U.S. Department of the Interior 

Bureau of Reclamation 

Technical Service Center 

Denver, Colorado February 2008 

2001 Lake Mead 

Sedimentation Survey 
U.S. Department of the Interior 

Bureau of Reclamation 

Technical Service Center 

Water Resources Services Division 

Sedimentation and River Hydraulics Group 

Denver, Colorado February 2008 

2001 Lake Mead 

Sedimentation Survey 

prepared by 

Ronald L. Ferrari 
ACKNOWLEDGMENTS

Bureau of Reclamation’s (Reclamation) Sedimentation and River Hydraulics 

(Sedimentation) Group of the Technical Service Center (TSC) was the technical field 

lead and conducted the analysis for this report. Kevin Fagot, Lower Colorado Region 

(LCR), coordinated the funding for collection and initial analysis of the extensive data 

sets. Ronald Ferrari and Kent Collins, Sedimentation Group, and Steve Belew, LCR, 

conducted the underwater data collection. Ron Ferrari processed the bathymetric survey 

information into x,y,z data sets. Steve Belew completed the extensive topographic 

mapping from these data sets. Ron Simms, LCR, coordinated several study meetings and 

the 2001 aerial collection for a portion of the upper reservoir area. Ron Ferrari completed 

the data processing to generate the area-capacity and sedimentation computations 

presented in this report. Kent Collins of the Sedimentation Group performed the 

technical and editorial peer review of this documentation.

Mission Statements 

The mission of the Department of the Interior is to protect and 

provide access to our Nation’s natural and cultural heritage and 

honor our trust responsibilities to Indian Tribes and our 

commitments to island communities. 

The mission of the Bureau of Reclamation is to manage, develop, 

and protect water and related resources in an environmentally and 

economically sound manner in the interest of the American public. 

Reclamation Report 

This report was produced by the Bureau of Reclamation’s Sedimentation and 

River Hydraulics Group (Mail Code 86-68540), PO Box 25007, Denver, 

Colorado 80225-0007. http://www.usbr.gov/pmts/sediment/ 

Disclaimer 

No warranty is expressed or implied regarding the usefulness or completeness of 

the information contained in this report. References to commercial products do 

not imply endorsement by the Bureau of Reclamation and may not be used for 

advertising or promotional purposes. 

Cover – Multibeam data topographic image looking downstream towards Hoover 

Dam (developed by Steve Belew, LCR). 

iii

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12. DISTRIBUTION/AVAILABILITY STATEMENT 

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14. ABSTRACT 

The 2001 Lake Mead survey measured an increase in reservoir capacity of 219,150 acre-feet since the 1963-64 (1963) reservoir survey. The 

increased capacity was attributed to a significant decrease of sediment inflow due to the March 1963 closure of Glen Canyon Dam, located 

upstream of Lake Mead, and compaction of the previous sediment deposition. Since Hoover Dam closure in 1935, the 2001 study measured 

2,402,770 acre-feet of sediment deposition compared to the 1963 survey result of 2,621,920 acre-feet. As of September 2001, at water surface 

elevation 1,229.0, the surface area was 162,548 acres with a total capacity of 29,979,010 acre-feet. The 2001 study measured an average 

annual rate of sediment accumulation, since dam closure, of 36,024 acre-feet compared to the 1963 average annual rate of 88,028 acre-feet. 

Since the 1963 closure of Glen Canyon Dam and the significant trapping of the Colorado River sediments within Lake Powell, the Lake Mead 

average sediment inflow rate has significantly decreased to an estimated rate of less than 10,000 acre-feet per year. 

Reclamation’s Sedimentation Group surveyed Lake Mead in 2001 to develop a storage-elevation relationship. The underwater survey, 

conducted over 22 days between April 5 and May 16, used a multibeam depth sounder interfaced with a global positioning system (GPS) that 

gave continuous sounding positions throughout the reservoir covered by the survey vessel. Updated topography of Lake Mead was developed 

by combining the 2001 survey data and original digital data from the U.S. Geological Survey quadrangle (USGS quad). A complete

hydrographic survey, above and below water, would provide the most accurate reservoir topography. However, cost prohibits or delays such 

data collections. Over the years limited budgets have affected survey frequencies resulting in limited knowledge of our nation’s reservoirs. 

Reconnaissance techniques combine streamlined collection and analysis procedures with modern instrumentation to produce quality results in 

a timely and effective manner by surveying only where the majority of the sediment accumulates. The technique requires original digital 

reservoir topography to guide the survey vessel along the sediment deposit areas and for computing the updated reservoir information. 

Reconnaissance techniques for the 2001 survey of Lake Mead greatly reduced collection and analysis costs, but still produced quality results. 

The reconnaissance techniques presented in this report illustrate how to update the area and capacity on reservoirs like Lake Mead more 

frequently, but at a much lower cost than a complete hydrographic survey.

15. SUBJECT TERMS 

reservoir area and capacity/ sedimentation/ surveys/ GPS/ multibeam sounders/ reconnaissance techniques/ contour area/ Hoover 

Dam, Lake Mead 

16. SECURITY CLASSIFICATION OF: 19a. NAME OF RESPONSIBLE PERSON 

a. REPORT b. ABSTRACT a. THIS PAGE 

17. LIMITATION 

OF ABSTRACT

18. NUMBER 

OF PAGES 

19b. TELEPHONE NUMBER (Include area code)

Standard Form 298 (Rev. 8/98) 

Prescribed by ANSI Std. Z39.18 
iv
v

Table of Contents 

Page 

2001 Lake Mead............................................................................................................................... 1 

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

Dam and Reservoir........................................................................................................................... 1 

Cofferdams................................................................................................................................ 5 

Drainage Area ........................................................................................................................... 6 

Summary and Conclusions............................................................................................................... 7 

Reservoir Operations...................................................................................................................... 11 

Purpose of Reservoir Surveys ........................................................................................................ 12 

Hydrographic Survey Equipment and Method............................................................................... 18 

Methodology ........................................................................................................................... 22 

GPS Technology ..................................................................................................................... 23 

Depth Measurements............................................................................................................... 25 

Additional Studies and Information ............................................................................................... 26 

Original Topography of Lake Mead........................................................................................ 26

1948-49 Lake Mead Sedimentation Survey ............................................................................ 33 

1963-64 (1963) Lake Mead Sedimentation Survey................................................................. 34 

1998 Sediment Sampling ........................................................................................................ 35 

Biological Monitoring Cross Sections .................................................................................... 35 

2000 Preliminary Meeting....................................................................................................... 36 

2001 Lake Mead Field Survey ....................................................................................................... 37

2001 Lake Mead Analysis.............................................................................................................. 43 

Topographic Processing by LCR ............................................................................................ 43 

Generating the 1935 Topographic Surfaces ..................................................................... 44 

Generating the 2001 Surfaces by LCR............................................................................. 45 

LCR Volume and Sediment Computations...................................................................... 46

Generating the 2001 Surface Areas by the Sedimentation Group........................................... 49 

Upper Reservoir Delta Deposition and Formation........................................................... 57 

2001 Measured Depth Analysis ....................................................................................... 59 

Consolidation of Bottom Sediments ................................................................................ 60 

Summary of Sedimentation Group’s Processing............................................................................ 67 

Reservoir Area and Capacity.......................................................................................................... 77 

2001 Topography Development.............................................................................................. 77 

Development of the Contour Areas and Reservoir Volume.................................................... 77 

2001 Reservoir Sediment Analyses................................................................................................ 78 

References ...................................................................................................................................... 99 

Appendix I.................................................................................................................................... 103

Basins by Map Numbers 

Appendix II .................................................................................................................................. 109 

Depth Measurements 

Appendix III ................................................................................................................................. 113 

 Lake Mead Cross Sections 

Appendix IV................................................................................................................................. 127 

Reservoir Sediment Compaction Analysis 

Appendix V .................................................................................................................................. 133 

Summary of Analysis by TSC 

Appendix VI................................................................................................................................. 145 

 2001 Lake Mead Area and Capacity Tables 

Appendix VII 

 The 2001 Lake Mead Bathymetry Survey 
vi

Index of Figures 

Page 

Figure 1 - Reclamation Dam locations in Nevada............................................................................ 2 

Figure 2 - Hoover Dam and Lake Mead........................................................................................... 2 

Figure 3 - Hoover Dam downstream releases. ................................................................................. 3 

Figure 4 - Hoover Dam intake towers and top of cofferdam............................................................ 4 

Figure 5 - Upstream face of Hoover Dam and four intake towers.................................................... 5 

Figure 6 - Hoover Dam cofferdams.................................................................................................. 6 

Figure 7 - Colorado River drainage area (Dettinger, M.D. 1995). ................................................... 7 

Figure 8 - Profile of reservoir delta formation. .............................................................................. 12 

Figure 9 - Lake Meads’ longitudinal section through the Colorado delta, showing relation of 

bottomset beds to the topset and foreset beds. (USGS, 1960). ............................................. 13 

Figure 10 – Colder Colorado River inflow interface, upper Lake Powell...................................... 14 

Figure 11 - Periods of reported density currents and elevation of sediment surface at Hoover Dam, 

1935 through 1950 (USGS, 1960). ....................................................................................... 15 

Figure 12 - Survey vessel with mounted instrumentation on Jackson Lake, Wyoming................. 19 

Figure 13 - Multibeam collection system....................................................................................... 20 

Figure 14 - Upper end of Lake Mead after significant drop of reservoir content since 2001 survey. 

Exposed Pierce Basin sediment delta, lower right. Grand Bay water body formed by 

sediment dike, top right corner (NASA, Visible Earth, visibleearth.nasa.gov). ................... 22 

Figure 15-Lake Mead Basins, figure 3 from 2001 LCR report. ..................................................... 39 

Figure 16 - 2001 Lake Mead bathymetry data sets, figure 2 from LCR 2001 report. .................... 40 

Figure 17 - B29 Multibeam image from Lake Mead, developed by LCR...................................... 41 

Figure 18 - Map sheet boundaries, figure 4 of 2001 LCR report. .................................................. 44 

Figure 19 -Multibeam data of Colorado River upstream of Hoover Dam...................................... 50 

Figure 20 - Multibeam generated image of Hoover Dam and intake towers.................................. 51 

Figure 21 - Las Vegas Wash longitudinal profile........................................................................... 53 

Figure 22 - Overton longitudinal profile. ....................................................................................... 54 

Figure 23 - Colorado River longitudinal profile............................................................................. 55 

Figure 24 - Reservoir sediment density location zones (1935 to 1948). ........................................ 58 

Figure 25 - Gregg Basin section G-G............................................................................................. 68 

Figure 26 - Gregg Basin section H-H............................................................................................. 69 

Figure 27 - Multibeam data of Navajo Canyon on Lake Powell showing deposition along toe of 

vertical walls......................................................................................................................... 71 

Figure 28 - Lake Mead Area and Capacity Curves. ....................................................................... 95 

Figure 29 - Lake Mead divided by subbasins, LCR 2003 report.................................................. 105 

Figure 30 - Lake Mead divided by submaps, LCR 2003 report. .................................................. 106 

Figure 31 - Location of Lake Mead cross sections....................................................................... 115 

Figure 32 - Gregg Basin section G-G........................................................................................... 116 

Figure 33 - Gregg Basin section H-H........................................................................................... 116 

Figure 34- Temple Bar section I-I................................................................................................ 117 

Figure 35 - Temple Bar section J-J............................................................................................... 117 

Figure 36 - Virgin Basin section K-K .......................................................................................... 118 

Figure 37 - Boulder Canyon section L-L...................................................................................... 118 

Figure 38 - Boulder Basin, section M-M...................................................................................... 119 

Figure 39 - Boulder Basin near dam, section N-N. 1963 survey plotted below 1948. ................ 119 

Figure 40 - Overton Arm, section Q-Q ........................................................................................ 120 

Figure 41 - Overton Arm, section R-R......................................................................................... 120 

Figure 42- Overton Arm, section S-S........................................................................................... 121 

Figure 43 - Overton Arm, section T-T. ........................................................................................ 121 

Figure 44 - Overton Arm, section U-U. ....................................................................................... 122 

Figure 45 - Section 1112. ............................................................................................................. 122 

Figure 46 - Section 67. ................................................................................................................. 123 

Figure 47 - Section 19. ................................................................................................................. 123 
vii

Figure 48 - Section 27. ................................................................................................................. 124 

Figure 49 - Section 26. ................................................................................................................. 124 

Figure 50 - Section 25. ................................................................................................................. 125 

Figure 51 - Section 37. ................................................................................................................. 125 

Index of Tables 

Table 1-1935 Lake Mead Surface Areas (1 of 4). .......................................................................... 29 

Table 2 - LCR computation results. ............................................................................................... 47 

Table 3 - 2001 Lake Mead surface areas (1 of 4)........................................................................... 73 

Table 4 - Reservoir sediment data summary (page 1 of 2)............................................................. 81 

Table 5 - Reservoir sediment summary.......................................................................................... 83 

Table 6 - Sediment analysis by basins, page 1 of 8........................................................................ 85 

Table 7 - Computed Contour Surface Area by Survey................................................................... 93 

Table 8 - Total capacity by basin and year..................................................................................... 97
viii
1

2001 Lake Mead 

Sedimentation Survey 

Abstract 

Reclamation’s Sedimentation Group surveyed Lake Mead in spring 2001 to 

develop a storage-elevation relationship. This report was produced by the 

Sedimentation Group summarizes the 2001 Lake Mead survey results that utilized 

reconnaissance procedures for collection and analysis (Ferrari, 2006). The 2001 

study measured 2,402,770 acre-feet of sediment deposition since closure of 

Hoover Dam and initial filling of Lake Mead in February 1935. The 2001 survey 

measured a 219,150 acre-feet increase in reservoir capacity since the last survey 

of Lake Mead in 1963 (Lara and Sanders, 1970). This study addressed the 

capacity increase phenomenon, concluding the occurrence was due to significant 

reduction of sediment inflow since the 1963 upstream closure of Glen Canyon 

Dam and significant compaction of Lake Mead’s previous measured deposited 

sediments in the lower elevation portions of the reservoir. 

The underwater survey was conducted over 22 days between April 5th and May 

16th of 2001. The survey used a multibeam depth sounder interfaced with GPS 

that provided continuous sounding positions throughout the reservoir covered by 

the survey vessel. Reconnaissance techniques utilized a streamlined collection 

procedure that concentrates on areas of known reservoir sediment accumulation 

from past surveys of Lake Mead and surveys of other similar reservoirs. Updated 

topography of Lake Mead was developed by combining the 2001 survey data with 

the original digital data from the USGS quads. Reconnaissance techniques for the 

2001 survey of Lake Mead greatly reduced collection and analysis costs while 

producing quality results including current area and capacity relationships and 

showing the loss of reservoir capacity due to sediment accumulation.

Dam and Reservoir 

Hoover Dam, on the Arizona-Nevada state line in the Black Canyon of the 

Colorado River, forms Lake Mead located in Clark and Mohave counties about 6 

miles from Boulder City and 30 miles east of Las Vegas, Nevada (figure 1). 

Formation of Lake Mead provided improvements to navigation, river regulation, 

flood control, and water storage for irrigation, beneficial consumptive uses, and 

releases for electric power generation. The dam and reservoir, part of the Boulder 

Canyon Project, are operated and maintained by the Reclamation’s LCR Office 

located near Hoover Dam in Boulder City, Nevada, figure 2. 
2001 Lake Mead Sedimentation Survey 

2

Figure 1 - Reclamation Dam locations in Nevada. 

Figure 2 - Hoover Dam and Lake Mead. 
3

Construction on Hoover Dam began in 1931. The dam began water storage on 

February 1, 1935 and was dedicated on September 30, 1935. The dam is a 

concrete gravity arched structure with the following dimensions: 

$ Hydraulic height1

 592.0 feet $ Structural height 726.4 feet 

$ Top width 45 feet $ Crest length 1,244 feet 

$ Top Dam, elev.2

 1,232.0 feet $ Top parapet wall, elev. 1,236.0 

Hoover Dam has two identical spillways located on the Arizona and Nevada 

canyon walls. Each spillway has a crest elevation of 1,205.4, a length of 400 feet, 

and has four 100-foot long steel drum gates that are 16-feet high with a crest 

elevation of 1,221.4 in their fully raised position. At reservoir water surface 

elevation 1,229.0, the combined capacity of the spillways is 63,000 cubic feet per 

second (cfs). With gates in fully lowered position (crest elevation 1,205.3, and 

reservoir at maximum water surface elevation 1,232.0), the combined spillway 

capacity is 400,000 cfs (figure 3). 

Figure 3 - Hoover Dam downstream releases. 

 1

 Definition of such terms as hydraulic height, structural height, etc. may be found in manuals such as 

Reclamation’s Design of Small Dams and Guide for Preparation of Standing Operating Procedures for 

Dams and Reservoirs, and ASCE’s Nomenclature for Hydraulics.

2

 All elevations in this report are shown in feet unless otherwise noted. Elevations based on dam’s 

construction datum from1935 survey. Add 0.55 feet to convert to National Geodetic Vertical Datum of 

1929 (NGVD29) (Lara and Sanders, 1970). 
2001 Lake Mead Sedimentation Survey 

4

On August 6 of 1941, Lake Mead’s water level was within one-foot of the 

spillway crest when the Arizona spillway gates were lowered allowing flows for 

the first time. When halted in early December 1941, an inspection of the spillway 

tunnel revealed a 38- by 112-foot eroded section of tunnel lining due to flow 

cavitation that required repairs. 

Completion of Glen Canyon Dam on the Colorado River, near the Arizona-Utah 

border, significantly altered the flood control operation of Hoover Dam and 

removed around two thirds of the previous sediment contributing drainage area 

above Lake Mead. The 710-foot high Glen Canyon Dam, completed in 1963, 

controls the Colorado River flows and traps nearly 100-percent of its upstream 

drainage sediments within Lake Powell. In 1983, heavy winter snows within the 

Colorado River basin created runoff 150 percent of normal, causing the first real 

use of the Glen Canyon and Hoover Dam spillways since 1941. This event 

caused significant cavitation damage to the spillway tunnels at both Hoover and 

Glen Canyon Dams that was similar to the 1941 damage. During spillway repairs 

design modifications were implemented to prevent future cavitation damage. 

Although the 1983 floods caused appreciable damage along the Colorado River, 

the damage would have been much greater without the network of basin dams. 

The outlet works are composed of four penstocks, each originating at one of the 

four intake towers upstream of the dam, and then tunneling behind the abutments 

before outleting for downstream releases. Each 395 foot tower has an outside 

base diameter of 82 feet at elevation 894. The intakes of the towers are at 

elevations 895.0 and 1,045.0 respectfully. The combined outlet works capacity is 

45,000 cfs at reservoir water surface elevation 1,232.0 (figures 4 and 5). 

Figure 4 - Hoover Dam intake towers and top of cofferdam. 
5

Figure 5 - Upstream face of Hoover Dam and four intake towers.

Cofferdams 

Upstream and downstream cofferdams were placed for protection during Hoover 

Dam construction (figure 6). The upper cofferdam construction began in 

September 1932 and was completed soon after the Arizona diversion tunnels. 

The upper cofferdam was located approximately 600 feet down river from the 

inlet portals of the diversion tunnels, stood 98 feet high, and reached about 30 feet 

above the top of the diversion tunnels. The upstream face was protected by a 6-

inch thick concrete paving laid over a 3 foot rock blanket. The downstream face 

was covered by a thick rockfill. The cofferdam design allowed the diversion 

tunnels to discharge 200,000 cfs with the water 13 feet below the crest. The 

lower cofferdam was 66 feet tall and built out of compressed earthfill material. 

There were concerns that during flooding, backwash from the outlet portals could 

damage the lower cofferdam, even with a thick rockfill covering the downstream 

face. To lessen the concern, a 54-foot rock barrier was built approximately 350 

feet downriver. The design drawing, 45-D-13857, labeled the top of the upper 

cofferdam at crest elevation 720. The 2001 survey measured the crest of this 

cofferdam (see report cover) at elevation 735 while previous surveys indicated the 

cofferdam was buried by sediment deposition. The Sedimentation Group’s 

analysis confirmed the measured 2001 top sediment elevation results with the 

general conclusion that sediment had accumulated upstream, downstream 

(between the dam and cofferdam) and on top of the cofferdam. It was the general 

conclusion that the previously deposited sediment in this area consolidated over 

time and the deposition raised the original top elevation of the cofferdam. 
2001 Lake Mead Sedimentation Survey 

6

Figure 6 - Hoover Dam cofferdams. 

Drainage Area 

The total sediment contributing drainage area above Hoover Dam from February 

1935 through March 1963 was 171,500 square miles, with 3,959 square miles 

considered naturally non-contributing (USGS, 2001). Since closure of Glen 

Canyon Dam and formation of Lake Powell in March 1963, the Colorado River 

and resulting sediment inflows have been regulated by Lake Powell. Lake Powell 

drainage area is 111,700 square miles, reducing the initial sediment contributing 

drainage area above Lake Mead by nearly two thirds to 59,800 square miles. The 

2001 Lake Mead study calculated the net sediment contributing area from 1935 

through 2001 as 105,550 square miles taking into account the total drainage area 

above Hoover Dam and the ratio of time since Glen Canyon Dam began 

controlling the Colorado River sediments upstream. Lake Mead’s width averages 

1.65 miles, varying from several hundred feet in the canyons to a maximum width 

of about 8 miles in the Boulder Basin area. Lake Mead’s total length is 152 miles, 

combining the lengths of the Colorado (115 miles) and Overton reaches. Figure 7 

provides an outline of the total Colorado River Basin which covers more than 

242,000 square miles within the United States and includes parts of Wyoming, 

Colorado, Utah, New Mexico, Nevada, Arizona, and California. The California 

portion of the basin only contributes downstream of Hoover Dam. 
7

Figure 7 - Colorado River drainage area (Dettinger, M.D. 1995). 

Summary and Conclusions 

This Reclamation report presents the 2001 Sedimentation Group’s results from 

the survey of Lake Mead. The primary objectives of the survey and analysis were 

to gather data needed to: 

$ develop reservoir topography 

$ compute area-capacity relationships 

$ estimate storage depletion by sediment deposition since dam closure 

$ estimate capacity change since 1963 closure of Glen Canyon Dam 

$ explain reservoir capacity increase since the 1963 survey. 

A Real-Time Kinematic (RTK) GPS control survey established a temporary 

horizontal and vertical control point near Lake Mead Marina that was used for the 

survey of the lower portion of the reservoir including Boulder Basin and Las 

Vegas Bay. The horizontal control was established in Universal Transverse 

Mercator (UTM) coordinate zone 11 in the North American Datum of 1983 

(NAD83). The RTK GPS control survey was conducted with the base set on a 
2001 Lake Mead Sedimentation Survey 

8

National Geodetic Survey (NGS) control point located downstream of the dam. 

Additional temporary control points were established, but due to time limitations, 

a decision was made to use a military issued GPS unit with horizontal accuracies 

of +4 meters from a single GPS receiver. This accuracy (+4 meters) met 

requirements for this survey as the study focused on measuring original bottom 

change from mostly flat-lying sediment deposition. 

The underwater survey was conducted over 22 days, from April 5 through May 15 

of 2001 between reservoir water surface elevations 1,189 and 1,194. The survey 

was conducted by a 2-person crew over the course of several days compared to 

previous surveys requiring large survey crews working for many months over a 

two year period. The bathymetric survey was conducted using sonic depth 

recording equipment interfaced with GPS capable of determining sounding 

locations within the reservoir. The system continuously recorded depth and 

horizontal coordinates as the survey boat navigated along pre-established grid 

lines covering Lake Mead. The positioning system provided information to allow 

the boat operator to maintain a course along these grid lines. Water surface 

elevations recorded by the reservoir gauge (tied to the Hoover Dam powerhouse 

datum) during the time of collection were used to convert the sonic depth 

measurements to reservoir bottom elevations. 

The above-water topography was developed from digital data of the original 

(prefill) topography scanned from USGS quad maps of the reservoir area. 

Additionally, a small portion of the upper reservoir area on the Colorado River 

was mapped using aerial collection techniques in 2001. The 2001 Lake Mead 

analysis utilized GIS tools for processing these large data sets. The 2001 Lake 

Mead topography was developed from a combination of the original and 2001 

data sets by plotting the 2001 data on top of the original data and deleting all 

original data overlaid by the 2001 data. Previously surveyed cross sections for a 

biological monitoring program on the Colorado River were used to complete the 

analysis of the reach of Lake Mead upstream of the 2001 aerial data by measuring 

change from the original river topography. The Sedimentation Group processed 

the 2001 topography data map by map for the entire reservoir by looking for 

change from the original measured map surface areas due to sediment deposition. 

When the 2001 data indicated no change due to sedimentation, the contour 

surface area was marked as no change, and the original surface area for the 10-

foot contour interval was used. This approach, similar to that used in previous 

studies, was the best means to compare the 2001 results with the original, 1948-49 

(1948) and 1963 results. 

As of September 2001, at reservoir elevation 1,229.0, the surface area was 

162,548 acres with a total capacity of 29,979,010 acre-feet. Since initial filling in 

February 1935, the 2001 study calculated 2,402,770 acre-feet of Lake Mead 

sediment accumulation with an average annual rate of 36,024 acre-feet for the 

66.7 year period compared to the 1963 computed average annual rate of 88,280 

acre-feet for the first 29.7 years of reservoir operation. 
9

The 2001 survey, at elevation 1,229.0, measured an increase in Lake Mead 

capacity of 219,150 acre-feet since the 1963 survey. The increase capacity was 

attributed to the significant compaction of the previous Lake Mead sediment 

deposition, the major decrease of sediment inflow since the 1963 closure of Glen 

Canyon Dam began trapping sediments in Lake Powell, and the ongoing 

compaction of the fine sediments that continue to deposit throughout the reservoir 

down to Hoover Dam. The study concluded the depth measurement methods for 

the different surveys were not a significant factor in the measured differences. 

The 2001 study did measure an increase in sediment deposition in the upper delta 

of the Colorado River from Greg Basin upstream, showing the face of the delta 

growing downstream towards the dam. 

The 2001 survey measured the greatest volume increase, due to compaction, in 

the Boulder and Virgin Basins. The greatest decrease in volume, due to sediment 

deposition, was measured in the upper reach of the reservoir downstream to the 

Pierce and Greg Basins. Compaction of sediment deposition occurs overtime 

throughout the reservoir, with the greatest compaction in the lower reservoir areas 

near the dam where the majority of the finer silt type sediments have deposited 

since initial filling. These finer sediments will continue to deposit throughout the 

reservoir down to the dam as confirmed by a 1998 program that collected 

sediment samples, in the lower reaches of the reservoir, consisting mainly of fine 

materials (Covay and Beck, 2001). 

The original published capacity of Lake Mead was 32,471,000 acre-feet at 

elevation 1,229.0. For the purpose of computing sediment deposition, the original 

capacity was recomputed, using the original surface areas and same computer 

program used to compute the 2001 values, resulting in a recomputed original 

capacity of 32,381,780 acre-feet. If Glen Canyon Dam and Lake Powell continue 

to trap Colorado River sediment at the same rate they have since 1963, and if 

current sediment inflow rates continue in the future, it will be several thousand 

years before Lake Mead fills with sediment. As noted previously, the first 30 

years of reservoir life occurred before closure of Glen Canyon Dam. Glen 

Canyon Dam closure in 1963 was followed by 37 years of Lake Powell capturing 

a large percentage of the Colorado River drainage sediments. The above reservoir 

life expectancy computations assumed the same sediment inflow and 100 percent 

Lake Mead and Lake Powell sediment trap efficiency. With the continual 

trapping of sediments in Lake Powell, the 2001 computed average annual rate of 

sediment inflow (36,023 acre-feet) since Hoover Dam closure will decrease over 

time until Lake Powell can no longer trap all sediments. Future measurements 

will better refine the average annual rate. Ongoing extensive data collection and 

studies in the Grand Canyon could also be used to better refine the current 

sediment inflow rate. Even though the projected Lake Mead life expectancy is 

thousand of years, sediment deposition will affect dam operations years prior. 
2001 Lake Mead Sedimentation Survey 

10

A rough estimate of Lake Mead’s present annual sediment accumulation, since 

Glen Canyon Dam closure, is less than 10,000 acre-feet. This estimate assumes 

the continual trapping of sediments in Lake Powell and ongoing consolidation of 

the finer sediments entering Lake Mead. One unknown is the amount of finer 

material entering and settling in the lower reaches of the reservoir. In the future, 

the impact of consolidation of Lake Mead sediments will be significantly reduced 

due to the major reduction of sediment inflow and compaction of the previous 

deposits that has already occurred. Since 1963, the 2001 survey data estimated 

7,200 acre-feet of annual sediment delta growth had occurred in the very upper 

delta portion of the reservoir on the Colorado River alone. More research and 

data would be necessary to better estimate sediment deposit in the other reaches, 

such as Overton and Las Vegas Wash. However, until the closure of Glen 

Canyon Dam these other sediment sources were insignificant compared to the 

total sediment inflow contributed from the Colorado River drainage basin. 

The 1986 Lake Powell survey measured an annual sediment inflow rate of 36,946 

acre-feet (Ferrari, 1988), significantly less than the 88,280 acre-foot average 

annual rate computed from the 1963 Lake Mead survey conducted prior to 

formation of Lake Powell. The 1986 Lake Powell rate may be less due to the 

other reservoirs developed in the upper basin in the 1960’s along with better land 

management practices. There have been some recent surveys and research 

conducted on Lake Powell that suggest the computed 1986 Lake Powell sediment 

inflow rate has continued (Clarke Hughes, 2005 and Pratson, 2007). Studies 

within the Grand Canyon indicate that the Colorado River is sediment deprived, 

and with no other major tributaries contributing sediment to Lake Mead, the 

significant drop in annual sediment rate will continue in the future. As this report 

demonstrates, future surveys can be conducted in less time using reconnaissance 

procedures for the collection and analysis, but still generate accurate results for 

monitoring change due to sediment deposition (Ferrari, 2006). 

