APPENDIX F-I.5 

Las Vegas Wash 

Huffman-Broadway Group, Inc.

Environmental Consultants

Investigation of the Presence of Wetlands and 

Other Waters of the United States 

DesertXpress Project 

HUC 8 Las Vegas Watershed

Clark County, Nevada 

July 2010

HBG

F-I.5-1
Prepared for

DESERTXPRESS ENTERPRISES, LLC

6750 Via Austi Parkway 

Suite 250 

Las Vegas, NV 89119 

By

HUFFMAN-BROADWAY GROUP, INC.

828 Mission Avenue 

San Rafael, CA 94901 

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TABLE OF CONTENTS

1.0 INTRODUCTION.......................................................................................................... 1

1.1 PROJECT PURPOSE AND SCOPE OF WORK ..................................................................................... 1

1.2 CONTACT INFORMATION .............................................................................................................. 2

1.3 STUDY AREA................................................................................................................................ 2

1.4 ENVIRONMENTAL SETTING ........................................................................................................... 2

1.4.1 Topography............................................................................................................................. 3

1.4.2 Land Use................................................................................................................................. 3

1.4.3 Geology and Soils................................................................................................................... 3

1.4.4 Biological Resources .............................................................................................................. 5

1.4.5 Climate ................................................................................................................................... 6

1.4.6 Hydrology............................................................................................................................... 6

2.0 REGULATORY FRAMEWORK................................................................................... 9

2.1 DEFINITION OF WETLANDS AND OTHER WATERS OF THE U.S....................................................... 9

2.2 LIMITS OF JURISDICTION............................................................................................................. 10

2.3 IDENTIFICATION OF ORDINARY HIGH WATER MARKS (OHWM)................................................ 10

2.4 WETLANDS DELINEATION CRITERIA ........................................................................................... 12

2.4.1 Wetland Hydrology............................................................................................................... 13

2.4.2 Hydric Soils .......................................................................................................................... 15

2.4.3 Prevalence of Wetland Vegetation........................................................................................ 18

3.0 DELINEATION METHOD ..........................................................................................21

3.1 OBJECTIVE AND ESTABLISHMENT OF STUDY AREA BOUNDARY ................................................. 21

3.2 STUDY AREA RECONNAISSANCE ................................................................................................ 21

3.3 WETLANDS IDENTIFICATION AND DELINEATION ......................................................................... 21

3.3.1 Dominance of Wetland Vegetation ....................................................................................... 22

3.3.2 Presence of Hydric Soil Indicators....................................................................................... 22

3.3.3 Presence of Wetland Hydrology Indicators.......................................................................... 22

3.4 IDENTIFICATION AND DELINEATION OF OTHER WATERS............................................................. 23

3.5 MAPPING.................................................................................................................................... 24

4.0 TECHNICAL FINDINGS ............................................................................................25

4.1 FIELD INDICATORS OF HYDRIC SOILS.......................................................................................... 25

4.2 FIELD INDICATORS OF WETLAND HYDROLOGY CONDITIONS ...................................................... 25

4.2.1 Field Indicators of Surface Flow.......................................................................................... 26

4.2.2 Landscape Features that Support Surface Flow................................................................... 27

4.2.3 Landscape Features with a Recognizable OHWM ............................................................... 28

4.3 FIELD INDICATORS OF WETLAND VEGETATION .......................................................................... 29

5.0 AREAS POTENTIALLY SUBJECT TO JURISDICTION ..........................................30

5.1 WETLANDS................................................................................................................................. 30

5.2 OTHER WATERS OF THE U.S. ...................................................................................................... 30

6.0 REFERENCES...........................................................................................................31

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LIST OF TABLES

Table 1a Potential Geomorphic Indicators of Ordinary High Water Marks for the 

Arid West

Table 1b Potential Vegetation Indicators of Ordinary High Water Marks for the 

Arid West

Table 2 Wetland Hydrology Indicators

Table 3 Wetland Hydrology Indicators for the Arid West

Table 4 Field Indicators of Hydric Soil Conditions

Table 5 Hydric Soil Indicators for the Arid West

LIST OF EXHIBITS

Exhibit A Figures

Figure 1 DesertXpress Project Alignment Alternatives

Figure 2 Location of Alignment Alternatives Within HUC-8 Watershed

Figure 3 Location of Study Area

Figure 4 Location of Study Area Within HUC-8 / HUC-12 Watersheds

Figures 5-12 Typical Examples of Field Indicators of Active Surface Water Flow and 

Ordinary High Water Marks Found Within Ephemeral Drainages Occurring 

Within the DesertXpress Project Study Area.

Figures 13-23 Examples of Drainages Found Within HUC-8 Watershed

Exhibit B Field Data 

Exhibit B1 Required Corps Waters Data Summary Table

Exhibit B2 Field Data

Exhibit C Maps of Potential Jurisdictional Areas

This report should be cited as: Huffman-Broadway Group, Inc. 2010. Investigation of the Presence of 

Wetlands and Other Waters of the United States, DesertXpress Project, HUC 8 Las Vegas Watershed, 

Clark County, Nevada. Prepared for DesertXpress Enterprises, LLC, Las Vegas, Nevada. July. 32 pp. plus 

Exhibits.

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1.0 INTRODUCTION

1.1 Project Purpose and Scope of Work

DesertXpress Enterprises, LLC (DXE) is proposing to construct and operate a dedicated 

two-tracked high speed passenger railway and associated operations and maintenance 

facilities between Victorville, California, and Las Vegas, Nevada (DesertXpress Project; 

Exhibit A, Figure 1). A Draft Environmental Impact Statement was issued for the project 

in March of 2009 and the Final EIS is nearing completion. A Supplemental Draft EIS has 

been prepared and will be issued shortly to address certain modifications to the proposed 

alignment and station locations made by the Applicant, DXE, in response to various 

comments made on the Draft. The U.S. Department of Transportation, Federal Railroad 

Administration (FRA) is the lead agency responsible for preparing the project 

Environmental Impact Statement (EIS).

In preparation for the permit phase of the project, DXE has retained Huffman-Broadway 

Group, Inc. (HBG) to investigate the presence of wetlands and other waters potentially 

subject to Corps and EPA regulation under Section 404 of the Clean Water Act (CWA) 

along the DesertXpress Project’s preferred and alternative alignments and study areas for 

the stations and ancillary facilities.

For the purpose of the jurisdictional delineation study, the proposed DesertXpress Project 

has been divided into six areas using the USGS HUC 8 1

This study was conducted in accordance with Code of Federal Regulations (CFR) 

definitions of jurisdictional waters, the Corps’ 1987 Wetlands Delineation Manual, the 

Corps’ 2008 Regional Supplement to the Corps of Engineers Wetland Delineation 

Manual: Arid West Region (Version 2.0), and supporting guidance documents. The 

remaining portions of Section 1.0 provide project contact information, describe the 

location of the Study Area and provide technical details regarding the general 

environmental conditions found within the Study Area, including relevant technical 

information from the Draft EIS regarding water resource data and biological and cultural 

resource information. Section 2.0 provides regulatory background information and 

details regarding the technical criteria and types of field indicators evaluated for during 

the study. Section 3.0 provides a detailed description of the methods used during this 

investigation. Section 4.0 provides a description of technical findings and Section 5.0 

level of watershed classification. 

The scope of this report is to evaluate the presence or absence of wetlands and waters 

potentially subject to Corps CWA jurisdiction within the proposed DesertXpress Project 

alignments and facilities located within HUC 8 Las Vegas Wash Watershed (Exhibit A, 

Figure 2).

1 HUC = U.S. Geological Survey (USGS) Hydrologic Unit Code. The Hydrologic Unit system is a standardized 

watershed classification system developed by USGS in the mid 1970s. Hydrologic units are watershed boundaries 

organized in a nested hierarchy by size. They range in size from national regions, to the smaller cataloging units 

(HUCs), which are roughly equivalent to local watershed.

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describes the types of areas found that potentially may be subject to Corps CWA 

jurisdiction. Section 6.0 is a Clean Water Act jurisdictional analysis using the Rapanos 

Guidance.

HBG is seeking, on behalf of DXE, a Preliminary Jurisdictional Determination pursuant 

to applicable Corps guidance documents. 

1.2 Contact Information

Project Owner Contact Applicant’s Agent & Wetland 

Regulatory Scientist

DesertXpress Enterprises, LLC

6750 Via Austi Parkway 

Suite 250 

Las Vegas, NV 89119 

Contact:

Tom Stone 

(702) 491-8940 

tstone@transmaxgroup.com

Huffman-Broadway Group, Inc 

828 Mission Avenue 

San Rafael, California 94901 

Contact:

Terry Huffman, Ph.D. 

(415) 925-2000 

thuffman@h-bgroup.com

1.3 Study Area

The Study Area for this investigation is defined as the area where potential ground 

disturbing components of the proposed project would occur based on the alternatives 

identified and analyzed in conjunction with the EIS and Supplemental EIS prepared for 

the DesertXpress Project. The Study Area encompasses the portion of the proposed 

DesertXpress Project alignment alternatives and facilities located within the HUC-8 Las 

Vegas Wash Watershed (15010015) from the town of Sloan, Nevada, to the Las Vegas 

terminal station, a distance of approximately 17.5 miles. The terminal will be designed to 

interface with extensions of the Las Vegas MonorailTM, with shuttles serving the resorts 

and the central business district (Exhibit A, Figure 3). 

1.4 Environmental Setting 

The Study Area encompasses those portions of the proposed DesertXpress Project 

alignments and facilities referred to in the Draft EIS as Segments 6 and 7 (together with a 

minor portion of Segment 5 Alternative 3B in the Town of Sloan HUC-12 watershed). 

The final alignment and facilities in Las Vegas have not been determined, but at the 

present time, Segment 6 will include the Interstate I-15 corridor from Sloan north to a 

central Las Vegas location. Segment 7 routing will likely depend on the selected location 

of the terminal station. 

HUC-12 watersheds in the Las Vegas Wash Watershed through which the proposed 

alignment alternatives and facilities passes are: 

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 Town of Sloan 

 Town of Arden 

 Duck Creek

 Tropicana Wash

 City of Las Vegas-Las Vegas Wash

Named drainages crossed by the project include Duck Creek, Tropicana Wash, and 

Flamingo Wash. These drainages flow east into Las Vegas Wash and ultimately to the 

Colorado River via Lake Mead. 

1.4.1 Topography

The Study Area is within the Basin and Range Geomorphic Province. The region is 

characterized by mountain ranges and hills of moderate relief that are partially buried and 

separated by broad alluviated basins. The Basin and Range province includes a large part 

of the southwestern United States. Elongate mountain ranges are separated by broad, 

nearly flat valleys. 

The proposed alignments and facilities in the Las Vegas Wash Watershed extend across 

alleviated areas in the Las Vegas Valley. From an elevation of approximately 2,700 feet 

msl in Sloan, Nevada, south of Las Vegas, the alignment alternatives descend to an 

approximate elevation of 2,000 feet msl in the Las Vegas Valley at the proposed terminal 

locations. 

1.4.2 Land Use

Most of this section of the DesertXpress Project alignment and facilities fall within the I15 transportation corridor. BLM manages lands south of Las Vegas; land in the city is in 

private ownership. Between the start of Segment 6 near Sloan Road and the Las Vegas 

passenger station, the Segment 6 alignment alternatives and facilities would traverse a 

spectrum of existing land uses. Near Sloan Road, the sparsely developed character of the 

Ivanpah Valley includes industrial uses near the freeway. North of St. Rose Parkway, the 

industrial uses give way to the outer fringes of metropolitan Las Vegas. Clusters of new 

single and multi family residential developments and several hotel/casinos are located 

near the freeway. Residences in this area are within 70 feet of the proposed alignment. 

North of Blue Diamond Road (State Route 160), land uses change; industrial uses are 

located to the west of the freeway while east of the freeway is undeveloped. After 

crossing I-215, the land uses fully reflect the intensive urban development of Las Vegas. 

Hotel/casino and commercial land uses are located on either side of the freeway. 

McCarran International Airport is located approximately a half mile to the east. 

1.4.3 Geology and Soils

A limestone formation (Mmc, Mm) mantled by younger alluvium underlies the southern 

end of the Las Vegas Wash Watershed area. The majority of the area is underlain by 

alluvial deposits, including younger Holocene wash sediments and alluvial fan deposits 

(Qa, Qal, Qs), older Holocene/Pleistocene alluvial fan deposits (Qai, Qoa) that are

F-I.5-7
moderately to well consolidated to cemented in places, and older Pliocene consolidated 

sediments (QTs) that are moderately to well consolidated to strongly cemented.

Younger Holocene alluvial wash and fan deposits (Qa) in this area may be cemented in

places by petrocalcic carbonate. Older Pleistocene alluvium (Qoa) may contain a 

petrocalcic carbonate horizon approximately 6 feet thick near the surface. Older PlioPleistocene consolidated sediments in this area have moderately to well consolidated to

strongly cemented layers of petrocalcic carbonate; surface exposures are capped in places

by a resistant petrocalcic crust.

The following table provides a description of soils associated with each geologic unit 

described above. 

Geologic Unit 

(Symbol[s]) 

Geologic Age Description - Soils

Younger alluvial 

deposits (Qa, Qal, Qs) Holocene Active wash, alluvial fan and sheet wash deposits of gravel, sand, 

and minor silt; unconsolidated to locally calcic-cemented.

Intermediate alluvial 

deposits (Qai)

HolocenePleistoceneDeposits of sand and gravel on relict, inactive alluvial fans; 

slightly to moderately consolidated.

Older alluvial deposits 

(Qoa) Pleistocene

Pebble and small cobble gravel with pebbly sand; moderately to 

well consolidated to locally cemented; caliche horizon approx. 6 

feet thick occurs at or near surface.

Consolidated sediments 

(Qts)

Pliocene to 

Pleistocene

Fine sand interbedded with silt, pebbly sand, and gravel; 

moderately to well consolidated to strongly cemented. Common 

caliche layers and resistant caliche surface crust.

Marine sedimentary and 

meta-sedimentary rocks 

(Mmc, Mm)

Mesozoic to 

Paleozoic 

(Carboniferous)

Monte Cristo limestone (Mm).

Source: Ninyo & Moore, 2007.

The general geology of the Las Vegas Valley is described in a recent USGS publication2: 

Las Vegas Valley is located in southern Nevada and lies within both the 

Great Basin and Mojave Desert sections of the Basin and Range 

physiographic province. The arid, northwest-trending valley is bounded on 

the west by several mountain ranges and drains a 1,564-square-mile 

watershed southeastward through Las Vegas Wash into Lake Mead.

Las Vegas Valley is a sediment-filled structural trough that has formed 

over many millions of years through compression, extension, and faulting 

of the original flat-lying marine sediments that form the bedrock. Some 

2 Pavelko, M. T., D. B. Wood, and R. J. Laczniak (U.S. Geological Survey, Las Vegas, Nevada). 

Las Vegas, Nevada: Gambling with water in the desert. Online at: 

http://pubs.usgs.gov/circ/circ1182/pdf/08LasVegas.pdf

F-I.5-8
bedrock blocks were down-dropped between the faults along the eastern 

and western margins of the present-day valley. Sediment eroded by wind 

and water from the surrounding bedrock highlands began filling the trough 

with gravel, sand, silt, and clay.

During some of the wetter periods in the past 1 million years or so, 

extensive playa lakes and spring-fed marshes covered the lower parts of 

the valley floor, depositing variably thick sequences of fine-grained 

sediment (citation). Coarse-grained sand and gravel tend to rim the valley, 

forming alluvial fans and terraces, especially in the northern, western, and 

southern parts. The deposits generally thicken and become finer-textured 

toward the central and eastern part of the valley, where their total thickness 

exceeds 5,000 feet (citation).

1.4.4 Biological Resources

Segment 6 would extend from the Sloan area and descend into the south end of the Las 

Vegas Valley through creosote bush scrub habitat. Once in Las Vegas, the segment 

crosses through disturbed creosote bush scrub habitat, rural developments, and urban 

areas. Segment 7 would be located in an urban environment (Las Vegas) with little to no 

habitat for sensitive species. These habitats are summarized in the following table:

Vegetation 

Community 

Type

Sensitive 

Community Associated Species Description

Creosote Bush 

Shrubland

No A group of alliances: creosote bush may be the 

only shrub, other alliances are characterized by 

shared dominance with white bursage and/or 

brittlebush; also desert holly, saltbush species, 

and many other shrubs may be present in low 

densities

Various substrates and 

settings, including: sandy 

substrates, alluvial fans, 

bajadas; may occur on 

disturbed sites; 0-1,700 

meters

Barren 

(Disturbed, 

graded)

No May have sparse growth of mostly non-native 

species, especially invasive annual grasses

Various substrates and 

settings

Rural 

development

No N/A Usually flat to gently 

sloping sites, valley floors

Urban No N/A Usually flat to gently 

sloping sites, valley floors

In the table below, sensitive species listed by US Fish and Wildlife Service and the State 

of Nevada are identified:

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Biological 

Resource

Status 

Federal/State Description

Potential for 

Occurrence in 

Segments 6 and 

7

Sensitive Plant Communities & Wetlands

Sensitive plant 

communities None present in segments No

Special-Status Plant Species

Las Vegas 

catseye

--/SS No Nevada Natural Heritage Program occurrences in 

vicinity of project study area.

No

Special-Status Wildlife Species

Desert tortoise

T/T No Nevada Natural Heritage Program occurrences in 

vicinity of project study area. Suitable habitat occurs 

in relatively undisturbed habitat outside of urban 

areas.

Yes

American 

peregrine 

falcon

--/P No Nevada Natural Heritage Program occurrences in 

vicinity of project study area. 

Yes

1.4.5 Climate

Climate in the Las Vegas Valley is described by Pavelco et al.3

 

More than 24 inches of precipitation fall annually in the Spring Mountains 

bounding the [Las Vegas] valley to the west, but less than 4 inches of rain 

fall annually on the valley floor; measurable amounts (greater than 0.01 

inch) seldom occur more than 30 days each year. Temperatures range from 

below freezing in the mountains to more than 120qF on the valley floor. 

There are typically more than 125 days of 90qF or warmer temperatures 

each year in Las Vegas Valley.

