An Evaluation and Review of Water-Use Estimates and 

Flow Data for the Lower Klamath and Tule Lake National 

Wildlife Refuges, Oregon and California

Prepared in cooperation with the Bureau of Reclamation

Scientific Investigations Report 2006–5036

U.S. Department of the Interior

U.S. Geological Survey
Cover: View north across the Lower Klamath Refuge looking towards the Klamath Hills and Swan Lake Point. 

(Photograph taken by Patrick C. Palmer, U.S. Geological Survey, 2001)
An Evaluation and Review of Water-Use 

Estimates and Flow Data for the Lower 

Klamath and Tule Lake National Wildlife 

Refuges, Oregon and California

By John C. Risley and Marshall W. Gannett

Prepared in cooperation with the 

Bureau of Reclamation

Scientific Investigations Report 2006–5036

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

P. Lynn Scarlett, Acting Secretary

U.S. Geological Survey

P. Patrick Leahy, Acting Director

U.S. Geological Survey, Reston, Virginia: 2006

For sale by U.S. Geological Survey, Information Services

Box 25286, Denver Federal Center

Denver, CO 80225

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endorsement by the U.S. Government.

Although this report is in the public domain, permission must be secured from the individual copyright owners to 

reproduce any copyrighted materials contained within this report.

Suggested citation:

Risley, J.C., and Gannett, M.W., 2006, An evaluation and review of water-use estimates and flow data for the 

Lower Klamath and Tule Lake National Wildlife Refuges, Oregon and California: U.S. Geological Survey Scientific 

Investigations Report 2006–5036, 18 p. 
iii

Contents

Abstract ................................................................................................... 1

Introduction................................................................................................ 1

Purpose and Scope ................................................................................. 3

Study Area .......................................................................................... 3

Refuge Water Management ........................................................................... 3

Water-Use Estimates Based on Open-Water Evaporation and Evapotranspiration Losses ... 5

Land-Use Categories .............................................................................. 5

Grain .......................................................................................... 6

Seasonal Wetland ........................................................................... 6

Wetlands with Emergent Vegetation ...................................................... 6

Open Water .................................................................................... 6

Salinity Flushing .................................................................................... 7

Lower Klamath Refuge ........................................................................... 7

Tule Lake Refuge .................................................................................... 8

Uncertainty in Open-Water Evaporation and Evapotranspiration Estimates ............... 10

Water-Use Estimates Based on Inflows and Outflows ............................................. 10

Lower Klamath Refuge ........................................................................... 10

Tule Lake Refuge .................................................................................... 11

Refuge Water Budgets ................................................................................. 14

Flow Data Quality.......................................................................................... 15

Accuracy of the Records........................................................................... 15

Ady Canal at State Line Road ..................................................................... 15

Klamath Straits Drain at State Line Road......................................................... 16

D Pumping Plant .................................................................................... 16

Suggested Improvements to the Flow-Data-Collection Network ........................... 16

Coordination ................................................................................. 16

Documentation .............................................................................. 16

Equipment Modernization .................................................................. 17

Check Measurements ........................................................................ 17

Additional Flow Sites ........................................................................ 17

Summary and Conclusions .............................................................................. 17

Acknowledgments ....................................................................................... 18

References Cited.......................................................................................... 18\
iv

Figures

Figure 1. Map showing Lower Klamath and Tule Lake National Wildlife Refuges,

Oregon and California ..................................................................... 2

Figure 2. Diagram showing major flow paths entering and exiting the Lower Klamath

and Tule Lake National Wildlife Refuges, Oregon and California ..................... 4

Figure 3. Graph showing Lower Klamath National Wildlife Refuge net inflow, Oregon

and California, 1962–2005 .................................................................. 12

Figure 4. Graphs showing monthly flows for Ady Canal, Klamath Straits Drain, and D

Pumping Plant, Lower Klamath and Tule Lake National Wildlife Refuges,

Oregon and California, 1961 through 2005 ................................................ 13

Figure 5. Diagram showing water budget, derived from an approximation of

2003–2005 conditions, for Lower Klamath and Tule Lake National Wildlife

Refuges, Oregon and California............................................................ 14

Tables

Table 1. Approximate water use by land-use category in the Lower Klamath and

Tule Lake National Wildlife Refuges, Oregon and California ........................... 5

Table 2. Area of land in different land-use categories in the Lower Klamath

National Wildlife Refuge, Oregon and California, 2003-2005 ........................... 7

Table 3. Estimated water use in the Lower Klamath National Wildlife Refuge,

Oregon and California, 2003-2005 ......................................................... 8

Table 4. Area of land in different land-use categories in the Tule Lake National

Wildlife Refuge, Oregon and California, 2003–2005 .................................... 9

Table 5. Estimated water use in the Tule Lake National Wildlife Refuge, Oregon and

California, 2003-2005 ........................................................................ 9

Table 6. Estimated 2003-2005 mean annual inflows to and outflows from the Lower

Klamath and Tule Lake National Wildlife Refuges, Oregon and California ......... 11

Table 7. Mean net inflows to the Lower Klamath National Wildlife Refuge, Oregon

and California, 1962-2005 and 2003-2005 ................................................ 11

Table 8. Accuracy ratings for Ady Canal, Klamath Straits Drain, and D Pumping

Plant flow records, Oregon and California................................................ 15
Conversion Factors and Datums

Inch/Pound to SI

Multiply By To obtain

acre 0.4047 hectare

acre 0.004047 square kilometer

acre-foot per day (acre-ft/d) 1,233 cubic meter per day

acre-foot per year (acre-ft/yr) 1,233 cubic meter per year

acre-foot per year (acre-ft/yr) 0.001233 cubic hectometer per year

cubic foot per second (ft3/s) 0.02832 cubic meter per second

gallon per minute (gal/min) 0.06309 liter per second

foot (ft) 0.3048 meter

inch (in.) 2.54 centimeter

inch (in.) 25.4 millimeter

mile (mi) 1.609 kilometer

million gallons per day (Mgal/d) 0.04381 cubic meter per second

square mile (mi2) 2.590 square kilometer 

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows:

 °F=(1.8 × °C)+32.

Datums

Vertical coordinate information is referenced to the National Geodetic Vertical Datum of 1929 

(NGVD29).

Horizontal coordinate information is referenced to the North American Datum of 1927. 

Elevation, as used in this report, refers to distance above the vertical datum.
vi

This page is intentionally left blank.
Abstract

The Lower Klamath and Tule Lake National Wildlife 

Refuges, located in the upper Klamath Basin of Oregon and 

California, encompass approximately 46,700 and 39,100 acres, 

respectively. Demand for water in the semiarid upper Klamath 

Basin has increased in recent years, resulting in the need to 

better quantify water availability and use in the refuges. This 

report presents an evaluation of water-use estimates for both 

refuges derived on the basis of two approaches. One approach 

used evaporation and evapotranspiration estimates and the 

other used measured inflow and outflow data. The quality of 

the inflow and outflow data also was assessed.

Annual water use in the refuges, using evapotranspiration 

estimates, was computed with the use of different rates for 

each of four land-use categories. Annual water-use rates for 

grain fields, seasonal wetlands, permanently flooded wetlands 

with emergent vegetation, and open-water bodies were 2.5, 

2.9, 2.63, and 4.07 feet per year, respectively. Total water use 

was estimated as the sum of the products of each rate and the 

number of acres in its associated land-use category. Mean 

annual (2003–2005) water use for the Lower Klamath and 

Tule Lake refuges was approximately 124,000 and 95,900 

acre-feet, respectively. To estimate water deliveries needed 

for each refuge, first, annual precipitation for 2003–2005 was 

subtracted from the annual water use for those years. Then, 

an adjusted total was obtained by adding 20 percent to the 

difference to account for salinity flushing. Resulting estimated 

mean annual adjusted needed water deliveries in 2003–2005 

for the Lower Klamath and Tule Lake refuges were 107,000 

and 82,800 acre-feet, respectively.

Mean annual net inflow to the refuges for 2003–2005 

was computed by subtracting estimated and measured surfacewater outflows from inflows. Mean annual net inflow during 

the 3-year period for the Lower Klamath refuge, calculated 

for a subsection of the refuge, was approximately 73,700 

acre-feet. The adjusted needed water delivery for this section 

of the refuge, calculated from evapotranspiration estimates, 

was approximately 77,600 acre-feet. For the Tule Lake 

refuge, mean annual net inflow during the 3-year period was 

approximately 76,100 acre-feet, which is comparable to the 

estimated annual needed water delivery for the refuge of 

82,800 acre-feet. 

For 1962–2005, mean annual net inflow to the Lower 

Klamath refuge was approximately 49,800 acre-feet, about 

23,900 acre-feet less than for 2003–2005. Although mean 

April–September net inflows for 1962–2005 and 2003–2005 

have remained fairly constant, annual net inflow has increased 

for October–March, which accounts for the difference. 

Consistently higher autumn and winter flow deliveries 

since the mid-1980s reflect a significant change in refuge 

management. More sections of the refuge are currently 

managed as seasonal wetlands than were in the 1960s and 

1970s.

Flow records for the Ady Canal at State Line Road, 

Klamath Straits Drain at State Line Road, and D Pumping 

Plant were evaluated for their data quality. On the basis of 

USGS flow-record criteria, all three flow records were rated as 

“poor.” By definition, 95 percent of the daily flows in a record 

having this rating could be in error by more than 15 percent. 

Introduction

Increased pressure on water resources in the upper 

Klamath Basin of California and Oregon for wildlife, 

irrigation, and power generation has created a need to 

quantify water availability and use. Water supplied for habitat 

in wildlife refuges managed by the U.S. Fish and Wildlife 

Service (USFWS) constitutes a significant water use in the 

basin. The Bureau of Reclamation’s (BOR) Klamath Project 

(Project) provides water to both the Lower Klamath and Tule 

Lake National Wildlife Refuges and also, at times, stores 

surplus water in the wildlife refuges to augment flow for 

habitat enhancement in the Klamath River. These refuges 

use water that is largely irrigation-return flow or runoff from 

springs and are at the lower, downgradient end of the Project, 

where excess water is ultimately pumped back into the 

Klamath River (fig. 1). 

