REC-OCE-7021

J. M. Lara

Office of Chief Engineer

and

J. I. Sanders

Region 3

Bureau of Reclamation

August 1970
BM-230 (6-70)

Bure,uo(Reclatnation TECHNICAL REPORT STANDARD TITLE PAGE

_

I. REPORT NO. [. GoVERp4NeNtACCesstONo. .- CIPIENT'SCATALOGNO.

REC-OCE--70-21 I ____________________________

4. TITLE AND SUBTITLE S. REPORT DATE

The 1963-64 Lake Head Survey Aug 70

6. PERFORMING ORGANIZATION CODE

Code

7. AUTHOR(S) 8. PERFORMING ORGANIZATION

REPORT NO.

J. M. Lara and J. I. Sanders REC-OCE-7o-21

9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. WORK UNIT NO.

Division of Project Investigations

Office of Chief Engineer Region 3 Office ii. CONTRACT OR GRANT NO.

Bureau of Reclamation Bureau of Reclanatlo

Denver, Colorado 80225 Boulder City, Nevad 13. TYPE OF REPORT AND PERIOD 8J00 COVERED

12. SPONSORING AGENCY NAME AND ADDRESS

14. SPONSORING AGENCY CODE

15. SUPPLEMENTARY NOTES

IS. ABSTRACT

The 1963-64 Lake Head survey was run to compute the reservoir capacity.

Results of the geodetic and hydrographic surveys and sediment sampling

equipment are described. The geodetic survey showed Hoover Dam subsided an

average of 118 mm since 1935. Sonic sounding, photogrammetry, and crosssectional profiling methods were used to run the hydrographic survey.

Reservoir area and capacity tables were generated using an electronic

computer. The present lake capacity is 29,755,000 acre-ft and the reservoir

surface area is 162,700 acres at elevation 1229 ft. 2,720,000 acre-ft of

sediments accumulated in the lake since 1935. A unit weight of 60 lb/cu ft

was determined representative of the deposited sediments. Samples were

collected from the major basins with a piston core sampler. A gamma probe

was used to measure in situ wet bulk densities. Special sampling with a

drill rig was conducted in Pierce Basin representing the sediment accumulation in the delta area. The reservoir trap efficiency is judged to be 100%.

17. KEY WORDS AND DOCUMENT ANALYSIS

DESCRIPTORS-- / *reservoir surveys! *reservoir silting/ aggradation/ core

drilling! *geodetic surveys! first order surveys! land subsidence! *gmpjna

rays! rebound! *hydrographic surveys! sounding! photogrammetry! thaiweg!

topographic mapping! *sedimentation! fluvial hydraulics! unit weight!

sediment transportl sediment sampling! *physicai. properties! watersheds

ba1i)/ ay efficiency

IE

- / reservoir capacity! gamma probes! Arizona-Nevada! Lake Mead

c. COSAT! Fie(d/Group6F

IS. DISTRIBUTION STATEMENT 19. SECURITY CLASS

(THIS REPORT)

, NO. )F PAGEI'

Available from the National Technical Information UNCLASSIFIED

162

Service, Operations Division, Springfield, 20. CLASS 22. PRJCE

Virginia 22151. UNCLASSIFIED $3.00
REC-OCE-70-21

THE 1963-64 LAKE MEAD STUDY

by

J. M. Lara

J. I. Sanders

August 1970

Division of Project Investigations

Office of Chief Engineer

Denver, Colorado

and

Division of Water and Land Operations

Region 3 Office

Boulder City Nevada

UNITED STATES DEPARTMENT OF THE INTERIOR BUREAU OF RECLAMATION

Ellis L. Armstrong

Commissioner
CONTENTS

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Page

Part 1

Foreword 1

Acknowledgments 3

Part 2

Geodetic Survey 5

Objective 5

Field Procedure 5

Precise Reteveling 5

Adjustment of Levels 5

Interpretation of Releveling Results 5

Review of Structural Geology 5

Analysis of Releveling Data 33

Effect of Subsidence or Rebound upon Reservoir Capacity 36

Part 3

Hydrographic Survey 37

Objective 37

Vertical Control 37

Horizontal Control 37

Triangulation Work 37

Hydrographic Survey Procedures 44

Lake Mead Area West of Longitude 113° 57' 44

Lower Granite Gorge Area 47

Determination of Contour Areas 49

Computation of Reservoir Capacities 50

Miscellaneous Hydrologic Data 50

Part 4

Investigations of Sediment Properties 75

Methods of Field Investigation 75

Drive Sampling 75

Piston Core Sampling 90

Bottle Sampling 95

Gamma Probing 95
CONTENTS-Continued

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Analyses of Sediment Properties 101

Physical Properties 101

Moisture Content 103

Specific Gravity 103

Plasticity 115

Particle-size Gradation 115

Mineralogical Properties 120

Chemical Properties 120

Interpretation of Sediment Properties 121

Part 5

Quantitative Sedimentation Analyses 141

Sediment Accumulations 141

Measured Reservoir Sediment Volumes 157

Measured and Estimated Sediment Inflow 157

Trap Efficiency 166

Representative Particle Gradation 166

Unit Weight Analyses 166

Sedimentation Data Summary 166

Part 6

Summary and Conclusions 171

LIST OF TABLES

No. Title

2-1 Hoover Dam Level Net Elevations and Changes in Elevation 9

2-2 Average Subsidence in Millimeters 36

3-1 Horizontal Control Stations Used for Aerial Photography 43

3-2 1963-64 Lake Mead Sheets 45

3-3 1935 Lake Mead Contour Areas 52

3-4 Comparative Area Data 64

3-5 Lake Mead Surface Areas from 1963-64 Survey 66

3-6 Lake Mead Capacity-Listed by Basins 1963-64 Survey Data 67

3-7 Lake Mead Capacities-Listed by Basins 1935, 1947-48,

1963-64 Surveys 69

4-1 Summary of Sediment Test Data 105

4-2 Estimated Mineralogical Composition of Sediments 120

4-3 Chemical Composition of Sediments 122

4-4 Clay Mineral Versus Physical Properties 139

5-1 Sediment Volumes by Basins Accumulated Between

1948-49 and 1963-64 159

5-2 Total Sediment Volumes Accumulated in Each Basin Since 1935 160

5-3 Reservoir Sediment Data Summary 167
CONTENTS-Continued

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LIST OF FIGURES

No. Title Page

1-1 Colorado River Basin 2

2-1 Hoover Dam area level net 7

2-2 Geodetic Survey-Contours showing changes in elevation,

1935to 1963 34

2-3 Geodetic Survey-Contours showing changes in elevation,

1949to1963 35

31 Lake Mead Basin location map 39

3-2 Map showing tidal and staff gages location 41

3-3 Map of control points for aerial photography 42

34 Reservoir sheet index map 46

3-5 Amphibian plane to transport survey personnel 48

3-6 Stadia to establish reservoir water's edge 49

3-7 Lake Mead area and capacity curves 71

3-8 Graph of monthly evaporation losses and month end

surface areas 72

39 Graph of average monthly Hoover Dam releases and

available contents 73

4-1 Sediment sample location map 77

4-2 Pierce Basin photographs 79

4-3 Pierce Basin drilling site photographs 80

4-4 Photographs-Helicopter carrying equipment 81

4-5 Barges used in sediment investigations 82

4-6 Stern view of barges used in sediment investigations and

view of sea mules used to propel barges 83

4-7 Schematic sketch of deck layout on barge 85

4-8 Drill rig setup at Pierce Basin 87

4-9 Drive sampler 88

4-10 Doubletubesampler 89

4-1 1 Schematic sketch of piston core sampler 91

4-12 Photographs of piston core sampler 92

4-13 A-frame used to hoist piston core sampler 93

4-14 Schematic sketch of piston core sampler operation 94

4-15 Retrieval of piston core sampler 96

4-16 Preparing sediment core sample for shipment 97

4-17 Modified Foerst sampler 98

4-18 Gamma probe 99

4-19 Ratemeter and retriever 100

4-20 Gamma probe operation 102

4-21 Field density equipment 104

4-22 Piston core samples packed in dry ice to be frozen 111

4-23 Cutting and weighing piston core samples 112

4-24 Extruding piston core sample that is thoroughly mixed to

pick up any free moisture 113

4-25 Piston core sample separated for specified tests. Measuring

plastic liners for volume determinations 114

4-26 Specific gravity determinations 116

4-27 Apparatus to run Atterberg tests 117

4-28 Hydrometer tests 119

4-29 Drill Hole No. 1 physical properties 124

4-30 Physical properties of sediment samples collected

at various locations 125
CONTENTS-Continued

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No. Title Page

4-31 View of the Colorado River in the Pierce Basin area 128

4-32 Comparison of dry unit weights 130

4-33 Clay mineral related to plasticity index, particle size

gradation, and median diameter 138

5-1 Location map of sediment cross sections 142

5-2 Cross-sectional profiles 143

5-3 Longitudinal profiles-Colorado River 155

5-4 Virgin River profiles 158

5-5 Graph of suspended sediment load-Colorado River near

Grand Canyon 161

5-6 Graph of monthly discharge-Colorado River near Grand Canyon 163

iv

PART 1-FOREWORD

Lake Mead is a reservoir that was formed by the

construction of Hoover Dam in 1935. The dam is

located 30 miles east of Las Vegas, Nevada, in Black

Canyon of the Colorado River. The original capacity of

Lake Mead was 32,471,000 acre-feet at elevation 1229

feet. The 1948-49 survey of Lake Mead was prompted

by the need to know the reduction in capacity because

of sediment accumulation. In 1963, Glen Canyon Dam

on the Colorado River, 370 miles upstream from

Hoover Dam, was closed. The 1963-64 survey of Lake

Mead was made to update the capacity of the reservoir

at the time of the closure of Glen Canyon Dam.

Results of the 1963-64 survey are analyzed in this

report to investigate environmental factors and to

study the sedimentation features. The geodetic and

hydrographic surveys are described. A discussion is

included on the physical characteristics of the

deposited reservoir sediments and on the instruments

and field techniques used.

Graphs, maps, tables, and photographs are extensively

used to document the information and analyses made

of the field measurements and field data collected

during the survey.

Standard land surveying methods combined with the

photogrammetric and special hydrographic surveys

were used to map the reservoir topography.

Lake level areas delineated at 10-foot vertical intervals

from the topography were planimetered and used to

compute the reservoir capacity. First order levels were

rerun over an established geodetic base network

totaling 340 miles. Funds were not available for field

crews to complete all the original network lines.

Special instruments and apparatus were used to sample

or obtain physical samples of the sediments deposited

at various locations in the reservoir. Drilling equipment

was needed for a special test site located in the delta

area of Pierce Basin. Personnel and equipment had to

be transported by helicopter to this test site.

The Colorado River Basin and the location of Hoover

Dam and Lake Mead are shown on the map in Figure

1-1. The renown of Hoover Dam was highlighted in

1955 when it was selected as one of the seven

engineering wonders in the United States by the

American Society of Civil Engineers.11 The Lake

Mead area was originally mapped in 1935 by the Soil

Conservation Service before the dam was completed.

Topographic maps of the area were prepared with a

1:12,000 scale for each 5-minute quadrangle of

latitude and longitude (Figure 3-1).

When Hoover Dam was closed in 1936, about

3,223,000 acre-feet of dead storage was available in the

space below elevation 895 feet. Although the U.S.

Geological Survey had measured the suspended

sediment loads ot the Colorado River near Grand

Canyon above Lake Mead since 1926, the actual

amount of the sediment accumulation in the lake was

unknown. The quantity and distribution of these

sediments became a major concern related to the

reservoir operation and storage loss; consequently, a

project was organized after the second world war to

resurvey the lake to determine the reservoir capacity at

that time. The 1948-49 sediment survey resulted from

these efforts and two reports on Lake Mead,

comprehensively describing the lake and its environs,

were published to document this survey. The first was

issued in three volumes12 and the other was published

as a single report13.

Subsequent to the 1948-49 survey, Bureau of

Reclamation engineers concluded that Lake Mead

should be resurveyed to coincide, in time,

approximately with the closure of Glen Canyon Dam

located about 370 miles above Hoover Dam. A

comparison could then be made of the rate,

composition, and location of sediment accumulations

in Lake Mead before and after the Glen Canyon Dam

closure. After considering several proposals from

hydrographic firms, a cooperative agreement was

reached in June 1963, between the Departments of the

Interior and Commerce to have the Coast and Geodetic

Survey run the survey of Lake Mead. Requirements of

the survey were established in the agreement which

included that it would be run similar to the one in

1948-49. The main requirement was to obtain

sufficiently detailed and accurate data for the reservoir

below elevation 1229 feet, from which computations

of the current lake area and capacity could be made at

10-foot vertical intervals throughout its depth. The

1963-64 survey was run to accomplish this purpose.

Finch, J. Kip, "Seven Modern Civil Engineering Wonders in U.S. Named," C/v//Engineering, Vol. 25, No. 11, pp

33-45, Nov. 1955.

'2US Department of the Interior, "Lake Mead Comprehensive Survey of 1948-49," Report. Vols. I, II, and Ill,

Feb. 1954.

13Geological Survey, "Comprehensive Survey of Sedimentation in Lake Mead, 1948-49," Professional Paper 295,

254 p,1960.
Map No. 57-3OO536 COLORADO RIVER BASIN

(Location of Lake Mead)

2

SCALE OF UtLES

JANUASY IOU

DEPARTMENT OF THE INTERIOR

BUREAU OF RECLAMATION

(Regions 3 and Ellis L. Armstrong, Commissioner

FIGURE 1-1
ACKNOWLEDGEMENTS

Arrangements for the survey and coordination with the

Office of Chief Engineer, Denver, Colorado, were made

by John S. McEwan, Chief, Channel Control Branch

under the supervision of Paul A. Oliver, River Control

Engineer, Lower Colorado River Control Office,

Boulder City, Nevada.

Preparation of this report was under the joint

supervision of Joe M. Lara, Hydraulic Engineer,

Division of Project Investigations, Office of Chief

Engineer, Denver, Colorado, and John I. Sanders,

Supervisory Hydraulic Engineer, Water Scheduling

Branch, Division of Water and Land Operations,

Boulder City, Nevada, under the supervision of B. P.

Beliport, Chief Engineer, and A. B. West, Regional

Director.

Mr. Alan C. Doyle, Geologist, Water Scheduling

Branch, Division of Water and Land Operations,

Boulder City, Nevada, prepared the portion of the

report on "Analysis of Releveling Data" and gave

detailed assistance on all portions of the report

prepared by the Boulder City, Nevada Office.

Mr. Dale P. Weskamp, Geologist, Geology Branch,

Division of Project Development, Boulder City,

Nevada, wrote the section on "Review of Structural

Geology" and made helpful suggestions on other

portions of the report concerning geology.

Personnel of the U.S. Coast and Geodetic Survey ran

the hydrographic survey. The Chiefs of Party were:

Mr. Clarence Symns, Chief, Geodetic Level Party

Mr. P. A. Stark, Comdr., and Mr. H. E. McCall, Lt.,

Chiefs, Hydrographic Field Party 219

Mr. James H. Blumer, Lt., Chief, Photographic Party

6423

Parts of the "Descriptive Reports" (mentioned on page

44) prepared by the field parties of the U.S. Coast and

Geodetic Survey were quoted verbatim in the report

because it was not practical to contact personnel who

prepared the original reports for more detailed

descriptions.

Mrs. Hortense G. Bagni, Engineering Technician, under

the supervision of C. 0. Wamstad, Chief, Design

Branch, Boulder City, Nevada, was responsible for the

detailed planimetering of the reservoir sheets, provided

by the U.S. Coast and Geodetic Survey and the Soil

Conservation Service 5-minute quadrangle sheets

requiring planimetric work.

Messrs. Whitney M. Borland and Ernest L. Pemberton,

Chief and Assistant Chief, Sedimentation Branch,

respectively, Office of Chief Engineer reviewed this

report in great depth. Both offered helpful advice and

suggestions in preparing it for final publication.

Mr. Thomas D. Murphy, Hydraulic Engineer, formerly

of Division of Project Investigations, Office of Chief

Engineer, Denver, Colorado, was responsible for the

collection of the sediment samples. He was also

responsible for drafting a preliminary outline guide and

partial writeup of the report.

Personnel of the various laboratories in the Division of

Research, Office of Chief Engineer, Denver, Colorado,

ran the sediment, mineralogical, and chemical tests of

the collected sediment samples.

Personnel of the Division of Data Processing, Office of

Chief Engineer, Denver, Colorado, ran the

computations and generated the area and capacity

tables using the electronic computer.

Many others of both the Office of Chief Engineer,

Denver, Colorado, and the Regional Office, Boulder

City, Nevada, gave valuable assistance and advice in

completing the survey and during the preparation of

this report.

3

PART 2-GEODETIC SURVEY

Objective

The first geodetic level net for the Lake Mead area was

established in March and April 1935. This level net,

referred to as the Hoover Dam level net, has served as a

reference from which periodic measurements are made

of any vertical movement subsequently occurring in

the immediate and surrounding areas because of the

loading by impounded reservoir waters. Because this

reference was established when the reservoir was

beginning to fill, the elevations of established bench

marks represented the conditions before there was any

appreciable loading by the impounded waters. A

precise level resurvey of the established bench marks

was rerun in the October 1940 through April 1941

period and again between December 1949 and July

1950.

A portion of the Hoover Dam level net was again

resurveyed by the Coast and Geodetic Survey from

April through June 1963. This survey established

vertical control for the 1963-64 Lake Mead survey and

provided information useful in estimating the expected

vertical deformation of the earth's crust believed

caused largely by the varying load brought about by

the change in amount of impounded reservoir waters.

The pattern of the basic level net is shown in Figure

2-1. Table 2-1 lists the elevations in meters for the

respective bench marks obtained during each run of the

level surveys in 1935, 1940-41, 1949-50, and 1963.

Field Procedure

Precise Releveling

In April, May, and June 1963, a Coast and Geodetic

Survey field party ran first-order releveling over all or

portions of the following basic level-net lines shown in

Figure 2-1: (III) Las Vegas to 15 miles south of Las

Vegas, Nevada; (IV) Las Vegas to Corn Springs,

Nevada; (V) Las Vegas to Cane Springs, Nevada; (IX) 4

miles west of Boulder City, Nevada, to 35 miles north

of Chloride, Arizona; and spur line from 4 miles west

of Hoover Dam to Saddle Island, Nevada; (X) Las

Vegas to Searchlight, Nevada; (Xl) 10 miles north of

Las Vegas, Nevada, to 35 miles north of Chloride,

Arizona. Not all of the original basic lines shown in

Figure 2-1 were rerun in 1963 because funds were

curtailed. Bench mark numbers are shown only for

lines which were releveled in 1963.

The level lines rerun in the 1963-64 survey totaled 340

miles. The average adjustment distribution rate was

0.35 mm per kilometer and the maximum on a line of

appreciable size was 0.85 mm per kilometer.

Requirements for the 1963 level net set a maximum

tolerance of 3.0 mm ',/ibetween the forward and

backward runs, the same as set for previous level nets.

The term, K, is the length of run in kilometers. Table

2-1 shows the millimeter changes in elevations during

the two periods 1935 to 1963, and 1949 to 1963, for

the respective bench marks over which levels were

rerun, and for which a "special" adjustment was made

based on Bench Mark Ri at Cane Springs.

Adjustment of Levels

The basic level network of 1935 was adjusted to sea

level datum of 1929 by holding fixed the elevations

resulting from previous adjustments for a ring of

junctions on the perimeter of the net. This

"supplementary" adjustment was made to obtain

elevations consistent with the surrounding control and

the same elevations were published for general public

use. Similar "supplementary" adjustments were made

for each of the reruns since 1935.

Considering future geodetic studies of the reservoir

area, it was believed advisable to make a "special"

adjustment in which the elevations would be free from

the effects of warping due to fitting to the older net.

Accordingly, a second adjustment was made for each

of these level runs, in which only one bench mark

elevation (Ri at Cane Springs) from the first

adjustment, was held fixed. The elevations resulting

from this "special" adjustment were used as a network

for comparing subsequent basin subsidence and

rebound. The elevations and changes in elevations of

each bench mark listed in Table 2-1 are based on this

"special" adjustment.

Interpretation of

Releveling Results

Review of Structural Geology

A brief review of the structural geology of the Lake

Mead area is desirable for a better understanding of the

vertical earth crustal movements. Lake Mead is located

in southeastern Nevada and northern Arizona, a

portion of the Basin and Range Physiographic

Province. The area surrounding and including the

reservoir is characterized by broad valleys bordered by

north-south trending mountain ranges of rugged relief.

The region is bordered on the east by the Grand Wash

Cliffs; on the north by the Virgin, Muddy, and

Frenchman Mountain ranges; on the west by the Spring

Mountain range; and on the south by the Black,

LINE TITLES

I HACKBERRY TO KINGMAN, ARIZ.

ii NIPTON, CALIF TO KINSMAN, ARIZ,

Iii NIPTON, CALIF. TO LAS VEGAS, NEV.

IV LAS VEGAS TO CORN SPRINGS, NEV

V LAS VEGAS TO CANE SPRINGS, NEV.

Vi MOAPA, NEV, TO BEAVER DAM CREEK, ARIZ,

Vii I-IACKBERRY, ARIZ., TO MOAPA, NEV

Viii 6 ML W. OF PATTERSON'S WELL, ARIZ., TO (0 MI. E. OF ST. THOMAS, NEV.

IX 4 Ml W OF BOULDER CITY, HEy, TO 10 MI. N. OF CHLORIDE, ARIZ,

(INCLUDING BRANCH LINE TO SADDLE ISLAND)

X LAS VEGAS TO SEARCHLIGHT, HEy.

Xi 10 MI. N. OF LAS VEGAS, NEV TO 35 MI. N. OF CHLORIDE, ARIZ.

NOTE -THE BASIC LEVEL NET WAS ESTABLISHED IN 1935 BY PRECISE* LEVELING. IT WAS

RELEVELED IN 940 41 IN 1949-50 5 LARGE PORTON OF THE BASIC NET WAS AGAIN

RE LEVELED. IN 1953 THE NET WAS AGAIN RELEVELED OVER THAT PORTION FOR WHICH

BENCH MARK NUMBERS ARE SHOWN ON THIS MAP, INCLUDING A NEW BRANCH To

SADDLE ISLAND FROM LINE IX

* THE SPECIFICATIONS FOR FIRST -ORDER LEVELING REQUIRE THAT EACH

SECTION MUST BE RUN IN OPPOSITE DIRECTIONS UNTIL A FORWARD AND

A BACKWARD RUNNING AGREE WITHIN THE LIMIT ± 4 0 MM.W (K BEING

THE LENGTH OF THE SECTION IN KM ) ON THE LEVELINGS OF 1935,

THE 1940-41, THE 1946-49, AND 1963-64 REQUIREMENT WAS ± 3.0 MM T)

Table 2-1

HOOVER DAM LEVEL NET ELEVATIONS

AND CHANGES IN ELEVATIONS

Elevations resulting from the Special Adjustments

of the Surveys of 1935, 1940-41, 1949-50, and 1963-64.

Line I: Hackberry to Kingman, Arizona __________

I

j Change in elevation

BM Elevation (meters) (milUn3eter

I 1935 1940-41 1949-50 1963 I 1935-63 1949-63

K 1 1080.1844 1080.0983

148+80 1079.2574 1079.1729

A 124 1081.9889 1081.9035

B 124 1085.4086 1085.3245

C 124 1088.6374 1088.5535

D 124 1095.2701 1095.1885

3608 1099.9290 1099.8494

E 124 1098.1447 1098.0642

F 124 1099.5595 1099.4789

3591 1094.6037 1094.5248

G 124 1090.0121 1089.9342

3542 1079.6903 1079.6140

H 124 1074.7749 1074.6962

J 124 1055.2318 1055.1520

H 1 1042.31 14 1042.2336

K 124 1021 .4238 1021.3491

L 124 1009.8357 1009.7615

M 124 1000.9188 1000.8439

N 124 995.1055 995.0339

P 124 997.7024 997.6309

o 124 999.7564 999.6858

R 124 1003.0579 1002.9930

S 124 1004.6518 1004.5883

T 124 1008.6684 1008.6058

U 124 1017.8350 1017.7720

V 124 1029.0919 1029.0328

W 124 1037.7705 1037.7147

X 124 1050.9463 1050.8849

Y 124 1061.5729 1061.5155

Z 124 1067.3301 1067.2784

Z 126 1048.8751 1048.8263

B 1 1014.8973 1014.8433

Al 1018.1959 1018.1423
Table 2-1 -Continued

Line II: Nipton, California, to Kingman, Arizona

BM

E6

A 328

J 182

A 148

K 110

B 148

L 110

C 148

M 110

D 148

N 110

E 148

P 110

F 148

Q 110

G 148

R 110

H 148

S 110

J 148

T 110

K 148

V 109

W109

L 148

U 110

M 148

V 110

N 148

W 110

Ferry

R.M. 2

R.M. 1

P 148

X 110

Q 148

Y 110

R 148

Z 110

S 148

Elevation (meters

922.0181

981.8800

1039.6527

1111.0309

1180.8758

1258.6884

1308.6676

1376.5210

1422.5215

1492.58 16

1443.8649

1390.6723

1357.1747

1307.1002

1260.7922

1213.0199

1178.5418

1142.7019

1114.8889

1087.5 184

1070.5452

1048.2519

105 1 .44 12

1079.9647

1085.1156

1053.0739

990.6139

926.7303

855.1567

763.0853

736.7976

736.3956

735.9222

690.8752

622.3783

554.3132

482.9640

418.8478

350.8653

300.8739

1940-41

921.9880

981.8511

1039.6303

1111.0114

1180.8643

1258.6842

1308.6670

1376.5209

1422.5265

1492.5880

1443.87 17

1390.6776

1357.18 10

1307. 1052

1260.7867

12 13.0143

1178.5308

1142.6879

1114.87 18

1087.4986

1070.5205

1058.2296

107 1.4217

1079.9457

1085.0996

1053.0571

990.5919

926.7203

855.1423

763.0695

736.7817

736.3813

735.9085

690.8588

622.3573

554.2874

482.9307

418.8113

350.8327

300.8405

921.8840

981.7437

1039.5201

11110.8974

1180.8269

1268.5571

1308.5424

1376.3925

1422.4 150

1492.453 1

1443.7377

1390.5401

1357.0389

1306.9652

1260.6450

1212.883 1

1178.4012

1142.5586

1114.7480

1087.3725

1070.397 1

1058.1077

107 1.3028

1084.9799

1052.9391

990.4806

926.6080

855.0375

762.9772

736.6922

736.2906

735.8173

690.7728

622.2812

554.2226

482.8737

418.7593

350.7802

300.7898

Change in elevation

(millimeters)

10
Table 2-1-Continued

Line II: Nipton, California, to Kingman, Arizona-Continued

Change in elevation

BM _______________

Elevation (meters) (millimeters)

____________ 1935 1940-41 1949-50 _____ 1963 1935-63 1949-63

A lli 265.6824 265.6508 265.6017

1 148 193.3719 193.3343 193.2947

398.1 A 188.5515 188.5135 188.4824

398.1 B 186.6282 186.5868 186.5494

A 116 175.8931 175.8414 175.8051

P 52 175.0226 174.9699 174.9361

B 116 175.4384 175.3839 175.3563

Q 52 182.0895 182.0354 182.0126

C 116 228.5885 228.5354 228.5098

Glow 290.9689 290.9166 290.8914

R 52 293.0490 292.9977 292.9728

D 116 374.2008 374.1481 174.1239

S 52 461.7001 461.6446 461.6206

E 116 563.1241 563.0765 563.0421

1 52 633.3543 633.3069 633.2728

P 53 690.3992 690.3437

U 52 871.1694 871.1038 871.0730

G 116A 925.6027 925.5330 925.4991

G 116 1024.8128 1024.7529 1024.7064

V 52 1161.9087 1161.8415 1161.7943

H 116 1117.0309 1116.9625 1116.9133

W 52 1065.8133 1065.7472 1065.6987

J 116 1023.8798 1023.8118 1023.7622

X 52 990.8453 990.7766 990.7306

K 116 969.9569 969.8895 969.8486

Y 52 941.1790 941.1025 941.0632

L 116 916.5657 916.5004 916.4564

Z 52 903.8929 903.8234 903.7831

M 116 913.1827 913.1192 913.0795

A 60 932.8847 932.8224 932.7794

N 116 974.1947 974.1341 974.0871

C 60 988.0418 987.9738

P 116 1006.4387 1006.3747

D 60 1041.0819 1041.0232

Q 116 1061.7499 1061.6922

E 60 1085.6583

R 116 1100.9290

F 60 1148.6222

S 116 1180.4595

G 60 1205.4144

1085.6009

1100.8710

1148.5685

1180.4017

1205.3583

11
Table 2-1 -Continued

Line II: Nipton, California, to K ingman, Arizona-Continued

Change in elevation

BM L- _____

Elevation (meters) (millimeters)