1.4.6 Hydrology

Water Resources

The DesertXpress Project proposed alignments cross named and unnamed ephemeral 

drainages that generally flow east into the Las Vegas Wash and ultimately into the 

Colorado River via Lake Mead, a reservoir of the river. Named drainages crossed by the 

alignments include Duck Creek, Tropicana Wash, and Flamingo Wash. The drainages 

are ephemeral west of the Las Vegas metropolitan area but become perennial (from urban 

“nuisance” flow) as they flow eastward and terminate at the Las Vegas Wash. Flamingo 

Wash has been channelized and routed underground through a series of culverts. There is 

no surface expression of the Wash within the project alignments. 

3 Ibid.

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Groundwater Resources

Segment 6 and Segment 7 are located in the Las Vegas Groundwater Basin (Nevada 

Basin Number 212) (DCNR, 2007). The Las Vegas Groundwater Basin is estimated to 

be 1,000,960 acres (DCNR, 2007). 

Pavelka et al.4

describe groundwater resources in the Las Vegas area: 

The accelerating demand for water to support the rapid growth of the 

municipal-industrial sector in this desert region is being met with imported 

Colorado River System supplies and local ground water. The depletion of 

once-plentiful groundwater supplies is contributing to land subsidence and 

ground failures. Since 1935, compaction of the aquifer system has caused 

nearly 6 feet of subsidence and led to the formation of numerous earth 

fissures and the reactivation of several surface faults, creating hazards and 

potentially harmful impacts to the environment. . . . 

Ground water is generally pumped from the upper 2,000 feet of 

unconsolidated sediments that constitute the aquifer system in the central 

part of the valley. The deeper aquifers, generally below 300 feet, are 

capable of transmitting significant quantities of ground water, and have 

been referred to variously as the “principal,” “artesian,” or “developedzone” aquifers (citations). In places, these principal aquifers are more than 

1,000 feet thick and consist mainly of sands and gravels beneath the 

terraces along the margins of the valley. In the central and eastern parts, 

clays and silts predominate (citation). Overlying the principal aquifers, in 

most places, is a 100-to-300 foot-thick section of extensive clay, sand, and 

gravel deposits known as the “near-surface reservoir.” The principal 

aquifers and the near-surface reservoir are separated by a variably-thick, 

laterally discontinuous aquitard, or confining unit. . . . 

Much of the ground water found in the aquifer system originates as rain or 

snow falling on the Spring Mountains to the west or on the Sheep and Las 

Vegas Ranges to the northwest. Some of the precipitation infiltrates into 

the underlying bedrock through faults and fractures, eventually moving 

into the deposits comprising the principal aquifers. The remainder of the 

precipitation runs off onto the sloping alluvial terraces and rapidly enters 

the sand and gravel deposits, where it either recharges the underlying 

principal aquifers or is evaporated or transpired into the atmosphere. 

4 Ibid.

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FEMA Floodplains 

The DEIS for the DesertXpress Project identifies several 100-year floodplains in the 

vicinity of the alignment in the I-15 transportation corridor: 

 Floodplain along an unnamed wash between West Cactus Avenue and East 

Silverado Ranch Boulevard. This wash becomes the Duck Creek drainage. 

 Tropicana Wash 100-year floodplain between I-15 and the UPRR tracks extends 

west of I-15 and south of East Tropicana Avenue, and along the railway tracks east 

of Wynn Road and north of West Oquendo Road. The flood plain is not mapped 

beyond Linwood Road south. 

 Floodplain that extends south of West Flamingo Road, west of South Las Vegas 

Boulevard, north of West Tropicana Avenue, and east of I-15. The Clark County 

Regional Flood Control District has constructed and proposed new conveyances 

within this area that have also significantly reduced the area of the 100-year 

floodplain.1.5 Disclaimer 

Huffman-Broadway Group, Inc. have conducted a thorough historic review and site 

investigation and made a good-faith effort herein to thoroughly describe and document 

the presence of potential factors that the Corps may consider in determining jurisdiction 

under their CWA jurisdiction as part of the Corps jurisdictional verification / 

determination process, however, DXE reserves the right to challenge or seek revision to 

any areas over which the Corps may assert jurisdiction.

F-I.5-12
2.0 REGULATORY FRAMEWORK

2.1 Definition of Wetlands and Other Waters of the U.S.

Section 404 of the Federal Clean Water Act authorizes the Corps to regulate activities 

that discharge dredged or fill material to wetlands and other waters of the United States. 

As described by EPA’s and the Corps’ regulations (40 CFR § 230.3(s) and 33 CFR § 

328.3(a), respectively), the term “waters of the United States" encompasses the following 

resources: 

(1) All waters which are currently used, or were used in the past, or may be 

susceptible to use in interstate or foreign commerce, including all waters 

which are subject to the ebb and flow of the tide; 

(2) All interstate waters including interstate wetlands; 

(3) All other waters such as intrastate lakes, rivers, streams (including 

intermittent streams), mudflats, sandflats, wetlands, sloughs, prairie 

potholes, wet meadows, playa lakes, or natural ponds, the use, degradation 

or destruction of which could affect interstate or foreign commerce 

including any such waters: 

(i) Which are or could be used by interstate or foreign travelers for 

recreational or other purposes; or 

(ii) From which fish or shellfish are or could be taken and sold in 

interstate or foreign commerce; or 

(iii) Which are used or could be used for industrial purpose by industries 

in interstate commerce 

(4) All impoundments of waters otherwise defined as waters of the United 

States under the definition; 

(5) Tributaries of waters identified in paragraphs (a) (1) through (4) of this 

section; 

(6) The territorial seas; 

(7) Wetlands adjacent to waters (other than waters that are themselves 

wetlands) identified in paragraphs (a) (1) through (6) of this section. 

EPA and the Corps define wetlands as: 

...those areas that are inundated or saturated by surface or ground water at 

a frequency and duration sufficient to support, and that under normal 

circumstances do support, a prevalence of vegetation typically adapted for 

life in saturated soil conditions. Wetlands generally include swamps, 

marshes, bogs, and similar areas. (EPA regulations at 40 CFR § 230.3(t); 

Corps regulations at 33 CFR § 328.3(b)). 

F-I.5-13
2.2 Limits of Jurisdiction 

The following provides the regulatory definitions and criteria followed in determining the 

geographic extent of potential EPA/Corps jurisdiction as applicable to inland waters. 

The geographic limits of relevant federal jurisdiction for non-tidal waters of the U.S. are 

defined as follows at 33 CFR § 328.4(c): 

Non-Tidal Waters of the United States: The limits of jurisdiction in non-tidal 

waters: 

(1) In the absence of adjacent wetlands, the jurisdiction extends to the 

ordinary high water mark. 

(2) When adjacent wetlands are present, the jurisdiction extends beyond the 

ordinary high water mark to the limit of the adjacent wetlands. 

(3) When the water of the United States consists only of wetlands the 

jurisdiction extends to the limit of the wetland. 

The terms “adjacent” and “ordinary high water mark,” used in the above definition, are 

defined at 33 CFR § 328.3 as follows: 

The term adjacent means bordering, contiguous, or neighboring. 

Wetlands separated from other waters of the United States by man-made 

dikes or barriers, natural river berms, beach dunes and the like are 

“adjacent wetlands.” (33 CFR § 328.3(c)) 

The term ordinary high water mark means that line on the shore 

established by the fluctuations of water and indicated by physical 

characteristics such as clear, natural line impressed on the bank, shelving, 

changes in the character of soil, destruction of terrestrial vegetation, the 

presence of litter and debris, or other appropriate means that consider the 

characteristics of the surrounding areas. (33 CFR § 328.3(e)) 

A site must meet certain water, soil, and vegetation criteria to qualify as a jurisdictional 

wetland. The Corps’ 1987 Wetlands Delineation Manual and various regional 

supplements describe these criteria and the methods used to determine whether they are 

met and the geographic extent of wetland areas identified in the field. 

2.3 Identification of Ordinary High Water Marks (OHWM)

The Corps definition of Ordinary High Water Mark (OHWM) provides the criterion by 

which the OHWM line can be identified which consists of “that line on the shore 

established by fluctuations of water and indirect physical characteristics” (33 CFR § 

328.3(e)). The Corps has developed a delineation manual for the identification of 

OHWMs within the Arid West Region, entitled A Field Guide to the Identification of the 

Ordinary High Water Mark (OHWM) in the Arid West Region of the Western United 

States, A Delineation Manual (Lichvar and McColley 2008). Tables 1a and 1b, below 

provide a summarized listing from the manual of indicators associated with areas that 

become flood or ponded, but are not dominated by wetland vegetation and the duration of 

F-I.5-14
flooding, ponding and/or near surface soil saturation (LQFKHVLVQRWVXIILFLHQWWR

cause hydric soils to form or wetland hydrology conditions to occur. 

Table 1a. Potential Geomorphic Indicators of Ordinary High Water Marks 

for the Arid West *

Potential Geomorphic OHWM Indicators 

(A) Below OHW (B) At OHW (C) Above OHW

1. In-stream dunes

2. Crested ripples

3. Flaser bedding

4. Harrow marks

5. Gravel sheets to rippled 

sands 

6. Meander bars

7. Sand tongues

8. Muddy point bars

9. Long gravel bars

10. Cobble bars behind 

obstructions 

11. Scour holes downstream 

of obstructions

12. Obstacle marks

13. Stepped-bed morphology 

in gravel

14. Narrow berms and levees

15. Streaming lineations

16. Dessication / mud cracks

17. Armored mud balls

18. Knick Points

1. Valley flat

2. Active floodplain

3. Benches: low, mid, most prominent

4. Highest surface of channel bars

5. Top of point bars

6. Break in bank slope

7. Upper limit of sand-sized particles

8. Change in particle size distribution

9. Staining of rocks

10. Exposed root hairs below intact soil layer

11. Silt deposits

12. Litter (organic debris, small twigs and leaves)

13. Drift (organic debris, larger than twigs)

1. Desert pavement

2. Rock varnish

3. Clast weathering

4. Salt splitting

5. Carbonate etching

6. Depositional topography

7. Caliche rubble

8. Soil development

9. Surface color/tone

10. Drainage development

11. Surface relief

12. Surface rounding

* Adapted from A Field Guide to the Identification of the Ordinary High Water Mark (OHWM) in the Arid West 

Region of the Western United States, A Delineation Manual (Lichvar and McColley 2008).

F-I.5-15
Table 1b. Potential Vegetation Indicators of Ordinary High Water Marks 

for the Arid West *

Potential Vegetation OHWM Indicators 

(D) Below OHW (E) At OHW (F) Above OHW

Hydroriparian 

indicators 

1. Herbaceous marsh 

species

2. Pioneer tree seedlings

3. Sparse, low 

vegetation

4. Annual herbs, 

hydromesic ruderals

5. Perennial herbs, 

hydromesic clonals

1. Annual herbs, hydromesic 

ruderals 

2. Perennial herbs, 

hydromesic clonals

3. Pioneer tree seedlings

4. Pioneer tree saplings

1. Annual herbs, xeric 

ruderals 

2. Perennial herbs, non-clonal

3. Perennial herbs, clonal and 

non-clonal co-dominant 

4. Mature pioneer trees, no 

young trees

5. Mature pioneer trees 

w/upland species

6. Late-successional species

Mesoriparian 

indicators 

6. Pioneer tree seedlings

7. Sparse, low 

vegetation

8. Pioneer tree saplings

9. Xeroriparian species

5. Sparse, low vegetation 

Annual herbs, hydromesic

6. ruderals 

7. Perennial herbs, 

hydromesic clonals

8. Pioneer tree seedlings

9. Pioneer tree saplings

10. Xeroriparian species

11. Annual herbs, xeric 

ruderals 

7. Xeroriparian species

8. Annual herbs, xeric 

ruderals 

9. Perennial herbs, non-clonal

10. Perennial herbs, clonal and 

non-clonal codominent

11. Mature pioneer trees, no 

young trees

12. Mature pioneer trees, xeric 

understory 

13. Mature pioneer trees 

w/upland species

14. Late-successional species

15. Upland species

Xeroriparian 

indicators 

10. Sparse, low 

vegetation

11. Xeroriparian species

12. Annual herbs, xeric 

ruderals 

12. Sparse, low vegetation

13. Xeroriparian species

14. Annual herbs, xeric 

ruderals 

16. Annual herbs, xeric 

ruderals 

17. Mature pioneer trees 

w/upland species

18. Upland species

* Adapted from A Field Guide to the Identification of the Ordinary High Water Mark (OHWM) in the Arid West 

Region of the Western United States, A Delineation Manual (Lichvar and McColley 2008).

2.4 Wetlands Delineation Criteria

The Corps’ 1987 Wetlands Delineation Manual identifies the key diagnostic criteria for 

determining the presence of wetlands. These include: 

1. Wetland Hydrology: Inundation or saturation to the surface during the 

growing season. 

2. Hydric Soils: Soils classified as hydric or that possess characteristics 

associated with reducing soil conditions. 

3. Predominance of Wetland Vegetation: Vegetation classified as facultative, 

facultative wet, or obligate according to its tolerance of saturated (i.e., 

anaerobic) soil conditions. 

Specific criteria used to determine the presence or absence of wetland hydrology, soil, 

and vegetation conditions are described in the sections below. 

F-I.5-16
2.4.1 Wetland Hydrology

The 1987 Corps Manual states that wetland hydrology conditions occur when a “site is 

inundated either permanently or periodically at mean water depths less than or equal to 

6.6 feet, or the soil is saturated to the surface at some time during the growing season of 

the prevalent vegetation.” Whether a site meets either of these criteria is determined by 

the presence of diagnostic indicators of wetland hydrology, which include those listed in 

Table 2.

Table 2. Wetland Hydrology Indicators

(Based on 1987 Corps Manual and Corps Guidance Documents)

Primary Indicators Secondary Indicators

Watermarks Oxidized Rhizospheres Associated with 

Living Roots

Drift Lines Water-Stained Leaves

Water-Borne Sediment Deposits FAC-Neutral Test

Drainage Patterns Within Wetlands Local Soil Survey Data

A March 8, 1992 Corps memorandum entitled Clarification and Interpretation of the 

1987 Manual provides further clarification: 

Areas which are seasonally inundated and/or saturated to the surface for a 

consecutive number of days for more than 12.5 percent of the growing 

season are wetlands, provided the soil and vegetation parameters are met. 

Areas wet between 5 percent and 12.5 percent of the growing season in 

most years may or may not be wetlands. Sites saturated to the surface for 

less than 5 percent of the growing season are non-wetlands.

Wetland hydrology indicators have also been further defined and described in the 

Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Arid West 

Region (Version 2.0) (Corps 2008). These indicators are similar to the indicators listed 

above from the 1987 Corps Manual and are presented in Table 3. 

F-I.5-17
Table 3. Wetland Hydrology Indicators for the Arid West

(Based on Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Arid West 

Region, Version 2.0)

Primary Indicators (any one indicator is 

sufficient to make a determination that 

wetland hydrology is present)

Secondary Indicators (two or more 

indicators are required to make a 

determination that wetland hydrology is 

present)

Group A – Observation of Surface Water or Saturated Soils

A1* – Surface Water X 

A2 – High Water Table X 

A3 – Saturation X 

Group B – Evidence of Recent Inundation

B1 – Water Marks X (Nonriverine) X (Riverine)

B2 – Sediment 

Deposits 

X (Nonriverine) X (Riverine)

B3 – Drift Deposits X (Nonriverine) X (Riverine)

B6 – Surface Soil 

Cracks X 

B7 – Inundation 

Visible on Aerial 

Imagery 

X 

B9 –Water-Stained 

Leaves X 

B10 – Drainage X 

B11 – Salt Crust X 

B12 – Biotic Crust X 

B13 – Aquatic 

Invertebrates X 

Group C – Evidence of Current or Recent Soil Saturation

C1 – Hydrogen Sulfide 

Odor X 

C2 – Dry-Season 

Water Table X 

C3 – Oxidized 

Rhizospheres 

along Living 

Roots 

X 

C4 – Presence of 

Reduced Iron X 

C6 – Recent Iron 

Reduction in 

Tilled Soils 

X 

C7 – Thin Muck 

Surface X 

C8 – Crayfish Burrows X 

F-I.5-18
Table 3. Wetland Hydrology Indicators for the Arid West

(Based on Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Arid West 

Region, Version 2.0)

Primary Indicators (any one indicator is 

sufficient to make a determination that 

wetland hydrology is present)

Secondary Indicators (two or more 

indicators are required to make a 

determination that wetland hydrology is 

present)

C9 – Saturation Visible 

on Aerial Imagery X 

Group D – Evidence from Other Site Conditions or Data

D3 – Shallow Aquitard X 

D5 – FAC-Neutral Test X 

* Denotes number of wetland hydrology indicator described in detail in the Regional Supplement to the 

Corps of Engineers Wetland Delineation Manual: Arid West Region (Version 2.0).

2.4.2 Hydric Soils

The 1987 Corps Manual states that the diagnostic environmental characteristics indicative

of wetland soil conditions are met when "soils are present and have been classified as 

hydric, or they possess characteristics that are associated with reducing soil conditions." 

According to the Manual, indicators of soils developed under reducing conditions may 

include: 

1. Organic soils (Histosols); 

2. Histic epipedons; 

3. Sulfidic material;

4. Aquic or peraquic moisture regime; 

5. Reducing soil conditions; 

6. Soil colors (chroma of 2 or less); 

7. Soil appearing on hydric soils list; and 

8. Iron and manganese concretions. 

A February 20, 1992, Corps memorandum entitled Regional Interpretation of the 1987 

Manual states that the most recent version of National Technical Committee for Hydric 

Soils (NTCHS) hydric soil criteria will be used (to make hydric soil determinations). 

These soil criteria specify at least 15 consecutive days of saturation or 7 days of 

inundation (flooding or ponding) during the growing season in most years.

The concept of hydric soils includes soils developed under sufficiently wet conditions to 

support the growth and regeneration of hydrophytic vegetation. Soils that are sufficiently 

wet because of artificial measures are included in the concept of hydric soils. Also, soils 

in which the hydrology has been artificially modified are hydric if the soil, in an unaltered 

state, was hydric. Some series, designated as hydric, have phases that are not hydric 

depending on water table, flooding, and ponding characteristics. As indicated above, like 

the NRCS, the Corps has typically accepted guidance for the identification of hydric soils 

developed by the National Technical Committee for Hydric Soils (NTCHS). The 

F-I.5-19
NTCHS, a working group organized by NRCS, has developed criteria for identifying and 

mapping hydric soils throughout the United States and defines a hydric soil as “a soil that 

formed under conditions of saturation, flooding or ponding long enough during the 

growing season to develop anaerobic conditions in the upper part [of the soil profile]” 

(http://soils.usda.gov/use/hydric/intro.html). The most recent (2000) version of the 

NTCHS hydric soils criteria identifies those soils that are likely to meet this definition. 