An Evaluation and Review of Water-Use Estimates and 

Flow Data for the Lower Klamath and Tule Lake National 

Wildlife Refuges, Oregon and California

By John C. Risley and Marshall W. Gannett
Figure 1. Lower Klamath and Tule Lake National Wildlife Refuges, Oregon and California.

or888_fig01

41°50'

42°00'

121°50' 121°40' 121°30'

Sheepy

Creek

Cottonwood Creek Willow Creek

River

Lost

J Canal

D Canal

J Canal

Ady Canal

N Canal

Q Canal

R Canal

P Canal

Klamath Straits

Drain

North Canal

LOWER KLAMATH

NATIONAL WILDLIFE REFUGE

TULE LAKE

NATIONAL

WILDLIFE REFUGE

39

139

139

97

State Line Road

Area K

Leaselands

"D" Pumping

Plant

"E-EE" Pumping

Plant

"F-FF" Pumping

Plant

AREA J

Sump 3

Leaselands

Sump 1B

Sump1A

Sump 2

Leaselands

Base from U.S. Geological Survey digital data, 1:24,000 and 1:100,000

Universal Transverse Mercator projection, Zone 13.

Datum is North American Datum of 1927

Wildlife Refuge areas from U.S. Fish and Wildlife Service, 2001, 1:24,000 

Irrigation boundaries from U.S. Bureau of Reclamation, 2004, 1:100,000

OREGON

CALIFORNIA

Sheepy Ridge

Anderson-Rose

Diversion Dam +

+

Worden

Tulelake

+

Klamath

Falls Area shown

on this map

Upper

Klamath

Basin CASCADE RANGE

Medicine

Lake Volcano

OREGON

CALIFORNIA

Upper

Klamath

Basin

Leaselands

Wildlife Refuge

EXPLANATION

0 5 MILES

0 5 KILOMETERS

As a result of the BOR’s need to carefully manage water 

provided by the Project to all users, it is important to be 

able to assess its ability to estimate water use by the refuges 

with currently available information. In addition, the BOR 

also is interested in potential ways to improve measurement 

accuracy of the water delivered to and removed from the 

Lower Klamath and Tule Lake National Wildlife Refuges to 

better quantify the overall Project agricultural and refuge water 

use. To this end, in 2005, the BOR asked the U.S. Geological 

Survey Oregon Water Science Center to evaluate water use 

and diversion and return-flow data in the Lower Klamath and 

Tule Lake National Wildlife Refuges. 

 Water-Use Estimates and Flow Data for the Lower Klamath and Tule Lake National Wildlife Refuges, OR and CA
Purpose and Scope

The purpose of this report is to present the results of an 

assessment of the availability of inflow, outflow, open-waterevaporation, and vegetative-evapotranspiration data to estimate 

water use for the refuges and to provide an approximation 

of the error associated with the estimates. In the process of 

estimating water use for the refuges, a description of water 

routing and management, and therefore the water budget, 

was formulated and is described herein. A secondary goal 

of this assessment was to provide suggestions for improved 

data-collection methods and identify data-collection sites that 

would help reduce error in refuge water-use estimates.

The scope of this assessment and review was limited to 

the Lower Klamath and Tule Lake National Wildlife Refuges 

(fig. 1). The assessment included an analysis of:

• Evapotranspiration loss estimates,

• Inflows and outflows to and from the refuges (water 

budgets), and

• Data quality and general water-use estimation error.

Of specific interest was the comparison of measured and 

estimated water flows to and from the refuges and estimates 

of open-water-evaporation and evapotranspiration losses 

from areas of terrestrial and aquatic vegetation. Collection 

of additional data in the field was limited to a few check 

measurements of flow; significant data collection was outside 

the scope of this review. Much of the information evaluated in 

this review was obtained from the BOR’s Klamath Basin Area 

Office and the USFWS.

Study Area

The study area is located near Klamath Falls in 

southern Oregon and northern California (fig. 1). The 

Lower Klamath and Tule Lake National Wildlife Refuges 

are two of six National Wildlife Refuges, managed by 

the USFWS in the upper Klamath Basin. Established by 

President Theodore Roosevelt in 1908, the Lower Klamath 

refuge is the oldest waterfowl refuge in the Nation. 

Composed of a mix of permanent and seasonal freshwater 

marshes, open water, grassy uplands, and croplands, it has 

a total area of approximately 46,700 acres. The refuge is 

intensively managed to provide feeding, resting, nesting, 

and brood-rearing habitat for waterfowl and other water 

birds. Approximately 10,000–12,000 acres of the refuge are 

leased or farmed cooperatively for cereal grain and alfalfa 

production. Waste grain, sometimes a set percentage of the 

harvest, is left on the fields each autumn, and becomes a major 

source of food for migrating and wintering waterfowl. The 

Tule Lake refuge was established in 1928 and encompasses 

approximately 39,100 acres of mostly open water and 

croplands. Approximately 17,000 acres of these lands are 

leased to farmers. The two refuges are adjacent to the southern 

edge of the Project. In total, the two refuges and the Project 

encompass approximately 240,000 acres. 

Prior to agricultural development, the Klamath Basin 

had approximately 185,000 acres of shallow lakes and 

freshwater marshes (U.S. Fish and Wildlife Service, 2005). A 

large wetland marsh and lake covered the region between the 

Klamath River and the present day Lower Klamath National 

Wildlife Refuge. Tule Lake was the terminus of the closed 

Lost River Basin. Unlike other closed basin lakes, Tule Lake 

was not saline probably because of lake discharge to the 

ground-water system to the south, allowing circulation through 

the lake and thus preventing the accumulation of salts and 

deposition of evaporites.

Beginning in 1905 and continuing through the 1950s, 

much of the Lower Klamath and Tule Lake wetlands were 

drained for agricultural development. Today, less than 25 

percent of the original wetlands remain (U.S. Fish and 

Wildlife Service, 2005). 

The Tule Lake and Lower Klamath Lake refuges occupy 

sediment-filled structural basins east of the Cascade Range 

and north of Medicine Lake Volcano. The downfaulted basins 

are surrounded by faulted Tertiary and Quaternary volcanic 

rocks and Tertiary lacustrine deposits (Gay and Aune, 

1958). The two refuges are separated by a linear, north-south 

trending upland with prominent fault escarpments known as 

Sheepy Ridge, which is composed of Tertiary volcanic and 

sedimentary deposits. The basin-filling sediment consists 

of fine-grained lacustrine deposits ranging in age from late 

Tertiary to Quaternary (Rieck and others, 1992).

Refuge Water Management

With the development of the Project in the early 1900s, 

the Lower Klamath and Tule Lake National Wildlife Refuges 

have become highly regulated systems. Water enters the two 

refuges by a variety of pathways, which include precipitation, 

natural runoff, ground-water seepage, pipes, and irrigation 

canals. Water leaves the refuges through open-water 

evaporation, evapotranspiration, drainage canals, and groundwater seepage (fig. 2).

Refuge Water Management 
Project water enters the Lower Klamath refuge 

through the Ady Canal and through the D Pumping Plant. 

Natural surface-water flow enters the refuge from Sheepy, 

Cottonwood, and Willow Creeks. Combined mean annual flow 

from these three creeks is approximately 30 ft3/s on the basis 

of miscellaneous flow measurements made throughout water 

year 1955 (Wood, 1960). However, these flows have decreased 

because of ground-water pumping on private lands outside of 

the refuge within the last 50 years. Flow from the D Pumping 

Plant enters the Lower Klamath refuge via the P Canal, 

located on the eastern boundary of the refuge. P Canal flows, 

along with flows from the Ady Canal, are used to flood 40–50 

refuge units. Units are defined land areas within the refuges 

that are managed for a specific purpose and in a specific way. 

For example, some units are permanently flooded wetlands, 

whereas other units are flooded seasonally. Seasonally flooded 

units typically are filled in the autumn and drained during the 

following spring or summer. Other units are leased to private 

farmers and used for grain or hay production. Although most 

of the Lower Klamath refuge is located south of State Line 

Road (California Hwy 161) in California, a portion of the 

refuge, known as the Area K Lease Lands, is located on the 

northern side of the State Line Road. Those units are leased 

to private farmers for grain production. In addition to openwater evaporation, evapotranspiration from areas of terrestrial 

or aquatic vegetation, and ground-water seepage, water also 

leaves the refuge northward through the Klamath Straits Drain. 

From the refuge, flow in the drain is pumped through the E-EE 

and F-FF Pumping Plants to the Klamath River. 

The Tule Lake refuge comprises four major sumps: Sump 

1A, Sump 1B, Sump 2, and Sump 3 (fig. 1). Sump 1A is a 

permanent open-water body with a minimum and maximum 

water elevation of 4,034 and 4,035.5 ft above NGVD29, 

respectively. The minimum elevation is maintained under 

Endangered Species Act (ESA) guidelines for Lost River 

and shortnose sucker habitat protection. One source of water 

entering Sump 1A is the Lost River, which is regulated by 

the Anderson-Rose Diversion Dam. Flow also is pumped 

into Sump 1A from drainage canals in the Tulelake Irrigation 

District (TID) close to the refuge boundary of the sump. TID 

return flows also enter the sump through shallow groundwater seepage in this same area. Additional surface-water flow 

enters Sump 1A via the N Canal, which is located along the 

eastern and northeastern boundary of the refuge. When water 

in Sump 1A rises above the maximum elevation, it is pumped 

to the Lower Klamath refuge via the D Pumping Plant and 

through a tunnel under Sheepy Ridge. Water also is sent to 

the Lower Klamath refuge at other times when deliveries are 

requested by refuge managers. Smaller water volumes from 

Sump 1A also are used as water supply for agriculture and 

wildlife habitat needs in the adjoining Sumps 2 and 3. Sump 

1B is hydrologically connected to Sump 1A through a narrow, 

gated canal. For many years, Sump 1B was managed as a 

permanent open-water body. However, in recent years Sump 

1B has been managed as either a year-round water body or 

sometimes a seasonal wetland through regulation of the flow 

in the canal separating the two sumps. 