-______________ 1935 _____ 1940-41 1949-50 1963 1935-63 1949-63

H60 1222.0551 1221.9987

T116 1179.9541 1179.8915

J60 1140.9635 1140.9044

U 116 1108.0690 1108.0035

K60 1089.5409 1089.4730

V 116 1086.2288 1086.1590

L 60 1068.3982 1068.3215

W 116 1052.0556 1051.9830

M 60 1065.8344 1065.7519

X 116 1050.1027 1050.0243

N 60 1032.9147 1032.8371

Y 116 1003.3494 1003.2722

P 60 986.6049 986.5269

Z 116 957.4494 957.3770

Q 60 949.6790 949.6077

X 119 1000.3891 1000.3271

R 60 1055.1837 1055.1151

S 60 1106.1798 1106.1258

Z 119 1054.0523 1053.9949

Line Ill: Nipton, California, To Las Vegas, Nevada

H 328 917.0277 916.9971 916.8957

G 328 904.2849 904.2538 904.1493

F 6 888.7312 888.6975 888.5926

F 328 868.1503 868.1206 868.0160

G 6 854.6171 854.5910 854.4805

E 328 845.5023 845.4817 845.3700

D 328 843.6213 843.6028 843.4896

C 328 846.4611 846.4453 846.3310

B 328 838.6682 838.6474 838.5317

H 6 836.7741 836.7545 836.6406

0 150 832.9007 832.8858 832.7706

P 150 828.2186 828.2002 828.0841

Roach 815.0074 814.9874 814.8695

Roach 798.5678 798.5482 798.4224

A 796.3413 796.3209

N 150 795.1718 795.1533 795.0328

M 150 795.2918 795.2701 795.0636

L 150 795.7124 795.6876 795.5712

K 150 807.9107 807.8874 807.7662

B 823.9988 823.9808 823.8621

12
Table 2-1-Continued

Line Ill: Nipton, California, to Las Vegas, Nevada-Continued

BM Elevation

Change in elevation

(millimeters)

J 150 826.8858 826.8703 826.7500

H 150 835.9910 835.9871 835.8619

G 150 848.1404 848.1362 848.0149

F 150 859.8331 859.8279 859.7100

E 150 874.6329 874.6282 874.5131

O 150 873.3249 873.3194 873.2012

C 150 892.2436 892.2354 892.1238

B150 909.8779 909.8635 909.7589

p 170 931.6454 931.6361 931.5274

N 170 936.6007 936.5917 936.4862

F 942.2379 942.2320 942.1255

G 951.6242 951.6140 951.5107

T 170 937.6776 937.6683

S 170 924.8486 924.8399 924.7359

R 170 906.6933 906.6798 906.5848

O 170 894.8490 894.8365 894.7451

M 170 876.7450 876.7335 876.6435

862.2277 862.2099

L 170 847.6273 847.6029 847.5195

J 828.3198 828.3015 828.2218

K 170 814.3689 814.3480 814.2672

J170 799.4161 799.3928 799.3116

K 784.8209 784.7933 784.7167

H 170 772.9112 772.8820 772.8077

G 170 760.8740 760.8469

F 170 753,9836 753.9511 753.8786 753.967 -17 +88

E 170 742.4761 742.4470 742.3776 742.462 -14 +34

M 732.0351 732.0052 731.9356 732.020 -15 +84

2336 711.6289 711.5977 711.5211 711.610 -19 +89

O 170 696.9291 696.9006 696.8260 696.909 -20 +83

C 170 679.9266 679.8966 679.8130 679.875 -52 +62

B 170 663.6361 663.6110 663.5239 663.521 -115 -3

N 660.6774 660.6518

2136 650.5808 650.5544

A 170 640.3877 640.3563 640.2610 640.225 -163 -36

Z 169 627.9321 627.9008 627.7922

Y 169 620.9336 620.8967

2024 616.3714 616.3073 616.1700

2033 619.1184 619.0645 618.9313

13
Table 2-1--Continued

Line IV: Las Vegas to Corn Springs, Nevada

I

BM I Elevation (meters)

Change in elevation

(millimeters)

p1935 1940-41 1949-50 1963 1935-63 1949-63

F 18 615.9320 615.8693 615.7354

K 169 614.4879 614.3879 614.2133 613.914 -574 -299

L 169 614.5946 614.5018 614.2447 613.886 -709 -359

M 169 626.5636 626.5269 626.4284

N 169 637.9769 637.9500 637.8571 637.812 -165 -45

E 18 651.5393 651.5228 *651126

P 169 668.2565 668.2405 668.1489 668.123 -133 -26

0169 688.2855 688.2722 688.1793 688.176 -110 -3

C18 698.8717 698.8601 698.861 -11

R 169 708.0353 708.0282 707.9229 707.932 -103 +9

5 169 718.6936 718.6935 718.5942 718.632 -62 +38

T 169 734.6913 734.6929 734.5981 734.645 -46 +47

B 18 747.6091 747.6160 747.5222 747.574 -35 +52

U 169 764.0221 764.0245 763.9407 763.995 -27 +54

A 18 775.3420 775.3386 775.2602 775.318 -24 +58

V 169 790.5902 790.5924 790.5141 790.580 -10 +66

Z17 806.0056 806.0074 805.9334 806.007 +1 +74

Line V: Las Vegas to Cane Springs, Nevada

V 170 592.4419 592.3850 592.2212 591.853 -589 -368

W 170 583.5067 583.4649 583.3676 583.209 -298 -159

X170 581.3484 581.3104 581.2303 581.184 -164 -46

Y 170 581.1051 581.0675 581.0011 581.018 -87 +17

Z 170 588.2399 588.1974 588.1339 588.169 -71 +35

A 171 592.4729 592.4286 592.3723 592.402 -71 +30

S 612.3152 612.2747 612.2179 612.250 -65 +32

B 171 617.5763 617.5359 617.4801

C 171 634.4268 634.3907 634.3263 634.363 -64 +37

P 166 644.7350 644.6967 644.6294 644.666 -69 +37

T 650.8084 650.7708 650.7057 650.738 -70 +32

D 171 664.6117 664.5742 664.5108 664.548 -64 +37

U 685.7054 685.6685 685.6045 685.644 -61 +40

E 171 699.0871 699.0533 698.9868 699,026 -61 +39

F 171 713.0530 713.0193 712.9583 712.996 -57 +38

V 735.5757 735.5408 735.4779 735.517 -59 +39

G 171 731.8667 731.8302 731.7666 731 .804 -63 +37

H 171 742.3380 742.3039 742.2380 742.275 -63 +37

P 171 748.7812 748.7491 748.6852 748.721 -60 +36

J 171 733.9843 733.9560 733.8899 733.929 -55 +39

* Bench mark reset

14
Table 2-1 -Continued

Line V: Las Vegas to Cane Springs, Nevada-Continued

BM

I

I ________________

Elevation (meters)

1935 1940-411949-50

Change in elevation

_j_(millimeters)

____1963 1935-631949-63 _______

K 171 717.6004 717.5724

X 709.3395 709.3116 709.2471 709.281 -59 +34

L 171 701.4764 701.4483 701.3864 701.417 -59 +31

W 160 969.9089 696.8824 696.8198

M 171 690.1895 690.1634 690.1070 690.134 -56 +27

X 160 689.6961 689.6707 689.6154 689.641 -55 +26

N 171 689.9125 689.8845 689.8316 689.855 -57 +23

Y 683.4715 683.4481 683.3896 683.416 -56 +26

Z 681.9690 681.9459 681.8866

Y 160 666.1381 666.1168 666.0627 666.087 -51 +24

Z 160 655.9948 655.9604 655.9094 655.928 -67 +19

A 1 651.6778 651.6458 651.5925 651.614 -64 +22

A 161 645.6414 645.6080 645.5572 645.579 -62 +22

B 161 641.0298 640.9970 640.9513 640.972 -58 +21

C 161 639.3150 639.2796 639.2425 639.259 -56 +17

D 161 638.1775 638.1512 638.1461 638.013 -165 -133

E 161 637.4817 637.4476

F 161 636.4197 636.4192 636.4589 636.489 +69 +30

D 1 639.8093 639.7792 639.7642 639.761 -48 -3

G 161 634.2167 634.1917 634.1750 634.172 -45 -3

H 161 631.5357 631.5107 631.5028 631.460 -76 -43

J 161 619.4155 619.3336 619.3597 619.357 -59 -3

E 1 619.8636 619.8345

K 161 614.0776 614.0475 614.0353 614.051 -27 +16

L 161 605.9734 605.9470 605.9219 605.936 -37 +14

M 161 602.4560 602.4317 602.4112 602.421 -35 +10

N 161 594.8283 594.8048 594.7977 594.813 -15 +15

P 161 586.7787 586.7527 586.7539 586.764 -15 +10

F 1 589.0488 589.0272 589.0102 589.030 -19 +20

Q 161 586.4773 586.4559 586.4454 586.474 -3 +29

R 161 576.5718 576.5486 576.5272 576.550 -22 +23

S 161 562.2231 562.1988 562.1828 562.199 -24 +16

T 161 545.2194 545.2146 545.2016

G 1 544.2067 544.2107

U 161 530.4982 530.4938 530.4783 530.480 -18 +2

V 161 519.6524 519.6564 519.6350 519.626 -26 -9

W161 503.1407 503.1391

H 1 484.3751 484.3707 484.3487 484.332 -43 -17

X 161 488.8772 488.8750 488.8626 *489.900

Moapa LaPlace 507.5787 507.5792 507.5625 507.559 -20 -3

* Bench mark reset

15
Table 2-1-Continued

Line V: Las Vegas to Cane Springs, Nevada-Continued

BM Elevation (meters)

Change in elevation

(millimeters)

1935 1940-41 1949-50 1963 1935-63 1949-63

Ii Reset 508.2275 508.2274 508.2113 *508209

J 1 508.1132 508.1120 508.0974 508.097 -16 0

K 1 510.9748 510.9679 510.9538 510.965 -10 +11

Li 514.1282 514.1164

Y 161 522.3020 522.3008 522.2925 522.285 -17 -7

Z 161 520.7514 520.7471 520.7405 520.738 -13 -2

A162 519.3154 519.3089 519.3103 519.317 +2 +7

B 162 524.8091 524.8013

C162 531.4374 531.4311 531.4119

D 162 530.8237 530.8181 530.8091 530.817 -7 +8

E 162 526.2410 526.2339 526.2283 526.234 -7 +6

F 162 526.5212 526.5352 526.5533 526.581 +60 +28

G 162 527.6390 527.6382 527.6442 527.656 +17 +12

H 162 526.6973 526.6924 526.6791 526.682 -15 +3

N 1 531.8613 531.8612 531.8505 531.853 -8 +3

J 162 536.2008 536.2023 536.2007 536.210 +9 +9

K 162 542.4236 542.4250 542.4194 542.420 -4 +1

L 162 553.0505 553.0540

M 162 561.6788 561.6829 561.6744 561.676 -3 +2

Rivet 570.8389 570.8402 570.8395

N 162 571.5654 571.5660 571.5639 571.558 -7 -6

P 162 582.0190 582.0211 582.0218 582.015 -4 -7

0 162 589.6361 589.6275 589.6260 589.549 -87 -77

R 162 6010142 601.0092 601.0075 600.985 -29 -23

S 162 609.8053 609.7961 609.7989 609,795 -10 -4

T 162 612.6530 612.6347 612.6342 *613.815

R 1 617.9456 617.9456 617.9456 617,946 0 0

Line VI: Moapa, Nevada, to Beaver Dam Creek, Ari zona

U50 468.0901 468.0961

W 50 463.8735 463.8719 463.8623

A 160 480.4906 480.4919 480.4738

X 50 509.0801 509.0770 509.0635

B 160 563.8805 563.8822

Y50 628.2211 6282327

C 160 627.3292 627.3439

Z50 631.0647 631.0795

D 160 630.7846 630.8026

A51 627.5886 627.6038

*Bench mark reset

16
Table 2-1 -Continued

Line VI: Moapa, Nevada, to Beaver Dam Creek, Arizona-Continued

BM Elevation

Change in elevation

(millimeters)

1935-63 1 949-63

E 160 616.7940 616.8030

B 51 613.9541 613.9626

F 160 617.7027 617.7115

C 51 621.5532 621.5612

G 160 626.4022 626.4039

D 51 632.3829 632.3820

H 160 640.9838 640.9777

E 51 641.8334 641.8291

J 160 639.5692 639.5638

F 51 633.9648 633.9604

K 160 629.2808 629.2767

G 51 634.7141 634.7097

L 160 598.0783 598.0759

H 51 533.9812 533.9721

M 160 501.7822 501.7863

N 160 487.8930 487.8811

J51 437.9480 437.9360

P 160 483.0318 483.0229

K 51 464.5973 464.5857

O 160 478.8535 478.8399

L 51 485.8216 485.8099

R 160 476.7454 476.7375

M 51 466.3354 466.3295

S 160 473.1548 473.1419

N 51 480,1006 480.0909

T 160 475.9028 475.8989

P 51 480.8922 480.8819

U 160 484.5833 484.5754

0 51 486.8128 486.8065

R 51 490.1284 490.1127

V 160 496.5020 496.4947

0+00 540.9453 540.9387

31+40.0 517.9033 517.8954

E 111 522.0585 522.0521

E 55 536.8544 536.8504

F ill 561.4935 561.4891

G 111 526.4270 526.4223

G 55 525.2395 525.2331

H 111 586.0457 586.0398

H 55 595.2214 595.2137

17
Table 2-1-Continued

Line VI: Moapa, Nevada, to Beaver Dam Creek, Arizona-Continued

Change in elevation

BM Elevation (meters) (millimeters)

1 1935 1940-41 1949-50 1963 1935-63 1949-63

Jill 590.2345 590.2251

508+50.0 557.1392 557.1352

K 111 559.8073 559.8008

K55 614.9709 614.9677

Line VII: Hackberry, Arizona, to Moapa, Nevada

B 53 1044.5758 1044.4895

B 125 1033.1282 1033.0342

3371 1027.3976 1027.3104

C53 1026.2804 1026.1926

C 125 1013.5035 101 3.4186

D53 1002.0574 1001.9715

D 125 989.1887 989.1091

E 53 976.8167 976.7433

E 125 966.9072 966.8389

3130 955.6578 955.5959

F 125 945.9433 945.8808

F 53 934.6039 934.5408

G 125 926.7680 926.7017

3015 918.9394 918.8657

H 125 911.9974 911.9250

G53 911.2727 911.1994

J 125 904.8909 904.8179

2968 905.2807 905.2043

K 125 901.7404 901.6688

H 53 903.6678 903.5979

L 125 907.1793 907.1067

2971 906.0155 905.9394

M 125 896.6208 896.5516

N 125 885.2128 885.1414

2879 877.9277 877.8532

P125 876.0183 875.9462

J 53 862.9324 862.8588

0125 854.3795 854.3103

2886 849.7900 849.7235

R 125 843.8636 843.7977

K53 842.0149 841.9472

S125 840.6315 840.5673

L53 840.1994 840.2125

T 125 840.2402 840.1919

M53 ____ 842.0033 841.9519 ______ ___________________________

18
Table 2-1--Continued

Line VII: Hackberry, Arizona, to Moapa, Nevada-Continued

BM

U 125

N 53

V 125

p 53

W 125

X 125

2860

V 125

Q 53

Z 125

R 53

A 126

S 53

B 126

T 53

C 126

U 53

D 126

V 53

E 126

W 53

F 126

X 53

G 126

H 126

V 53

J 126

K 126

Z 53

L 126

M 126

A 54

N 126

P 126

B 54

O 126

R 126

S 126

C54

T 126

Elevation

1935

848.0522

858.5970

862.0703

865.8584

868.9818

871.3362

871.9543

894.7302

931.7418

993.7496

1055.3384

1117.1713

1189.9439

1238.8428

1209.7249

1206.7 136

1173.9951

1157.3735

1149.0989

1134.1572

1094.8840

1069.0707

1053.5859

1025.1597

998.5941

987.8306

960.6528

940.8457

924.5651

951.5492

934.0025

9267102

914.1867

890.9268

869.8756

851.2786

837.6002

832.1673

843.4041

805.3659

848 .906 7

858.5520

862.0261

865.8103

868.9350

871.2781

871.8861

894.6738

931.6859

993.6940

1055.2825

1117.1125

1189.8817

1238.7769

1209.6584

1206.6470

1173.9215

1157.2987

1149.0196

1134.0797

1094.8037

1068.9972

1053.5168

1025.0885

998.5256

987.7580

960.5794

940.7727

924.4884

951.4706

933.9293

926.6379

914.1148

890.8526

869.8059

851.2043

837.5235

832.0931

843.3353

805.2972

868.9000

871.2398

871.8406

894.6392

931.6481

993.6514

1055.2403

1117.0692

1189.8363

1238.7314

1209.6110

1206.6118

1173.8953

1157.2738

1148.9985

1134.0598

1094.7896

1068.9823

1053.4983

1025.070 1

998.5037

987.7418

960.5657

940.7603

924.4802

951.4617

933.9152

926.6232

914.0995

890.8419

869.7924

851.1947

837.5152

832.0833

805.2859

1940-41 1963

Change in elevation

(millimeters)

1935-63 1949-63

19
Table 21-Continued

Line VII: Hackberry, Arizona, to Moapa, Nevada-Continued

BM I

flf935

U 126 785.3507

V 126 769.3156

D 54 783.1508

W 126 789.4613

X 126 789.4699

Y 126 747.9177

M 129 732.5711

E 54 715.2201

A 127 678.1258

B 127 654.3778

C 127 618.8328

0 127 594.3490

F 54 575.5368

E 127 543.9801

F 127 523.7244

G 127 496.3698

G 54 487.8288

H 127 445.1462

J 127 417.6781

K 127 389.1241

L 127 373.3758

M 127 379.2887

N 127 401.9111

P 127 406.8019

Q 127 412.2134

K 54 425.3930

R 127 433.0160

S 127 411.4468

T 127 386.0118

U 127 400.3334

V 127 410.5392

L 54 421.1277

W 127 431.9795

X 127 444.3123

Y 127 458.7561

Z 127 473.8422

N 129 491.1179

M 54 495.9036

P 129 512.1801

Q 129 521.6859

Change in elevation

Elevation (meters) (millimeters)

1940-41 1949-50 1963 1935-63 1949-63

785.2813 785.2729

769.2469 769.2405

783.0769 783.0710

789.3893 789.3811

789.3961 789.3885

747.8442 747.8386

732.4990 732.4948

715.1523 715.1450

678.0575 678.0553

654.3105 654.3071

618.7624 618.7655

594.2804 594.2839

575.4668 575.4722

543.9130 543.9181

523.6552 523.6675

496.3036 496.3140

487.7630 487.7748

445.0822 445.0994

417.6138 417.6310

389.0595

373.3129 373.3358

379.2371 379.2507

401.8505 401.8605

406.7391 406.7450

412.1529 412.1565

425.3311 425.3347

432.9560 432.9581

411.3830 411.3838

385.9505 385.9492

400.2832 400.2804

410.4844 410.4806

421.0730 421.0654

431.9210 431.9119

444.2516 444.2421

458.6968 458.6836

473.7821 473.7686

491.0619 491.0460

495.8741 4958604

512.1268 512.1102

521.6346 521.6168

20
Table 2-1-Continued

Line VII: Hackberry, Arizona, to Moapa, Nevada-Continued

BM

R 129

S 129

N54

T 129

U 129

V 129

P 54

W 129

X 129

V 129

Q54

Z 129

A 130

B 130

R 54

C 130

D 130

S 54

E 130

T 54

F 130

U 54

G 130

V 54

H 130

W 54

J 130

X 54

K 130

V 54

L 130

Z 54

M 130

A 55

N 130

B 55

P 130

C 55

Q 130

0 55

1935

540.1408

552.9010

577.9009

609.8734

638.4526

656.2884

663.1099

701.8534

732.1964

736.9187

719.7435

686.0295

656.1732

630.8648

626.6026

611.4157

576.2883

566.0954

563.2080

585.1687

584.3111

592.4627

612.9289

631.4579

646.2515

659.4976

638.8046

611.2334

539.4799

532.3950

514.2756

490.5450

500.3563

511.5651

542.8774

564.9350

605.3502

613.4258

634.2979

669.0994

Change in elevation

Elevation (meters) (millimeters)

1940-41 1949-50 1963 1935-63 1949-63

540.1035

552.8567

577.8496

609.8213

638.4021

656.2378

663.0599

701.8073

732.1521

736.8730

719.6987

685.9861

656.1329

630.8286

626.5672

611.3823

576.2559

566.0647

563.1802

585.1378

584.2949

592.4408

612.9136

631.4415

646.2396

659.4878

638.7940

611.2217

539.4739

532.3922

514.2710

490.5450

500.3628

511.5740

542.8972

564.9303

605.3518

613.4253

634.2979

669.0924

540.0627

552.8447

577.8347

609.8045

638.3821

656.2162

663.0371

701.7838

732.1205

736.8446

719.6696

685.9598

656.1082

630.8045

626.5415

611.3560

576.2317

566.0395

563.1524

585.1075

584.2584

592.4119

612.8781

631.4076

646.2084

659.4570

638.7605

611.1916

539.4451

532.3647

514.2421

490.5106

500.3301

511.5427

542.8644

564.8820

605.3222

613.3964

634.2663

669.0608

21
Table 2-1 -Continued

Line VII: Hackberry, Arizona, to Moapa, Nevada-Continued

BM

Change in elevation

(millimeters)

1935-63 1 94

R 130 680.8074 680.7990 680.7641

A 50 697.6355 697.6268 697.5946

V 178 722.1671 722.1595 722.1290

B 50 749.2428 749.2339 749.2023

W 178 748.0064 747.9931 747.9638

C 50 718.5695 718.5523 718.5185

X 178 708.9304 708.9121 708.8806

D 50 680.4206 680.4055 680.3800

Y 178 661.9767 661.9555 661.9343

Z 178 649.1326 649.1146 649.0914

E 50 626.3339 626.3185 626.2997

F 50 609.1735 609.1535 609.1403

U 162 605.1612 605.1426 605.1269

V 162 586.2233 586.2145 586.2156

G 50 576.2263 576.2070 576.1979

W 162 581.5101 581.4886 581.4820

X 162 562.1790 562.1628 562.1505

V 162 552.7078 552.6854 552.6793

Z 162 541.1694 541.1466 541.1406

A 163 526.3128 526.2882 526.2858

B 163 513.8044 513.7807 513.7778

C 163 496.8793 496.8615 496.8620

D 163 477.1865 477.1646 477.1626

H 50 479.1713 479.1496 479.1454

1648 502.4945 502.4768 502.4698

E 163 493.1724 493.1659 493.1610

F 163 478.1098 478.1147 478.1101

G 163 468.8491 468.8621 468.8576

J 50 460.0335 460.0521 460.0502

H 163 452.2097 452.2303 452.2320

J 163 446.0717 466.0916 446.0974

K 163 441.2091 441.2302 441.2364

1428 435.3828 435.4055 435.4098

L 163 431.8038 431.8281 431.8286

M 163 425.6930 425.7168 425.7194

N 163 393.6370 393.6610 393.6618

P 163 383.2591 383.2857 383.2863

U 178 381.5655 381.5928 381.5930

o 163 378.4809 378.5082 378.5076

K 50 366.5867 366.6090 366.6068

Elevation (meters)

1940-41 194

22
Table 2-1-Continued

Line VII: Hackberry, Arizona, to Moapa, Nevada-Continued

Change in elevation

BM Elevation (meters) (millimeters)

_______

______________ 1935 1940-41 1949-50 _____ 1963 1935-63 1949-63

S 163 369.1488 369.1730 369.1789

1 163 430.9566 430.9859 430.9931

U 163 454.4896 454.5144 454.5223

V 163 476.7401 476.7506 476.7545

W 163 494.2097 494.2088 494.2090

X 163 447.6748 447.6666 447.6636

Y 163 432.4297 432.4173 432.3974

Z 163 435.4432 435.4363 435.4313

A 164 574.2664 574.2586 574.2571

B 164 573.8871 573.8782 573.8776

C 164 576.6373 576.6235 576.6264

D 164 577.3872 577.3727 577.3774

E 164 575.9048 575.8917 575.8949

F 164 572.0472 572.0337 572.0379

G 164 568.4704 568.4587 568.4627

H 164 565.7350 565.7200 565.7231

J 164 568.0405 568.0279 568.0344

K 164 565.9203 565.9095 565.9164

L 174 564.6241 564.6125 564.6217

M 164 567.7731 567.7613 567.7716

N 164 567.6669 567.6569 567.6646

P 164 569.0957 569.0828 569.0950

o 164 570.4987 570.4882 570.4982

R 164 572.6276 572.6189 572.6290

S164 527.8059 527.7995 527.8016

1 164 487.3650 487.3592 487.3550

U 164 472.2958 472.2906 472.2850

V 164 461.9338 461.9300 461.9218

W164 450.4154 450.4114 450.4014

X 164 438.9921 438.9862 438.9745

Y 164 422.2125 422.2062 422.1955

Z164 411.3175 411.3123 411.2999

A 165 408.1869 408.1809 408.1673

B 165 389.1005 389.0944 389.0802

C 165 387.2599 387.2520 387.2376

D 165 385.6955 385.6848 385.6660

E 165 384.4702 384.4514 384.4286

F 165 385.2877 385.2616

G 165 389.6355 389.6135 389.5837

H 165 _____

390.9407 390.9220 390.8979 _____ _____

23
Table 2-1--Continued

Line VII: Hackberry, Arizona, to Moapa, Nevada-Continued

BM Elevation (meters) ______

I

___ J

Change in elevation

_ (millimeters)

1935 1940-41 1949-50 1963 I 1935-63 1949-63

34B 1043.3872 1043.4415 1043.3312

S175 1004.0715 1004.1167

R 175 967.2289 967.2709 967.1640

P 175 888.7678 888.7931 888.7002

N 175 892.7265 892.7547 892.6649

M 175 901.2260 901.2619 901.1643

L 175 942.2421 942.2774 942.1901

K175 901.8772 901.9116 901.8191

35 B 942.4596 942.4859 942.4031

J 175 947.1608 947.1883 947.1037

H 175 879.1667 879.1914 879.1109

G 175 982.0767 982.1135 982.0276

36B 1034.8658 1034.9192 1034.8203

F 175 1060.4367 1060.4917 1060.3945

E 175 1133.6050 1133.6609 1133.5703

37B 1131.4962 1131.5544 1131.4657

D 175 1049.7486 1049.7904 1049.7193

C 175 992.8933 992.9228 992,8674

B 175 946.9397 946.9594 946.9080

38 B 945.2747 945.2878 945.2393

A 175 977.5579 977.5806 977.5288

Z 174 920.4330 920.4461 920.3948

Y 174 885.0971 885.1017 885.0548

39B 851.8736 851.8750 851.8299

X 174 791.0687 791.0670 791.0207

W 174 764.8496 764.8477 764.8059

V 174 773.8962 733.8954 733.8535

U 174 706.4007 706.3975 706.3598

T 174 678.9212 678.9195 678.8793

40 B 648.23 1 1 648.2477

S174 617.2401 617.2291 617.2016

R 174 5870604 58T0424 587.0239

Line IX: 4 miles west of Boulder City, Nevada, to 10 miles north of Chloride, Arizona