The 2001 Lake Mead survey and analysis provided a unique opportunity in 

reservoir sediment monitoring. The previous survey in 1963 monitored the first 

30 years of reservoir operation with the upper drainage basin in a run of the river 

condition with minimal sediment control by upstream dams. After the 1963 

closure of Glen Canyon Dam, 63 percent of the sediment previously contributed 

by the drainage area was blocked and began depositing into Lake Powell. The 

2001 survey monitored the period of reservoir operation since this closure and 

provided an insight into the compaction of the previous sediment that had 

deposited in Lake Mead since closure of Hoover Dam. A bottom sampling 

program would need to be implemented to confirm and develop a better 

understanding of the compaction that has and will continue to occur within these 

deposited sediments. 

The 2001 survey did measure a buildup of the upstream sediment delta in the 

Colorado River reach of the reservoir. The deposition mainly consists of the 

heavier material, sand size and greater, that initially drops out due to the decrease 
11

transport capacity of the river as it enters the upper reservoir. During this 

deposition process the heavier material becomes sorted, where future compaction 

is minimal, and mostly remains in place until the reservoir level drops, allowing 

the river to erode the material and transport it further downstream into the 

reservoir. The 1998 sediment sampling program, though limited, showed that 

sediments continue to accumulate in the lower reaches of the reservoir towards 

the dam. These materials mainly consist of silt that is transported downstream by 

density currents where it eventually settles out and over the years will consolidate. 

Along with a bottom sampling program, future surveys will help in monitoring 

the consolidation of the bottom sediments. The surveys will be necessary to also 

calculate the current annual sediment inflow (estimated to be less than 10,000 

acre-feet per year in 2001). Future surveys will also assist in measuring the 

redistribution of sediment since the 2001 survey. Since the 2001 survey, the 

reservoir level has dropped over 80 feet, meaning a large portion of the previous 

sediment materials in the upper reservoir have been eroded downstream into the 

current operational reservoir range. 

Reservoir Operations 

Hoover Dam operates to provide flood control, power generation, and regulation 

of Colorado River flows downstream. The September 2001 capacity table shows 

29,979,010 acre-feet of total storage below flood control water surface elevation 

1,229.0. The 2001 survey measured a minimum lake bottom near elevation 689. 

The following values (from elevation 1229.0 and below) are from the September 

2001 capacity table: 

 $ 482,000 acre-feet surcharge, elevation 1,229.0 through 1,232.03

 $ 1,498,140 acre-feet flood control, elevation 1,219.6 through 1,229.0 

 $ 5,673,240 acre-feet joint use storage, elevation 1,083.0 through 1,219.6 

 $ 10,261,098 acre-feet inactive storage, elevation 895.0 through 1,083.0 

 $ 2,546,532 acre-feet dead storage, below elevation 895.0

Lake Mead’s computed annual inflow and reservoir stage records are listed by 

water year on table 4 for operation period 1935 through 2001. The water inflow 

values show the annual fluctuation with a computed average inflow of 10,900,000 

acre-feet per year between 1935 and 2001. The computed average inflow prior to 

closure of Glen Canyon Dam, 1935 through 1963, was 11,337,000 acre-feet. The 

computed average inflow for 1964-2001 was 10,549,000 acre-feet, indicating that 

Glen Canyon Dam had minimal impact to the annual water inflow compared to its 

significant impact on reduction of sediment inflows to Lake Mead. It must be 

pointed out that from 1983 through 1987 the Colorado River drainage basin 

 

3

 Capacity value, between elevation 1,229.0 and 1,232.0 (July 1977 Reservoir Capacity Allocation). The 

2001 study assumed no change in this elevation zone due to sediment deposition and shoreline erosion. 
2001 Lake Mead Sedimentation Survey 

12

runoff was significantly above average, with water years 1984 and 1985 the 

greatest listed runoffs since Hoover Dam closure. The initial filling of Lake 

Powell in 1963 and 1964 significantly reduced the flow of water into Lake Mead. 

Water years 1963 and 1964 inflows were less than fifty percent of the previous 

lowest Lake Mead inflow recorded in 1954. The maximum Lake Mead elevation 

was 1,225.8 during water year 1983 and, since initial filling, the minimum 

elevation was 1,083.2 during water year 1956. Since the 2001 survey, Lake Mead 

drainage has been in a prolonged drought with the reservoir level dropping to 

elevation 1,100 in September 2007. 

Purpose of Reservoir Surveys 

Reservoirs come in all shapes and sizes and are designed for purposes such as 

retention for flood control, debris/sediment storage, irrigation and municipal 

water supply, power production, recreation, navigation, conservation, and waterquality control. The reservoir size, shape, and operation affect the location and 

nature of the sediment deposition (figure 8). Reservoir sedimentation is an 

ongoing natural depositional process that can remain invisible for a significant 

portion of the life of a reservoir. However, lack of visual evidence does not 

reduce the potential impacts of sedimentation on functional operations of a 

reservoir (Lin, 1997). As sediment deposition depletes reservoir storage volume, 

periodic reallocation of available storage at various pool levels may be necessary 

to satisfy the operational requirements of water users. 

Figure 8 - Profile of reservoir delta formation. 

As rivers and streams enter a reservoir, the flow depth increases and the velocity 

decreases resulting in a loss in the sediment transport capacity of the inflow. The 

loss of sediment transport capacity and the damming effect of the reservoir may 

cause deposition of sediment in the stream channels above the reservoir water 

surface and in the upper reservoir area. The sediment deposition process in 
13

reservoirs generally follows the same basic pattern, with coarser sediments 

settling first in the upper reservoir area as the river inflow velocities decrease, 

forming a delta. As seen in figure 9, the early filling of Lake Mead in the 1940’s 

developed a typical delta formation. This included the heavier sediment, sands 

and gravel, settling in the upper reservoir area from Pierce Basin upstream, along 

with the finer sediments of silt and clays depositing throughout the original river 

channel alignment towards the dam (USGS, 1960). 

Figure 9 - Lake Meads’ longitudinal section through the Colorado delta, showing relation of 

bottomset beds to the topset and foreset beds. (USGS, 1960). 

The USGS 1960 report, Comprehensive Survey of Sedimentation in Lake Mead, 

describes the growth and structure of the delta beginning with Hoover Dam 

closure, on February 1, 1935, and continuing through December 1948. Initially 

the reservoir rose to elevation 700 and maintained that level for several months 

causing delta development and sand deposition from elevation 700 to the dam. 

With the 1935 spring runoff, the lake rose from elevation 700 to elevation 925 in 

July 1935 where, at this elevation, the Colorado River entered the reservoir in 

Pierce Basin about 75 river miles upstream of Hoover Dam. The reservoir 

elevation remained fairly constant until the following spring runoff. The delta 

continued to grow from 1936 through 1948 as the reservoir rose to a maximum 

elevation of 1,220.4 in July 1941, extending 110 miles upstream of the dam. Core 

samples found the surfaces of the topset bed to be hard compact sand and the 

bottomset bed to be extremely soft mud with solid particles composed of silt and 

clay. It is these areas of the reservoir, the soft mud and fine sediments consisting 

of silt and clay, that have consolidated the greatest overtime. 

The process through which inflowing fine sediment is transported downstream 

into the lower portions of Lake Mead can be explained by density currents. Other 

conditions, such as reservoir drawdown, can cause higher inflow velocities to 
2001 Lake Mead Sedimentation Survey 

14

erode the upper reservoir sediment delta and transport material further 

downstream. However, sediments eroded from the delta are primarily composed 

of the coarser material that deposits soon after entering the new reservoir pool. 

The density current influence occurs where one fluid flows over or under another 

due to differences in their density. In reservoirs, the density difference can cause 

warm water to flow as a surface current across the top of the colder denser water. 

Alternatively, the cooler inflowing turbid water may plunge below the warmer 

reservoir surface water (figure 10) and travel across the top of the thermocline 

downstream towards the dam (Morris and Fan, 1997). 

Figure 10 – Colder Colorado River inflow interface, upper Lake Powell. 

Initial evidence of density currents within Lake Mead emerge within months after 

Hoover Dam closure. Evidence of the density currents flowing through the entire 

reservoir length was documented during the first 15 months of operation (Grover 

and Howard, 1938). These findings led to additional investigation from 1936 

through 1949 summarized in the 1948 Lake Mead survey report (USGS, 1960). 

The studies found that spikes in suspended sediment measurements in the 

Colorado River in the Grand Canyon were followed days later by corresponding 

spikes in suspended sediment measurements in the Colorado River below Hoover 

Dam. When a measurement spike decreased at the Grand Canyon, the 

downstream suspend measurements below the dam decreased days later. These 

studies were performed with the reservoir length at nearly 90 miles and with 

downstream flow releases through the bypass tunnels located near the bottom of 

the dam at around elevation 700. The studies concluded that the colder turbid 

water flowed through the reservoir along the bottom and remained essentially 

unmixed. In May 1936 the bypass tunnel was permanently plugged and since 
15

then, the majority of releases have been through the intake towers with a 

minimum elevation of 895.0. The tunnel closure prevented the downstream 

releases of the highly turbid water, effectively trapping it in the lower reservoir 

zone. Density currents were continually monitored by measuring the top of the 

sediment surfaces at the intake towers, figure 11. The results indicated that 

during periods of high suspended sediments in the Colorado River, the top 

elevation of the sediment deposition at the dam increased. It appears that the 

turbid flows impacted the barrier formed by the dam and exploded into a plume of 

suspended material, temporarily causing higher measured bottom elevations. 

Eventually the initial plume settled to the reservoir bottom resulting in lower 

measurements again. Over time these presumably fine sediments consolidated in 

place forming a more solid reservoir bottom where additional turbid flows of 

suspended material subsequently deposit. 

Figure 11 - Periods of reported density currents and elevation of sediment surface at Hoover 

Dam, 1935 through 1950 (USGS, 1960). 

Reservoir sediment deposition continues from upstream to downstream with the 

sediment gradation becoming finer as the deposition progresses in the 

downstream direction throughout the length of the reservoir to the dam. Some of 

the inflowing fine sediments (silts and clays) may stay in suspension and 

discharge through the dam outlets and spillways, as seen from the early Lake 

Mead releases through the bypass tunnels. However with the minimum intake 

elevation raised 195 feet from the dam base to the bottom of the towers, the 

suspended sediment releases have been greatly reduced with nearly 100 percent 

trapped behind Hoover Dam. Over the years as sediment deposits nearer the dam 

inlets, some will eventually be discharged downstream, even though the majority 

of the sediment currently settles on the reservoir bottom and consolidates in place. 
2001 Lake Mead Sedimentation Survey 

16

In the United States, reservoir sedimentation seldom receives attention until the 

reservoir capacity has been significantly reduced or the reservoir operation and 

surrounding area is affected. The delta formation can cause local problems before 

sediment deposition significantly reduces reservoir capacity or causes operational 

problems at the dam. Some local problems that have been attributed to sediment 

deltas are increased elevation of the flood stage and groundwater table, silting of 

pumping and intake structures, and blockage of navigation passages. Once at the 

dam, the released sediments may have downstream impacts on river fisheries and 

municipal water systems. Even though the 2001 Lake Mead study measured an 

increase in reservoir capacity, the delta in the upper end of the reservoir continues 

to grow and cause access issues for users of the upper reservoir and lower reaches 

of the Colorado River in the Grand Canyon. 

The primary objective of a reservoir survey is to measure the current area and 

capacity. The main cause of storage capacity change is sediment deposition or 

erosion. Typical results from a reservoir survey and analysis include the 

measured sediment deposition since dam closure and previous surveys, the 

sediment yield from the contributing drainage, and the future storage-depletion 

trends. Survey results can also include location of deposited sediment (lateral and 

longitudinal distribution), sediment density, reservoir trap efficiency, and 

evaluation of project operation. 

The Sedimentation Group typically computes reservoir sediment accumulation by 

comparing the measured original capacity, prior to inundation, to the updated 

measured capacity. This method calculates a long-term sediment deposition value 

used for future sediment projections. Making comparisons to the original survey, 

rather than comparing to the previous survey only, prevents errors that might exist 

in previous resurvey results from being included in the analysis. During the 

analysis all previous survey results are compared to study trends. The 

calculations typically rely on accurate original reservoir topography available for 

many of Reclamation’s reservoirs, but are evaluated on a case-by-case basis. 

Modifications to the analysis and study objectives are made for cases where 

accurate original reservoir topography is not available. Examples of studies 

where accurate original reservoir topography was unavailable include the 1995 

Theodore Roosevelt (Roosevelt) Reservoir survey (Lyons-Lest, 1996) and the 

2002 Deadwood Reservoir survey (Ferrari, 2003). 

The Roosevelt and Deadwood Reservoir resurveys measured better detail than the 

original survey data. The 1995 Roosevelt survey was the eighth survey since dam 

closure in 1909, but the first survey to use aerial photography providing more 

detail of the upper reservoir elevations than the original 1909 survey (which used 

land-surveying techniques) and other previous resurveys. Comparing the detailed 

1995 survey with previous mapping information was not an acceptable method 

for computing sediment accumulation due to the major accuracy differences 

between the surveys. However, the previous resurveys of Roosevelt Reservoir 
17

were valid for computing sediment inflow since they utilized a range line 

collection method that monitored the same range line location over the years. The 

changes at these locations were compared to the original topography for 

estimating the sediment deposition. The detailed 1995 Roosevelt Reservoir 

survey should now be used as the basis for future comparisons. The same was 

true of the 2002 Deadwood Reservoir resurvey where the detailed aerial and 

multibeam data from the 2002 survey could not be compared to the much less 

detailed original data for computing sediment accumulation. 

The 2001 study of Lake Mead collected very detailed survey data, but only about 

30 percent of the total reservoir surface area was covered (LCR, 2003). A 

combination of aerial and underwater collection would be necessary to obtain 

total reservoir topography providing the most accurate area and capacity results. 

Improved technologies may allow full reservoir surveys in a more effective 

manner in the future, but for the 2001 survey, these technologies were not yet 

available. The 2001 Lake Mead study analysis used the 2001 detailed data to 

adjust the original measured surface by map boundary and to compute updated 

reservoir capacity and resulting loss due to sediment deposition. The detailed 

2001 survey collection focused on known areas of sediment accumulation. The 

2001 analysis assumed the original computed surface areas were correct, using 

them as the base for measuring change. There were only minor issues in dealing 

with accuracy differences between the data sets. 

Additional objectives of the Sedimentation Group’s reservoir survey studies are to 

develop reservoir topography, estimate reservoir economic life, and resolve 

storage capacity conflicts. The resulting study information is beneficial for 

describing existing conditions for a specific reservoir, monitoring upstream land 

management practices, evaluating current operation of a reservoir, and planning 

future reservoirs. The results from the study can provide insight for such 

operational objectives as sluicing sediment deposits to increase reservoir volume 

and possibly enhancing the downstream river environment, establishing bench 

marks for forecasting future reservoir depletion rates, revising intake or outlet 

design, assessing water quality control methods, and designing recreation 

facilities, structures, and operational schedules. 

Reservoir sediment accumulation and distribution can be approximated 

theoretically. However, an accurate reservoir survey is the best means for 

monitoring current reservoir sedimentation and for projecting future sediment 

inflow and deposition. The most accurate data requires measurement of the 

complete reservoir area, or as much of the sediment delta as possible. As seen in 

figure 8, the majority of the delta usually forms in the upper reaches of the 

reservoir with inflowing sediments eventually depositing throughout the reservoir. 

Full coverage requires both above and below water measurements that 

significantly increase field collection time and cost. 
2001 Lake Mead Sedimentation Survey 

18

The reconnaissance method presented for the 2001 Lake Mead collection focused 

the underwater collection on the known sediment deposition zones of the 

reservoir, significantly reducing the effort and associated costs. The 2001 

collected data was used along with the best available alternate data sources to 

complete the sediment analysis. The main goal was to obtain up-to-date valid 

information within allowed time and budget that otherwise would not be collected 

(Ferrari, 2006). This report summarizes the techniques applied and the final 

results of the 2001 Lake Mead survey conducted by Reclamation’s Sedimentation 

Group. 

Hydrographic Survey Equipment and 

Method 

Hydrographic survey equipment has transformed dramatically throughout history, 

with the greatest changes occurring over the last few decades (Ferrari and Collins, 

2006). The latest major change in horizontal positioning is the use of GPS 

technology that is more accurate and less costly to operate than past survey 

equipment. GPS has been rapidly adapted to hydrographic collection systems. 

The most recent significant development in depth sounding is the multibeam 

system that allows massive amounts of data to be collected. The multibeam 

system provides the option of complete coverage of the underwater areas, thus, 

removing the unknowns of previously unmapped underwater areas. 

The hydrographic survey equipment was mounted in the cabin of a 24-foot tri-hull 

aluminum vessel equipped with twin in-board motors, figure 12. The 

hydrographic system included a GPS receiver with built-in radio, depth sounder, 

helmsman display for navigation, computer, and hydrographic system software 

for collecting the underwater data. An on-board generator supplied power to all 

the equipment. When differential GPS was used, the shore equipment included a 

second GPS receiver (base) with an external radio. The base GPS receiver and 

antenna were mounted on a survey tripod over a known datum point and a 12-volt 

battery provided the power. 

The Sedimentation and River Hydraulics Group uses RTK GPS with the major 

benefit being precise heights measured in real time to monitor water surface 

elevation changes. The basic output from a RTK receiver are precise 3D 

coordinates in latitude, longitude, and height with accuracies on the order of 2 

centimeters horizontally and 3 centimeters vertically. The RTK GPS system 

employs two receivers that track the same satellites simultaneously, just like with 

differential GPS. The output was on the GPS datum of WGS-84 which the 
19

Figure 12 - Survey vessel with mounted instrumentation on Jackson Lake, Wyoming. 

hydrographic collection software converted into UTM zone 12 coordinates in 

NAD83. For the Lake Mead study the regional office requested the collection be 

conducted in UTM and depths in meters to conform to ongoing USGS studies 

(Twichell, 1999). For the Sedimentation Group’s analysis, the resulting data was 

converted to English units for comparing with the original and previously 

collected data. The survey also used a military issue GPS system for collecting 

position information with a horizontal accuracy of + 4 meters. 

The 2001 Lake Mead survey was the first by the Sedimentation Group utilizing 

the integrated multibeam hydrographic survey system. The system consists of a 

single transducer mounted on the center bow or forward portion of the boat. 

From the single transducer a fan array of narrow beams generates a detailed cross 

section of bottom geometry as the survey vessel passed over the areas to be 

mapped. The system generates 80 separate 1.5 degree slant beams resulting in a 

120-degree swath from the transducer. With a fan of 120 degrees, the bottom 

sweep width is around 100 feet in 30 feet of depth and around 1,400 feet in 400 

feet of depth. The 200 kHz high-resolution multibeam echosounder system 

measured the relative water depth across the wide swath perpendicular to the 

vessel’s track. The multibeam system illuminates a swath of the sea floor that is 

about 3.5 times as wide as the water depth below the transducer (figure 13). 
2001 Lake Mead Sedimentation Survey 

20

Figure 13 - Multibeam collection system. 

The multibeam system is composed of several instruments that are all in constant 

communication with a central on-board notebook computer. The components 

included the GPS for positioning; a motion reference unit to measure the heave, 

pitch, and roll of the survey vessel; a gyro to measure yaw or vessel attitude; and 

a velocity meter to measure the speed of sound through the reservoir water 

column. With the proper calibration, the data processing software utilizes all the 

incoming information to provide an accurate and detailed x, y, z data set of the 

lake bottom covered by the survey vessel. 

The Lake Mead bathymetric survey collection was conducted over 22 days from 

April 5 through May 15 of 2001 between water surface elevation 1,189 and 1,194 

(project datum). The survey was run using GPS and multibeam system 

instrumentation as described above. The survey system software continuously 

recorded reservoir depths and horizontal coordinates as the survey vessel moved 

across closely-spaced grid lines covering the reservoir area. Most transects (grid 

lines) were run along the original river alignment of the reservoir where the 

multibeam swaths overlapped each other. The overlapping swaths assured 

complete coverage in the deeper portions of the reservoir and were used during 

processing to confirm that motion detector data was applied correctly. In the 

shallower depths, around thirty feet and less, the swaths did not overlap. The 

multibeam system could have provided full bottom coverage in this depth zone, 

but time, budget, and access did not allow this. Due to the cost and sensitivity of 

the multibeam transducer, the collection crew usually limits data collection to 

depths of 10 feet and greater. The loss of these additional data points did not 

significantly impact the area computations since it usually occurred in shallower 
21

areas where the bottom topography was generally flatter due to the sediment 

deposition. 

The 2001 bathymetry included some single beam data in the shallow water areas 

of the reservoir, primarily in the Overton Arm, that was used for mapping these 

areas. A longitudinal profile of single beam depths was collected from the upper 

Overton Arm downstream to the Colorado River confluence. Comparisons 

between the single beam and multibeam data found that the depths for the two 

systems generally agreed within a foot, providing further validation of the 

multibeam collected depths. 

During the 2001 survey of Lake Mead’s Grand Bay area, a ridge was measured as 

the survey vessel maneuvered from the main channel of the Colorado River into 

Grand Bay. The collection crew also observed a significant difference in the 

clarity of the water in Grand Bay versus the main stem of the reservoir. As the 

vessel mapped upstream into Grand Bay, the depths increased slightly. It appears 

the sediment deposition along the original river channel created levee or berm 

type features along the channel banks as the lake level lowered. This barrier at 

the confluence of Grand Bay blocks the water in the bay preventing the Grand 

Bay sediments from entering the Colorado River portion of the reservoir and 

preventing the Colorado River sediments from depositing in Grand Bay during 

periods of lower reservoir elevations. The 2001 map showed two independent 

water bodies within the Lake Mead boundary. Since the 2001 survey, Lake Mead 

has significantly dropped in elevation exposing the upper reservoir area, figure 

14. As seen from the image, the previously formed dike at Grand Bay became a 

barrier forming an independent water body within Grand Bay. If the lake were to 

continue to drop, this condition would also occur at some of the other tributaries 

such as the Overton Arm and Las Vegas Bay. These sediment formed barriers 

will likely remain until a high tributary flow over tops and scours the formation. 

The single beam system was calibrated by bar check and the multibeam system by 

velocity profiler, providing independent checks of the two depth systems. Both 

systems were also checked by dropping a marked cable with weighted pod over 

the side of the boat in calm water conditions. Even in these ideal conditions, the 

length of the marked cable limited this check to less than 200 feet of water. The 

collection crew attempted to collect single beam data near the dam, but the 

onboard single beam instrument did not allow collection greater than 400 feet. As 

explained in the analysis section, additional checks and comparisons were made 

with other independent data sets to assure quality depth data was collected by 

both the single beam and multibeam collection systems. 
2001 Lake Mead Sedimentation Survey 

22

Figure 14 - Upper end of Lake Mead after significant drop of reservoir content since 2001 

survey. Exposed Pierce Basin sediment delta, lower right. Grand Bay water body formed 

by sediment dike, top right corner (NASA, Visible Earth, visibleearth.nasa.gov).

Methodology 

The Sedimentation Group continuously upgrades their technical procedures to 

reflect the latest data collection technology and analysis procedures. Prior to 

computerized data collection and analysis systems, the range-line method was 

viewed as the only practical method for collection due to its relatively low field 

and analysis costs. The range-line method was used most often on medium to 

large reservoirs such as Lake Mead (Lara and Sanders, 1970) and Lake Powell 

(Ferrari, 1988). The collection and analysis consists of determining sediment 

depths along predetermined range-lines. Analysis required detailed and accurate 

original reservoir topography. The range-line method is still a valid means of 

conducting survey studies for certain reservoir conditions. For the 1986 Lake 

Powell Survey, the range-line method was used due to deep, greater than five 

hundred feet at the dam, vertical wall conditions and good original topographic 

maps. It now is possible to completely map reservoirs such as Lake Mead and 

Lake Powell using GPS, multibeam system, and aerial collection, but the rangeline method of analysis can still be considered for collection and analysis. A 

Grand Bay 

Pierce Basin
23

multibeam survey can cover in days what took months in 1986 on Lake Powell 

and resulted in range–line-type data at a much higher density (Ferrari, 2006). 

The contour method has become the preferred method for data collection and 

analysis with the development of electronic collection and analysis systems. It 

requires large amounts of collected data to obtain accurate results, something 

present systems can handle. The contour method results in more accurate 

reservoir topography and computed volumes than the range-line method. The 

most accurate contour method is the survey of both the above and below water 

portions of the reservoir area. The ideal contour map is developed by 

photogrammetry (aerial) when the reservoir is empty exposing all areas to be 

measured, but this condition seldom occurs, making a combination of aerial and 

bathymetric surveys necessary. To reduce the time and cost associated with 

underwater data collection, the aerial data should be collected when the reservoir 

is as low as possible and the bathymetric survey conducted when the reservoir is 

as full as possible, providing maximum overlap of the two data sets. Surveying 

the underwater portion after the aerial survey with a large overlap reduces the 

time and cost as the survey boat does not have to maneuver in shallow water 

portions mapped by the aerial survey. 

GPS Technology 

GPS collection techniques can vary depending on cost, need, and availability. 

Absolute positioning normally involves a single GPS receiver and at one time was 

not accurate enough for use in hydrographic positioning. Previously, a large error 

source in GPS collection was false signal projection implemented by the US 

Government to discourage use of the satellite system as a guidance tool by hostile 

forces. When active, the errors were up to +100 meters horizontally. This 

practice was eliminated by Presidentional order in May of 2000, resulting in 

absolute positioning errors of around +8 meters which still may not satisfy all 

hydrographic surveying requirements. 

A method of collection to resolve or cancel the inherent errors of GPS is called 

differential GPS (DGPS). Differential surveying is the positioning of one point in 

reference to another with the basic principal being that errors calculated by GPS 

receiver at a known point or datum would have common errors with other GPS 

receivers in the general area. DGPS determines the position of one receiver in 

reference to another and is a method of increasing position accuracies by 

eliminating or minimizing the uncertainties. Differential positioning is not 

concerned with the absolute position of each unit, but with the relative difference 

between the positions of the two units that simultaneously observe the same 

satellites. 

Real-time DGPS, the current standard for hydrographic positioning, is where a 

master receiver is stationed over a known datum as it computes, formats, and 

transmits correction information through a data link to the mobile GPS receiver 
2001 Lake Mead Sedimentation Survey 

24

on the survey vessel. There are community base stations maintained by United 

States Federal, state and local government offices and commercial services that 

transmit GPS correction information. The main weakness in real-time collection 

systems is the communication link between the master and mobile GPS receivers. 

Surveying on open water removes most obstacles, but communication problems 

can occur with all systems when surveying in areas with obstructions such as 

mountains, cliffs, vegetation, and structures along the shoreline. When these 

situations occur, the flexibility of the hydrographic survey crew being able to 

move the master receiver to new locations makes it more viable, but at times, 

more costly. 

RTK GPS in hydrographic surveying provides the highest precision of GPS 

positioning. The major benefit of RTK versus DGPS is that precise heights can 

be measured in real-time. This is a major benefit for surveys in tidal and river 

conditions, but not as necessary on reservoirs with more stable daily water 

surfaces. The basic output from an RTK receiver are precise three-dimensional 

coordinates with accuracies on order of two centimeters horizontally and three 

centimeters vertically. RTK GPS employs at least two receivers that track the 

same satellites simultaneously, just like with DGPS. To obtain high accuracies, 

the base station must be near the survey vessel. 

A positioning technique available to the military is called precise positioning 

service (PPS) that obtains +4 meter accuracy from a single GPS receiver. With 

Department of Defense (DOD) authorization, a nonmilitary Government agency 

can utilize PPS. The Sedimentation Group used PPS for navigation in the upper 

area of Lake Mead above Boulder Basin. The reconnaissance techniques used on 

Lake Mead were not adversely affected by the GPS methods since the analysis 

was only concerned with bottom change due to the flat lying sediments. 

The Sedimentation Group’s goal for all surveys is to collect the most accurate 

data possible within a reasonable budget. The results of the Lake Powell and 

Lake Mead collections appear to show that any of the GPS methods will 

adequately map the bottom sediments in the original river channel alignment. As 

long as the study is mainly measuring the change within the original digital 

contours due to the flat lying sediments, absolute GPS position solutions should 

be adequate. If full bottom mapping or more accurate location of features is 

needed, then much higher GPS position solutions are necessary. It is 

recommended that the differential positioning method be used via commercial or 

Governmental broadcast, but there could still be areas these signals cannot be 

obtained due to signal blockage by the surrounding topography or other 

obstructions. 
25

Depth Measurements 

Over the last 60 years, the majority of all hydrographic surveys have been 

conducted using some form of acoustic depth sounder that provides a digital 

record (the 1940’s and 1960’s Lake Mead surveys used this type of system). 

These echo sounders have the capability of recording continuous profiles of the 

reservoir bottom, providing an analog bottom profile chart, and digital computer 

records. The computer system software matches these depths with other digital 

information such as horizontal positioning and heave components. The basic 

components of a depth sounding system are the data recorder, transmitting and 

receiving transducer, and power supply. With careful calibration and correct 

collection techniques, a high degree of bottom profile accuracy can be obtained 

and recorded. 

Calibrations of the echo sounder are critical in assuring high-quality depth 

measurements by the bathymetric survey system. The largest and most critical 

correction results from the variability of the sound velocity in water due to 

temperature changes, but other factors such as water density, salinity, turbidity, 

and depth also affect the sound velocity. Most reservoirs exhibit large variations 

in temperature with depth, meaning the velocity of the sound wave will not be 

constant over the distance from the depth sounder’s transducer to the bottom 

depth and back. The effect of the variation can be significant, a temperature 

change of 10 o

F can change the velocity 70 feet per second, changing the depth 

measurement 0.8 feet per fifty feet of depth. For reservoirs such as Lake Mead 

and Lake Powell, the summer water temperatures near the surface can be in the 

high 70-degree range while temperatures at the bottom depths are in the 40-degree 

range causing a significant change in the sound velocity through the vertical 

zones. 