These criteria, which are accepted by most state and federal agencies, are as follows 

(http://soils.usda.gov/use/hydric/criteria.html):

1. All Histels except Folistels and Histosols except Folists, or

2. Soils in Aquic suborders, great groups, or subgroups, Albolls suborder, 

Historthels great group, Histoturbels great group, Andic, Vitrandic, and Pachic 

subgroups, or Cumulic subgroups that are: 

a. Somewhat poorly drained with a water table equal to 0.0 foot (ft) from 

the surface during the growing season, or 

b. poorly drained or very poorly drained and have either: 

(i.) water table equal to 0.0 ft during the growing season if textures 

are coarse sand, sand, or fine sand in all layers within 20 inches 

(in), or for other soils, 

(ii.) water table at less than or equal to 0.5 ft from the surface 

during the growing season if permeability is equal to or greater 

than 6.0 in/hour (h) in all layers within 20 in, or 

(iii.) water table at less than or equal to 1.0 ft from the surface 

during the growing season if permeability is less than 6.0 in/h 

in any layer within 20 in, or 

3. Soils that are frequently ponded for a long duration or a very long duration (7 

to 30 days) during the growing season, or 

4. Soils that are frequently flooded for a long duration or a very long duration (7 

to 30 days) during the growing season. 

On the basis of computer database searches for soils meeting the second criterion, NRCS 

has developed hydric soils lists for many parts of the country. Although they are useful 

for determining whether a particular soil series has the potential to support current hydric 

soil conditions

Field indicators of hydric soils are morphological properties known to be associated with 

soils that meet the definition of a hydric soil. Presence of one or more field indicators 

suggests that processes associated with hydric soil formation have taken place on the site 

being observed. The field indicators are essential for hydric soil identification because 

, caution should be used when using these lists for site-specific hydric soil 

determinations. Many soils on the lists have ranges in water table depths and other 

characteristics that allow them to be either hydric or nonhydric depending on landscape 

position and other site-specific factors (e.g., soil clay content, depth to bedrock). 

Accordingly, hydric soils lists are good ancillary tools to facilitate wetland 

determinations, but are not a substitute for onsite investigations. 

F-I.5-20
once formed, they persist in the soil during both wet and dry seasonal periods. However, 

few hydric soil indicators identify soils at a site as being currently hydric in accordance 

with the NTCHS hydric soils criteria described above. Field indicators of hydric soil 

conditions are listed in Table 4: 

Table 4. Field Indicators of Hydric Soil Conditions

(Based on 1987 Corps Manual and Corps Guidance Documents)

1. Indicators of Historical Hydric Soil 

Conditions: 2. Indicators of Current Hydric Soil Conditions:

a. Histosols

b. Histic epipedons;

c. Soil colors (e.g., gleyed or low-chroma colors, 

soils with bright mottles (Redoximorphic 

features) and/or depleted soil matrix 

d. High organic content in surface of sandy soils

e. Organic streaking in sandy soils 

f. Iron and manganese concretions 

g. Soil listed on county hydric soils list

a. Aquic or peraquic moisture regime (inundation 

and/or soil saturation for FRQWLQXRXVGD\V

b. Reducing soil conditions (inundation and/or soil 

saturation for FRQWLQXRXVGD\V

c. Sulfidic material (rotten egg smell)

The presence of one or more of the field indicators in “1 a, b, c, and/or d” above suggests 

that historical processes associated with hydric soil development have taken place at a 

given site. These indicators are useful in determining if soils at a site were historically 

formed under hydric soil conditions because the indicators persist in soils during both wet 

and dry periods and may remain for decades and even centuries after changes in site 

conditions occur that inhibit subsequent wetland development, such as the elimination of 

wetland hydrology (NRCS 1995). However, only the presence of field indicators “2 a, b, 

and/or c” confirms that hydric soils occur at a site during the period of observation. 

Hydric soil indicators have also been further defined and described in the Regional 

Supplement to the Corps of Engineers Wetland Delineation Manual: Arid West Region 

(Version 2.0) (Corps 2008). These indicators are similar to those listed above from the 

1987 Corps Manual and are presented below in Table 5. 

F-I.5-21
Table 5. Hydric Soil Indicators for the Arid West

(Based on Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Arid West Region,

Version 2.0)

Hydric Soil Indicators Hydric Soil Indicators 

All Soils Sandy Soils Loamy & Clayey Soils for Problem Soils**

A1* – Histosol S1 – Sandy Mucky 

Mineral

F1 – Loamy Mucky 

Mineral A9 – 1 cm Muck

A2 – Histic Epipedon S4 – Sandy Gleyed 

Matrix

F2 – Loamy Gleyed 

Matrix A10 – 2 cm Muck

A3 – Black Histic S5 – Sandy Redox F3 – Depleted Matrix F18 – Reduced Vertic

A4 – Hydrogen Sulfide S6 – Stripped Matrix F6 – Redox Dark Surface TF2 – Red Parent 

Material

A5 – Stratified Layers -- F7 – Depleted Dark 

Surface

Other (See Section 5 of 

the Regional Supplement, 

Version 2.0)--

A9 – 1 cm Muck -- F8 – Redox Depressions --

A11 – Depleted Below 

Dark Surface

-- F9 – Vernal Pools --

A12 – Thick Dark 

Surface

-- -- --

* Denotes number of hydric soil indicator described in detail in Regional Supplement to the Corps of 

Engineers Wetland Delineation Manual: Arid West Region (Version 2.0). 

** Indicators of hydrophytic vegetation and wetland hydrology must be present.

It should also be noted for problematic areas that the 2008 Corps Regional Supplement 

specifies 14 days continuous ponding as an acceptable indicator of problematic hydric 

soils (USACE 2008, p. 101). 

2.4.3 Prevalence of Wetland Vegetation

Species Classifications

Species classifications (e.g., tolerance of anaerobic soil conditions) are determined by 

consulting the National List of Plant Species that Occur in Wetlands (Reed 1988) and the 

relevant regional lists, which are published by FWS’ National Wetlands Inventory (NWI). 

Regional Interagency Review Panels develop the lists by determining species’ estimated 

probability of occurrence in wetlands vs. non-wetlands. Classifications are made by 

unanimous agreement of the Panel. If the Panel is unable to reach a unanimous decision 

on the status of a species, “no agreement” (NA) is recorded. If insufficient information 

exists to determine the status of a species, “no indicator” (NI) is recorded. Species that 

are not included in the NWI list are assigned a “not listed” (NL) designation in this report. 

The resulting NWI lists include plants that grow in a range of soil conditions from 

permanently wet to dry. Species are divided into the following “indicator categories”:

F-I.5-22
1. “Obligate wetland” (OBL) species, which, under natural conditions, occur 

almost always in wetlands (estimated probability >99 percent);

2. “Facultative wetland” (FACW) species, which usually occur in wetlands 

(estimated probability 67 – 99 percent), but are occasionally found in nonwetlands;

3. “Facultative” (FAC) species, which are equally likely to occur in wetlands 

or non-wetlands (estimated probability 34 – 66 percent); 

4. “Facultative upland” (FACU) species, which sometimes occur in wetlands 

(estimated probability 1 – 33 percent), but more often occur in nonwetlands; and

5. “Obligate upland” (UPL) species, which occur in wetlands in other 

regions, but, under natural conditions, occur almost always in non-wetlands 

in the region specified (estimated probability >99 percent).

Species that have an indicator status of OBL, FACW, and FAC are typically considered 

to be adapted for life in anaerobic soil conditions (Corps 1987) and are used as evidence 

of hydrophytic vegetation when they dominate plant community composition or cover. 

Despite widespread use of the lists for wetland delineations, it is important to note that 

wetland indicator species assignments are not based on the results of a statistical analysis 

of species occurrence. The indicator assignments are approximations of wetland affinity 

based on a synthesis of submitted review comments, published botanical literature, and 

the field experience of the members of the Interagency Review Panel. For this reason and 

because many plants have properties that enable them to occur in a range of microhabitats 

(i.e., wetlands and non-wetlands), the presence of wetland indicator species is not 

unequivocal evidence of the presence of wetland hydrology and hydric soils. A positive 

indicator or indicators of wetlands should be emphasized, such as an assemblage of plants 

that can only be considered “hydrophytes” when they are growing in water or partly 

drained hydric soils (not effectively drained hydric soils) (Corps 1987). From the FWS 

perspective, all species on the NWI plant lists are hydrophytes at one time or another and 

the wetland indicator status (OBL, FACW, FAC, or FACU) reflects the likelihood that a 

given individual of a species is a hydrophyte or a certain population of these plants is 

hydrophytic. While OBL and FACW species are the most reliable plant indicators of 

wetlands, FAC and FACU species also contain populations of hydrophytes (Tiner 2006). 

For the reasons stated above, the 1987 Corps Manual does not solely rely on the presence 

of hydrophytic vegetation to make wetland determinations.

Hydrophytic Vegetation Definitions 

The Corps’ 1987 Manual states that the wetland vegetation conditions are met when the 

prevalent vegetation (i.e., more than 50 percent of vegetation cover or tree basal area) 

consists of macrophytes that are typically adapted to sites having wetland hydrologic and 

soil conditions (e.g., periodic or continuous inundation or soil saturation). Hydrophytic 

vegetation is defined as “plant life growing in water or on a substrate that is at least 

periodically deficient in oxygen as a result of excessive water content” (Cowardin et al.

F-I.5-23
1979). Hydrophytic vegetative species, due to morphological, physiological, and/or 

reproductive adaptation(s), have the ability to grow, effectively compete, reproduce, 

and/or persist in anaerobic soil conditions. Positive indicators of the presence of 

hydrophytic vegetation include: 

1. More than 50 percent of the dominant species are rated as Obligate ("OBL"), 

Facultative Wet ("FACW"), or Facultative ("FAC") on lists of plant species 

that occur in wetlands (see Reed 1988 for California); 

2. Visual observations of plant species growing in sites of prolonged inundation 

or soil saturation; and 

3. Reports in the technical literature indicating the prevalent vegetation is 

commonly found in saturated soils. 

Hydrophytic vegetation indicators have been further defined and described in the 

Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Arid West 

Region (Version 2.0) (Corps 2008). These indicators include:

1. Dominance Test

2.

. More than 50 percent of the dominant plant species across 

all strata are rated OBL, FACW, or FAC. 

Prevalence Index

3.

. The prevalence index is 3.0 or less with indicators of 

hydric soils and wetland hydrology being present. 

Morphological Adaptations. The plant community passes either the 

dominance test or the prevalence index after reconsideration of the indicator 

status of certain plant species that exhibit morphological adaptations for life in 

wetlands. 

F-I.5-24
3.0 DELINEATION METHOD

This study was conducted in accordance with Code of Federal Regulations (CFR) 

definitions of jurisdictional waters, the Corps’ 1987 Wetlands Delineation Manual, the 

Corps’ 2008 Regional Supplement to the Corps of Engineers Wetland Delineation 

Manual: Arid West Region (Version 2.0), A Field Guide to the Identification of the

Ordinary High Water Mark (OHWM) in the Arid West Region of the Western United 

States, A Delineation Manual, and supporting guidance documents. The following 

provides an overview of the objective of the delineation approach, how the Study Area is 

defined, and the methods used to identify and map (delineate) areas potentially subject to 

Corps jurisdiction under Section 404 of the CWA. 

3.1 Objective and Establishment of Study Area Boundary

The objective of this investigation is to identify and map areas potentially meeting the 

Clean Water Act definition of wetlands and Other Waters of the United States within the 

potential impact footprint of the DesertXpress Project. This impact footprint, which is 

encompassed within the Study Area, includes the proposed alignment and any alternative 

alignment and support facilities such as passenger stations and operations and 

maintenance facilities (e.g., maintenance yard, power substations, and transmission lines). 

 Temporary construction areas for equipment and materials laydown, new access roads, 

and borrow areas are also included within the Study Area. The boundary of the Study 

Area also represents a slightly larger area (increased alignment and facility ROW width 

by an average of 200 feet) to accommodate potential minor changes in the impact 

footprint. 

3.2 Study Area Reconnaissance

Prior to initiating detailed field survey work, existing land forms within the Study Area 

that may potentially contain wetlands or other waters of the United States were identified 

by conducting vehicle and pedestrian on-site reconnaissance inspections during the month 

of April 2010 in conjunction with review of the following information: 

x Aerial photography and satellite imagery of the area;

x USGS topographic mapping; 

x NRCS soils mapping; 

x Engineer scale topographic mapping of segment alternatives

x USGS National Hydrology Dataset; and

x Preliminary level vegetation mapping and wetland / OHWM data collection 

efforts conducted during February and March 2008 and September and October 

2009 as part of an on-going Federal EIS process by the FRA’s EIS contractor. 

The above efforts led to the development, in coordination with Corps regulatory staff, and 

use of the project-specific methods described below. 

3.3 Wetlands Identification and Delineation

Field surveys designed to identify the presence or absence of field indicators of wetland 

F-I.5-25
vegetation, soils and hydrology conditions were conducted within low-lying landscape 

features where wetlands could potentially occur. These field surveys were conducted 

during the months of April, May, and June 2010. 

3.3.1 Dominance of Wetland Vegetation

Presence or absence of a dominance of wetland vegetation / hydrophytes within the Study 

Area was evaluated using the methodology described in Sections 2.2 and 2.4.3. Indicator 

status of plants was confirmed by referring to the National List of Plant Species that 

Occur in Wetlands: 1988 National Summary (Reed). Plant cover data were collected for 

individual species associated within and immediately adjacent to the landscape features 

identified during the site reconnaissance survey as having the potential to meet the Corps’ 

technical criteria for wetlands. Plant cover was visually estimated within 3-foot diameter 

plots at each soil sample location and was recorded on a Corps Wetland Determination 

Data Form – Arid West Region. Copies of completed data forms are provided in Exhibit 

B2. Subsequently, field data were analyzed to assess whether 50 percent or greater of the 

dominant species within the area sampled are hydrophytes. Sites that are depressional 

landforms that do not have a dominance of wetland vegetation forming at least 5 percent 

cover were not considered to be dominated by hydrophytes and were classified as a 

potential “other water of the United States” following the methodology described in 

Section 3.4, below, except if conditions for problematic vegetation were met as described 

in the Corps’ 2008 Regional Supplement to the Corps of Engineers Wetland Delineation 

Manual: Arid West Region (Version 2.0).

3.3.2 Presence of Hydric Soil Indicators

The presence or absence of hydric soil field indicators was evaluated following the 

methodology described in Section 2.3.2 using the Regional Supplement to the Corps of 

Engineers Wetland Delineation Manual: Arid West Region (Corps 2008). At each 

potential wetland sampling location within the Study Area, hand-dug soil pits were 

excavated to a minimum of 20 inches or until a limiting layer or standing water is 

reached. The presence or absence of hydric soil indicators found at each soil pit location 

was recorded on a Corps Wetland Determination Data Form – Arid West Region. Copies 

of completed data forms are provided in Exhibit B2. For sampling locations where the

possibility of problematic hydric soils is found, procedures for the identification of 

problematic hydric soils as defined by the above described publication were followed. 

3.3.3 Presence of Wetland Hydrology Indicators 

The presence or absence of wetland hydrology field indicators were assessed following 

the methodology described in Section 2.3.1 using the Regional Supplement to the Corps 

of Engineers Wetland Delineation Manual: Arid West Region (Version 2.0) (Corps 

2008). The presence or absence of wetland hydrology indicators at each soil pit location 

was recorded on a Corps Wetland Determination Data Form – Arid West Region. Copies 

of completed data forms are provided in Exhibit B2. For sampling locations where the 

possibility of problematic hydrology indicators was found, procedures for the 

identification of problematic hydrology indicators, as defined by the above-described 

publication, were followed. 

F-I.5-26
3.4 Identification and Delineation of Other Waters

Field surveys designed to identify the presence or absence of field indicators of an 

ordinary high water mark (OHWM) were conducted within low-lying landscape features 

where other waters of the United States could potentially occur. These field surveys were 

conducted during the months of April, May, and June 2010 after the detailed 

methodology was reviewed and approved by Corps staff during May 2010. 

HBG identified drainages within each watershed that potentially met the Corps technical 

criteria for Other Waters of the United States (presence of field indicators of active 

surface water flow and associated Ordinary High Water Mark [OHWM]) using the 

following approach based on A Field Guide to the Identification of the Ordinary High 

Water Mark (OHWM) in the Arid West Region of the Western United States, A

Delineation Manual.

Initial efforts involved identification of all drainages within the Study Area having the 

potential for active surface flow. This was accomplished through field reconnaissance 

and imagery interpretation. Detailed sampling was then conducted to identify and 

delineated active drainages with an OHWM. This was accomplished by randomly 

sampling the identified drainages in a stratified manner by geographically dividing the 

Study Area into HUC 12 watershed units. 

Field sampling within each HUC 12 watershed consisted of gathering OHWM data, 

including the measured width of the OHWM, for 3 to 5 main drainages (> 3 feet), if 

present, selected at random; and 6 to 10 (depending on watershed size) random samples 

of minor drainages (feet), if present. Each of the HCC 12 watersheds located within 

the Study Area was divided into approximate thirds. Then a minimum of one major 

drainage and two minor drainages, if present, was sampled within each third of a 

watershed. Where the length of the watershed along the project alignment alternatives 

was less than 5 miles, the watershed was divided into approximate halves instead. If the 

minor drainages (IHHWRFFXUring within each one-third watershed varied in OHWM 

width by more than 33 percent, sampling was increased in that third of the watershed. 

Drainage data for each of the watershed drainages sampled were collected on a 

standardized field data sheet (Exhibit B2). Exhibit A, Figures 5-12 provide examples of 

the types of field indicators observed within various drainages along the DesertXpress 

Project alternative alignments. Each field sampling point was memorialized using a 

handheld GPS unit with submeter accuracy. Where stormwater flows originated upslope 

of the side of I-15 opposite the alignment, those drainages were hydrologically cut off by 

the freeway during construction and channeled into detention basins and / or manmade 

drainages on that side of I-15. As a consequence, drainages on the proposed alignment 

side of I-15 were hydrologically cut off from their sources and no longer technically meet 

the Corps OHWM criterion. This condition was noted on the field data sheets. Detailed 

OHWM indicator data for these historical drainage features were not collected. 