E 167 707.8742 707.8610 *705.968

F 167 714.9842 714.9688 *713.310

G 167 724.3519 724.3321 724.2359 724.347 -5 +111

H 167 731.5412 731.5236 731.4285 731.542 +1 +114

J 167 740.8730 740.8507 *739.787

*Bh mark reset

24
Table 2-1-Continued

Line IX: 4 miles west of Boulder City, Nevada, to 10 miles north of Chloride, Arizona-Continued

BM Elevation (meters)

Change in elevation

(millimeters)

_______ _______

1935 ____

______

_ 1940-41 _____ 1949-50 1963 1935-63 1949-6 _____________

L 167

_

755.4180 755.3905 755.3084 755.428 +10 +120

M 167 766.3665 766.3366 766.2428 766.360 -6 +117

8169 764.2284 764.2006 764.1093 764.228 0 +119

C 169 776.3039 776.2722 776.1846 776.303 -1 +118

N 167 740.1006 740.0661 739.9832 740.098 -3 +115

P 167 683.3375 683.3041 683.2266 683.324 -14 +97

Q 167 676.4023 676.3717 676.2964

R 167 647.2255 647.1912 647.1198 647.206 -20 +86

S 167 624.2652 624.2332 624.1609 624.240 -25 +79

T 167 606.5918 606.5597 606.4887 606.561 -31 +72

U 167 578.3922 578.3642 578.2931 578.358 -34 +65

V 167 558.4837 558.4532 558.3827 558.443 -41 +60

W 167 545.8486 545.8176 545.7496 545.809 -40 +59

X 167 525.1424 525.1122 525.0430 525.098 -44 +55

V 167 510.9409 510.9100 510.8453 510.902 -39 +57

Z 167 509.8795 509.8466 509.7816 509.832 -48 +50

1665.78 507.8987 507.8652 507.8010 507.851 -48 +50

A 168 522.8645 522.8312 522.7651

8168 526.8796 526.8437 526.7711 526.820 -60 +49

C 168 533.0572 533.0216 532.9460 532.994 -63 +48

0 168 546.3782 546.3347 546.2551 546.298 -80 +43

E 168 519.7271 519.6840 519.6008 519.639 -88 +38

F 168 494.2293 494.1818 494.0933 494.121 -108 +28

0169 479.8378 479.7976 479.7090 479.727 -111 +18

E 169 434.4310 434.3880 434.3062

F 169 393.3532 393.3114

G 169 337.1442 337.1088 337.0408 337.055 -89 +14

H 169 281.3563 281.3150 281.2541 281.272 -84 +18

J 169 235.2160 235.1788

N 16 215.3956 215.3627

L 174 205.8249 205.7696 205.6993 205.697 -128 -2

M 174 205.8367 205.7713 205.7009 205.701 -136 0

0 174 214.8902 214.8243 214.7470 214.749 -141 +2

C 136 214.8942 214.8257 214.7554 214.758 -136 +3

Z 135 205.8365 205.7687 205.7015 205.702 -134 0

V 135 205.8264 205.7685 205.7036 205.705 -121 +1

A 134 222.4716 222.4191

B 134 282.8890 282.8401 282.7739 282.792 -97 +18

C 134 327.8787 327.8308 327.7646 327.783 -96 +18

D 134 310.5059 310.4557 310.3926 310.411 -95 +18

25
Table 2-1 -Continued

Line IX: 4 miles west of Boulder City, Nevada, to 10 miles north of Chloride, Arizona-Continued

Change in elevation

BM Elevation (meters) ____________

(millimeters)

1935 1940-41

____

1949-50

___-

1963 1935-63 1949-63 ________

E 134 297.0055 296.9576 296.9000 296.913 -93 +13

F 134 322.2753 322.2284 322.1683 322.179 -96 +11

G 134 373.9699 373.9315 373.8671 373.880 -90 +13

U 173 474.3783 474.3311 474.2378 474.240 -138 +2

V 173 456.6559 456.6097 456.5217 456.525 -131 +3

W173 440.2458 440.1974 440.1092 440.118 -128 +9

X 173 424.7247 424.6724 424.5854 424.595 -130 +10

Y173 408.5563 408.5094 408.4323 408.440 -116 +8

Z173 397.7309 397.6910 397.6159 397.621 -110 +5

A174 389.1720 389.1253 389.0508 389.054 -118 +3

D 174 385.7668 385.7135 385.6364 385.641 -126 +5

C174 379.5752 379.5172 379.4440 379.449 -126 +5

E 174 375.8266 375.7698 375.6992 375.705 -122 +6

K 174 377.0976 377.0299 376.9676 376.974 -124 +6

F 174 375.8028 375.7423 375.6735 375.683 -120 +9

J 174 375.8240 375.7695 375.7163 375.733 -91 +17

G 174 375.7931 375.7355 375.6700 375.682 -111 +12

H 174 375.8119 375.7467 375.6808 375.693 -119 +12

0135 375.8013 375.7373 375.6720 375.686 -115 +14

R 135 375.7964 375.7413 375.6776 375.692 -104 +14

U 135 375.8412 375.7871 375.7362 375.756 -85 +20

S135 375.8022 375.7428 375.6796 375.692 -110 +12

1135 375.8292 375.7738 375.7122 375.723 -106 +11

V135 377.1544 377.0996 377.0342 377.044 -110 +10

W135 377.1318 377.0764 377.0060 377.013 -119 +7

X 135 391.1660 391.1034 391.0301 391.039 -127 +9

H134 441.2318 441.1837 441.1099 441.125 -107 +15

J 134 442.1861 442.1421 442.0694 442.087 -99 +18

K 134 396.2704 396.2283 396.1606 396.164 -106 +3

L 134 401.4428 401.4059 401.3381 401.351 -92 +13

C 256 396.3603 396.2933 396.308 +15

M 134 417.3278 417.2963 417.2328 417.259 -69 +26

N 134 446.3865 446.3521 446.2899 446.325 -61 +35

P 134 465.2856 465.2510 465.1887 465.225 -61 +36

0134 489.2536 489.2194 489.1587 489.195 -59 +36

R 134 480.3080 480.2736 480.2113 480.249 -59 +38

S 134 470.9512 470.9135 470.8529 470.889 -62 +36

T134 471.0910 471.0539 470.9949 471.032 -59 +37

U 134 503.6753 503.6398 503.5794 503.624 -51 +45

V 134 529.7834 529.7478 529.6881 529.735 -48 +47

26
Table 2-1-Continued

Line IX: 4 miles west of Boulder City, Nevada, to 10 miles north of Chloride, Arizona-Continued

Change in elevation

BM L Elevation (meters) ______ -

J_jmiIlimeters)

1940-41 1949-50 1963 1935-63 194

W 134 558.1310 558.0943 558.0327 558.087 -44 +54

P 135 557.7915 557.7550 557.6923 557.745 -47 +53

X 134 578.4971 578.4607 578.3974 578.454 -43 +57

1934.35 588.9416 588.9046 588.8409 588.898 -44 +57

2043.88 622.3271 622.2877 622.2191 622.284 -43 +65

Y134 654.4611 654.4220 654.3526 654.423 -38 +70

Z 134 665.5479 665.5081 665.4371 665.510 -38 +73

A 135 673.0838 673.0428 672.9726 673.048 -36 +75

B 135 665.7847 665.7439 665.6745 665.746 -39 +72

C 135 665.5784 665.5393 665.4710 665.542 -36 +71

D 135 661.9428 661.9084 661.8374 661.905 -38 +68

E 135 647.3983 647.3669 647.2968 647.359 -39 +62

F 135 639.5849 639.5486 639.4811 639.543 -42 +62

2165.03 659.3009 659.2585 659.1941 659.258 -43 +64

G 135 673.1301 673.0833 673.0222 673.092 -38 +70

H 135 685.9887 685.9457 685.8779 685.950 -39 +72

2218.05 675.4719 675.4318 675.3620 675.431 -41 +69

J 135 628.1500 628.1092 628.0435 628.106 -44 +62

1992.29 606.6259 606.5808 606.5198 606.576 -50 +56

N 135 583.0371 582.9938 582.9320 582.983 -54 +51

1919.15 584.3809 584.3350 584.2753 584.324 -57 +49

2118.75 645.3096 645.2620 645.1988 645.258 -52 +59

K 135 690.6351 690.5832 690.5239 690.587 -48 +63

Builder 1935 688.4759 688.4230 688.3720 688.450 -26 +78

R.M. 1 688.1203 688.0670 688.0098 688.070 -50 +60

R.M. 2 688.5067 688.4543 688.4083

2258.32 687.8259 687.7889 687.7787 687.851 +25 +72

R.M.3 691.0127 690.9600 690.9378 691.007 -6 +69

2288.55 697.0380 696.9829 696.9512 697.011 -27 +60

L 135 711.1432 711.0797 711.0310 711.083 -60 +52

M 135 704.7676 704.7054 704.6516

F 121 714.7370 714.6674 714.6268

G 121 733.3441 733.2737 733.2293

H 121 729.9892 729.9163 729.8795

J 121 732.7414 732.6648 732.6343

K 121 735.8984 735.8180 735.7910

L 121 738.2562 738.1780 738.1472

M 121 746.0991 746.0276 745.9884

P 121 765.1204 765.0542 765.0125

0 121 _______776.5499 776.4856 776.4450

27
Table 2-1-Continued

Line IX: 4 miles west of Boulder City, Nevada, to 10 miles north of Chloride, Arizona-Continued

Change in elevation

BM L ______

Elevation (meters) _____] (millimeters)

fl35 1940-41 1949-50 1963 1935-63 194

R 121 788.1402 788.0772 788.0372

S 121 800.4565 800.3975 800.3549

T121 813.4114 813.3541 813.3104

U 121 819.0010 818.9508 818.9064

980+73 826.6792 826.6283 826.5838

954+01.25 831.5126 831.4605 831.4128

933+55 836.7323 836.6793 836.6287

V 121 844.3755 844.3166 844.2735

873+31.66 851.3101 851.2546 851.2143

848+51.66 857.8905 857.8414 857.8018

825+00 862.9715 862.9274 862.8903

W 121 870.1578 870.1070 870.0654

770+00 879.6244 879.5837 879.5466

743+01.25 887.8383 887.7938 887.7587

713+01.25 897.5371 897.4893 897.4534

X 121 904.0177 903.9653 903.9307

664+10 911.5983 911.5487 911.5077

V 121 918.0234 917.9694 917.9267

614+00 925.7264 925.6712 925.6287

Z 121 937.4167 937.3569 937.3142

567+45 941.9395 941.8837 941.8401

541+20 950.8947 950.8328 950.7892

Line X: Las Vegas to Searchlight , Nevada

A 166 596,4059 596.3160 596.1170

S51 565.5255 565.4816

B 166 556.4184 556.3646 *555.546

151 551.8639 551.8277 551.7483

C 166 540,9927 540.9608

U51 519.7438 519.7105 519.6214

D 166 510.6398 510.5971

V 51 504.4641 504.4220 *504088

E 166 501.1667 501.1188 501.0465

W51 504.2330 504.1841 504.1128 504.155 -78 +42

F 166 517.5240 517.4783

X 51 546.5950 546.5536

G 166 589.1780 589.1423 589.0567 589.123 -55 +66

Y51 621.0475 621.0121 620.9288

H 166 645.5509 645.5191 645.4323 645.514 -37 +82

* Bench mark reset

28
Table 2-1 -Continued

Line X: Las Vegas to Searchlight, Nevada-Continued

Change in elevation

BM E'evation (meters) I

(miUimeters)

1 1935 1940-41 1949-50 1963 I 1935-63 1949-63 _______ _____

Z 51 660.7085 660.6844 660.5958 660.682 -26 +86

J 166 692.1899 692.1713 692.0744 692.171 -19 +97

A 109 721.5448 721.5326 721.4316 721.540 -5 +108

A 169 705.7972 705.7833 708.162 +2,365

B 109 685.8298 685.8182 685.7195 685.823 -7 +103

K 166 628.2995 628.2862 628.1897 628.284 -16 +94

C 109 574.1625 574.1452 574.0563 574.149 -13 +93

L 166 537.9377 537.9172 537.8324 537.920 -18 +88

0 109 531.0581 531.0410 530.9516 531.042 -16 +90

M 166 521.4701 521.4499 521.3598 521.448 -22 +88

1712 521.2341 521.2124 521.1260 521.216 -18 +90

U 148 521.8422 521.8191 521.7280 521.819 -23 +91

V 148 521.5301 521.5129 521.4203 521.510 -20 +90

W 148 524.3348 524.3182 524.2252 524.315 -20 +90

X 148 525.3969 525.3770 525.2807 525.379 -18 +98

Y 148 526.0683 526.0460 525.9477 526.049 -19 +101

Z 148 528.4737 528.4484 528.3533 528.453 -21 +100

A 149 540.4899 540.4626 540.3662 540.468 -22 +102

H 109 568.5543 568.5320 568.4305 568.537 -17 +107

B 149 596.1745 596.1546 596.0494 596.164 -10 +115

J 109 620.4705 620.4534 620.3381 620.462 -8 +124

C149 642.2699 642.2603 642.1336 642.266 -4 +132

K 109 62.7123 662.7103 662.5761 662.712 0 +136

D 149 689.7818 689.7835 689.6445 689.786 4 142

L 109 723.4815 723.4813 723.3412 723.489 +7 +148

E 149 766.5220 766.5290 766.3892 766.542 +20 +153

M 109 803.7414 803.7439 803.6051 803.756 +15 +151

F 149 836.3213 836.3193 836.1838 836.329 +8 +145

G 149 892.7438 892.7405 892.6073 892.751 +7 +144

P109 914.3253 914.3244 914.1889 914.333 +8 +144

H 149 935.9159 935.9083 935.7745 935.924 +8 +150

0 109 955.4355 955.4847 955.3470 955.498 ^62 +151

J149 965.5637 965.5561 965.4211 965.571 +7 +150

R 109 982.4149 982.4083 982.2715 982.424 +9 +152

K 149 1004.4790 1004,4819 1004.3421 1004.495 +16 +153

S 109 1027.2303 1027.2302 1027.0940 1027.245 +15 +151

3400 1035.9446 1035.9469 1035.8105 1035.960 +15 +150

L 149 1046.9935 1046.9970 1046.8609 1047.014 +20 +153

1 109 1077.4600 1077.4425 1077.3187 1077.473 +13 +154

M 149 1095.3994 1095.3792 1095.2617 1095.430 +31 +168

*

Bench mark reset

29
Table 2-1 -Continued

Line X: Las Vegas to Searchlight, Nevada-Continued

Change in elevation

BM I Elevation (meters) (millimeters)

1940-41 1949-50 1963 1935-63 1949-63 ___________

U109 1114.9092 1114.8870 1114.7728 1114.940 +31 +167

3730 1136.6402 1136.6231 1136.4982 1136.669 +29 +171

N 149 1107.6142 1107.5946 1107.4731 1107.643 +29 +170

Line Xl: 10 miles north of Las Vegas, Nevada, to 35 miles north of Chloride, Arizona

Q166 619.3596 619.3162 619.2497 619.287 -73 +37

R 166 600.3246 600.2766 600.2110 600.252 -73 +41

S 166 590.9217 590.8710 590.8062 590.844 -78 +38

T 166 582.5285 582.4776 582.4083 582.165 -363 -243

U 166 593.9779 593.9318 593.8622 593.914 -64 +52

V 166 620.2826 620.2315 620.1596 620.222 -61 +62

W166 634.0398 633.9858 633.9149 633.984 -56 +69

X 166 617.0898 617.0350 616.9655 617.025 -65 +59

V 166 599.3496 599.2893 599.2237 599.283 -67 +59

Z166 579.5850 579.5216 579.4615 579.508 -77 +46

A167 551.0905 551.0171 550.9563 551.006 -84 +50

B167 558.8964 558.8202 558.7587 558.811 -85 +52

C167 557.6524 557.5747 557.5114 557.562 -90 +51

D 167 533.1061 533.0227 532.9630 533.012 -94 +49

H 168 536.4695 536.3774 536.3153 536.369 -101 +54

J 168 571.9291 571.8364 571.7698 571.828 -101 +58

K 168 619.8064 619.7179 619.6510 619.709 -97 +58

L 168 674.7808 674.6906 674.6241

M 168 737.6210 737.5206 737.4623 737.524 -97 +62

N 168 685.1446 685.0421 684.9827 685.042 -103 +59

P 168 629.7290 629.6199 629.5659 629.620 -109 +54

Q168 574.9143 574.8046 574.7508 574.793 -121 +42

*R 168 526.8011 526.6857 526.6322 526.670 -131 +38

S168 474.3341 474.2117

U170 597.1627 597.0462 596.9929 597.045 -118 +52

H 173 604.3127 604.2002 604.1447 604.192 -121 +47

Z 172 553.0291 552.9163 552.8639 552.902 -127 +38

J 173 526.9593 526.8476 526.7966 526.834 -125 +37

V 172 498.8619 498.7534

K 173 488.9986 488.8907 488.8372 488.875 -124 +38

X 172 503.3366 503.2282 503.1793 503.216 -121 +37

L173 515.8437 515.7338 515.6815 515.717 -127 +35

W172 532.8054 532.7022 532.6493 532.694 -111 +45

M 173 557.6490 557.5384 557.4871 557.532 -117 +45

V 172 570.3472 570.2370 570.1821 570.227 -120 +45

*A 173 550.7845 550.6707 550.7182 550.755 -29 +37

*

Bench mark reset

30
Table 2-1-Continued

Line XI: 10 miles north of Las Vegas, Nevada, to 35 miles north of Chloride, Arizona-Continued

Change in elevation

BM ______

Elevation (meters) 1 (millimeters)

1935 1940-41 1949-50 1963 T 1935-63 194

U 172 595.2820 595.1735 595.1196 595.170 -112 +50

T 172 623.7124 623.6059 623.5475 623.608 -104 +60

S 172 661.0292 660.9181 660.8598 660.927 -102 +67

N 173 679.9593 679.8432 679.7918 679.860 -99 +68

R 172 696.4189 696.3002 696.2498 696.320 -99 +70

P173 714.2253 714.1094 714.0575 714.131 -94 +73

o 172 736.6823 736.5666 736.5141 736.592 -90 +78

0173 708.2675 708.1564 708.1234 708.241 -27 +118

P 172 691.0658 690.9566 690.9087 690.985 -81 +76

N 172 637.1047 636.9945 636.9410 637.007 -98 +66

S173 618.2547 618.1452 618.0865 618.147 -108 +61

M 172 597.9426 597.8321 597.7748 597.828 -115 +53

T173 580.9883 580.8780 580.8227 580.872 -116 +49

L 172 567.8658 567.7570 567.7047

K 172 545.8283 545.7160 545.6617 545.708 -120 +46

J 172 530.7755 530.6608 530.6092 530.651 -125 +42

H 172 508.2401 508.1281

1618 B 493.3775 493.2640 493.2144 493.252 -126 +38

G 172 492.6757 492.5609 492.5114 492.550 -126 +39

F 172 476.6946 476.5791 476.5318 476.570 -125 +38

E 172 462.0646 461.9500 461.8989 461.934 -131 +35

D 172 443.1696 443.0526 442.9992 443.036 -134 +37

C 172 420.5034 420.3842 420.3302 420.366 -137 +36

B 172 397.4192 397.3002 397.2466 397.276 -143 +29

B 173 401.0312 400.9126 400.8572 400.888 -143 +31

C 173 399.0861 398.9666 398.9126 398.943 -143 +30

A 172 378.3464 378.2249 378.1722 378.199 -147 +27

Line continues at Detrital Wash Gage

U 120 372.9261 372.8298 372.7085 372.726 -200 +18

T 120 381.6922 381.5968 381.5606 381.576 -116 +15

5120 386.8406 386.7474 386.7024 386.721 -120 +19

R 120 392.4618 392.3650 392.3204 392.339 -123 +19

0120 396.7546 396.6577 396.6123 396.631 -124 +19

P 120 404.6594 404.5659 404.5173 404.537 -122 +20

N 120 406.8016 406.7066 406.6591 406.680 -122 +21

M 120 414.1629 414.0677 414.0188 414.042 -121 +23

1< 120 425.3583 425.2608 425.2163 425.242 -116 +26

J 120 430.5282 430.4310 430.3857 430.412 -116 +26

31
Table 21 -Continued

Line continues at Detrital Wash Gage -Continued

BM

H 120

F 120

B 120

A 120

W 119

V 119

S 119

R 119

Q 119

P119

N 119

M 119

L 119

K 119

J 119

H 119

G 119

F 119

E 119

D 119

C 119

B 119

A 119

Elevation

1935

437.2917

446.8332

474.3705

491.4185

501.0701

491.0919

520.5318

544.0001

556,3500

575.7561

586.8172

600.7776

611.5263

620.2487

626.4799

658.3606

678.6425

689.4392

698.7463

670.3047

667.3118

685.0971

710.4912

1940-41

437.1937

446.7363

474.2753

491.3267

500.9792

491.0019

520.4429

543.9180

556.2715

575.6772

586.7378

600.7058

611.4544

620.1730

626.4060

658.2970

678.5812

689.3790

698.6917

670.2366

667.2426

685.0323

710.4269

1949-50

437.1483

446.6907

474.2321

491.2813

500.9328

490.9603

520.3987

543.8669

556.2193

575.6226

586.6809

600.6486

611.3992

620.1232

626.3575

658.2393

678.5170

689.3172

698.6300

670.1858

667.1962

684.9830

710.3751

437,177 -115 +29

446.718 -115 +27

474.263 -107 +31

491.310 -108 +29

500.963 -107 +30

490.987 -105 +27

520.430 -102 +31

543.905 -95 +38

556.255 -95 +36

575.664 -92 +41

586.724 -93 +43

600.693 -85 +44

611.445 -81 +46

620.169 -80 +46

626.403 -77 +45

658.288 -73 +49

678.572 -70 +55

689.374 -65 +57

698.689 -57 +59

670.238 -67 +52

667.248 -64 +52

685.037 -60 +54

710.429 -62 +54

I (1')

Change in elevation

(millimeters)

Ifl') ')

32
McCullough and Eldorado Mountain Ranges. Regional

tectonics are shown in Figures 2-2 and 2-3.

Structural basins containing sedimentary deposits form

intermountain valleys. Mountains and valleys were

formed by the mechanics of block faulting, a

seismological process where large blocks of the earth's

crust were uplifted or lowered along major faults. The

faults have substantial displacement ranging from a few

feet to several thousand feet. The upfautted blocks

have been eroded to the present mountain forms.

Diverse fluvial and lacustrial sediments of Tertiary to

Quaternary age are deposited on the down-faulted

blocks. The Grand Wash Cliffs, formed by the Grand

Wash fault, separate the Basin and Range Physiographic

Province from the Colorado Plateau Physiographic

Province at the head of Lake Mead. The Grand Wash

fault has been traced for more than 110 miles. The area

west of the fault is believed to have dropped, relative

to the area east of the fault, about 16,000 feet. Lake

Mead is surrounded by a large number of gravity faults

in the underlying rock formations. The presence of the

vast weight of water in Lake Mead has caused minor

earth tremors, but there has been no evidence of

violent earth crustal movements. These gravity faults

are known to be relatively inactive in the Quaternary

period.

Analysis of Releve/ing Data

Releveling data of 1963 and the Coast and Geodetic

Survey elevations, based on their "special" adjustment,

generally indicate the reservoir area of Lake Mead

made a rebound since the 1948-49 survey.

Lines were drawn connecting points of equal change in

elevation for the periods 1935-63 (Figure 2-2) and

1949-63 (Figure 2-3) using the 1963 level data.

Rebound or subsidence in areas between the releveled

lines were interpolated to indicate the pattern of

vertical movement. The areas of vertical movement

were delineated by contours of increasing or decreasing

elevations determined from relevel data. Broken lines

were drawn to indicate areas where releveling was not

run in 1963 and where releveled lines were relatively

far apart. In these areas, 1964 "supplemental" Coast

and Geodetic Survey data were used to estimate the

trend of movement.

Areas of subsidence and rebound are evident in the

1935-63 change in elevation map (Figure 2-2).

Rebound areas are indicated in the upper Colorado

River and upper Virgin River arms of Lake Mead and

subsidence indicated in the other areas. Most of the

subsidence occurred between 1935 and 1963 in the Las

Vegas area. The land surface of Las Vegas Valley has

subsided from Henderson northeasterly through Las

Vegas to Nellis Air Force Base. A maximum subsidence

of 709 millimeters (mm) appears at the intersection of

Level Lines IV and V at Las Vegas. A large area of

subsidence enclosing both Boulder and Virgin Basins,

with pronounced depressions near the center of each

basin, is indicated for the period between 1935 and

1963. The Boulder Basin depression has a depth of 40

mm and is separated from the Las Vegas depression by

the more stable Frenchman Mountain ridge composed

of quartzite, limestone, and conglomerate formations.

A strong fault zone on the western edge of a

Pre-Cambrian granite in Boulder Canyon bordering

Boulder Basin on the east and other existing gravity

faults (vertical breakage planes) south of Hoover Dam

and north and west of Boulder Basin possibly have

some effect on the Boulder Basin depression. The

depression could have been influenced by the more

easily compressible and flexible mid-Cenozoic to recent

formations comprising the floor of this basin. The

Virgin Basin shows a maximum subsidence of 200 mm.

Gravity faults in rock formations surrounding Boulder

Wash have possibly influenced the shape of this

depression.

For the 1949-63 period, the area between Hoover Dam

and the mouth of Detrital Wash has remained relatively

stable (see Figure 2-3). The rebound in Boulder Basin

and Virgin Basin since 1949, varies between 0 and 40

mm. The relevel data have again disclosed an enlarged

depression in Las Vegas Valley which correlates

strongly with changes in ground-water levels during the

same time period and further substantiates the theory

that subsidence in Las Vegas Valley is due to removal

of ground water. It is generally concluded that

subsidence in the Lake Mead area since 1949 has

ceased and the formations underlying the reservoir are

in a state of rebound.

Three reasons were suggested2' for subsidence: (1)

elasticity of the underlying rocks, (2) movement along

existing faults, and (3) compaction of alluvial deposits

and loosely consolidated formations on the reservoir

bottom. The 1949 relevel data support the second and

third reasons. The first is supported by the 1963 relevel

data.

Earthquake epicenters have been located by

seismographic methods at 1.5 miles east-northeast, 4

miles west and about 10 miles northwest of Hoover

Dam. An earthquake, that occurred in this locality

shortly before the 1963 releveling, could have

influenced the rebound in Boulder Basin as determined

by the 1963 relevel data.

' Geological Survey, "Comprehensive Survey of Sedimentation in Lake Mead, 1948-49," Professional Paper 295,

254 p, 1960.

33
5 0 5 0 5 20

SCOLE OF MILES

Contours in mU meters

0CANE SPRINGS

50 °

/ \\\

V

/ / / 7

)

I > / /

// /1 //

i

'S J

°RING CI" I, /

LAF d/

/

f/I

0BEAuR DAM GrEEK

+

,,,

ViIi

\\\ \(:I

Y(

-

'no

;

BOULDE CITY I

/ I

/ I

/

I /

/

/

\

70 /

/

I

/

)

/ /I /

/

(

\

j/ ) \\ \

\

4

/ I // /1 L i4// \\ /

/

/

_

( -

/

/ I

iii

--'-V /

/

6O / / /

" /

/

/

/

I

/

'-, /

7 /

-1'40

0NIPTON

mit

-' zn

0SEARCIR,IGI-IT -

as

EXPLANATION

Chnnqen'elevnflnr confnurn based

or npeoiol od1untmentn of 963 seleveong

ChOnge - fl - elevoron COstOurS bused nsf

suppIessefliusy edjusimer of 964

rUfOus en

- 60 rdICGsPS subsidence

Cs-sour Ore, 5 20 SIms etcept to a

few tress where nreraoI is ICC Mms

4-

- Fe 5 Ones - dashed where tpprOslssafe

* Eoerhgooke epSenter

Figure 2-2. Contours showing changes in elevation, 1935 to 1963.