For most single beam, shallow water, echo sounding work, an average velocity of 

sound can be used. Bar-check calibration determines the actual depth at the study 

area, and the sound velocity on the echo sounder is adjusted to measure the 

correct depth. If the study is conducted in areas with known large variations in 

velocity by depth or location, the sounder should be set to measure the average or 

deeper depths that will be encountered during that survey over the area being 

covered. For these types of conditions, frequent calibrations are needed. The 

sound velocity can be determined by a bar check calibration or measured directly 

using a velocity probe. Many velocity probes can measure the sound velocity at 

every foot of depth. An average value can be computed from these 

measurements, or with hydrographic software, the depth incremented velocity 

measurements can be recorded, stored, and used during postprocessing to adjust 

sounder measurements to actual depths. The method of using a velocity probe for 

measuring depth-related sound velocities is more critical for multibeam systems 

when correcting the field readings, mainly for the outer beam depth adjustments. 
2001 Lake Mead Sedimentation Survey 

26

For the 2001 Lake Mead survey, a velocity meter with a 100-meter-long cable 

was used to obtain readings at 1 meter increments. Besides the collection of 

velocity profiles on a consist basis, the multibeam measurements were further 

verified by more conventional methods. During calm reservoir conditions, an end 

weighted calibrated cable was lowered from the survey vessel in around 180 feet 

of depth. The results compared well with the corrected multibeam depths. The 

multibeam depths also compared well with the deeper single beam depths at the 

confluence of the Overton and Colorado River. The single beam sounder was 

calibrated using a standard bar check and was evaluated independent of the 

multibeam soundings, further confirming the resulting elevations. 

The Lake Mead survey was the first use of a multibeam system by the 

Sedimentation Group. Multibeam was used to measure the sediment deposition 

from the dam to the upper shallow water areas of the reservoir. For navigationtype surveys, it is recommended there be a 50 percent overlap of the survey 

sweeps for quality control. For reservoir sediment surveys, the overlap can be 

reduced in the deeper portions of the reservoir, but the overlap should be enough 

to assure the outer beams of the two sweeps are collecting high quality data. The 

2001 Lake Mead final product included filtered x, y, z data points resulting in 

cross sections every 2 to 5 meters for the underwater reservoir areas covered by 

the survey vessel. 

Additional Studies and Information

Original Topography of Lake Mead 

The early topography of Lake Mead was based on the John Wesley Powell 

surveys of 1869 (Brown, 1941). In 1922 and 1923, the USGS, in cooperation 

with Reclamation, conducted profile surveys of the Colorado River from the 

mouth of the Green River to Needles, California, under leadership of Colonel C. 

H. Birdseye. Using plane table survey methods, topographic maps were made 

with 50-foot contours at a scale of 2 inches to 1 mile from Black Canyon 

upstream to the Lower Granite Gorge. The contours were developed to elevation 

1,250 (Brown, 1941). 

In 1930, additional topographic maps were developed around the proposed dam 

site at a scale of 1 inch equals 400 feet with 5-foot contour intervals. These maps 

and mosaics were made by Brock and Weymouth of Philadelphia and were found 

to conform to the standards maintained for the 1935 survey of the entire Lake 

Mead area (Brown, 1941). 

With Hoover Dam closure on February 1 of 1935, it became critical for aerial 

photographic methods to be considered for the reservoir mapping to be extended 

beyond the 1930 aerial coverage. The contract was awarded to Fairchild Aerial 
27

Surveys on February 23 of 1935, and five hours later, photographs were taken of 

the critical areas before they were inundated by the filling reservoir. The basic 

aerial photography of the entire reservoir area was completed on February 27 of 

1935. To complete the map processing required extensive control and other 

ground surveys that are summarized in the report “Mapping Lake Mead “(Brown, 

1941). The maps were developed at a scale of 1 inch equals 1,000 feet with 10-

foot contours on 45 map sheets. There were 5-foot contours developed near the 

dam from the 1930’s survey. 

The measurements of the contour areas were completed by the Division of 

Cartography of the Soil Conservation Service using an alternative method 

confirmed by standard planimetered measurements. It was estimated that the 

planimetered measurements, acceptable standard at that time, would have 

involved 436 man weeks at an estimated 1930’s cost of $18,749. An alternative 

method was proposed for measuring the irregular parcels called the weight 

apportioning method that consists of actually cutting out each individual area and 

weighing each on a highly sensitive analytical balance and computing the 

proportion of the weight of each area to the whole area. The coordinates of the 

survey control were used to compute the total acreage. The work on the map 

sheets began in April 1939 and was completed in March 1940 at a cost of $2,500. 

To complete the process, each 5-minute quadrangle was photostated without 

change in scale and exceptional care was taken to prevent expansion and 

contraction of the paper. Numerous tests were made of the uniformity in weight 

of the different samples and when necessary, small corrective factors were 

applied. As a check to the weight-apportioning method, each 100-foot contour 

was planimetered and in every case the resulting area agreed within one percent. 

The surface area results, with some adjustment from the original calculations, are 

listed in the 1963 report (Lara and Sanders, 1970). In 1935 the Soil Conservation 

Service, in cooperation with Reclamation, computed the original capacity of Lake 

Mead from these 10-foot incremented surface areas (SCS, 1940). Table 1 is a 

recreation of table 3-3 of the 1963 report that lists the original surface areas, by 

indicated map, measured at 10-foot elevation increments. 

 
2001 Lake Mead Sedimentation Survey 

28
29

Sheet No

660 670 680 690 700 710 720 730 740 750 760 770 780 

1,2,3

4 73.82 136.86 205.08 241.55 277.71 313.89 358.26 400.65 464.69 511.99 552.07 5 128.00 190.16 423.44 460.82 519.06 582.59 652.13 715.86 769.55 813.95 858.84 913.62 

6,7 365.79 663.69 1,106.57 1,388.97 1,643.85 1,813.78 1,990.57 2,166.27 2,426.19 2,662.51 2,828.78 2

8 227.62 734.97 913.19 1,178.06 1,326.15 1,400.32 1,466.88 1,525.43 1,578.10 1,621.83 1,677.21 1,734.17 1,790.08 9 3.98 23.47 134.02 386.26 457.04 520.57 582.76 640.55 678.27 717.17 744.17 768.88 

10

11,12 36.54 123.61 275.83 382.95 610.64 874.94 993.54 1,099.84 1,254.24 

1415161718 

19 288.62 1,209.54 1,448.00 1,874.06 2,245.40 2

20,21

2223242526 100.12 

27 2.59 345.01 542.03 707.01 839.14 283031323334 118.93 174.88 198.54 238.42 35 12.55 122.87 392.85 36 3738 1.35 13.72 3940414243444546474849505152

Total 227.62 866.95 1,566.43 2,536.07 3,521.42 4,130.55 4,767.43 5,270.94 6,185.19 8,184.99 9,270.21 10,515.35 11,937.32 13

10 - Foot Contour Areas in Acres

Elevation (feet)

Table 1-1935 Lake Mead Surface Areas (1 of 4).
2001 Lake Mead Sedimentation Survey

30

Sheet No Elevation (feet) 

820 830 840 850 860 870 880 890 900 910 920 930 9

1,2,3

4 729.08 781.26 829.21 881.54 940.89 1,018.71 1,112.06 1,208.88 1,321.97 1,448.63 1,586.39 1,727.66 1,865.5 1,422.75 1,577.07 1,719.89 1,862.11 2,006.37 2,197.14 2,318.83 2,503.16 2,710.80 2,940.59 3,099.03 3,235.06 3,423.

6,7 3,407.43 3,541.45 3,698.77 3,858.52 4,034.51 4,213.40 4,433.06 4,608.68 4,727.52 4,918.80 5,094.28 5,276.14 5,485.

8 2,031.74 2,089.03 2,147.32 2,211.16 2,279.50 2,341.28 2,403.01 2,455.15 2,512.82 2,587.73 2,643.16 2,690.08 2,757.9 918.26 956.16 993.69 1,045.35 1,098.46 1,151.75 1,206.41 1,261.06 1,318.28 1,385.41 1,455.04 1,520.45 1,578.

10

11,12 1,728.29 1,809.59 1,873.10 1,946.31 2,021.43 2,088.52 2,163.52 2,253.84 2,338.08 2,456.98 2,533.51 2,620.56 2,689.

1415161718 499.46 635.73 798.29 901.72 998.58 1,066.86 1,149.05 1,190.72 1,225.00 1,313.95 1,360.66 1,441.79 1,513.19 4,034.76 4,380.65 4,637.82 5,025.43 5,301.62 5,449.20 5,758.26 5,983.84 6,203.50 6,445.21 6,688.94 6,901.47 7,134.

20,21

22232425 2.32 72.52 149.19 223.52 358.91 503.04 720.26 1,008.90 1,076.59 1,172.77 1,275.23 1,429.11 1,622.95 1,771.95 1,912.45 2,057.28 2,228.68 2,381.62 2,528.41 2,672.27 1,214.39 1,373.38 1,516.04 1,804.83 1,998.98 2,159.17 2,327.55 2,517.89 2,695.22 2,938.69 3,319.14 3,727.00 3,998.283031323334 336.09 354.05 371.30 396.61 418.52 453.20 478.99 510.19 544.53 596.56 643.33 700.13 746.35 1,103.07 1,226.74 1,351.58 1,481.77 1,607.14 1,734.94 1,873.57 2,036.65 2,206.25 2,372.14 2,513.49 2,669.70 2,828.36 303.01 327.31 350.83 385.28 407.63 434.12 454.84 498.56 509.53 529.81 578.21 605.73 634.37 6.23 76.07 227.26 409.61 654.77 851.32 980.47 1,104.45 1,244.67 1,366.97 1,470.43 1,584.50 1,689.38 303.03 570.55 783.64 1,199.20 1,350.00 1,445.00 1,527.15 1,632.56 1,716.95 1,832.32 1,917.41 2,008.18 2,115.3940 1.94 26.87 109.48 202.70 295.91 419.78 543.63 595.62 647.58 697.13 746.41 16.89 60.72 89.90 102.14 110.32 118.64 124.23 132.94 138.42 9.43 76.34 119.42 148.00 169.00 185.40 199.43 3.42 41.96 136.07 386.72 590.91 682.71 771.44 2.12 53.30 128.05 217.20 278.4546 0.23 0.474849505152

Total 19,046.49 20,775.63 22,473.45 24,711.54 26,673.88 28,490.98 30,359.70 32,390.82 34,393.15 36,888.27 39,303.32 41,655.51 43,989.

10-Foot contour Areas in Acres

Table 1 - 1935 Lake Mead Surface Areas (2 of 4). 
31

Sheet No

970 980 990 1000 1010 1020 1030 1040 1050 1060 1070 1080 

1,2,3 14.86 30.26 50.42 78.07 111.64 150.54 

4 2,303.37 2,479.31 2,671.47 2,876.36 3,078.50 3,299.77 3,519.95 3,739.29 3,978.76 4,221.40 4,434.55 4,658.49 5 4,014.64 4,168.55 4,343.44 4,484.45 4,714.97 4,876.11 5,014.37 5,148.99 5,290.08 5,419.92 5,510.58 5,616.46 

6,7 5,989.21 6,157.86 6,293.96 6,435.16 6,603.63 6,769.31 6,940.60 7,123.96 7,286.93 7,476.59 7,659.63 7,838.72 

8 2,936.30 2,999.47 3,061.14 3,144.25 3,208.44 3,263.76 3,322.21 3,362.06 3,416.20 3,483.80 3,550.74 3,613.71 

9 1,781.38 1,850.18 1,906.19 1,965.44 2,047.38 2,126.50 2,196.21 2,260.09 2,331.74 2,410.99 2,488.68 2,565.88 

10 1.45 

11,12 2,958.63 3,078.72 3,182.09 3,278.30 3,379.79 3,470.00 3,565.06 3,667.21 3,767.17 3,884.94 3,994.71 4,105.58 

141516 0.50 1.60 17 0.46 18 1,731.99 1,797.87 1,874.74 1,946.04 2,040.84 2,114.78 2,202.87 2,283.71 2,368.15 2,442.06 2,507.12 2,592.42 

19 7,895.94 8,156.88 8,420.82 8,734.72 9,095.69 9,449.17 9,803.25 10,155.49 10,469.13 10,732.07 11,024.89 11,317.31 1

20,21 1.45 25.40 49.88 87.21 119.38 162.56 215.53 270.30 352.61 429.72 502.59 584.19 

2223 252.75 738.84 1,172.75 24 276.33 791.23 1,302.29 1,932.94 2,591.91 3,165.02 3,910.89 4,674.38 5,444.82 5,993.35 6,492.64 

25 1,809.28 2,157.99 2,349.73 2,570.31 2,772.34 2,961.07 3,179.57 3,403.60 3,644.20 3,918.79 4,185.91 4,437.74 

26 3,156.53 3,320.02 3,489.59 3,655.31 3,842.08 4,021.64 4,234.23 4,449.59 4,640.20 4,823.00 5,030.26 5,230.80 27 4,602.62 4,786.35 4,979.05 5,173.67 5,371.07 5,556.68 5,789.77 5,989.44 6,166.09 6,350.05 6,558.83 6,768.83 28 2.42 4.42 6.93 12.51 17.20 22.74 30.87 37.85 50.35 65.88 83.60 102.75 303132 5.16 16.94 33 34 937.68 987.36 1,045.85 1,111.17 1,187.05 1,253.00 1,330.22 1,404.44 1,484.37 1,578.60 1,666.37 1,756.10 

35 3,368.07 3,564.56 3,789.87 4,013.26 4,248.20 4,368.11 4,582.97 4,765.20 4,985.08 5,208.41 5,456.20 5,672.51 

36 729.93 760.99 816.67 830.89 899.44 932.06 975.87 1,017.69 1,060.91 1,104.03 1,137.98 1,177.03 

37 2,030.17 2,149.46 2,281.05 2,407.93 2,533.18 2,639.07 2,798.33 2,925.84 3,087.23 3,231.03 3,388.31 3,529.17 

38 2,410.33 2,491.38 2,590.77 2,687.41 2,789.50 2,882.70 2,980.04 3,108.18 3,223.87 3,373.38 3,484.70 3,560.73 3940 953.09 1,033.74 1,113.72 1,196.08 1,278.97 1,373.34 1,448.75 1,551.85 1,662.98 1,773.33 1,903.14 2,033.93 

41 161.00 165.70 172.70 177.40 184.10 188.61 195.47 200.07 206.29 210.45 218.19 223.38 42 238.00 251.50 266.30 281.06 296.00 310.00 325.00 339.50 354.17 373.09 396.41 416.01 43 992.95 1,063.50 1,140.59 1,213.59 1,320.06 1,403.30 1,505.72 1,601.42 1,752.09 1,879.43 2,044.49 2,195.67 44 436.34 470.50 505.56 541.21 576.36 599.81 634.94 658.34 695.60 720.51 755.02 778.06 

45 185.10 221.25 260.28 291.51 317.24 344.67 372.51 404.80 434.88 467.40 500.28 46 36.05 55.10 79.66 96.05 111.25 121.40 136.93 147.27 162.02 171.87 184.69 193.27 47 25.99 43.31 86.24 114.87 148.00 170.12 195.96 213.19 227.63 237.27 48 0.45 1.66 2.46 10.50 33.96 56.35 77.36 106.01 123.82 139.73 153.47 49 4.23 26.75 41.79 54.92 63.67 505152

Total 51,477.37 54,438.69 57,471.90 60,528.12 64,036.61 67,223.47 70,657.63 74,176.75 77,894.54 81,872.66 85,906.76 89,759.81 9

Elevation (feet)

10-Foot contour Areas in Acres

Table 1 - 1935 Lake Mead Surface Areas (3 of 4). 
2001 Lake Mead Sedimentation Survey

32

 10-Foot contour Areas in AcresSheet No Elevation (feet)

1110 1120 1130 1140 1150 1160 1170 1180 1190 1200 1210 

1,2,3 376.42 464.77 548.47 643.40 738.41 842.71 949.69 1,064.19 1,175.46 1,336.17 1,510.52 

4 5,505.20 5,834.84 6,154.83 6,352.18 6,656.44 6,866.41 7,255.04 7,536.44 7,794.41 8,072.43 8,404.44 5 6,021.44 6,153.35 6,295.57 6,428.69 6,572.55 6,724.99 6,879.33 7,046.18 7,227.96 7,403.83 7,617.46 

6,7 8,384.30 8,549.14 8,714.64 8,890.94 9,051.65 9,249.34 9,403.96 9,591.52 9,788.03 9,965.52 10,177.46 

8 3,789.67 3,854.53 3,918.67 3,968.08 4,037.77 4,100.81 4,163.85 4,227.09 4,295.15 4,356.23 4,413.15 9 2,804.81 2,902.72 2,972.54 3,047.79 3,124.29 3,197.49 3,276.61 3,352.59 3,429.93 3,502.23 3,596.92 

10 7.39 9.59 13.57 16.39 19.61 24.95 32.11 39.74 47.56 54.63 65.87 

11,12 4,463.51 4,561.10 4,661.28 4,764.58 4,863.69 4,976.20 5,060.50 5,174.32 5,302.95 5,433.08 5,570.32 

14 

15 16 51.33 109.32 168.77 234.05 283.29 373.42 447.96 536.40 630.08 738.54 860.08 17 42.89 73.69 118.99 163.87 210.45 281.44 378.74 503.18 626.53 783.76 903.83 18 2,868.58 2,959.18 3,030.15 3,094.66 3,161.92 3,255.87 3,321.25 3,402.83 3,471.79 3,557.72 3,645.39 19 12,139.95 12,423.55 12,716.82 13,058.49 13,453.99 13,873.64 14,220.79 14,592.83 14,908.13 15,231.37 15,578.01 

20,21 811.45 877.79 951.29 1,046.21 1,153.23 1,308.33 1,478.00 1,657.03 1,798.93 1,945.96 2,192.31 

22 85.71 292.01 485.00 715.10 1,113.48 1,570.88 1,962.07 23 2,330.58 2,793.97 3,160.35 3,610.58 4,138.85 4,576.17 5,120.53 5,834.75 6,315.91 6,723.40 7,114.30 24 7,566.60 7,885.97 8,220.90 8,524.35 8,864.49 9,161.94 9,533.25 9,842.54 10,211.79 10,509.61 10,861.42 25 5,240.86 5,466.76 5,734.86 5,972.36 6,234.97 6,490.34 6,743.52 6,992.47 7,239.45 7,470.78 7,735.76 26 5,754.98 5,913.35 6,068.29 6,215.72 6,379.44 6,546.21 6,703.58 6,855.28 7,015.10 7,159.21 7,323.34 27 7,472.58 7,667.74 7,890.85 8,097.95 8,320.98 8,550.27 8,781.12 9,031.87 9,333.50 9,598.33 9,972.77 28 188.35 215.87 248.09 280.73 344.33 386.83 442.15 494.78 549.93 611.25 668.95 30 0.85 2.16 3.04 94.25 31 11.94 51.42 76.22 141.45 287.64 453.98 681.91 32 79.79 131.08 221.42 369.36 548.65 802.34 792.03 886.67 934.26 1,021.07 1,130.60 33 53.61 91.26 151.90 204.27 275.40 373.31 468.42 554.03 652.61 750.52 852.99 34 2,092.16 2,186.27 2,271.48 2,345.75 2,450.14 2,543.63 2,631.18 2,704.71 2,796.43 2,884.72 2,992.32 35 6,373.59 6,580.00 6,831.93 7,043.52 7,277.95 7,482.72 7,660.84 7,875.84 8,083.62 8,305.19 8,505.38 36 1,353.77 1,380.53 1,446.38 1,467.87 1,552.06 1,593.39 1,657.41 1,707.50 1,812.77 1,866.68 1,993.61 37 4,005.74 4,162.30 4,334.36 4,487.78 4,655.25 4,832.41 4,970.05 5,107.24 5,264.57 5,424.23 5,594.30 38 4,017.82 4,125.15 4,243.11 4,347.40 4,481.33 4,594.49 4,689.27 4,797.82 4,877.64 4,991.33 5,104.99 39 13.45 38.71 40 2,461.66 2,604.56 2,775.95 2,948.70 3,121.77 3,302.32 3,470.68 3,627.55 3,787.59 3,939.46 4,101.59 41 248.89 254.91 263.48 269.21 278.76 285.17 297.12 305.10 326.60 340.99 375.86 42 515.77 555.80 611.16 660.19 726.39 803.05 829.91 887.61 920.07 989.07 1,057.42 43 2,692.78 2,854.33 3,039.15 3,215.77 3,432.04 3,635.23 3,851.84 4,054.35 4,281.07 4,502.36 4,693.49 44 863.79 883.80 918.00 940.82 985.40 1,015.15 1,054.25 1,080.28 1,118.29 1,143.65 1,180.99 45 616.69 645.76 682.46 721.62 769.00 815.00 863.07 895.13 942.09 973.37 1,013.55 46 219.17 228.40 238.21 244.79 255.08 261.96 273.40 281.18 293.82 302.82 320.75 47 290.96 307.79 326.10 338.28 360.06 374.55 397.11 412.14 435.63 451.29 480.41 48 198.87 212.12 234.95 251.29 268.88 280.62 301.33 315.15 335.48 350.03 374.27 49 138.01 161.27 201.68 228.62 273.12 302.82 337.28 360.29 383.11 398.30 431.49 50 13.14 28.81 41.51 60.35 79.13 94.22 109.31 127.90 5152

Total 102,043.96 106,082.56 110,380.65 114,509.40 119,448.09 124,470.46 129,358.74 134,565.15 139,905.74 145,239.79 151,321.15 1

Table 1 - 1935 Lake Mead Surface Areas (4 of 4). 
33

1948-49 Lake Mead Sedimentation Survey

The purpose of the 1948 Lake Mead study was the collection of basic data in 

conjunction with previous pertinent data collected that permitted analysis of the 

effects of the development of this huge reservoir (USGS, 1960). The 1960 report 

is one of the most extensive on reservoir sedimentation and provides a summary 

of the collection, including extensive bottom sediment sampling, and the analysis. 

The survey and resulting analysis report was a collaboration of Reclamation, U.S. 

Department of the Navy, U.S. Department of Commerce, Coastal and Geodetic 

Survey, University of California, and Scripps Institution of Oceanography 

providing study results and future predictions. Considering the technology 

available, the 1948 Lake Mead sedimentation survey was an extensive effort. 

The echo-sounding equipment provided continuous sounding along designated 

lines that varied from 200 to 1,200 feet apart. Three different types of echosounders were used. A low enough frequency (14.25 kilocycles) depth sounder 

was used to determine the interface between the sediment deposition and the 

original bottom. In 1935, Lake Mead had a computed total capacity of 

32,381,780 acre-feet and a usable capacity of 29,177,249 acre-feet. By 1948, the 

total capacity had been reduced to 31,047,000 acre-feet and the average sediment 

inflow, 1935 through 1948, was computed to be 97,429 acre-feet. There are 

several facts within the report that were invaluable for the 2001 study: 

(1) The 1948 maximum measured sediment thickness in Pierce Basin was 270 

feet. The 2001 survey measured a similar thickness in Pierce Basin, but 

with the delta growth extending further downstream as well. 

(2) From the first 14 years of sediment inflow data it was estimated the 

reservoir would fill with sediment in the next four centuries. The 2001 

results showed that filling will be far beyond the predicted four centuries 

due to the closure of Glen Canyon Dam. 

(3) Sediment was confined almost entirely within the old river channel in 

1948. The 2001 survey confirmed that is still the case until the channel 

becomes completely inundated with sediment, causing additional 

inflowing sediment to settle parallel to the original river channel alignment 

in the deeper portions of the reservoir. 

(4) Sediment compaction will have an extremely important bearing on the rate 

of depletion of water-storage volume and life expectancy of the reservoir 

(USGS, 1960, page 217). The 2001 results documented this condition 

with the greatest effect in the lower reaches of the reservoir where the 

water is deepest. 

(5) Extensive sediment sampling program provided valuable information on 

the initial sediment deposition. 
2001 Lake Mead Sedimentation Survey

34

1963-64 (1963) Lake Mead Sedimentation Survey 

As part of the 1948 survey, Reclamation engineers concluded that Lake Mead 

should be resurveyed to coincide with closure of Glen Canyon Dam located about 

370 miles upstream of Hoover Dam (Lara and Sanders, 1970). The 1963 survey 

was similar to the 1948 survey and collected sufficient data to compute reservoir 

information below elevation 1,230. The biggest difference between the surveys 

was in the reservoir condition, the 1963 survey was conducted at much lower 

water content. 

The reservoir was divided into two areas and the hydrographic survey was 

conducted using different techniques. The main part of the reservoir from Pierce 

Ferry downstream to Hoover Dam was surveyed using echo-sounding equipment 

from elevation 1,150 and below. The exposed portions of the reservoir were 

measured by standard land and photogrammetric surveying procedures on the 

main part of the reservoir. The combined survey sets were used to develop new 

topography along with updated surface areas and volumes. 

The lower Granite Gorge area, from Pierce Ferry upstream, was surveyed by a six 

person crew resurveying the same 174 river sections surveyed in 1948. Of the 

174 range-lines, 148 were recovered and the other 26 were reestablished. The 

crosses marking each range-line were repainted for the recovered sections and 

new white crosses were painted for each of the reestablished ranges. The 2001 

survey computations relied on a biological monitoring program that collected 

cross sections in this reach. There were only ten cross sections for this large reach 

of the reservoir, but they were of adequate detail to estimate the volume there. 

The contour areas for the main reservoir at 10-foot contours below elevation 

1,150 were determined from the updated topographic sheets from the 1963 survey 

data. Portions of the 1935 topographic maps were used to trace contour areas 

above elevation 1,150. Each 10-foot contour on the topographic sheets was 

planimetered a minimum of three times to obtain an average surface area of the 

contours and additional checks were conducted to determine the accuracy of these 

initial planimetered results. 

The 1963 survey of Lake Mead was conducted primarily to determine the 

capacity of the reservoir along with volume loss since the original and 1948 

surveys. As part of the study, sediment samples were also collected. The study 

determined that since dam closure, the Lake Mead sediment accumulation was 

2,612,920 acre-feet. The annual sediment inflow during the 1935 through 1964 

period was computed to be 88,200 acre-feet. 
35

1998 Sediment Sampling 

In May 1998, the U.S. Geological Survey in cooperation with the University of 

Nevada, Las Vegas (UNLV) investigated rates of sediment deposition and 

concentrations of selected synthetic organic compounds at four sites within Lake 

Mead (Covay and Beck, 2001). Sediment cores provided data on deposition rates, 

age-dating, and chemical analyses of the collected samples. The collected cores 

ranged from 1.5 to 5 feet, providing information on the top layer of the sediment 

deposition. An extensive deep drilling program covering the entire sediment 

deposit would be necessary to obtain information on changes since the 1963 

sediment survey. The 1998 samples in the lower portion of the reservoir found 

sediment deposition was an ongoing process throughout the reservoir since 

closure of Glen Canyon Dam. 

The collected samples were described as saturated, medium saturation, or minimal 

saturation and some as silt core layers. The porosity was calculated for the cores 

in relationship to the sediment depth below the bottom surface. For the deep 

water sample at the Las Vegas Bay near the Colorado River confluence, the 

porosity at 2.5 centimeters was 0.79, at 102.5 centimeters 0.75, and at 127.5 

centimeters 0.38. For the sample at the Colorado River and Virgin River 

confluence, the surface porosity was 0.95 and at 113 centimeters 0.39. The 

deepest portion or bottom of the core may have been material from the original 

reservoir bottom, but it is assumed the layer consisted of consolidated sediment 

deposited previously. 

Biological Monitoring Cross Sections 

As part of a monitoring program, LCR had a biological contract for studying the 

Willow Fly Catcher. The monitoring included cross sections at 10 locations in the 

Lower Gorge Basin for determining the effect of the changing reservoir levels on 

the sediment formed banks used as bird habitat. The cross section locations 

started in the upper Pierce Basin and ended near Separation Canyon in the upper 

area of the Lower Gorge Basin. The LCR provided the data that included up to 

four different sets at some of the ten locations. During the later part of September 

2001, a collection trip was planned by the Sedimentation Group to collect 

additional data using RTK GPS and single beam sounder. After 9/11, this trip 

was cancelled since not all participants could get onsite to complete the data 

collection before the end of the month. A few days after 9/11, the biological field 

crew took this author to the ten cross sections during their collected trip. This 

provided a visual evaluation of the river throughout the Lower Gorge Basin that 

greatly helped during the analysis. A handheld GPS unit provided locations of the 

cross sections. 

The cross section data included one set from 1999 and up to three sets from 2001 

for the ten collection sites. The data files included distance and depth points, but 
2001 Lake Mead Sedimentation Survey

36

there was no vertical control near the study sites to tie the depths to the Lake 

Mead elevation datum. The 1999 data set was collected when the reservoir was 

nearly full, over elevation 1,205. For this analysis, elevation 1,205 was assumed 

as the vertical datum at each site for converting the 1999 depths to bottom 

elevations. The 2001 data sets were collected when the reservoir was at a lower 

level, meaning some of the locations were in a river condition and the reservoir 

elevation at the time of collection could not be used for depth to elevation 

conversion. For the 2001 data sets, comparison plots were developed with the 

1999 data set. Using common areas of the cross sections that did not appear to 

change over time, the 2001 cross section elevations were estimated from the 1999 

cross section data. These combined cross section results were used during the 

2001 analysis to estimate the loss of upstream reservoir area due to sediment 

accumulation. 

