Register. 1996. Endangered and Threatened Wildlife and Plants and animal taxa that 

are candidates for Listing or Endangered or Threatened Species. February 28, 1996. 

Vol. 61, No. 38, p 75-96. 

1995. Proposed Establishment of a Nonessential Experimental Population of 

Black-Footed Ferrets in Aubreg Valley, Arizona. Vol. 60, No. 220. November 15, 

1995. p. 57387. 

1995a. Final rule determining endangered status for the southwestern willow 

flycatcher. February 27, 1995. Vol. 60 (38), p. 10694. 

1995b. Final Rule to Reclassify the Bald Eagle From Endangered to 

Threatened in all Lower48 States. July 12, 1995. Vol. 60 No. 133, p. 36000. 

1994a. Proposed determination of critical habitat for the Mexican spotted owl. 

December 7, 1994. Vol. 59 (234), p. 63162. 

1994b. Animal candidate review for listing as endangered or threatened 

species, notice of review. November 15, 1994. Vol. 59 (219), p. 58982). 

1994c. Determination of critical habitat for four Colorado River endangered 

fishes, Final Rule. March 21, 1994. Vol. 59 (54), p. 13374. 

1993a. Proposed rule to list the southwestern willow flycatcher as endangered 

with critical habitat. July 23, 1993. Vol. 58 (140), p. 39495. 

1993b. Final rule to list the Mexican spotted owl as a threatened species. 

March 16, 1993. Vol. 58 (49), p. 14248. 

1991. Proposed rule to list the Mexican spotted owl as threatened. 

November 4, 1991. Vol. 56 (213), p. 5344. 

1974. LISTING OF COLORADO SQUAWFISH. January 4, 1974. Vol39 

(3), p. 1175. 

Evans, D. L. 1982. Status Report on Twelve Raptors. Wildlife No. 238. U.S. Department of 

the Interior, Fish and Wildlife Service, Washington, DC. 

35 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Ferguson, J. R. 1995. Correspondence received February 6, 1995. Biologist, Bureau of Land 

Management, Montrose, Colorado. 

Grunau, L. 1996. Correspondence received March 22, 1996. Environmental Review 

Coordinator, Colorado Natural Heritage Program, Fort Collins, Colorado. 

Hillman, C.N., R.L. Linder, and R.B. Dalhgren. 1979. Prairie Dog Distributions in areas 

inhabited by Black-Footed Ferrets. Am. Midi. Nat. 102:185-187. 

Holden P.B. and C. B. Stalnaker. 1975. Distribution of Fishes in the Dolores and Yampa River 

Systems of the Upper Colorado Basin. The Southwest Naturalist 19(4):403-412. 

Maddux H.R., L.A. Fitzpatrick, and W.R. Noonan. 1993. Colorado River endangered fishes 

critical habitat, draft biological support document. September 3, 1993. USFWS, Salt 

Lake City, Utah. 

McAda, C.W. and L.R. Kaeding. 1991. Movements of Colorado Squawfish During the 

Spawning Season in the Upper Colorado River. 1991. Trans. of the Amer. Fisheries 

Society 120:339-345. 

Ohmart, R. D., and R. J. Sell. 1980. The Bald Eagle of the Southwest with Special Emphasis 

on the Breeding Population of Arizona. Contract No. BR-14-06-300-267 4. U.S. 

Department of the Interior, Water and Power Resources Service. 

Olterman, J. 1995. Personal communication. March, 1995. Terrestrial Biologist, Colorado 

Division of Wildlife, Montrose, Colorado. 

Potter, M. 1996. Personal communication. March, 1996. Wildlife Officer, Colorado Division 

of Wildlife, Montrose, Colorado. 

Rocky Mountain/Southwestern Peregrine Falcon Recovery Team. 1977. American Peregrine 

Falcon, Rocky Mountain and Southwestern Population Recovery Plan. August 3, 1977. 