Figure 2. Major flow paths entering and exiting the Lower Klamath and Tule Lake National Wildlife Refuges, Oregon and California.

ET

ET

Precipitation

Ady Canal

Straits Drain

N canal

Lost River

Pumped

inflows

N canal

D Pump

Lower Klamath

National Wildlife

Refuge

Tule Lake National

Wildlife Refuge

Precipitation

Sheepy

Creek

Willow

Creek

Cottonwood

Creek

GW flow

GW flow

GW flow

 Water-Use Estimates and Flow Data for the Lower Klamath and Tule Lake National Wildlife Refuges, OR and CA
Almost all of the Sump 2 and 3 lands are leased to private 

farmers for grain production. However, approximately 5–10 

percent of the units in these two sumps are rotated every year 

between grain production, permanent flooding (an entire year), 

and seasonal flooding. Sump 2 receives water from Sumps 1A 

and 1B through the Q and R Canals. Drainage water from 

Sump 2 is pumped back into Sump 1A. Most water for Sump 

3 is delivered through the N Canal. A smaller volume of water 

for Sump 3 comes from Sump 1A. Drainage water is pumped 

out of Sump 3 back into the N Canal and Sumps 1A and 1B. 

To improve their understanding of water management 

for the Tule Lake refuge, the USFWS developed a surfacewater budget for the refuge (Tim Mayer, U.S. Fish and 

Wildlife Service, Portland, Oregon, written commun., 2005). 

Data used in the budget analysis were based on pump flow 

records and miscellaneous surface-water stream and canal 

flow measurements made by the BOR, USFWS, and Tulelake 

Irrigation District from 1988 to 1998. Because of limited 

available documentation regarding data from these agencies, 

it is acknowledged that potential error could be significant. By 

USGS surface-water flow measurement standards, these data 

would be rated as “poor,” with errors greater than 15 percent.

The USFWS surface water-budget analysis for Sumps 

1A and 1B had a residual of approximately –30,300 acre-ft/yr 

(–41.8 ft3/s), Sump 2 had a residual close to zero, and Sump 

3 had a residual of approximately 11,300 acre-ft/yr (15.6 

ft3/s). For the entire Tule Lake refuge, there was a net surfacewater flow residual of –19,000 acre-ft/yr (26.2 ft3/s). These 

residuals, or differences between surface-water inflow and 

outflow, are the result of both surface-water flow measurement 

error and probable unmeasured ground-water inflow and 

outflow. For each residual, the proportion attributed to surfacewater measurement error versus the proportion attributed 

to ground-water flow is unknown. Possible ground-water 

inflow and outflow suggested by the residuals in the USFWS 

surface-water budget analysis is consistent with the general 

northwestern to southeastern ground-water flow direction for 

the region surrounding the refuge. On average, the groundwater table of the Lower Klamath refuge is approximately 

50–60 ft higher than the Tule Lake refuge. As a result, there is 

a significant ground-water gradient underneath Sheepy Ridge, 

which indicates potential ground-water flow from Lower 

Klamath refuge into Sump 1A. Although not confirmed, it is 

possible that there is ground-water discharge through diffuse 

seepage or submerged springs into Sump 1A near the base 

of Sheepy Ridge. For Sump 3, it is possible that the surplus 

water leaves the sump through seepage into the ground-water 

system. Because the entire Tule Lake refuge was once a 

natural lake, the construction of deep drainage canals in Sump 

3 may have increased seepage rates by penetrating through the 

less permeable sedimentary soil layers near the surface.

Water-Use Estimates Based on 

Open-Water Evaporation and 

Evapotranspiration Losses

As part of this assessment, open-water evaporation 

and evapotranspiration losses from areas of emergent and 

terrestrial vegetation in the refuges were quantified for the 

purpose of comparison with measured inflows and outflows to 

and from the refuges. This comparison allowed the estimation 

of water use in the refuges by two different methods. 

Although more than 90 percent of the land area of the 

two refuges is supplied in some way by Project water, a few 

upland units and some small land parcels, which are separate 

from the main bodies of the refuges, were not included in this 

assessment because they do not receive Project water. 

Land-Use Categories

An estimation of total water use in the refuges was made 

by summing water use from four land-use categories: grain, 

seasonal wetland, permanently flooded wetland with emergent 

vegetation, and open water. Approximate monthly and annual 

water-use rates for the land-use categories, derived from recent 

studies by the USFWS and Burt and Freeman (2003), are 

shown in table 1. These rates are multiplied by total acreage of 

the land-use categories to derive total water-use volumes.

Category Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. Apr.–Oct. Annual

Grain 0.034 0.066 0.138 0.201 0.323 0.417 0.448 0.370 0.262 0.154 0.056 0.032 2.18 2.50

Seasonal wetland – – – – – – – – .967 .967 .967 – – 2.90

Emergent vegetation .014 .040 .122 .188 .270 .394 .567 .485 .324 .179 .030 .014 2.41 2.63

Open water .060 .094 .201 .342 .566 .629 .714 .640 .510 .262 .000 .048 3.66 4.07

Table 1. Approximate water use by land-use category in the Lower Klamath and Tule Lake National Wildlife Refuges, Oregon and California.

[Values are in feet. Sources: Burt and Freeman, 2003; Tim Mayer, U.S. Fish and Wildlife Service, Portland, Oregon, written commun., 2005. –, no data]

Water-Use Estimates Based on Open-Water Evaporation and Evapotranspiration Losses 
Grain 

Approximately 55 percent of Tule Lake and 27 percent 

of Lower Klamath refuge land areas are dedicated to grain 

production. The USFWS estimated that 2.5 ft/yr was an 

approximate value of water use for grain production lands 

(Tim Mayer, U.S. Fish and Wildlife Service, Portland, Oregon, 

written commun., 2005). This estimate was based on data in 

the State of Oregon’s hydrology report for the Klamath Basin 

(Oregon Water Resources Department, 1971), local irrigation 

district delivery guidelines, and the USFWS assessment of 

water delivery needs for marsh vegetation. Burt and Freeman 

(2003) also made estimates of annual evapotranspiration for 

1999, 2000, and 2001 for barley, oats, and wheat that ranged 

from 2.22 to 2.64 ft for the Tule Lake and Lower Klamath 

refuge areas. On the basis of these studies, 2.5 ft/yr was 

selected as an appropriate annual water-use rate for grain 

production areas. Mean monthly reference evapotranspiration 

rates estimated for the Klamath Falls BOR AgriMet station 

(KFLO), located approximately 15–20 mi north of the refuges, 

were used to partition the annual grain water use into monthly 

rates, as shown in table 1 (Bureau of Reclamation, 2004). 

Seasonal Wetland

Roughly half of the Lower Klamath refuge and 5 percent 

of the Tule Lake refuge contain seasonal wetlands, which are 

flooded (sometimes referred to as “floodup”) generally during 

the autumn (September-November). They are dewatered in 

the late spring and early summer through a combination of 

drainage and evaporation. Each seasonal-wetland unit has 

a target water level associated with it. During the autumn 

floodup, when sufficient water deliveries are sent to the 

refuges, water levels are manipulated in each unit until the 

target level is reached (Tim Mayer, U.S. Fish and Wildlife 

Service, Portland, Oregon, written commun., 2005). Mayer 

and Thomasson (2004) measured the volume of water needed 

to fill three representative seasonal-wetland units in the Lower 

Klamath refuge. In their study, this volume of water was 

also partitioned into soil saturation requirements, surfacewater volume, and evapotranspiration losses. On average, the 

floodup volume for the units was 2.90 ft from SeptemberNovember (table 1). Of this amount, about one-half (1.5 ft) 

is used to saturate the soils, and roughly 0.5 ft is lost through 

evaporation and evapotranspiration during October–April. In 

late spring, the remaining 0.9 ft of delivered floodup water, 

plus approximately 0.9 ft of accumulated precipitation that 

falls between October and April, is drained from the seasonal 

units and leaves the refuges.

Wetlands with Emergent Vegetation

Permanent (year-round) wetland units encompass 

approximately 23 percent of the Lower Klamath refuge and 

40 percent of the Tule Lake refuge. Two rates were used to 

estimate water use in these units. The emergent-vegetation 

water-use rate was applied to the vegetation-dominated portion 

of each unit. The open-water evaporation rate (described 

below) was applied to the open-water portions.

The rate of water use by emergent vegetation was 

estimated using a USFWS model based on the PriestlyTaylor evapotranspiration equation, which uses minimum 

and maximum daily air temperatures as input (Ronald R. 

Thomasson, U.S. Fish and Wildlife Service, Portland, Oregon, 

written commun., 2005). The model was calibrated using 

measured field data from energy budget studies made at 

several locations in the Klamath National Wildlife Refuges 

(W.R. Bidlake and K. Payne, U.S. Geological Survey, 

written commun., 1998). Using a simulation period of 

1961–1990, the model predicted a median April–October total 

evapotranspiration loss of 2.41 ft. This value and monthly 

reference evapotranspiration rates estimated for the Klamath 

Falls BOR AgriMet station (KFLO) were used to estimate 

evapotranspiration losses for the months of November 

through March (Bureau of Reclamation, 2004). The annual 

evapotranspiration rate for the emergent vegetation category 

was then estimated to be 2.63 ft (table 1).

Open Water

Pan evaporation data from the Tule Lake Agricultural 

Station were used to estimate evaporation from open-water 

portions of the permanent wetlands. The data were from April 

through October 1956–1981. Average total April–October pan 

evaporation for the period of record was 4.08 ft. Because the 

open-water areas on the refuges are small and shallow, a pan 

evaporation coefficient of 0.9 was used (Dunne and Leopold, 

1978). This produced a mean April–October open-water 

evaporation rate of 3.66 ft, as shown in table 1. Year-round 

monthly pan evaporation data collected at the Klamath Falls 

Agricultural Station (located farther away from the refuges 

than the Tule Lake Agricultural Station) were used to estimate 

open-water evaporation for the months of November through 

March. On average, the Tule Lake pan evaporation rates are 

95 percent of the Klamath Falls pan evaporation rates due 

to climatic differences. Therefore, mean November–March 

Klamath Falls pan evaporation data were simply multiplied 

by 0.95 to estimate Tule Lake pan evaporation data for those 

months. Those estimates were then adjusted further by using 

a 0.9 pan evaporation coefficient to estimate open-water 

evaporation. The mean annual rate for open-water evaporation 

was estimated to be 4.07 ft (table 1). 