34
CANE SPRtNG6

5 0 5 :0 5 20

SCALE OF MSES

L0ntouSnrn !!f:mete[s -O

° 0 -

(

0MOAPA

- _)

-

/

::r

k" /

- - (

r 000CR DAM Dtrtoi

0BOUL

* (4ft

Jll

/

I

/ /

020 h-°

N

////

/

0

0

BEAVER DAM CEEK

990

N ))\J 6O

EXPLAN1ON

-- \ \

-__------_----- cnonge -in- e/evoricq coo/ours oused

610 on speoio/ odjustrneors o' 963 ce/too/nO

\

°0 Cotoçe -.n eIevotpOn CO/tOUrS b0000 on

copp/errnenrary odjusroreol of 964.

+ 40 0000/es reboneds

N

- 60 ( Indicates RubsiOtnue)

0

0

Coetour flretUCi 20 Mms rcepr rn a

N/EbB 05eARc/s/ new amos where IrferuOl 5 /00 Mon

- too/I Ones (dnhed where oppron*ote

* Eomrhquake e7icenrrnr

Figure 2-3. Contours showing changes in elevation, 1949 to 1963.

35
Effect of Subsidence or Rebound

Upon Reservoir Capacity

The precise leveling of 1935 known as Hoover Dam net

"Powerhouse Datum" has been used as a base for all

topographic and hydrographic surveys of the reservoir

area and for tabulations of reservoir area and capacity

in 1940-41, 1948-49, and 1963-64. The computations

of area and capacity do not include adjustments for

any changes in elevations of the basic reference marks

as documented by any of the releveled lines since

1935.

Table 2-2 shows the changes that have occurred at 17

of the Hoover Dam bench marks. Subsidence averaged

118 mm since 1935 at the dam as contrasted to a

subsidence range of 60 to 200 mm in the Boulder

Basin, Boulder Canyon and Virgin Basin portions of

the reservoir indicated in Figure 2-2. More than 80

percent of the reservoir capacity at elevation 1150 feet

is contained in Boulder Basin, Boulder Canyon, and

Virgin Basin. This percentage increases with declining

lake levels. An average rebound of 8 mm was noted for

the 17 bench marks at the dam since 1949 as compared

to the 20- to 80-mm range of rebound indicated in

Figure 2-3 for this portion of the reservoir.

The change in reservoir capacity since 1935, that

occurred owing to subsidence or rebound of the

reservoir basin, is considered insignificant because the

changes in elevation representing most of the reservoir

bottom have been relatively small and in the same

direction as the Hoover Dam change in elevation.

Furthermore, a 200-mm change in elevation (0.66

foot), which is about the maximum divergence

indicated by the 1963 relevel data, is within the

accuracy limits of the survey methods used to

determine the 10-foot reservoir contours.

Table 2-2

HOOVER DAM

AVERAGE SUBSIDENCE IN MILLIMETERS

(Special Adjustment)

1935-63; 1949-63

Bench marks

at

Hoover Dam

1935

elevation

meters

1949

elevation

meters

1963

elevation

meters

1935-63

difference

millimeters

1949-63

difference

millimeters

E 174 375.8266 375.6992 375.705 -122 +6

K 174 377.0976 376.9676 376.974 -124 +6

F 174 375.8028 375.6735 375.683 -120 +9

J 174 375.8240 375.7163 375.733 -91 +17

G 174 375.7931 375.6700 375.682 -111 +12

H 174 375.8119 375.6808 375.693 -119 +12

Q135 375.8013 375.6720 375.686 -115 +14

R 135 375.7964 375.6776 375.692 -104 +14

U 135 375.8412 375.7362 375.756 -85 +20

S135 375.8022 375.6796 375.692 -110 +12

T135 375.8292 375.7122 375.723 -106 +11

Z 135 205.8365 205.7015 205.702 -134 0

L 174 205.8249 205.6993 205.697 -128 -2

M 174 205.8367 205.7009 205.701 -136 0

Y 135 205.8264 205.7036 205.705 -121 +1

0174 214.8902 214.7470 214.749 -141 +2

C 136 214.8942 214.7554 214.758 -136 +3

1935-63 average subsidence 118 mm.

1 949-63aveebound=8rnm.

36
PART 3-HYDROGRAPHIC SURVEY

Objective

The objective of the hydrographic survey was to obtain

the latest data on the reservoir contour areas at 10-foot

vertical intervals below water surface elevation of 1229

feet. These data were used to determine the new area

and capacity of the reservoir. They also provided

information on the volume and distribution of the

sediment deposits and the extent of other reservoir

changes determined by comparing with data from

previous surveys (see Part 5).

Field work for the Lake Mead survey began on July 9,

1963, in the north Overton Arm area and was

completed on October 14, 1964. The location and

numbering system of the various basins are shown in

Figure 3-1. Aerial photographs were taken during the

fall of 1963 when the lake was at elevation 1150 feet.

Sonar soundings were made from a launch to

determine lake depths for the impounded reservoir

area. Photogrammetric and standard surveying methods

were used for the Overton Arm, Grand Bay, and Pierce

Basin to determine the increased volume or the

movement of sediment deposits that have occurred iii

the area above elevation 1150 feet since the 1948-49

survey. Lower Granite Gorge was surveyed by

rerunning the same cross-section locations used in the

1948-49 survey. The remaining areas above the

1150-foot level where no changes had taken place were

not resurveyed.

Computations of the new Lake Mead areas and

capacities were made and the results tabulated (Tables

3-5 and 3-6) using the 1963-64 data. These updated

capacity tables are important to the efficient planning

and scheduling operations of Lake Mead, the largest

reservoir on the Lower Colorado River System.

The 1963-64 survey which determined the volume and

distribution of sediments is a valuable supplement to

the 1948-49 comprehensive survey of Lake Mead. The

rate of sediment inflow to Lake Mead was substantially

changed after Glen Canyon Dam was closed in March

1963. Much of the sediment that heretofore deposited

in Lake Mead is now being captured by Lake Powell

(formed by Glen Canyon Dam).

Vertical Control

The reservoir forebay elevation gage at Hoover Dam

was the principal reference used in establishing vertical

control for the hydrographic surveys. This gage,

included in the relevel net, was found to check the

graphic record at the dam within 0.01 foot.

Additional tidal and staff gages shown in Figure 3-2

were established on the perimeter of Lake Mead. These

were used to determine the lake surface elevation and

possible differences because of seiches, tides, wind, and

slope during the hydrographic survey. The gages were

located at Boulder Wash, Nevada; Hualapai Wash,

Arizona; Center Point, Arizona; Overton Arm, Nevada;

Echo Bay, Nevada; and Detrital Wash, Arizona.

Vertical control for each cross section in the Lower

Granite Gorge area was established by a combination

of differential and trigonometric levels that were used

with the established elevations of recoverable bench

marks listed in a supplemental base data report.31

Horizontal Control

After reviewing the results of previous survey work, it

was decided to use, wherever practicable, the same

triangulation stations established during the 1948-49

survey for the horizontal control in the 1963-64 Lake

Mead survey. Most stations were located and the others

recovered or reestablished by third order triangulation.

The station locations were plotted on boat sheets to

control boat lines and to sight fixes (positions) as

needed. The triangulation nets established during the

1948-49 survey for the various basins in Lake Mead are

shown in the Geological Survey report.32 Tables

listing the geographic positions of the triangulation

stations are given in a supplemental base data

report.33

Triangulation Work

Fifty-two stations were premarked for aerial

photography with 15-foot white crosses, most of which

were centered over existing triangulation stations. The

map (scale 1 :500,000) in Figure 3-3 shows where these

stations were located and Table 3-1 lists their

coordinates in the East Zone, Nevada Grid. Ten of the

stations were in areas where control was not available

and were located by third order triangulation. Many of

the triangulation station poles set up in the 1948-49

survey were still in place and served as sighting points

for this later survey. Triangulation stations close to the

shoreline were excellent targets for sighting by sextant.

The boat sounding positions were plotted directly from

the sextant sightings on the triangulation stations.

' U.S. Department of the Interior, "Supplemental Base Data for Lake Mead Comprehensive Survey of 1948-49,"

Report, 121 p, July 1954.

3-2 Geological Survey, "Comprehensive Survey of Sedimentation in Lake Mead, 1948-49," Professional Paper 295,

254 p. 1960.

Same as footnote 3-1 -

37

Er

36 C

05

3600

FIGURE 3-1

39

H.

25 20 4
U4° 45' 30' 5 1J4° 00'

LAKE MEAD NEVADA -ARIZONA

3____ __ __ __

T.G.

-

Overton Arm

Ed o Bay

T.S.

15' ________________________ ________________________

Center

Boulder Pa I n t

Wash TS

TG..

36°OO'

_________

Defrital

Wa $ h

T.G. Wash

_____________________ ______________________ ______________________ -

COAST AND GEODETIC SURVEY

TIDE GAGE SKETCH

JULY- 963

SCALE 1:500,000

L EG END

TIDE GAGE T.G. 0

TIDE STAFF T.S. 0

41

FIGURE 3-2
LAKE MEAD NEVADA - -ARIZONA

114° 45 30

5'

BOULDER

CITY

15

CONTROL FOR AERIAL PHOTOGRAPHY

-1963-

JUNE I TO DEC. 31

SCALE - 1:500,000

LEGEND

PREMARKED HORIZONTAL CONTROL

STATIONS FOR AERIAL PHOTOGRAPHY

US. HIGHWA'Y 93 & 466

Fl

Il4°O

42

....• . -

j.._ ....... - - -
Table 3-1

HORIZONTAL CONTROL STATIONS USED FOR AERIAL PHOTOGRAPHY

______ East Zone Nevada Grid

Station X Coordinate Y Coordinate

N-2 731,260.56 474,664.10

N-3 732,454.40 485,044.56

N-5B 714,228.42 501,339.82

Vegas Wash No.1 706,504.08 507,715.08

Vegas Wash No. 2 734,586.20 499,181.29

N-8A 744,704.57 499,778.49

N-bA 757,91221 502,749.83

N-12 775,955.36 506,687.62

N-34 839,289.87 516,542.61

N-39 844,543.09 542,381.18

N-54 848,978.46 563,749.23

N-55A 843,936.26 567,099.26

N-63 843,858.40 586,968.45

N-68 850,426.05 600,773.93

N-75 860,543.75 618,203.44

N-91 841,961.25 641,162.24

N-92 845,423.92 648,000.85

Virgin Arm Substation 865,672.15 657,462.32

N-80D 864,000.98 630,643.38

N8OC 866,439.32 628,557.93

N-70 869,426.68 601,888.48

N-67 863,467.56 595,413.55

N-62 856,316.10 577,446.93

N-45 856,887.43 550,873.34

N-38 851,542.34 530,298.91

N-107 867,488.88 505,790.78

N-112 880,561.47 484,340.30

N-126 907,263.19 464,749.42

N-135 925,715.51 475,335.72

N-143 936,213.05 510,484.84

A-89 963,672.84 531,288.41

Grand Wash No. 2 964,843.52 549,882.36

A-90 965,895.60 530,427.31

A-115 970,682.85 501,466.24

Al 16 968,847.29 502,444.65

A-97 968,334.35 521,531.44

A-73 947,955.08 523,391.24

A-65 937,412.80 491,939.99

A-58 924,599.76 466,720.18

A-47 902,857.96 462,650.55

A-36 869,435.46 473,956.34

A-32 861,136.74 500,466.29

A-27A 844,936.62 497,891.43

A-26C 841.53126 492,622.22

A-25DA 829,792.19 474,607.37

A-24 814,662.89 498,639.88

A-20 798,433.88 510,696.88

indian Canyon 776,126.30 500,888.30

A-2 754,217.40 477,300.86

Rough Substation 741,350.80 460,835.52

Rich 734,719.55 458,875.62

Scanlon Hill 926,900.35 492,990.30

43
The Nevada State system of plane coordinates was

extended a short distance into Arizona by

computations for the stations in Grand Bay and Pierce

Basin. These computations were made by the Coast

and Geodetic Office, Washington, D.C. Some of the

stations were used for control of aerial photography in

the upper Overton Arm, Grand Bay, and Pierce Basin

where such photography was the supplemental

technique necessary to delineate the 10-foot contours

between elevations of 1150 and 1 230 feet.

River range sections established in the 1948-49 survey

but not recoverable in Lower Granite Gorge were

relocated by traverse using a theodolite and a subtense

bar. Traverse angles were measured by closing the

horizon with a 6-second rejection and the subtense bar

intercept measured four times with a 4-second

rejection limit. When only one end of an old section

was recoverable, direction was based on the compass

azimuth listed in the supplemental base data report.34

Azimuth checks at the beginning and end of traverses

were made using a solar attachment with the

theodolite. Each traverse was adjusted to the 1948-49

stadia traverse.

Hydrographic Survey Procedures

The Lake Mead Reservoir area was divided into two

areas each surveyed by different techniques. Longitude

1130 57' was the dividing line of the area between the

main part of the lake and lower Granite Gorge. This

was the same delineation used in the 1948-49 survey.

The main part of the lake was surveyed using

echo-sounding equipment. This part, identified as

"Lake Mead area west of Longitude 113° 57',"

extends from Pierce Ferry for about 65 miles to

Hoover Dam and includes the Overton Arm. It is

characterized by a series or chain of wide basins

connected by short narrow canyon sections.

The Lower Granite Gorge area was surveyed by

conventional procedures using a manually operated

sounding machine to resurvey the submerged portion

of the cross sections. The gorge in the upper section of

the lake is a deep rugged canyon about 40 miles long.

It extends upstream from a point just above Pierce

Ferry to Bridge Canyon.

Lake Mead Area West of

Longitude 1 1 57'

Eleven reservoir sheets were laid out for mapping the

Lake Mead area below elevation 1150 feet. The

Ibid.

geographic limits of each sheet are given in the

descriptive reports of the Coast and Geodetic Survey

and their latitudes and longitudes listed in Table 3-2.

Two supplemental reservoir Sheets, 7 and 11, were laid

out for mapping the Overton Arm, Grand Bay, and

Pierce Basin above elevation 1150 feet, the only areas

showing any significant change in sediment deposits.

These sheets cover about the same areas in Sheets 7

and 11 below 1150 feet. Figure 3-4 shows a layout of

the 1963-64 survey sheets superimposed on the layout

of the Soil Conservation Service 5-minute quadrangle

sheets for the 1935 survey.

The latitudes and longitudes in Table 3-2 are not, in

every case, the same as the common or match lines

used by the Bureau of Reclamation for planimetry of

sheet and basin contour areas. Some basin areas

included more than one smooth sheet. In some cases it

was necessary to use the original 1935 Soil

Conservation Survey contour areas above the

1150-foot elevation to complete the elevation-area

relationship for the whole reservoir. In these cases it

was necessary to planimeter the areas between the

previously established basin boundaries and the

5-minute quadrangle limits of the original 1935 survey.

Water depths were found using sonar equipment and

using some manual leadline soundings in the submerged

portions. In the exposed portions of the reservoir,

elevations were determined by standard land surveying

procedures.

Two fathometers, one operating on 200 kc and the

other on 20 kc, were installed in each vessel. The

200-kc fathometer operating in the foot mode was

primarily used to obtain soundings for the entire

survey. In areas having an irregular bottom both echo

sounders were operated with the 20-kc instrument set

in the fathom mode so the fathometer operator could

determine the correct range of the 200-kc instrument.

Both fathometers were operated in the foot mode on

crosslines. Here the 200-kc fathometer would sound

from the top of the sediments; however, the 20-kc

echo sounder did not penetrate the silt as expected.

A variable frequency power supply unit was furnished

for experimental purposes consisting of an inverter,

driven by a variable 12-volt direct-current supply

capable of delivering a 115-volt alternating current at a

frequency range of 57 to 63 cps. The speed of the

stylus drive motor could be controlled as desired by

changing the input power frequency to the fathometer

recorder. The operator was able to choose a power

frequency which gave the least overall correction for

44

-
Table 3-2

1963-64 LAKE MEAD SHEETS

Geographic Description

U.S.B.R. USC&GS Ljjtitude j

__________

Longitude

Sheet Field No. I From I To

Inset 1 12-4-63 36°06'N 36°08'N 114°49'W 114°53'W

Inset 1 12-4-63 36°01'N 36°10'N 114°42'W 114°50'W

Inset 2 12-5-64 36°05'N 36°10'N 114°32'W 114°44'W

Inset 3 12-6-63 36°03'N 36°11'N 114°25'W 114°33'W

Inset 4 12-5-63 36°05'N '36°13'N 114°22'W 114°27'W

Inset 5 12-3-63 36°13'N 36°22'N 114°21'W 114°27'W

Inset 6 12-2-63 36°20'N 36°29'N 114°19'W 114°25'W

Inset 7 12-1-63 36°26'N 36°35'N 114°19'W 114°25'W

Supp. 7 T-12569A 36°26'OO"N 36°35'OO"N 114°19'OO"W 114°25'OO"W

Supp. 8 12-1-64 36°02'N 36°09'N 114°17'W 114°22'W

Supp. 9 12-2-64 36°00'N 36°05'N 114°09.15'W 114°21'W

Supp. 1 0 12-3-64 36°00.70'N 36°10'N 114°04'W 114°11'W

Supp. 1 1 12-4-64 36°07'N 36°15'N 113°57'W 114°05'W

Supp. 1 1 *T12573A 36°06'30'N 36°15'OO"N 1 13°57'OO"W 1 14°05'OO"W

* Shoreline Manuscript number.

1 U.S. Coast and Geodetic Survey Descriptive Report H-8776 states that the north limit of this sheet is at latitude

36°13'N. A Government memorandum dated 17 May 1965, for Contour Sheet C&GS HFP-1 2-5-63, states that the

north limit of this sheet is at latitude 36°13'30"N.

45
C)

-n

C)

C

m

LAKE ME.AD SURVEY

963-64

RESERVOIR SHEET INDEX NSF

SCSLE 250000

14 22 31

-

LEGEND

-

S 52569 © SHEET NO 963 -64 SURVEY

- 2-5-64 U 5 COAST S GEODETIC SURVEY 1963-64 SHEET LAYOUT IDENTIF CATION

13 1935 U S SOL CONSERVATION SERVICE 5 MINUTE QUAÔRSNGLE SVEETS

6 24 33

- 2-2 63

25

- 12-464 -

IX I 12 3-63 42

12 I 64

4s I
the range to be sounded. The change in recorded

soundings was proportional to any change made in the

power frequency. The largest change in the recorded

soundings occurred at the greater water depths. The

effects of temperature were also considered during the

experimental tests. The Lake Mead curve relating

temperature and depth showed a sharp bend between

50 and 75 feet. Changing the power supply to consider

temperature effects would not reduce the corrections

over the entire range of soundings. After running

several bar checks, 60 cps was the operating frequency

found to yield the most accurate results; therefore,

standard inverters were used.

In traversing areas of irregular bottom, the fathometer

operator occasionally was unable to switch depth scales

at a rate equal to the rate of substantial change in

bottom conditions; therefore, soundings were made

with the 20-kc instrument set in fathom mode. For

these situations, a notation was entered in the field

books (sounding volumes) that the fathom scale was

used in the soundings. Velocity corrections for these

soundings were determined and also entered in the

sounding volumes. Echo-sounding corrections applied

to the fathometer soundings were determined from

daily bar checks and temperature observations taken at

2-week intervals.

The echo.sounding equipment provided continuous

soundings along designated lines or courses. Soundings

were made along parallel lines spaced about 300 yards

apart. The divergence at the ends of lines in radial

patterns was generally less than 400 yards. Boat lines

were controlled by visual three-point fixes on the

triangulation stations. Additional topographic signals

were located by ground survey methods. In zones

where hydrography was run with no available fixes,

boat sounding lines were controlled by transit sighting

and stadia from shore.

Two sets of map sheets of the lake were prepared for

the survey. One set, called boat sheets, was used for

delineating the sounding lines to be run and for field

plotting the boat courses actually traveled. The other

set, called smooth sheets which conform to more rigid

mapping standards, was used for the fsl smooth

plotting of the boat courses, entry of the bottom

elevations as computed from the echo-sounding

recorders, and the delineation of contour lines

indicated by the sounding data. In some cases the

normal procedure of locating positions on the boat

sheet using prominent shoreline features was not

followed although a position was given at the end of

the lines and a reference, "see boat sheets," was noted

in the sounding volumes. The lines were plotted on the

boat sheets according to time and course; "see boat

sheets" positions were not used for hydrographic

contouring of smooth sheets. In all the coves in which

hydrography was run with no available fixes, sounding

lines were run by "dead reckoning." Dead reckoning is

a procedure by which the position of a vessel at any

instant is determined by applying the vessel's course

from the last known position using the course heading

in degrees, vessel speed in mph or knots, and the time

traveled from the last known position.

When the survey of an area on one sheet was

completed, the depths sounded along lines common to

adjacent sheets were compared. Generally, agreement

was good and the contours could be satisfactorily

drawn at common lines.

Comparison was also made with charts from the Coast

and Geodetic Survey of 1955 revised in 1961. All reefs

and rocks indicated on the charts were plotted on an

overlay of the boat sheets with their respective

elevations marked in red. For each rock or reef the

charted position, charted elevations, new elevations

found by this survey, and a recommendation of

charting or changes were listed in the descriptive report

written for each of the 11 respective area divisions.

Fixed lights, reef markers, and other aids to navigation

were investigated with regard to location, condition,

elevation, and adequacy. The results and pertinent

comments are given in the descriptive reports of the

U.S. Coast and Geodetic Survey.

Lower Granite Gorge Area

To run the survey of the Lower Granite Gorge area, a

six-man team was flown (Figure 3-5) into the gorge on

September 23, 1963. A base Camp No. 1 was

established in the gorge at River Mile 267 and later a

Camp No. 2 was set up at River Mile 247.

The field work for the 1963-64 survey included

reprofiling the same 174 river sections above the head

of Pierce Basin used in the 1948-49 survey. Of these

sections, however, 148 were recoverable and the other

26 had to be reestablished.

To reprofile the cross sections, three men were

required, two aboard a 14-foot aluminum skiff

equipped with a tag line and one ashore to keep the

skiff on range. Horizontal distances between sounding

points along each section were measured with a

theodolite and stadia rod. Soundings were taken using

a tag line that was run through a registering sheave

calibrated in fathoms and attached to a standard Coast

and Geodetic Survey hand-sounding machine mounted

47
-

-.

Figure 3-5. Because of the low lake levels prevailing in 1963, surface watercraft could not

be used for traveling to the Pierce Ferry Basin delta area. Above are two views of the

amphibian used to transport men and equipment to the inaccessible areas in Lower

Granite Gorge of the Colorado River. Top Photo P45-D-68117, bottom Photo

P45-D-681 18

48
in the skiff. At the free end of the tag line a standard

mud anchor was attached with a snap-type clip. The

anchor was firmly seated on the beach on range and

the skiff brought up to shore. The sheave was zeroed

and the soundings were taken at 3-fathom (18-foot)

intervals. Because of the strong currents prevailing, it

was necessary to back the skiff across the river using

the engines in reverse to control alinement and keep on

range. Stadia methods (Figure 3-6) were used to

establish the elevation of the water surface, locate

water's edge, and check tag line distances.

Figure 3-6. Example of using stadia to establish

reservoir water's edge. Photo P45-D-681 19

The crosses marking each relocated range were

repainted white. White crosses were also painted at the

ends of each range reestablished during the 1963-64

survey.

Determination of Contour Areas

Contour areas were determined by personnel from the

Regional Office, Bureau of Reclamation, Boulder City,

Nevada. The areas at 10-foot contours below elevation

1150 feet for the reservoir lake portion, excluding

Lower Granite Gorge, were determined from the

topographic sheets of the 1963-64 survey.

Supplemental topographic sheets of this survey and

portions of the 5-minute quandrangle sheets of the

1935 Soil Conservation Service survey were used to

trace contour areas above elevation 1150 feet.

The subbasin boundary lines were at different latitudes

and longitudes from the common or match lines of the

1963-64 topographic sheets. It became necessary,

therefore, to divide the planimetering of certain

topographic sheets at subbasin boundaries so the

proper areas could be totaled for the individual

subbasins. It was also necessary to do this on various

portions of the 1935 5-minute quadrangle sheets.

Each 10-foot contour on the topographic sheets was

planimetered a minimum of three runs. Averages were

taken of the recorded differences between beginning

and end readings for each run. These averages were

multiplied by the acreage factor per planimeter unit to

obtain the contour areas.

The percentage of difference between the runs for each

contour was obtained and used as a guide in selecting

contours to be replanimetered as a check. Using this

guideline, a minimum of two 10-foot contours per

topographic sheet having the greatest percentage of

difference was selected.

All contours encompassing an area greater than 25

acres, with a maximum difference of 1 percent

between runs, were replanimetered as a check. For

contour areas of 25 acres or less, a 2 percent difference

between runs was allowed before making a smiliar

check. Examining the actual percentage of difference

in a representative number of elevations showed an

average of 0.6 of 1 percent variation between runs on

the planimeter work for this survey. The replanimeter

work was always done by a different planimeter

operator.

The relation between elevation and area was plotted

for each topographic sheet. When a marked deviation

from the general trend of this relationship was noted, a

planimeter check was made of the contour area at the

elevation showing the divergence. In some instances,

planimetric checks were also made of the contour areas

at the 10-foot elevations above and below the one of

maximum deviation.

From results of the two different types of planimeter

checks described, necessary adjustments to the contour

areas were made for the affected elevations.

49
Some topographic sheets had areas where the 10-foot

contours were too closely spaced for accurate

planimetering. Here, contour areas were determined by

interpolating between the areas planimetered at

elevations of greater contour intervals. This method

was used for the area just upstream from Hoover Dam

on Soil Conservation Service 5-minute quadrangle

Sheet 8. Each 50-foot contour interval was

planimetered and the intervening 10-foot contour areas

determined by interpolation. The same method was

used on that portion of Soil Conservation Service

quadrangle Sheet 11-12 used for Boulder Canyon Basin

X+Y, on which only the contours at elevations 1100,

1200, and 1300 feet were planimetered. In several

instances this method was also used as a check on fully

planimetered areas.

Contour areas by 5-minute quadrangle sheets as

determined in the 1935 survey are given in Table 3-3.

The full table is included for future reference. The

1935 data compiled by the Soil Conservation Service

were used for areas above elevation 1150 feet except

where areas were resurveyed in 1948-49. Certain

corrections have been made and explanatory footnotes

added to Table 3-3. The corrections apply to the 1935

survey results and include the addition of contour areas

omitted and the correction of contour areas

erroneously included. The Soil Conservation Service

was consulted before corrections were made.

The Lower Granite Gorge portion of the reservoir was

covered by 174 cross sections from the 1963-64

survey. Data from the 1948-49 survey were used to

extend some of these sections to higher elevations.

Contour areas for the Lower Granite Gorge were

computed using the average width times the length of

the reach for each 10-foot vertical interval. This was

done for each area between the 174 river sections

covering the entire length of Lower Granite Gorge.

Areas between reaches at the same 10-foot elevation

were then added to arrive at the total 10-foot contour

areas of the gorge. Side canyon areas along Lower

Granite Gorge were determined by planimetering

100-foot contour areas and interpolating values for

each 10-foot contour.

Comparative contour areas for the 1935, 1948-49, and

1963-64 surveys are listed in Table 3-4. The total

contour areas at 10-foot elevation intervals for each

basin are listed in Table 3-5 for the 1963-64 survey.

Computation of Reservoir

Capacities

The capacities of the individual basins and of the total

reservoir as listed in Table 3-6 were computed using the

data of the areas planimetered. The computations were

made by personnel of the Division of Data Processing,

Office of Chief Engineer, Bureau of Reclamation,

Denver, Colorado. Area and capacity curves are shown

in Figure 3-7. Total individual basin capacities are

listed in Table 3-7 for each of the surveys run in 1935,

1948-49, and 1963-64.

A computer program was written to interpolate the

total and individual basin area values at 1-foot

elevation intervals by the Lagrangian Method applied

to the values in Table 3-5. Using these interpolated area

values, total and individual basin capacities were, in

turn, computed also at 1-foot elevation intervals by the

average end-area method. A study of the computer

output results shows that exact checks using a desk

calculator cannot always be obtained of the capacity

between 10-foot elevation intervals. These checks

cannot be obtained because of the accumulative and

rounding-off effects that occur in the computer

processing of the values at the 1-foot elevation

intervals.