2000 Preliminary Meeting 

In July 2000, a preliminary meeting was held between Reclamation’s 

Sedimentation Group and LCR personnel in Boulder City Nevada to discuss the 

upcoming survey of Lake Mead that was to be funded in fiscal year 2001. The 

group also met with the USGS and UNLV study team that had been conducting 

extensive surveys on Las Vegas Wash and the lower portion of the reservoir since 

1999 (Twichell, 1999). In 2001, the USGS and UNLV collection was extended 

throughout the rest of Lake Mead accessible by the survey vessel utilizing low 

frequency single beam and side scan sounders (Twichell, 2003). 

Reclamation’s Sedimentation Group proposed to survey Lake Mead using a 

multibeam collection system. With the proposed limited budget it was decided to 

concentrate the collection along the original river channel alignment. Based on 

review of previous Lake Mead surveys and the experience of the Sedimentation 

Group on multiple reservoir surveys, such as the 1986 Lake Powell survey 

(Ferrari, 1988), it was assumed that the majority of change due to sediment 

accumulation on Lake Mead would initially occur along the original river channel 

alignment. The previous Lake Mead surveys documented the initial sediment 

filling the original river channel. As the sediment inflow continued, it buried the 

channel under accumulated sediment lying fairly flat from bank to bank. The 

2001 survey concentrated collection on these locations, making in-the-field 

decisions as to the extent of the outer boundary of the bottom measurements. 
37

2001 Lake Mead Field Survey 

Reclamation’s Sedimentation Group surveyed Lake Mead Reservoir in the spring 

of 2001 to develop a present storage-elevation relationship (area and capacity 

tables). This was the first multibeam survey conducted by the Sedimentation 

Group and the first known multibeam survey of Lake Mead. During the July 

2000 planning meeting, it was proposed to survey Lake Mead using 

reconnaissance techniques and a multibeam collection system that would map the 

known areas of sediment deposition (Ferrari, 2006). The Sedimentation Group 

has evaluated sediment on numerous reservoirs over the last century and based on 

experience, has modified collection and analysis techniques to obtain the best 

results within available budgets. Upon LCR approval for the Lake Mead survey, 

the multibeam collection system was requisitioned, providing one of the latest 

technologies for underwater collection. 

Previous surveys of Lake Mead in 1948 and 1963, the 1986 survey of Lake 

Powell, and numerous reservoir surveys conducted by the Sedimentation Group 

found the majority of sediment accumulates in the upper delta and deeper portions 

of the reservoirs along the original river channel alignment towards the dam. The 

2001 multibeam survey of Lake Mead focused on the original channel alignment 

to measure the known areas of sediment deposition. During the field collection, 

judgments where made as to the outer boundary of the existing sediments. The 

multibeam sweeps covered the sediment deposition and were extended beyond the 

deposition outer boundary to assure the bottom changes from the original 

topography were documented. 

The Lake Powell 1986 range line survey found the sediment distributed laterally 

across the original river channel alignment of the reservoir. Although a few of the 

Lake Powell range lines measured channel cuts through the deposited sediments, 

the majority measured the sediment lying horizontally in the deeper original river 

channel geometry (Ferrari, 1988). Between 1999 and 2002, extensive sidescan 

sonar imagery, seismic-reflection profiling, and bottom sampling were conducted 

on Lake Mead by the USGS from Woods Hole, Massachusetts and the Lake 

Mead/Mojave Research Institute out of the University of Nevada. There are 

numerous Lake Mead publications summarizing the methods of collection and 

results from these surveys and research. These studies noted the postimpoundment sediments mainly covering the floors of the former streambeds of 

Lake Mead with the remaining reservoir bottom consisting of rock outcrops with 

no major change due to sediment accumulation (Twitchel, 1999). 

The LCR Office contracted with the Sedimentation Group to conduct the Lake 

Mead 2001 survey with the primary objective to map the areas of sediment 

accumulation since closure of Hoover Dam in February of 1935. The underwater 

survey covered the known areas of sediment deposition accessible by the survey 
2001 Lake Mead Sedimentation Survey

38

vessel in 22 days during April and May of 2001. The LC Regional Office 

provided assistance during a large portion of the collection and conducted the 

Geographic Information Systems (GIS) analysis of the x, y, z multibeam data sets 

provided by the Sedimentation Group (LCR, 2003). In the fall of 2001, a limited 

aerial light detecting and ranging (LiDAR) survey was conducted in the Grand 

Bay and Pierce Basin area of the upper reservoir. Due to 9/11, a scheduled 

Sedimentation Group range line survey was not conducted in the lower Granite 

Gorge. Previous Lake Mead sediment surveys indicated a large portion of the 

reservoir was lost due to sediment deposition during initial filling in the 1940’s, 

but the upper elevation zones still had available area for water storage. The upper 

reservoir zone, from Pierce Basin upstream in the Lower Granite Gorge above 

elevation 1,180, is 40 miles of reservoir volume that was estimated in this study. 

The Lower Granite Gorge is narrow compared to the rest of the reservoir, but has 

available capacity as measured by the previous surveys of Lake Mead. The 

Sedimentation Group obtained data for this area through a contractor studying the 

effect of the reservoir on bird nesting areas along the Colorado River. Their study 

included cross sections, collected between 1999 and 2001, that were used to 

estimate the sediment accumulation in this reach of the reservoir at the time of 

this study. 

Prior to the underwater collection, a RTK GPS control survey with centimeter 

accuracy was conducted to establish a temporary horizontal and vertical control 

point near the Lake Mead Marina. This control point was used as the base of the 

RTK GPS system and was used for the survey of the lower portion of the 

reservoir in the Boulder Basin and Las Vegas Bay (figure 15). It was requested 

by the regional office that the horizontal control be established in UTM 

coordinates, Zone 11 in the North American Datum of 1983 (NAD83). A 

temporary control point was also established on the Overton Arm of the reservoir 

near Echo Bay Marina, but due to time limitations, a military issued GPS unit 

with horizontal accuracy of +4 meters was used to map the remaining portion of 

the reservoir. All depths were converted to elevations using reservoir water 

surface records tied to the Hoover Dam spillway datum. 

The 2001 survey utilized a high-resolution multibeam mapping system to collect 

x,y,z data of Lake Mead bottom from depths of 3 meters, in the upper portions of 

the lake, to greater than 140 meters near Hoover Dam. From the single transducer 

a fan array of narrow beams generated detailed cross sections of bottom geometry 

as the survey vessel passed. A 2-person crew that consisted of personnel from 

Reclamation’s Denver and Boulder City offices operated the boat and collection 

system with the Sedimentation Group as the lead of the field expedition. 
39

Figure 15-Lake Mead Basins, figure 3 from 2001 LCR report. 

Figure 15 is a map index from the 2001 LCR report. The different areas of Lake 

Mead were given the following designations for mapping purposes (LCR, 2003): 

• Area 1, x, y, and 2 – Boulder and Virgin Basins 

• Area 3a and 3b – Temple Bar and Virgin Canyon 

• Area 4 – Gregg Basin 

• Area 5 – Grand Bay Basin 

• Area 6 – Pierce Basin (not shown on figure 15) 

• Area 7 – Lower Granite Gorge Basin (not shown on figure 15) 

• Area 8a and 8b – Overton Arm 

Areas surveyed include the underwater river channels of the Las Vegas and 

Overton Arms along with the Colorado River channel from the dam to just 

downstream of Pierce Ferry where shallow depths prevented the survey vessel 

from proceeding further upstream. Limiting the survey to the areas of reservoir 

sediment deposition, significantly reduced the required collection time. For 

example, mapping the full extent of Las Vegas Wash would have taken many 

days to complete in detail with either a single or multibeam system. Since this 

study was mapping just the areas of sediment accumulation, the Las Vegas Wash 

area that included the large confluence as it entered the original Colorado River, 

was mapped in a little over one day’s time using the multibeam system. For the 

deeper portions of the reservoir, the procedure consisted of running parallel 

survey lines along the original river channel alignment. The distance between the 

parallel survey lines was depth dependent and was set to provide overlap of the 
2001 Lake Mead Sedimentation Survey

40

data sweeps. In the deepest water, one sweep from the system covered more than 

1,500 feet of the reservoir bottom. Parallel survey lines were run to ensure that 

complete mapping of the deposited sediments would be obtained in the deepest 

portion of the reservoir. As the survey vessels mapped the shallow water areas in 

the upper reaches of the reservoir, the overlap of the data sweeps was abandoned 

due to the time it would have taken to ensure full bottom coverage. Since the 

sediment deposits in the upper reaches were measured flat, it was determined that 

the areas missed could be projected during analysis. The areas covered by the 

2001 survey are plotted within basins on figure 16. The figure was generated for 

the LCR 2001 report using the same basin boundaries as the 1948 and 1963 

studies (LCR, 2003). Appendix I provides more detail of the basin and the 

mapping boundary outlines. 

Figure 16 - 2001 Lake Mead bathymetry data sets, figure 2 from LCR 2001 report. 

The multibeam survey measured the majority of the sediment deposits lying very 

flat. Due to the flat lying sediment, the collection speed could have been 

increased and the amount of overlap of the collection profiles could have been 

reduced without affecting the quality of the data collection and final analysis 

results. However, since this was the first multibeam survey performed by the 

Sedimentation Group, an extensive overlap of the profiles was maintained and the 

collection speed was held below seven miles per hour to provide quality 

assurance. During data processing, it was found that one multibeam profile 

happened to map an area of the Overton Arm of Lake Mead where a B29 military 

aircraft had crashed in 1948. A private diving team conducting research and 
41

sidescan collection pinpointed the location of the B29, where it was found to have 

settled on a ridge just above the original Overton River channel, (B29, 2002). 

The plane was found in around 300-feet of water and pictures from the dive team 

clearly show images of the plane and interior instruments with little or no silt 

material. These images further indicate the inflowing sediments travel along the 

original river channel alignment where they first settle in the deeper portions of 

the original river alignment. Figure 17 is an unfiltered image from one profile of 

the multibeam collection system revealing the general outline of the plane. A 

more detailed image could have been generated by the multibeam system if more 

profiles would have covered the aircraft. 

Figure 17 - B29 Multibeam image from Lake Mead, developed by LCR. 

Due to shallow depths, the upper reservoir area on the Colorado River could not 

be surveyed by the large survey vessel. Part of the data collection plan was to 

survey the reach from Pierce Ferry upstream to Separation Canyon using aerial 

LiDAR (Light Detection and Ranging). Since air space access to the Grand 

Canyon portion of this reach could not be obtained from the National Park 

Service in time, the LiDAR collection was limited to the Pierce Basin area 

covered by the National Park Service within the Lake Mead boundary. The aerial 

survey was conducted in September of 2001 measuring no area from elevation 

1,180 and below and no major change from original from elevation 1,200 and 
2001 Lake Mead Sedimentation Survey

42

above. Surface areas at elevation 1,190 were generated by GIS methodology and 

were part of the final 2001 area and capacity calculations by the Sedimentation 

Group. 

Future collection should consider airborne LiDAR hydrographic surveying as a 

method for collecting above and below water data. The Sedimentation Group and 

other agencies have successfully used the bathymetric LiDAR method to conduct 

shallow water river surveys (Hilldale, 2004). The primary constraint of this 

method is water clarity. This method has been successful at collecting depths of 2 

to 3 times the visible depth through as much as 60-meters of clear water. In more 

turbid waters such as Lake Mead, the collection would have to be timed for ideal 

conditions. Utilizing bathymetric LiDAR combined with underwater collection 

methods such as multibeam, complete coverage could be obtained, resulting in the 

most accurate reservoir topography. 

Since the LiDAR was limited to the Pierce Basin area only, the Sedimentation 

Group proposed to survey the reservoir area from Pierce Basin upstream by the 

range line method using RTK GPS and a single beam depth sounder. The survey 

was scheduled for the middle of September 2001 using available end-of-the-year 

funds. Due to 9/11, the trip was delayed and eventually canceled when it was 

determined the trip could not be completed before the end of the budget year on 

September 30, 2001. 

Previous Lake Mead sediment surveys in the 1940’s and 1960’s indicated a large 

portion of the upper reservoir area on the Colorado River was lost due to sediment 

deposition, but the survey results did show some upper elevation zones were 

available for water storage. The upper zone, from elevation 1,180 and above, is 

40 miles of reservoir volume that was accounted for by this analysis. This area, 

named Lower Granite Gorge, is narrow compared to the rest of the reservoir, but 

still has available capacity. 

Data for the lower Granite Gorge area of the Colorado River were obtained 

through cross section surveys, collected between 1999 through 2001, by a 

biological contractor studying the reservoir effects on the nesting areas of 

Southwester Willow Flycatcher birds. Part of the monitoring program was the 

survey of ten cross sections from Pierce Basin to Separation Canyon. The cross 

sections general horizontal locations were tied to absolute GPS measurements 

with the elevations tied to the measured Lake Mead water surface at time of the 

survey. The Sedimentation Group developed cross sections with elevations from 

all available information for the ten locations. The reservoir elevation during the 

cross section surveys varied from elevation 1,190 to over 1,200. Overlapping 

plots of the cross sections allowed judgments to be made as to the true reservoir 

bottom elevations for each cross section location. This cross section data was 

used to estimate the area lost for this entire reservoir reach from Pierce Basin to 

Separation Canyon due to sediment accumulation. 
43

2001 Lake Mead Analysis 

The initial processing of the 2001 multibeam data was conducted after each day’s 

collection by the Sedimentation Group. This included computer backup and 

visual inspection to assure system components were working properly. Upon 

completion of 2001 Lake Mead underwater collection, intense processing of the 

entire data set was conducted by the Sedimentation Group. This included 

applying the motion sensor measurements, the reservoir water surface elevations, 

and the sounding velocity profile files to correct the depth soundings to compute 

true lake bottom elevations. The editing processing was conducted in phases. 

The first phase consisted of viewing and editing the tide, heave, pitch, roll, 

heading, sound velocity, and positioning data. The second phase provided views 

of the multibeam sweeps that allowed editing of the individual points. The third 

phase sorted the data into matrix files that allowed multiple overlapping sweeps to 

be viewed and further edited. All elevation data were tied to the Hoover Dam 

powerhouse datum that is 0.55 feet lower than NGVD29 (Lara and Sanders, 

1970). 

To make the massive amount of multibeam underwater data more manageable, a 

filtering routine was applied within the analysis software during initial processing. 

This was accomplished by sorting the data into grids or cells and saving the 

maximum depth within each cell at its actual measured location. For the narrow 

canyon reach from the dam upstream to where it widens in Boulder Basin, the 

grid size was 2 meters. For the rest of the reservoir, the grid size was set at 5 

meters. Quality control and assurance of the data set was provided by conducting 

field calibration as required by the multibeam system and comparing the final 

elevations to other independent data sets. The final 53 data sets included 20 

million x,y,z points that covered about 30 percent of the underwater portion of 

Lake Mead (LCR, 2003). 

At the first part of July 2001, these final processed x,y,z data files were forwarded 

by the Sedimentation Group to the GIS Branch of the LCR Boulder City Office 

for topographic development. Following is a summary of the LCR analysis report 

located in Appendix VII (LCR, 2003). The report outlines the topographic map 

processing and lists where the processed data can be obtained. 

Topographic Processing by LCR 

The LCR processing generated original (1935) and 2001 reservoir bottom 

topography within the individual map sheet boundaries as defined by the 1963 

Lake Mead survey report (Lara and Sanders, 1970). The boundaries for all 45 

maps are shown on figure 18, listed as maps 1 through 52 with no map 13 and 29. 

In some cases, single maps were labeled with multiple numbers: 1-2-3, 6-7, 11-

12, and 20-21. Appendix I has a breakdown of the basins by map boundaries 

initially developed for the 1948 and 1963 studies and used by this study for the 
2001 Lake Mead Sedimentation Survey

44

2001 analysis. All horizontal data for the 2001 study was collected and processed 

in the UTM Zone 11 North in NAD83 coordinated system with the map 

boundaries cut along the original UTM grid lines with elevations tied to the 

project or Hoover Dam’s power house vertical datum in meters. 

Figure 18 - Map sheet boundaries, figure 4 of 2001 LCR report. 

Generating the 1935 Topographic Surfaces 

The GIS analysis of the Lake Mead bathymetry began with the regeneration of the 

1935 or original surface area topography using ARCGIS routines and tools (ESRI, 

2001). The original topography was regenerated from the Lake Mead 10-meter 

digital elevation model (DEM) USGS quadrangle maps. The original DEM 

topography information was only available from Pierce Basin downstream to 

Hoover Dam. These USGS quadrangle map contours were developed from the 

original, 1935, five and ten foot original reservoir contours and presented as 10-

meter DEM’s. The USGS quadrangle maps are available above Pierce Ferry, but 

were developed from aerial data collected after closure of Hoover Dam and after 

this portion of the reservoir area had been dramatically altered due to sediment 

deposition. 

For the purpose of comparing results with the original Lake Mead information, all 

ARC GIS data in metric units were converted to English units. The resulting 

individual map areas and volumes were consistently within 2 percent or less of 

the original published values listed in the 1963 report. This close correlation of 
45

surface area values validated the use of USGS DEM’s as a reasonable method of 

computing the original and 2001 area and capacity values for the individual maps 

where both data sets were available in a digital format. The LCR analysis 

computed the 2001 capacity and resulting sediment deposition assuming no 2001 

reservoir volume, or complete loss of capacity, from Pierce Basin upstream due to 

aggradation (LCR, 2003). 

The LCR study developed spread sheets for comparison of the original and 2001 

values for maps 1 through 41 (figure 18). Their analysis did not include map 30 

located in the upper Overton Arm reach, but since the analysis made comparison 

of only the maps with available data this was not an issue. Following are 

comparisons of GIS computed surface areas for the original and 1963 studies: at 

elevation 1,230 the GIS computed area was 149,882 acres compared to the 

original published surface area of 152,233 acres, or 1.5 percent less; at elevation 

1,100 the original surface area was 92,702 acres compared to the GIS surface area 

of 91,574 acres or 1.3 percent less; at elevation 1,000 the original surface area 

was 58,090 acres compared to the GIS area of 57,728, or 0.7 percent less. 

Comparison of the 2001 GIS developed original capacity values and the original 

capacity values published in 1963 for maps 1 through 41 at elevation 1,229.0 

shows nearly 252,000 less acre-feet than the original published capacity values, 

about a 1 percent difference. This comparison indicates that the computed surface 

area values are slightly less, but very close to the original values. For computing 

the total sediment deposition, the original and 2001 GIS developed values were 

compared for differences. The principle limitation of the GIS comparison 

approach was that the original maps could not be regenerated for the entire 

reservoir. The main portion of the reservoir without original DEM data was from 

Pierce Basin upstream, which also happens to be the area of the reservoir 

impacted the most by sediment deposition. This is the main reason that it was 

assumed no 2001 capacity existed in these upstream basins. 

Generating the 2001 Surfaces by LCR 

The LCR analysis generated the 2001 contours and resulting surface areas for 

each available map sheet by combining the original DEM with the 2001 bottom 

elevation data. Using the original DEM’s for the individual sheets, the 2001 

underwater data was merged within the original map DEM by deleting the 

underlying original points. The resulting TIN contours and surface became the 

2001 Lake Mead TINs, contours, and computed surface areas for the maps with 

original DEM data and 2001 collected data sets. These were the map sheets, 

along the original map boundaries, used for this analysis. It was assumed that the 

original map areas outside of the 2001 collection data remained unchanged. 

Using ARC GIS tools, surface areas were calculated from the developed TIN’s. 

The surface areas were calculated in metric units in vertical increments to match 

the 10-foot contour interval of the original. Surface areas were computed using 

the ARC GIS volume command with the option to calculate the area and volume 
2001 Lake Mead Sedimentation Survey

46

below the given elevation. The resulting 2001 surface area values, at 10-foot 

increments, were imported into a spread sheet in square meters and converted to 

acres to match the units in Table 3-3 of the 1963 survey report. 

LCR Volume and Sediment Computations 

The 2001 LC Regional Office analysis assumed the original reservoir area above 

Pierce Basin was totally filled with sediment, meaning as of 2001 there was no 

available reservoir capacity there. The 1948 and 1963 survey results found that 

the majority of this area was silted in, but as seen on the longitudinal profile and 

cross section plots for these studies, there are over 40 miles of upper reservoir 

area from elevation 1,180 and above with available reservoir space. Portions of 

the upper elevation zones showed little to no measured sediment accumulation. 

Since there was no original DEM or 2001data available for this area of the 

reservoir, the LCR assumption of no 2001 capacity was valid for their sediment 

analysis. 

Table 2 is a summary of the LCR Lake Mead capacity by reservoir basin, for the 

1935 and 2001 results. As seen on the table, the 2001 capacities were set at zero 

for the Pierce and Lower Granite Gorge basins. The 1935 listed capacities for 

these basins are from the 1963 report and the last column shows the total capacity 

for the listed years. At elevation 1,230, the original 1935 capacity of 32,547,000 

acre-feet is around 1 percent greater than the combined GIS 1935 values 

computed in the LCR analysis. This is a good comparison for the use of the DEM 

data with a total capacity difference between the two different computational 

approaches of over 250,000 acre-feet at elevation 1. The LCR sediment 

deposition value compared the GIS 1935 value to the 2001 computations was 

explained previously. At elevation 1,230 the computed sedimentation deposition 

was 2,675,382 acre-feet for the 66.7 years of reservoir operation since Hoover 

Dam closure. 

As part of the LCR analysis a cooperative agreement was entered into with the 

USGS and University of Las Vegas. The agreement included the sharing of the 

Sedimentations Group’s processed data and analysis time. The extensive data sets 

from the LCR/USGS processing are available online. The web site is titled 

“Mapping the floor of Lake Mead (Nevada and Arizona).” The site contains 

preliminary discussion of their processing methods and the link to the released 

GIS data sets processed by LCR. The online report is labeled, USGS Open-File 

Report 03-320, authored by David C. Twichell and VeeAnn A. Cross of the 

USGS and Stephen D. Belew of Reclamation. 

http://pubs.usgs.gov/of/2003/of03-320/htmldocs/contents.htm

 
47

Elevation Boulder and Virgin Basins Temple Bar/ Virgin Canyon Gregg Basin Grand Bay Pierce Basin Lower Gran

1935 2001 1935 2001 1935 2001 1935 2001 1935 2001 1935 

660 1,000 0 0 0 0 0 670 7,000 0 0 0 0 0 680 21,000 0 0 0 0 0 690 43,000 0 0 0 0 0 700 73,000 1 0 0 0 0 

710 111,000 26 0 0 0 0 720 156,000 202 0 0 0 0 730 207,000 5,199 0 0 0 0 740 265,000 28,417 0 0 0 0 750 336,000 67,440 0 0 0 0 760 422,000 121,482 1,000 0 0 0 0 770 518,000 185,741 3,000 0 0 0 0 780 626,000 260,074 7,000 0 0 0 0 790 745,000 349,344 15,000 0 0 0 0 800 877,000 465,444 27,000 0 1,000 0 0 0 810 1,026,000 609,651 41,000 0 2,000 0 0 0 820 1,189,000 772,023 57,000 311 3,000 0 0 0 830 1,365,000 948,535 76,000 3,383 7,000 0 0 0 840 1,553,000 1,137,661 95,000 11,856 15,000 0 0 0 850 1,755,000 1,338,350 116,000 26,439 28,000 0 0 0 860 1,970,000 1,553,308 139,000 46,118 46,000 3 1,000 0 0 870 2,197,000 1,780,139 164,000 70,271 68,000 14 2,000 0 0 880 2,437,000 2,016,372 191,000 97,383 92,000 312 5,000 0 0 890 2,690,000 2,266,939 220,000 126,993 120,000 1,468 9,000 0 0 900 2,955,000 2,532,757 251,000 159,127 150,000 5,661 15,000 0 1,000 0 910 3,234,000 2,809,297 285,000 193,250 182,000 15,381 21,000 0 3,000 0 1920 3,529,000 3,098,525 321,000 229,529 215,000 29,891 29,000 0 6,000 0 4930 3,837,000 3,408,734 360,000 268,951 251,000 48,994 38,000 0 11,000 0 7940 4,161,000 3,729,848 401,000 310,657 291,000 72,132 47,000 0 16,000 0 11950 4,498,000 4,060,698 445,000 354,469 332,000 99,441 57,000 0 22,000 0 16960 4,851,000 4,411,053 491,000 401,683 375,000 130,911 67,000 0 29,000 0 22970 5,218,000 4,773,929 540,000 451,295 419,000 165,932 79,000 0 36,000 0 29980 5,598,000 5,146,619 591,000 502,870 467,000 204,436 91,000 0 44,000 0 37990 5,994,000 5,539,157 647,000 558,125 516,000 247,432 104,000 0 52,000 0 48

1000 6,405,000 5,949,161 705,000 616,882 567,000 294,171 118,000 0 61,000 0 591010 6,832,000 6,371,475 766,000 678,198 621,000 343,577 132,000 0 71,000 0 731020 7,275,000 6,810,939 830,000 742,827 678,000 396,076 148,000 0 81,000 0 871030 7,735,000 7,272,098 899,000 811,669 736,000 452,414 166,000 0 91,000 0 1031040 8,212,000 7,746,866 969,000 883,214 797,000 511,422 184,000 0 103,000 0 1201050 8,704,000 8,234,073 1,043,000 957,244 861,000 572,816 204,000 0 117,000 0 1381060 9,214,000 8,745,095 1,121,000 1,035,952 928,000 638,896 224,000 0 131,000 0 1591070 9,739,000 9,271,537 1,202,000 1,117,814 998,000 707,989 247,000 0 146,000 0 1811080 10,281,000 9,806,529 1,288,000 1,201,761 1,069,000 779,053 271,000 0 163,000 0 2041090 10,841,000 10,366,905 1,377,000 1,291,333 1,144,000 855,132 296,000 0 181,000 0 2281100 11,418,000 10,943,941 1,470,000 1,384,839 1,222,000 934,789 323,000 0 200,000 0 2551110 12,013,000 11,531,586 1,567,000 1,480,933 1,303,000 1,017,119 352,000 6 222,000 0 2821120 12,625,000 12,143,336 1,669,000 1,581,944 1,387,000 1,104,654 383,000 346 244,000 0 3111130 13,256,000 12,772,751 1,775,000 1,686,792 1,474,000 1,196,037 415,000 1,223 268,000 0 3421140 13,904,000 13,416,975 1,885,000 1,794,681 1,564,000 1,290,126 450,000 5,179 293,000 0 3751150 14,569,000 14,077,141 1,999,000 1,905,641 1,656,000 1,386,788 488,000 15,307 319,000 0 410

1160 15,254,000 14,766,195 2,116,000 2,021,194 1,752,000 1,487,286 527,000 32,248 349,000 0 447

1170 15,959,000 15,468,756 2,239,000 2,139,245 1,851,000 1,589,795 570,000 58,962 378,000 0 486

1180 16,685,000 16,182,627 2,365,000 2,259,375 1,951,000 1,693,943 613,000 91,313 411,000 0 526

1190 17,432,000 16,930,140 2,495,000 2,384,444 2,055,000 1,802,251 660,000 131,473 445,000 0 5691200 18,197,000 17,695,217 2,630,000 2,512,678 2,161,000 1,913,578 708,000 174,034 481,000 0 6141210 18,984,000 18,475,718 2,769,000 2,643,844 2,270,000 2,027,725 758,000 218,686 519,000 0 6611220 19,797,000 19,283,171 2,912,000 2,779,228 2,381,000 2,145,561 812,000 265,371 558,000 0 7101230 20,632,000 20,111,593 3,059,000 2,917,917 2,495,000 2,266,010 867,000 313,681 600,000 0 760

* Original capacity from 1963-64 study. ** GIS computed capacity execpt for Grand Bay, Peirce, and Lower Granite Gorge Basins. 
2001 Lake Mead Sedimentation Survey

48
49

Generating the 2001 Surface Areas by the 

Sedimentation Group 

During the 2001 Lake Mead study, the Sedimentation Group recommended a 

slightly different approach to the data analysis, but time and budget constraints 

prevented the recommended analysis from being performed at that time. After the 

LCR analysis was completed, the Sedimentation Group was able to acquire staffdays and funds to cover a portion of the alternative analysis presented here. The 

primary concern of the Sedimentation Group was the measurement of bottom 

elevations in 2001 being lower than the 1963 bottom elevations measured in the 

Boulder, Virgin, and Temple Bar Basins. For most studies, measuring lower 

elevations than previous surveys usually indicates an error in the survey, but later 

investigations by the Sedimentation Group supported the 2001 Lake Mead survey 

results. Rather than assuming zero reservoir capacity above Pierce Basin (as was 

assumed in the LCR analysis), the Sedimentation Group proposed to use available 

data to estimate the 2001 reservoir capacity in the upper basins. The 

Sedimentation Group was not questioning the results or approach of the LCR 

analysis, but took different approaches to address the question of the increase 

capacity in the lower elevations of the reservoir since 1963 and to include the 

available capacity of Lake Mead from Pierce Basin upstream. 

In 2005-2006, the Sedimentation Group developed reconnaissance techniques for 

reservoir surveys that provided additional analysis of the 2001 Lake Mead results 

(Ferrari, 2006). Upon completion of the 2006 report, and when time allowed, a 

more detailed analysis of the Lake Mead data was conducted by the 

Sedimentation Group. Following is a summary of surface area and resulting 2001 

Lake Mead capacity computations from the additional analysis. The 

Sedimentation Group’s methodology differed from the LCR procedure in that the 

analysis was conducted map by map for the entire reservoir using all available 

data and previous experience to generate a 2001 Lake Mead area and capacity 

table along with resulting sediment computations. The approach looked for 

change from the original measured surface areas due to sediment deposition and 

did not make the assumption that the upper reservoir area from Pierce Basin 

upstream had completely filled with sediment leaving zero capacity there. The 

original individual map surface areas at the 10-foot elevation increments, as 

documented in the 1963 report, were used for the analysis. If the 2001 data 

indicated no change due to sediment at the original 10-foot contour interval, the 

contour surface area was marked as no change and the original surface area value 

from the 1963 report was used for the individual zone being analyzed. 