 Water-Use Estimates and Flow Data for the Lower Klamath and Tule Lake National Wildlife Refuges, OR and CA
Salinity Flushing

In addition to estimating evapotranspiration losses, 

it also is necessary to account for the additional water in 

the refuge units needed to prevent salinity accumulation 

over time. Specific conductance data collected at irregular 

intervals by both the BOR and USGS at various inflow and 

outflow locations near the refuges from the early 1990s 

to the present show that specific conductance levels have 

remained relatively constant over time (MacCoy, 1994; Cindy 

Williams, Bureau of Reclamation, written commun., 2005). 

The volume of additional water needed to avoid exceeding 

a maximum salinity level for flows leaving a water body 

can be estimated by multiplying the net evapotranspiration 

times a salinity factor. Net evapotranspiration is estimated as 

evapotranspiration minus precipitation. The salinity factor 

is estimated as the maximum outflow specific conductance 

level divided by the difference between outflow specific 

conductance and measured inflow specific conductance.

The Lost River is a major point of inflow for the Tule 

Lake refuge. Specific conductance data collected on the 

Lost River at State Line Road has a mean of approximately 

0.5 millisiemens per centimeter. To prevent outflow specific 

conductance from exceeding 3.0 millisiemens per centimeter, 

a salinity factor of 1.2 would be needed. For the Lower 

Klamath refuge, mean inflow specific conductance for the 

Ady Canal at State Line Road and Pumping Plant D is 0.14 

and 0.60 millisiemens per centimeter, respectively. Salinity 

factors based on these specific conductance levels were 

computed as 1.16 and 1.25, respectively. On the basis of these 

calculations, an overall salinity factor of 1.20 (20 percent of 

the net evapotranspiration) seemed reasonable to apply to both 

refuges. The U.S. Fish and Wildlife Service also estimated a 

salinity factor of 1.20 for both refuges in their analyses (Tim 

Mayer, U.S. Fish and Wildlife Service, Portland, Oregon, 

written commun., 2005).

Lower Klamath Refuge

The Lower Klamath refuge is divided into approximately 

50 land-use units. A breakdown of the cumulative acres by 

area and land-use category for 2003, 2004, and 2005 is shown 

in table 2. Acreage data for each land-use category are from 

the annual USFWS habitat plans for the refuge. However, the 

total number of acres shown in table 2 does not include all of 

the Lower Klamath refuge. Some small, noncontiguous units 

and nonirrigated upland areas are not included because precise 

data for both refuges was not easily obtainable. However, the 

table does show totals for essentially all units that typically are 

irrigated for a particular land use. Approximately 35,000 acres, 

most of the refuge, is located in California south of State Line 

Road. With the exception of approximately 5,000–7,000 acres, 

most of this area is irrigated by Project water. Some units that 

are not irrigated with Project water are irrigated with natural 

surface-water runoff from Sheepy, Cottonwood, and Willow 

Creeks and ground-water discharge. An additional 6,600 acres 

of the refuge are located north of State Line Road. Known as 

the Area K Lease Lands, these units are leased to farmers on 

an annual basis for grain production and are irrigated with 

Project water. The water for these units comes from the Ady 

Canal at various diversion points upstream of the Ady Canal 

flow gage on State Line Road.

Land-use category

Area (acres)

Project Area K Non-project Total

2003 Habitat Plan

Grain 3,611 6,391 0 10,002

Seasonal wetland 14,992 207 7,718 22,917

Emergent vegetation 5,399 0 0 5,399

Open water 4,492 0 0 4,492

 Total 28,494 6,598 7,718 42,810

2004 Habitat Plan

Grain 6,304 6,391 0 12,695

Seasonal wetland 15,851 207 5,671 21,729

Emergent vegetation 5,399 0 0 5,399

Open water 4,492 0 0 4,492

 Total 32,046 6,598 5,671 44,315

2005 Habitat Plan

Grain 5,135 6,352 0 11,488

Seasonal wetland 14,213 179 5,329 19,721

Emergent vegetation 5,899 0 0 5,899

Open water 4,480 0 0 4,480

 Total 29,727 6,532 5,329 41,588

Table 2. Area of land in different land-use categories in the Lower 

Klamath National Wildlife Refuge, Oregon and California, 2003-2005.

[Project, lands south of State Line Road irrigated by Bureau of Reclamation 

Project; Area K, Area K leased lands and all other units north of State Line 

Road; Non-Project, lands south of State Line Road not irrigated with Project 

water. Some small units of refuge property near the boundaries were not 

included. Source: Tim Mayer, U.S. Fish and Wildlife Service, Portland, 

Oregon, written commun., 2005]

Water-Use Estimates Based on Open-Water Evaporation and Evapotranspiration Losses 
annual evapotranspiration and evaporation rates for grain, 

seasonal wetland, emergent vegetation, and open water shown 

in table 1. For the largest open-water permanent wetland unit 

(Unit 2), the emergent vegetation evapotranspiration rate 

was applied to 83 percent of the area, and the open-water 

evaporation rate was applied to the remaining 17 percent. A 

mixture of other emergent vegetation and open-water ratios 

were applied to the other permanent wetland units (Tim 

Mayer, U.S. Fish and Wildlife Service, Portland, Oregon, 

written commun., 2005).

The mean annual water use for the entire Lower Klamath 

refuge for 2003–2005 (including seasonal-wetland water use) 

was approximately 124,000 acre-ft (table 3). This volume 

includes water use in all units served by Project water on both 

sides of State Line Road plus approximately 5,000–7,000 

acres of land not served by Project water. However, the 3-year 

mean annual water use for refuge lands south of State Line 

Road, which are served by the Project water deliveries, was 

approximately 89,000 acre-ft.

To estimate needed annual water deliveries for the 

refuge, estimated annual water use was reduced by annual 

precipitation and adjusted for salinity flushing. For water years 

2003, 2004, and 2005, annual precipitation, measured nearby 

at the BOR AgriMet station in Worden, Oregon (WRDO), 

near the northwestern corner of the refuge, was 10.1, 8.4, and 

10.6 in., respectively (Bureau of Reclamation, 2004). Needed 

annual water deliveries for each of the three main refuge 

lands (Project, Area K, non-Project) are shown in table 3. The 

needed mean annual water delivery for the entire refuge for 

the 3-year period was estimated to be 107,000 acre-ft. 

Tule Lake Refuge

The total number of acres by sump and by land-use 

category for the Tule Lake refuge for 2003, 2004, and 2005 

are shown in table 4. Because the cumulative size of each 

land-use category continually changes, a better representation 

of recent conditions can be made using the last 3 years of data 

instead of just 2005. Acreage data for each of the land-use 

categories are from the annual USFWS habitat plans for the 

refuge. The total number of acres each year for each sump and 

the sum of all the sumps are not necessarily the same each 

year. Differences can be attributed to mapping error or to small 

units that were included or not included in the habitat plan for 

a given year. The total number of acres shown also does not 

include all refuge property. Small, noncontiguous units; the 

Area J unit; and narrow upland strips located along the borders 

of Sumps 1A, 1B, and 2 were not included because they do not 

receive Project water.

Sump 1A was managed as a permanent wetland in all 

3 years. Approximately 10 percent of the unit was defined 

as emergent vegetation and the remaining 90 percent as 

open water (Tim Mayer, U.S. Fish and Wildlife Service, 

Portland, Oregon, oral commun., 2005). To estimate water 

use in the sump, the annual rates of emergent-vegetation 

Land-use category

Water use (acre-feet)

Project Area K Non-project Total

2003 Habitat Plan

Grain 9,028 15,979 0 25,008

Seasonal wetland 43,477 600 22,382 66,459

Emergent vegetation 14,182 0 0 14,182

Open water 18,260 0 0 18,260

Total water use 84,947 16,580 22,382 123,909

Precipitation -24,030 -5,564 -6,509 -36,103

Water delivery 60,917 11,015 15,873 87,806

 Total 73,101 13,218 19,048 105,367

2004 Habitat Plan

Grain 15,760 15,978 0 31,738

Seasonal wetland 45,968 600 16,446 63,014

Emergent vegetation 14,201 0 0 14,201

Open water 18,281 0 0 18,281

Total water use 94,209 16,578 16,446 127,233

Precipitation -22,486 -4,630 -3,979 -31,094

Water delivery 71,723 11,948 12,467 96,138

 Total 86,068 14,338 14,960 115,366

2005 Habitat Plan

Grain 12,835 15,881 0 28,716

Seasonal wetland 41,218 520 15,452 57,190

Emergent vegetation 15,516 0 0 15,516

Open water 18,232 0 0 18,232

Total water use 87,800 16,401 15,452 119,654

Precipitation -26,333 -5,786 -4,721 -36,840

Water delivery 61,467 10,615 10,732 82,814

 Total 73,761 12,738 12,878 99,377

2005 Habitat Plan

Total water use 88,986 16,520 18,093 123,599

Adjusted water 

delivery

77,643 13,431 15,629 106,703

Table 3. Estimated water use in the Lower Klamath National Wildlife 

Refuge, Oregon and California, 2003-2005.