The 1963-64 survey indicates that the total reservoir

volume below elevation 1229 feet decreased 1,292,000

acre-feet since the 1948-49 survey. Changes in capacity

of the individual subbasins below elevation 1229 feet

are listed in acre-feet in table on following page.

Reasons for the changes listed in the table on following

page are discussed in Part 5.

Miscellaneous Hydrologic Data

The monthly evaporation losses and end of the month

surface areas are recorded in the graph of Figure 3-8.

The recorded average monthly Hoover Dam releases

and available contents since 1935 are plotted in Figure

3-9.

50
CHANGES IN CAPACITY OF INDIVIDUAL SUBBASINS IN ACRE-FEET

Basin -

'1935 to 1948-49 2194849 to 1963-64 Totals

Boulder Basin [ 1 -81,700 r 1

Boulder Canyon I-437,000 I

-54,000 I 850,7O0 1

Virgin Basin L J -278,000 L J

Temple Bar Area r

459 000] -87,000 1

l637IJO Virgin Canyon [ , _yj [ j

Gregg Basin -114,000 -206,100 320,100

Grand Bay -97,000 -269,800 366,700

Pierce Basin -144,000 -222,700 366,700

Lower Granite Gorge -541,000 +1 5,800 525,200

Overton Arm -33,900 -91,900 125,800

Total -1,425,900 -1,293,100 2,718,900

Taken from Table 6 of report, "Comprehensive Survey of Sedimentation in Lake Mead. 1948-49," Professional

Paper 295, Geological Survey, 1960.

2 See Table 5-1 of this report.

Total in Boulder Basin, Boulder Canyon, and Virgin Basin.

Total in Temple Bar Area and Virgin Canyon.
Table 3-3

SOIL CONSERVATION SERVICE

1935 LAKE MEAD SURVEY

10-foot Contour Areas in Acres

Elevation (feet)

Sheet

No. 650 _____ 660 670 680 690

1,2,3

4 73.82 136.86

5 128.00 190.16 423.44

6, 7 365.79 663.69

8 227.62 734.97 913.19 1,178.06

9 3.98 23.47 134.02

10

11, 12

14

15

16

17

18

19

20, 21

22

23

24

25

26

27

28

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

Totals 227.62 86695 1,566.43 2,536.07

52
Table 3-3-Continued

SOIL CONSERVATION SERVICE

1935 LAKE MEAD SURVEY

________

10-foot Contour Areas in Acres

_____ Elevation (feet)

Sheet

________________ ______ ______

No. 700 710 720 730 740

1,2,3

______

4 205.08 24155 277.71 313.89 358.26

5 460.82 519.06 582.59 652.13 715.86

6,7 1,106.57 1,388.97 1,643.85 1,813.78 1,990.57

8 1,326.15 1,400.32 1,466.88 1,525.43 1,578.10

9 386.26 457.04 520.57 582.76 640.55

10

11, 12 36.54 123.61 275.83 382.95 610.64

14

15

16

17

18

19 288.62

20, 21

22

23

24

25

26

27 2.59

28

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

Totals 3,521.42 4,130.55 4,767.43 5,270.94 6,185.19

53
Table 3-3-Continued

SOIL CONSERVATION SERVICE

1935 LAKE MEAD SURVEY

10-foot Contour Areas in Acres

Elevation (feet)

Sheet

No. 750 760 770 780 790

1,2,3

4 400.65 464.69 511.99 552.07 589.10

5 769.55 813.95 858.84 913.62 998.06

6, 7 2,166.27 2,426.19 2,662.51 2,828.78 2,978.71

8 1,621.83 1,677.21 1,734.17 1,790.08 1,852.62

9 678.27 717.17 744.17 768.88 795.09

10

11,12 874.94 993.54 1,099.84 1,254.24 1,423.30

14

15

16

17

18

19 1,209.54 1,448.00 1,874.06 2,245.40 2,598.30

20, 21

22

23

24

25

26 100.12 264.28

27 345.01 542.03 707.01 839.14 937.80

28

30

31

32

33

34 118.93 174.88 198.54 238.42 274.31

35 12.55 122.87 392.85 670.02

36 83.99

37

38 1.35 13.72 33.29

39

40

41

42

43

44

45

46

47

48

49

50

51

52

Totals 8,184.99 9,270.21 10,515.35 11,937.32 13,498.87

54
Table 3-3-Continued

SOIL CONSERVATION SERVICE

1935 LAKE MEAD SURVEY

10-foot Contour Areas in Acres

Sheet

No.

1,2,3

4

5

6, 7

8

9

10

11,12

14

15

16

17

18

19

20, 21

22

23

24

25

26

27

28

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

Totals

______

Elevation (feet) __________________

800 _____

810 820 830

626.17 677.03 729.08 781.26

1,142.80 1,288.78 1,422.75 1,577.07

3,123.76 3,273.92 3,407.43 3,541.45

1,907.14 1,965.81 2,031.74 2,089.03

824.35 870.59 918.26 956.16

1,553.69 1,650.14 1,728.29 1,809.59

156.42 319.11 499.46 635.73

3,111.04 3,535.90 4,034.76 4,380.65

571.49 834.60 1,008.90 1,076.59

1,026.25 1,117.35 1,214.39 1,373.38

296.51 317.23 336.09 354.05

849.63 974.35 1,103.07 1,226.74

242.09 266.41 303.01 327.31

6.23 76.07

98.91 179.55 303.03 570.55

840

829.21

1,719.89

3,698.77

2,147.32

993.69

1,873.10

798.29

4,637.82

1,172.77

1,516.04

371.30

1,351.58

350.83

227.26

783.64

1.94

15,530.25 17,270.77 19,046.49 20,775.63 22,473.45

55
Table 3-3-Continued

SOIL CONSERVATION SERVICE

1935 LAKE MEAD SURVEY

10-foot Contour Areas in Acres

Elevation (feet)

Sheet

No. 850 860 870

1,2,3

4 881.54 940.89 1,018.71

5 1,862.11 2,006.37 2,197.14

6,7 3,858.52 4,034.51 4,213.40

8 2,211.16 2,279.50 2,341.28

9 1,045.35 1,098.46 1,151.75

10

11,12 1,946.31 2,021.43 2,088.52

14

15

16

17

18 901.72 998.58 1,066.86

19 5,025.43 5,301.62 5,449.20

20, 21

22

23

24

25

26 1,275.23 1,429.11 1,622.95

27 1,804.83 1,998.98 2,159.17

28

30

31

32

33

34 396.61 418.52 453.20

35 1,481.77 1,607.14 1,734.94

36 385.28 407.63 434.12

37 409.61 654.77 851.32

38 1,199.20 1,350.00 1,445.00

39

40 26.87 109.48 202.70

41 16.89 60.72

42

43

44

45

46

47

48

49

50

51

52

Totals 24,711.54 26,673.88 28,490.98

*Areas added to table in 1966. 56

880 890

1,112.06 1,208.88

2,318.83 2,503.16

4,433.06 4,608.68

2,403.01 2,455.15

1,206.41 1,261.06

2,163.52 2,253.84

1,149.05 1,190.72

5,758.26 5,983.84

2.32 72.52

1,771.95 1,912.45

2,327.55 2,517.89

478.99 510.19

1 ,873.57 2,036.65

454.84 498.56

980.47 1,104.45

1,527.15 1,632.56

295.91 419.78

89.90 102.14 *943 *76.34

3.42 41.96

30,359.70 32,390.82
Table 3-3-Continued

SOIL CONSERVATION SERVICE

1935 LAKE MEAD SURVEY

10-foot Contour Areas in Acres

Elevation (feet) __________________ _____________

Sheet

________________

No. 900 910 920 930 940

1,2,3

4 1,321.97 1,448.63 1,586.39 1,727.66 1,865.56

5 2,710.80 2,940.59 3,099.03 3,235.06 3,423.35

6, 7 4,727.52 4,918.80 5,094.28 5,276.14 5,485.66

8 2,512.82 2,587.73 2,643.16 2,690.08 2,757.98

9 1,318.28 1,385.41 1,455.04 1,520.45 1,57876

10

11,12 2,338.08 2,45698 2,533.51 2,620.56 2,689.11

14

15

16

17

18 1,225.00 1,313.95 1,360.66 1,441.79 1,513.57

19 6,203.50 6,445.21 6,688.94 6,901.47 7,134.02

20, 21

22

23

24

25 149.19 223.52 358.91 503.04 720.49

26 2,057.28 2,228.68 2,381.62 2,528.41 2,672.27

27 2,695.22 2,938.69 3,319.14 3,727.00 3,998.30

28

30

31

32

33

34 544.53 596.56 643.33 700.13 746.46

35 2,206.25 2,372.14 2,513.49 2,669.70 2,828.77

36 509.53 529.81 578.21 605.73 634.70

37 1,244.67 1,366.97 1,470.43 1,584.50 1,689.39

38 1,716.95 1,832.32 1,917.41 2,008.18 2,115.71

39

40 543.63 595.62 647.58 697.13 746.68

41 110.32 118.64 124.23 132.94 138.77

42 *119.42 *148.00 *

169.00 *185.40 *199.50

43 136.07 386.72 590.91 682.71 771.44

44 2.12 53.30 128.05 217.20 278.15

45

46 0.23 0.57

47

48

49

50

51

52

Totals 34,393.15 36,888.27 ______

39,303.32 41,655.51 43,989.21

*Areas added to table in 1966. 57
Table 3-3-Continued

SOIL CONSERVATION SERVICE

1935 LAKE MEAD SURVEY

10-foot Contour Areas in Acres

Elevation (feet)

Sheet

No. 950 960 970 980 990

1,2,3

______

4 1,996.06 2,148.18 2,303.37 2,479.31 2,671.47

5 3,636.03 3,828.17 4,014.64 4,168.55 4,343.44

6,7 5,640.54 5,817.96 5,989.21 6,157.86 6,293.96

8 2,816.12 2,879.64 2,936.30 2,999.47 3,061.14

9 1,638.30 1,710.65 1,78L38 1,850.18 1,906.19

10

11, 12 2,772.36 2,870.26 2,958.63 3,078.72 3,182.09

14

15

16

17

18 1,586.55 1,665.87 1,731.99 1,797.87 1,874.74

19 7,349.67 7,625.83 7,895.94 8,156.88 8,420.82

20, 21 1.45 25.40 49.88

22

23

24 276.33 791.23

25 1,061.88 1,494.60 1,809.28 2,157.99 2,349.73

26 2,835.28 2,995.05 3,156.53 3,320.02 3,489.59

27 4,218.70 4,417.29 4,602.62 4,786.35 4,979.05

28 2.42 4.42 6.93

30

31

32

33

34 808.94 872.27 937.68 987.36 1,045.85

35 3,004.62 3,199.49 3,368.07 3,564.56 3,789.87

36 665.20 714.66 729.93 760.99 816.67

37 1,813.68 1,923.24 2,030.17 2,149.46 2,281.05

38 2,231.71 2,320.91 2,410.33 2,491.38 2,590.77

39

40 809.56 872.43 953.09 1,033.74 1,113.72

41 147.88 153.95 161.00 165.70 172.70

42 *211.34 *224.00 *238.00 *251.50 *266.30

43 841.88 914.47 992.95 1,063.50 1,14059

44 339.63 390.31 436.34 470.50 505.56

45 185.10 221.25

46 110 7.53 3605 55.10 79.66

47 25.99

48 0.45 1.66

49

50

51

52

Totals 46,427.03 49,046.76 51,477.37 54,438.69 57,471.90

*A added to table in 1966. 58
Table 3-3-Continued

SOIL CONSERVATION SERVICE

1935 LAKE MEAD SURVEY

10-foot Contour Areas in Acres

Elevation (feet)

Sheet

No. 1,000 1,010 1,020 1,030 1,040

1, 2,3 14.86 30.26

4 2,876.36 3,078.50 3,299.77 3,519.95 3,739.29

5 4,484.45 4,714.97 4,876.11 5,014.37 5,148.99

6,7 6,435.16 6,603.63 6,769.31 6,940.60 7,123.96

8 3,144.25 3,208.44 3,263.76 3,322.21 3,362.06

9 1,965.44 2,047.38 2,126.50 2,196.21 2,260.09

10

11, 12 3,278.30 3,379.79 3,470.00 3,565.06 3,667.21

14

15

16

17

18 1,946.04 2,040.84 2,114.78 2,202.87 2,283.71

19 8,734.72 9,095.69 9,449.17 9,803.25 10,155.49

20,21 87.21 119.38 162.56 215.53 270.30

22

23

24 1,302.29 1,932.94 2,591.91 3,165.02 3,910.89

25 2,570.31 2,772.34 2,961.07 3,179.57 3,403.60

26 3,655.31 3,842.08 4,021.64 4,234.23 4,449.59

27 5,173.67 5,371.07 5,556.68 5,789.77 5,989.44

28 12.51 17.20 22.74 30.87 37.85

30

31

32

33

34 1,111.17 1,187.05 1,253.00 1,330.22 1,404.44

35 4,013.26 4,248.20 4,368.11 4,582.97 4,765.20

36 830.89 899.44 932.06 975.87 1,017.69

37 2,407.93 2,533.18 2,639.07 2,798.33 2,925.84

38 2,687.41 2,789.50 2,882.70 2,980.04 3,108.18

39

40 1,196.08 1,278.97 1,373.34 1,448.75 1,551.85

41 177.40 184.10 188.61 195.47 200.07

42 281.06 296.00 *310.00 *325.00 *339.50

43 1,213.59 1,320.06 1,403.30 1,505.72 1,601.42

44 541.21 576.36 599.81 634.94 658.34

45 260.28 291.51 317.24 344.67 372.51

46 96.05 111.25 121.40 136.93 147.27

47 43.31 86.24 114.87 148.00 170.12

48 2.46 10.50 33.96 56.35 77.36

49 4.23

50

51

52

Totals 60,528.12 64,036.61 67,223.47 70,657.63 74,176.75

*Area added to table in 1966. 59
Sheet

No.

1,2,3 45

6, 7 89

10

11,12

14

15

16

17

18

19

20, 21

22

23

24

25

26

27

28

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

4,674.38

3,644.20

4,640.20

6,166.09

50.35

1 ,484.37

4,985.08

1,060.91

3,087.23

3,223.87

1,662.98

206.29

354.17

1,752.09

695.60

404.80

162.02

195.96

106.01

26.75

Table 3-3 -Continued

SOIL CONSERVATION SERVICE

1935 LAKE MEAD SURVEY

10-foot Contour Areas in Acres

Elevation (feet)

1,060 1,070

78.07 111.64

4,221.40 4,434.55

5,419.92 5,510.58

7,476.59 7,659.63

3,483.80 3,550.74

2,410.99 2,488.68

3,884.94 3,994.71

2,442.06 2,507.12

10,732.07 11,024.89

429.72 502.59

252.75 738.84

5,444.82 5,993.35

3,918.79 4,185.91

4,823.00 5,030.26

6,350.05 6,558.83

65.88 83.60

1,578.60 1,666.37

5,208.41 5,456.20

1,104.03 1,137.98

3,231.03 3,388.31

3,373.38 3,484.70

1,773.33 1,903.14

210.45 218.19

373.09 396.41

1,879.43 2,044.49

720.51 755.02

434.88 467.40

171.87 184.69

213.19 227.63

123.82 139.73

41.79 54.92

1,080 1,090

0.50

5.16

150.54

4,658.49

5,616.46

7,838.72

3,613.71

2,565.88

1.45

4,105.58

202.77

4,906.59

5,751.28

8,041.90

3,689.97

2,633.59

3.55

4,218.23

1.60

0.46

2,592.42

11,317.31

584.19

1,172.75

6,492.64

4,437.74

5,230.80

6,768.83

102.75

16.94

2.10

3.06

2,680.49

11,600.02

662.61

1,722.36

6,901.62

4,664.09

5,398.99

7,044.24

124.04

30.69

1,756.10

5,672.51

1,177.03

3,529.17

3,560.73

2,033.93

223.38

416.01

2,195.67

778.06

500.28

193.27

237.27

153.47

63.67

Totals 77,894.54 81,872.66 85,906.76 89,759.81

60

50.42

3,978.76

5,290.08

7,286.93

3,416.20

2,331.74

3,767.17

2,368.15

10,469.13

352.61

1,866.13

5,904.95

1,192.57

3,694.68

3,705.63

2,181.23

233.27

448.28

2,343.05

811.33

539.77

201.66

254.35

167.85

87.37

93.91 4.31
Table 3-3-Continued

SOIL CONSERVATION SERVICE

1935 LAKE MEAD SURVEY

10-foot Contour Areas in Acres

Elevation (feet) _______________________________

Sheet

No. 1,100 1,110 1,120 1,130 1,140 _____

1, 2,3 282.61 376.42 464.77 5.48.47 643.40

4 5,187.61 5,505.20 5,834.84 6,154.83 6,352.18

5 5,901.89 6,021.44 6,15335 6,295.57 6,428.69

6, 7 8,234.25 8,384.30 8,549.14 8,714.64 8,890.94

8 3,712.58 3,789.67 3,854.53 3,918.67 3,968.08

9 2,700.62 2,804.81 2,902.72 2,972.54 3,047.79

10 5.24 7.39 9.59 13.57 16.39

11,12 4,332.81 4,463.51 4,561.10 4,661.28 4,764.58

14

15

16 11.85 51.33 109.32 168.77 234.05

17 12.76 42.89 73.69 118.99 163.87

18 2,776.78 2,868.58 2,959.18 3,030.15 3,094.66

19 11,844.38 12,139.95 12,423.55 12,716.82 13,058.49

20,21 748.19 811.45 877.79 951.29 1,046.21

22

23 2,033.08 2,330.58 2,793.97 3,160.35 3,610.58

24 7,252.96 7,566.60 7,885.97 8,220.90 8,524.35

25 4,951.04 5,240.86 5,466.76 5,734.86 5,972.36

26 5,560.53 5,754.98 5,913.35 6,068.29 6,215.72

27 7,265.14 7,472.58 7,667.74 7,890.85 8,097.95

28 149.24 188.35 215.87 248.09 280.73

30

31

32 51.15 7979 131.08 221.42 369.36

33 21.37 53.61 91.26 151.90 204.27

34 1,959.73 2,092.16 2,186.27 2,271.48 2,345.75

35 6,140.54 6,373.59 6,580.00 6,831.93 7,043.52

36 1,281.18 1,353.77 1,380.53 1,446.38 1,467.87

37 3,845.37 4,005.74 4,16230 4,334.36 4,487.78

38 3,876.22 4,017.82 4,125.15 4,243.11 4,347.40

39

40 2,323.58 2,46166 2,604.56 2,775.95 2,948.70

41 239.83 248.89 254.91 263.48 269.21

42 471.14 515.77 55580 611.16 660.19

43 2,492.81 2,692.78 2,854.33 3,039.15 3,215.77

44 833.76 863.79 883.80 918.00 94082

45 578.16 616.69 645.76 682.46 721.62

46 207.26 219.17 228.40 238.21 244.79

47 265.70 290.96 307.79 326.10 338.28

48 178.93 198.87 21212 234.95 251.29

49 103.15 138.01 161.27 201.68 228.62

50 13.14

51

52

Totals 97,833.44 102,043.96 106,082.56 i1O,3865 114,509.40

61
Table 3-3-Continued

SOIL CONSERVATION SERVICE

1935 LAKE MEAD SURVEY

10-foot Contour Areas in Acres

Elevation (feet)

Sheet

No. 1,150 1,160 1,170

_______ ____

1,2,3 738.41 842.71 949.69

4 6,656.44 6,866.41 7,255.04

5 6,572.55 6,724.99 6,879.33

6,7 9,051.65 9,249.34 9,403.96

8 4,037.77 4,100.81 4,163.85

9 3,124.29 3,197.49 3,276.61

10 19.61 24.95 32.11

11,12 4,863.69 4,976.20 5,060.50

14

15

16 283.29 373.42 447.96

17 210.45 281.44 378.74

18 3,161.92 3,255.87 3,321.25

19 13,453.99 13,873.64 14,220.79

20,21 1,153.23 1,308.33 1,478.00

22 85.71 292.01 485.00

23 4,138.85 4,576.17 5,120.53

24 8,864.49 9,161.94 9,533.25

25 6,234.97 6,490.34 6,743.52

26 6,379.44 6,546.21 6,703.58

27 8,320.98 8,550.27 8,781.12

28 344.33 386.83 442.15

30

31 11.94 51.42 76.22

32 548.65 802.34 792.03

33 275.40 373.31 468.42

34 2,450.14 2,543.63 2,631.18

35 7,277.95 7,482.72 7,660.84

36 1,552.06 1,593.39 1,657.41

37 4,655.25 4,832.41 4,970.05

38 4,481.33 4,594.49 4,689.27

39

40 3,121.77 3,302.32 3,470.68

41 278.76 285.17 297.12

42 726.39 803.05 829.91

43 3,432.04 3,635.23 3,851,84

44 985.40 1,015.15 1,054.25

45 769.00 815.00 863.07

46 255.08 261.96 273.40

47 360.06 374.55 397.1 1

48 268.88 280.62 301.33

49 273.12 302.82 337.28

50 28.81 41,51 60.35

51

52

1,180

1,064.19

7,536.44

7,046.18

9,591.52

4,227.09

3,352.59

39.74

5,174.32

536.40

503.18

3,402.83

14,592.83

1,657.03

715.10

5,834.75

9,842.54

6,992.47

6,855.28

9,031.87

494.78

0.85

141.45

886.67

554.03

2,704.71

7,875.84

1,707.50

5,107,24

4,797.82

3,627.55

305.10

887.61

4,054.35

1,080.28

895.13

281.18

412.14

315.15

360.29

79.13

1,190

1,175.46

7,794.41

7,227.96

9,788.03

4,295.15

3,429.93

47.56

5,302.95

630.08

626.53

3,471.79

14,908.13

1,798.93

1,113.48

6,315.91

10,211.79

7,239.45

7,015.10

9,333.50

549.93

2.16

287.64

934.26

652.61

2,796.43

8,083.62

1,812.77

5,264.57

4,877.64

3,787.59

326.60

920.07

4,281.07

1,118.29

942.09

293.82

35.63

335.48

383.11

94.22

Totals 119,447.99 124,470.46 129,358.74 134,565.16 139,505.74

62
Sheet

No. 1,200

Table 3-3--Continued

SOIL CONSERVATION SERVICE

1935 LAKE MEAD SURVEY

10-foot Contour Areas in Acres

Elevation (feet)

1,210 1,220 1,230

1,2,3 1,336.17 1,510.52 1,662.74 1,839.37

4 8,072.43 8,404.44 8,712.67 8,971.24

5 7,403.83 7,617.46 7,809.37 7,997.67

6, 7 9,965.52 10,177.46 10,372.41 10,545.71

8 4,356.23 4,413.15 4,467.30 4,529.01

9 3,502.23 3,596.92 3,679.74 3,762.12

10 54.63 65.87 77.34 86.94

11, 12 5,433.08 5,570.32 5,714.99 5,847.93

14 4.93 328.31

15 17.26 34.38

16 738.54 860.08 1,042.89 1,088.43

17 783.76 903.83 1,010.69 1,130.44

18 3,557.72 3,645.39 3,720.54 3,792.36

19 15,231.37 15,578.01 15,847.51 16,097.32

20,21 1,945.96 2,192.31 2,456.78 2,847.86

22 1,570.88 1,962.07 2,317.85 2,990.30

23 6,723.40 7,114.30 7,460.01 7,806.97

24 10,509.61 10,861.42 11,200.06 11,377.18

25 7,470.78 7,735.76 7,990.28 8,252.33

26 7,159.21 7,323.34 7,470.42 7,605.02

27 9,598.33 9,972.77 10,282.85 10,618.80

28 611.25 668.95 733.85 824.89

30 3.04 94.25 234.79 472.48

31 453.98 681.91 1,007.26 1,150.15

32 1,021.07 1,130.60 1,166.91 1,364.67

33 750.52 852.99 959.97 1,061.72

34 2,884.72 2,992.32 3,064.80 3,156.03

35 8,305.19 8,505.38 8,636.93 8,852.11

36 1,866.68 1,993.61 2,039.23 2,169.10

37 5,424.23 5,594.30 5,735.24 5,886.26

38 4,991.33 5,104.99 5,175.53 5,285.58

39 13.45 38.71 68.57 99.04

40 3,939.46 4,101.59 4,233.45 4,382.74

41 340.99 375.86 408.91 451.55

42 989.07 1,057.42 1,104.30 1,170.77

43 4,502.36 4,693.49 4,876.98 5,085.47

44 1,143.65 1,180.99 1,205.91 1,238.72

45 973.37 1,013.55 1,040.38 1,076.52

46 302.82 320.75 331.55 345.47

47 451.29 480.41 499.79 524.97

48 350.03 374.27 390.47 412.84

49 398.30 431.49 453.61 481.98

50 109.31 127.90 146.54 180.75

51

52

Totals 145,239.79 151 ,320.95 156,833.60 163,223.50

63
Table 3-4

COMPARISON DATA SHOWING AREA, IN THOUSANDS OF ACRES,

AS A FUNCTION OF ELEVATION

1 2 3 4 5 6 7

Original

Elevation 1935 1948-49 1963-64 Column 2 Column 3 Column 2

(FT.MSL) contour contour contour minus minus minus

areas areas areas Column 3 Column 4 Column 4

650 0.0 0.0 0.0 0.0 0.0 0.0

660 0.2 0.0 0.0 -0.2 0.0 -0.2

670 1.0 0.0 0.0 -1.0 0.0 -1.0

680 1.7 0.0 0.0 -1.7 0.0 -1.7

690 2.5 0.0 0.0 -2.5 0.0 -2.5

700 3.5 0.0 0.0 -3.5 0.0 -3.5

710 4.1 0.0 0.0 -4.1 0.0 -4.1

720 4.8 0.0 0.0 -4.8 0.0 -4.8

730 5.5 0.0 0.0 -5.5 0.0 -5.5

740 6.2 0.0 2.1 -6.2 +2.1 -4.1

750 8.1 4.3 4.2 -3.8 -0.1 -3.9

760 9.2 6.0 5.2 -3.2 -0.8 -4.0

770 10.5 7.1 6.2 -3.4 -0.9 -4.3

780 11.9 8.7 7.2 -3.2 -1.5 -4.7

790 13.5 11.8 8.7 -1.7 -3.1 -4.8

800 15.5 13.8 12.3 -1.7 -1.5 -3.2

810 17.2 15.8 14.5 -1.4 -1.3 -2.7

820 19.0 18.0 16.2 -1.0 -1.8 -2.8

830 20.7 19.8 17.7 -0.9 -2.1 -3.0

840 22.5 21.4 19.6 -1.1 -1.8 -2.9

850 24.7 23.1 21.5 -1.6 -1.6 -3.2

860 26.6 24.8 23.3 -1.8 -1.5 -3.3

870 28.5 26.6 24.9 -1.9 -1.7 -3.6

880 30.4 28.8 26.3 -1.6 -2.5 -4.1

890 32.4 30.8 27.9 -1.6 -2.9 -4.5

900 34.4 33.0 29.9 -1.4 -3.1 -4.5

910 36.9 35.2 32.4 -1.7 -2.8 -4.5

920 39.3 37.4 34.6 -1.9 -2.8 -4.7

930 41.7 39.6 36.9 -2.1 -2.7 -4.8

940 44.0 41.9 39.1 -2.1 -2.8 -4.9

950 46.4 44.2 41.6 -2.2 -2.6 -4.8

960 49.0 46.8 44.2 -2.2 -2.6 -4.8

970 51.5 49.1 46.7 -2.4 -2.4 -4.8

980 54.4 51.9 49.1 -2.5 -2.8 -5.3

990 57.5 55.0 51.6 -2.5 -3.4 -5.9

1000 60.5 58.1 54.8 -2.4 -3.3 -5.7

1010 64.0 61.5 58.1 -2.5 -3.4 -5.9

1020 67.2 64.6 61.2 --2.6 -3.4 -6.0

1030 70.7 68.0 64.3 -2.7 -3.7 -6.4

1040 74.2 71.6 67.5 -2.6 -4.1 -6.7

64
Table 3-4-Continued

COMPARISON DATA SHOWING AREA, IN THOUSANDS OF ACRES,

AS A FUNCTION OF ELEVATION

1 2 3 4 5 6 7

Original

Elevation 1935 1948-49 1963-64 Column 2 Column 3 Column 2

(FT.MSL) contour contour contour minus minus minus

areas areas areas Column 3 Column 4 Column 4

1050 77.9 75.2 71.2 -2.7 -4.0 -6.7

1060 81.9 79.2 75.1 -2.7 -41 -6.8

1070 85.9 83.2 78.6 -2.7 -4.6 -7.3

1080 89.8 86.8 82.2 -3.0 -4.6 -7.6

1090 93.9 90.7 85.6 -3.2 -5.1 -8.3

1100 97.8 94.5 89.5 -3.3 -5.0 -8.3

1110 102.0 98.7 93.4 -3.3 -5.3 -8.6

1120 106.1 102.8 97.3 -3.3 -5.5 -8.8

1130 110.4 106.9 101.8 -3.5 -5.1 -8.6

1140 114.5 110.8 105.9 -3.7 -4.9 -8.6

1150 119.4 115.2 111.6 -4.2 -3.6 -7.8

1160 124.4 120.2 118.7 -4.2 -1.5 -5.7

1170 129.4 125.1 125.6 -4.3 +0.5 -3.8

1180 134.6 132.1 132.3 -2.5 +0.2 -2.3

1190 139.9 138.5 138.9 -1.4 +0.4 -1.0

1200 145.2 144.7 144.9 -0.5 +0.2 -0.3

1210 151.3 151.0 151.2 -0.3 +0.2 -0.1

1220 156.8 156.7 157.1 -0.1 +0.4 +0.3

1230 163.2 163.3 163.3 +0.1 0.0 +0.1

Totals 3,336.3 3,194.3 3,074.0 -142.0 -120.3 -262.3

65
Table 3-5

AREA OP LAKE HEAD AS A FONCTI(84 OF ELEVATION

XV BASINS

AS DETERHTINES FOLL(IX4INC TIlE 7963-1964 SUEVEY

December 6. 7966

Basins

Boulder

Basin

I-X

Boulder

Canyon

X+Y

Virgin

Basin

2-0

Temple Bar

Area

3A

Virgin

Canyon

3N

Gregg

Basin

4

Grand

Bay

5

Pierce Granite

Basin Gorge

6 7

Oserten

Arm

8

Elenatuana Acres Totals

739 37.72 37. 12

740 2,078.67 2,078. 67

750 4,127.7? 22.86 4,750. 63

760 5,001,86 220.91 5,222. 57

770 5,406.31 743.67 6.09 6,156. 07

780 5,786.46 78A.99 692,22 7,247. 67

790 6,127.15 809.38 1,750.99 8,681. 49

800 6,527,71 866.24 4,932.20 17,326. 23

810 6,924.03 920.05 6,646,60 .60 14,491. 28

820 7,320.77 949,32 7,874,02 7,88 16,151. 99

830 7,718,70 974,02 8,670,75 311.89 17,671. 36

840 8,127.46 1,006.46 9,531.26 916,03 19,581. 27

850 8,490.23 1,067.02 10,434.03 1,538.40 21,529. 68

860 9,039.40 1,135,52 11,160.88 1,072,11 77.00 23,284. 91

070 9,500.01 1,187.07 11,880.89 2,035.92 200.30 24,092. 2?