F-I.5-27
All drainage data (field and photointerpreted drainage data) are summarized by HUC 12 

watershed on the required Los Angeles District Excel JD Summary Data Sheet (see 

Exhibit B1). Widths for active drainages identified through photointerpretation are based 

on an average width calculated from field data. The length of each drainage is based on 

photointerpretation. Standardized field data sheets are provided in Exhibit B2. 

Representative photographs of various drainage features are presented in Exhibit A on 

Figures 13 – 23. The field data collected from each watershed were used to aid in the 

imagery interpretation process described in Section 3.5, below. 

3.5 Mapping

Wetland indicator data sample locations and the locations of areas identified during field 

surveys that are potentially Other Waters of the United States due to the presence of an 

OHWM were mapped using a hand-held Trimble XT global positioning system (GPS) 

unit with sub-meter accuracy. This GPS data was incorporated into a Geographic 

Information System (GIS) and geo-referenced in overlay fashion onto digital 

orthorectified satellite imagery and/or high resolution aerial photograph depending on 

availability. Overlays were used to assist in analysis, identification, and digitization of 

the location and geographic extent of areas that could potentially qualify as waters of the 

United States. The imagery interpretation process involved the combined use of available 

imagery, field data, engineer level topographic mapping, field verification of mapped 

features and best professional judgment to map the geographic extent of areas potentially 

subject to Corps CWA jurisdiction. Exhibit C comprises detailed 1”=200’ scale mapping 

of the Study Area with field sampling points and delineated active linear drainage 

features. Labeling indicating their average OHWM width was overlain on orthorectified 

digital imagery. The maps are provided in digital PDF format due to the extensive 

numbers of maps required to show such detail. 

F-I.5-28
4.0 TECHNICAL FINDINGS

The following sections describe the landscape features and field indicators found within 

the Study Area that provide a technical basis for (a) determining the presence or absence 

of a potential water of the United States; and (b) defining the geographic extent of any 

potential water of the United States identified. Two types of landscape features were 

found that potentially contain waters of the United States. These include: 

1. Natural drainages

2. Manmade drainages

4.1 Field Indicators of Hydric Soils

Based on field observations within the Study Area soil indicators were not found that 

meet the wetland hydrology criteria defined by current Corps’ regulatory guidance, 

including the 2008 Regional Supplement to the Corps of Engineers Wetland Delineation 

Manual: Arid West Region (Version 2.0) except for a few locations within manmade 

ephemeral drainage channels that periodically receive irrigation runoff from adjacent 

landscaped areas. When periodic maintenance of broken irrigation sprinklers and piping 

occurs, the localized area no longer floods, ponds and/or saturates for long to very long 

periods of time. Onsite observations of surface conditions, including road and channel 

bank cuts and interpretation of aerial photography revealed three primary soil types, 

disturbed urban land, desert pavement, and more active wash sediments. Onsite 

examination revealed that soils or substrates within both natural drainages and manmade 

drainages consist of alluvial materials primarily made up of sorted sands and gravel, and 

are well drained, ranging from moderately well drained to excessively well drained.

4.2 Field Indicators of Wetland Hydrology Conditions

Based on field observations within the Study Area wetland hydrology indicators were not

found that meet the wetlands hydrology criteria defined by current Corps’ regulatory 

guidance, including the 2008 Regional Supplement to the Corps of Engineers Wetland 

Delineation Manual: Arid West Region (Version 2.0). Onsite observations revealed 

evidence of flooding within the low-lying natural and manmade drainages. These 

observations also showed that there was no evidence of ponding and soil saturation for 

long to very long periods of time. The lack of ponding and soil saturation conditions 

meeting the wetland hydrology criteria is a direct result of the moderately well drained to 

excessively well drained alluvial soils. This is also the case for portions of manmade 

drainages receiving irrigation runoff water (nuisance flow) from adjacent landscaped 

areas. When periodic maintenance of broken irrigation sprinklers and piping occurs, the 

localized area no longer floods, ponds, and/or saturates for long to very long periods of 

time. 

Although wetland hydrology conditions were not found within the Study Area, the field 

indicators of active surface water flow or flooding found within natural and manmade

drainages were sufficient enough to form Ordinary High Water Marks (OHWM). As 

indicated in Section 2.0, an OHWM provides a technical basis for (a) determining the 

F-I.5-29
presence a potential water of the United States; and (b) defining the geographic extent of 

potential water of the United States. 

The natural and manmade drainages within the Study Area found with an OHWM 

exhibited the following characteristics which are discussed in detail in the following 

subsections: 

1. identifiable field indicators of surface flow 

2. identifiable landscape features that supports surface flow

3. identifiable landscape features with a recognizable OHWM 

Exhibit A, Figures 5-12 provides typical examples of field indicators of active surface 

water flow and OHWMs found within ephemeral drainages occurring within the 

DesertXpress Project Study Area. Exhibit A, Figures 13-23 provide photographs of 

various types of drainages observed within the HUC 8 Las Vegas Wash watershed. 

4.2.1 Field Indicators of Surface Flow

Review of topographic mapping (USGS and Engineer scale) and imagery of the Study 

Area provided visual indication of the presence of curvilinear depressional land surface 

features where focused surface water flow could potentially be directed. Linear drainage 

features associated with road drainage and flood control were also found. Field 

investigations confirmed the presence of surface flow within a number of these channels 

or drainages while others lacked evidence / field indicators of active ephemeral surface 

water flow. No drainages were found to contain evidence of perennial or intermittent 

surface water flow, and no evidence of subsurface flow was found in the form of spring 

discharges, artesian flows or evidence of a high groundwater table. An exception to this 

was occasional points where nuisance flow discharges from landscaped areas adjacent to 

the Study Area were evident, but the runoff water in these areas appeared (on the basis of 

a lack of hydric soil indicators) to have flowed through the porous soils, neither ponding 

and/or causing saturated soil conditions to occur for long to very long durations. 

Channels further toward the Las Vegas Wash appeared to have perennial to intermittent 

flows. 

Observation of active natural and manmade ephemeral drainages revealed evidence of 

surface water / hydrologic connectivity with other active drainages within and outside the 

Study Area. These ephemeral drainages are locally referred to as “desert dry washes.” 

The manmade drainages served to redirect surface flow from altered natural drainages. 

Indicators of drainages having active surface water flow paths included (1) water marks 

defined by linear deposits of fine-grained sediment, minerals and/or plant debris; (2) bank 

scour, erosion and/or shelving; (3) deposits of sorted alluvial materials; and (4) flowdeposited woody and soft tissue plant debris (Exhibit B2). 

Flow-deposited woody and soft tissue plant debris were typically absent in drainages that 

did not have active surface flow. If woody debris was present, the pieces observed were 

relatively thick (i.e., greater that 1⁄4 inch) weathered limb or root material or milled posts 

F-I.5-30
or lumber. The wood pieces found were randomly placed and were not part of a 

collective flow line of deposited woody and/or soft tissue plant debris, which would be 

indicative of an active channel. The historical drainages were found to possess one or 

more of the same type of indicators found in active drainages, but the indicators found 

were considerably weathered. Surface flow indicators such as bank scour, erosion and 

shelving areas had rounded edges in contrast to those found in active drainages having 

angular edges. Water marks defined by linear deposits of fine grained sediment and 

minerals, and sorted alluvial materials such as gravels, cobbles and boulders were etched 

or varnished from weathering. The historical drainages were found to consist of the 

historical remains of channel drainages that were abandoned due to upslope changes in 

drainage due to either channel down-cutting or the channel becoming abandoned as the 

surface drainage became redirected or changed course due to deposition of alluvial 

material damming the channel flow path. The historical drainages were found to lack 

indicators of active flow.

Surface water flow patterns were also found within various portions of the landscape that 

were relatively flat. These surface flow areas were defined by flow-deposited finegrained sediment or soft tissue plant debris. The visible surface flow pattern at these 

locations would continue for several feet then disappear either on a relatively flat soil 

surface or localized depression.

Based on the above technical findings and as documented in Exhibits B and C, drainages 

were found with indicators of active surface water flows within the Study Area.

4.2.2 Landscape Features that Support Surface Flow

Detailed field surveys identified land surface features that have the potential to convey 

surface flows. These features included a bed or channel and abutting banks. These 

physical features were found associated with both active flow areas and historical 

drainages. These drainage types can be summarized as follows:

1. Active drainage channel and abutting banks containing evidence of recent surface 

flows as indicated by the presence of unweathered sediment material (sand, 

gravel, cobbles, etc.) with unweathered surfaces, and the presence of flow 

deposited woody debris and/or soft tissue plant debris. 

2. Active drainage channel and abutting banks containing evidence of historical 

surface flows as indicated by the presence of unweathered sediment material 

(sand, gravel, cobbles, etc.) with unweathered surfaces, but lacked the presence of 

flow deposited woody debris and/or soft tissue plant debris.

3. Historical drainage channels and abutting banks having no evidence of recent 

surface flow as indicated by weathered sedimentary gravel, cobbles, boulders, 

erosional or depositional deposits, and the lack of flow deposited woody debris 

and/ or soft tissue plant debris. 

The frequency interval of flow events within drainages with observable plant debris (1 

above) and unweathered sediment material is estimated to be within the 1 to 15 year 

F-I.5-31
range. Strojan, et. al. (1987) found that surface litter decomposition rates for creosote 

bush and burro bush in the Mojave Desert were 42.5% and 58.4%, respectively over a 54 

week period of study. Kemp, et. al. (2003) reported a similar one year decomposition rate 

for creosote bush and a 74% loss within a 41 month period. This lends support to 

qualitative observations made by one of the preparers of this report, Dr. Terry Huffman, 

who has observed over 20 + years of delineating wetlands within arid environments that 

soft plant tissue (i.e., pieces of plant leaves and thin bark) will decompose in arid 

drainage environments within a 2 to 3 year period. In addition, field observations over 

these years indicated that small woody stems (<1/4 inch) decompose over many more 

years, perhaps 10 + years. For older drainages where the surfaces of the sediment 

material (e.g., sand, gravel, cobbles, etc.) is no longer smoothed by the interaction of 

surface water flow and transport, but weathered, and lacks flow deposited woody and thin 

tissue plant debris, the frequency interval likely ranges to well over a decade in shallower 

channels to prehistoric times for deeply incised channels (i.e. > 6 feet in desert pavement 

areas).

The land surface of the Study Area is characterized by the presence of active and inactive 

alluvial fan systems. Ephemeral drainage channels are found on both types of these 

alluvial fan types. The majority of the ephemeral channels supporting active surface 

water flow were narrow, with an average width of less than 3 feet. Active alluvial fans 

were characterized by sandy soils, a uniform vegetation type, and evidence by surface 

flow patterns indicative of surface water sheetflow. Narrow channels within these areas 

were both weakly expressed and discontinuous. This discontinuity indicated that new 

channels could be formed with each major flood event resulting in the current channels 

being bypassed and blocked off. Channels >3 feet wide were also found. These channels 

were considerably deeper that the narrow channels found and were less common when 

considering the landscape as a whole in relationship to the Study Area. Evidence was 

found within both of these channel types where previously bypassed cutoff channels 

where becoming filled with sediment. The specific conditions varied within the Study 

Area.

Based on the above technical findings, drainages with active surface flow were found 

within the Study Area with physical features that allow for the conveyance of surface 

flows. 

4.2.3 Landscape Features with a Recognizable OHWM

The desert dry washes with active flow were found to have identifiable features which 

represented the geographic reach of lateral surface water. These features included 

channels or beds with evidence of active flow and abutting banks which demarcated the 

lateral reach or extent of flow. Field indicators of the extent of active flow along the 

banks included water marks defined by linear deposits of fine grained sediment and/or 

minerals, bank scour, erosion, and/or shelving, and flow deposited woody and soft tissue 

plant debris (Exhibit B2). 

Based on the above technical findings, the active drainages, described in the above 

F-I.5-32
subsections, have recognizable landscape features from which the lateral extent of surface 

water flow can be geographically delineated. Field indicators of this surface water flow 

were used to identify the OHWM. Exhibit C shows the location of these active 

ephemeral drainages.

4.3 Field Indicators of Wetland Vegetation

Based on field observations within the Study Area, a dominance of wetland plant species 

was found within portions of manmade ephemeral drainages adjacent to or downdrainage of irrigated landscaped areas. These patches of wetland vegetation were 

typically found along the edge of the drainages in association with what appeared to be 

where periodic releases of runoff water from landscape irrigation was occurring. The 

wetland vegetation typically dominated < 5% of the total area of the ephemeral drainages. 

 Wetland plant species found within these types of areas included Arrow Weed (Pluchea 

sericea; FACW), Bermuda Grass (Cynodon dactylon; FAC), Mule Fat (Baccharis 

salicifolia; FACW), Turpentine Broom (Tamarix ramosissima; NL), Narrow Leaf Cattail 

(Typha angustifolia; OBL) and California Fan Palm (Washingtonia filifera; NO).

Based on this result, the criteria defined by current Corps’ regulatory guidance, including 

the 2008 Regional Supplement to the Corps of Engineers Wetland Delineation Manual: 

Arid West Region (Version 2.0), for wetland vegetation were met in these artificially 

irrigated portions of the manmade ephemeral drainages. However, the vegetation did not 

dominate entire drainages and, therefore the drainages were not determined to be 

dominated by wetland vegetation, but rather delineated as ephemeral drainages as 

described above through the measurement of an identifiable OHWM, if found to be 

present. 

A dominance of wetland plant species or hydrophytes was not found within natural 

drainages or the majority of manmade drainages encountered within the Study Area 

where active ephemeral drainages were found. Based on this result, the criteria defined 

by current Corps’ regulatory guidance, including the 2008 Regional Supplement to the 

Corps of Engineers Wetland Delineation Manual: Arid West Region (Version 2.0) for 

wetland vegetation was not met for these areas. 

F-I.5-33
5.0 AREAS POTENTIALLY SUBJECT TO JURISDICTION 

This section presents the findings of this delineation with respect to the identification and 

geographic extent of areas found that could potentially be regulated by the Corps and the 

EPA as wetlands or other waters of the United States under Section 404 of the Clean 

Water Act.

5.1 Wetlands 

No areas meeting the Corps technical criteria for wetlands were identified within the 

Study Area. These findings are based on the absence of hydric soil, wetland hydrology, 

and / or wetland vegetation indicators as required by the Corps’ 1987 Manual, the Arid 

West Regional Supplement, guidance documents, and regulations. 

5.2 Other Waters of the U.S.

Ephemeral drainages or desert dry washes were found within the Study Area that meet the 

technical criteria to potentially be subject to CWA Section 404 jurisdiction as Other 

Waters of the United States (Exhibit C). This finding is based on the presence of an 

OHWM as required by Corps regulations. Length and width measurements of the 

ephemeral drainages found to contain an observable OHWM are provided by Exhibit B2. 

F-I.5-34
6.0 REFERENCES

Eberhart/United Consultants. 2007. Phase 1 Geologic Reconnaissance Report: 

Proposed Desert Sunlight Solar Energy Project, Desert Center Area, Riverside County, 

California. W.O. 81-02120-0031. June 21. 

Environmental Laboratory. 1987. Corps of Engineers Wetlands Delineation Manual.

Technical Report Y-87-l, US Army Engineer Waterways Experiment Station, Vicksburg, 

Miss.

Field, J., & Pearthree, P. 1997. "Geomorphologic Flood-Hazard Assessment of Alluvial 

Fans and Piedmonts." Journal of Geoscience Education, Vol. 45, pp. 27 – 37. 

Hickman, J. (ed.). 1993. The Jepson Manual: Higher Plants of California. University of 

California Press, Berkeley, California.

Lichvar, R.W., D.C. Finnegan, and M.P. Ericsson. 2004. Using Hydrogeomorphic 

Surfaces for Delineating Floodplains: Black Water Creek Test Reach Within the Upper 

Puerco Watershed, Navajo Nation. ERDC/CRREL Technical Note 04-7. Hanover, NH: 

U.S. Army Engineer Research and Development Center, Cold Regions Research and 

Engineering Laboratory. November. 

Lichvar. R.W., and S.M. McColley. 2008. A Field Guide to the Identification of the 

Ordinary High Water Mark (OHWM) in the Arid West Region of the Western United 

States, A Delineation Manual. ERDC/CRREL TR-08-12. Hanover, NH: U.S. Army 

Engineer Research and Development Center, Cold Regions Research and Engineering 

Laboratory. August. 

Munz, P.A. 1974. A Flora of Southern California. University of California Press, 

Berkeley, California.

Reed, P.B., Jr. 1988. National List of Plant Species that Occur in Wetlands: National 

Summary. U.S. Fish and Wildlife Service Biological Report 88(24). 244 pp. 

Santos, P.F., N. Z. Elkins, Y. Steinberger and W. G. Whitford. “A Comparison of 

Surface and Buried Larrea Tridentata Leaf Litter Decomposition in North American Hot 

Deserts.” Ecology, Vol. 65, No. 1 (Feb., 1984), pp. 278-284. 

Sawyer, J.O., and T. Keeler-Wolf. 1995. A Manual of California Vegetation.

Sacramento, CA: California Native Plant Society. 471 p. 

Simley, J.D. and J.W.Carswell Jr. 2009. National Hydrography Dataset (NHD). The 

National Map - Hydrography: U.S. Geological Survey Fact Sheet 2009-3054, 4 p. 

F-I.5-35
Strojan, C.L, D. C. Randall and F. B. Turner. 1987. “Relationship of Leaf Litter 

Decomposition Rates to Rainfall in the Mojave Desert.” Ecology, Vol. 68, No. 3 (Jun., 

1987), pp. 741-744. 

U.S. Army Corps of Engineers. 2008. Regional Supplement to the Corps of Engineers 

Wetland Delineation Manual: Arid West Region (Version 2.0), ed. J. S. Wakeley, R. W. 

Lichvar, and C. V. Noble. ERDC/EL TR-08-28. Vicksburg, MS: U.S. Army Engineer 

Research and Development Center.

U.S. Army Corps of Engineers. 2009. Vegetation and Channel Morphology Responses 

to Ordinary High Water Discharge Events in Arid West Stream Channels, ed. R. 

Lichvar, D. Cate, C. Photos, L. Dixon, B. Allen, and J. Byersdorfer. ERDC/CRREL TR09-5. Hanover, NH: U.S. Army Engineer Research and Development Center, Cold 

Regions Research and Engineering Laboratory. May. 