Denver, Colorado. 

Ryden, D. 1995. Personal communication, March 1995. U.S. Department of the Interior, Fish 

and Wildlife Service, Grand Junction, Colorado. 

Sedgwick, J.A. 1994. Memorandum: report on southwestern willow flycatcher surveys along 

the Animas, La Plata, and Mancos Rivers. National Biological Survey, Fort Collins, 

Colorado. 

Seethaler, K.H. 1978. Life history and ecology of Colorado squawfish (Ptychocheilus lucius) in 

the upper Colorado River Basin. M.S. Thesis. Utah State University, Logan, Utah. 

36 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

Snow, C. 1972. Technical Note, Habitat Management Series for Endangered Species, Report 

No. 1. U.S. Department of the Interior, Bureau of Land Management, Denver, Colorado. 

Spencer, D. A. 1976. Wintering of the Migrant Bald Eagles in the lower 48 States. National 

Agricultural Chemicals Association, Washington, DC. 

Steenhof, K. 1978. Management of Wintering Bald Eagles. FWS/OBS-78/79. Contract 

No.14-16-0006-77-030. U.S. Department of the Interior, Fish and Wildlife Service, 

Washington, DC. 

Tyus, H.M. 1991. Movement and Habitat Use of Young Colorado Squawfish in the Green 

River, Utah. Journal of Freshwater Ecology. 6:43-51. 

Tibbits, T.J., M.K. Sogge, and S.J. Sferra. 1994. A survey protocol for the southwestern willow 

flycatcher (Empidonax traillii extimus). April, 1994. Tech. Rpt. NPS/NAUCPRS/NRTR94-04. USFWS, NBS, and AGFD, Phoenix Arizona. 

U.S. Forest Service. nd. Mexican Spotted Owl Training Manual For Inventories and 

Monitoring, Pike and San Isabel National Forests, Comanche and Cimarron National 

Grasslands. USDA Forest Service, Pueblo, Colorado. 

_____ 1989. Endangered Species Technical Bulletin. Vol. XIV, No. 8, USDI, FWS, 

Washington, D.C. 

USFWS (U.S. Fish and Wildlife Service). 1994. Section 7 consultation, sufficient progress, and 

historic projects agreement and recovery action plan (RIPRAP}, Recovery 

implementation program for endangered fish species in the upper Colorado River Basin. 

September 8, 1994 (Revised). USFWS, Denver, Colorado. 

n.d. (estimated 1993). Colorado squawfish (Ptychoche/eilus lucius) facts. 

USFWS, Public Affairs, Denver, Colorado. 

1989. Endangered Species List, Paradox Valley Unit, Colorado River Water 

Quality Improvement Program. Memorandum to Bureau of Reclamation dated March 

20, 1989. USFWS, Colorado Field Office, Golden, Colorado. 

1988. Planning Aid Memorandum for the Paradox Valley Unit, Montrose 

County, Colorado. Memorandum to Bureau of Reclamation dated May 4, 1988. 

USFWS, Colorado State Office, Grand Junction, Colorado. 

1987. Final recovery implementation program for endangered fish species in 

the upper Colorado River Basin. September 29, 1987. USFWS, Denver, Colorado. 

37 
Paradox Valley Unit 

Supplemental Definite Plan Report/Environmental Assessment 

and Bureau of Reclamation. 1982. Part 2, Colorado River Fishery Project, 

Final Report Field Investigations. Salt Lake City, Utah, April, 1982. 

1977a. Endangered Species consultation-- Paradox Valley Unit. 

Memorandum dated October 18, 1977, to Bureau of Reclamation. USFWS, Denver, 

Colorado. 

1977b. Compliance with Section 7 of the Endangered Species Act of 1973. 

Memorandum dated February 15, 1977, to Bureau of Reclamation. USFWS, Salt Lake 

City, Utah. 