880 9,949.61 1,234.96 12,511.63 2,191.82 409.B5 4.03 .71 26,303. 21

890 iS,43A.62 7,283.92 13,149.30 2,394.64 444.15 116.40 46.05 27,873. 08

900 10,982.36 1,367.17 13,812.38 2,578.21 496.01 592,99 120.77 29,049. 89

910 11,528.43 1,570.78 14,821.65 2,743,46 538.98 1,283.83 159,29 32,308. 39

920 12,035,70 7,520.24 15,589.66 2,940.50 557.42 7,715.23 254.13 34,612. 88

930 12,599.58 1,617.77 16,580.86 3,123.21 579.17 2,030.59 379.06 36,910. 77

948 13,149.02 1,600.17 17,268.57 3,340.56 598.84 2,487.61 609.98 39,133. 95

950 13,757.50 1,771,26 18,000,17 3,888.15 641,50 2,914.15 894.59 41,567. 32

960 14,371,70 1,871.46 18,785.06 3,824,66 897.72 3,291 .73 1,333.77 44,168, 70

970 14,921,48 1,931,26 19,560.30 4,075.74 712.87 3,645.07 7,830.10 46,676. 10

980 15,496.54 2,004.09 20,334.04 4,271.49 740.79 4,004.09 2,268.25 49,119. 29

990 16,084.09 2,062,40 21,096.47 4,524.06 766.59 4,334.67 2,800.46 11,638. 70

1000 16,707.98 2,169.43 22,087.83 4,792,87 818.94 4,657.99 3,658.80 54,815. 54

1010 17,408.59 2,266.78 22,999.21 5,138.29 871.02 5,057.53 4,369.01 58,108. 43

6020 12.992,14 2,335.68 23,903.15 5,440.26 096.68 5,421.03 3.91 5,162.25 67,155. 50

1030 18,595.46 2,403.17 24,936.22 5,722.88 929,43 5,698.82 78.38 5,857.22 64,268. 58

1040 79,214.53 2,472.82 25,026.51 6,106.02 959.08 5,974.17 163.75 6,739,58 67,456. 46

1080 19,889.36 2,592.72 26,819.78 6,382.42 1,017,40 6,314.58 278.63 7,867.32 71,159. 61

1060 20,573.13 2,694.81 27,864.45 6,729.56 1,086,4? 6,638.92 375.66 9,166.67 75,129. 61

1070 21,210.00 2,735.52 28,670.8? 7,074.80 1,131.18 6,925.36 450.56 70,436.35 78,824. 64

1080 21,858,36 2,823.69 29,605.85 7,407.89 1,179.06 7,192.50 637.52 17,531.99 82,236. 66

1890 22,467.26 2,923.05 30,564.00 7,753.58 1,219.94 7,477.90 727.66 12,516.62 85,650. 01

3100 23,178,63 3,052.26 31,573.06 8,752.60 1,292.10 7,825.16 834.60 13,562.13 89,470. 62

1110 23,935.35 3,163.87 32,415.00 8,558.87 1,366.26 8,147.99 1,054.64 14,810.22 93,452, 20

1020 24,582.49 3,211.35 33,183.90 9,004,89 1,417.48 8,422.43 1,508.44 15,965.28 97,281. 26

1130 25,278.35 3,265,07 34,098.00 9,409.09 1,458.27 8,691.36 2,539.73 17,058.70 101,798. 57

9148 26,016,25 3,332.64 34,919,74 9,767.53 1,499,97 9,992.15 3,714.68 18,274.23 105,917. 19

1150 27,286,82 3,501.04 35,919,13 70,218,92 1,573.68 9,418,40 3,477.93 7.10 20,148,37 171,551. 37

7160 27,784.26 3,576,89 37,966,00 70,603.25 1,593.39 9,717.97 4,047.35 1,304.36 219.81 21,928.98 179,733. 26

1170 28,697 .87 3,663,81 39,005,23 0,939,39 1,657.41 9,955,37 4,323.45 2,962.00 853.41 23,633.14 725,644. 70

1180 29,465.42 3,746.99 40,542.99 71,292.25 '787.89 10,207.04 4,534.25 3,333.30 2,212.94 25,830.18 732,272. 43

1190 30,281.01 3,837.93 41,248.77 1,688.93 7,932,77 10,461,69 4,737,15 3,540.60 3,784.27 27,544.52 38,869. 98

1200 31,134,78 3,957,63 42,334.28 2,037.79 7,866.69 10,739.73 4,974.86 3,609.27 4,383.34 29,847.79 744,892. 53

5270 32,723.03 4,914.92 43,6u0,87 12,405.79 7,993.67 17,038.69 5,236.82 3,955,55 4,650.45 32,174.80 157,223. 83

7220 33,024.49 4,106.24 44,973.70 12,665.81 2,039.23 11,269.39 3,466,84 4,059.52 4,967.63 34,669.79 57,072. 59

7230 33,893.09 4,197.72 46,241.11 13,953,18 2,169.70 77,547.48 5,723,83 4,292,9? 5,075,87 37,743,10 763,320. 29

66
Table 3-6

LAKE lEAD CAPACITY IN ACRE-FEET - LISTED BY BASIN 196364 SERVES DATA

Elevations

(feet>

Boulder

Basin

I-B

Boulder

Canyon

RAY

Virgin

Basin

2-F

Temple Bar

Area

38

Virgin

Canvun

3,

Gregg

Basin

4

Grand

Bay

5

Pierce Granite

Basin Gorge

6 7

Overtos

Arm

8

Totals

730 IC 59

740 10599 10599

753 42.110 12 42.127

760 04,442 7,231 89,673

770 140697 6,720 3 746,820

780 196,515 13,785 3,498 273,868

790 256,007 21,772 14,687 292,466

900 319,236 30,138 47,836 397,210

810 386,501 39,083 106,539 4 532,124

820 457.726 40,444 129.524 47 685,741

030 532,921 58,061 262,402 1,403 854,787

840 612,170 67,951 353,371 7,413 1,040,905

850 695,202 78,306 453,256 19,800 1,246,564

B60 782,008 99,328 561,307 37,044 39 1,470,526

870 870,592 100,953 676,559 56,660 1,827 0,711,591

880 972,875 113,060 798,547 77,784 5,350 3 1 1,967,039

890 1,074,776 125,640 526,850 100,708 9,635 613 237 2,230,489

900 1,181,861 138,869 1,061,589 125,591 14,357 3,923 1,077 2,527,267

910 1,294,434 153,292 1,203,637 152,195 19,550 13,328 2,470 2,838,906

920 1,412,266 168,466 1,354,623 180,609 25,043 20,480 4,504 3,173,591

930 1,535,214 184,138 1,515,595 210,922 30,727 47,202 7,616 3,531,414

940 1,663,703 200,n30 1,684,954 243,716 36,604 69,751 12,499 3,911,377

950 1,798,250 217,873 1,861,261 277,855 42,794 96,794 19,939 4,314,766

960 1,938,921 236,100 2,044,173 314,920 49,410 127,857 30,955 4,743,416

978 2,085,405 255,126 2,236,907 354,442 56,459 162,553 46,817 5,197,709

980 7,237,495 274,807 2,436,387 396,180 63,727 200,810 67,298 5,676,704

990 2,395,218 295,129 2,643,483 440,129 71,251 242,518 92,475 6,180,208

1000 2,558,973 316,274 2,858,912 486,080 79,176 287,511 724,657 6,712,183

1010 2,729,599 338,474 3,083,951 536,328 87,641 336,130 164,780 7,276,881

1020 2,906,614 361,502 3,318,440 589,227 96,490 388,572 2 212,447 7,073,302

1030 3,089,539 385,199 3,562,653 645,282 105,622 444,211 402 207,509 8,900,417

1040 3,270,565 409,560 3,816,486 704,699 115,059 502,553 1,582 330,317 9,158,821

1050 3,474,060 436,073 4,079,656 767,128 124,927 963,980 3,784 403,183 9,851,601

1060 3,676,395 461,343 4,353,158 932,673 135,455 628,773 7,063 488,296 10,503,150

1070 3,885,273 408,503 4,635,982 901,703 146,553 696,620 11,161 586,398 11,352,093

lOBS 4,700,572 516,278 4,927,205 574.119 158,110 767.214 16,599 696,359 12,156,456

1090 4,322,179 544,997 5,228,026 1,049,900 170,096 840,535 23,462 916,626 12,995,921

1100 4,550,351 574,972 5,538,762 1,129,411 182,646 917,039 31,224 946,905 13,871,219

1110 4,785,957 605,989 5,850,804 1,212,949 195,948 996,935 40,531 1,088,736 14,785,849

1120 5,028,492 637,891 6,186,771 1,300,772 200,882 1,709,011 53,015 1,242,601 15,739,315

1130 5,277,679 670,264 6,523,163 1,392,800 224,262 1,165,372 73,210 1,407,778 16,734,610

1140 5,533,924 703,211 6,868,227 1,488,747 239,042 1,253,727 101,760 1,584,024 17,772,756

1110 5,800,743 737,377 7,221,912 1.508,670 254,421 1,345,787 134,729 4 1,776,008 18,859,451

1160 6,076,068 772,804 7,591,324 1.692,830 270,262 1,441,515 172,394 652 1,142 1,986,452 20,005,443

1170 6,358,122 009,006 7,976,556 1,000,559 286,507 1,539,870 214,399 21,984 6,038 2,214,160 21,227,202

1105 6,648,733 846,061 8,372,271 1,911,708 303,310 1,640,682 258,719 54,059 21,000 2,460,394 22,516,940

1190 6,947,455 883,961 8,779,233 2,026,467 320,922 1,744,018 305,066 81,520 51,151 2,726,148 23,972,936

1200 7,254,450 922,074 9,197,027 2,144,962 339,313 1,850,069 353,905 124,725 92,200 3,012,909 28,291,979

1210 7,570,724 962,306 4,627,099 2,267,231 358,621 1,950,928 404,667 162,642 137,429 3,322,914 26,772,567

1220 7,896,519 7,002,919 10,070,137 2,392,555 370,786 2,070,433 458,193 202,353 105,108 3,657,074 28,314,107

1230 8,231,094 1,044,441 10,529,028 2,521,078 399,759 2,184,395 514,126 244,070 234,828 4,010,152 29,915,772

67

Table 3-7

LAKE AD CAPACITIES IN ACRE-FEET - LISTED BY BASIN FOR 1935, 1948-49, 1963-64 SURVEYS

Kiev Loulder and Virgin Basins

Temple Bar area and

Virgin Canyon Cregg Basin Grand Ray J Pierce BaSin Lower Granite Gorge Overton Arm Totals

(it) 1935 1948 49 1963 64 1935 1948 49 1963 6 1935 1948 49 1963 64 1935 1948 49 196 64 1935 1948 49 1963 64 1935 1948 491963 64 1935 1948 49 1963 64 1935 1948 49 1963 6

650

660 1,000 1,000

670 7,000 7,000

680 21,000 21,000

690 43,000 43,000

700 73,000 73,000

710 111,000 111,000

720 156,000 156,000

730 207,000 19 207,000

740 265,000 10,599 265,000 10,5

750 336,000 15,000 42,127 336,000 15,000 42,U

760 422,000 69,000 89,673 1,000 423,000 69,000 89,6

770 518,000 124,000 146,820 3,000 521,000 134,000 146,8i

780 626,000 213,000 213,868 7,000 633,000 213,000 213,91

790 745,000 312,000 292,466 15,000 760,000 312,000 292,41

800 877,000 441,000 397,210 27,000 1,000 905,000 441,000 397,21

810 1,026,000 589,000 532,123 41,000 1 2,000 1,069,000 589,000 532,12

820 1,189,000 752,000 685,694 57,000 6,000 47 3,000 1,249,000 758,000 685,74

830 1,365,000 928,000 853,384 76,000 19,000 1,403 7,000 1,448,000 947,000 854,78

840 1,553,000 1,116,000 1,033,492 95,000 36,00C 7,413 15,000 1,663,000 1,152,000 1,040,90

850 1,755,000 1,318,000 1,226,764 116,000 57,000 19,800 28,000 1,899,000 1,375,000 1,246,56

860 1,970,000 1,533,000 1,433,443 139,000 80,000 37,083 46,000 1,000 1,000 2,156,000 1,614,000 1,470,52

870 2,197,000 1,760,000 1,653,104 164,000 105,000 58,487 68,000 5,000 2,000 2,431,000 1,870,000 1,711,59

880 2,437,000 2,000,000 1,884,500 191,000 132,000 83,135 92,000 15,000 3 5,000 1 2,725,000 2,147,000 1,967,63

890 2,690,000 2,253,000 2,127,276 220,000 161,000 110,363 120,000 31,000 613 9,000 237 3,039,000 2,445,000 2,238,48

900 2,955,000 2,518,000 2,382,319 251,000 192,000 139,948 150,000 53,000 3,923 15,000 1,000 1,000 1,000 1,077 3,373,000 2,764,000 2,527,26

910 3,234,000 2,797,000 2,651,363 285,000 226,000 171,745 182,000 79,000 13,328 21,000 3,000 1,000 3,000 3,000 2,470 3,729,000 3,105,000 2,838,90

920 3,529,000 3,092,000 2,935,355 321,000 262,000 205,652 215,000 108,000 28,480 29,000 6,000 4,000 6,000 6,000 4,504 4,110,000 3,468,000 3,173,99

930 3,837,000 3,400,000 3,234,947 360,000 301,000 241,649 251,000 141,000 47,202 38,000 11,000 7,000 11,000 11,000 7,616 4,515,000 3,853,000 3,531,41

940 4,161,000 3,724,000 3,549,307 401,000 342,000 279,820 291,000 178,000 69,751 47,000 16,000 11,000 16,000 16,000 12,499 4,943,000 4,260,000 3,911,31

950 4,498,000 4,061,000 3,877,384 445,000 386,000 320,649 332,000 218,000 96,794 57,000 22,000 16,000 25,000 25,000 19,939 5,395,000 4,690,000 4,314,761

960 4,851,000 4,414,000 4,220,194 491,000 432,000 364,370 375,000 261,000 127,857 67,000 1,000 29,000 22,000 38,000 38,000 30,995 5,873,000 5,146,000 4,743,411

970 5,218,000 4,781,000 4,577,438 540,000 481,000 410,901 419,000 305,000 162,553 79,000 3,000 36,000 29,000 55,000 55,000 46,817 6,376,000 5,625,000 5,197,701

980 5,598,000 5,161,000 4,948,689 591,000 532,000 459,907 467,000 353,000 200,810 91,000 7,000 44,000 37,000 76,000 76,000 67,298 6,904,000 6,130,000 5,676,70i

990 5,994,000 5,557,000 5,333,829 647,000 588,000 511,384 516,000 402,000 242,518 104,000 14,000 52,000 48,000 104,000 104,000 92,475 7,465,000 6,665,000 6,180,201

1000 6,405,000 5,968,000 5,734,159 705,000 646,000 565,856 567,000 453,000 287,511 118,000 24,000 61,000 59,000 139,000 139,000 124,657 8,054,000 7,230,000 6,712,181

1010 6,832,000 6,395,000 6,152,002 766,000 707,000 623,969 621,000 507,000 336,130 132,000 36,000 71,000 73,000 182,000 182,000 164,780 8,677,000 7,828,000 7,276,881

1020 7,275,000 6,838,000 6,586,564 830,000 771,000 685,717 678,000 564,000 388,572 148,000 51,000 2 81,000 87,000 233,000 233,000 212,447 9,332,000 8,458,000 7,873,302

1030 7,735,000 7,298,000 7,037,341 899,000 840,000 750,904 736,000 622,000 444,211 166,000 69,000 402 91,000 103,000 292,000 292,000 267,509 10,022,000 9,121,000 8,500,417

1040 8,212,000 7,775,000 7,504,611 969,000 910,000 819,758 797,000 683,000 502,553 184,000 87,000 1,582 103,000 3,000 120,000 361,000 361,000 330,317 10,746,000 9,819,000 9,158,821

1050 8,704,000 8,267,000 7,988,589 1,043,000 984,000 892,065 861,000 747,000 563,980 204,000 107,000 3,784 117,000 9,000 138,000 439,000 439,000 403,183 11,506,000 10,553,000 9,851,601

1060 9,214,000 8,777,000 8,490,896 1,121,000 1,062,000 968,128 928,000 814,000 628,773 224,000 127,000 7,063 131,000 16,000 159,000 528,000 528,000 488,296 12,305,000 11,324,000 10,583,156

1070 9,739,000 9,302,000 9,009,658 1,202,000 1,143,400 1,048,256 998,000 884,000 296,620 247,000 150,000 11,161 146,000 27,000 181,000 631,000 630,000 586,398 13,144,000 12,136,000 11,352,093

1080 10,281,000 9,844,000 9,544,055 1,288,000 1,229,000 1,132,229 1,069,000 955,000 767,214 271,000 174,000 16,599 163,000 40,000 204,000 746,000 744,000 696,359 14,022,000 12,936,000 12,156,456

1090 10,841,000 10,404,000 10,095,202 1,377,000 1,318,000 1,219,996 1,144,000 1,030,000 840,535 296,000 199,000 23,462 181,000 54,000 228,000 874,000 869,000 816,626 14,941,000 13,874,000 12,995,821

1100 11,418.000 10,981,000 10,663,985 1,470,000 1,411,000 1,312,057 1,222,000 1,108,000 917,038 323,000 226,000 31,224 200,000 70,000 255,000 1,012,000 1,004,000 946,915 15,900,000 14,800,000 13,871,219

1110 12,013,000 11,576,000 11,250,750 1,567,000 1,508,000 1,408,897 1,303,000 1,189,000 996,935 352,000 255,000 40,531 222,000 88,000 282,000 1,160,000 1,150,000 1,088,736 16,899,000 15,766,000 14,785,849

1120 12,625,000 12,188,000 11,853,154 1,669,000 1,610,000 1,510,654 1,387,000 1,273,000 1,079,811 383,000 286,000 53,015 244,000 107,000 311,000 1,320,000 1,309,000 1,242,681 17,939,000 16,773,000 15,739,315

1130 13,256,000 12,819,000 12,471,108 1,775,000 1,716,000 1,617,142 1,474,000 1,360,000 1,165,372 415,000 318,000 73,210 268,000 129,000 342,000 1,492,000 1,480,000 1,407,778 19,022,000 17,822,000 16,734,610

1140 13,904,000 13,467,000 13,105,356 1,885,000 1,826,000 1,727,789 1,564,000 1,450,000 1,253,727 450,000 353,000 101,760 293,000 152,000 375,000 1,675,000 1,662,000 1,584,124 20,146,000 18,910,000 17,772,756

1150 14,569,000 14,132,000 13,759,832 1,999,000 1,940,000 1,843,091 1,656,000 1,542,000 1,345,787 488,000 391,000 134,729 319,000 177,000 410,000 4 1,874,000 1,857,000 1,776,008 21,315,000 20,039,000 18,859,451

1160 15,254,000 14,872,000 14,440,196 2,116,000 2,057,000 1,963,092 1,752,000 1,638,000 1,441,515 527,000 430,000 172,394 349,000 205,000 652 447,000 1,142 2,089,000 2,069,000 1,986,452 22,534,000 21,216,000 20,005,443

1170 15,959,000 15,522,000 15,143,684 2,239,000 2,180,000 2,087,066 1,851,000 1,737,000 1,539,871 570,000 473,000 214,399 378,000 234,000 21,984 486,000 6,038 2,320,000 2,297,000 2,214,160 23,803,000 22,443,000 21,227,202

1180 16,685,000 16,248,000 15,867,065 2,365,000 2,306,000 2,215,026 1,951,000 1,837,000 1,640,682 613,000 516,000 258,719 411,000 267,000 54,059 526,000 14,000 21,000 2,570,000 2,544,000 2,460,394 25,121,000 23,733,000 22,516,945

1190 17,432,000 16,995,000 16,610,644 2,495,000 2,436,000 2,367,389 2,055,000 1,941,000 1,744,018 660,000 563,000 305,066 445,000 301,000 88,520 569,000 40,000 51,151 2,840,000 2,812,000 2,726,148 26,496,000 25,087,000 23,872,936

1200 18,197,000 17,760,000 17,374,156 2,630,000 2,571,000 2,494,279 2,161,000 2,047,000 1,850,009 709,000 611,000 353,605 481,000 337,000 124,725 614,000 77,000 92,200 3,129,000 3,099,000 3,012,909 27,920,000 26,502,000 25,291,879

1210 18,984,000 18,547,000 18,160,129 2,769,000 2,710,000 2,625,852 2,270,000 2,156,000 1,58,928 758,000 661,000 404,667 519,000 375,000 162,642 661,000 122,000 137,429 3,442,000 3,410,000 3,322,914 29,403,000 27,982,000 26,772,561

1220 19,797,000 19,360,000 18,969,575 2,912,000 2,853,000 2,771,371 2,381,000 2,267,000 2,070,433 812,000 715,000 458,193 558,000 414,000 202,353 710,000 169,000 185,108 3,775,000 3,742,000 3,657,074 30,945,000 29,520,000 28,314,107

1230 20,632,000 20,195,000 19,801,363 3,059,000 3,000,000 2,920,837 2,495,000 2,381,000 2.184,395 867,000 770,000 514,126 600,000 456,000 244,070 760,000 219,000 234,829 4,134,000 4,100,000 4,016,152 32,547,000 31,121,000 29,915,772

69
) ACRES

7 6 5 4 3 2 I 0

' H

I

N

e\

Area

) (acres)

_ _

-i

20 162,000

70 /57,900

_____ _____

\

_____ _____ _____ -

____ i

,

________

lB 20 22 24 26

LIONS OF ACRE-FEET

t.

28 30 32

LAKE MEAD

AREA AND CAPACITY CURVES

(BASED ON /963-64 SURVEY)

I


---------

-n

C)

C

m

3€

4

34

2 z

232

-I1

-. *30

z

•1229-(,,28

I- 5 z

220-Wi- 26

.t2I0- 0-

l.

W1200- lu -

Id -

IA.

1190-422 z

iieo- <-

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III 0- -

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1090_z -

toe o

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1010- A

1080- -

1080- 8

I040-

-t030- -

1020-

1010- -

1000-

-980- Id -

940

920

895- C

1961

I contents in Lake

of month Quont tisi

09S

NOTE

Data shown hereon were obtained from water supply papers published by the

Geological Survey for the period prior to October, 1966.

05(1(0 STATES

DC P05151*? 01 1*1 51(5(0*

5051*0 01 5ECLA*A1O5

REGION 3

RIVER OPERATION DATA

HYDROGRAPHS

HOOVER DAM AND LAKE MEAD

COLORADO RIVER

- -

bALDER CITY, 5(0 10- Il-ST

tHEFT S Of S 45-300-90

I

PART 4-INVESTIGATIONS

OF SEDIMENT PROPERTIES

Methods of Field Investigation

Field investigations during the 1963-64 survey of Lake

Mead included the collection of sediment samples at

the 17 reservoir locations shown in Figure 4-1. These

sampling sites were chosen because they were near

those of the 1948-49 survey. The sampling was done in

two separate phases of collecting samples to determine

certain physical and chemical characteristics of the

accumulated sediments. Modern instrumentation, field

sampling techniques, and laboratory analysis

procedures are described. An interpretation of the

sediment properties is made.

The first sampling phase was made in the fall of 1963.

The objective was to use standard drilling equipment to

obtain undisturbed drive samples of the delta

formation. A dry delta area in Pierce Basin near River

Mile 278 was selected as the test site designated Drill

Hole DH-1 (Figure 4-1). The site was located over an

old channel just downstream from the mouth of Lower

Granite Gorge (Figure 4-2) on a silty sand deposit

about 80 feet north of the present channel right bank.

A heavy stand of salt cedars averaging about 5 feet high

completely covered this delta and had to be cleared

before the drilling camp could be established (Figure

4.3)

The sampling operation was rather unique because a

helicopter was needed to transport personnel and

drilling equipment to the site (Figure 44). The

equipment was moved to Pierce Ferry by truck and

then airlifted about 2 miles to the delta area. It took

the helicopter 42 flights and nearly 8 hours to

transport personnel and equipment cumulatively

weighing about 18,000 pounds. The helicopter was also

needed to remove the equipment after the operation.

The ground elevation at the drill hole was 1161 feet or

about 12 feet above the river stage. The drill rig setup

allowed control of the sampling to a 207-foot depth in

the delta formation.

The second sampling phase was carried out a year later

in the fall of 1964. The objective was to collect

piston-core samples of the inundated reservoir

sediment deposits and to use a nuclear gamma probe to

get a reading of the density and consolidation effects

of the deposits at 16 selected investigation sites (Figure

4-1).