The Sedimentation Group received the initial processed data set from LCR in 

spring 2002, prior to a meeting that was held in Boulder City between 

Reclamation and the USGS. The USGS conducted the Lake Mead survey using 

different collection technology and had been working with the LCR on data 
2001 Lake Mead Sedimentation Survey

50

processing (Twitchel, 1999). The LCR also developed digital images from the 

2001 multibeam data, figures 19 and 20. The images were developed using only 

the 2001 multibeam x,y,z data of the Colorado River data from Hoover Dam to 

about one mile upstream. The data set was filtered into 2-meter grids for this 

reach of the reservoir. Due to the extreme size of the data sets, the majority of the 

2001 multibeam data was filtered into 5-meter grids for the LCR processing, but 

in the dam channel reach, the grids were set smaller to obtain more detail of the 

vertical wall topography. The first image (figure 19) shows the cofferdam located 

just upstream from the dam face and the second image (figure 20) shows the base 

of two intake towers located on the left bank looking towards the dam. The top of 

the cofferdam was not expected to be exposed within the image as previous 

survey results of the river thalweg showed the cofferdam completely buried by 

sediment deposition. A literature search on the construction of Hoover Dam 

uncovered a design drawing with the top of the cofferdam labeled elevation 720. 

Figure 19 -Multibeam data of Colorado River upstream of Hoover Dam. 

Cofferdam 

Hoover Dam 
51

 

Figure 20 - Multibeam generated image of Hoover Dam and intake towers. 

Upon receiving the data set from the LCR in spring 2002, a few days were spent 

evaluating the data and results prior to the scheduled meeting with the USGS. 

Using ARC GIS tools and the 2001 developed TIN’s, a crude longitudinal profile 

was developed for the Colorado River, Las Vegas Wash, and Overton Arm of 

Lake Mead. These plots provided visual images of changes that had occurred 

since the original profiles were surveyed. For the meeting, the 2001 thalweg 

profile of the Colorado River was plotted against previous surveyed profiles from 

the 1963 report. There was not enough time prior to the meeting to conduct 

further analysis, but the thalweg plots generated considerable discussion. The 

main item of interest was the 2001 Colorado River thalweg plotted at a lower 

elevation than the previous survey data in the lower reaches of the reservoir. 

After the Boulder City meeting, the longitudinal profiles were electronically 

generated and presented in this report. Figures 21 and 22 contain the longitudinal 

profiles measured for the 1935 (original) and 2001 data for Las Vegas Wash and 

the Overton Arm of Lake Mead. Both of these tributary plots show the thalweg 

change, over 66 years of reservoir operations, due to sediment accumulation from 

the respective drainage basins. The profiles show the classic build-up of the 

Intake Towers 

Hoover Dam 
2001 Lake Mead Sedimentation Survey

52

sediment delta in the upper basin area and the accumulation of sediments in the 

lower basin area at the confluence with the Colorado River. As shown previously 

on the Grand Bay drainage basin, the sediment barrier at the confluence consisted 

mainly of Colorado River drainage basin sediments. If the reservoir were to 

significantly drop in elevation, these deposited dikes, dams, or sediment plugs 

could hold back the waters in the tributary basins, forming a separate water body 

from Lake Mead. These barriers would also affect any density currents within 

these drainages and would likely remain intact until tributary inflows were great 

enough to overtop and erode the sediment barrier. Further investigation of the 

formation of these barriers would be necessary to determine their full effect. 

The thalweg plots show the minimum build up of sediment in the Overton Arm 

and Las Vegas Wash tributaries since closure of Hoover Dam and provide 

evidence of the total amount of sediment the Colorado River has contributed to 

Lake Mead. As illustrated on these plots, the total sediment contribution from the 

tributaries is minimal compared to the Colorado River drainage. Studies of the 

sediment yield of Las Vegas basin to Lake Mead have confirmed that the 

contribution is minimal compared to the Colorado River source prior to and even 

since the closure of Glen Canyon Dam. Since the closure of Glen Canyon Dam in 

1963, the main source of Lake Mead sediments has been significantly reduced. 

The Colorado River thalweg plot showed a build up of the upper delta for all 

surveys and with this information a better estimate of the total amount of 

sediment contribution during the survey periods could be generated. Also 

numerous studies in the Grand Canyon have documented the area below Glen 

Canyon Dam as being sediment deprived. Information from these studies could 

be used to better estimate and understand the current sediment inflow to Lake 

Mead. 
53

Las Vegas Wash Longitudinal Profiles

1935 and 2001 Comparison

650700750800850900950

100010501100115012001250

10 9 8 7 6 5 4 3 2 

Distance Upstream of Confluence (miles)

Elevation (feet)

2001 Survey1935 Original Survey

Figure 21 - Las Vegas Wash longitudinal profile.
2001 Lake Mead Sedimentation Survey

54

Overton Longitudinal Profiles

1935 and 2001 Comparison

650700750800850900950

100010501100115012001250

40 35 30 25 20 15 10 

Distance Upstream of Confluence (miles)

Elevation (feet)

2001 Survey1935 Original Survey

Figure 22 - Overton longitudinal profile. 
55

550600650700750800850900950

100010501100115012001250

120 110 100 90 80 70 60 50 40 30 20 

Distance Upstream of Dam (miles)

Elevation (feet)

2001 Survey1963 Survey1948 Survey1935 Original Survey

Virgin Basin Boulde

Canyo

Temple Bar Area Virgin Canyon

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

Greg BasinIcebergCanyon

Grand Bay

PierceBasin

Lower Granite Gorge

Figure 23 - Colorado River longitudinal profile. 
2001 Lake Mead Sedimentation Survey

56
57

The Colorado River longitudinal profile on Lake Mead compares the 1935, 1948, 

1963 and 2001 survey results, figure 23. The 2001 profile of the Lower Granite 

Gorge above Pierce Basin was developed from the cross section data collected by 

the LCR biological contractor studying the effect of the upper reservoir on bird 

nesting habitat. Ten cross sections representing the gorge were collected by the 

biologists without a true vertical datum, but based on previous experience and 

knowledge of the reservoir delta formation relative to pool elevation; the cross 

sections were adjusted to complete the thalweg profile from Pierce Basin 

upstream. About 40 reservoir miles were developed from the cross sections 

where the reservoir boundary is confined to a narrow corridor by the natural 

topography until it widens out into Pierce Basin. The majority of the upper delta 

first began to develop at the Pierce Basin expansion due to the drastic decrease in 

river velocity. The Pierce Basin area was covered by the 2001 LiDAR collection, 

providing the Sedimentation Group with an accurate representation of the delta 

development as of September 2001 for their analysis. The 1948 and 1963 

longitudinal profiles were developed by scaling the distance and elevation from 

the longitudinal profiles presented in the 1963 study report. 

The Colorado River longitudinal plot revealed some interesting results. The 2001 

bottom data plotted lower than the 1948 and 1963 longitudinal profiles in the 

lower reservoir area from Hoover Dam upstream. The 1963-64 thalweg plotted 

lower than the 1948 thalweg for the first six miles upstream of the dam and in the 

very upper end of the reservoir within the Lower Granite Gorge basin. The lower 

1963 thalweg elevation at the dam indicated sediment consolidation between the 

two surveys. The 1963 survey was conducted when the reservoir pool was much 

lower than the 1948 survey. Due to the lower reservoir condition, a portion of the 

sediment deposition in the upper reach measured in 1948 was eroded and carried 

further downstream, moving the upper sediment delta pivot point downstream. 

During the processing of the data, prior to the spring 2002 meeting, it was 

discovered that the 2001 map boundaries did not match the original map 

boundaries. This did not affect the development of the longitudinal profiles, but it 

did impact the computed surface areas and resulting capacities when comparing 

the original and 2001 results. The 2001 map boundaries were regenerated by 

LCR and forward to the Sedimentation Group in September of 2002. Data 

showing the measured 2001 bottom elevations lower than the previous two 

surveys was presented at the spring 2002 meeting, but at that time no clear 

explanation had been formulated. There was some discussion of potential depth 

errors in the previous surveys, but this author took the approach of confirming the 

accuracy of the 2001 data first. 

Upper Reservoir Delta Deposition and Formation 

Several publications that describe the general formation of sediment deltas within 

reservoirs used previous surveys of Lake Mead to generate conclusions (Fan and 

Morris, 1992; Strand and Pemberton, 1982). Reservoir deltas typically grow in 
2001 Lake Mead Sedimentation Survey

58

the downstream direction, but fluctuating reservoir operations can result in 

vertical and upstream growth dependent on the normal reservoir operational water 

level. The original upstream area of Lake Mead was shallow with little storage 

capacity compared to the rest of the reservoir. During initial filling in this zone of 

the reservoir, the longitudinal growth of the delta was very rapid. The Colorado 

River longitudinal plot in figure 23 shows that the elevation of the upper delta 

formation for the different surveys was affected by the normal annual reservoir 

operation level. The 1963 survey was conducted at a lower normal pool elevation 

than the 1948 survey. Prior to the 1963 survey, the reservoir pool started to drop 

and the upper reservoir began functioning in a river condition, eroding a portion 

of the previously deposited sediments and transporting them downstream where 

they eventually deposited at the new normal reservoir pool elevation. The 

Colorado River longitudinal plot in figure 23 shows the 1963 upper profile 

plotting lower than the other surveys due to the lower mean or normal reservoir 

water level and subsequent bed erosion. The Lake Mead delta falls along the 

typical delta formation pattern with an abrupt change between the slope of topset 

and foreset deposits, figure 9. Reservoir bottom sampling conducted for the 1948 

study identified a corresponding abrupt change in particle diameter between the 

coarser topset and finer foreset deposits, figure 24 (USGS, 1960). The sediment 

information indicated that as the upper delta formed and eroded due to reservoir 

operations, the upper delta and delta face grew downstream and consisted of 

heavier sand, gravel, and cobble material. The 1998 USGS sampling program in 

the deeper, lower reach of the reservoir found the top sediment layer consisted of 

unconsolidated silt deposits. 

Figure 24 - Reservoir sediment density location zones (1935 to 1948). 
59

2001 Measured Depth Analysis 

Reservoir bottom elevations measured along the downstream portion of the 

original river channel alignment during the 2001 survey were lower than those 

measured during the previous two surveys in 1948 and 1963, figure 23. 

Measuring lower elevations than previous surveys typically indicates a data 

collection or analysis error, but investigation by the Sedimentation Group 

supported the 2001 bottom elevation results. Investigations included checks of 

the quality of data collected by the previous surveys and comparison of the 2001 

elevations with known elevations such as the base of the intake towers and the top 

of the cofferdam. The 2001 bottom data results were also compared with other 

independent depth measurements to further support the 2001 multibeam bottom 

results. These analyses concluded that over time, compaction of the previous 

measured accumulated bottom sediments had occurred, resulting in the lower 

2001 measured elevations. Mathematical means have been developed to compute 

the compaction rate that occurs overtime and are presented in the Consolidation of 

Bottom Sediments section of this report (Strand and Pemberton, 1982). Appendix 

II contains example comparisons of the 2001 depth measurements to other 

available information that resulted in further confirmation of the 2001 depth 

results. 

According to Hoover Dam design drawings, the toes of the intake towers are 

around elevation 894. The 2001 multibeam elevations match very well with the 

design drawings, such as Reclamation drawing 45-D-13857. One elevation that 

did not compare as well was the top of cofferdam elevation. The 2001 survey 

measured the top of cofferdam at elevation 735, compared to the design drawing 

elevation 720. Limited research into the construction records found no evidence 

of the cofferdam being raised to such levels, but some documents indicated that 

the faces of the cofferdams were reinforced by construction crews due to concerns 

about their holding strength. It is also possible that the top of the upper cofferdam 

was raised during construction. Thalweg plots from previous surveys indicate 

that the cofferdam was completely buried at the time those surveys were 

conducted, but the top of the cofferdam is visible in the 2001 multibeam data. 

One explanation might be the consolidation of previously deposited sediment 

throughout the reach containing the cofferdam. Due to the compacted soil 

comprising the cofferdam, silt and clay sediment deposits upstream and 

downstream experienced greater consolidation over time than deposits along the 

top of the cofferdam. Figure 11 shows the top of the sediment at the intake 

towers around elevation 735 in 1950 following a density current event in 1949. It 

is assumed that after this period, additional sediment depth accumulated in this 

area, but no records reporting the extent of the deposition were located. The 1963 

longitudinal profile put the thalweg around elevation 735, but the exact locations 

of the 1963 cross sections were not documented, resulting in many unknowns in 

the dam area of the reservoir. Deep core bottom sampling would be needed to 

better support the theory of top of cofferdam elevation change due to sediment 

consolidation, but the 2001 survey shows the surrounding sediments compacted 
2001 Lake Mead Sedimentation Survey

60

upstream and downstream of the structure. Analysis of previous sampling and 

surveys, along with the mathematical results, led to the sediment consolidation 

conclusion in the lower reaches of the reservoir. 

Consolidation of Bottom Sediments 

Previous surveys of Lake Mead consisted of collected cross sections throughout 

the reservoir. These individual cross section locations were not available for this 

analysis. The only data available was what was presented in the two reports 

consisting of station distances between the cross sections varying from hundreds 

to thousands of feet. From the 1963 report, the Colorado River longitudinal plot 

showed a deep spike in the 1963 data between the dam face and the next collected 

cross section. The 1963 thalweg also plotted below the 1948 profile for about 

five miles upstream of the dam, indicating consolidation of the sediment surveyed 

in 1948. The 2001 data was collected by multibeam depth sounder and resulted in 

cross sections every two meters from the dam upstream for the first few miles and 

every 5 meters from that point upstream to just below the Pierce Ferry. The 2001 

survey collected detailed data along the original river channel alignment where 

the sediment deposition had occurred and that data was used to develop the 2001 

thalweg plot. 

The 2001 data measured the top of the deposited sediment from the dam face 

upstream to the toe of the cofferdam near elevation 702. This is similar to 

location of the spike in the 1963 thalweg data. In 2001 top of the cofferdam was 

measured at elevation 735 with the upstream toe of the cofferdam around 

elevation 719. Since cross sections from the previous surveys were not located 

along the crest of the cofferdam, the top elevation was not known except from 

design drawings labeling top of cofferdam at elevation 720. The Colorado River 

longitudinal plot, figure 23, shows that the 1948 survey was near elevation 735 at 

the face of the dam and the plot of the 1963 survey started near elevation 720, 

jumped to elevation 730, then sloped gradually upstream. The 2001 survey 

results show an elevation of 702 at the upstream face of Hoover Dam and a 17-

foot elevation difference between the downstream and upstream toes of the 

cofferdam. It is assumed that during initial filling a large load of sediment was 

deposited upstream of the cofferdam that consisted of sand, clay, and silt material. 

As the reservoir pool rose, the sand material was deposited further and further 

upstream of the cofferdam forming a sand/clay/silt deposition lens from the 

cofferdam upstream. Once the reservoir water level overtopped the cofferdam 

and became controlled by Hoover Dam, the cofferdam continued to act as a 

coarse sediment barrier, allowing only the fine silt/clay sediment mix to enter the 

zone between Hoover Dam and the cofferdam. If the initial top of the cofferdam 

was at elevation 720, then the upper portion of the reservoir was entering the 

Boulder Canyon and Virgin Basin portions of the reservoir at that elevation. 

Heavier sediments, such as the sands and gravels, would have mainly settled in 

this upper area of the reservoir. As explained in the density current studies, after 

initial filling, the sediments transported downstream were primarily the finer 

silt/clays that deposited upstream and downstream of the cofferdam. Over time, 
61

these fine sediment deposits consolidated and since the material between the two 

dams consisted mainly of the finer sediment with a relatively low initial density, 

more consolidation occurred there. 

The sampling of deposited sediments in reservoirs provides the most useful 

information on the density of deposits (Strand and Pemberton, 1982). The 2001 

survey conducted by the Sedimentation Group did not conduct a reservoir 

sediment bottom sampling program like the 1948 and 1963 surveys. The 

Woodhole USGS study conducted a sampling program in 2002, but the results 

were not available at the time of this analysis. There was a 1998 USGS sediment 

sampling program and the results of that study, along with the previous sampling 

results, were used to generate the conclusions for this analysis (Covay and Beck, 

2001). The 1998 sampling was only conducted at four sites from near the dam 

upstream to the confluence of the Overton Arm and Colorado River, but the 

results indicated that density currents are an ongoing process, transporting fine 

sediments from the upper end of the reservoir and depositing them throughout the 

reservoir towards the dam. The results show that even though the major source of 

sediment has been cut off due to closure of Glen Canyon Dam, there are still 

inflowing sediments that continue to deposit throughout Lake Mead. The 

collected samples were described as saturated, medium saturation, or minimal 

saturation and some were classified as silt core layers. The porosity of the cores 

was calculated relative to the length of the reservoir. Surface porosities near 0.8 

were computed for locations such as the confluence of Las Vegas Bay with the 

Colorado River. The sampled porosity at the Colorado River and Virgin River 

confluence was 0.95, meaning a great amount of space between the sediment 

particles were available for future consolidation. The higher sampled surface 

porosity indicated density currents were continuing to move the fine sediment 

from the inflowing drainage basins toward Hoover Dam. 

The longitudinal plot, figure 24, created for the 1948 study illustrates the initial 

deposition of the inflowing sediment. As the river enters the reservoir the 

velocity is reduced along with the transport capacity, causing the coarser sediment 

material to drop out and deposit in the upper delta area. These materials settle and 

sort themselves resulting in an initial high density formation in the upper delta. 

Future density change due to consolidation is minimal in the coarse deposits. The 

bulk of the finer materials are carried downstream where it begins to settle. In 

some cases, the reservoir density currents carry the finer material along the 

original river channel alignment all of the way to the dam. As described in the 

1948 report, during initial filling when the diversion tunnels where still open, the 

density currents carried a portion of this fine material downstream of Hoover 

Dam. Since the permanent closure of the diversion tunnels located upstream of 

the cofferdam at the original level of the Colorado River, the majority of this fine 

material now eventually settles on the reservoir bottom. Over time this material, 

whose top of elevation was measured by high frequency depth sounders, begins a 

natural compression, filling the previous voids between the sediment particles. 
2001 Lake Mead Sedimentation Survey

62

The density of the deposited sediment material stored in the reservoir increases 

over time, changing the current and future capacity of the reservoir. There are 

basic factors that influence the density of sediment deposits in a reservoir, such as 

the manner in which the reservoir is operated. Lake Mead’s water storage is 

directly affected by the upstream drainage runoff. Even before the creation of 

Lake Powell, it took years to fill Lake Mead during normal water-years while 

maintaining obligated downstream annual releases. Once Lake Powell initially 

filled, the obligated compact annual releases from Glen Canyon Dam became 

almost nine million acre-feet during normal water years and these required 

releases only increase during high runoff years. Under these conditions, the 

reservoir operation runs in cycles. At times there will be several consecutive 

years of low reservoir content followed by operation near full capacity after years 

of above average runoff. These changes in reservoir level affect the location and 

average top elevation of the upstream delta, but the initial density of these 

deposits changes little over time since they consist of the coarser 

sand/gravel/cobble/boulder mix. The 2001 survey measured the most reservoir 

bottom change since the previous surveys in the basins more near the dam that 

have been submerged since initial filling. 

The inflowing sediment texture varies from large material to very fine. The fines 

have been found to enter the upper reach more than 100 miles upstream of Hoover 

Dam then the density currents push them downstream. The larger material drops 

initially in the upper delta and mostly remains in place until conditions change. 

Such as a drop in the reservoir level increasing the transport capacity in the upper 

reservoir, pushing eroded material further downstream until it enters the reservoir 

environment again. 

The upper delta has little consolidation since it consists of mainly coarser material 

that drops out as the river velocity slows due to the flow expansion entering the 

reservoir. The fine material eventually settles on the reservoir bottom throughout 

the reservoir and initially settles very loosely according to previous sediment 

sampling results. Over time this finer material consolidates in place and 

additional loosely compacted fine material settles on top. In many reservoirs, 

sediment deposits are subjected to considerable drawdown, exposing them for 

long periods of time. Exposed sediments can undergo a great amount of 

consolidation from drying out. This is an ongoing process in most reservoirs, but 

in Lake Mead the majority of the fine material typically settles in deeper portions 

of the reservoir that have not been exposed since initial filling. The accumulation 

of new sediment on top of previously deposited sediment changes the density of 

earlier deposits. This consolidation increases the average sediment density over 

the life of the reservoir and was measured by the 2001 survey. A method that 

takes into account many factors in determining the density of deposited sediment 

is demonstrated in Reclamation guidelines and was used to estimate the potential 

consolidation with the information available for this analysis (Sedimentation 

Group, 2006). Appendix IV has a more detailed summary of the reservoir 

sediment compaction analysis conducted using these guidelines. 
63

For this analysis, Lake Mead operation was classified as always submerging or 

nearly submerging the sediment with a big factor in the consolidation 

computations being the density of the initial sediment deposition. Including or 

excluding sand can also influence the results significantly. During the initial 

filling sand was deposited from the dam upstream, but since then, the analysis 

assumed the deposited material contained no sand. Results from previous 

sampling programs and profiles plotted in figure 24 indicate the surface density 

could be less than 30 lb/ft3

, but the thickness of the deposition to which that 

density applies is unknown. 

The following equations were used to show the effect of consolidation over time 

on Lake Mead. With more information, a better result could be obtained to more 

accurately resemble the 2001 survey results. More than 1,300 samples were 

statistically analyzed by Lara and Pemberton (1965) to determine the 

mathematical equations for density variation of the deposits (unit weight or 

specific weight) for each type of reservoir operation. Additional data on density 

of deposited material from numerous reservoir resurveys have supported the Lara 

and Pemberton equations. In determining the density of sediment deposits in 

reservoirs following a certain type of reservoir operation, Lara and Pemberton 

recognized that a portion of the sediment will deposit in the reservoir during each 

year of operation, and each year’s sediment deposit will have a different 

compaction time. Miller’s (1953) approximation of the integral for determining 

the average density of all sediment deposited over the entire period of operation 

was used for this analysis. 

There are many factors affecting the sediment deposits within Lake Mead and 

additional extensive studies could be conducted to better address many of them. 

Since the 2001 study was mainly concerned with current reservoir capacity and 

future rate of loss due to inflowing sediments, studying these factors was of 

interest, but was not required for development of the 2001 results and 

conclusions. In general, the specific weight is determined by the grain size and 

thickness of the deposit. The consolidation of the sediment deposition is a time 

dependent process that increases the specific weight. The deeper reservoir 

sediments consolidate due to the passage of time and additional sediment 

deposition on top. For the upper delta, the heavier and coarser sediment particles 

rest directly against one another when they are initially deposited. The void 

spaces between the coarse grains are large enough for water to flow through, 

allowing this heavier material to remain in place. If the upper reservoir carrying 

capacity increases due to reservoir drawdown followed by high inflows, a portion 

of the previously deposited materials are pushed further downstream. The 

silt/clay materials are carried further downstream and initially settle loosely with 

many voids that are initially filled with water. Over time and as additional layers 

of weighted sediment are deposited, these voids begin to collapse replacing the 

water with sediment material as they compress (Morris and Fang, 1997). This is 

the ongoing process occurring in Lake Mead and was measured during the 2001 
2001 Lake Mead Sedimentation Survey

64

survey, resulting in lower bottom elevations in some areas of the reservoir. Since 

closure of Glen Canyon Dam, the compaction still continues, but at a reduced rate 

due to the decreased sediment inflow. As the fine materials continue to be 

transported downstream to the dam by density currents, they will eventually 

deposit and compact over time. 

Compaction analysis 

The following calculations refer to Reclamation guideline, “Reservoir 

Sedimentation” (Strand and Pemberton, 1982) and Reclamation manual, Erosion 

and Sedimentation Manual (Sedimentation Group, 2006). 

Reservoir operation: Sediment always submerged or nearly submerged. 

Estimate the density of the sediment deposits. 

 W = Wcpc + Wmpm +Ws + ps 

 Where: 

 W = unit weight in pounds in cubic feet 

 pc, pm, ps = percentages of clay, silt, and sand, respectively, of the 

 incoming sediment 

 Wc, Wm, Ws = coefficients of clay, silt, and sand, respectively. Obtain 

from reference 

For a classified reservoir operation of 1 

Wc = 26 (initial weight in lb/ft3) 

Wm = 70 (initial weight in lb/ft3

) 

Ws = 97 (initial weight in lb/ft3

) 

From 1963 Lake Mead study, the reported sampling was 

Clay = 60% 

Silt = 28% 

Sand = 12% 

W = 26(.60) + 70 (.28) + 97 (.12) = 46.84 

In determining density of sediment deposits in reservoirs over time of reservoir 

operation, it is recognized that portions of the sediment will deposit over each 

operational year “T” and each year’s deposits will have a different compaction 

time. 
65

 WT = W1 + 0.4343K [ T / (T-1) (logeT)-1] 

 Where: 

 WT = average density after “T” years of reservoir operation 

 W1 = initial unit weight (density) as derived from first equation 

 K = constant based on type of reservoir operation and 

sediment size analysis as obtained from table for 

different reservoir operations

For reservoir operation number 1 

 K (sand) = 0 inch-pound 

 K (silt) = 5.7 inch-pound 

 K (clay) = 16 inch-pound 

 K = 16(0.60) + 5.7(.28) + (0)(.12) = 11.196 

For 66 years of Lake Mead operations since dam closure 

 W66 = 46.84 + 0.434 (11.196) [66 / (66-1) (4.19) -1] 

= 46.84 + (4.86) (3.25) 

= 62.63 lb/ft3

Assumed some sediment at dam occurred during construction and initial filling. 

Since 1963, 38 years of operation with sediments submerged. 

W38 = 46.84 +0.4343(11.196) [ 38 / (38-1) (3.64)-1] 

 = 46.84 + 4.86(2.74) 

= 60.15 lb/ft3

After 13 years of operations (1935 – 1948): 

W13 = 46.84 + 0.4343 (11.196) [13 / (13 – 1) (loge (12)-1] 

 = 53.6 

From 1948 – 64: 

W16 = 53/6 + 0.4343(11.196) [16 / (16-1)(loge16)-1]

 =62.2 
2001 Lake Mead Sedimentation Survey

66

After 37 years (1964-2001) 

W37 = 62 + (0.4343)(11.196) [(37 / (37-1) loge(37) - 1]

 = 75 

From field survey results 

1948 survey measured around 80 feet of sediment deposition near the dam. 

1963 survey measured around 75 feet of sediment deposition near the dam. 

For 1963: (53.6/62.2)(80 feet) = 69 ft 

For 2001: (62/75)(75 feet) = 62 feet 

From equations: 

 69 ft – 62 ft = 7 feet of consolidation 

The 2001 survey analysis computed about 10 feet of consolidation. The 

calculations made several assumptions and many factors have changed in Lake 

Mead since initial filling. Such as the 1963 closure of Glen Canyon Dam cutting 

off the primary source of sediment inflow. The calculations considered sand in 

the initial sediment source, but since initial reservoir filling, the material in the 

lower basins mainly consists of a clay/silt mix. Under current conditions, the 

amount of sand flowing into the lower basins of the reservoir could be considered 

zero. As seen on figure 24 and in the 1998 sediment sampling results, the top 

layer of the sediment is initially deposited in a loosely compacted state that 

increases in density as new layers of sediment are deposited on top. The above 

example calculations demonstrate the ongoing consolidation process and how all 

the survey results could be used to better define the current condition of Lake 

Mead. 
67

Summary of Sedimentation Group’s 

Processing 

By agreement, the final x,y,z formatted data was forwarded to the LCR for GIS 

analysis in July 2001 upon completion of the multibeam data processing by the 

Sedimentation Group. The Sedimentation Group and LCR remained in 

communication during the analysis period and the first extensive data set was 

delivered to Denver in March 2002. As previously described, the GIS analysis 

generated the original and 2001 map boundary data using 10-meter DEM data 

from the USGS quadrangle maps and 2001 multibeam data. The LCR GIS 

analysis utilized the DEM to redevelop the original contours and resulting surface 

areas in metric increments. The resulting surface area values were imported into 

spreadsheets in square meters and converted to acres to match the English units in 

Table 3-3 of the 1963 report. The LCR GIS original surface area computations at 

10-foot increments were within two percent or less of the original published 

surface areas. This was considered a very close match, but for the large volume 

of Lake Mead, a one percent difference translates to more than 300,000 acre-feet 

at full capacity. 

Due to the lack of original and 2001 data, the LCR GIS analysis assumed the 

original volume from Pierce Basin upstream had been totally lost due to sediment 

deposition. From previously collected cross section data and study results, the 

Sedimentation Group’s analysis showed that the reservoir area from Pierce Basin 

upstream is largely lost due to sediment deposition, but there is available reservoir 

capacity remaining that was accounted for in their analysis. The original volume 

from Pierce Basin upstream was over 1,400,000 acre-feet prior to Hoover Dam 

closure, but soon after closure, sediment deposition began to fill a large portion of 

this area. The 1948 study measured 725,000 acre-feet and the 1963 study 

measured 921,000 acre-feet of sediment in this portion of the reservoir, table 6. 

As discovered in these previous studies, the surface areas in the very upper 

elevation zones (elevation 1,200 and above) were not drastically affected by 

sediment deposition. This is illustrated on the longitudinal plot of the Colorado 

River on figure 23, along with the cross sections developed by the LCR analysis, 

figures 25 and 26. Appendix III contains plots of additional cross sections located 

throughout the reservoir. Due to the lack of original and 2001 data, none of these 

plotted cross sections were located from Pierce Basin upstream. The 1963 report 

has several cross section plots located in this portion of the reservoir that compare 

the original, 1948, and 1963 survey results. At several cross sections the 1963 

sediment surface elevation plotted below the 1948 results. The 1963 survey was 

conducted with a drawn down reservoir, meaning a portion of the previous 

sediment deposits in the upper reservoir had been eroded since the 1948 survey. 