[Project, lands south of State Line Road irrigated by Bureau of Reclamation 

Project; Area K, Area K leased lands and all other units north of State Line 

Road; Non-Project, lands south of State Line Road not irrigated with Project 

water. Water-use categories are based on annual rates in table 1. Adjusted 

water delivery is the estimated water delivery plus additional water for salinity 

flushing. Source: Tim Mayer, U.S. Fish and Wildlife Service, Portland, 

Oregon, written commun., 2005]

The main area of the refuge, south of State Line Road, 

contains a mix of land-use categories. Most of these units 

are managed as seasonal wetlands. However, some units are 

permanent open-water wetlands, and other units are leased 

for grain production. With the exception of permanent openwater units, many units in the refuge change from one land 

use to another on an annual basis. Table 3 shows water-use 

estimates for the Lower Klamath refuge derived by using 

 Water-Use Estimates and Flow Data for the Lower Klamath and Tule Lake National Wildlife Refuges, OR and CA
Land-Use Category

Area (acres)

Sump

1A

Sump

1B

Sump

2

Sump

3 Total

2003 Habitat Plan

Grain 0 0 6,131 10,903 17,034

Seasonal wetland 0 3,326 278 643 4,246

Emergent vegetation 929 0 0 381 1,311

Open water 8,363 0 0 381 8,744

 Total 9,292 3,326 6,409 12,309 31,335

2004 Habitat Plan

Grain 0 0 6,409 10,885 17,294

Seasonal wetland 0 0 0 528 528

Emergent vegetation 929 831 0 435 2,196

Open water 8,363 2,494 0 435 11,292

 Total 9,292 3,326 6,409 12,284 31,310

2005 Habitat Plan

Grain 0 0 6,409 10,589 16,998

Seasonal wetland 0 0 0 267 267

Emergent vegetation 929 832 0 751 2,512

Open water 8,363 2,495 0 751 11,608

 Total 9,292 3,326 6,409 12,358 31,385

Table 4. Area of land in different land-use categories in the Tule Lake 

National Wildlife Refuge, Oregon and California, 2003–2005.

[Some small, noncontiguous units of refuge property, Area J unit, and 

narrow upland units located along the borders of Sumps 1A, 1B, and 2 are 

not included. Source: Tim Mayer, U.S. Fish and Wildlife Service, Portland, 

Oregon, written commun., 2005]

Land-Use Category

Water use (acre-feet)

Sump 

1A

Sump 

1B

Sump 

2

Sump 

3 Total

2003 Habitat Plan

Grain 0 0 15,328 27,257 42,585

Seasonal wetland 0 9,644 805 1,865 12,314

Emergent vegetation 2,444 0 0 1,003 3,447

Open water 34,037 0 0 1,552 35,589

Total water use 36,480 9,644 16,132 31,678 93,935

Precipitation -8,069 -2,888 -5,565 -10,688 -27,209

Water delivery 28,412 6,757 10,568 20,990 66,726

Adjusted water 

delivery

34,094 8,108 12,681 25,188 80,071

2004 Habitat Plan

Grain 0 0 16,022 27,275 43,297

Seasonal wetland 0 0 0 1,533 1,533

Emergent vegetation 2,444 2,187 0 1,144 5,775

Open water 34,037 10,152 0 1,771 45,959

Total water use 36,480 12,338 16,022 31,723 96,563

Precipitation -5,722 -2,048 -3,947 -7,565 -19,282

Water delivery 30,758 10,290 12,075 24,158 77,281

Adjusted water 

delivery

36,910 12,348 14,490 28,990 92,738

2005 Habitat Plan

Grain 0 0 16,023 26,472 42,494

Seasonal wetland 0 0 0 774 774

Emergent vegetation 2,444 2,187 0 1,975 6,606

Open water 34,037 10,153 0 3,057 47,246

Total water use 36,480 12,339 16,023 32,278 97,120

Precipitation -10,121 -3,623 -6,980 -13,460 -34,183

Water delivery 26,360 8,717 9,042 18,818 62,937

Adjusted water 

delivery

31,632 10,460 10,850 22,582 75,524

2003-2005 Averages

Total water use 36,480 11,441 16,059 31,893 95,873

Adjusted water 

delivery

34,212 10,306 12,674 25,586 82,778

Table 5. Estimated water use in the Tule Lake National Wildlife Refuge, 

Oregon and California, 2003-2005.

[Water-use categories are based on annual rates shown in table 1; “Adjusted 

water delivery” is the estimated water delivery plus additional water for 

salinity flushing. Source: Tim Mayer, U.S. Fish and Wildlife Service, 

Portland, Oregon, written commun., 2005]

evapotranspiration (2.63 ft) and open-water evaporation (4.07 

ft) were applied to their associated portions of the sump for 

each year. The 3-year average water use in the sump was 

approximately 36,500 acre-ft (table 5).

All of Sump 1B was managed as permanent, openwater wetland in 2003. However, in 2004–2005, the sump 

was managed as both a seasonal and permanent wetland. 

Appropriate rates shown in table 1 were used to compute 

water use for each year. To estimate 2004–2005 water use, the 

annual emergent-vegetation-evapotranspiration rate (2.63 ft) 

was applied to 25 percent of the sump and the annual openwater evaporation rate (4.07 ft) was applied to the other 75 

percent of the area. The 3-year mean annual water use in 

Sump 1B was approximately 11,400 acre-ft.

The 3-year mean annual water use in Sumps 2 and 3 was 

approximately 16,000 and 31,900 acre-ft, respectively. Most 

of Sumps 2 and 3 are managed for grain. Water use in these 

units was based on the annual evapotranspiration rate of 2.5 ft. 

However, Sumps 2 and 3 also contain seasonal and permanent 

wetlands, which change in area from year to year. Water use 

for those units was computed using the annual rates shown in 

table 1. Because the permanent wetland units in these sumps 

are much shallower than Sump 1A, a 1:1 ratio of emergentvegetation and open-water rates was applied to these units.

Water-Use Estimates Based on Open-Water Evaporation and Evapotranspiration Losses 
The 3-year mean annual water-use volume for the 

entire refuge, including seasonal-wetland, open-water, and 

agricultural water use, was approximately 95,900 acre-ft 

(table 5). To estimate needed annual water deliveries for the 

refuge, estimated annual water use was reduced by annual 

precipitation. For water years 2003, 2004, and 2005, annual 

precipitation, measured at the nearby Tule Lake Agricultural 

Station in Tule Lake, California, was 10.4, 7.4, and 13.1 in., 

respectively (California Department of Water Resources, 

2005). After subtracting precipitation from the water-use 

volumes, 20 percent was added to account for salinity 

flushing. The estimated needed water deliveries for each of 

the sumps are shown in table 5. The needed mean annual 

water delivery for the entire refuge for the 3-year period was 

estimated as about 82,800 acre-ft.

Uncertainty in Open-Water Evaporation and 

Evapotranspiration Estimates

Various factors contribute uncertainty in estimating wateruse and water-delivery needs based on open-water evaporation 

and evapotranspiration estimates. The accuracy of the 

evaporation and evapotranspiration estimates described earlier 

could be improved if pan evaporation data were collected at 

both refuges. The rates presented herein are based on average 

conditions. In reality, evaporation and evapotranspiration 

rates vary from year to year. The rates presented in this report 

also are based on evaporation and air temperature data that 

were not collected in recent years nor are local to the refuges. 

The open-water evaporation rate is based on pan evaporation 

data collected from 1956 to 1981. Wind conditions also 

significantly affect evaporation and evapotranspiration rates. 

As a result, evaporation and evapotranspiration rates can vary 

among different locations within the two refuges because of 

geographic variation in wind conditions. Overall accuracy of 

the evapotranspiration estimates also could be improved with 

specific evapotranspiration rates for different types of grain 

vegetation in the refuge. However, acquiring more specific 

crop information was not possible within the scope and 

timeline of this project.

Adjusting needed water deliveries to account for salinity 

flushing over time introduces additional uncertainty. The 

salinity factor used in the study was based on measured 

specific conductance data collected at various locations within 

and surrounding the refuges. However, specific conductance 

levels vary with location and with seasonality. 

Water-Use Estimates Based on Inflows 

and Outflows

Measured inflows to and outflows from the refuges 

were used to make a separate estimate of refuge water use for 

comparison with those based on evapotranspiration estimates. 

Project inflows include all water originating from the Project 

that is drained or pumped into both the Tule Lake and Lower 

Klamath refuges. 

Lower Klamath Refuge

Mean annual Project inflows to and outflows from the 

Lower Klamath refuge for 2003–2005 are based on measured 

flow data collected at D Pumping Plant, Ady Canal at State 

Line Road, and the Klamath Straits Drain at State Line Road. 

For water years 2003–2005, the combined mean annual inflow 

into the refuge through D Pumping Plant and from the Ady 

Canal was approximately 89,000 acre-ft, and mean annual 

outflow through the Klamath Straits Drain was approximately 

15,300 acre-ft (table 6). The resulting net inflow was 

approximately 73,700 acre-ft. This amount is comparable to 

the estimated needed water delivery of approximately 77,600 

acre-ft for the non-Area K refuge units located south of State 

Line Road that are irrigated by Project water.

Mean annual net inflow to the Lower Klamath refuge 

was approximately 49,800 acre-ft for 1962–2005 in contrast to 

about 73,700 acre-ft for 2003–2005 (table 7). Although mean 

April–September net inflows for 1962–2005 and 2003–2005 

have remained fairly constant, mean October–March net 

inflow has increased considerably for 2003–2005. Increased 

flow deliveries during the autumn and winter since the mid1980s reflect a significant change in refuge management, as 

more units have been managed as seasonal wetlands than in 

the 1960s and 1970s (fig. 3). In water years 1963, 1973, and 

1984, there was no net inflow during the winter months of 

October–March, because more water was draining out of the 

refuge than was being pumped in. In the summer of water 

year 1965, there also was no net inflow of water to the refuge. 

Because of severe flooding in the previous October, the refuge 

already had saturated conditions and less water delivery was 

required.

Changes in the management of both refuges also can be 

observed in figure 4, which are graphs of monthly flows from 

1961 through 2005 for Ady Canal, Klamath Straits Drain, 

10 Water-Use Estimates and Flow Data for the Lower Klamath and Tule Lake National Wildlife Refuges, OR and CA
and D Pumping Plant. Figure 4A shows an increase in flow 

deliveries to the Lower Klamath refuge during the fall and 

winter since the late 1980s. During this period, flows also 

decreased in the Klamath Straits Drain (fig. 4B). Both these 

trends are a reflection of the increase in the number of units 

that were flooded in the autumn and winter and managed 

as seasonal wetlands. Beginning in the early 1990s, more 

water was held in Sumps 1A and 1B to maintain a minimum 

elevation under ESA guidelines for sucker habitat protection. 