U.S. Department of Agriculture, Natural Resources Conservation Service. 1986. Urban 

Hydrology for Small Watersheds. Technical Release 55 (TR-55). June. 

US Department of Agriculture, National Resources Conservation Service. 2009. Web 

Soil Survey: http://websoilsurvey.nrcs.usda.gov 

F-I.5-36
Exhibit A

Figures

Figure 1 DesertXpress Project Alignment Alternatives

Figure 2 Location of Alignment Alternatives Within HUC-8 Watershed

Figure 3 Location of Study Area

Figure 4 Location of Study Area Within HUC-8 / HUC-12 Watersheds

Figures 5-12 Typical Examples of Field Indicators of Active Surface Water Flow and 

Ordinary High Water Marks Found Within Ephemeral Drainages 

Occurring Within the DesertXpress Project Study Area.

Figures 13-23 Examples of Drainages Found Within HUC-8 Watershed

F-I.5-37
Figure 1. DesertXpress Project Alignment Alternatives

RecentSEGMENT 6B Alignment

Previous SEGMENT 7A and 7B

PreviousSEGMENTOld Victorville Station

VICTORVILLE

BARSTOW

LAS VEGAS

NEVADA CALIFORNIA

Yermo

Baker

Current PreferredVictorville Station

Halloran Summit

Primm

Current PreferredLas Vegas Station

Jean

Mountain Pass

SEGMENT

2 ALT C

SEGMENT 6 ALT B

SEGMENT 4 ALT C

SEGMENT 5 ALT B

SEGMENT 1 ALT B

SEGMENT 3 ALT B

Previous SEGMENT 7C

Previous SEGMENT Old 1

Previous

SEGMENT

Old 2

Previous SEGMENT 4A

Previous SEGMENT

6C Central A and B

LegendCurrent Preferred SegmentsSegName

SEGMENT 1 ALT BSEGMENT 2 ALT CSEGMENT 3 ALT BSEGMENT 4 ALT CSEGMENT 5 ALT BSEGMENT 6 ALT B

Previous SegmentsLabel

Recent 6B AlignmentPrevious SEGMENT 4APrevious SEGMENT 6C Central A and BPrevious SEGMENT 7APrevious SEGMENT 7BPrevious SEGMENT 7CPrevious SEGMENT Old 1Previous SEGMENT Old 2

Current PreferrLas Vegas Stat

SEGMENT 6 ALT B

Previous SEGMENT 7C

Previous SEGMENT 7A and 7B

Recent SEGMENT 6BAlignment

Previous

SEGMENT 6C

Central A and B

0 5 10 Miles

Previous SEGMENT Old Victorville Station

F-I.5-38
Recent

SEGMENT 6B Alignment

Previous SEGMENT 7A and 7B

Las Vegas

Jean

SEGMENT 5ALT B

N

e

v

a d

a

C

a

l

i f

o

r

n

i

a

Sloan

Enterprise

Primm

SEGMENT 6 ALT B

Previous SEGMENT 7C

Previous SEGMENT

6C Central A and B

Figure 2. Location Of Alignment Alternatives Within HUC-8 Watershed

LegendHUC 8 Digit Subbasin

Las Vegas Wash

Watershed

0 5 10 15 20 25

Miles

Las Vegas Wash Watershed

F-I.5-39
Las Vegas

Jean

N

e

v

a d

a

C

a

l

i f

o

r

n

i

a

Sloan

Enterprise

Primm

Figure 3. Location of Study Area

Legend

Las Vegas Wash

Watershed

0 5 10 15 20 25

Miles

HUC 8 Digit Subbasin

Study Area

Las Vegas Wash Watershed

F-I.5-40
Las Vegas

Jean

N

e

v

a d

a

C

a

l

i f

o

r

n

i

a

Sloan

Enterprise

Primm

37

38

39

40

41

Figure 4. Location of Study Area Within HUC-8 / HUC-12 Watersheds

Las Vegas Wash

Watershed

0 5 10 15 20 25

Miles

LegendHUC 8 Digit Subbasin

Study AreaLas Vegas Wash WatershedHUC 12 Digit Subwatershed37 - Town of Sloan38 - Town of Arden39 - Duck Creek40 - Tropicana Wash41 - City of Las Vegas-Las Vegas Wash

F-I.5-41
Exhibit A. Figure 5. Typical examples of field indicators of active surface water flow and Ordinary High Water Marks found within ephemerals drainages occurring within the 

DesertXpress Project Study Area. F-I.5-42
Exhibit A. Figure 6. Typical examples of field indicators of active surface water flow and Ordinary High Water Marks found within ephemerals drainages occurring within the 

DesertXpress Project Study Area. F-I.5-43
Exhibit A. Figure 7. Typical examples of field indicators of active surface water flow and Ordinary High Water Marks found within ephemerals drainages occurring within the 

DesertXpress Project Study Area. F-I.5-44
Exhibit A. Figure 8. Typical examples of field indicators of active surface water flow and Ordinary High Water Marks found within ephemerals drainages occurring within the 

DesertXpress Project Study Area. F-I.5-45
Exhibit A. Figure 9. Typical examples of field indicators of active surface water flow and Ordinary High Water Marks found within ephemerals drainages occurring within the 

DesertXpress Project Study Area. F-I.5-46
Exhibit A. Figure 10. Typical examples of field indicators of active surface water flow and Ordinary High Water Marks found within ephemerals drainages occurring 

within the DesertXpress Project Study Area. F-I.5-47
Exhibit A. Figure 11. Typical examples of field indicators of active surface water flow and Ordinary High Water Marks found within ephemerals drainages occurring within the 

DesertXpress Project Study Area. F-I.5-48
Exhibit A. Figure 12. Typical examples of field indicators of active surface water flow and Ordinary High Water Marks found within ephemerals drainages occurring within the 

DesertXpress Project Study Area. F-I.5-49
Exhibit A. Figure 13. Manmade drainage connecting to ephemeral drainage within HUC 8 Las Vegas 

Wash Watershed / HUC 12 Town of Sloan Subwatershed 

Exhibit A. Figure 14. Manmade drainage connecting to ephemeral drainage within HUC 8 Las Vegas 

Wash Watershed / HUC 12 Town of Sloan Subwatershed

F-I.5-50
Exhibit A. Figure 15. Ephemeral drainage within HUC 8 Las Vegas Wash Watershed / HUC 12 

Town of Sloan Subwatershed

Exhibit A. Figure 16. Manmade drainage connecting to road culvert within HUC 8 Las Vegas Wash

Watershed / HUC 12 Town of Sloan Subwatershed

F-I.5-51
Exhibit A. Figure 17. Manmade drainage connecting to road culvert within HUC 8 Las Vegas 

Wash Watershed / HUC 12 Town of Sloan Subwatershed

Exhibit A. Figure 18. Manmade drainage connecting to road culvert within HUC 8 Las Vegas 

Wash Watershed / HUC 12 Town of Sloan Subwatershed 

F-I.5-52
Exhibit A. Figure 19. Manmade drainage connecting to road culvert within HUC 8 Las Vegas 

Wash Watershed / HUC 12, Town of Sloan Subwatershed

Exhibit A. Figure 20. Manmade drainage connecting to road culvert within HUC 8 Las Vegas 

Wash Watershed / HUC 12, Town of Sloan Subwatershed

F-I.5-53
Exhibit A. Figure 22. Manmade drainage connecting to ephemeral drainage within HUC 8 Las 

Vegas Watershed Wash / HUC 12 Town of Sloan Subwatershed

Exhibit A. Figure 23. Manmade drainage connecting to ephemeral drainage within HUC 8 Las 

Vegas Watershed Wash / HUC 12 Town of Sloan Subwatershed

F-I.5-54
Exhibit B

Field Data

Exhibit B1 Required Corps Waters Data Summary Table

Exhibit B2 Field Data* 

(Exhibit B2 provided on attached CD in PDF format.)

F-I.5-55
Exhibit B1

Required Corps Waters Data Summary Table

F-I.5-56
2/15/2011 12:38 PM

Waters_Name

Cowardin_Code HGM_Code

Area(acres)

Linear(ft)

WatersTypes

Latitude(dd nad83)

Longitude(dd nad83) Local_Waterway

width(OHWM)

HBG Data Field Point

Exhibit B1. Study Area Field Data for Areas Potentially Subject to Corps Jurisdiction, HUC-8 Las Vegas Wash Watershed, PreferrD-37-1 R6 RIVERINE 0.025903 352.6 NRPW 35.877964 -115.233649 Town of Sloan 3.20 37D1D-37-2 R6 RIVERINE 0.018175 263.9 NRPW 35.878678 -115.233233 Town of Sloan 3.00D-37-3 R6 RIVERINE 0.011081 160.9 NRPW 35.878945 -115.232851 Town of Sloan 3.00D-37-4 R6 RIVERINE 0.015186 220.5 NRPW 35.879045 -115.232115 Town of Sloan 3.00D-37-5 R6 RIVERINE 0.038685 561.7 NRPW 35.879092 -115.232525 Town of Sloan 3.00D-37-7 R6 RIVERINE 0.221648 965.5 NRPW 35.885425 -115.225507 Town of Sloan 10.00D-37-8 R6 RIVERINE 0.012257 410.7 NRPW 35.889421 -115.223178 Town of Sloan 1.30D-37-18 R6 RIVERINE 0.085973 374.5 NRPW 35.892545 -115.220865 Town of Sloan 10.00D-37-25 R6 RIVERINE 0.018905 305.0 NRPW 35.898664 -115.216580 Town of Sloan 2.70 37D5D-37-45 R6 RIVERINE 0.325895 1774.5 NRPW 35.934212 -115.191339 Town of Sloan 8.00D-37-46 R6 RIVERINE 0.004745 68.9 NRPW 35.932887 -115.192141 Town of Sloan 3.00D-37-47 R6 RIVERINE 0.154676 2245.9 NRPW 35.926199 -115.196701 Town of Sloan 3.00D-37-48 R6 RIVERINE 1.242528 3608.3 NRPW 35.903009 -115.212979 Town of Sloan 15.00D-37-55 R6 RIVERINE 0.004043 58.7 NRPW 35.886265 -115.225889 Town of Sloan 3.00D-37-56 R6 RIVERINE 0.011102 161.2 NRPW 35.880020 -115.230963 Town of Sloan 3.00D-37-59 R6 RIVERINE 0.041024 178.7 NRPW 35.883952 -115.226761 Town of Sloan 10.00D-37-60 R6 RIVERINE 0.005331 77.4 NRPW 35.885817 -115.224867 Town of Sloan 3.00D-37-65 R6 RIVERINE 0.059573 103.8 NRPW 35.950254 -115.182943 Town of Sloan 25.00D-37-66 R6 RIVERINE 0.332989 483.5 NRPW 35.949601 -115.183252 Town of Sloan 30.00D-37-67 R6 RIVERINE 0.029289 184.9 NRPW 35.947882 -115.183353 Town of Sloan 6.90 37MD2D-37-68 R6 RIVERINE 0.675039 976.9 NRPW 35.946586 -115.183724 Town of Sloan 30.10 37M3D-37-69 R6 RIVERINE 0.203159 1106.2 NRPW 35.944064 -115.184695 Town of Sloan 8.00 37MD9D-37-71 R6 RIVERINE 0.075161 327.4 NRPW 35.940047 -115.187513 Town of Sloan 10.00D-37-72 R6 RIVERINE 0.014862 107.9 NRPW 35.939471 -115.188081 Town of Sloan 6.00D-37-73 R6 RIVERINE 0.252342 549.6 NRPW 35.939887 -115.187098 Town of Sloan 20.00D-37-74 R6 RIVERINE 0.004986 72.4 NRPW 35.949807 -115.183649 Town of Sloan 3.00D-37-75 R6 RIVERINE 0.010062 146.1 NRPW 35.940688 -115.186977 Town of Sloan 3.00D-37-76 R6 RIVERINE 0.168733 245.0 NRPW 35.943000 -115.185228 Town of Sloan 30.00 37M10D-37-77 R6 RIVERINE 0.013113 190.4 NRPW 35.925353 -115.197513 Town of Sloan 3.00D-37-79 R6 RIVERINE 0.041667 605.0 NRPW 35.894414 -115.219772 Town of Sloan 3.00 37MD8D-37-80 R6 RIVERINE 0.007441 216.1 NRPW 35.876315 -115.235396 Town of Sloan 1.50D-37-81 R6 RIVERINE 0.024787 399.9 NRPW 35.896261 -115.218203 Town of Sloan 2.70 37D7D-37-82 R6 RIVERINE 0.087009 3790.1 NRPW 35.911727 -115.206926 Town of Sloan 1.00 37M4

ed 

Route Drainages, DesertXpress Project

J:\DesertXpress\Revised JD Spreadsheets 2-2-11\GWB Formatted 02 14 11\Las_Vegas_Wash r2 110215gwb Las_Vegas_Wash Page 1 of 5

F-I.5-57
2/15/2011 12:38 PM

Waters_Name

Cowardin_Code HGM_Code

Area(acres)

Linear(ft)

WatersTypes

Latitude(dd nad83)

Longitude(dd nad83) Local_Waterway

width(OHWM)

HBG Data Field Point

Exhibit B1. Study Area Field Data for Areas Potentially Subject to Corps Jurisdiction, HUC-8 Las Vegas Wash Watershed, Preferred Route Drainages, DesertXpress Project

D-37-83 R6 RIVERINE 0.623623 905.5 NRPW 35.941570 -115.186058 Town of Sloan 30.00D-37-82B R6 RIVERINE 0.017984 783.4 NRPW 35.908706 -115.209322 Town of Sloan 1.00D-37-90 R6 RIVERINE 0.547521 1590.0 NRPW 35.896901 -115.217301 Town of Sloan 15.00D-37-91 R6 RIVERINE 0.041481 602.3 NRPW 35.890582 -115.222167 Town of Sloan 3.00D-37-92 R6 RIVERINE 0.009743 424.4 NRPW 35.881835 -115.227860 Town of Sloan 1.00D-38-1 R6 RIVERINE 0.020964 304.4 NRPW 35.951746 -115.183015 Town of Arden 3.00D-38-2 R6 RIVERINE 0.019855 288.3 NRPW 35.952029 -115.183092 Town of Arden 3.00D-38-3 R6 RIVERINE 0.008182 118.8 NRPW 35.951979 -115.183307 Town of Arden 3.00D-38-5 R6 RIVERINE 0.009522 207.4 NRPW 35.966888 -115.182475 Town of Arden 2.00D-38-6 R6 RIVERINE 0.011063 481.9 NRPW 35.978791 -115.182238 Town of Arden 1.00D-38-7 R6 RIVERINE 0.003783 164.8 NRPW 35.979110 -115.182065 Town of Arden 1.00D-38-10 R6 RIVERINE 0.191804 278.5 NRPW 35.998438 -115.181372 Town of Arden 30.00D-38-11 R6 RIVERINE 0.009690 140.7 NRPW 35.999110 -115.181486 Town of Arden 3.00D-38-12 R6 RIVERINE 0.012080 175.4 NRPW 36.000227 -115.181417 Town of Arden 3.00D-38-13 R6 RIVERINE 0.006671 145.3 NRPW 36.000282 -115.181455 Town of Arden 2.00D-38-14 R6 RIVERINE 0.004674 101.8 NRPW 36.000622 -115.181553 Town of Arden 2.00D-38-15 R6 RIVERINE 0.029821 129.9 NRPW 36.000843 -115.181457 Town of Arden 10.00D-38-20 R6 RIVERINE 0.037176 269.9 NRPW 36.007242 -115.181181 Town of Arden 6.00D-38-21 R6 RIVERINE 0.012397 180.0 NRPW 36.018883 -115.181334 Town of Arden 3.00D-38-25 R6 RIVERINE 0.005028 219.0 NRPW 36.023180 -115.181370 Town of Arden 1.00 38D2D-38-30 R6 RIVERINE 0.027583 240.3 NRPW 36.024871 -115.181394 Town of Arden 5.00 38D6D-38-31 R6 RIVERINE 0.002750 119.8 NRPW 36.024737 -115.181575 Town of Arden 1.00 38D5D-38-32 R6 RIVERINE 0.004534 197.5 NRPW 36.025673 -115.181478 Town of Arden 1.00 38D8D-38-33 R6 RIVERINE 0.025269 366.9 NRPW 36.025581 -115.181160 Town of Arden 3.00D-38-34 R6 RIVERINE 0.040517 588.3 NRPW 36.024106 -115.181122 Town of Arden 3.00D-38-37 R6 RIVERINE 0.009380 136.2 NRPW 35.999810 -115.181469 Town of Arden 3.00D-38-40 R6 RIVERINE 0.005202 226.6 NRPW 35.980603 -115.182135 Town of Arden 1.00D-38-42 R6 RIVERINE 0.004380 95.4 NRPW 35.975147 -115.181841 Town of Arden 2.00D-38-44 R6 RIVERINE 0.003861 168.2 NRPW 35.966055 -115.182625 Town of Arden 1.00D-38-45 R6 RIVERINE 0.017190 249.6 NRPW 36.022831 -115.181082 Town of Arden 3.00D-38-47 R6 RIVERINE 0.007872 114.3 NRPW 36.018897 -115.181430 Town of Arden 3.00D-38-48 R6 RIVERINE 0.006067 88.1 NRPW 36.002028 -115.181044 Town of Arden 3.00D-38-49 R6 RIVERINE 0.018602 270.1 NRPW 36.001480 -115.183004 Town of Arden 3.00

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F-I.5-58
2/15/2011 12:38 PM

Waters_Name

Cowardin_Code HGM_Code

Area(acres)

Linear(ft)

WatersTypes

Latitude(dd nad83)

Longitude(dd nad83) Local_Waterway

width(OHWM)

HBG Data Field Point

Exhibit B1. Study Area Field Data for Areas Potentially Subject to Corps Jurisdiction, HUC-8 Las Vegas Wash Watershed, Preferred Route Drainages, DesertXpress Project