Floating equipment was used to obtain sampling data

by both the piston-core and gamma probe. The

equipment consisted of a 45-foot working barge, a

105-foot barge used to house personnel and as a base

of operations, and a 35-foot cruiser to transport

supplies and personnel (Figure 4-5). The barges were

self-propelled by on-board gasoline and diesel engines

giving the mobility needed to proceed to any desired

location (Figure 4-6). Measuring 21 feet by 45 feet, the

working barge platform furnished ample space for both

personnel and for the derrick, sampler hoist, anchor

hoist, and other miscellaneous equipment. A schematic

deck layout view in Figure 4-7 shows the relative

positions of some equipment.

Samples totaling 215 were collected from the 17

locations in Lake Mead during 1963 and 1964. The

samples were analyzed in the laboratories of the

Division of Research, Office of Chief Engineer, Denver,

Colorado.

Drive Sampling

The drill rig used at Site DH-1 (Figure 4-1) was a

skid-mounted unit-hydraulically fed, chain-belt

driven, and powered with a four-cylinder gasoline

engine (Figure 4-8). A mud pump powered by a

four-cylinder air-cooled gasoline engine, trailer

mounted, was also used. Undisturbed samples were

obtained at 5-foot intervals with a modified thin-wall

open-drive sampler (Figure 4-9). The 36-inch-long

sampling tube had a 3-inch outside diameter and a No.

14-gage wall thickness and was made of cold-drawn

steel tubing. Its cutting edge was sharpened with the

bevel on the outside. The inside diameter equal to or

slightly less than that of the tube gave internal

clearance to allow the sample to enter the tube easier

and to assist retaining the sample. The sampling tube

fits a modified sampler head having vents for the

drilling mud to escape. The modified sampler head was

equipped with an "0" ring seal and a rubber-seated ball

check valve to prevent the drilling mud from entering

during the withdrawal operations and to assist in

creating a partial vacuum above the sample needed to

retain the sediment core. Attached to a string of "N"

drill rods (2-inch inside diameter, 2-3/8-inch outside

diameter) the thin-wall sampler was hydraulically

forced without rotation into the sediment in one

continuous stroke. After penetration, the sampler was

rotated to break off the sediment at the bottom and

then the drill rod with the sediment bearing sampler

was carefully removed from the hole.

The drilling between undisturbed sampling elevations

was advanced with a double-tube sampler (Figure

4-10). Principal components of this sampler consisted

of a rotating outer barrel with cutting teeth on the

bottom, a nonrotating inner barrel with a smooth

75

14°45 114°30 '4I5'

\--

5EP1Pi1T/ON

C4NYON

NEISS -

NYON --

RR/flF N_

FIGU

77

3545 I445 JI43O H45 H4OO 45 CNYON I33Q
-. --

-

-

E .itIrui

_____

- -.- -.--

..-..

• ' -

'- - . .

View of Pierce Basin looking northeasterly from a high ridge just north of Pierce Ferry.

Photo P45D-4O589 NA

p

-

View looking west across Pierce Basin from the mouth of lower Granite Gorge. The

drilling site was located approximately 80 feet north from the right bank of the present

Colorado River channel at the point where the channel narrows near the center of the

photo. Photo P45-D-40600 NA

FIGURE 4-2

79
E

.

+-

4

/

i44

T; -

,- ; •- J•__ - .. f I ..r

:

I2c;;r

,

Surface cracks on dry area of Lake Mead delta topset beds. Picture was taken

approximately in the center of Pierce Basin. Salt cedar can be seen growing in the

background. Photo P451140597 NA

,

1 - J -

Establishing drilling site on Lake Mead delta. Salt cedars averaging about 5

feet high had to be cut down before equipment could be flown in. Photo

P45-D-41 749NA

FIGURE 4-3

80

- -,. - -,- .-_-_ . -

r- -
I

- - -

- •4* -

iT __

k

I

Helicopter picking up equipment at Pierce Ferry. Heavy equipment had to

be dismantled in order to make up loads that the helicopter could handle.

Bundles of casing and drill rod shown in foreground. Photo P45-D-41750

NA

• '.-

.

Helicopter carrying equipment with a cargo net. All drilling and camping

equipment needed in the delta investigation had to be flown in and out by

helicopter. Photo P45-D-41 751 NA

FIGURE 4-4

81
-._

- -. -

-4__ -.

- -

Port and stern view of the barges used in sedimentation investigation.

Photo P45-D-46832 A

h'

-

4I

•

_.

.. -

-I.

- - _.--- -- -- • •-

_

- ----

:--- ••-

-----

---- - -

- - • .

- .- - -- -

-

- - -

-

- -

_-,_r- - -

--

- L - -

-

.

- •- _ -' - .-'

Starboard and stern view of the barges used in sedimentation investigation

Photo P45-D-46833 A

FIGURE 4-5

82
Stern view of barges used in sedimentation investigation. Photo

P45-D-46834 A

T'4' :" Tf$:

I

I

Sea mules used as propulsion units for barges. Photo P45.D-46835 A

FIGURE 4-6

83

fram

Use I "pipe far spacer

between sheaves

SEDIMENTATION INVESTIGATION BARGE

DECK LAYOUT

FIGUR

85
354 350 14E 142 330 334 SOD SOS SO'.

------ -------------------

-

,,,,,,,,,,,,,,,,,,,

_______________________________________ I I_________________

-

I I I I I I I

PROFILE WITH NO VERTICAL EXAGGERATION-_S

'. 5(L) ZOO tO? ?Oti to'. tON 205 24? 258 234

_____________________________________________________________________________________/2//632

FT

250

250

MAX. RECORDED WATER SURFACE ELEVATION (JULY. I94I)-I22O45,, /

-- HOOVER DAM

/

120 - NOTE; WIDTH NOT TO SCALE

1200

&/3',S't'' -

1150

fl A T

-

-

JtrJ

150

1100 -

/

- 1100

,--I963-64 / -I948-49

/ / 050 -

/ / - 1050

/

/

<--DRILL HOLE No /

U

- /

207 FEET

000 / /

/ - 1000

'C

Z /

'

950 -

/ /

- 950

'C 35 FEET-' "C

900 <

OUTLET GATE SILLS EL. 595 0 / 7 ORIGIN4L COLORADO RIVER PROFILE (1935)

_____________________________________________ 7' - 900

I- -

-CU -

- -CU

-

-

.

-C-

- - - -

- -' - -

850 - ,,,-- ,_-

- - 850

- -

- -

800 -

--GREGG BASlN-- ---GRAND BAY-- LOWER GRANITE GORGE - 800

U

ICEBERG

rffO

750 -

- 750

---TEMPLE BAR AREA------ 700 -

- 700

650

- - - - BOULDER BASIN

- - .-

0 ER

CANO}4 - VIRGIN BASIN - - -.

- 650

'-BLACK CANYON

I I I I I 354 350

t 346 342 338 334 330 326 322 318 314 3(0 306 302 298 294 290 286 282 278 274 270.,,,_._. __.... ._._.._ ---

266 262 258 254 250 246 242 238 234

500

DISTANCE ALONG COLORADO RIV ER CHANNEL MEASURED IN MILES FROM U.S.G.S. CONCRETE GAGE WELL OPPOSITE MOUTH OF PARIA RIVER, ARIZONA

UN/TED STATES

DEPARTMENT OF THE INTER/DO

05/REAL) C/F $ECLAMAT,ON

LAKE MEAD

LONGITUDINAL PROFILES

COLORADO RIVER

-

rRAc,o_q/75 RECOMMENOEO,

CHECKED 2' -. APPROVED

SO/fl. DER C/K)', REV OCT /8, /960

7-Zflfl

- FIGURI
hole was about 35 feet short of reaching the 1935 river

bottom. The present foreset beds are seen to extend

from River Mile 282 to about River Mile 304 in Virgin

Canyon with the bottomset beds running from here on

down to the dam.

The longitudinal profiles of the Virgin River are

plotted in Figure 5-4. The pattern of sediment

deposition is similar to that of the Colorado River

except on a smaller scale. Records were not available to

trace the 1948-49 profile throughout the reach. The

1963-64 profile is already exhibiting a delta buildup

between River Miles 25 and 36. Below this point the

inflowing sediments deposit in a sporadic pattern along

the reach. The profiles were plotted along the original

(1935) thalweg course. Several depressions and saddles

were noted in the topography used to plot the 1963-64

profile. These resulted in the peaks or depressions

shown on this profile. These variations in the profile of

the wide sections of the northern part of Overton Arm

may have been caused by flood inflow from the Virgin

River and side washes during periods of low Lake Mead

water-surface elevations which resulted in formation of

braided stream topography. In the narrow canyon

sections of the southern portion of Overton Arm, slides

from the canyon walls caused by dissolving of soluble

materials from the Muddy Creek formation probably

formed mounds in the profile.

In the upper region of the reservoir on the Colorado

River consisting of the Grand Bay, Pierce, and Lower

Granite Gorge Basins is where about 47 percent or 1.24

million acre-feet of the total sediment deposited since

1935. The Overton Arm (Virgin River) showed about 4

percent or 120,000 acre-feet of the total sediment

accumulation for the same period.

Measured Reservoir

Sediment Volumes

The sediment volumes in Lake Mead by basins were

computed for two periods by subtracting the

differences in computed capacities. Listed in Table 5-1

are the sediment volumes by basins accumulated

between 1948-49 and 1963-64. The sediment volumes

listed in parentheses in this table for Boulder Basin to

elevation 830 feet, all of Lower Granite Gorge, and

from elevation 880 to 900 feet for Overton Arm,

indicate a gain in capacity in these areas between the

1948-49 and 1963-64 surveys. The total sediment

volumes that have accumulated within each basin of

Lake Mead since 1935 are listed in Table 5-2.

Measured and Estimated

Sediment Inflow

The gaging station and suspended sampling station of

the Colorado River at Grand Canyon, Arizona, about

270 miles upstream from Hoover Dam, provided the

data for determining part of the sediment inflow to

Lake Mead. The graph in Figure 5-5 gives an idea of the

enormous quantities of sediment carried by the

Colorado River. Plotted in this graph are the monthly

suspended sediment loads in thousands of tons

measured in the Colorado River near Grand Canyon,

Arizona, from 1935 to 1964. To supplement the

sediment picture, the average monthly waterflows

measured at the same station are plotted in Figure 5-6

for 1923 to 1964. The measured quantity of suspended

sediment passing Grand Canyon was 3,025 million tons

from 1935 to 1963 excluding November 1942 through

September 1943 when the sLispended sediment was not

measured. This gives an average of 108 million tons per

year. The quantity passing this station was 1,012

million tons from 1949 to 1963.

Additional sediments flowing into Lake Mead are

contributed from the numerous Colorado River

tributaries below the Grand Canyon station and from

the Virgin River system. The frequency and magnitude

of runoff from these sediment-producing areas vary

extremely. Large quantities of sediments may be

moved in the tributaries during any of the isolated

torrential downpours characteristic of the arid climate

in the Southwestern United States.

Based upon the sediment records available, an estimate

of the sediment yield rate for Lake Mead from both

the Colorado and Virgin Rivers cannot be made with

any significant degree of practical accuracy. A variety

of factors also influence this estimate. Taking for

example only the records of the Colorado River station

near Grand Canyon, an annual total sediment load of

118.8 million tons was estimated assuming 10 percent

for the unmeasured load. Applying a unit weight of 60

pounds per cubic foot, this load converts to 90,900

acre-feet per year. This compares to the sediment rate

of 91,450 acre-feet per year determined from the

1963-64 survey showing a difference of 550 acre-feet.

The difference, however, is not judged to be

representative of the annual sediment yield rate for the

additional sediment that would be contributed to Lake

Mead from both the Colorado River drainage area

below the Grand Canyon station and the drainage area

of the Virgin River. Regarding the analysis of the

157
I 2 so.1

_

I200

ISO

I00

-J

(I)

050

w

>

0

4

uJ

000

z

0

4

950

uJ

900

850

800

750

36

J=

----1230

=L=±=I= =4=- =- -4--4-=#--+-H--

'Hydraulic gradient of Virgin R,yr

-4-

-

-I948 -i949 Profile

No±e Profile stohoning is

along original thalweg

- 1935 Profile \

,4963-1964 Profile

BOULDER CANYON PROJECT...,.

/963-64 LAKE MEAO SURVEY

VIRGIN RIVER

LONGITUDINAL PROFILES

R.C.0 2-i8--69

______ I I I I I I - I 1 ______

32 28 24 20 6 2 8 4 0

Figure 5-4. River miles above confluence of Virgin and Colorado Rivers.

1 58
Teble 5-1

SEDIBEST VOLUMES IN LAKE SEAS 85' BASINS 1948-49 to 1963-64

Sedloect Volu,,ee In 1000 .Bcre- feet

EIBnen1nn Boulder Boulder Virgin TernIe Ber Virgin Gregg Grand Piecer Granirn Overton

(feet) BoIu Cenyoe Boom area Conyon Basin Boy Basin Gorge Aru OetoIe

V-S X*Y 2-0 3A 38 4 5 6 7 8

740 (10.6) (18.6)

750 (27.1) (27.1)

760 (22.4) 1.0 (20.6)

770 (17.7) 3,9 .0 (129)

790 (14.6) 6.2 7.5 (0.9)

790 (13.0) 7.2 25.3 59,5

800 (9.2) 0.9 44.2 43.9

(10 (6.5) 10.9 52.5 56.9

(20 (3.7) 12.6 57.5 6.0 72.4

830 (0.9) 13.9 61.6 17.6 92.2

840 1.8 15.0 65.6 27.6 1.0 111.0

850 4.8 17.7 69.7 33.2 4.0 128.4

(60 9.2 19.7 71.7 35.0 9,0 1.0 143.6

870 10.4 21.0 73.4 36.3 10.2 5.0 158.3

880 13.1 22.9 79.4 37,2 11.4 15.0 179.0

890 16.2 25.4 84.1 38.3 11.5 30.4 206.6

900 19.1 27.1 89.4 40.4 11.6 49.1 (0.2) 236.5

910 22.6 28.7 94.4 41.8 11.9 65.7 0.5 269.6

920 26.7 30.5 99.4 44.4 12.0 79.5 1.5 294,0

930 29.8 30.9 104.4 47.1 12.3 93.8 3.4 321.7

940 33.3 33,4 108.0 49.8 12.4 108.2 3.5 348.6

950 36,8 34.1 112.1 52,1 13.2 521.2 5,1 375,2

960 40.1 35.9 117.8 54.1 13,5 133.1 1,0 7.0 402.5

970 43,6 36.9 123.1 56.6 13.6 142.4 3.0 8.2 427.4

988 46.5 37.2 128.6 58.8 13.7 152.2 7.0 8.7 452.7

990 49.8 38.9 134.5 62.9 13.6 159.5 14.0 11.5 484.9

1000 53.0 39.7 141.1 63.9 14.3 165.5 24.0 14,3 515.8

1010 55.4 40.5 147.0 68.7 14.4 170.9 36.0 17.2 550.1

1020 57.4 41.5 152.6 70.8 14.5 175.4 51.0 20.6 583.8

1030 55.5 42.8 158.3 13,1 15.2 177.8 68.6 24.5 620.4

1040 61.4 43.4 165.5 74.3 15,9 180.4 85.6 3.8 30.' 660.0

1050 62.9 44.1 171,3 75,9 16.1 183.0 103.2 9.0 35.8 701.3

1060 64.6 44.7 176.8 77.3 16.5 185.2 119.9 16,0 39.7 720.7

1070 64.7 45.5 182.1 78.3 16.7 187.4 138.8 27.0 43.6 783.1

1090 65.4 45.7 188.8 79.9 16.8 187.0 157.4 40.0 47.6 829.4

1090 65.8 47.0 196.0 81.1 16.9 189.5 175.5 54,0 52.4 878.2

1100 67.6 47.0 202.2 82.6 17.2 191.0 194.8 70.0 57.1 929.5

1110 69.0 47,1 209.2 93.1 17,7 192,1 214.5 88.0 61,3 982.0

1120 70.5 48,5 216.2 83.2 193.2 233.0 107.0 66,3 1,535.2

1130 14.3 48.7 224.8 83,3 194,6 244.8 129.0 72.2 1,009.4

1140 76.9 48,8 234.8 84.2 196.3 251.2 152.0 77.9 1,139,8

1150 78.9 49.6 245.1 85,1 196,6 255.9 177.0 81.0 1,186.9

1160 81,7 50.2 250,7 87,0 197.5 257.6 704.3 (1.1) 82,5 1,227.7

1170 51,6 252,4 199.2 258.8 211.9 (6.0) 82.8 1,236.9

1180 54.0 254.7 203.5 260.1 213.1 (7.0) 83.6 1,248.4

1190 256.8 205.4 263.7 215,7 (11.2) 83.8 1,254.6

1200 259.0 206.1 267.1 211,9 (15.2) 86.1 1,261.4

1210 259,9 269.8 220.1 (15.4) 88.2 1,269.1

1220 262.9 222.7 (15.8) 91,9 1,278,0

1230 278.0 (15.8) ),293.5

159
Table 5-2

SEDIMENT VOLUMES IN LAKE MEAD BY BASINS 1935 to 1963-64

Sediment Volumes in 1,000 Acre-feet

Temple

Elevations Boulder Bar area Gregg Grand Pierce Lower Overton

(feet) and Virgin and Virgin Basin Bay Basin Granite Arm Totals

Basins Canyon Gorge

650 0 0

660 1 1

670 7 7

680 21 21

690 43 43

700 73 73

710 111 111

720 156 156

730 207 207

740 254 254

750 294 0 294

760 332 1 333

770 371 3 374

780 412 7 419

790 453 15 0 468

800 480 27 1 508

810 494 41 2 537

820 503 57 3 563

830 512 75 7 594

840 520 88 15 623

850 528 96 28 0 652

860 537 102 46 1 686

870 544 106 68 2 720

880 553 108 92 5 758

890 563 110 119 9 0 801

900 573 111 146 15 1 0 846

910 583 113 169 21 3 1 0 890

920 594 115 187 29 6 4 1 936

930 602 118 204 38 11 7 3 983

940 612 121 221 47 16 11 4 1,032

950 620 124 235 57 22 16 5 1,079

960 631 127 247 67 29 22 7 1,130

970 641 129 256 79 36 29 8 1,178

980 649 131 266 91 44 37 9 1,227

990 660 136 273 104 52 48 12 1,285

1000 671 139 279 118 61 59 14 1,341

1010 680 142 284 132 71 73 17 1,399

1020 688 144 289 148 81 87 21 1,458

1030 698 148 292 166 91 103 24 1,522

1040 707 149 294 182 103 120 31 1,586

1050 715 151 297 200 117 138 36 1,654

1060 723 153 299 217 131 159 40 1,722

1070 729 154 301 236 146 181 45 1,792

1080 737 156 302 254 163 204 50 1,866

1090 746 157 303 273 181 228 57 1,945

1100 754 158 305 291 200 255 65 2,028

1110 762 306 311 222 282 71 2,112

1120 772 307 330 244 311 77 2,199

1130 785 309 341 268 342 84 2,287

1140 799 310 348 293 375 91 2,374

1150 809 310 353 319 410 98 2,457

1160 814 310 355 348 446 103 2,534

1170 815 311 356 479 106 2,580

1180 818 505 110 2,613

1190 821 518 114 2,633

1200 823 522 116 2,641

1210 824 523 119 2,646

1220 827 524 2,650

1230 831 525 2,655

60
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CD

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CD

CD

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SUSPENDED SEDIMENT LOAD - THOUSANDS OF TONS PER MONTH NEAR GRAND CANYON, ARIZO

e 0

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_

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0

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9p 9p4 I 19Z4 957 <,i9 930 9 I .9• ---- 934 955 936 93 ] 938 1939 J45 94

F C[J CJCQjI JAS1I U4C0C[0 F J8 051 MJs

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I I =

942 94 5 9 '5 946 9 47 946 14 9 55C 4 9 9 53 94 '9s 556 C' 958 9 59 960

JA r

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L t II

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NOTE

For conven ence, the maximum and minimum mean doily

discharge for each month were plotted at the middle of

the month, rather than on the day when the discharge occurred.

SYMBOLS

-flj - imsieraqe monthly discharge.

- Maximum mean doily discharge for mOnth.

Minimum mean daily discharge for month.

30

20

0

19

0

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This drawing supersedes drawing No X-306-i I

591150 594155

OEPAOTMENT OF 185 iNFERIOR

8UREAU OF RECLAMA1ION

LOWER COLORODO RIVFR BASIN

RIVER OPERATION DATA

AVERAGE MONTHLY DISCHARGE OF T

COLORADO RIVER NEAR GRAND CANYON, ARI

DRAWN EQ SUBMi5T50

TRACOD wa REcOMMSNDSD 2

-300-87

Sheet 1 o

163
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------ ------------- -----------

------

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a

100

90

80

70

60

50

40

30

20

IC

C

SYMBOLS

- 8oeroqe roontflly dischorge

- Moxorum rnxon doly dschorge for month

x - Mnimurn mean daily dIscharge for ronfh

NOTES

DATA SHOWN FIEREON WERE ONTAINED FROM WATER SUPPLY PAPERS PUBLISHED

BY THE GEOLOGICAL SURVEY FOR THE PERIODS PRIOR TO OCTOBER 1965.

FOR CONVENIENCE, THE MAXIMUM AND MINIMUM MEAN DAILY DISCHARGE FOR

EACH MONTH WERE PLOTTED AT THE MIDDLE OF TIlE MONTH, RATHER THAN ON

THE DAY WHEN THE DISCHARGE OCCURRED.

165

OArED STArES

OEFAR TMENT OF THE iNTERIOR

BUREAU OF RECLAMATION

LOWER COLORADO RIVER BASIN

RIVER OPERATION DATA

AVERAGE MONTHLY DISCHARGE OF THE

COLORADO RIVER NEAR GRAND CANYON,ARIZONA

DRAM N EU NORM

TRACED JB NEUOMMEHDEO/)

CHECKED

IDULOEB CAT, REHASH I 423-300-87

FIGURE 5-6
Colorado River records of the Grand Canyon station,

two of the more significant factors influencing the

estimated sediment yield rate are:

a. The percentage estimated for the unmeasured

load is assumed by judgment and a study of the

fluvial conditions therefore is subject to question.

b. The unit weight applied to convert the sediment

load to a volume is determined by a weighting

analysis (see description in right column) which is

subject to an individual interpretation of the

collected field sample data.

The sediment yield rate differences would be

further affected by the sediment depositional

pattern of the Virgin River before it enters the

reservoir proper. Some of the sediments transported

by this river deposit in the region above the

reservoir thus would not be accounted for in the

sediment accumulation rate determined by the

survey. Other factors affecting the yield rates

viewed from opposite ends would be the accuracy

to which both the measurements are made of the

suspended sediment loads of the Colorado River

near Grand Canyon and the actual field

measurements made during the 1963-64 survey

which serves as the reference base for comparison.

Trap Efficiency

Brune5' in a study related the trap efficiency to the

capacity-inflow ratio of several reservoirs and found a

reservoir trap efficiency of 99.4 percent for Lake

Mead. Based upon the current capacity-inflow ratio of

2.56 (see Item 33, Table 5-3), the trap efficiency for

Lake Mead would be 98 percent from the medium

curve of Brune's study cited previously. Direct

measurements of the sediment outflow have not been

made which precludes estimating the trap efficiency. It

is judged, however, that the trap efficiency for Lake

Mead can be considered equal to 100 percent for all

practical purposes.

Representative Particle

Gradation

Size analysis data of the collected sediment samples

were used to determine the mean particle size

gradation representative of the total sediment

accumulation. This was done by computing the mean

particle size gradations in percentages of clay, silt, and

sand for each lake basin. The representative particle

size gradation of the total sediments accumulated was

computed by weighting the clay, silt, and sand

percentages by the ratio of volume of sediment

accumulated in a given basin to the total sediment

accumulation in all basins. The representative size

gradation of the accumulated sediment was computed

to be 60 percent clay, 28 percent silt, and 12 percent

sand.

Unit Weight Analyses

The dry unit weights of all collected samples listed in

Table 4-1 were used in deriving a representative unit

weight for the total reservoir sediment accumulation.

The graphs in Figure 4-32 relating depth with unit

weight were used as guides to estimate the unit weights

adjusted for compaction since 1935. A weighting

process similar to that applied in determining the

representative particle size gradation was used to

determine the representative unit weight. This

procedure gave a unit weight of about 60 pounds per

cubic foot.

The unit weight was also determined by the procedure

outlined in the paper of Lara and Pemberton.52 An

initial unit weight of 47 pounds per cubic foot was

computed with this procedure assuming the sediments

are always submerged and using the representative

particle size gradations previously determined for clay,

silt, and sand. The procedure by Mi1ler53 was used to

estimate the unit weight after 30 years of consolidation

which also gave a value of 60 pounds per cubic foot.

Additional aspects of the unit weight and other

sediment property analyses are discussed in the

preceding section, Part 4.

Sedimentation Data Summary

A special summary has been prepared in Table 5-3

listing sediment data that were compiled for Lake

Mead. It includes data from both the 1948-49 and

1963-64 surveys.

' Brune, G. M., "Trap Efficiency of Reservoirs," Am. Geophysical Union Trans., Vol. 34, No. 3, pp 407-418,

1953.

5-2 Lara, J. M., and Pemberton, E. L., "Initial Unit Weight of Deposited Sediments," Proc. of the Federal

Inter-Agency Sedimentation Conf., 1963, U.S. Dept. of Agriculture, Misc. PubI. No. 970, pp 818-845, June 1965.

Miller, C. R., "Determination of the Unit Weight of Sediment for Use in Sediment Volume Computations,"

Bureau of Reclamation Report, 7 p, February 1953.

166
Table 5-3

RESERVOIR SEDIMENT

DATA SUMMARY LAKE MEAD (HOOVER DAM)

NAME OF RESERVOIR

DATA SHEET NO.

- 1. OWNER tnterior . Bureau of Reclamation 2. STREAM Colorado 3. STATE Nevada - Arizona

< 4. SEC. 29 TWP. T22S RANGE R65E 5. NEAREST P 0 Boulder City 6NE 6. COUNTY Clark-Mohave

7. LAT 36' 01 ' "LONG. 114' 44' " 8. TOP-OF DAM ELEVATION 12321/ 9. SPILLWAY CREST ELEV. 1221.4 2/

- 10. STORAGE 11. ELEVATION 12. ORIGINAL 13. ORIGINAL 14. GROSS STORAGE, 15. DATE

ALLOCATION TOP OF POOL SURFACE AREA. ACRES CAPACITY. ACREFEE1 ACREFEET STORAGE BEGAN

a. FLOOD CONTROL 1229 162,600 1,587,000 32,471,000

b.MULTIPLE USE / 1219.61 156,600 27,661,000 30,884,000 Feb. 1, 1935

> c. POWER

d. WATER SUPPLY

________________ _________________ ________________ _________________

16. DATE NOR.

MAL OPER. BEGAr

a. IRRIGATION

t. CONSERVATION ________________ __________________

g. INACTIVE 895 33,400 3,223,000 3,223,000 Mar. 1, 1936

17. LENGTH OF RESERVOIR 152 4/ MILES'AV. WIDTH OF RESERVOIR 1.65 MILES

18. TOTAL DRAINAGE AREA 167,800 SQ. MI. 22. MEAN ANNUAL PRECIPITATION 10 / INCHES

19. NET SEDIMENT CONTRIBUTING AREA 167,600 ./ SQ. MI. 23. MEAN ANNUAL RUNOFF 1.30 INCHES

20. LENGTH MILES AV. WIDTH MILES 24. MEAN ANNUAL RUNOFF 11,610,000 l AC-FT.

21. MAX. ELEV. 14,400 MLN._ELEV. 640 25, ANNUAL TEMP MEAN RANGE

26 DATE OP 27. 28. 29. TYPE OF 30.NO.OF RANGES 31. SURFACE 32. CAPACITY, 33. C/I. RATIO,

SURVEY ACCL. SURVEY OR CONTOUR INT. AREA, ACRES ACRE-FEET 8/ AC.-FT.PER AC..FT.