Valdez, R.A., W.J. Masslich, and A. Wasowicz. 1992. Dolores River native fish habitat 

suitability study (UDWR Contract No. 90-2559}, Report No. TR-272-02. April10, 1992. 

BIOJWEST Inc., Logan, Utah. 

Valdez, R.A., P. Mangan, M. Mcinerny, R.P. Smith. 1982. Tributary report: fishery 

investigations of the Gunnison and Dolores Rivers J..o.:. Part 2 Colorado River Fishery 

Project, Final Report, Field Investigations. April, 1982. FWS & BOR, Salt Lake City, 

Utah. 

Verner, J.E. 1995. Personal Communication. March, 1995. Wildlife Biologist, USFS, Pike/San 

Isabel National Forests, Pueblo, Colorado. 

Woodling, J. 1985. Colorado's little fish, a guide to the minnows and other lesser known fishes 

in the state of Colorado. Colorado Division of Wildlife, Denver, Colorado. 

38 
PARADOX VALLEY UNIT 

BIOLOGICAL OPINION 

Appendix C 

I 

United States Department of the Interihr 

FISH AL'fD WILDLIFE SERVICE 

\1ouncam-Prairie Region 

IN REPLY REFER TO. 

'>fAILING ADDRESS: 

ES I GJ-6-CO- 9 7- F- 0 lla.t Office Box 25486 

CO/KS /NE/UT Denver Federal Center 

Denver. Colorado 80225-0486 

Memorandum 

STREET LOCATIO": 

134 Union Blvd. 

Lakewood. Colorado 80228-l 

REC'D BOA WCAO-SD 

OFFICIAL PILE COPY 

JAN21 '97 

To: Southern Division Manager, Bureau of Reclamationf='Wl!'stern -...__ 

Colorado Area Office, Southern Division, Durango, Colorado 

From:: Regional Jirector, Region 6 

Fish and Wildlife Service 

Denver, :olorado 

Subject: Final Biological Opinion for Paradox Valley Unit Salinity 

Control Projec1: 

In accordance wit~ section 7 of the Endangered Species Act of 1973, as 

amended (16 U.S.C. 1531 et seq.), and the Interagency Cooperation 

Regulations (50 C?R 402), this transmits the Fish and Wildlife Service's 

final biological cpinion for impacts to federally listed endangered 

species for 1:he Paradox Valley Unit Salinity Control Project. 

Reference is made 1:0 your December 17, 1996, correspondence requesting 

initiation of formal consultation for the subject project. The Service 

concurs that the annual depletion of wa1:er from the Colorado River Basin 

"may affect" the endangered Colorado squawfish (Ptychocheilus lucjus), 

humpback chub (Gi1a cypha), bonytail (~ eleqans), and razorback 

sucker (Xyraucher.. -:.exanus) and "may affect" their c~itical habitat. 

BIOLOGICAL OPINIC:i 

Based '.lpon the best scientific and commercial information that is 

curren~:ly available, it is the Service's biological opinion that the 

proposed projec1:, as described below, is likely to jeopardize the 

continued existence of the Colorado squawfish, humpback chub, bony~:ail, 

and razorback sucker and result in the destruc1:ion or adverse 

modif~caticn of their critical habitat. The Service has developed 

reasonable and prudent alternatives to avoid the likelihood of jeopardy 

to the endangered fishes and to avoid destruction or adverse 

modification of their critical habitat. 

CONSULTATIC~ HISTJRY 

The Bureau of Reclamal:ion has intermittently consl:ructed and tested a 

orine removal fac~li ty in the Paradox •:alleoy since 197 9. The Service 

informally consulted on the project in 1977 with the knowledge that 

testing of the facility was necessary. The Service then formally 

consulted en the project ~n 1989 IES/GJ-6-C0-89-F-09) due 1:0 impacts to 

::he Colorado squa·•fish, bonytail, and humpback chub from a proposed 
1294- 406- 232 

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AUGUST 1995 

Figure [- l