D-38-50 R6 RIVERINE 0.017135 248.8 NRPW 36.001122 -115.183038 Town of Arden 3.00D-38-51 R6 RIVERINE 0.016811 244.1 NRPW 36.002222 -115.181244 Town of Arden 3.00D-38-52 R6 RIVERINE 0.002163 31.4 NRPW 36.002082 -115.181058 Town of Arden 3.00D-38-53 R6 RIVERINE 0.018602 270.1 NRPW 36.001654 -115.181071 Town of Arden 3.00D-38-54 R6 RIVERINE 0.005599 81.3 NRPW 36.002247 -115.181055 Town of Arden 3.00D-38-55 R6 RIVERINE 0.053168 772.0 NRPW 36.000214 -115.181224 Town of Arden 3.00D-38-56 R6 RIVERINE 0.010138 220.8 NRPW 35.972548 -115.181859 Town of Arden 2.00D-38-57 R6 RIVERINE 0.003843 55.8 NRPW 35.965841 -115.182657 Town of Arden 3.00D-38-59 R6 RIVERINE 0.001410 30.7 NRPW 35.968325 -115.182055 Town of Arden 2.00D-38-60 R6 RIVERINE 0.002998 130.6 NRPW 35.980891 -115.181663 Town of Arden 1.00D-38-70 R6 RIVERINE 0.004589 199.9 NRPW 36.022988 -115.181410 Town of Arden 1.00D-38-71 R6 RIVERINE 0.004320 188.2 NRPW 36.022565 -115.181412 Town of Arden 1.00 38D1D-38-72 R6 RIVERINE 0.084532 1227.4 NRPW 36.017171 -115.181362 Town of Arden 3.00D-38-73 R6 RIVERINE 0.002594 113.0 NRPW 36.019313 -115.181441 Town of Arden 1.00D-38-74 R6 RIVERINE 0.090310 1311.3 NRPW 36.020681 -115.181045 Town of Arden 3.00D-38-75 R6 RIVERINE 0.004656 202.8 NRPW 36.022037 -115.181393 Town of Arden 1.00D-38-76 R6 RIVERINE 0.004293 187.0 NRPW 36.022144 -115.181402 Town of Arden 1.00D-38-77 R6 RIVERINE 0.004201 183.0 NRPW 36.022378 -115.181396 Town of Arden 1.00D-38-78 R6 RIVERINE 0.002324 202.5 NRPW 36.024190 -115.181470 Town of Arden 0.50 38D3D-38-79 R6 RIVERINE 0.002312 201.4 NRPW 36.024248 -115.181445 Town of Arden 0.50 38D4D-38-80 R6 RIVERINE 0.002374 206.8 NRPW 36.024346 -115.181473 Town of Arden 0.50D-38-81 R6 RIVERINE 0.005115 222.8 NRPW 36.025421 -115.181534 Town of Arden 1.00 38D7D-38-82 R6 RIVERINE 0.037955 551.1 NRPW 36.001489 -115.184644 Town of Arden 3.00D-38-83 R6 RIVERINE 0.036804 534.4 NRPW 36.002205 -115.184596 Town of Arden 3.00D-38-84 R6 RIVERINE 0.037424 543.4 NRPW 36.002247 -115.182540 Town of Arden 3.00D-38-85 R6 RIVERINE 0.022803 331.1 NRPW 36.002376 -115.182187 Town of Arden 3.00D-39-3 R6 RIVERINE 0.057810 419.7 NRPW 36.037465 -115.181789 Duck Creek 6.00 39D21D-39-4 R6 RIVERINE 0.008003 58.1 NRPW 36.039237 -115.181334 Duck Creek 6.00D-39-5 R6 RIVERINE 0.015455 224.4 NRPW 36.040349 -115.181254 Duck Creek 3.00D-39-6 R6 RIVERINE 0.003939 57.2 NRPW 36.040333 -115.181351 Duck Creek 3.00D-39-7 R6 RIVERINE 0.016494 239.5 NRPW 36.049787 -115.181532 Duck Creek 3.00D-39-8 R6 RIVERINE 0.032190 233.7 NRPW 36.056942 -115.181535 Duck Creek 6.00D-39-9 R6 RIVERINE 0.003444 50.0 NRPW 36.056970 -115.181270 Duck Creek 3.00

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F-I.5-59
2/15/2011 12:38 PM

Waters_Name

Cowardin_Code HGM_Code

Area(acres)

Linear(ft)

WatersTypes

Latitude(dd nad83)

Longitude(dd nad83) Local_Waterway

width(OHWM)

HBG Data Field Point

Exhibit B1. Study Area Field Data for Areas Potentially Subject to Corps Jurisdiction, HUC-8 Las Vegas Wash Watershed, Preferred Route Drainages, DesertXpress Project

D-39-10 R6 RIVERINE 0.005227 75.9 NRPW 36.057223 -115.181218 Duck Creek 3.00D-39-11 R6 RIVERINE 0.015023 81.8 NRPW 36.058907 -115.181439 Duck Creek 8.00D-39-12 R6 RIVERINE 0.068685 997.3 NRPW 36.058749 -115.181291 Duck Creek 3.00D-39-13 R6 RIVERINE 0.047989 348.4 NRPW 36.062890 -115.181902 Duck Creek 6.00D-39-16 R6 RIVERINE 0.003492 50.7 NRPW 36.055298 -115.181233 Duck Creek 3.00D-39-17 R6 RIVERINE 0.091598 1330.0 NRPW 36.055087 -115.181138 Duck Creek 3.00D-39-21 R6 RIVERINE 0.004112 59.7 NRPW 36.041021 -115.181323 Duck Creek 3.00D-39-23 R6 RIVERINE 0.019780 287.2 NRPW 36.028090 -115.181236 Duck Creek 3.00D-39-24 R6 RIVERINE 0.043326 629.1 NRPW 36.026900 -115.181169 Duck Creek 3.00D-39-25 R6 RIVERINE 0.050165 364.2 NRPW 36.053456 -115.181531 Duck Creek 6.00D-39-26 R6 RIVERINE 0.045317 658.0 NRPW 36.039370 -115.181237 Duck Creek 3.00D-39-30 R6 RIVERINE 0.003147 45.7 NRPW 36.032788 -115.181206 Duck Creek 3.00D-39-32 R6 RIVERINE 0.003479 757.8 NRPW 36.052093 -115.185710 Duck Creek 0.20D-39-40 R6 RIVERINE 0.250413 3636.0 NRPW 36.033479 -115.181210 Duck Creek 3.00D-39-41 R6 RIVERINE 0.001853 26.9 NRPW 36.035427 -115.181271 Duck Creek 3.00D-39-42 R6 RIVERINE 0.005985 86.9 NRPW 36.031938 -115.181378 Duck Creek 3.00D-39-43 R6 RIVERINE 0.021670 629.3 NRPW 36.032898 -115.182348 Duck Creek 1.50 39D11D-39-44 R6 RIVERINE 0.005305 231.1 NRPW 36.032949 -115.183060 Duck Creek 1.00D-39-45 R6 RIVERINE 0.009012 261.7 NRPW 36.033095 -115.182971 Duck Creek 1.50 39D13D-39-46 R6 RIVERINE 0.014481 630.8 NRPW 36.033152 -115.182394 Duck Creek 1.00 39D14D-39-47 R6 RIVERINE 0.015452 673.1 NRPW 36.033558 -115.182295 Duck Creek 1.00 39D15D-39-48 R6 RIVERINE 0.014137 615.8 NRPW 36.034005 -115.182344 Duck Creek 1.00 39D16D-39-49 R6 RIVERINE 0.015115 658.4 NRPW 36.036577 -115.182325 Duck Creek 1.00 39D17D-39-50 R6 RIVERINE 0.041288 599.5 NRPW 36.037182 -115.182335 Duck Creek 3.00 39D19D-40-1 R6 RIVERINE 0.013354 193.9 NRPW 36.085226 -115.181614 Tropicana Wash 3.00D-40-2 R6 RIVERINE 0.144752 2101.8 NRPW 36.095952 -115.181073 Tropicana Wash 3.00D-40-3 R6 RIVERINE 0.008347 121.2 NRPW 36.098824 -115.181289 Tropicana Wash 3.00D-40-4 R6 RIVERINE 0.001398 20.3 NRPW 36.109722 -115.181038 Tropicana Wash 3.00D-40-5 R6 RIVERINE 0.001405 20.4 NRPW 36.106993 -115.181046 Tropicana Wash 3.00D-40-6 R6 RIVERINE 0.006880 99.9 NRPW 36.089755 -115.181759 Tropicana Wash 3.00D-40-7 R6 RIVERINE 0.082287 298.7 NRPW 36.088305 -115.181659 Tropicana Wash 12.00D-40-8 R6 RIVERINE 0.002548 37.0 NRPW 36.088542 -115.181095 Tropicana Wash 3.00D-40-10 R6 RIVERINE 0.027410 99.5 NRPW 36.077738 -115.181751 Tropicana Wash 12.00

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F-I.5-60
2/15/2011 12:38 PM

Waters_Name

Cowardin_Code HGM_Code

Area(acres)

Linear(ft)

WatersTypes

Latitude(dd nad83)

Longitude(dd nad83) Local_Waterway

width(OHWM)

HBG Data Field Point

Exhibit B1. Study Area Field Data for Areas Potentially Subject to Corps Jurisdiction, HUC-8 Las Vegas Wash Watershed, Preferred Route Drainages, DesertXpress Project

D-40-11 R6 RIVERINE 0.029236 424.5 NRPW 36.080817 -115.181226 Tropicana Wash 3.00D-40-12 R6 RIVERINE 0.007211 104.7 NRPW 36.080341 -115.181194 Tropicana Wash 3.00D-40-13 R6 RIVERINE 0.003988 57.9 NRPW 36.071828 -115.181142 Tropicana Wash 3.00D-40-14 R6 RIVERINE 0.010723 155.7 NRPW 36.065368 -115.181097 Tropicana Wash 3.00D-40-15 R6 RIVERINE 0.023113 83.9 NRPW 36.084409 -115.181454 Tropicana Wash 12.00D-40-16 R6 RIVERINE 0.007087 102.9 NRPW 36.103114 -115.181188 Tropicana Wash 3.00D-40-17 R6 RIVERINE 0.073616 1068.9 NRPW 36.088348 -115.183556 Tropicana Wash 3.00D-40-18 R6 RIVERINE 0.000792 11.5 NRPW 36.088658 -115.181895 Tropicana Wash 3.00D-40-19 R6 RIVERINE 0.075833 1101.1 NRPW 36.087448 -115.184482 Tropicana Wash 3.00D-40-20 R6 RIVERINE 0.001391 20.2 NRPW 36.089775 -115.181209 Tropicana Wash 3.00D-40-21 R6 RIVERINE 0.057039 828.2 NRPW 36.089096 -115.183141 Tropicana Wash 3.00D-40-22 R6 RIVERINE 0.013974 202.9 NRPW 36.089696 -115.181921 Tropicana Wash 3.00D-40-23 R6 RIVERINE 0.021371 310.3 NRPW 36.071306 -115.181152 Tropicana Wash 3.00D-40-24 R6 RIVERINE 0.029683 215.5 NRPW 36.064787 -115.181602 Tropicana Wash 6.00D-40-25 R6 RIVERINE 0.001233 17.9 NRPW 36.070768 -115.181154 Tropicana Wash 3.00

8.090163 62875.5 Totals:

J:\DesertXpress\Revised JD Spreadsheets 2-2-11\GWB Formatted 02 14 11\Las_Vegas_Wash r2 110215gwb Las_Vegas_Wash Page 5 of 5

F-I.5-61
Exhibit B2

Field Data

(See attached CD in PDF format.)

F-I.5-62
F-I.5-63
F-I.5-64
F-I.5-65
F-I.5-66
F-I.5-67
F-I.5-68
F-I.5-69
F-I.5-70
F-I.5-71
F-I.5-72
F-I.5-73
F-I.5-74
F-I.5-75
F-I.5-76
F-I.5-77
F-I.5-78
F-I.5-79
F-I.5-80
F-I.5-81
F-I.5-82
Exhibit B2 

DesertXpress Field Data 

For

Las Vegas Wash Watershed 

(HUC 15010015) 

HBG 

Watershed 

Number 

HUC 12 Watershed Name 

HBG 

Field

Data 

ICF Jones 

& Stokes 

Field Data 

Comments 

37 Town of Sloan Yes Yes 

38 Town of Arden Yes Yes 

Delineated by HBG using adjacent 

watershed data. 

39 Duck Creek Yes Yes 

40 Tropicana Wash No Yes Delineated by HBG using adjacent 

watershed data.

41 City of Las Vegas-Las Vegas 

Wash No Yes 

Only northernmost possible station 

locations would be in this watershed. 

Urban Drainage features. Delineated by 

HBG using adjacent watershed data. 

*

F-I.5-83
Huffman-Broadway Group 

Field Data Forms 

For DesertXpress

HUC 12 Watershed Town of Sloan

Within Las Vegas Wash Watershed 

(HUC 15010015) 

HBG Watershed ID # 37 

F-I.5-84
Huffman-Broadway Group

Field Data Forms

For DesertXpress

HUC 12 Watershed Town of Sloan

Within Las Vegas Wash Watershed

(HUC 15010015)

HBG Watershed ID # 37

F-I.5-85
F-I.5-86
F-I.5-87
F-I.5-88

*

*
F-I.5-89

*

*

*

*
F-I.5-90
F-I.5-91
F-I.5-92
F-I.5-93
F-I.5-94
F-I.5-95
F-I.5-96
F-I.5-97
F-I.5-98
F-I.5-99
F-I.5-100
F-I.5-101
F-I.5-102
F-I.5-103
F-I.5-104
F-I.5-105
F-I.5-106
F-I.5-107
Exhibit B2 

DesertXpress Field Data 

For

Las Vegas Wash Watershed 

(HUC 15010015) 

HBG 

Watershed 

Number 

HUC 12 Watershed Name 

HBG 

Field

Data 

ICF Jones 

& Stokes 

Field Data 

Comments 

37 Town of Sloan Yes Yes 

38 Town of Arden Yes Yes 

Delineated by HBG using adjacent 

watershed data. 

39 Duck Creek Yes Yes 

40 Tropicana Wash No Yes Delineated by HBG using adjacent 

watershed data.

41 City of Las Vegas-Las Vegas 

Wash No Yes 

Only northernmost possible station 

locations would be in this watershed. 

Urban Drainage features. Delineated by 

HBG using adjacent watershed data. 

*

F-I.5-108
F-I.5-109
F-I.5-110
F-I.5-111
F-I.5-112
F-I.5-113
F-I.5-114
F-I.5-115
F-I.5-116
F-I.5-117
F-I.5-118
F-I.5-119
F-I.5-120
F-I.5-121
F-I.5-122
F-I.5-123
F-I.5-124
F-I.5-125
F-I.5-126
F-I.5-127
F-I.5-128
F-I.5-129
F-I.5-130
F-I.5-131
F-I.5-132
F-I.5-133
F-I.5-134
F-I.5-135
Exhibit B2 

DesertXpress Field Data 

For

Las Vegas Wash Watershed 

(HUC 15010015) 

HBG 

Watershed 

Number 

HUC 12 Watershed Name 

HBG 

Field

Data 

ICF Jones 

& Stokes 

Field Data 

Comments 

37 Town of Sloan Yes Yes 

38 Town of Arden Yes Yes 

Delineated by HBG using adjacent 

watershed data. 

39 Duck Creek Yes Yes 

40 Tropicana Wash No Yes Delineated by HBG using adjacent 

watershed data.

41 City of Las Vegas-Las Vegas 

Wash No Yes 

Only northernmost possible station 

locations would be in this watershed. 

Urban Drainage features. Delineated by 

HBG using adjacent watershed data. 

*

F-I.5-136
F-I.5-137
F-I.5-138
F-I.5-139
F-I.5-140

*

*

*
F-I.5-141

*

*

*

*

*

*

*
F-I.5-142
F-I.5-143
F-I.5-144
F-I.5-145
F-I.5-146
F-I.5-147
F-I.5-148
F-I.5-149
F-I.5-150
F-I.5-151
F-I.5-152
F-I.5-153
F-I.5-154
F-I.5-155
F-I.5-156
F-I.5-157
F-I.5-158
Exhibit B2 

DesertXpress Field Data 

For

Las Vegas Wash Watershed 

(HUC 15010015) 

HBG 

Watershed 

Number 

HUC 12 Watershed Name 

HBG 

Field

Data 

ICF Jones 

& Stokes 

Field Data 

Comments 

37 Town of Sloan Yes Yes 

38 Town of Arden Yes Yes 

Delineated by HBG using adjacent 

watershed data. 

39 Duck Creek Yes Yes 

40 Tropicana Wash No Yes Delineated by HBG using adjacent 

watershed data.

41 City of Las Vegas-Las Vegas 

Wash No Yes 

Only northernmost possible station 

locations would be in this watershed. 

Urban Drainage features. Delineated by 

HBG using adjacent watershed data. 

*

F-I.5-159
Huffman-Broadway Group

Field Data Forms

For DesertXpress

HUC 12 Watershed Duck Creek

Within Las Vegas Wash Watershed

(HUC 15010015)

HBG Watershed ID # 39

F-I.5-160
F-I.5-161
F-I.5-162
F-I.5-163
F-I.5-164
F-I.5-165
F-I.5-166
F-I.5-167
F-I.5-168
F-I.5-169
F-I.5-170
F-I.5-171
F-I.5-172
Exhibit B2 

DesertXpress Field Data 

For

Las Vegas Wash Watershed 

(HUC 15010015) 

HBG 

Watershed 

Number 

HUC 12 Watershed Name 

HBG 

Field

Data 

ICF Jones 

& Stokes 

Field Data 

Comments 

37 Town of Sloan Yes Yes 

38 Town of Arden Yes Yes 

Delineated by HBG using adjacent 

watershed data. 

39 Duck Creek Yes Yes 

40 Tropicana Wash No Yes Delineated by HBG using adjacent 

watershed data.

41 City of Las Vegas-Las Vegas 

Wash No Yes 

Only northernmost possible station 

locations would be in this watershed. 

Urban Drainage features. Delineated by 

HBG using adjacent watershed data. 

*

F-I.5-173
F-I.5-174
F-I.5-175
F-I.5-176
F-I.5-177
F-I.5-178
F-I.5-179
F-I.5-180
Exhibit B2 

DesertXpress Field Data 

For

Las Vegas Wash Watershed 

(HUC 15010015) 

HBG 

Watershed 

Number 

HUC 12 Watershed Name 

HBG 

Field

Data 

ICF Jones 

& Stokes 

Field Data 

Comments 

37 Town of Sloan Yes Yes 

38 Town of Arden Yes Yes 

Delineated by HBG using adjacent 

watershed data. 

39 Duck Creek Yes Yes 

40 Tropicana Wash No Yes Delineated by HBG using adjacent 

watershed data.