In most cases the top of the sediment deposition for both surveys plotted below 

elevation 1,200. This further signifies little to no change from the original 

capacity in these upper elevation zones of the reservoir. 
2001 Lake Mead Sedimentation Survey

68

The Sedimentation Group computed the 2001 reservoir capacity and resulting 

sediment deposition for the upper reservoir area using the original hard copy map 

contours, 2001 LiDAR, and the Biological cross section data for the areas from 

Pierce Basin upstream. Even though the majority of this volume area is lost due 

to sediment deposition, a 40 mile reach of surface area remains in the upper 

elevation zones and was included in the 2001 final surface area and capacity 

computations. The 2001 survey measured around 337,500 acre-feet of available 

volume from Pierce Basin upstream. Since the 2001 survey, the reservoir water 

content has dramatically decreased due to the ongoing draught within the 

Colorado River drainage basin. The pool elevation has dropped to Gregg Basin 

and continues to move further downstream. The lower reservoir levels have 

subjected the upper basin sediment delta to alteration by the Colorado River. 

Since the 2001 survey, a portion of the previously deposited delta sediments have 

been eroded and transported downstream toward the dam, increasing storage 

capacity in these upper basins. In the future, these areas of increased volume will 

refill with sediment as they become inundated by the reservoir again. This 

ongoing cyclical process will continue throughout the varying operational 

scenarios of Lake Mead. As illustrated by the Sedimentation Group’s 2001 

analysis, a certain zone of reservoir capacity will exists in the upper basin at all 

reservoir operational levels. 

Section G-G'

850

900

950

1000

1050

1100

200.00 400.00 600.00 800.00 1000.00 1200.00 1400.00 1600.00

Distance In Feet

Elevation in Feet

1935 Elevation 1948-49 1963-64 2001 Elevation

Figure 25 - Gregg Basin section G-G 
69

Section H-H'

800

820

840

860

880

900

920

940

960

980

1000

4000 5000 6000 7000 8000 9000 10000

Distance in Feet

Elevation in Feet

1935 Elevations 1948-49 1963-64 2001 Elevations

Figure 26 - Gregg Basin section H-H 

The reconnaissance method of collection and analysis was applied to the 2001 

Lake Mead study by the Sedimentation Group (Ferrari, 2006). When compared to 

the LCR approach, the Sedimentation Group’s analysis resulted in only a slight 

difference in the sediment deposition values for maps 1 through 41 (Appendix V). 

The biggest difference was the analysis method used in the upper reservoir area, 

from Pierce Basin upstream, and in the upper reach of the Overton Arm. The 

Sedimentation Group analyzed each individual map over the total reservoir, 

computing the capacity and sediment deposition for the total reservoir. The only 

means to truly measure the current volume of the reservoir would be through a 

combination of detailed above and below water surveys. Detailed surveys for an 

entire reservoir the size of Lake Mead would be cost prohibitive. Utilization of 

reconnaissance techniques and methods provided the tools necessary for 

collection and analysis of the 2001 Lake Mead survey data in a cost effective and 

accurate manner. The reconnaissance method was similar to the previous 

sediment surveys of Lake Mead where these methods were based on changes 

from the original topography. 

Using ARC GIS tools with the TIN’s LCR developed for the individual maps, 

contours and surface areas were developed at 10-foot intervals to match the 

original elevation increments. During the processing it was determined that the 

TIN’s, contours, and resulting surface areas developed from the USGS DEM’s 

did not provide sufficient detail at some lower elevation contours and in small 

coves to match the original map details and resulting surface areas. The lack of 

detail was a concern initially because the 2001 collected data was merged with the 
2001 Lake Mead Sedimentation Survey

70

original USGS DEM data to develop the updated contours and surface areas for 

the available maps. However, the 2001 data found that most of these smaller 

areas had silted in, easing the initial concerns. The Sedimentation Group’s 

analysis treated the original reported surface areas (listed in the 1963 report by 

map, at 10-foot contour intervals) as the base surface areas and focused their 

analysis on identifying changes from these values. The 1948 and 1963 studies 

used the same approach, allowing the 2001 Sedimentation Group results to better 

determine changes over time due to sedimentation deposition. Even though the 

2001 data was of much greater detail in the areas of sediment deposition than the 

previous surveys, the Sedimentation Group’s approach allowed for confident 

comparisons with previous results. 

The 2001 LiDAR data merged with the 2001 depth data and previously collected 

biological cross sections provided adequate detail for estimating changes from the 

original topography on maps 40, 42, and 43 in the upper reservoir. The 2001 

analysis computed surface areas for these maps using the LiDAR data (with 

elevations adjusted to match the Lake Mead vertical datum) along with the other 

merged data sets. The 2001 results showed that much of the upper reservoir area 

was lost due to sediment deposition, but just as the 1948 and 1963 surveys 

revealed, reaches of available reservoir capacity still remain, table 6 and table 7. 

For most reservoir maps, the 2001 multibeam survey data provided adequate 

detail for GIS development of the entire 10-foot contour elevation within the map 

boundary. The 2001 GIS measured surface areas were used for the analysis on 

those maps. Using the GIS computed surface areas accounted for sediment 

deposition that may have occurred along the canyon walls, figure 27. When the 

2001 data indicated little to no change due to sediment deposition, the original 

surface area was used for the 10-foot contour interval being examined on that 

map. The smaller river channels covered by the Las Vegas Wash and Overton 

Arm maps were analyzed using the 2001 survey data collected primarily along the 

original thalweg. No change due to sediment deposition was assumed in the 

remaining surface areas of the Overton and Las Vegas maps. This assumption 

was supported by the 2001 survey and by previous cross section surveys of Lake 

Mead measuring the change due to sedimentation primarily in the deeper original 

river channel portion of the maps. Using ARC GIS tools, the 2001 contours in the 

river channel zone were digitized to compute the updated surface areas reported at 

each 10-foot elevation increment. Table 3 presents the results of the 2001 

Sedimentation Group’s analysis. The original surface areas listed in table 1 

provided the basis for table 3. Surface area values by map and elevation were 

changed as the 2001 computations indicated. Appendix V contains a map by map 

summary of results from the analysis conducted by the Sedimentation Group.
71

Figure 27 - Multibeam data of Navajo Canyon on Lake Powell showing deposition along toe of vertical wa
2001 Lake Mead Sedimentation Survey

72
73

10-Foot contour Areas in Acres ####

####

Sheet No Elevation (feet) 

660 670 680 690 700 710 720 730 740 750 760 770 

1,2,3

4 0.00 0.00 0.00 0.00 0.00 0.00 0.00 76.84 269.97 400.65 457.40 506.30 5

5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 329.28 551.65 754.17 813.95 858.84 9

6,7 0.00 0.00 0.00 0.00 0.00 0.00 0.00 46.29 987.44 1,873.93 2,355.17 2,662.51 2,8

8 0.00 0.00 0.00 0.02 0.47 3.90 53.69 897.15 1,339.46 1,621.83 1,677.21 1,734.17 1,7

9 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.03 13.16 128.95 607.48 734.58 7

10

11,12 0.00 0.00 0.00 0.00 0.00 0.03 0.16 0.39 0.67 1.21 73.08 410.62 1,2

1415161718 19 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.40 1.32 1

20,21

2223242526 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

27 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 283031323334 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 35 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 36 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 37 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 38 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3940 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 41 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 42 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 43444546474849505152

Total 0.00 0.00 0.00 0.02 0.47 3.94 53.87 1,349.98 3,162.35 4,780.75 5,984.68 6,908.34 8,2

Table 3 - 2001 Lake Mead surface areas (1 of 4). 
2001 Lake Mead Sedimentation Survey

74

 10-Foot contour Areas in Acres ####.

####.

Sheet No Elevation (feet) 

810 820 830 840 850 860 870 880 890 900 910 920 

1,2,3

4 665.60 720.00 771.00 820.10 871.60 934.20 1,011.50 1,102.60 1,205.30 1,312.70 1,444.10 1,580.10 1,75 1,288.78 1,422.75 1,577.07 1,719.89 1,862.11 2,006.37 2,197.14 2,318.83 2,503.16 2,710.80 2,940.59 3,099.03 3,2

6,7 3,273.92 3,407.43 3,541.45 3,698.77 3,858.52 4,034.51 4,213.40 4,433.06 4,608.68 4,727.52 4,918.80 5,094.28 5,2

8 1,965.81 2,031.74 2,089.03 2,147.32 2,211.16 2,279.50 2,341.28 2,403.01 2,455.15 2,512.82 2,587.73 2,643.16 2,69 870.59 918.26 956.16 993.69 1,045.35 1,098.46 1,151.75 1,206.41 1,261.06 1,318.28 1,385.41 1,455.04 1,5

10

11,12 1,650.14 1,728.29 1,809.59 1,873.10 1,946.31 2,021.43 2,088.52 2,163.52 2,253.84 2,338.08 2,456.98 2,533.51 2,6

1415161718 319.11 499.46 635.73 798.29 901.72 998.58 1,066.86 1,149.05 1,190.72 1,225.00 1,313.95 1,360.66 1,419 3,535.90 4,034.76 4,380.65 4,637.82 5,025.43 5,301.62 5,449.20 5,758.26 5,983.84 6,203.50 6,445.21 6,688.94 6,9

20,21

22232425 2.32 60.10 128.20 188.60 319.20 426 817.64 1,008.90 1,069.00 1,167.20 1,272.80 1,422.60 1,620.80 1,771.95 1,912.45 2,057.28 2,228.68 2,381.62 2,5

27 846.99 1,214.39 1,373.38 1,516.04 1,804.83 1,998.98 2,159.17 2,327.55 2,517.89 2,695.22 2,938.69 3,319.14 3,7

283031323334 0.08 101.14 326.70 371.30 396.61 418.52 453.20 478.99 510.19 544.53 596.56 643.33 7

35 0.00 0.03 193.19 812.56 1,342.20 1,607.14 1,734.94 1,873.57 2,036.65 2,206.25 2,372.14 2,513.49 2,6

36 0.00 0.00 0.70 1.21 1.81 173.29 386.12 454.84 498.56 509.53 529.81 578.21 6

37 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1.87 3.53 5.51 19.23 1

38 0.00 0.00 0.00 0.00 0.00 0.60 3.08 59.24 191.93 659.20 1,211.92 1,693.24 1,93940 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 41 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 42 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 43 0.00 0.00 0.00 0.00 0.00 44 0.00 0.00 0.00 4546 474849505152

Total 15,234.55 17,087.14 18,723.65 20,557.29 22,540.45 24,295.79 25,876.97 27,503.20 29,191.39 31,152.43 33,564.68 35,922.18 38,2

Table 3 -2001 Lake Mead surface areas (2 of 4). 
75

####.## 

####.## 

Sheet No Elevation (feet)

960 970 980 990 1000 1010 1020 1030 1040 1050 1060 1070 

1,2,3 4.50 24.30 46.40 76.40 109.20 

4 2,142.00 2,296.40 2,475.70 2,666.30 2,869.00 3,067.50 3,286.40 3,519.95 3,739.29 3,978.76 4,221.40 4,434.55 5 3,828.17 4,014.64 4,168.55 4,343.44 4,484.45 4,714.97 4,876.11 5,014.37 5,148.99 5,290.08 5,419.92 5,510.58 

6,7 5,817.96 5,989.21 6,157.86 6,293.96 6,435.16 6,603.63 6,769.31 6,940.60 7,123.96 7,286.93 7,476.59 7,659.63 

8 2,879.64 2,936.30 2,999.47 3,061.14 3,144.25 3,208.44 3,263.76 3,322.21 3,362.06 3,416.20 3,483.80 3,550.74 9 1,710.65 1,781.38 1,850.18 1,906.19 1,965.44 2,047.38 2,126.50 2,196.21 2,260.09 2,331.74 2,410.99 2,488.68 

10 

11,12 2,870.26 2,958.63 3,078.72 3,182.09 3,278.30 3,379.79 3,470.00 3,565.06 3,667.21 3,767.17 3,884.94 3,994.71 

141516 0.50 17 18 1,665.87 1,731.99 1,797.87 1,874.74 1,946.04 2,040.84 2,114.78 2,202.87 2,283.71 2,368.15 2,442.06 2,507.12 19 7,625.83 7,895.94 8,156.88 8,420.82 8,734.72 9,095.69 9,449.17 9,803.25 10,155.49 10,469.13 10,732.07 11,024.89 

20,21 1.45 25.40 49.88 87.21 119.38 162.56 215.53 270.30 352.61 429.72 502.59 

2223 66.80 541.20 24 198.65 720.60 1,229.70 1,756.60 2,408.30 2,963.30 3,695.00 4,518.20 5,444.82 5,993.35 25 1,409.70 1,775.30 2,157.99 2,349.73 2,570.31 2,772.34 2,961.07 3,179.57 3,403.60 3,644.20 3,918.79 4,185.91 26 2,995.05 3,156.53 3,320.02 3,489.59 3,655.31 3,842.08 4,021.64 4,234.23 4,449.59 4,640.20 4,823.00 5,030.26 27 4,417.29 4,602.62 4,786.35 4,979.05 5,173.67 5,371.07 5,556.68 5,789.77 5,989.44 6,166.09 6,350.05 6,558.83 28 2.42 4.42 6.93 12.51 17.20 22.74 30.87 37.85 50.35 65.88 83.60 303132 0.00 3334 872.27 937.68 987.36 1,045.85 1,111.17 1,187.05 1,253.00 1,330.22 1,404.44 1,484.37 1,578.60 1,666.37 35 3,199.49 3,368.07 3,564.56 3,789.87 4,013.26 4,248.20 4,368.11 4,582.97 4,765.20 4,985.08 5,208.41 5,456.20 36 714.66 729.93 760.99 816.67 830.89 899.44 932.06 975.87 1,017.69 1,060.91 1,104.03 1,137.98 37 1,052.45 1,316.80 1,598.15 1,929.98 2,145.52 2,314.36 2,608.28 2,772.24 2,920.88 3,087.23 3,231.03 3,388.31 

38 2,259.66 2,351.30 2,435.74 2,590.77 2,687.41 2,789.50 2,882.70 2,980.04 3,108.18 3,223.87 3,373.38 3,484.70 

3940 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

41 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 6.76 40.26 92.04 136.92 

42 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 43 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 44 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 45 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 46 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 47 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 48 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 49 0.00 0.00 0.00 0.00 505152

Total 45,460.95 47,846.59 50,524.86 53,517.60 56,374.32 59,475.46 62,533.17 65,623.63 68,834.02 72,207.93 75,834.72 79,446.82 

10-Foot contour Areas in Acres

Table 3 - 2001 Lake Mead surface areas (3 of 4)
2001 Lake Mead Sedimentation Survey

76

 10-Foot contour Areas in Acres ####.## 

####.## 

Sheet No Elevation (feet)

1100 1110 1120 1130 1140 1150 1160 1170 1180 1190 1200 1210 

1,2,3 254.20 333.00 431.00 520.10 617.00 699.80 787.70 881.60 989.20 1,116.00 1,298.90 1,494.40 

4 5,187.61 5,505.20 5,834.84 6,154.83 6,352.18 6,656.44 6,866.41 7,255.04 7,536.44 7,794.41 8,072.43 8,404.44 5 5,901.89 6,021.44 6,153.35 6,295.57 6,428.69 6,572.55 6,724.99 6,879.33 7,046.18 7,227.96 7,403.83 7,617.46 

6,7 8,234.25 8,384.30 8,549.14 8,714.64 8,890.94 9,051.65 9,249.34 9,403.96 9,591.52 9,788.03 9,965.52 10,177.46 

8 3,712.58 3,789.67 3,854.53 3,918.67 3,968.08 4,037.77 4,100.81 4,163.85 4,227.09 4,295.15 4,356.23 4,413.15 9 2,700.62 2,804.81 2,902.72 2,972.54 3,047.79 3,124.29 3,197.49 3,276.61 3,352.59 3,429.93 3,502.23 3,596.92 

10 5.24 7.39 9.59 13.57 16.39 19.61 24.95 32.11 39.74 47.56 54.63 65.87 

11,12 4,332.81 4,463.51 4,561.10 4,661.28 4,764.58 4,863.69 4,976.20 5,060.50 5,174.32 5,302.95 5,433.08 5,570.32 

14 15 16 11.85 51.33 109.32 168.77 234.05 283.29 373.42 447.96 536.40 630.08 738.54 860.08 17 12.00 38.10 73.20 117.10 159.70 210.45 281.44 378.74 503.18 626.53 783.76 903.83 18 2,776.78 2,868.58 2,959.18 3,030.15 3,094.66 3,161.92 3,255.87 3,321.25 3,402.83 3,471.79 3,557.72 3,645.39 19 11,844.38 12,139.95 12,423.55 12,716.82 13,058.49 13,453.99 13,873.64 14,220.79 14,592.83 14,908.13 15,231.37 15,578.01 

20,21 748.19 811.45 877.79 951.29 1,046.21 1,153.23 1,308.33 1,478.00 1,657.03 1,798.93 1,945.96 2,192.31 

22 0.00 0.00 0.00 345.10 814.10 1,392.20 1,841.70 

23 1,439.30 1,983.40 2,462.10 2,834.60 3,292.00 3,790.80 4,226.90 4,844.90 5,834.75 6,315.91 6,723.40 7,114.30 24 7,252.96 7,566.60 7,885.97 8,220.90 8,524.35 8,864.49 9,161.94 9,533.25 9,842.54 10,211.79 10,509.61 10,861.42 25 4,951.04 5,240.86 5,466.76 5,734.86 5,972.36 6,234.97 6,490.34 6,743.52 6,992.47 7,239.45 7,470.78 7,735.76 26 5,560.53 5,754.98 5,913.35 6,068.29 6,215.72 6,379.44 6,546.21 6,703.58 6,855.28 7,015.10 7,159.21 7,323.34 27 7,265.14 7,472.58 7,667.74 7,890.85 8,097.95 8,320.98 8,550.27 8,781.12 9,031.87 9,333.50 9,598.33 9,972.77 28 149.24 188.35 215.87 248.09 280.73 344.33 386.83 442.15 494.78 549.93 611.25 668.95 30 0.00 0.00 0.00 0.00 31 0.00 0.00 0.00 51.50 124.30 227.20 518.90 

32 13.70 79.79 131.08 208.42 264.60 402.00 610.50 705.00 886.67 934.26 1,021.07 1,130.60 

33 21.37 53.61 91.26 151.90 204.27 275.40 373.31 468.42 554.03 652.61 750.52 852.99 34 1,959.73 2,092.16 2,186.27 2,271.48 2,345.75 2,450.14 2,543.63 2,631.18 2,704.71 2,796.43 2,884.72 2,992.32 35 6,140.54 6,373.59 6,580.00 6,831.93 7,043.52 7,277.95 7,482.72 7,660.84 7,875.84 8,083.62 8,305.19 8,505.38 36 1,281.18 1,353.77 1,380.53 1,446.38 1,467.87 1,552.06 1,593.39 1,657.41 1,707.50 1,812.77 1,866.68 1,993.61 37 3,845.37 4,005.74 4,162.30 4,334.36 4,487.78 4,655.25 4,832.41 4,970.05 5,107.24 5,264.57 5,424.23 5,594.30 38 3,876.22 4,017.82 4,125.15 4,243.11 4,347.40 4,481.33 4,594.49 4,689.27 4,797.82 4,877.64 4,991.33 5,104.99 39 0.00 30.50 

40 95.45 209.21 471.25 606.10 1,331.89 2,459.30 2,983.40 3,383.60 3,541.52 3,787.59 3,939.46 4,101.59 

41 239.83 248.89 254.91 263.48 269.21 278.76 285.17 297.12 305.10 326.60 340.99 375.86 42 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 646.40 920.07 989.07 1,057.42 43 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2,599.00 4,502.36 4,693.49 44 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 229.00 374.00 453.70 1,180.99 45 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 67.00 363.00 446.00 1,013.55 46 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 64.00 154.00 302.82 320.75 47 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 199.00 451.29 480.41 48 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 66.00 350.03 374.27 49 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 208.00 398.30 431.49 50 0.00 0.00 0.00 0.00 79.13 94.22 109.31 127.90 5152

Total 89,814.00 93,860.08 97,733.85 101,590.08 105,824.16 111,055.88 115,682.10 120,311.15 126,663.60 135,554.91 143,563.25 150,919.19 

Table 3 - 2001 Lake Mead surface areas (4 of 4)
77

Reservoir Area and Capacity 

2001 Topography Development 

As described in the LCR analysis section, TIN’s along with resulting 

computations were developed for the areas of Lake Mead that had both original 

and 2001 data sets. The LCR analysis was completed by map area boundaries 

using the available USGS original DEM values and patching in the 2001 survey 

data where it overlapped. For this report, no final topographic map products are 

presented. The LCR developed digital data is available online (Twitchel, 2003). 

Development of the Contour Areas and Reservoir 

Volume 

The Sedimentation Group computes storage-elevation relationships, based on TIN 

generated surface areas, using the area and capacity computer program ACAP 

(Bureau of Reclamation, 1985). The surface area information, as described 

previously, was used to establish control parameters for computing the updated 

reservoir capacity. Since the 2001 study had no above-water data, the original or 

previously measured surface areas above a certain elevation were used to 

complete the area and capacity tables. Due to the lack of updated above-water 

data for Lake Mead, this study assumed no change since the 1963 computations 

for the highest elevation upstream reaches unless available information indicated 

a change had occurred. The upper Colorado River reach of the reservoir above 

Pierce Basin was the only reach that had additional data to consider. This 

included the 2001 LiDAR and Biological surveyed cross section data. This is also 

the reach of the reservoir where sediment deposition is a major factor in 

computing the overall reservoir capacity loss. 

The ACAP program computes the area and capacity at designated elevation 

increments of 0.01- to 1.0-foot by linear interpolation between the given contour 

surface areas. The program begins by testing the initial capacity equation over 

successive intervals to ensure that the equation fits within an allowable error limit. 

The capacity equation is then used over the full range of intervals fitting within 

this allowable error limit. For the first interval at which the initial allowable error 

limit is exceeded, a new capacity equation (integrated from a basic area curve 

over that interval) is utilized until it exceeds the error limit. Thus, the capacity 

curve is defined by a series of curves, each fitting a certain region of data. By 

differentiating the capacity equations, which are of second order polynomial form, 

the final area equations are derived: 
2001 Lake Mead Sedimentation Survey 

78

y = a1 + a2x + a3x

2

where: y = capacity 

x = elevation above a reference base 

a1 = intercept 

a2 and a3 = coefficients 

For Lake Mead, surface area data was computed at 10-foot elevation increments 

for the original and 2001 survey results. Results of the 2001 ACAP reservoir area 

and capacity computations were compared to the original surface areas and 

recomputed ACAP original capacities for estimating the sediment deposition in 

the different reservoir elevation zones, tables 4 and tables 5. A separate set of 

area and capacity tables can be published for the 0.01, 0.1 and 1-foot elevation 

increments. In this report, the 2001 area and capacity table is presented at 0.1-

foot elevation increments in Appendix VI. Descriptions of the computations and 

output coefficients from the ACAP program are included with these tables. 

2001 Reservoir Sediment Analyses 

Results of the 2001 Lake Mead area and capacity computations are listed in table 

4 and in columns 8 and 9 of table 5. Columns 2 and 3 of table 5 list the original 

area and capacity values and the remaining columns list the values of the 1948 

and 1963 surveys and the comparisons between all of the measured values. 

Column 10 lists the capacity differences between the original and 1963 survey 

results and column 11 lists the original and 2001 survey result differences due to 

sediment deposition. Column 12 lists the differences between the 1963 and 2001 

surveys showing measured differences between the surveys with the consolidation 

of the previous sediments occurring in the lower reaches starting at elevation 700 

and peaking near elevation 1,125 where the measured reservoir volume increased 

by 421,680 acre-feet since 1963. Figure 28 is a plot of the Lake Mead surface 

area and capacity values for all surveys and illustrates the differences that have 

occurred over the years. 

The estimated 100-year sediment accumulation for Lake Mead was 1.25 percent 

or around 3,710,000 acre-feet. This corresponds to an annual loss of 37,100 acrefeet. It is unknown if this 100-year estimate considered additional reservoir 

development upstream of Lake Mead. Table 4 shows that the 2001 survey 

measured an average annual loss of 36,024 acre-feet since closure of Hoover Dam 

in 1935. This estimate was developed for the first 66.7 years of Lake Mead 

operation with only 29.7 of those years before development of Lake Powell. The 

significantly lower average annual loss measured by the 2001 survey, compared 

to the 1963 survey result of 88,280 acre-feet, was attributed to the closure of Glen 

Canyon Dam and the compaction of the previously deposited sediments. Since 
79

closure of Glen Canyon Dam and trapping of sediments within Lake Powell, the 

average sediment inflow is estimated to be less than 10,000 acre-feet per year. 

Future surveys will be needed to obtain a better estimate of the current sediment 

inflow, but if an annual 10,000 acre-feet were projected for the next 33.3 years; 

the annual projected sediment inflow would be around 27,000 acre-feet for the 

first 100 years of operation. 

Table 6 consists of eight pages that provide a breakdown of the computed 

capacity and sediment deposition by basin, elevation, and survey year. Page eight 

of this table provides the total capacity information for all the basins that make up 

Lake Mead. The 1963-2001 computed sediment volume shows the change that 

occurred due to compaction of sediment and the significant trapping of sediments 

within Lake Powell. The table indicates that the maximum change occurred at 

elevation 1,130 and the gain in capacity was 421,480 acre-feet. The Colorado 

River thalweg plot in figure 23 shows the change that has occurred between 

surveys. As seen from the plot, the elevation change due to compaction between 

1963 and 2001 occurred from Virgin Canyon Basin downstream to Hoover Dam. 

Even though the table shows an increase in capacity up to elevation 1,230, figure 

23 shows the upstream sediment delta growing as the delta face progresses further 

downstream toward the dam. The breakdown of the basins within table 6 shows 

that between 1963 and 2001 the basins of Grand Bay, Pierce, and Lower Granite 

Gorge have decreased in capacity due to sediment deposition. During this period 

the capacity decrease within these basins was around 267,300 acre-feet or around 

7,200 acre-feet per year at elevation 1,230. These computations are only for the 

Colorado River and do not take into account the Overton and Las Vegas Wash 

drainage areas or the fine sediments that have been transported towards the dam 

by density currents. Considering all of the factors not accounted for, an annual 

Lake Mead sediment inflow of less than 10,000 acre-feet, since closure of Glen 

Canyon Dam, was estimated for this study. 

Table 7 contains computed surface areas listed by elevation increments and date 

of survey. The 1948-1935 and 1963-1948 data comparisons show surface area 

losses throughout all elevation zones from 1,230 and below. The 1948-1935 

column (table 7) does show a surface area increase at elevation 1,230 that appears 

to be due to rounding of the surface area values for the 1948 survey. Elevations 

1170 through 1220 of the 1963-1948 comparison also identify a gain in surface 

area between the two surveys. The 1963 survey was conducted at a much lower 

reservoir elevation, meaning some of the previously deposited sediment in the 

upper basins on the Colorado River was eroded and transported downstream to 

the lower elevation zones of the reservoir between 1948 and 1963. The 2001 

survey was conducted when the reservoir was at a higher content than in 1963 and 

the 2001-1963 analysis calculated a loss of surface area due to the upstream 

growth of the sediment delta above elevation 1,130. However, the 1963 and 2001 

data indicate minimal loss due to sediment delta growth in the extreme upper 

elevations above 1,200. These upper elevation zones may have actually increased 

in surface area due to shoreline erosion that has occurred to different extents 
2001 Lake Mead Sedimentation Survey 

80

throughout the reservoir. The only means of measuring the current surface area of 

the upper elevation zone would be an aerial survey covering the entire reservoir. 

Consolidation of sediments is an ongoing process in all reservoirs. Due to its 

relatively large size, Lake Mead provided a unique opportunity to observe and 

measure the impact of sediment consolidation. The current and future geometry 

of many other reservoirs has been altered by upstream development, but the 

impact of removing a substantial portion of inflowing sediment for 40 years is 

measured on a much larger scale at Lake Mead. Future surveys should focus 

more on better measurement of the current sediment inflow and the redistribution 

of the previous sediment deposits. Given the current drought situation, the 

reservoir has dropped over 80 feet in elevation since the 2001 survey. This drop 

has allowed river inflows to erode a portion of the previous sediment deposits and 

carry them into the lower elevation portions of the reservoir where they are 

redeposited. Future surveys would be necessary to measure the redistribution and 

current sediment deposition rate. The 2001 survey utilized state of the art 

technology for measuring the underwater sediment deposition. Future technology 

may provide additional tools for more detailed measurements in a costly matter. 

With the current reservoir drawn down so low, above water data collection 

options should be explored. One option that should be considered is satellite 

imagery of the reservoir. Satellite images at different reservoir levels could be 

used to develop accurate water surface contours in the areas where little change 

has occurred due to sediment deposition. Of course a full detailed aerial survey 

would provide the most accurate and complete data set. 
81

1. 2. Colorado River 3. STATE Arizona - Nevada

4. 5. Boulder City 6. COUNTY Clark-Mohave

7. ° 00 ' 58 " ° 44 ' 13 " 8. 1 9. SPILLWAY CREST EL 2

10. 11. 12. GROSS STORAGE 15

CAPACITY, AC-FT

a. 3

b.

c.

d. 16

e.

f.

g.

17. LENGTH OF RESERVOIR 4

18. TOTAL DRAINAGE AREA 5 22. 6

19. NET SEDIMENT CONTRIBUTING AREA 5 23. MEAN ANNUAL RUNOFF 7

20. LENGTH MILES AVG. WIDTH MILES 24. MEAN ANNUAL RUNOFF 8

21. 25. °F °F

26. DATE OF 27. 28. 29. 30. 31. C/

26. DATE OF 35. 36

26. DATE OF 37. 38.

26. DATE OF 39.AVG. DRY WT. 40. SED. DEP. TONS/MI.2

-YR 41. STORAGE LOSS, PCT. 42 SEDIMENT 

(#/FT3

) b. TOTAL b. TOTAL TO INFLOW, PPM

TO DATE DATE a. PER. b. TOT.