This change in management is seen in figure 4C. Significantly 

less water was pumped out of the sumps in the 1990s than 

during October–December in the three earlier decades. It 

also is possible to discern historical wet and dry periods 

from figures 4A-4C. During wet years, such as 1965, 1984, 

and the late 1990s, there is some correspondence between 

the D Pumping Plant and Klamath Straits Drain flows. More 

water is pumped through the D Pumping Plant to drain the 

Tule Lake sumps, and much of that water then passes through 

the Lower Klamath refuge. In dry years, such as 1981 and the 

early 1990s, more water deliveries were made through the Ady 

Canal (fig. 4A). 

Tule Lake Refuge

Most of the Project water is delivered to the Tule Lake 

refuge via the N Canal, Lost River, and numerous pumped 

inflows. Although there are no permanent flow gages on 

these canals or on the Lost River at locations near the refuge 

boundaries, some estimates of flow into the refuge by way 

of these waterways can be derived from a USFWS surfacewater budget analysis of the refuge sumps. Mean annual 

inflows from the N Canal, Lost River, and miscellaneous 

pumped inflows were estimated to be approximately 46,100, 

24,600, and 81,300 acre-ft, respectively (table 6). The USFWS 

analysis of Sump 1A and 1B had a deficit between surfacewater inflow and outflow of approximately 30,300 acre-ft/yr. 

This amount includes surface-water-flow measurement error 

as well as probable unmeasured ground-water flow. Because 

there is an eastward ground-water head gradient along the 

western margin of the refuge, it is likely that there is some 

seepage entering Sump 1A and 1B from the Lower Klamath 

refuge and BOR Project lands to the west. The same USFWS 

analysis also showed a surplus between surface-water inflow 

Lower Klamath National Wildlife Refuge

Inflow (acre-feet per year)

D Pumping Plant 59,606

Ady Canal 29,434

Outflow (acre-feet per year)

Klamath Straits Drain -15,338

Comparison of net inflow to water delivery

Net inflow 73,703

Water delivery1 77,643

Tule Lake National Wildlife Refuge

Inflow (acre-feet per year)

N Canal 46,140

Lost River 24,600

Sump 1A and 1B inflows 81,250

Net ground-water inflow 19,000

Outflow (acre-feet per year)

D Pumping Plant outflow -59,606

N Canal -35,300

Comparison of net inflow to water delivery

Net inflow 76,084

Water delivery2 82,778

1

Estimated needed water delivery for refuge areas south of State Line Road, 

table 3.

2

Estimated needed water delivery for entire refuge, table 5.

Table 6. Estimated 2003-2005 mean annual inflows to and outflows 

from the Lower Klamath and Tule Lake National Wildlife Refuges, Oregon 

and California.

[Lower Klamath National Wildlife Refuge: Average of 2003-2005 annual 

flows (Source: Jon Hicks, Bureau of Reclamation, Klamath Falls, Oregon, 

written commun., 2005). Tule Lake National Wildlife Refuge: Flows based 

on 1989-1999 period except for D Pumping Plant]

Mean net inflows (acre-feet per year) 1962–2005 2003–2005

Annual 49,819 73,703

October through March 19,583 40,458

April through September 30,236 33,245

Table 7. Mean net inflows to the Lower Klamath National Wildlife 

Refuge, Oregon and California, 1962-2005 and 2003-2005.

[Calculated as D Pumping Plant and Ady Canal flows minus Klamath Straits 

and 25 percent of P Canal flows]

Water-Use Estimates Based on Inflows and Outflows 11
and outflow from Sump 3 of approximately 11,300 acre-ft/yr. 

Ground-water flow from the southern part of the Tule Lake 

subbasin is consistent with hydraulic head data as well as 

historical accounts. The surface-water balance for the entire 

refuge had a deficit of approximately 19,000 acre-ft/yr. This 

amount includes both surface-water-flow measurement error 

and probable unmeasured ground-water flow. As stated 

earlier, the proportion attributed to surface-water measurement 

error versus the proportion attributed to ground-water flow 

is unknown. Most surface-water outflow from the refuge is 

through the D Pumping Plant and the N Canal. Estimated 

annual flow through the D Pumping Plant and the N Canal 

was approximately 59,600 and 35,300 acre-ft, respectively. 

0

10

20

30

40

50

60

70

80

90

100

1962196419661968197019721974197619781980198219841986198819901992199419961998200020022004

FLOW, IN THOUSAND ACRE-FEET

October to March

April to September

Figure 3. Lower Klamath National Wildlife Refuge net inflow, Oregon and California, 1962–2005.

Calculated as D Pumping Plant and Ady Canal flows minus Klamath Straits flows.

Subtracting the sum of estimated surface-water outflows from 

the sum of estimated surface-water inflows and net groundwater inflow results in an annual net surface-water inflow to 

the refuge of approximately 76,100 acre-ft. This volume is 

consistent with the estimated needed water delivery total of 

82,800 acre-ft shown in table 5 on the basis of open-water 

evaporation and evapotranspiration estimates. However, 

both methods of estimating water use, using evaporation and 

evapotranspiration estimates or inflows and outflows, have a 

wide range of uncertainty. Evaporation and evapotranspiration 

rates represent only average conditions, whereas much of 

the Tule Lake refuge inflow and outflow data were based 

on miscellaneous (rather than continuously monitored) flow 

measurements.

12  Water-Use Estimates and Flow Data for the Lower Klamath and Tule Lake National Wildlife Refuges, OR and CA
Figure 4. Monthly flows for Ady Canal, Klamath Straits Drain, and D Pumping Plant, Lower Klamath and Tule Lake 

National Wildlife Refuges, Oregon and California, 1961 through 2005.

sir2005-5036_fig04.ai

A. Ady Canal at State Line Road, water years 1961-2005

B. Klamath Straits Drain at State Line Road, water years 1961-2005

C. D Pumping Plant, water years 1962-2005

WATER YEAR

19611963196519671969197119731975197719791981198319851987198919911993199519971999200120032005

19611963196519671969197119731975197719791981198319851987198919911993199519971999200120032005

1963196519671969197119731975197719791981198319851987198919911993199519971999200120032005

JUNE

APR

FEB

DEC

OCT

AUG

JUNE

APR

FEB

DEC

OCT

AUG

JUNE

APR

FEB

DEC

OCT

AUG

Flow, in

thousand

acre-feet

per month

9

6

3

0

12

Flow, in

thousand

acre-feet

per month

12

8

4

0

20

16

Flow, in

thousand

acre-feet

per month

12

8

4

0

20

16

Water-Use Estimates Based on Inflows and Outflows 13
Refuge Water Budgets

Water budgets that approximate 2003–2005 conditions 

as much as possible for both refuges shown in figure 5 are 

based on the combination of annual water-use estimation using 

acreages and open-water evaporation and evapotranspiration 

estimates (tables 1–5) and measured inflows and outflows 

to and from the refuges (table 6). The percentages shown in 

figure 5 pertain to the budgets for each refuge separately; that 

is, they are relative to the total for each refuge. For example, 

21 percent of all water entering the Lower Klamath refuge is 

from precipitation and only 13 percent of all water entering 

the Tule Lake refuge is from precipitation. However, this 

does not mean that more precipitation falls on the Lower 

Klamath refuge than the Tule Lake refuge; it simply indicates 

that precipitation accounts for more of the water entering 

the Lower Klamath refuge than the Tule Lake refuge. The 

2003–2005 mean annual precipitation for both refuges is 

actually similar. Likewise, evapotranspiration loss for the 

Lower Klamath refuge constituted a much greater percentage 

of the water leaving the refuge compared with the Tule Lake 

refuge. However, the actual evapotranspiration rates were the 

same for both refuges.

Gaged flows that were used in the budget calculations for 

figure 5, such as those for D Pumping Plant, Ady Canal, and 

the Klamath Straits Drain, were from the 2003–2005 period. 

However, inflows and outflows for the Tule Lake refuge were 

derived from a USFWS water budget analysis of the refuge 

(Tim Mayer, U.S. Fish and Wildlife Service, Portland, Oregon, 

written commun., 2005). More recent flow data for those 

locations were either unavailable or not easily obtainable.

Ground-water fluxes in and out of the refuges are shown 

with dashed lines because they are unknown and cannot be 

discriminated from measurement error. The value shown for 

ground-water inflows and outflows and measurement error 

in the Tule Lake refuge were derived from residual terms in 

the USFWS water budget analysis (Tim Mayer, U.S. Fish and 

Wildlife Service, Portland, Oregon, written commun., 2005). 

Natural runoff into the Lower Klamath refuge from Sheepy, 

Cottonwood, and Willow Creeks were based on estimates 

from Wood (1960).

ET (47%)

ET (74%)

Precipitation

(21%)

Ady Canal (25%)

Straits Drain (9%)

D Pump

(30%)

N canal (17%)

Lost River

(12%)

Pumped

inflows (39%)

N canal (22%)

D Pump

(36%) Lower Klamath 

National Wildlife

Refuge

Tule Lake National 

Wildlife Refuge

Precipitation

(13%)

Sheepy

Creek (3%)

Willow

Creek (10%)

Cottonwood

Creek (5%)

GW flow/

SW error

(17%)

GW flow/

SW error

(6%)

GW flow/

SW error

(14%)

Figure 5. Water budget, derived from an approximation of 2003–2005 conditions, for Lower Klamath and Tule Lake National Wildlife Refuges, 

Oregon and California.

Percentages pertain to either inflows or outflows for each refuge. ET=combined open-water evaporation and evapotranspiration; 

GW=ground water, and SW=surface water. Ground-water flow through the refuges as shown in the diagram is consistent with measured groundwater elevation data in the region. However, percentages assigned to the ground-water fluxes are based on residuals from surface-water budget 

analyses. The residuals are a result of both probable unmeasured\ground-water flow and surface-water flow measurement error.