41 City of Las Vegas-Las Vegas 

Wash No Yes 

Only northernmost possible station 

locations would be in this watershed. 

Urban Drainage features. Delineated by 

HBG using adjacent watershed data. 

*

F-I.5-181
F-I.5-182
F-I.5-183
F-I.5-184
F-I.5-185
F-I.5-186
F-I.5-187
F-I.5-188
F-I.5-189
F-I.5-190
F-I.5-191
F-I.5-192
F-I.5-193
F-I.5-194
F-I.5-195
F-I.5-196
F-I.5-197
F-I.5-198
F-I.5-199
F-I.5-200
F-I.5-201
F-I.5-202
Exhibit B2 

DesertXpress Field Data 

For

Las Vegas Wash Watershed 

(HUC 15010015) 

HBG 

Watershed 

Number 

HUC 12 Watershed Name 

HBG 

Field

Data 

ICF Jones 

& Stokes 

Field Data 

Comments 

37 Town of Sloan Yes Yes 

38 Town of Arden Yes Yes 

Delineated by HBG using adjacent 

watershed data. 

39 Duck Creek Yes Yes 

40 Tropicana Wash No Yes Delineated by HBG using adjacent 

watershed data.

41 City of Las Vegas-Las Vegas 

Wash No Yes 

Only northernmost possible station 

locations would be in this watershed. 

Urban Drainage features. Delineated by 

HBG using adjacent watershed data. 

*

F-I.5-203
ICF Jones & Stokes 

Wetland Determination Data Forms – 

Arid West Region 

For DesertXpress

HUC 12 Watershed City of Las VegasLas Vegas Wash

Within Las Vegas Wash Watershed 

(HUC 15010015) 

HBG Watershed ID # 41 

F-I.5-204
F-I.5-205
F-I.5-206
Exhibit C

Maps of Potential Jurisdictional Areas

F-I.5-207
HUC 8 

Las Vegas Wash

HUC 8 

Ivanpah-Pahrump Valleys

D-37-7

D-37-5

D-37-92

D-37-1

D-37-2

D-37-4

D-37-80

D-37-3

D-37-59 D-37-56

D-37-60

D-37-55

10 ft. ____

 ____1 ft.

 ____

3.2 ft. ____

3 ft.

 ____1.5 ft.

 ____

3 ft.

 ____10 ft.

 ____3 ft.

0 200 400 600 800 1,000 Feet

Aerial Photography Dated 2008

HBGHuffman-Broadway Group, Inc. · 828 Mission Avenue · San Rafael, California · Phone (415) 925-2000 · Fax (415) 925-2006

Legend

Jurisdictional Delineation Study Area

Potential Corps Jurisdictional Area: 

OHWM width ___10 ft.

D-1-100 Ephemeral Drainage (with ID number

and )

Exhibit C. Areas Potentially Subject to Corps Jurisdiction Under Section 404 of the Clean Water Act, DesertXpress Project, HUC 8 Las Vegas Wash Watershed, Clark County, Nevada, Current Preferred Segment 5 Alt B, Map Sheet C250

Map Sheet Location

C251

C250

C252

PreferredSEGMENT 5Alt B

PreferredSEGMENT 6Alt B

PreviousSEGMENT 6CCentral A and B

Map Dated: January 28, 2011

(Corps field review 2-2011)

F-I.5-208
D-37-90 D-37-48 D-37-7

D-37-91

D-37-8 D-37-79

D-37-81 D-37-18

D-37-25 D-37-55

D-37-60

15 ft. ____

 ____

10 ft.

 ____3 ft. ____1.3 ft. ____2.7 ft. ____10 ft.

15 ft. ____

 ____

3 ft.

 ____

2.7 ft.

0 200 400 600 800 1,000 Feet

Aerial Photography Dated 2008

HBGHuffman-Broadway Group, Inc. · 828 Mission Avenue · San Rafael, California · Phone (415) 925-2000 · Fax (415) 925-2006

Legend

Jurisdictional Delineation Study Area

Potential Corps Jurisdictional Area: 

OHWM width ___10 ft.

D-1-100 Ephemeral Drainage (with ID number

and )

Exhibit C. Areas Potentially Subject to Corps Jurisdiction Under Section 404 of the Clean Water Act, DesertXpress Project, HUC 8 Las Vegas Wash Watershed, Clark County, Nevada, Current Preferred Segment 5 Alt B, Map Sheet C251

Map Sheet Location

C251

C252

C250

PreferredSEGMENT 5Alt B

PreferredSEGMENT 6Alt B

PreviousSEGMENT 6CCentral A and B

Map Dated: January 28, 2011

(Corps field review 2-2011)

F-I.5-209
D-37-48 D-37-82

D-37-82B

15 ft. ____

 ____1 ft. ____1 ft.

0 200 400 600 800 1,000 Feet

Aerial Photography Dated 2008

HBGHuffman-Broadway Group, Inc. · 828 Mission Avenue · San Rafael, California · Phone (415) 925-2000 · Fax (415) 925-2006

Legend

Jurisdictional Delineation Study Area

Potential Corps Jurisdictional Area: 

OHWM width ___10 ft.

D-1-100 Ephemeral Drainage (with ID number

and )

Exhibit C. Areas Potentially Subject to Corps Jurisdiction Under Section 404 of the Clean Water Act, DesertXpress Project, HUC 8 Las Vegas Wash Watershed, Clark County, Nevada, Current Preferred Segment 5 Alt B, Map Sheet C252

Map Sheet Location

C251

C252

C250

PreferredSEGMENT 5Alt B

PreferredSEGMENT 6Alt B

PreviousSEGMENT 6CCentral A and B

Map Dated: January 28, 2011

(Corps field review 2-2011)

F-I.5-210
Las Vegas Blvd South

D-37-82

1 ft. ____

0 200 400 600 800 1,000 Feet

Aerial Photography Dated 2008

HBGHuffman-Broadway Group, Inc. · 828 Mission Avenue · San Rafael, California · Phone (415) 925-2000 · Fax (415) 925-2006

Exhibit C. Areas Potentially Subject to Corps Jurisdiction Under Section 404 of the Clean Water Act, DesertXpress Project, HUC 8 Las Vegas Wash Watershed, Clark County, Nevada, Current Preferred Segments 6 Alt B and 6 Alt C, Map Sheet C253

Legend

Jurisdictional Delineation Study Area

Potential Corps Jurisdictional Area: 

OHWM width ___10 ft.

D-1-100 Ephemeral Drainage (with ID number

and )

PreferredSEGMENT 5Alt B

PreferredSEGMENT 6Alt B

PreviousSEGMENT 6CCentral A and B

Map Sheet Location

C278

C253

C253

C254

C255

RecentSEGMENT 6B

Map Dated: January 28, 2011

(Corps field review 2-2011)

F-I.5-211
Las Vegas Blvd South

D-37-47

D-37-77

3 ft. ____ ____

3 ft.

0 200 400 600 800 1,000 Feet

Aerial Photography Dated 2008

HBGHuffman-Broadway Group, Inc. · 828 Mission Avenue · San Rafael, California · Phone (415) 925-2000 · Fax (415) 925-2006

Exhibit C. Areas Potentially Subject to Corps Jurisdiction Under Section 404 of the Clean Water Act, DesertXpress Project, HUC 8 Las Vegas Wash Watershed, Clark County, Nevada, Current Preferred Segments 6 Alt B and 6 Alt C, Map Sheet C254

Legend

Jurisdictional Delineation Study Area

Potential Corps Jurisdictional Area: 

OHWM width ___10 ft.

D-1-100 Ephemeral Drainage (with ID number

and )

PreferredSEGMENT 5Alt B

PreferredSEGMENT 6Alt B

PreviousSEGMENT 6CCentral A and B

Map Sheet Location

C278

C253

C253

C254

C255

C256

RecentSEGMENT 6B

Map Dated: January 28, 2011

(Corps field review 2-2011)

F-I.5-212
Las Vegas Blvd South

Sloan Rd Paplinsky Pkwy

D-37-47

D-37-45 D-37-77

 ____3 ft.

8 ft. ____ ____3 ft.

0 200 400 600 800 1,000 Feet

Aerial Photography Dated 2008

HBGHuffman-Broadway Group, Inc. · 828 Mission Avenue · San Rafael, California · Phone (415) 925-2000 · Fax (415) 925-2006

Exhibit C. Areas Potentially Subject to Corps Jurisdiction Under Section 404 of the Clean Water Act, DesertXpress Project, HUC 8 Las Vegas Wash Watershed, Clark County, Nevada, Current Preferred Segments 6 Alt B and 6 Alt C, Map Sheet C255

Legend

Jurisdictional Delineation Study Area

Potential Corps Jurisdictional Area: 

OHWM width ___10 ft.

D-1-100 Ephemeral Drainage (with ID number

and )

PreferredSEGMENT 5Alt B

PreferredSEGMENT 6Alt B

PreviousSEGMENT 6CCentral A and B

Map Sheet Location

C278

C253

C256

C254

C255

C257

C253

RecentSEGMENT 6B

Map Dated: January 28, 2011

(Corps field review 2-2011)

F-I.5-213
Paplinsky Pkwy

D-37-45 D-37-73

D-37-71 D-37-72

D-37-46

8 ft. ____

 ____20 ft.

0 200 400 600 800 1,000 Feet

Aerial Photography Dated 2008

HBGHuffman-Broadway Group, Inc. · 828 Mission Avenue · San Rafael, California · Phone (415) 925-2000 · Fax (415) 925-2006

Exhibit C. Areas Potentially Subject to Corps Jurisdiction Under Section 404 of the Clean Water Act, DesertXpress Project, HUC 8 Las Vegas Wash Watershed, Clark County, Nevada, Current Preferred Segments 6 Alt B and 6 Alt C, Map Sheet C256

Legend

Jurisdictional Delineation Study Area

Potential Corps Jurisdictional Area: 

OHWM width ___10 ft.

D-1-100 Ephemeral Drainage (with ID number

and )

PreferredSEGMENT 5Alt B

PreferredSEGMENT 6Alt B

PreviousSEGMENT 6CCentral A and B

Map Sheet Location

C278

C253

C257

C256

C255

C254

C258

RecentSEGMENT 6B

Map Dated: January 28, 2011

(Corps field review 2-2011)

F-I.5-214
D-37-69

D-37-83

D-37-68

D-37-73

D-37-71

D-37-76

D-37-75

D-37-72

 ____

8 ft.

30 ft. ____ ____30.1 ft.

20 ft. ____

 ____

10 ft.

 ____3 ft.

30 ft. ____

0 200 400 600 800 1,000 Feet

Aerial Photography Dated 2008

HBGHuffman-Broadway Group, Inc. · 828 Mission Avenue · San Rafael, California · Phone (415) 925-2000 · Fax (415) 925-2006

Exhibit C. Areas Potentially Subject to Corps Jurisdiction Under Section 404 of the Clean Water Act, DesertXpress Project, HUC 8 Las Vegas Wash Watershed, Clark County, Nevada, Current Preferred Segments 6 Alt B and 6 Alt C, Map Sheet C257

Legend

Jurisdictional Delineation Study Area

Potential Corps Jurisdictional Area: 

OHWM width ___10 ft.

D-1-100 Ephemeral Drainage (with ID number

and )

PreferredSEGMENT 5Alt B

PreferredSEGMENT 6Alt B

PreviousSEGMENT 6CCentral A and B

Map Sheet Location

C278

C253

C258

C257

C256

C255

C259

RecentSEGMENT 6B

Map Dated: January 28, 2011

(Corps field review 2-2011)

F-I.5-215
D-37-68

D-37-66

D-38-1

D-38-2 D-37-67

D-37-65

D-37-74

 ____

30.1 ft. ____30 ft. ____

3 ft.

 ____

6.9 ft. ____3 ft.

0 200 400 600 800 1,000 Feet

Aerial Photography Dated 2008

HBGHuffman-Broadway Group, Inc. · 828 Mission Avenue · San Rafael, California · Phone (415) 925-2000 · Fax (415) 925-2006

Exhibit C. Areas Potentially Subject to Corps Jurisdiction Under Section 404 of the Clean Water Act, DesertXpress Project, HUC 8 Las Vegas Wash Watershed, Clark County, Nevada, Current Preferred Segments 6 Alt B and 6 Alt C, Map Sheet C258

Legend

Jurisdictional Delineation Study Area

Potential Corps Jurisdictional Area: 

OHWM width ___10 ft.

D-1-100 Ephemeral Drainage (with ID number

and )

PreferredSEGMENT 5Alt B

PreferredSEGMENT 6Alt B

PreviousSEGMENT 6CCentral A and B

Map Sheet Location

C278

C253

C258

C259

C257

C256

C260

RecentSEGMENT 6B

Map Dated: January 28, 2011

(Corps field review 2-2011)

F-I.5-216
Paplinsky Pkwy

0 200 400 600 800 1,000 Feet

Aerial Photography Dated 2008

HBGHuffman-Broadway Group, Inc. · 828 Mission Avenue · San Rafael, California · Phone (415) 925-2000 · Fax (415) 925-2006

Exhibit C. Areas Potentially Subject to Corps Jurisdiction Under Section 404 of the Clean Water Act, DesertXpress Project, HUC 8 Las Vegas Wash Watershed, Clark County, Nevada, Current Preferred Segments 6 Alt B and 6 Alt C, Map Sheet C259

Legend

Jurisdictional Delineation Study Area

Potential Corps Jurisdictional Area: 

OHWM width ___10 ft.

D-1-100 Ephemeral Drainage (with ID number

and )

PreferredSEGMENT 5Alt B

PreferredSEGMENT 6Alt B

PreviousSEGMENT 6CCentral A and B

Map Sheet Location

C278

C253

C258

C260

C259

C257

C261

RecentSEGMENT 6B

Map Dated: January 28, 2011

(Corps field review 2-2011)

F-I.5-217
D-38-5 D-38-44

D-38-59

 ____2 ft.

 ____1 ft.

0 200 400 600 800 1,000 Feet

Aerial Photography Dated 2008

HBGHuffman-Broadway Group, Inc. · 828 Mission Avenue · San Rafael, California · Phone (415) 925-2000 · Fax (415) 925-2006

Exhibit C. Areas Potentially Subject to Corps Jurisdiction Under Section 404 of the Clean Water Act, DesertXpress Project, HUC 8 Las Vegas Wash Watershed, Clark County, Nevada, Current Preferred Segments 6 Alt B and 6 Alt C, Map Sheet C260

Legend

Jurisdictional Delineation Study Area

Potential Corps Jurisdictional Area: 

OHWM width ___10 ft.

D-1-100 Ephemeral Drainage (with ID number

and )

PreferredSEGMENT 5Alt B

PreferredSEGMENT 6Alt B

PreviousSEGMENT 6CCentral A and B

Map Sheet Location

C278

C253

C261

C260

C259

C258

C262

RecentSEGMENT 6B

Map Dated: January 28, 2011

(Corps field review 2-2011)

F-I.5-218
D-38-6

D-38-56

D-38-7

D-38-42

 ____1 ft. ____2 ft.

0 200 400 600 800 1,000 Feet

Aerial Photography Dated 2008

HBGHuffman-Broadway Group, Inc. · 828 Mission Avenue · San Rafael, California · Phone (415) 925-2000 · Fax (415) 925-2006

Exhibit C. Areas Potentially Subject to Corps Jurisdiction Under Section 404 of the Clean Water Act, DesertXpress Project, HUC 8 Las Vegas Wash Watershed, Clark County, Nevada, Current Preferred Segments 6 Alt B and 6 Alt C, Map Sheet C261

Legend

Jurisdictional Delineation Study Area

Potential Corps Jurisdictional Area: 

OHWM width ___10 ft.

D-1-100 Ephemeral Drainage (with ID number

and )

PreferredSEGMENT 5Alt B

PreferredSEGMENT 6Alt B

PreviousSEGMENT 6CCentral A and B

Map Sheet Location

C278

C253

C263

C262

C261

C260

C259

RecentSEGMENT 6B

Map Dated: January 28, 2011

(Corps field review 2-2011)

F-I.5-219
D-38-40 D-38-6 D-38-7

D-38-60

 ____1 ft.

0 200 400 600 800 1,000 Feet

Aerial Photography Dated 2008

HBGHuffman-Broadway Group, Inc. · 828 Mission Avenue · San Rafael, California · Phone (415) 925-2000 · Fax (415) 925-2006

Exhibit C. Areas Potentially Subject to Corps Jurisdiction Under Section 404 of the Clean Water Act, DesertXpress Project, HUC 8 Las Vegas Wash Watershed, Clark County, Nevada, Current Preferred Segments 6 Alt B and 6 Alt C, Map Sheet C262

Legend

Jurisdictional Delineation Study Area

Potential Corps Jurisdictional Area: 

OHWM width ___10 ft.

D-1-100 Ephemeral Drainage (with ID number

and )

PreferredSEGMENT 5Alt B

PreferredSEGMENT 6Alt B

PreviousSEGMENT 6CCentral A and B

Map Sheet Location

C278

C253

C264

C263

C262

C261

C260

RecentSEGMENT 6B

Map Dated: January 28, 2011

(Corps field review 2-2011)

F-I.5-220
0 200 400 600 800 1,000 Feet

Aerial Photography Dated 2008

HBGHuffman-Broadway Group, Inc. · 828 Mission Avenue · San Rafael, California · Phone (415) 925-2000 · Fax (415) 925-2006

Exhibit C. Areas Potentially Subject to Corps Jurisdiction Under Section 404 of the Clean Water Act, DesertXpress Project, HUC 8 Las Vegas Wash Watershed, Clark County, Nevada, Current Preferred Segments 6 Alt B and 6 Alt C, Map Sheet C263

Legend

Jurisdictional Delineation Study Area

Potential Corps Jurisdictional Area: 

OHWM width ___10 ft.