43.

ACRE-FEET

INCHES

9/01 12

Contour (D) 10-ft 162,677

714 0.27

a.

879

7,700

8,460

0.84

8.1

8,460

7,760

14

15

175,362,000

4.1

88,280

36,024 0.34

14 97,429 0.92

a. MEAN ANN. b. TOTAL

175,362,000

1,334,780 14 97,429 1,334,780 0.58

162,608 10

31,047,000

162,548 12

115

PERCENT OF TOTAL SEDIMENT LOCATED WITHIN DEPTH DESIGNATION

120-

125

115-

120

105-

105 111

E 16 29.7 10/14/64 Contour (D)

A 9/30/48

INACTIVE

FLOOD CONTROL

POWER

JOINT USE

CONSERVATION

114

Bureau of Reclamation

LONG

SURCHARGE

ELEVATION

TOP OF POOL

36

OWNER

SEC

LAT

105,550 SQUARE MILES 1.22

AVG. WIDTH OF RESERVOIR

INCHES

1.65

171,700 MEAN ANNUAL PRECIPITATION 10

152 MILES

7.9

1,200

1200-

1,220

90- 110-

305

11

11

10

DEPTH DESIGNATION RANGE BY DEPTH

20 80 90 100

650- 950-

1,000

30- 100-

895

1000-

1,083

1083-

1,100

895-

950

0- 10- 70- 80-

1219.6-

1,229

1100-

1,150

1150- 

7.7

70.3 6 572

27.4

31.5 9.7

18.9 5.4 17.6 14.4

20-

30

60-

70

50-

10 40 60

PERCENT OF TOTAL SEDIMENT LOCATED WITHIN REACH DESIGNATION

10/14/64

0.30

9/01

9/30/48 879 65 6

DEAD

10/14/64

PER.

YRS

PER.

14

85

a. MEAN ANN.

a.

66.7

34.

37

0.11 7.4

1,287,140

-219,150

9/30/48

80,446

-5,923 15

10/14/64

9/01 2,402,770

0.48

-0.06

9/01 20,758,000 727,017,000

a. TOTAL

10,900,000

 /MI.2

-YR.

12,526,000

10,083,000

10,549,000

18,160,000

12,526,000 17,260,000

1205.4

ACRE-FEET

TOP OF DAM ELEVATION

10-ft

D

A

1

23 W

STREAM

3 30N RANGE NEAREST P.O.

b.

PERIOD PERIOD WATER INFLOW, ACRE-FEET

MAX. ANN. c.

14.

1,229.0

1,219.6

1,498,503

M

TWP.

B

A

R

E

S

E

STORAGE

ALLOCATION

S

R

V

O

I

R

156,619

162,585

SURFACE AREA, AC-FT

ORIGINAL 13. ORIGINAL 

13

161,335,000

390,320,000

1,083.0

895.0

91,006

Contour (D) 10-ft

 

336,697,000

33,392

73 26 °F RANGE

11,337,000

11

29,759,860

29,979,010 2.75

2.85

2.73

to 107

33.

b.

RATIO AF/AF

32,381,780 2.97

b. AVG. ANN.

2,621,920

PERIOD AVG. ANNUAL

 /MI. a. TOTAL 2 c. -YR.

TYPE OF 

SURVEY

I

N

S

U YRS

30,883,277

11,091,319

3,204,531

16,587,427

OF

SURVEY

A

T

Y

9/01

SURVEY

26. 44.

10/64

REACH DESIGNATION PERCENT OF TOTAL ORIGINAL LENGTH OF RESERVOIR

0.6 0.1

DATE

OF

SURVEY

RESERVOIR SEDIMENT

DATA SUMMARY

Lake Mead (Hoover Dam) NAME OF RESERVOIR

DATA SHEET NO.

DATE

STORAGE

BEGAN

DATE NORMAL

2/1/35

OPERATIONS

BEGAN

MAX. ELEVATION 14,400 MIN. ELEVATION 8959 ANNUAL TEMP, MEAN

3/1/36

WATER INFLOW TO DATE, AF

SURVEY

PERIOD CAPACITY LOSS, ACRE-FEET TOTAL SEDIMENT DEPOSITS TO DATE, AF

ANNUAL

PRECIPITATION

TOTAL

AVG. ANN. c.

R

SURVEY

V 13.7 13.7 9/30/48

D

1232.0

1,232.0

MILES

SQUARE MILES

14,295,850

3,204,531

482,000 32,863,780

32,381,780

162,585

AREA, AC.

10

NO. OF

RANGES OR 

INTERVALS

10,900,000

ACRE - FEET

SURFACE 32. CAPACITY

2/1/35

10.0 20.9

Contour (D) 10-ft

SURVEY

26.

DATE

5.3 16.3 6.3 0.0 0.0 

Table 4 - Reservoir sediment data summary (page 1 of 2). 
2001 Lake Mead Sedimentation Survey 

82

 

1

2

3 Values for El. 1229.0 and below, original surface areas and recomputed capacity using ACAP. El. 1232 value from Allocation Tables. 4

5

1935-2001 study period is 171,700 mi2 - (3,959 mi2) - (38.5 years/66.7 years)(107,741 mi2). 66.7 years since Hoover Dam Closure.

38.5 years since Glen Canyon Dam closure.

6

7

8

located about 145 river miles above Lake Mead.

9

10

11

12

13

14 Item 37c from 1948 and 1964 used net sediment contributing area of 167,600 square miles as reported in 1964 study. 15 9/01 study reported greater capacities than 63-64 study. Attributed to significant decrease of sediment inflow due to closure of 

Glen Canyon Dam and 37 years of compaction of the sediment deposition since 1963-64 survey. Different methods of collection and 

analysis between the studies attributes to some of the differences, but even though 2001 survey collected much greater detail the reported

computed results in this table used similar analysis approach as the 1948-49 and 1963-64 studies. Analyze of the upper Colorado River delta

growth measured around 267,000 AF of sediment deposition since 1963-64. Resulting in an annual average sediment inflow of 7,200 AF. 

16

 

1963

ELEVATION AREA CAPACITY

1,193.8

1,204.8

1,225.8

1977 1,175.8

1983

0 0 670

107,838 720 4,767

0

16

670 867 6,611

46.

1,140

740

770

46. ELEVATION - AREA - CAPACITY - DATA FOR

156,473

710 4,131

1,220 156,834

Previous studies report total drainage area as 167,800 mi2

. USGS gage data at dam indicate 171,700 mi2 with 3,959 mi2 located

above Lake Powell as non contributing. 1963-64 study indicated net sediment contributing area of 167,00 mi2

. The 1963-64 study completed 

47. REMARKS AND REFERENCES

All elevations (El.) are project datum, referred to as powerhouse datum. Add 0.55 feet to convert to NGVD29. Top parapet wall, El. 1,236.0.

Top spillway gate in raised position of overflow weir for each abutment is El. 1,221.4.

Values from 1963-64 report. Colorado River about 121 miles and Overton Arm about 31 miles. 

163,223 30,141,900

AGENCY SUPPLYING DATA DATE

Reported as 10-ft contour survey. 2001 survey used multibeam collection system to develop detailed contours of the original river channel

area affected by sediment deposition from the dam to the upper reaches just below El.1,190. Previous collected cross sections (1999-2001)

49. Bureau of Reclamation February 2008

48. Bureau of Reclamation AGENCY MAKING SURVEY

Original surface areas as listed in the 1963-64 study report. Capacities recomputed using BOR program ACAP.

1935

1,200

1,220

YEAR MAX. ELEV.

650 0

150,919

660

750

1,150

4,781

25

126,664 22,827,370

prior to the closure of Glen Canyon Dam, 3/63, with a total drainage area of 111,700 square miles. The net sediment contributing area for

1,229 162,548 29,979,010

Values from 1963-64 report.

Value from 1963-64 report and USGS gage, Colorado River near Grand Canyon located about 145 river miles above Lake Mead. 

This calculation for only Colorado River upper delta growth. Additional analyses needed to calculate other tributaries and lower reservoir area. 

were used to measure change on the Colorado River above El 1,190 in the Lower Gorge.

Calculated using mean annual runoff value of 10,900,000 AF (item 24).

Estimated mean annual runoff for 2/35 through 9/01 equals 10,900,000 AF, measured by USGS gage, Colorado River near Grand Canyon 

Dead pool elevation.

Surface area in acres at elevation 1,229.0. Trouble locating 1948 area/capacity tables that matched different past reports.

Capacity at El. 1,229.0 for given year. Capacity recomputed for 1935 and 1964 using BOR program ACAP.

MIN. ELEV. INFLOW, AF YEAR MAX. ELEV. MIN. ELEV. INFLOW, AF

1953

673.5

1,145.8 8,879,000

928.4 1936 1,025.8 905.2 12,320,000

0

27,920,820

1954

1,165.1

1,193.1

1,181.0

1,145.7 1,105.4 6,229,000

1955 1,089.5 7,580,000 1,117.0 1956

1,169.0

1,106.7

1,205.9

1,083.2 8,860,000

1957 1,089.6 17,500,000 1958 1,161.0 14,550,000 1,184.1

1959 1,167.3 6,935,000 1960 1,185.8 1,184.2 1,163.0 9,584,000

1961 1,152.9 7,050,000 1962 1,204.2 1,153.1 15,250,000

2,727,000

1975 1,173.6 9,529,000 1976 1,188.3 1,177.6 8,735,000

1,136.8 2,742,000

1978 1,193.3 1,180.8

1964 1,136.8 1,088.1

1972 1,168.4 1,154.0

1,180.2

8,457,000

1981 1,192.4 8,224,000 1982 1,208.4 1,196.2 8,788,000

11,440,000

8,537,000

1,206.8 17,680,000 1984 1,213.7 1,205.7 20,758,000

1987 1,210.8 1,205.6 13,680,000 1988 1,211.8 1,199.1 6,937,000

1989 1,202.6 1,189.0 8,275,000 1990 1,191.8 1,177.9 8,446,000

1991 1,180.2 1,172.7 8,544,000 1992 1,180.6 1,173.4 8,487,000

1993 1,193.8 1,176.9 8,815,000 1994 1,191.0 1,175.7 8,387,000

1995 1,190.0 1,176.6 9,671,000 1,189.7 11,860,000

1997 1,214.6 1,194.4 12,240,000

AREA

9,936,000

ELEVATION CAPACITY

690 2,536 69,578 39,290 700 3,521

1,138

CAPACITY

660 228

AREA

ELEVATION - AREA - CAPACITY - DATA FOR

 

650

111,056 19,278,840

69,610

263,560

15,235

20,557

1,350

5,985

9,664

820 17,087

54 314 730

880

790

900

1,230

1,160

1,190

29,403,630 156,250

 

ELEVATION AREA CAPACITY

28,480,870

1,230 163,224

57,472

67,223

1,050 77,895

1,219.6

1,080 89,760

1,100 97,833

1,210 151,321

20,412,530

24,138,460

32,544,690

7,333

123,437

720

2001 Capacity

418,927

5,271 202,519

760 9,270

30,944,400 32,381,780

259,800

710 4

ELEVATION AREA CAPACITY

1973

45. RANGE IN RESERVOIR OPERATION

145,240

28,543,420

18,778

1971 1,160.1 1,148.0 8,837,000 9,540,000

1,187.0 1,168.4 11,230,000 1974 1,168.8 8,449,000

1965 1,129.7 1,088.0 10,980,000 1966 1,133.8 1,127.2 8,328,000

1967 1,133.8 1,127.8 8,257,000 1968 1,139.6 1,129.8 8,939,000

1969 1,152.5 1,139.4 9,286,000 1970 1,154.2 1,150.4 9,123,000

105,824 18,194,440 115,683

1,170 120,310 21,592,490 1,180 135,555

ELEVATION AREA CAPACITY

0

760

1,202.8 1,193.4 9,068,000

1,229 162,585

Original Capacity

ELEVATION

1,205.0 1,197.6

1999 1,214.0 1,206.4 11,700,000

1,201.4

1996 1,195.0

1979

2000

13,800,000

 

1998 1,216.0 1,211.4

1,214.4 1,196.3

680 1,566

1,197.5 1,177.2 8,797,000 

1,182.5 1,146.6

1985 1,214.4 1,205.5 19,320,000 1986 1,213.2 17,240,000

1980

1938 1,173.9 1,094.6

2001

1937 1,102.9 1,021.9

1941 1,220.4 1,166.8

15,630,000

1939 1,183.4 1,156.1 9,618,000 1940 1182.2 1,164.2 7,435,000

12,410,000

16,940,000 1942 1,213.4 1,171.0

1943 1,202.4 1,176.7 11,430,000

1946 1,164.3 1,146.5

17,260,000

1944 1,200.4 1,157.2 13,530,000

9,089,000

1948 1,192.8 1,154.5 13,870,000

11,870,000

1949 1,196.6 1,145.5 14,370,000

1947 1,180.2 1,133.9 13,740,000

1945

1950 1,177.5 1,150.0 11,080,000

1951 1,169.0 1,141.2 9,839,000 1952 1,201.1 1,133.2 18,160,000

152,328 730

740 6,185 750 8,185 331,651

770 10,515 517,855 780 11,937 630,118 790 13,499 757,299

800 15,530 902,445 810 17,271 1,066,450 820 19,046 1,248,036

830 20,776 1,447,147 840 22,473 1,663,392 850 24,712 1,899,317

860 26,674 2,156,244 870 28,491 2,432,068 880 30,360 2,726,322

890 32,391 3,040,074 895 33,392 3,204,531 900 34,393 3,373,994

910 36,888 3,730,401 920 39,303 4,111,359 930 41,656 4,516,153

940 43,989 4,944,377 950 46,427 5,396,458 960 49,047 5,873,827

970 51,477 6,376,447 980 54,439 6,906,028 990 7,465,581

1,000 60,528 8,055,581 1,010 64,037 8,678,404 1,020 9,334,704

1,030 70,658 10,024,110 1,040 74,177 10,748,280 11,508,640

1,060 81,873 12,307,470 1,070 85,907 13,146,370 14,024,700

1,083 91,006 14,295,850 1,090 93,914 14,943,080 15,901,810

1,110 102,044 16,901,200 1,120 106,083 17,941,830 1,130 110,381 19,024,150

1,140 114,509 20,148,600 1,150 119,448 21,318,380 1,160 124,470 22,537,980

1,170 129,359 23,807,120 1,180 1,190 139,506 134,565 25,126,740 26,497,100

680 0 0 0 700 0 3

0

 

11,746,040

13,403,540

16,160,740

0

690 0

3,162 29,895

6,908 187,902 780 8,223 352,997

800 13,266 467,648 810 610,149 771,758

830 18,724 950,812 840 1,147,216 22,540 850 1,362,705

860 24,296 1,596,886 870 25,877 1,847,750 27,503 2,114,651

890 29,191 2,398,124 895 30,172 2,546,532 31,152 2,699,843

910 33,565 3,023,428 920 35,922 3,370,863 930 38,203 3,741,490

940 40,527 4,135,140 950 42,869 4,552,117 960 45,461 4,993,767

970 47,847 5,460,304 980 50,525 5,952,162 990 53,518 6,472,374

1,000 56,374 7,021,833 1,010 59,475 7,601,082 1,020 62,533 8,211,125

1,030 65,624 8,851,909 1,040 68,834 9,524,197 1,050 72,208 10,229,410

1,060 75,832 10,969,620 1,070 79,451 1,080 82,849 12,557,510

1,083 83,902 12,807,630 1,090 86,358 1,100 89,814 14,284,400

1,110 93,860 15,202,770 1,120 97,731 1,130 101,596 17,157,370

 

1,200 143,563 25,534,050 1,210 27,006,460 28,480,870 1,219.6 156,250

Table 4 - Reservoir sediment data summary (page 2 of 2).
83

1 2 3 4 5 6 7 8 9 10 11 12 

 P

 Original Original 1947-48 1947-48 1963-64 1963-64 2001 2001 Sediment Sediment Sediment Se

Elevation Survey Capacity Survey Survey Survey Survey Survey Survey Orig - 1964 Orig - 2001 1963-2001 

Feet Acres Ac-Ft Acres Ac-Ft Acres Ac-Ft Acres Ac-Ft Ac - Ft Ac-Ft Ac-Ft Or

1,229.0 162,585 32,381,780 162,677 31,047,000 162,608 29,759,860 162,548 29,979,010 2,621,920 2,402,770 -219,150 1,220.0 156,834 30,944,400 157,736 29,606,000 157,073 28,321,300 156,473 28,543,420 2,623,100 2,400,980 -222,120 1,219.6 156,613 30,881,710 156,839 29,458,000 156,839 28,258,510 156,250 28,480,870 2,623,200 2,400,840 -222,360 1,200.0 145,240 27,920,820 145,100 26,583,000 144,892 25,299,240 143,563 25,534,050 2,621,580 2,386,770 -234,810 1,175.0 131,962 24,460,420 128,960 23,152,000 128,960 21,871,640 123,487 22,201,990 2,588,780 2,258,430 -330,350 1,150.0 119,448 21,318,380 115,500 20,103,000 111,551 18,861,810 111,056 19,278,840 2,456,570 2,039,540 -417,030 1,125.0 108,232 18,477,620 99,540 17,350,000 99,540 16,232,550 99,663 16,654,230 2,245,070 1,823,390 -421,680 1,100.0 97,833 15,901,810 94,700 14,852,000 89,471 13,872,210 89,814 14,284,400 2,029,600 1,617,410 -412,190 1,083.0 91,006 14,295,850 83,261 13,297,000 83,261 12,405,420 83,902 12,807,630 1,890,430 1,488,220 -402,210 1,075.0 87,833 13,580,720 80,431 12,604,000 80,431 11,750,510 81,148 12,147,520 1,830,210 1,433,200 -397,010 1,050.0 77,895 11,508,640 75,400 10,594,000 71,160 9,852,651 72,208 10,229,410 1,655,989 1,279,230 -376,759 1,025.0 68,941 9,675,114 62,712 8,822,000 62,712 8,183,496 64,078 8,527,654 1,491,618 1,147,460 -344,158 1,000.0 60,528 8,055,581 58,300 7,262,000 54,816 6,712,890 56,374 7,021,833 1,342,691 1,033,748 -308,943 

975.0 52,958 6,637,536 47,898 5,902,000 47,898 5,434,287 49,186 5,702,885 1,203,249 934,651 -268,598 950.0 46,427 5,396,458 41,567 4,715,000 41,567 4,314,975 42,869 4,552,117 1,081,483 844,341 -237,142 925.0 40,479 4,310,816 35,762 3,679,000 35,762 3,349,568 37,063 3,553,325 961,248 757,491 -203,757 900.0 34,393 3,373,994 29,950 2,783,000 29,950 2,526,955 31,152 2,699,843 847,039 674,151 -172,888 895.0 33,392 3,204,531 28,911 2,620,000 28,911 2,379,801 30,172 2,546,532 824,730 657,999 -166,731 875.0 29,425 2,576,859 27,000 1,500,000 25,598 1,837,206 26,690 1,979,168 739,653 597,691 -141,962 850.0 24,712 1,899,317 23,000 1,200,000 21,530 1,246,022 22,540 1,362,705 653,295 536,612 -116,683 825.0 19,911 1,345,430 18,000 700,000 16,914 767,712 17,905 859,239 577,718 486,191 -91,527 800.0 15,530 902,445 13,000 400,000 12,326 397,744 13,266 467,648 504,701 434,797 -69,904 775.0 11,226 572,209 7,500 178,000 6,702 178,186 7,566 224,088 394,023 348,121 -45,902 750.0 8,185 331,651 7,000 42,300 4,151 42,282 4,781 69,610 289,369 262,041 -27,328 725.0 5,019 176,794 10 400 31 387 702 2,203 176,407 174,591 -1,816 700.0 3,521 69,578 0 0 0 0 0 3 69,578 69,575 -3 675.0 1,217 11,820 0 0 0 0 0 0 11,820 11,820 0 650.0 0 0 0 0 0 0 0 0 0 0 0 

1 Elevation of reservoir water surface. Tied to "Power House" datum. Add 0.55 feet to convert to NGVD29, from leveling of 1935.2 Original reservoir surface areas, in acres.3 Original reservoir capacity recomputed using ACAP, in acre-feet.4 1947-48 measured reservoir surface area, in acres. Questions on surface areas to use. Published results varied slightly.5 1947-48 reservoir capacity in acre-feet. Found slightly different published results. Some values projected from 1963-64 report.6 1963-64 measured reservoir surface areas in acres.7 1963-64 reservoir capacity recomputed by ACAP, in acre-feet.8 2001 measured reservoir surface areas, in acres.9 2001 reservoir capacity computed by ACAP, in acre-feet.

10 Computed sediment volume from original (1935) through 1964, acre-feet.11 Computed sediment volume from original (1935) through 2001, acre-feet.12 2001 change in volume, column (7) - column (9). Negative values indicate increase in capacity due to sediment compaction and much less 

13 Measured sediment in percentage my elevation from original to 2006. Total sediment volume of 6,473 acre-feet.

 sediment inflow due to closure of Glen Canyon Dam in 1963.

14 Measured sediment in percent from original, 1935, to 2001. Total sediment volume 2,402,770 acre-feet.15 Depth of reservoir expressed in percentage of total depth (579). 

Table 5 - Reservoir sediment summary. 
2001 Lake Mead Sedimentation Survey 

84
85

Elevation Boulder and Virgin Basins

1935 1948 1963 2001 1935-1948 1948-1963 1963-2001 1935-2001

 Reservoir Capacity (AF) Computed Sediment Volume (AF)

660 1,138 1,138 1,138

670 6,611 6,611 6,611

680 18,778 18,778 18,778

690 39,290 0 39,290 0 39,290

700 69,578 0 3 69,578 0 -3 69,575

710 107,838 62 25 107,838 -62 37 107,813

720 152,328 247 314 152,328 -247 -67 152,014

730 202,519 557 7,333 202,519 -557 -6,776 195,186

740 259,800 0 11,136 29,894 259,800 -11,136 -18,758 229,906

750 331,651 15,000 42,282 69,610 316,651 -27,282 -27,328 262,041

760 417,937 69,000 89,148 123,437 348,937 -20,148 -34,289 294,500

770 514,873 124,000 146,041 187,902 390,873 -22,041 -41,861 326,971

780 623,150 213,000 213,060 263,560 410,150 -60 -50,500 359,590

790 742,352 312,000 292,705 352,997 430,352 19,295 -60,292 389,355

800 874,524 441,000 397,744 467,648 433,524 43,256 -69,904 406,876

810 1,023,552 589,000 531,832 610,149 434,552 57,168 -78,317 413,403

820 1,188,082 752,000 685,001 771,251 436,082 66,999 -86,250 416,831

830 1,364,196 928,000 852,783 947,196 436,196 75,217 -94,413 417,000

840 1,553,366 1,116,000 1,033,058 1,135,072 437,366 82,942 -102,014 418,294

850 1,755,293 1,318,000 1,226,231 1,335,932 437,293 91,769 -109,701 419,361

860 1,970,223 1,533,000 1,433,023 1,550,413 437,223 99,977 -117,390 419,810

870 2,197,965 1,760,000 1,652,515 1,777,392 437,965 107,485 -124,877 420,573

880 2,438,182 2,000,000 1,883,848 2,017,082 438,182 116,152 -133,234 421,100

890 2,690,951 2,253,000 2,126,659 2,269,693 437,951 126,341 -143,034 421,258

900 2,955,871 2,518,000 2,382,025 2,534,660 437,871 135,975 -152,635 421,211

910 3,235,215 2,797,000 2,651,111 2,813,466 438,215 145,889 -162,355 421,749

920 3,530,167 3,092,000 2,935,024 3,107,545 438,167 156,976 -172,521 422,622

930 3,837,980 3,400,000 3,234,794 3,416,642 437,980 165,206 -181,848 421,338

940 4,162,159 3,724,000 3,549,390 3,740,523 438,159 174,610 -191,133 421,636

950 4,499,216 4,061,000 3,877,572 4,078,495 438,216 183,428 -200,923 420,721

960 4,851,683 4,414,000 4,220,395 4,430,670 437,683 193,605 -210,275 421,013

970 5,218,366 4,781,000 4,577,565 4,797,271 437,366 203,435 -219,706 421,095

980 5,599,644 5,161,000 4,948,799 5,178,216 438,644 212,201 -229,417 421,428

990 5,994,466 5,557,000 5,334,186 5,573,694 437,466 222,814 -239,508 420,772

1000 6,406,257 5,968,000 5,734,763 5,983,994 438,257 233,237 -249,231 422,263

1010 6,833,105 6,395,000 6,152,535 6,410,464 438,105 242,465 -257,929 422,641

1020 7,277,108 6,838,000 6,587,004 6,853,602 439,108 250,996 -266,598 423,506

1030 7,736,628 7,298,000 7,037,820 7,313,398 438,628 260,180 -275,578 423,230

1040 8,213,743 7,775,000 7,505,226 7,790,156 438,743 269,774 -284,930 423,587

1050 8,705,997 8,267,000 7,989,441 8,283,536 438,997 277,559 -294,095 422,461

1060 9,215,849 8,777,000 8,491,653 8,793,439 438,849 285,347 -301,786 422,410

1070 9,740,756 9,302,000 9,018,219 9,319,801 438,756 283,781 -301,582 420,955

1080 10,282,980 9,844,000 9,544,624 9,862,788 438,980 299,376 -318,164 420,192

1090 10,842,509 10,404,000 10,095,815 10,423,264 438,509 308,185 -327,449 419,245

1100 11,419,299 10,981,000 10,664,746 11,001,398 438,299 316,254 -336,652 417,901

1110 12,014,564 11,576,000 11,251,489 11,597,491 438,564 324,511 -346,002 417,073

1120 12,626,992 12,188,000 11,854,039 12,211,986 438,992 333,961 -357,947 415,006

1130 13,257,498 12,819,000 12,472,062 12,844,541 438,498 346,938 -372,479 412,957

1140 13,905,795 13,467,000 13,106,619 13,494,717 438,795 360,381 -388,098 411,078

1150 14,571,311 14,132,000 13,761,553 14,163,314 439,311 370,447 -401,761 407,997

1160 15,256,694 14,872,000 14,445,823 14,851,758 384,694 426,177 -405,935 404,936

1170 15,961,763 15,522,000 15,149,340 15,560,503 439,763 372,660 -411,163 401,260

1180 16,688,812 16,248,000 15,872,538 16,289,961 440,812 375,462 -417,423 398,851

1190 17,432,724 16,995,000 16,615,865 17,040,320 437,724 379,135 -424,455 392,404

1200 18,197,534 17,760,000 17,379,212 17,811,666 437,534 380,788 -432,454 385,868

1210 18,984,407 18,547,000 18,165,052 18,606,224 437,407 381,948 -441,172 378,183

1220 19,796,616 19,360,000 18,974,393 19,424,828 436,616 385,607 -450,435 371,788

1230 20,630,536 20,195,000 19,806,002 20,266,660 435,536 388,998 -460,658 363,876

 

 Table 6 - Sediment analysis by basins, page 1 of 8. 
2001 Lake Mead Sedimentation Survey 

86

Elevation Temple Bar area and Virgin Canyon

1935 1948 1963 2001 1935-1948 1948-1963 1963-2001 1935-2001

 Reservoir Capacity (AF) Computed Sediment Volume (AF)

660 

670 

680 

690 

700 

710 

720 

730 

740 

750 0 0

760 990 990 990

770 2,982 2,982 2,982

780 6,968 6,968 6,968

790 14,947 14,947 14,947

800 26,924 26,924 26,924

810 40,902 0 0 40,902 0 0 40,902

820 56,956 6,000 47 507 50,956 5,953 -460 56,449

830 75,955 19,000 1,402 3,616 56,955 17,598 -2,214 72,339

840 95,022 36,000 7,410 12,144 59,022 28,590 -4,734 82,878

850 116,019 57,000 19,791 26,773 59,019 37,209 -6,982 89,246

860 139,016 80,000 37,072 46,470 59,016 42,928 -9,398 92,546

870 164,072 105,000 58,466 70,336 59,072 46,534 -11,870 93,736

880 191,093 132,000 83,106 97,224 59,093 48,894 -14,118 93,869

890 220,078 161,000 110,331 126,508 59,078 50,669 -16,177 93,570

900 251,074 192,000 139,931 158,037 59,074 52,069 -18,106 93,037

910 285,107 226,000 171,729 191,831 59,107 54,271 -20,102 93,276

920 321,106 262,000 205,629 227,998 59,106 56,371 -22,369 93,108

930 360,092 301,000 241,638 266,551 59,092 59,362 -24,913 93,541

940 401,112 342,000 279,827 307,479 59,112 62,173 -27,652 93,633

950 445,120 386,000 320,665 350,922 59,120 65,335 -30,257 94,198

960 491,069 432,000 364,387 397,248 59,069 67,613 -32,861 93,821

970 540,038 481,000 410,912 446,359 59,038 70,088 -35,447 93,679

980 591,174 532,000 459,917 498,102 59,174 72,083 -38,185 93,072

990 647,050 588,000 511,418 552,928 59,050 76,582 -41,510 94,122

1000 705,138 646,000 565,916 610,967 59,138 80,084 -45,051 94,171

1010 766,124 707,000 624,023 672,417 59,124 82,977 -48,394 93,707

1020 830,241 771,000 685,763 736,856 59,241 85,237 -51,093 93,385

1030 899,189 840,000 750,955 804,067 59,189 89,045 -53,112 95,122

1040 969,206 910,000 819,825 874,449 59,206 90,175 -54,624 94,757

1050 1,043,239 984,000 892,160 948,037 59,239 91,840 -55,877 95,202

1060 1,121,225 1,062,000 968,214 1,025,144 59,225 93,786 -56,930 96,081

1070 1,202,217 1,143,000 1,049,252 1,105,902 59,217 93,748 -56,650 96,315

1080 1,288,248 1,229,000 1,132,296 1,190,233 59,248 96,704 -57,937 98,015

1090 1,377,192 1,318,000 1,220,070 1,278,080 59,192 97,930 -58,010 99,112

1100 1,470,167 1,411,000 1,312,151 1,369,820 59,167 98,849 -57,669 100,347

1110 1,567,204 1,508,000 1,408,990 1,465,840 59,204 99,010 -56,850 101,364

1120 1,669,263 1,610,000 1,510,767 1,565,672 59,263 99,233 -54,905 103,591

1130 1,775,201 1,716,000 1,617,266 1,669,155 59,201 98,734 -51,889 106,046

1140 1,885,243 1,826,000 1,727,956 1,776,190 59,243 98,044 -48,234 109,053

1150 1,999,317 1,940,000 1,843,322 1,886,876 59,317 96,678 -43,554 112,441

1160 2,116,374 2,057,000 1,963,857 2,001,376 59,374 93,143 -37,519 114,998

1170 2,239,388 2,180,000 2,087,846 2,119,221 59,388 92,154 -31,375 120,167

1180 2,365,540 2,306,000 2,215,790 2,240,409 59,540 90,210 -24,619 125,131

1190 2,495,104 2,436,000 2,348,127 2,365,313 59,104 87,873 -17,186 129,791

1200 2,630,077 2,571,000 2,484,998 2,494,060 59,077 86,002 -9,062 136,017

1210 2,769,059 2,710,000 2,626,564 2,626,800 59,059 83,436 -236 142,259

1220 2,911,944 2,853,000 2,772,075 2,762,961 58,944 80,925 9,114 148,983

1230 3,058,783 3,000,000 2,921,521 2,902,552 58,783 78,479 18,969 156,231

Table 6 – Sediment analysis by basin, page 2 of 8. 
87

Elevation Gregg Basin

1935 1948 1963 2001 1935-1948 1948-1963 1963-2001 1935-2001

 Reservoir Capacity (AF) Computed Sediment Volume (AF)