14  Water-Use Estimates and Flow Data for the Lower Klamath and Tule Lake National Wildlife Refuges, OR and CA
Ady Canal at State Line Road

The Ady Canal structure at State Line Road consists of 

four Waterman 48” circular canal gates. The two east gates 

divert water to Unit 2 in the refuge and generally are open. 

The two west gates divert water through pipes to Unit 5a 

and the Sheepy West unit, and generally are closed from 

April–September. Upstream and downstream water levels are 

measured by two staff plates. The plates generally are read on 

a weekly basis, or whenever the gate openings are changed 

by USFWS or BOR technicians. Flows are computed using a 

modified version of the Waterman gate flow equation. Input 

variables to the equation are the gate opening and the head 

difference between the upstream and downstream water levels.

In 2000, the USFWS made a series of check 

measurements at the site on the downstream side of State 

Line Road. (Check measurements are direct measurements 

of flow that are used to verify the accuracy of flow estimates 

made with the use of rating curves or other indirect methods.) 

The USFWS made an additional check measurement on 

September 12, 2005. Measured flow was 115 ft3/s. With the 

measurements, it was possible to construct a relation between 

the flow measurements and estimated flows using a canal 

gate equation (Tim Mayer, U.S. Fish and Wildlife Service, 

Portland, Oregon, written commun., 2005). 

The USGS made a check measurement at this site on 

August 24, 2005, on the south side of State Line Road using 

an acoustic Doppler current profiler. Measured flow was 

123 ft3/s. The flow computed from the USFWS canal gate 

equation using a gate opening of 18 in. and head difference of 

3.4 ft at the time of the measurement was 135 ft3/s, which is 

an overestimation of approximately 10 percent. 

Diversion flow gages Ratings

Canal/River Location USGS 

(percent)

Cal Poly 

(percent)

Ady Canal State Line Road, OregonCalifornia>15 35

Klamath Straits 

Drain

State Line Road, OregonCalifornia>15 na

D Pumping 

Plant

Sump 1A, Tule Lake 

National Wildlife Refuge, 

California

>15 25

Table 8. Accuracy ratings for Ady Canal, Klamath Straits Drain, and 

D Pumping Plant flow records, Oregon and California. 

[Ratings: USGS, Based on water year 2005 record; Cal Poly, Based on 

water year 1999 and 2000 records. Both ratings are defined as the percent 

error within true flow of 95 percent of daily flows. Abbreviations: USGS, 

U.S. Geological Survey; Cal Poly, California Polytechnic State University 

Irrigation Training and Research Center; na, not available. >, greater than]

Flow Data Quality

The main flow channels entering and leaving the refuges 

that have been continuously monitored are the Ady Canal at 

State Line Road, Klamath Straits Drain at State Line Road, 

and D Pumping Plant on the edge of Tule Lake Sump 1A. 

Monthly records for all three sites go back as far as 1962 in 

the BOR hydrologic database. The accuracy and quality of the 

measurements and the records were assessed because of their 

importance in determining refuge water use.

Accuracy of the Records

Flow data collection at these three sites is serviced by the 

BOR, USFWS, Klamath Drainage District, and TID. Overall 

flow-record documentation for these sites is limited, as the 

records have not been compiled, reviewed, and published on 

an annual basis. It was not possible to document how every 

flow record value was computed. Annual station analyses for 

the sites were nonexistent. (Recently, however, the USFWS 

has improved flow-measurement accuracy at the Ady Canal 

site.) Daily values at all three sites were not computed from 

unit (hourly) values. Although continuous strip charts were 

used at the Klamath Straits Drain site to estimate head 

differences, only a single head difference value was taken 

(manually) from the charts for each day.

The rating the USGS uses to describe the accuracy of 

an annual streamflow record depends on (1) the stability of 

the stage-discharge relation or, if the control is unstable, the 

frequency of discharge measurements and (2) the accuracy 

of measurements of stage, measurements of discharge, 

and interpretation of records (Herrett and others, 2004). 

An “Excellent” rating indicates that about 95 percent of 

the daily discharges are within 5 percent of the true value. 

A “good” and “fair” rating indicates that about 95 percent 

of the daily discharges are within 10 and 15 percent of the 

true value, respectively. Records that are considered to be 

less accurate are rated “poor.” Different accuracies may be 

assigned to different parts of a record. Because the USGS 

flow-record rating is applied to a record on an annual basis, 

it can be changed from year to year. For this assessment, 

the ratings, presented in the following sections for each of 

the flow gages, also were based on current conditions of 

the instrumentation, record compilation methods, and the 

existence of documentation regarding how every daily value 

was computed. Accuracy ratings for the three sites are shown 

in table 8. In addition to USGS ratings, accuracy ratings that 

were assessed by the California Polytechnic State University 

Irrigation Training and Research Center are also shown (Burt 

and Freeman, 2003).

Flow Data Quality 15
To rate the current flow record for the Ady Canal site, 

various factors were considered. The most critical factor is 

that there is no continuously operating instrumentation at this 

site. Data are acquired by reading staff plates. However, in 

examining records in the BOR office in Klamath Falls, there 

was no evidence that the staff plates and gate openings were 

read and recorded on a daily basis; nonetheless, individual 

daily flow computations using the equation were still made. 

This site also did not have ideal cross-section locations that 

are needed to make accurate check measurements. Because 

of these factors, this flow record was rated as “poor.” In other 

words, 95 percent of the daily flows could be in error by more 

than 15 percent. 

Klamath Straits Drain at State Line Road

The Klamath Straits Drain structure at State Line Road 

consists of three canal gates. Similar to the Ady Canal gates, 

flow is computed at this site using the gate openings and the 

upstream and downstream head difference. Unlike the Ady 

Canal site, there are two Stevens drum-type stage recorders 

mounted on stilling wells upstream and downstream of the 

gates. Continuous recorders make it possible to compute daily 

flows with more reliability. At the time of this study, flows 

at this location were close to zero, and it was not possible 

for the USGS to make a check measurement. It could not be 

determined when the last check measurement was made at this 

site and by what agency.

On the basis of most factors, this flow record could 

have been rated as “fair,” in which case 95 percent of the 

daily flows would have been defined as being within 10 to 15 

percent of true flow. However, the flow record for this site did 

not have adequate documentation of how each daily flow value 

was determined. For this reason, the flow record was rated 

as “poor,” indicating that 95 percent of the daily flow values 

could have been in error by more than 15 percent. 

D Pumping Plant

The D Pumping Plant has five pumps. Pumps 1, 2, and 3 

are rated by the manufacturer as having a pumping capacity of 

160 acre-ft/d (80.7 ft3/s), and pumps 4 and 5 have a pumping 

capacity of 142 acre-ft/d (71.6 ft3/s) (Ron Fensler, Tulelake 

Irrigation District, Tulelake, California, oral commun., 2005). 

Although the plant was constructed in the 1940s, most of the 

pumps have been replaced or retooled since that time. Daily 

flow estimates are made by keeping a daily record of the 

number of pumps in operation and their duration of operation.

On August 3, 2005, the USGS made a flowmeter check 

measurement of the D Pumping Plant by measuring flow in 

the P Canal at Doris Brownell Road. Measured flow was 82 

ft3/s. However, upstream of the measurement, approximately 

1,800 gal/min (about 4 ft3/s) was being pumped out of the 

canal to a farm field. Without that withdrawal, the flow would 

have been approximately 86 ft3/s. The flow measurement was 

rated “fair,” which for individual flow measurements (unlike 

annual streamflow records discussed above) means that the 

measurement could have been off by 8 percent of true flow. 

Actual flow, then, might have been within the range of 75–89 

ft3/s. At the time of the measurement, TID was operating one 

pump continuously for several days. The USFWS also made 

check measurement at the same location on the P Canal on 

November 1, 2000, and measured 218 ft3/s. At the time of 

that measurement, three pumps were operating. BOR records 

for that date reported a flow of 436 acre-ft/d (220 ft3/s) at D 

Pumping Plant.

Similar to the Klamath Straits Drain flow record, this 

flow record also could have been rated “fair.” However, the 

flow record for this site did not have adequate documentation 

of how each daily flow value was determined. For this reason, 

the flow record was rated “poor,” indicating that 95 percent of 

the daily flows could be in error by more than 15 percent.

Suggested Improvements to the Flow-DataCollection Network

In recent years, the need for more accurate flow 

measurements of water entering and leaving both the 

Lower Klamath and Tule Lake refuges has become 

apparent. Following are improvements that could be made 

to the data-collection network to increase the accuracy 

of flow measurements. The USGS is aware that some of 

these improvements already are planned through current 

collaboration between the BOR and the Irrigation Training and 

Research Center of California Polytechnic State University.

Coordination

Data consistency, management, storage, and retrievals 

would be improved if all refuge boundary flow data collection 

efforts were performed by a single agency, either the BOR, 

USFWS, or USGS. All flow records, both past and future, 

would be archived by and stored at the offices of a single 

agency.

Documentation

Proper documentation of all aspects of flow-data 

collection is essential for maintaining a high-quality datacollection program. It requires the maintenance of an archive 

for each data-collection site that includes hourly stage values, 

rating curves, check measurements, stage shifts, rating shifts, 

and stage measurements, which can be used to recreate any or 

all of the published daily flow record if necessary.

16  Water-Use Estimates and Flow Data for the Lower Klamath and Tule Lake National Wildlife Refuges, OR and CA
Equipment Modernization

Digital data loggers are more accurate and reliable than 

strip-chart stage recorders, which were originally developed in 

the 1930s. The Klamath refuge data collection program would 

be much enhanced by the installation of digital data loggers 

with real-time telemetry at the Klamath Straits Drain flow site, 

Ady Canal at State Line Road site, the D Pumping Plant, and 

possible new sites.

Check Measurements

Check measurements help verify the accuracy of the flow 

record at data-collection sites. Depending on the stability of a 

stream’s channel bed, USGS protocol stipulates that a check 

measurement be made at each site generally every 3 months. 

Check measurements made with the same frequency at refuge 

boundary flow sites would provide a degree of confidence in 

the quality of the data that would not be possible without such 

measurements.