D-1-100 Ephemeral Drainage (with ID number

and )

PreferredSEGMENT 5Alt B

PreferredSEGMENT 6Alt B

PreviousSEGMENT 6CCentral A and B

Map Sheet Location

C278

C253

C264

C263

C262

C261

C265

RecentSEGMENT 6B

Map Dated: January 28, 2011

(Corps field review 2-2011)

F-I.5-221
D-38-55

D-38-84

D-38-83 D-38-82

D-38-85

D-38-53

D-38-10

D-38-49

D-38-50

D-38-51 D-38-12 D-38-11

D-38-37 D-38-15 D-38-14

 ____3 ft. ____30 ft.

 ____2 ft.

 ____3 ft.

 ____3 ft.

 ____3 ft.

 ____3 ft.

 ____3 ft.

 ____3 ft.

3 ft. ____

 ____3 ft.

 ____3 ft.

0 200 400 600 800 1,000 Feet

Aerial Photography Dated 2008

HBGHuffman-Broadway Group, Inc. · 828 Mission Avenue · San Rafael, California · Phone (415) 925-2000 · Fax (415) 925-2006

Exhibit C. Areas Potentially Subject to Corps Jurisdiction Under Section 404 of the Clean Water Act, DesertXpress Project, HUC 8 Las Vegas Wash Watershed, Clark County, Nevada, Current Preferred Segments 6 Alt B and 6 Alt C, Map Sheet C264

Legend

Jurisdictional Delineation Study Area

Potential Corps Jurisdictional Area: 

OHWM width ___10 ft.

D-1-100 Ephemeral Drainage (with ID number

and )

PreferredSEGMENT 5Alt B

PreferredSEGMENT 6Alt B

PreviousSEGMENT 6CCentral A and B

Map Sheet Location

C278

C253

C264

C263

C265

C266

C262

RecentSEGMENT 6B

Map Dated: January 28, 2011

(Corps field review 2-2011)

F-I.5-222
W Silverado Ranch Blvd

W Silverado Ranch Blvd

D-38-20 ____

6 ft.

0 200 400 600 800 1,000 Feet

Aerial Photography Dated 2008

HBGHuffman-Broadway Group, Inc. · 828 Mission Avenue · San Rafael, California · Phone (415) 925-2000 · Fax (415) 925-2006

Exhibit C. Areas Potentially Subject to Corps Jurisdiction Under Section 404 of the Clean Water Act, DesertXpress Project, HUC 8 Las Vegas Wash Watershed, Clark County, Nevada, Current Preferred Segments 6 Alt B and 6 Alt C, Map Sheet C265

Legend

Jurisdictional Delineation Study Area

Potential Corps Jurisdictional Area: 

OHWM width ___10 ft.

D-1-100 Ephemeral Drainage (with ID number

and )

PreferredSEGMENT 5Alt B

PreferredSEGMENT 6Alt B

PreviousSEGMENT 6CCentral A and B

Map Sheet Location

C278

C253

C264

C266

C265

C267

C263

RecentSEGMENT 6B

Map Dated: January 28, 2011

(Corps field review 2-2011)

F-I.5-223
W Silverado Ranch Blvd

W Silverado Ranch Blvd

D-38-72

D-38-74

D-38-21 D-38-73

3 ft. ____ ____3 ft. ____3 ft.

0 200 400 600 800 1,000 Feet

Aerial Photography Dated 2008

HBGHuffman-Broadway Group, Inc. · 828 Mission Avenue · San Rafael, California · Phone (415) 925-2000 · Fax (415) 925-2006

Exhibit C. Areas Potentially Subject to Corps Jurisdiction Under Section 404 of the Clean Water Act, DesertXpress Project, HUC 8 Las Vegas Wash Watershed, Clark County, Nevada, Current Preferred Segments 6 Alt B and 6 Alt C, Map Sheet C266

Legend

Jurisdictional Delineation Study Area

Potential Corps Jurisdictional Area: 

OHWM width ___10 ft.

D-1-100 Ephemeral Drainage (with ID number

and )

PreferredSEGMENT 5Alt B

PreferredSEGMENT 6Alt B

PreviousSEGMENT 6CCentral A and B

Map Sheet Location

C278

C253

C266

C265

C268

C267

C264

RecentSEGMENT 6B

Map Dated: January 28, 2011

(Corps field review 2-2011)

F-I.5-224
D-38-74 D-38-34 D-39-40 D-39-24

D-39-23 D-38-33

D-38-45

D-38-30

D-38-25 D-38-80 D-38-78 D-38-79 D-38-81 D-38-75 D-38-32 D-38-70

D-38-76 D-38-71 D-38-77D-38-31

3 ft. ____

 ____1 ft.

 ____

5 ft. ____

1 ft.

 ____3 ft.

3 ft. ____

3 ft. ____

3 ft. ____

0 200 400 600 800 1,000 Feet

Aerial Photography Dated 2008

HBGHuffman-Broadway Group, Inc. · 828 Mission Avenue · San Rafael, California · Phone (415) 925-2000 · Fax (415) 925-2006

Exhibit C. Areas Potentially Subject to Corps Jurisdiction Under Section 404 of the Clean Water Act, DesertXpress Project, HUC 8 Las Vegas Wash Watershed, Clark County, Nevada, Current Preferred Segments 6 Alt B and 6 Alt C, Map Sheet C267

Legend

Jurisdictional Delineation Study Area

Potential Corps Jurisdictional Area: 

OHWM width ___10 ft.

D-1-100 Ephemeral Drainage (with ID number

and )

PreferredSEGMENT 5Alt B

PreferredSEGMENT 6Alt B

PreviousSEGMENT 6CCentral A and B

Map Sheet Location

C278

C253

C266

C267

C268

C265

C269

RecentSEGMENT 6B

Map Dated: January 28, 2011

(Corps field review 2-2011)

F-I.5-225
D-39-40

D-39-49

D-39-43

D-39-46 D-39-47

D-39-50

D-39-48

D-39-3

D-39-45 D-39-44

D-39-42 D-39-30

3 ft. ____

 ____

1 ft.

 ____1.5 ft.

 ____

6 ft.

 ____3 ft.

 ____

1 ft. ____

1 ft.

 ____1 ft.

 ____3 ft.

 ____1 ft.

0 200 400 600 800 1,000 Feet

Aerial Photography Dated 2008

HBGHuffman-Broadway Group, Inc. · 828 Mission Avenue · San Rafael, California · Phone (415) 925-2000 · Fax (415) 925-2006

Exhibit C. Areas Potentially Subject to Corps Jurisdiction Under Section 404 of the Clean Water Act, DesertXpress Project, HUC 8 Las Vegas Wash Watershed, Clark County, Nevada, Current Preferred Segments 6 Alt B and 6 Alt C, Map Sheet C268

Legend

Jurisdictional Delineation Study Area

Potential Corps Jurisdictional Area: 

OHWM width ___10 ft.

D-1-100 Ephemeral Drainage (with ID number

and )

PreferredSEGMENT 5Alt B

PreferredSEGMENT 6Alt B

PreviousSEGMENT 6CCentral A and B

Map Sheet Location

C278

C253

C267

C268

C269

C266

C270

RecentSEGMENT 6B

Map Dated: January 28, 2011

(Corps field review 2-2011)

F-I.5-226
Blue Diamond Rd

D-39-40

D-39-50

D-39-3

D-39-26

D-39-5

D-39-49

D-39-4

D-39-21

3 ft. ____

 ____

6 ft.

 ____

1 ft.

3 ft. ____

 ____3 ft.

 ____

3 ft.

0 200 400 600 800 1,000 Feet

Aerial Photography Dated 2008

HBGHuffman-Broadway Group, Inc. · 828 Mission Avenue · San Rafael, California · Phone (415) 925-2000 · Fax (415) 925-2006

Exhibit C. Areas Potentially Subject to Corps Jurisdiction Under Section 404 of the Clean Water Act, DesertXpress Project, HUC 8 Las Vegas Wash Watershed, Clark County, Nevada, Current Preferred Segments 6 Alt B and 6 Alt C, Map Sheet C269

Legend

Jurisdictional Delineation Study Area

Potential Corps Jurisdictional Area: 

OHWM width ___10 ft.

D-1-100 Ephemeral Drainage (with ID number

and )

PreferredSEGMENT 5Alt B

PreferredSEGMENT 6Alt B

PreviousSEGMENT 6CCentral A and B

Map Sheet Location

C278

C253

C270

C268

C269

C267

C271

RecentSEGMENT 6B

Map Dated: January 28, 2011

(Corps field review 2-2011)

F-I.5-227
D-39-32

D-39-17

D-39-25

D-39-7

 ____0.2 ft.

3 ft. ____

 ____6 ft.

 ____3 ft.

0 200 400 600 800 1,000 Feet

Aerial Photography Dated 2008

HBGHuffman-Broadway Group, Inc. · 828 Mission Avenue · San Rafael, California · Phone (415) 925-2000 · Fax (415) 925-2006

Exhibit C. Areas Potentially Subject to Corps Jurisdiction Under Section 404 of the Clean Water Act, DesertXpress Project, HUC 8 Las Vegas Wash Watershed, Clark County, Nevada, Current Preferred Segments 6 Alt B and 6 Alt C, Map Sheet C270

Legend

Jurisdictional Delineation Study Area

Potential Corps Jurisdictional Area: 

OHWM width ___10 ft.

D-1-100 Ephemeral Drainage (with ID number

and )

PreferredSEGMENT 5Alt B

PreferredSEGMENT 6Alt B

PreviousSEGMENT 6CCentral A and B

Map Sheet Location

C278

C253

C271

C270

C269

C268

C272

RecentSEGMENT 6B

Map Dated: January 28, 2011

(Corps field review 2-2011)

F-I.5-228
West Warm Springs Rd

D-39-17

D-39-12

D-39-8

D-39-25

D-39-13

D-39-11

D-39-10

D-39-16

 ____3 ft.

 ____6 ft.

 ____6 ft.

3 ft. ____

0 200 400 600 800 1,000 Feet

Aerial Photography Dated 2008

HBGHuffman-Broadway Group, Inc. · 828 Mission Avenue · San Rafael, California · Phone (415) 925-2000 · Fax (415) 925-2006

Exhibit C. Areas Potentially Subject to Corps Jurisdiction Under Section 404 of the Clean Water Act, DesertXpress Project, HUC 8 Las Vegas Wash Watershed, Clark County, Nevada, Current Preferred Segments 6 Alt B and 6 Alt C, Map Sheet C271

Legend

Jurisdictional Delineation Study Area

Potential Corps Jurisdictional Area: 

OHWM width ___10 ft.

D-1-100 Ephemeral Drainage (with ID number

and )

PreferredSEGMENT 5Alt B

PreferredSEGMENT 6Alt B

PreviousSEGMENT 6CCentral A and B

Map Sheet Location

C278

C253

C271

C270

C273

C272

C269

RecentSEGMENT 6B

Map Dated: January 28, 2011

(Corps field review 2-2011)

F-I.5-229
Bruce Woodbury Beltway Dean Martin Dr

D-39-13

D-40-24

D-40-14

6 ft. ____

3 ft. ____ ____6 ft.

3 ft. ____

0 200 400 600 800 1,000 Feet

Aerial Photography Dated 2008

HBGHuffman-Broadway Group, Inc. · 828 Mission Avenue · San Rafael, California · Phone (415) 925-2000 · Fax (415) 925-2006

Exhibit C. Areas Potentially Subject to Corps Jurisdiction Under Section 404 of the Clean Water Act, DesertXpress Project, HUC 8 Las Vegas Wash Watershed, Clark County, Nevada, Current Preferred Segments 6 Alt B and 6 Alt C, Map Sheet C272

Legend

Jurisdictional Delineation Study Area

Potential Corps Jurisdictional Area: 

OHWM width ___10 ft.

D-1-100 Ephemeral Drainage (with ID number

and )

PreferredSEGMENT 5Alt B

PreferredSEGMENT 6Alt B

PreviousSEGMENT 6CCentral A and B

Map Sheet Location

C278

C253

C271

C273

C272

C270

C274

RecentSEGMENT 6B

Map Dated: January 28, 2011

(Corps field review 2-2011)

F-I.5-230
Dean Martin Dr

D-40-23

D-40-10

D-40-13

3 ft. ____

3 ft. ____

0 200 400 600 800 1,000 Feet

Aerial Photography Dated 2008

HBGHuffman-Broadway Group, Inc. · 828 Mission Avenue · San Rafael, California · Phone (415) 925-2000 · Fax (415) 925-2006

Exhibit C. Areas Potentially Subject to Corps Jurisdiction Under Section 404 of the Clean Water Act, DesertXpress Project, HUC 8 Las Vegas Wash Watershed, Clark County, Nevada, Current Preferred Segments 6 Alt B and 6 Alt C, Map Sheet C273

Legend

Jurisdictional Delineation Study Area

Potential Corps Jurisdictional Area: 

OHWM width ___10 ft.

D-1-100 Ephemeral Drainage (with ID number

and )

PreferredSEGMENT 5Alt B

PreferredSEGMENT 6Alt B

PreviousSEGMENT 6CCentral A and B

Map Sheet Location

C278

C253

C274

C273

C272

C271

C275

RecentSEGMENT 6B

Map Dated: January 28, 2011

(Corps field review 2-2011)

F-I.5-231
Dean Martin Dr W Russell Rd

D-40-19

D-40-11

D-40-1

D-40-17

D-40-12

D-40-15

 ____

3 ft.

 ____

3 ft.

 ____3 ft.

0 200 400 600 800 1,000 Feet

Aerial Photography Dated 2008

HBGHuffman-Broadway Group, Inc. · 828 Mission Avenue · San Rafael, California · Phone (415) 925-2000 · Fax (415) 925-2006

Exhibit C. Areas Potentially Subject to Corps Jurisdiction Under Section 404 of the Clean Water Act, DesertXpress Project, HUC 8 Las Vegas Wash Watershed, Clark County, Nevada, Current Preferred Segments 6 Alt B and 6 Alt C, Map Sheet C274

Legend

Jurisdictional Delineation Study Area

Potential Corps Jurisdictional Area: 

OHWM width ___10 ft.

D-1-100 Ephemeral Drainage (with ID number

and )

PreferredSEGMENT 5Alt B

PreferredSEGMENT 6Alt B

PreviousSEGMENT 6CCentral A and B

Map Sheet Location

C278

C253

C275

C274

C273

C272

C276

RecentSEGMENT 6B

Map Dated: January 28, 2011

(Corps field review 2-2011)

F-I.5-232
Dean Martin Dr

W Hacienda Ave

D-40-2

D-40-17

D-40-19

D-40-21

D-40-7 D-40-22 D-40-6

D-40-8

3 ft. ____

 ____

12 ft.

 ____

3 ft.

 ____

3 ft.

 ____

3 ft.

 ____3 ft.

0 200 400 600 800 1,000 Feet

Aerial Photography Dated 2008

HBGHuffman-Broadway Group, Inc. · 828 Mission Avenue · San Rafael, California · Phone (415) 925-2000 · Fax (415) 925-2006

Exhibit C. Areas Potentially Subject to Corps Jurisdiction Under Section 404 of the Clean Water Act, DesertXpress Project, HUC 8 Las Vegas Wash Watershed, Clark County, Nevada, Current Preferred Segments 6 Alt B and 6 Alt C, Map Sheet C275

Legend

Jurisdictional Delineation Study Area

Potential Corps Jurisdictional Area: 

OHWM width ___10 ft.

D-1-100 Ephemeral Drainage (with ID number

and )

PreferredSEGMENT 5Alt B

PreferredSEGMENT 6Alt B

PreviousSEGMENT 6CCentral A and B

Map Sheet Location

C278

C253

C275

C274

C276

C277

C273

RecentSEGMENT 6B

Map Dated: January 28, 2011

(Corps field review 2-2011)

F-I.5-233
W Tropicana Ave

D-40-2 D-40-3 D-40-16

3 ft. ____

0 200 400 600 800 1,000 Feet

Aerial Photography Dated 2008

HBGHuffman-Broadway Group, Inc. · 828 Mission Avenue · San Rafael, California · Phone (415) 925-2000 · Fax (415) 925-2006

Exhibit C. Areas Potentially Subject to Corps Jurisdiction Under Section 404 of the Clean Water Act, DesertXpress Project, HUC 8 Las Vegas Wash Watershed, Clark County, Nevada, Current Preferred Segments 6 Alt B and 6 Alt C, Map Sheet C276

Legend

Jurisdictional Delineation Study Area

Potential Corps Jurisdictional Area: 

OHWM width ___10 ft.

D-1-100 Ephemeral Drainage (with ID number

and )

PreferredSEGMENT 5Alt B

PreferredSEGMENT 6Alt B

PreviousSEGMENT 6CCentral A and B

Map Sheet Location

C278

C253

C276

C275

C277

C278

C274

RecentSEGMENT 6B

Map Dated: January 28, 2011

(Corps field review 2-2011)

F-I.5-234
D-40-16

 ____3 ft.

 ____3 ft.

0 200 400 600 800 1,000 Feet

Aerial Photography Dated 2008

HBGHuffman-Broadway Group, Inc. · 828 Mission Avenue · San Rafael, California · Phone (415) 925-2000 · Fax (415) 925-2006

Exhibit C. Areas Potentially Subject to Corps Jurisdiction Under Section 404 of the Clean Water Act, DesertXpress Project, HUC 8 Las Vegas Wash Watershed, Clark County, Nevada, Current Preferred Segments 6 Alt B and 6 Alt C, Map Sheet C277

Legend

Jurisdictional Delineation Study Area

Potential Corps Jurisdictional Area: 

OHWM width ___10 ft.

D-1-100 Ephemeral Drainage (with ID number

and )

PreferredSEGMENT 5Alt B

PreferredSEGMENT 6Alt B

PreviousSEGMENT 6CCentral A and B

Map Sheet Location

C278

C253

C276

C278

C277

C275

RecentSEGMENT 6B

Map Dated: January 28, 2011

(Corps field review 2-2011)

F-I.5-235
W Flamingo Rd

0 200 400 600 800 1,000 Feet

Aerial Photography Dated 2008

HBGHuffman-Broadway Group, Inc. · 828 Mission Avenue · San Rafael, California · Phone (415) 925-2000 · Fax (415) 925-2006

Exhibit C. Areas Potentially Subject to Corps Jurisdiction Under Section 404 of the Clean Water Act, DesertXpress Project, HUC 8 Las Vegas Wash Watershed, Clark County, Nevada, Current Preferred Segments 6 Alt B and 6 Alt C, Map Sheet C278

Legend

Jurisdictional Delineation Study Area

Potential Corps Jurisdictional Area: 

OHWM width ___10 ft.

D-1-100 Ephemeral Drainage (with ID number

and )

PreferredSEGMENT 5Alt B

PreferredSEGMENT 6Alt B

PreviousSEGMENT 6CCentral A and B

Map Sheet Location

C278

C253

C278

C277

C276

RecentSEGMENT 6B

Map Dated: January 28, 2011

(Corps field review 2-2011)

F-I.5-236