2-1.35 - - (D) 10 ft. 163,000 32,471,000 2.80

9-30-48 13.7 13.7 (D) 10 ft. 163,000 31,047,000 2.67

10.14.64 16.0 29.7 (D) 10 ft. 163,000 29,755,000 2.56

26. DATE OF ANNUAL 35. PERIOD WATER INFLOW, ACRE-FEET 36. WATER INFL. TO DATE, AC-FT.

SURVEY PRECIPITATION a. MEAN ANNUAL b. MAX. ANNUAL c. PERIOD TOTAL a. MEAN ANNUAL b. TOTAL TO DATE

9.3048 12,526,000 17,260,000 175,362,000 12,526,000 175,362,000

10.14.64 10,083,000 18,160,000 161,335,000 11,610,000 336,697,000

>.

26. DATE OF 37 / PERIOD CAPACITY LOSS, ACRE-FEET 38. TOTAL SED DEPOSITS TO DATE, ACRE-FEET

SURVEY a. PERIOD TOTAL b. AV. ANNUAL c.PER SQ. MI-YEAR aTOTAL TO DATE b. AV. ANNUAL C. PER SQ. MI.YEAR

9.30-48 1,424,000 104,000 0.621 1,424,000 104,000 0.621

10.14.64 1,292,000 80,750 0.482 2,716,000 91,450 0.546

26. DATE OF 39. AV. DRY WOT., 40.SED.DEP,.TONSPERSQ.MI.-YR. 41.STORAGE LOSS. PCT. 42. SED. INFLOW, PPM

SURVEY LBS. PER CU. FT. a. PERIOD b. TOTAL TO DATE a.AV.ANN.Ib, TOT.TOQATE a. PERIOD b. TOT.TODATE

9-30-48 65 ./ 879 879 0.320 4.39 8,460 8,460

10.14-64 60 572 714 0.282 8.36 7,700 7,760

167
43. DEPTH DESIGNATION RANGE IN FEET BELOW, AND ABOVE, CREST ELEVATION i/

26. DATE OF

SURVEY 1499-399 I I I 399-299 299-199 199-99 I I

PERCENT OF TOTAL SEDIMENT LOCATED WITHIN DEPTH DESIGNATION

9-30-48 14 21 11 17 21 16

10-14.64 8 14 14 20 28 16

26 DATE OF

REACH DESIGNATION PERCENT OF TOTAL ORIGINAL LENGTH OF RESERVOIR

.

SURVEY 0-10 10-20 20-30 3O-4O 40-50 50-60 60-70 70-80 80-90 I°° _105j _110 -1151 _120j -125

PERCENT OF TOTAL SEDIMENT LOCATED WITHIN REACH DESIGNATION

t., :E MEAD RANGE IN RESERVOIR OPERATION How near Grand Canyon, Arizona

WATER YEAR MAX. ELEV. MIN. ELEV. INFLOW. AC.-FT. WATER YEAR MAX, ELEV, MIN. ELEV. INFLOWS AC.FT.

1936 1025.85 905.2 12,320,000 1952 1201.10 1133.24 18,160,000

1937 1102.90 1021.90 12,410,000 1953 1168.96 1145.78 8,879,000

1938 1173.90 1094.65 15,630,000 1954 1145.74 1105.40 6,229,000

1939 1183.45 1156.10 9,618,000 1955 1106.70 1089.47 7,580,000

1940 1182.2 1164.2 7,435,000 1956 1116.98 1083.23 8,860,000

1941 1220.45 1166.75 16,940,000 1957 1184.07 1089.63 17,500,000

1942 1213.45 1171.05 17,260,000 1958 1205.89 1161.00 14,550,000

1943 1202.41 1176.70 11,430,000 1959 1185.82 1167.28 6,935,000

1944 1200.35 1157.20 13,530,000 1960 1184.21 1162.99 9,584,000

1945 1182.49 1146.55 11,870,000 1961 1165.12 1152.90 7,050,000

1946 1164.30 1146.50 9,089,000 1962 1204.18 1153.14 15,250,000

1947 1180.24 1133.91 13,740,000 1963 1193.14 1136.88 2,742,000

1948 1192.79 1154.46 13,870,000 1964 1136.84 1088.09 2,727,000

1949 1196.61 1145.50 14,370,000 1965 1129.74 1087.99 10,980,000

1950 1177.54 1149.95 11,080,000 1966 1133.84 1127.20 8,328,000

1951 1168.97 1141.19 9,839,000 1967 8,257,000

46. - ELEVATION-AREA-CAPACITY DATA __________ __________ __________

ELEVATION AREA CAPACITY ELEVATION AREA CAPACITY ELEVATION AREA CAPACITY

920 34,600 3,172,112 1120 97,300 15,737,447

740 2,100 10,599 940 39,100 3,909,899 1140 105,900 17 770 850

760 5,200 88,619 960 44,200 4,741,892 1160 118,700 20:007,828

780 7,200 212,321 980 49,100 5,675,145 1180 132,300 22519668

800 12,300 395,&54 1000 54,800 6,710,590 1200 144,900 25 ' 294' 558

820 16,200 684,047 1020 61,200 7,871,659 1220 157,100 28 ' 316' 731

840 19,600 1,039,199 1040 67,500 9,157,105 1229 162,700 29 ' 755 ' 371

860 23,300 1,469,036 1060 75,100 10,581,403

880 26,300 1,966,061 1080 82,200 12,154,669

900 29,900 2,525,433 1100 89,500 13,869,388

47.REMARKS AND REFERENCES

See supplemental sheet

48. AGENCY MAKING SURVE Y U.S. Coast and Geodetic Survey

49. AGENCY SUPPLYING DATA Bureau of Reclamation 50. DATE July 1969

168
Data Sheet No.

SUPPLEMENT TO RESERVOIR SEDIMENT

DATA SUMMARY-LAKE MEAD

47. REMARKS AND REFERENCES

All elevations refer to powerhouse datum. Add 0.55 foot to convert to datum of 1929, leveling at 1935.

2Spillway gates in raised position.

Flood control, municipal and industrial, irrigation, and power use. Originally (1935) the top of the multiple-use

pool was at elevation 1213.17 feet above which 2,500,000 acre-feet were provided for flood control storage

space. Flood control regulations for Hoover Dam and Lake Mead published in the Federal Register, Vol. 33, No.

147, July 30, 1968, pages 10,801-10,802, revised the flood control space to 1.5 million acre-feet. Elevation

1219.61 feet is the reservoir level established from the 1964 survey to provide the currently required 1.5 million

acre-feet of flood control space. This elevation will change with each subsequent survey in order to maintain the

fixed flood control storage allocation.

4Colorado River about 121 miles; Overton Arm about 31 miles.

Not adjusted for numerous small reservoirs.

Estimated for six states in Colorado River Basin.

7Colorado River at Grand Canyon, 1935-64 (30 years).

8Capacities at elevation 1229 feet.

9Based on measured and estimated sediment inflow of 2 billion tons in 13.7 years.

0 Based on elevation 1229 feet.

169

PART 6-SUMMARY AND

CONCLUSIONS

The 1963-64 survey of Lake Mead was made primarily

to determine the capacity of the reservoir. Details of

the field surveying procedures and results of the

hydrographic and geodetic surveys are described in this

report. An explanation is given of the field techniques

and equipment used to sample the reservoir sediment

deposits and a description is included of each

laboratory test made of the samples. The report also

presents the results of the analytical methods used to

study the nearly 30 years of sediment accumulations in

Lake Mead.

A geodetic survey was made in 1963 to determine the

amount of vertical movement that occurred in the

lands under and surrounding the lake because of the

water impounded by the reservoir. With the reservoir

full, this water would weigh about 40 billion tons.

Comparing the relevel data of the 1963-64 survey

showed the reservoir area generally made a rebound

since the 1948-49 survey (Figure 2-3, page 35). This

means the vertical deformation was generally in a

positive direction or there was a rise in the land

surface, It varied from no rise at all to 40 mm or

slightly greater than 1-1/2 inches in the Boulder and

Virgin Basins. During the 1935 and 1963-64 interval,

the geodetic survey showed most of the area subsided

or lowered except for the upper arms on both the

Colorado and Virgin Rivers (Figure 2-2, page 34).The

dam subsided an average of 118 mm during this period.

The maximum subsidence, over 700 mm or nearly 28

inches, occurred in the vicinity of Las Vegas Valley.

This is believed due to the removal of ground water

from underlying formations. From the results of the

geodetic survey, it was concluded there was no

appreciable change in reservoir capacity since 1935

because of any subsidence or rebound in the reservoir

basin.

The Region 3 office of the Bureau of Reclamation

suggests that the sheet layout for future surveys of

Lake Mead be marked with 5-minute quadrangle sheets

so that the contours on these quadrangles can be

planimetered and checked and closed by a geodetic

table of 5-minute quadrangle areas. This would also

permit making comparisons to the Soil Conservation

Service survey.

A hydrographic survey of Lake Mead was started in

July 1963 and completed in October of the next year.

The object of this survey was to gather enough data to

trace the reservoir contours at 10-foot intervals up to

an elevation of 1230 feet. Photogrammetric surveys

were made of the Overton Arm, Grand Bay, and Pierce

Basins where it was necessary to determine the change

in capacity or movement of the sediment deposits

above elevation 1150 feet since the 1948-49 survey.

For the underwater reservoir areas, sonar soundings

were made from a launch to determine lake depths

along predetermined range lines in the Colorado River

and Overton Arm Basins. In lower Granite Gorge, the

uppermost basin on the Colorado River, 174 cross

sections were established for the 1948-49 survey. All

these cross sections were reprofiled. Important to these

surveys was the establishment of vertical and

horizontal control. Vertical control was maintained by

referencing the levels to reservoir forebay elevation

gage at Hoover Dam. Because the lake level decreased

continually, it was necessary to install a mobile gage

system. These gages facilitated the survey because they

could be moved to new locations as necessary. In the

Lower Granite Gorge area, levels were tied to existing

bench marks in the vicinity. For horizontal control, the

same triangulation stations used in the 1948-49 survey

were reestablished wherever possible for the 1963-64

survey.

Records of the reservoir gages observed during the

1963-64 survey indicated that seiches, tides, wind, and

slope had negligible effect on the horizontality of the

lake surface. Based upon these findings which agree

with those of the 1948-49 survey, the Coast and

Geodetic Survey recommended that future surveys of

Lake Mead disregard these actions.

Sediment samples were collected at 17 reservoir

locations (Figure 4-1, page 77).The sampling was done

in two separate phases to determine certain physical

and chemical characteristics of the accumulated

sediments. The first sampling work was done in the fall

of 1963. The objective was to use standard drilling

equipment to obtain extensive undisturbed drive

samples of the delta formation. A dry delta area in

Pierce Basin was selected as the test site designated

Drill Hole No. 1 (Figure 4-1, page 77). The sampling

operation was unique in that a helicopter was needed

to transport personnel and equipment to the remote

site. It took the helicopter 42 flights and nearly 8

hours to move the men and material cumulatively

weighing about 18,000 pounds. The drill rig setup

(Figure 4-8, page 87) allowed control of the sampling

to a 207-foot depth in the delta formation. The second

sampling phase was carried out a year later in the fall

of 1964. The objective was to collect piston-core

samples of the underwater reservoir deposits and to use

a nuclear gamma probe to get readings of the density

and consolidation effects of the deposits at 16

individual sites. Floating equipment (Figure 4-5, page

171
82) was used to obtain sampling data by both the

piston core and gamma probe.

Upon reducing the collected field data, reservoir area

and capacity tables (Table 3-5, page 66 and Table 3-6,

page 67) were generated by an electronic computer and

the results plotted graphically in Figure 3-7, page 71.

The capacity of Lake Mead now is 29,755,000

acre-feet and the reservoir surface 162,700 acres at

elevation 1229 feet.

The measured sediment accumulations in Lake Mead

amounted to 2,716,000 acre-feet since the dam was

closed in 1935. This gives an average inflow rate of

91,450 acre-feet per year. An annual sediment yield

rate of 0.546 acre-foot per square mile was indicated

from this survey. Representative size gradation of the

accumulated sediment was computed to be 60 percent

clay, 28 percent silt, and 12 percent sand. A unit

weight of 60 pounds per cubic foot was determined as

representative of the deposited sediments from

analyses of the collected samples. The reservoir trap

efficiency is judged to be 100 percent for practical

purposes. Other sedimentation data are summarized iii

Table 5-3, page 167. The longitudinal distribution of

the sediments is depicted by the profiles in Figure 5-3,

page 155. An idea of how the sediments deposited

laterally can be had by studying the cross sections

plotted in Figure 5-2, pages 143 to 153.

With the closure of Glen Canyon Dam on the Colorado

River about 370 miles upstream, the life of Lake Mead

is estimated to be increased to 500 years.

172
7-1750 0-70)

}0,,,o,ooi R, meon

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CONS.'FFal:ON FACO'ORC--BRFIlS TO MFTRIC UNiTJ OF ill PFIv'tfFt

Thi followinp so'icersion fealor alopted 'y the Bureau of Fe'larnat'on ho published j the Ame-ican Is iefy for

'Sestin7 and Materials lASTS" Meric factice Guid, F 380-48) exept that additional faAors )") commonly used in

tin Bureau have been added. Furtcer discussion of oefinitiono of quanCtios and ants is givon in "h ASTIS Ue'ric

Pra-Oce Guiae.

Tbo metric units and onversion fa'-tors aditel by the ASTM are barad on the 'Overnational Pji"em of Un7ta (deionated

SI for Iysterne In"ernational d'Unites), ilxed by the International Committee for Weights and SI eas ore tbi. system is

also tcn wn as tha Giorgi or MKIA (meter-kilogram (mass)-ra'-ono-ampere) system. This "y:tern tar buns ad pted by

th International Organization for 5andardization in ISO Recomnendation R-31.

The metrIc technical un't of force is the kilogram-force; this is the force wt ich, when applied to a booy having

mass f 1 kg, gives it an acceleration of 0. 80865 m/se-/s€c, the standard acceler ni n of free fall towerd the unrths

center for sea level at 45 deg latitude. The iretric unit of force in It unit. is the n aton (181, which is defined as

that Mccc which, eden applied to a body hav'ng a mass of 1 kg, give it an acceleration of] m/se/se. 0hee units

mmd be distinguished from the (ianon"tant) lunsi weight of a body having a mao of 1 kg; 1hat is, the weight of a

body i that force with which a body in attracted to tbo ear5h and is equal to th mass of a body maltilied by the

acceleration due to gravity. Uowecer, tecau-e it is general prantice to use "pound" rather than the teinnically

correal term "pound-force, " the term kiogran-" (or derived ma salt) has been used In this guide instead of kiogran- -

force' n exores 'ing the conversion factors for forces. The newton unit of force will find ianreasing use, and is

essential in SI units.

WI-crc approximate or nominal Tnnglish unit are used to exoress a value or range of value, the concerted metric units

in parentheses are also approximate or nominal. Whe-e orecise Enjlish units are aned, the concocted metric unis

are excresed as equally significant value.

Table I

UANTITIES AND UNITS OF SPACE

Multiply By To obtain

LENGTH

Mid 25.4 (exactly) Micron

Inches 25.4 (exactly) Millimeters

2. 54 (exactly)* Centimeters

Feet 30. 48 (exactly) Centimeters

0. 3048 (exactly)* Meters

0. 0003048 (exactly)* . . .

. Kilometers

Yards 0 9144 (exactly) Meters

Miles (statute) 1,609.344 (exactly)* Meters

1. 609344 (exactly) Kilometers -

Square inches 6. 4516 (exactly) Square centimeters

Square feet 929. Q3*

0. 092903 Square meters

Square yards 0. 836127 Square meters

Acres 0. 40469* Hectares

4,046.9* Square meters

0. 0040469* Square kilometers

Square miles 2. 58999 Square kilometers

VOLUME

Cubic inches 16. 3871 Cubic centimeters

Cubic feet 0. 0283168 Cubic meters

Cubic yards 0. 764555 Cubic meters

CAPACITY

Fluid ounces (IT. S.) . . 29. 5737 Cubic centimeters

29. 5729 Milliliters

LIquid pints (U. S.) . . 0. 473179 Cubic decimeters

0. 473166 Liters

Quarts (U.S.) 946. 358* Cubic centimeters 0. 948331* Liters

Gallons (U.S.) 3,785.43* ubic centimeters

3. 78543 Cubic decimeters

3, 78533 Liters

0. 00378543* Cubic meters Gallons (U. K.) 4. 54609 Cubic decimeters

4. 54596 Liters Cubic feet 28. 3160 ters Cubic yards 764. 55* Liters

Acre-feet 1,233. 5* Cubic meters

1,233,500* Liters
Table It

QU/ TITlES AND UNITS OF MECHANICS

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Mtritiplc By To obtain

Gratne (1/7, 00 N) ......, 61, 73891 (ruactly) MIllIgrams

Trov ounces (483 graIns) 31. 1335 Grams

Ounces (snip) 28. 3495 Grams

Pounds (av7( 0. 45359237 (esacily) Kilcçramo

Sbcrt tons (7,30•3 /51 907. 185 tiperams

0.907185 Metric tons

Long Ions ll. . ,... .1,018.00 .iiperarus

Pounds pcr square mc" 3.0 10302 Kilograms per square centimeter

0. 689426 Newtons per square centImeter

P00505 per square fool 4.88247 liogran,s per square meter

________________ 47. 8803 NewtOns per sasae meter

SS/VOLiflvIE )DENSITY)

Ounces per cubic nor 1. 77359 Grams per cubic centimeter

Pounos per cubic trot 18. 0186 ilograms per cubic meter

0.018:1 15 Grams per cubic rusttmeter

Tons (long) per cubic iGro . . . ,,,i,3287'l Grams per cubic centimeter

Ounces per gsllor (U. S. ) '7. 4883 Grams per lIter

Ounces per gallon (U.K.) 6.2362 Grams per liter

Poumts per gallon (17, 5.) 119, 829 Grams par liter

Pousdo per gallon (U. K,) 93. 773 Grams per liter

BENDING MOMENT OR TORQUE

lnch-pou to 0.011821,..... , Meter-kIlograms

1. 12885 s 106 Centtmetar-dpees

Foot-pcunus . 0. 138255.. ,, Meter-kIlograms

1.358820 10' Centtmeter-dynes

Fosl-pcucds per Inch 5. 4431 Centtmeter-tdlograms per centimeter

Ounce-tscbes.,..,.., .,,, '/2, 008 .,,..,... .. Gram-centimeters

VELOCITY

Feet per ueconr...,.,, 30.48 (euactly) Centimeters per second

0.3048 (etsoctiy)* Meters per second

Keel per year 0.965823 a t0-° Centimeters per second

Mtles per hour 1.809344 (exactly) Kilorsaters per hour

0. 44704 (ouactly( Meters per second

ACCELERATION*

Feet per yecon7° 0. 30480 Meters per second2 -

Cubic teen per seccsl (secondfeet) 0. 028317 Cubic meters per second

i'ublr teat per minute 0.4719 Liters per second

Gallons (U, SI per minute 0.08300 Liters per second

Pounds 0.453010* ....,....Kticgrams

,. 4d: Newtons

_________ 4..,i437s10"5 Dynes

By Tc oh talc

WORK AND ENERGYC

Brlttsh thermal units (Mu) .0. 252* ,,,,,,,,,,V.tiogrtm calories

Stu per pound : : : ' - . 220 0-zacCi cc pus

Foot-pour' l.3lb6'° - -

Horsepower 745. 700 Watts

Btu per hour 0. 293071 Watts

Foot-pounds per second 1.35582 ....,.., , Watts ______________

- HEAT TRANSFER

Mu in. /hr ft2 deg F )k,

thermal conductivity) 1. 442

240

Mtlllwatts/cm leg C

l h l C

h ' f "

0.1

1 4880*

Kgca / sm a9

Btu ft/ o t de F K l h 3 l C

Mu/hr ftl le (C thermal

. ........ .. g ca m/ r m eg

g ,

conductance) 0. 568

2

MtllIwaito/c.' leg C

al h ' d C

Deg F tsr ft0/Btu (R, thermal

4. 88 Kg c / r rn eg

resistance) 1.761 Deg C crn"/mllliwatt

Btu/lb dog F Ic, heat capacIty) . . . 4. 1868 J/g leg C

Big/lb deg F 1.000* Cal/gram leg C

Ft2/hr (thermal dtffustvlty( 0. 2531 ........

e

.. Cgo"/oac

o.09290 M /h,_,

WATER VAPOR TRANSRD85ION ______________

Grains/hr ft2 (water vapor

transmission) 16.7 Grams/SI hr m5'

PermS (persseance( 0.659 MetrIc permu

Perrn-Inches (permeability) .,. .. 1.67 MetrIc perm-centtmetsra

Table III

OTHER QUANTITIES AND UNITS

Multiply By To ohWin

Cubic feet per square foot per

day (seepage) 304.3* titers per square meter per ray

Pound-seconds per square foot

(vtucoalty( 4.8824*, Kilogram second per square meter

Square feet per second (viscosity). . 0. 092903* Square meters per second

FahrenheIt degrees (chasge)* 5/9 exactly Celsius Or Kelvin degrees (changa(

Volts per soil 0,C3937..,..,.., Ktlovolts per milllmeter

Lumens per square foot (footcandles) 10.764.,, Lumens per square meter

Ohm-circular miis per foot 0.001662 Ohm-square millImeters per meter

Mtliicurtes per cubic foot ..., 35. 3147* .,,.,., Millicurlea per cubIc meter

Milliamps per square foot 10. 7639* Mtiiamps per square meter

Gallons per square yard 4.5272180 Liters per square meter

Pounds per Inch 0. 17858. .,.., Kilograms per centImeter -

GPO 832.603
ABSTRACT ABSTRACT

The 1963-64 Lake Mead survey was run to compute the reservoir capacity. Results of the

geodetic and hydrographic surveys and sediment sampling equipment are described. The

geodetic survey showed Hoover Dam subsided an average of 118 mm since 1935. Sonic

sounding, photogrammetry. and cross-sectional profiling methods were used to run the

hydrographic survey. Reservoir area and capacity tables were generated using an electronic

computer. The present take capacity is 29,755,000 acre-ft and the reservoir surface area is

162,700 acres at elevation 1229 ft. 2,720,000-acre-ft of sediments accumulated in the lake

since 1935. A unit weight of 60 lb/cu ft was determined representative of the deposited

sediments. Samples were collected from the major basins with a piston core sampler. A gamma

probe was used to measure in situ wet bulk densities. Special sampling with a drill rig was

conducted in Pierce Basin representing the sediment accumulation in the delta area. The

reservoir trap efficiency is judged to be 100%.

The 1963-64 Lake Mead survey was run to compute the reservoir capacity. Results of the

geodetic and hydrographic surveys and sediment sampling equipment are described, The

geodetic survey showed Hoover Dam subsided an average of 118 mm since 1935. Sonic

sounding, photogrammetry, and cross-sectional profiling methods were used to run the

hydrographic survey. Reservoir area and capacity tables were generated using an electronic

computer. The present lake capacity is 29,755,000 acre-ft and the reservoir surface area is

162,700 acres at elevation 1229 ft. 2,720,000-acre-ft of sediments accumulated in the lake

since 1935. A unit weight of 60 lb/cu ft was determined representative of the deposited

sediments. Samples were collected from the major basins with a piston core sampler. A gamma

probe was used to measure in situ wet bulk densities. Special sampling with a drill rig was

conducted in Pierce Basin representing the sediment accumulation in the delta area. The

reservoir trap efficiency is judged to be 100%.

ABSTRACT ABSTRACT

The 1963-64 Lake Mead survey was run to compute the reservoir capacity. Results of the : The 1963-64 Lake Mead survey was run to compute the reservoir capacity. Results of the

geodetic and hydrographic surveys and sediment sampling equipment are described. The : geodetic and hydrographic surveys and sediment sampling equipment are described. The

geodetic survey showed Hoover Dam subsided an average of 118 mm since 1935. Sonic geodetic survey showed Hoover Dam subsided an average of 118 mm since 1935. Sonic

sounding, photogrammetry, and cross-sectional profiling methods were used to run the : sounding, photogrammetry, and cross-sectional profiling methods were used to run the

hydrographic survey. Reservoir area and capacity tables were generated using an electronic hydrographic survey. Reservoir area and capacity tables were generated using an electronic

computer. The present lake capacity is 29,755,000 acre-ft and the reservoir surface area is computer. The present lake capacity is 29,755,000 acre-ft and the reservoir surface area is

162,700 acres at elevation 1229 ft. 2,720,000-acre-ft of sediments accumulated in the lake 162,700 acres at elevation 1229 ft. 2,720,000-acre-ft of sediments accumulated in the lake

since 1935. A unit weight of 60 lb/cu ft was determined representative of the deposited since 1935. A unit weight of 60 lb/cu ft was determined representative of the deposited

sediments. Samples were collected from the major basins with a piston core sampler. A gamma sediments. Samples were collected from the major basins with a piston core sampler. A gamma

probe was used to measure in situ wet bulk densities. Special sampling with a drill rig was probe was used to measure in situ wet bulk densities. Special sampling with a drill rig was

conducted in Pierce Basin representing the sediment accumulation in the delta area. The conducted in Pierce Basin representing the sediment accumulation in the delta area. The

reservoir trap efficiency is judged to be 100%. :

reservoir trap efficiency is judged to be 100%.
A EC-OCE-70-21

Lara, J M and Sanders, J

THE 1963-64 LAKE MEAD SURVEY

Bur Reclam Rep REC-OCE-70-21, Aug 1970. Bureau of Reclamation, Denver

and Boulder City, 162 p, 52 fig 16 tab, 12 ref

DESCRIPTORS --/ reservoir surveys! reservoir silting! aggradation! core drilling! geodetic

surveys! first order surveys! land subsidence! gamma rays! rebound! hydrographic surveys!

sounding! photogrammetry/ thalweg/ topographic mapping! sediment sampling!

sedimentation! trap efficiency! fluvial hydraulics! sediment transport! physical properties!

watersheds (basins)! unit weight

IDENTIFIERS--! reservoir capacity! gamma probes! Arizona-Nevada! Lake Mead

REC-OCE-70-21

Lara, .1 M and Sanders, J I

THE 1963-64 LAKE MEAD SURVEY

Bur Reclam Rep REC-OCE-70-21, Aug 1970. Bureau of Reclamation, Denver

and Boulder City, 162 p, 52 fig, 16 tab, 12 ref

DESCRIPTORS-i *reservoir surveys! reservoir silting! aggradation,' core drilling! geodeti

surveys! first order surveys! land subsidence! gamma rays! rebound! *hydrographic surveys,

sounding! photogrammetry! thalweg! topographic mapping! sediment sampling,

"sedimentation! trap efficiency! fluvial hydraulics! sediment transport! "physical properties,

watersheds Ibasins)! unit weight

IDENTIFIERS--/ reservoir capacity! gamma probes/Arizona-Nevada! Lake Mead

REC-OCE-70-21

Lara, J M and Sanders, J I

THE 1963-64 LAKE MEAD SURVEY

Bur Reclam Rep REC-OCE-70-21, Aug 1970. Bureau of Reclamation, Denver

and Boulder City, 162 p, 52 fig, 16 tab, 12 ref

DESCRIPTORS--! reservoir surveys! "reservoir silting! aggradation! core drilling! "geodetic

surveys! first order surveys! land subsidence! gamma rays! rebound! "hydrographic surveys!

sounding! photogrammetry/ thalweg! topographic mapping! sediment sampling!

'sedimentation! trap efficiency! fluvial hydraulics! sediment transport! "physical properties!

watersheds (basins)! unit weight

IDENTIFIERS--! reservoir capacity! gamma probes! Arizona-Nevada! Lake Mead

REC-OCE-70-21

Lara, J M and Sanders, J I

THE 1963-64 LAKE MEAD SURVEY

Bur Reclam Rep REC-OCE-70-21, Aug 1970. Bureau of Reclamation, Denver

and Boulder City, 162 p, 52 fig, 16 tab, 12 ref

DESCRIPTORS--! "reservoir surveys! "reservoir silting! aggradation! core drilling! "geodetic

surveys! first order surveys! land subsidence! gamma rays! rebound! "hydrographic surveys!

sounding! photogrammetry/ thalweg/ topographic mapping! sediment sampling!

"sedimentation! trap efficiency! fluvia I hydraulics! sad iment transport! "physical properties!

watersheds (basins)! unit weight

IDENTIFIERS--! reservoir capacity! gamma probes/ Arizona-Nevada! Lake Mead

I