Additional Flow Sites

The main flow channels near or at the boundary of the 

Lower Klamath refuge (Ady Canal, D Pumping Plant, and 

Klamath Straits Drain) already are gaged. However, periodic 

flow measurements at Sheepy, Cottonwood, and Willow 

Creeks would increase the accuracy of inflow estimates 

because the cumulative flow of these streams, approximately 

14 percent of inflow to the refuge, is significant.

To further improve the measurement of flow into the 

Tule Lake refuge, the BOR and/or the USFWS could install 

a streamflow gage on the Lost River near the entrance of 

the refuge, if it is feasible. Another possible site for a gage 

would be at the main points where Project water enters the 

N Canal. Most of the N Canal water is used to service Sump 3. 

However, unlike the Lower Klamath refuge, flow comes 

into the Tule Lake refuge at many locations. Flows at many 

of those locations may still have to be estimated, because 

establishing flow gages would not be practical.

Summary and Conclusions

Demand for water in the semiarid upper Klamath Basin 

of southern Oregon and northern California has increased in 

recent years, resulting in the need to better quantify water 

availability and use in and around the Bureau of Reclamation 

Klamath Project. Most of the water entering the Lower 

Klamath and Tule Lake National Wildlife Refuges originates 

from the Project. In 2005 the Bureau of Reclamation asked 

the U.S. Geological Survey Oregon Water Science Center to 

evaluate and better quantify water use and flow data to and 

from the refuges.

Located south of the Project and mostly in California, 

the Lower Klamath and Tule Lake refuges encompass 

approximately 46,700 and 39,100 acres, respectively. Roughly 

one-third of the combined refuge surface areas are leased 

to farmers for cereal grain and alfalfa production. Since the 

early 1900s, surface-water flow to and from the refuges has 

developed into a highly regulated system.

The Lower Klamath refuge receives most of its water 

from the D Pumping Plant via a tunnel under Sheepy Ridge, 

Ady Canal, and precipitation. Additional, smaller quantities of 

water enter the refuge from springs that supply flow to Sheepy, 

Willow, and Cottonwood Creeks. Most of the water leaves the 

refuge through open-water evaporation, evapotranspiration 

from vegetated wetlands, and the Klamath Straits Drain. Water 

is pumped through the Klamath Straits Drain into the Klamath 

River.

Water enters the Tule Lake refuge from Project returnflow canals, the Lost River, the N Canal, precipitation, and 

ground-water seepage. Water leaves the refuge through the D 

Pumping Plant, open-water evaporation, evapotranspiration 

from vegetated wetlands, and ground-water seepage. The Tule 

Lake refuge is composed of four major sumps, which include 

Sumps 1A, 1B, 2, and 3. Sumps 1A and 1B usually are yearround open-water bodies, whereas Sumps 2 and 3 usually are 

leased for agriculture. 

Annual water-use estimates for the refuges were 

computed using separate open-water evaporation and 

evapotranspiration rates and acreage for four land-use 

categories. On the basis of local climate data and data from 

previous studies, the estimated combined annual open-water 

evaporation and evapotranspiration rates for grain fields, 

seasonal wetlands, emergent vegetation wetlands, and openwater bodies were, for this study, 2.5, 2.9, 2.63, and 4.07 ft, 

respectively. Total water use was estimated as the sum of the 

products of each rate and the number of acres in its associated 

land-use category. Because the number of acres in each landuse category changes each year, total water use was computed 

separately for 2003, 2004, and 2005 and then averaged to 

approximate current conditions. Mean annual (2003–2005) 

water use for the Lower Klamath and Tule Lake and refuges 

was approximately 124,000 and 95,900 acre-ft, respectively. 

To estimate needed water deliveries for each refuge, annual 

precipitation for 2003, 2004, and 2005 was subtracted from 

the annual water use estimate for those years. Twenty percent 

of those totals was then added to the estimates to account 

for long-term salinity flushing over time. The 2003–2005 

mean annual estimated needed water deliveries for the Lower 

Klamath and Tule Lake refuges were 107,000 and 82,800 

acre-ft, respectively. 

Summary and Conclusions 17
Using estimated and measured surface-water inflows 

and outflows for 2003–2005, mean annual net inflow to 

the refuges was computed by subtracting outflows from 

inflows. Computed 2003–2005 mean annual net inflow for 

the Lower Klamath refuge was approximately 73,700 acre-ft. 

This volume was computed by subtracting flow at Klamath 

Straits Drain at State Line Road from the sum of D Pumping 

Plant and Ady Canal at State Line Road flows. However, that 

value can be compared only to estimated water use in refuge 

units located south of State Line Road served by Project 

water. The estimated needed water delivery for those units 

is approximately 77,600 acre-ft (in contrast to the estimated 

needed water delivery for the entire refuge of 107,000 acre-ft) 

and comparable to the mean annual net inflow estimate above. 

For the Tule Lake refuge, mean annual 2003–05 net inflow 

was approximately 76,100 acre-ft, which was comparable to 

the estimated annual needed water delivery of 82,800 acre-ft.

For 1962–2005, mean annual net inflow to the Lower 

Klamath refuge was approximately 49,800 acre-ft, about 

23,900 acre-ft less than for 2003–2005. Although mean 

April–September net inflows for 1962–2005 and 2003–2005 

have remained fairly constant, mean October–March net 

inflows were greater during 2003–2005 than during 1962–

2005. Increased autumn and winter flow deliveries starting 

in the mid-1980s reflected a significant change in refuge 

management: More units currently are managed as seasonal 

wetlands than were in the 1960s and 1970s.

Flow records for the Ady Canal at State Line Road, 

Klamath Straits Drain at State Line Road, and D Pumping 

Plant were evaluated for their data quality. On the basis of 

USGS flow-record criteria, all three flow records were rated as 

“poor.” By definition, 95 percent of the daily flows in a record 

having this rating could be in error by more than 15 percent. 

Improvement in the streamflow-data collection network 

at refuge boundary locations can be achieved through (1) data 

collection by a single agency—the Bureau of Reclamation, 

U.S. Fish and Wildlife Service, or U.S. Geological Survey, 

(2) better data documentation and archiving, (3) equipment 

modernization, (4) more frequent check measurements, and 

(5) new flow-measurement locations near the boundaries of 

both refuges.

Acknowledgments

The authors thank Tim Mayer, U.S. Fish and Wildlife 

Service, Portland, Oregon; Dave Mauser, U.S. Fish and 

Wildlife Service, Tulelake, California; Jon Hicks, Bureau of 

Reclamation, Klamath Falls; John Rasmussen, formerly with 

the Bureau of Reclamation, Klamath Falls, Oregon; and Beau 

Freeman, Irrigation Training and Research Center, California 

Polytechnic State University, San Luis Obispo, California, for 

their assistance in this study.

References Cited

Bureau of Reclamation, 2004 [revised], Pacific Northwest 

Cooperative Agricultural Weather Network (AgriMet), 

http://www.usbr.gov/pn/agrimet/monthlyet.html, accessed 

on August 19, 2005.

Burt, C., and Freeman, B., 2003, Klamath Basin 

investigation—Hydrologic assessment of the upper Klamath 

Basin, Issues and opportunities, Draft report, May 2003: 

San Luis Obispo, California, Irrigation Training and 

Research Center, California Polytechnic State University, 

274 p.

California Department of Water Resources, 2005, California 

Irrigation Management Information System (CIMIS): 

http://wwwcimis.water.ca.gov/cimis/data.jsp, accessed on 

September 12, 2005.

Dunne, T. and Leopold, L.B., 1978, Water in Environmental 

Planning: San Francisco, W. H. Freeman and Company, 

p. 101.

Gay, T.E., and Aune, Q.A., compilers, 1958, Geologic map 

of California—Alturas sheet, Olaf P. Jenkins edition: 

California Division of Mines and Geology, scale 1:250,000, 

2 sheets.

Herrett, T.A., Hess, G.W., House, J.G., Ruppert, G.P., and 

Courts, M.L., 2004, Water Resources Data, Oregon, Water 

Year 2004: U.S. Geological Survey Water Data Report 

OR–04–1, 996 p.

MacCoy, D.E., 1994, Physical, chemical, and biological data 

for detailed study of irrigation drainage in the Klamath 

Basin, California and Oregon, 1990–92: U.S. Geological 

Survey Open-File Report 93–497, 168 p.

Mayer, T., and Thomasson, R., 2004, Fall water requirements 

for seasonal diked wetlands at Lower Klamath National 

Wildlife Refuge: Wetlands, v. 24, no. 1, p. 92–103.

Oregon Water Resources Department, 1971, Klamath Basin: 

Salem, Oregon, 288 p.

Rieck, H.J., Sarna-Wojcicki, A.M., Meyer, C.E., and Adam, 

D.P., 1992, Magnetostratigraphy and tephrochronology of 

an upper Pliocene to Holocene record in lake sediments 

at Tulelake, northern California: Geological Society of 

America Bulletin, v. 104, no. 4, p. 409–428.

U.S. Fish and Wildlife Service, 2005, Klamath Basin 

National Wildlife Refuges Complex: http://www.fws.

gov/klamathbasinrefuges/history.html, accessed on October 

13, 2005.

Wood, P.R., 1960, Geology and ground-water features of the 

Butte Valley region, Siskiyou County, California: U.S. 

Geological Survey Water-Supply Paper 1491, 150 p.

18  Water-Use Estimates and Flow Data for the Lower Klamath and Tule Lake National Wildlife Refuges, OR and CA
Manuscript approved for publication, February 4, 2006

Prepared by the U.S. Geological Survey Publishing Network 

Publishing Service Center, Tacoma, Washington

Linda Rogers

Donita Parker

Bobbie Jo Richey

For more information concerning the research in this report, contact the

Director, Oregon Water Science Center 

10615 SE Cherry Blossom Drive

Portland, Oregon 97216

http://or.water.usgs.gov
Printed on recycled paper

SIR 2006–5036 An Evaluation and Review of Water-Use Estimates and Flow Data for the Lower Klamath and Tule Lake National Wildlife Refuges, Oregon and California Risley and Gannett