660 

670 

680 

690 

700 

710 

720 

730 

740 

750 

760 

770 

780 

790 0 0 0

800 997 997 997

810 1,995 1,995 1,995

820 2,998 2,998 2,998

830 6,996 6,996 6,996

840 15,004 15,004 15,004

850 28,005 0 0 28,005 0 0 28,005

860 46,005 1,000 3 45,005 1,000 -3 46,002

870 68,030 5,000 0 22 63,030 5,000 -22 68,008

880 92,045 15,000 3 333 77,045 14,997 -330 91,712

890 120,042 31,000 613 1,598 89,042 30,387 -985 118,444

900 150,044 53,000 3,923 5,881 97,044 49,077 -1,958 144,163

910 182,068 79,000 13,327 15,282 103,068 65,673 -1,955 166,786

920 215,071 108,000 28,477 29,931 107,071 79,523 -1,454 185,140

930 251,064 141,000 47,200 48,947 110,064 93,800 -1,747 202,117

940 291,081 178,000 69,753 72,031 113,081 108,247 -2,278 219,050

950 332,090 218,000 96,799 99,254 114,090 121,201 -2,455 232,836

960 375,053 261,000 127,863 130,407 114,053 133,137 -2,544 244,646

970 419,029 305,000 162,558 165,308 114,029 142,442 -2,750 253,721

980 467,137 353,000 200,814 203,818 114,137 152,186 -3,004 263,319

990 516,040 402,000 242,534 246,592 114,040 159,466 -4,058 269,448

1000 567,111 453,000 287,541 293,360 114,111 165,459 -5,819 273,751

1010 621,100 507,000 336,159 343,044 114,100 170,841 -6,885 278,056

1020 678,196 564,000 388,598 396,018 114,196 175,402 -7,420 282,178

1030 736,155 622,000 444,241 452,234 114,155 177,759 -7,993 283,921

1040 797,169 683,000 502,594 511,175 114,169 180,406 -8,581 285,994

1050 861,198 747,000 564,040 573,111 114,198 182,960 -9,071 288,087

1060 928,186 814,000 628,829 638,350 114,186 185,171 -9,521 289,836

1070 998,180 884,000 697,282 706,882 114,180 186,718 -9,600 291,298

1080 1,069,206 955,000 767,260 778,269 114,206 187,740 -11,009 290,937

1090 1,144,159 1,030,000 840,586 852,775 114,159 189,414 -12,189 291,384

1100 1,222,139 1,108,000 917,103 930,750 114,139 190,897 -13,647 291,389

1110 1,303,170 1,189,000 997,000 1,011,919 114,170 192,000 -14,919 291,251

1120 1,387,219 1,273,000 1,079,892 1,095,993 114,219 193,108 -16,101 291,226

1130 1,474,167 1,360,000 1,165,461 1,182,910 114,167 194,539 -17,449 291,257

1140 1,564,202 1,450,000 1,253,848 1,272,636 114,202 196,152 -18,788 291,566

1150 1,656,263 1,542,000 1,345,955 1,365,235 114,263 196,045 -19,280 291,028

1160 1,752,309 1,638,000 1,442,077 1,460,872 114,309 195,923 -18,795 291,437

1170 1,851,320 1,737,000 1,540,446 1,559,214 114,320 196,554 -18,768 292,106

1180 1,951,446 1,837,000 1,641,248 1,660,047 114,446 195,752 -18,799 291,399

1190 2,055,085 1,941,000 1,744,566 1,763,442 114,085 196,434 -18,876 291,643

1200 2,161,063 2,047,000 1,850,547 1,869,569 114,063 196,453 -19,022 291,494

1210 2,270,049 2,156,000 1,959,459 1,978,728 114,049 196,541 -19,269 291,321

1220 2,380,954 2,267,000 2,070,959 2,090,702 113,954 196,041 -19,743 290,252

1230 2,494,823 2,381,000 2,184,907 2,205,417 113,823 196,093 -20,510 289,406

Table 6 – Sediment analysis by basin, page 3 of 8. 
2001 Lake Mead Sedimentation Survey 

88

Elevation Grand Bay

1935 1948 1963 2001 1935-1948 1948-1963 1963-2001 1935-2001

 Reservoir Capacity (AF) Computed Sediment Volume (AF)

660 

670 

680

690

700

710

720

730

740

750

760

770

780 

790 

800 

810 

820 

830 

840 

850 0 0 0

860 1,000 1,000 1,000

870 2,001 2,001 2,001

880 5,002 5,002 5,002

890 9,003 9,003 9,003

900 15,004 15,004 15,004

910 21,008 21,008 21,008

920 29,010 29,010 29,010

930 38,010 38,010 38,010

940 47,013 47,013 47,013

950 57,015 0 57,015 0 57,015

960 67,009 1,000 66,009 1,000 67,009

970 79,006 3,000 76,006 3,000 79,006

980 91,027 7,000 84,027 7,000 91,027

990 104,008 14,000 90,008 14,000 104,008

1000 118,023 24,000 94,023 24,000 118,023

1010 132,021 36,000 0 96,021 36,000 0 132,021

1020 148,043 51,000 2 97,043 50,998 2 148,043

1030 166,035 69,000 402 97,035 68,598 402 166,035

1040 184,039 87,000 1,582 97,039 85,418 1,582 184,039

1050 204,047 107,000 3,784 97,047 103,216 3,784 204,047

1060 224,045 127,000 7,064 97,045 119,936 7,064 224,045

1070 247,045 150,000 1,162 0 97,045 148,838 1,162 247,045

1080 271,052 174,000 16,600 41 97,052 157,400 16,559 271,011

1090 296,041 199,000 23,463 371 97,041 175,537 23,092 295,670

1100 323,037 226,000 31,226 1,138 97,037 194,774 30,088 321,899

1110 352,046 255,000 40,534 2,661 97,046 214,466 37,873 349,385

1120 383,060 286,000 53,019 6,063 97,060 232,981 46,956 376,997

1130 415,047 318,000 73,216 11,450 97,047 244,784 61,766 403,597

1140 450,058 353,000 101,770 21,140 97,058 251,230 80,630 428,918

1150 488,077 391,000 134,746 40,096 97,077 256,254 94,650 447,981

1160 527,093 430,000 172,461 67,310 97,093 257,539 105,151 459,783

1170 570,099 473,000 214,479 99,144 97,099 258,521 115,335 470,955

1180 613,140 516,000 258,808 137,002 97,140 257,192 121,806 476,138

1190 660,027 563,000 305,162 181,480 97,027 257,838 123,682 478,547

1200 708,021 611,000 353,708 229,661 97,021 257,292 124,047 478,360

1210 758,016 661,000 404,777 280,251 97,016 256,223 124,526 477,765

1220 811,984 715,000 458,309 333,204 96,984 256,691 125,105 478,780

1230 866,938 770,000 514,246 388,473 96,938 255,754 125,773 478,465

Table 6 – Sediment analysis by basin, page 4 of 8. 
89

Elevation Pierce Basin

1935 1948 1963 2001 1935-1948 1948-1963 1963-2001 1935-2001

 Reservoir Capacity (AF) Computed Sediment Volume (AF)

660

670

680

690

700

710

720 

730 

740 

750 

760 

770 

780 

790 

800 

810 

820 

830 

840 

850 

860 

870 

880 

890 0 0 0

900 1,000 1,000 1,000

910 3,001 3,001 3,001

920 6,002 6,002 6,002

930 11,003 11,003 11,003

940 16,004 16,004 16,004

950 22,006 22,006 22,006

960 29,004 29,004 29,004

970 36,003 36,003 36,003

980 44,013 44,013 44,013

990 52,004 52,004 52,004

1000 61,012 61,012 61,012

1010 71,011 71,011 71,011

1020 81,023 81,023 81,023

1030 91,019 0 91,019 0 91,019

1040 103,022 3,000 100,022 3,000 103,022

1050 117,027 9,000 108,027 9,000 117,027

1060 131,026 16,000 115,026 16,000 131,026

1070 146,026 27,000 119,026 27,000 146,026

1080 163,031 40,000 123,031 40,000 163,031

1090 181,025 54,000 127,025 54,000 181,025

1100 200,023 70,000 130,023 70,000 200,023

1110 222,029 88,000 134,029 88,000 222,029

1120 244,039 107,000 137,039 107,000 244,039

1130 268,030 129,000 139,030 129,000 268,030

1140 293,038 152,000 141,038 152,000 293,038

1150 319,051 177,000 0 142,051 177,000 0 319,051

1160 349,062 205,000 652 144,062 204,348 652 349,062

1170 378,065 234,000 21,992 144,065 212,008 21,992 378,065

1180 411,094 267,000 54,078 0 144,094 212,922 54,078 411,094

1190 445,018 301,000 88,548 12,995 144,018 212,452 75,553 432,023

1200 481,014 337,000 124,761 48,502 144,014 212,239 76,259 432,512

1210 519,011 375,000 162,686 94,481 144,011 212,314 68,205 424,530

1220 557,989 414,000 202,404 142,333 143,989 211,596 60,071 415,656

1230 599,957 456,000 244,127 192,146 143,957 211,873 51,981 407,811

Table 6 – Sediment analysis by basin, page 5 of 8. 
2001 Lake Mead Sedimentation Survey 

90

Elevation Lower Granite Gorge

1935 1948 1963 2001 1935-1948 1948-1963 1963-2001 1935-2001

 Reservoir Capacity (AF) Computed Sediment Volume (AF)

660 

670 

680 

690 

700 

710 

720 

730 

740 

750 

760 

770 

780 

790 

800 

810 

820 

830 

840 

850 

860 

870 

880 

890 

900 0 0 0

910 1,000 1,000 1,000

920 4,001 4,001 4,001

930 7,002 7,002 7,002

940 11,003 11,003 11,003

950 16,004 16,004 16,004

960 22,003 22,003 22,003

970 29,002 29,002 29,002

980 37,011 37,011 37,011

990 48,004 48,004 48,004

1000 59,012 59,012 59,012

1010 73,012 73,012 73,012

1020 87,025 87,025 87,025

1030 103,022 103,022 103,022

1040 120,025 120,025 120,025

1050 138,032 138,032 138,032

1060 159,032 159,032 159,032

1070 181,033 181,033 181,033

1080 204,039 204,039 204,039

1090 228,032 228,032 228,032

1100 255,029 255,029 255,029

1110 282,037 282,037 282,037

1120 311,049 311,049 311,049

1130 342,039 342,039 342,039

1140 375,048 0 375,048 0 0 375,048

1150 410,065 4 410,065 -4 4 410,065

1160 447,079 1,142 447,079 -1,142 1,142 447,079

1170 486,084 0 6,040 0 486,084 -6,040 6,040 486,084

1180 526,120 14,000 21,007 2,196 512,120 -7,007 18,811 523,924

1190 569,024 40,000 51,167 11,682 529,024 -11,167 39,485 557,342

1200 614,018 77,000 92,227 31,531 537,018 -15,227 60,696 582,487

1210 661,014 122,000 137,466 63,735 539,014 -15,466 73,731 597,279

1220 709,986 169,000 185,155 103,723 540,986 -16,155 81,432 606,263

1230 759,946 219,000 234,884 145,370 540,946 -15,884 89,514 614,576

Table 6 – Sediment analysis by basin, page 6 of 8. 
91

Elevation Overton Arm

1935 1948 1963 2001 1935-1948 1948-1963 1963-2001 1935-2001

 Reservoir Capacity (AF) Computed Sediment Volume (AF)

660 

670 

680 

690 

700 

710 

720 

730 

740 

750 

760 

770 

780 

790 

800 

810 

820 

830 

840 

850 

860 

870 0 0 0 0 0

880 1 12 -1 -11 -12

890 0 0 237 325 -237 -88 -325

900 1,000 1,000 1,077 1,265 0 -77 -188 -265

910 3,001 3,000 2,470 2,849 1 530 -379 152

920 6,002 6,000 4,503 5,389 2 1,497 -886 613

930 11,003 11,000 7,616 9,350 3 3,384 -1,734 1,653

940 16,004 16,000 12,499 15,107 4 3,501 -2,608 897

950 25,007 25,000 19,940 23,446 7 5,060 -3,506 1,561

960 38,005 38,000 30,996 35,442 5 7,004 -4,446 2,563

970 55,004 55,000 46,818 51,366 4 8,182 -4,548 3,638

980 76,022 76,000 67,299 72,026 22 8,701 -4,727 3,996

990 104,008 104,000 92,481 99,160 8 11,519 -6,679 4,848

1000 139,027 139,000 124,670 133,512 27 14,330 -8,842 5,515

1010 182,029 182,000 164,794 175,157 29 17,206 -10,363 6,872

1020 233,068 233,000 212,461 224,649 68 20,539 -12,188 8,419

1030 292,061 292,000 267,527 282,210 61 24,473 -14,683 9,851

1040 361,077 361,000 330,344 348,417 77 30,656 -18,073 12,660

1050 439,101 439,000 403,226 424,726 101 35,774 -21,500 14,375

1060 528,106 528,000 488,340 512,687 106 39,660 -24,347 15,419

1070 631,114 630,000 586,955 613,455 1,114 43,045 -26,500 17,659

1080 745,143 744,000 696,400 726,179 1,143 47,600 -29,779 18,964

1090 874,122 869,000 816,676 849,050 5,122 52,324 -32,374 25,072

1100 1,012,116 1,004,000 946,883 981,294 8,116 57,117 -34,411 30,822

1110 1,160,151 1,150,000 1,088,808 1,124,859 10,151 61,192 -36,051 35,292

1120 1,320,208 1,309,000 1,242,773 1,281,026 11,208 66,227 -38,253 39,182

1130 1,492,169 1,480,000 1,407,886 1,449,314 12,169 72,114 -41,428 42,855

1140 1,675,215 1,662,000 1,584,277 1,629,757 13,215 77,723 -45,480 45,458

1150 1,874,297 1,857,000 1,776,230 1,823,319 17,297 80,770 -47,089 50,978

1160 2,089,369 2,069,000 1,987,227 2,031,214 20,369 81,773 -43,987 58,155

1170 2,320,402 2,297,000 2,214,987 2,254,408 23,402 82,013 -39,421 65,994

1180 2,570,587 2,544,000 2,461,241 2,497,755 26,587 82,759 -36,514 72,832

1190 2,840,118 2,812,000 2,727,006 2,763,228 28,118 84,994 -36,222 76,890

1200 3,129,092 3,099,000 3,013,787 3,049,061 30,092 85,213 -35,274 80,031

1210 3,442,074 3,410,000 3,323,816 3,356,241 32,074 86,184 -32,425 85,833

1220 3,774,927 3,742,000 3,658,004 3,685,669 32,927 83,996 -27,665 89,258

1230 4,133,707 4,100,000 4,017,092 4,041,282 33,707 82,908 -24,190 92,425

Table 6 – Sediment analysis by basin, page 7 of 8. 
2001 Lake Mead Sedimentation Survey 

92

Elevation Total All Basins

1935 1948 1963 2001 1935-1948 1948-1963 1963-2001 1935-2001

 Reservoir Capacity (AF) Computed Sediment Volume (AF)

660 1,138 0 0 0 1,138 0 0 1,138

670 6,611 0 0 0 6,611 0 0 6,611

680 18,778 0 0 0 18,778 0 0 18,778

690 39,290 0 0 0 39,290 0 0 39,290

700 69,578 0 0 3 69,578 0 -3 69,575

710 107,838 0 62 25 107,838 -62 37 107,813

720 152,328 0 247 314 152,328 -247 -67 152,014

730 202,519 0 557 7,333 202,519 -557 -6,776 195,186

740 259,800 0 11,136 29,894 259,800 -11,136 -18,758 229,906

750 331,651 15,000 42,282 69,610 316,651 -27,282 -27,328 262,041

760 418,927 69,000 89,148 123,437 349,927 -20,148 -34,289 295,490

770 517,855 124,000 146,041 187,902 393,855 -22,041 -41,861 329,953

780 630,118 213,000 213,060 263,560 417,118 -60 -50,500 366,558

790 757,299 312,000 292,705 352,997 445,299 19,295 -60,292 404,302

800 902,445 441,000 397,744 467,648 461,445 43,256 -69,904 434,797

810 1,066,450 589,000 531,832 610,149 477,450 57,168 -78,317 456,301

820 1,248,036 758,000 685,048 771,758 490,036 72,952 -86,710 476,278

830 1,447,147 947,000 854,185 950,812 500,147 92,815 -96,627 496,335

840 1,663,392 1,152,000 1,040,468 1,147,216 511,392 111,532 -106,748 516,176

850 1,899,317 1,375,000 1,246,022 1,362,705 524,317 128,978 -116,683 536,612

860 2,156,244 1,614,000 1,470,095 1,596,886 542,244 143,905 -126,791 559,358

870 2,432,068 1,870,000 1,710,981 1,847,750 562,068 159,019 -136,769 584,318

880 2,726,322 2,147,000 1,966,958 2,114,651 579,322 180,042 -147,693 611,671

890 3,040,074 2,445,000 2,237,840 2,398,124 595,074 207,160 -160,284 641,950

900 3,373,994 2,764,000 2,526,955 2,699,843 609,994 237,045 -172,888 674,151

910 3,730,401 3,105,000 2,838,636 3,023,428 625,401 266,364 -184,792 706,973

920 4,111,359 3,468,000 3,173,633 3,370,863 643,359 294,367 -197,230 740,496

930 4,516,153 3,853,000 3,531,247 3,741,490 663,153 321,753 -210,243 774,663

940 4,944,377 4,260,000 3,911,468 4,135,140 684,377 348,532 -223,672 809,237

950 5,396,458 4,690,000 4,314,975 4,552,117 706,458 375,025 -237,142 844,341

960 5,873,827 5,146,000 4,743,642 4,993,767 727,827 402,358 -250,125 880,060

970 6,376,447 5,625,000 5,197,853 5,460,304 751,447 427,147 -262,451 916,143

980 6,906,028 6,129,000 5,676,830 5,952,162 777,028 452,170 -275,332 953,866

990 7,465,581 6,665,000 6,180,620 6,472,374 800,581 484,380 -291,754 993,207

1000 8,055,581 7,230,000 6,712,890 7,021,833 825,581 517,110 -308,943 1,033,748

1010 8,678,404 7,827,000 7,277,511 7,601,082 851,404 549,489 -323,571 1,077,322

1020 9,334,704 8,457,000 7,873,828 8,211,125 877,704 583,172 -337,297 1,123,579

1030 10,024,110 9,121,000 8,500,946 8,851,909 903,110 620,054 -350,963 1,172,201

1040 10,748,280 9,819,000 9,159,571 9,524,197 929,280 659,429 -364,626 1,224,083

1050 11,508,640 10,553,000 9,852,651 10,229,410 955,640 700,349 -376,759 1,279,230

1060 12,307,470 11,426,000 10,584,100 10,969,620 881,470 841,900 -385,520 1,337,850

1070 13,146,370 12,250,000 11,352,870 11,746,040 896,370 897,130 -393,170 1,400,330

1080 14,023,700 13,111,000 12,157,180 12,557,510 912,700 953,820 -400,330 1,466,190

1090 14,943,080 14,009,000 12,996,610 13,403,540 934,080 1,012,390 -406,930 1,539,540

1100 15,901,810 14,946,000 13,872,110 14,284,400 955,810 1,073,890 -412,290 1,617,410

1110 16,901,200 15,925,000 14,786,820 15,202,770 976,200 1,138,180 -415,950 1,698,430

1120 17,941,830 16,944,000 15,740,490 16,160,740 997,830 1,203,510 -420,250 1,781,090

1130 19,024,150 18,004,000 16,735,890 17,157,370 1,020,150 1,268,110 -421,480 1,866,780

1140 20,148,600 19,105,000 17,774,470 18,194,440 1,043,600 1,330,530 -419,970 1,954,160

1150 21,318,380 20,251,000 18,861,810 19,278,840 1,067,380 1,389,190 -417,030 2,039,540

1160 22,537,980 21,499,000 20,013,240 20,412,530 1,038,980 1,485,760 -399,290 2,125,450

1170 23,807,120 22,690,000 21,235,130 21,592,490 1,117,120 1,454,870 -357,360 2,214,630

1180 25,126,740 24,000,000 22,524,710 22,827,370 1,126,740 1,475,290 -302,660 2,299,370

1190 26,497,100 25,375,000 23,880,440 24,138,460 1,122,100 1,494,560 -258,020 2,358,640

1200 27,920,820 26,813,000 25,299,240 25,534,050 1,107,820 1,513,760 -234,810 2,386,770

1210 29,403,630 28,313,000 26,779,820 27,006,460 1,090,630 1,533,180 -226,640 2,397,170

1220 30,944,400 29,878,000 28,321,300 28,543,420 1,066,400 1,556,700 -222,120 2,400,980

1230 32,544,690 31,121,000 29,922,780 30,141,900 1,423,690 1,198,220 -219,120 2,402,790

Table 6 – Sediment analysis for all basins, page 8 of 8. 
93

Elevation 1935 1948-49 1963-64 2001 1948-1935 1963-1948 2001-1963 2001-1935

Contour Area Contour Area Contour Area Contour Area Contour Area Contour Area Contour Area Contour Area

Feet Acres Acres Acres Acres Acres Acres Acres Acres

660 228 0 0 0 -228 0 0 -228

670 867 0 0 0 -867 0 0 -867

680 1,566 0 0 0 -1,566 0 0 -1,566

690 2,536 0 0 0 -2,536 0 0 -2,536

700 3,521 0 0 0 -3,521 0 0 -3,521

710 4,131 0 12 4 -4,131 12 -8 -4,127

720 4,767 0 25 54 -4,767 25 29 -4,713

730 5,271 0 37 1,350 -5,271 37 1,313 -3,921

740 6,185 0 2,079 3,162 -6,185 2,079 1,083 -3,023

750 8,185 4,300 4,151 4,781 -3,885 -149 630 -3,404

760 9,270 6,000 5,223 5,985 -3,270 -777 762 -3,285

770 10,515 7,100 6,156 6,908 -3,415 -944 752 -3,607

780 11,937 8,700 7,248 8,223 -3,237 -1,452 975 -3,714

790 13,499 11,800 8,681 9,664 -1,699 -3,119 983 -3,835

800 15,530 13,800 12,326 13,266 -1,730 -1,474 940 -2,264

810 17,271 15,800 14,491 15,235 -1,471 -1,309 744 -2,036

820 19,046 18,000 16,152 17,087 -1,046 -1,848 935 -1,959

830 20,776 19,800 17,675 18,724 -976 -2,125 1,049 -2,052

840 22,473 21,400 19,581 20,557 -1,073 -1,819 976 -1,916

850 24,712 23,100 21,530 22,540 -1,612 -1,570 1,010 -2,172

860 26,674 24,800 23,285 24,296 -1,874 -1,515 1,011 -2,378

870 28,491 26,600 24,892 25,877 -1,891 -1,708 985 -2,614

880 30,360 28,800 26,303 27,503 -1,560 -2,497 1,200 -2,857

890 32,391 30,800 27,873 29,191 -1,591 -2,927 1,318 -3,200

900 34,393 33,000 29,950 31,152 -1,393 -3,050 1,202 -3,241

910 36,888 35,200 32,386 33,565 -1,688 -2,814 1,179 -3,323

920 39,303 37,400 34,613 35,922 -1,903 -2,787 1,309 -3,381

930 41,656 39,600 36,910 38,203 -2,056 -2,690 1,293 -3,453

940 43,989 41,900 39,134 40,527 -2,089 -2,766 1,393 -3,462

950 46,427 44,200 41,567 42,869 -2,227 -2,633 1,302 -3,558

960 49,047 46,800 44,166 45,461 -2,247 -2,634 1,295 -3,586

970 51,477 49,100 46,676 47,847 -2,377 -2,424 1,171 -3,630

980 54,439 51,900 49,119 50,525 -2,539 -2,781 1,406 -3,914

990 57,472 55,000 51,639 53,518 -2,472 -3,361 1,879 -3,954

1000 60,528 58,100 54,816 56,374 -2,428 -3,284 1,558 -4,154

1010 64,037 61,500 58,108 59,475 -2,537 -3,392 1,367 -4,562

1020 67,223 64,600 61,155 62,533 -2,623 -3,445 1,378 -4,690

1030 70,658 68,000 64,269 65,624 -2,658 -3,731 1,355 -5,034

1040 74,177 71,600 67,456 68,834 -2,577 -4,144 1,378 -5,343

1050 77,895 75,200 71,160 72,208 -2,695 -4,040 1,048 -5,687

1060 81,873 79,200 75,130 75,832 -2,673 -4,070 702 -6,041

1070 85,907 83,200 78,625 79,451 -2,707 -4,575 826 -6,456

1080 89,760 86,800 82,237 82,849 -2,960 -4,563 612 -6,911

1090 93,914 90,700 85,650 86,358 -3,214 -5,050 708 -7,556

1100 97,833 94,500 89,471 89,814 -3,333 -5,029 343 -8,019

1110 102,044 98,700 93,452 93,860 -3,344 -5,248 408 -8,184

1120 106,083 102,800 97,281 97,731 -3,283 -5,519 450 -8,352

1130 110,381 106,900 101,799 101,596 -3,481 -5,101 -203 -8,785

1140 114,509 110,800 105,917 105,824 -3,709 -4,883 -93 -8,685

1150 119,448 115,200 111,551 111,056 -4,248 -3,649 -495 -8,392

1160 124,470 120,200 118,733 115,683 -4,270 -1,467 -3,050 -8,787

1170 129,359 125,100 125,645 120,310 -4,259 545 -5,335 -9,049

1180 134,565 132,100 132,267 126,664 -2,465 167 -5,603 -7,901

1190 139,506 138,500 138,879 135,555 -1,006 379 -3,324 -3,951

1200 145,240 144,700 144,892 143,563 -540 192 -1,329 -1,677

1210 151,321 151,000 151,224 150,919 -321 224 -305 -402

1220 156,834 156,700 157,073 156,473 -134 373 -600 -361

1230 163,224 163,300 163,224 163,223 77 -76 -1 -1

Table 7 - Computed Contour Surface Area by Survey 
2001 Lake Mead Sedimentation Survey 

94
95

Area-Capacity Curves for Lake Mead

650.0700.0750.0800.0850.0900.0950.0

1,000.01,050.01,100.01,150.01,200.01,250.0

0 3300000 6600000 9900000 13200000 16500000 19800000 23100000 26400000 

Capacity (acre-feet)

Elevation (feet)

163,000 146,700 130,400 114,100 97,800 81,500 65,200 48,900 32,600 

Area (acres)

20011963-641947-48original

Figure 28 - Lake Mead Area and Capacity Curves. 
2001 Lake Mead Sedimentation Survey 

96
97

Elevation Boulder and Virgin Basins Temple Bar area and Gregg Basin Grand Bay Pierce Basin 

Virgin Canyon

1935 1948 1963 2001 1935 1948 1963 2001 1935 1948 1963 2001 1935 1948 1963 2001 1935 1948 1963 2001 1

660 1,138 

670 6,611 

680 18,778 

690 39,290 0 

700 69,578 3 

710 107,838 62 25 

720 152,328 247 314 

730 202,519 557 7,333 

740 259,800 11,136 29,895 

750 331,651 15,000 42,282 69,610 

760 417,937 69,000 89,148 123,437 990 

770 514,873 124,000 146,041 187,902 2,982 

780 623,150 213,000 213,060 263,560 6,968 

790 742,352 312,000 292,705 352,997 14,947 

800 874,524 441,000 397,744 467,648 26,924 997 

810 1,023,552 589,000 531,832 610,149 40,902 0 0 1,995 820 1,188,082 752,000 685,001 771,251 56,956 6,000 47 507 2,998 830 1,364,196 928,000 852,783 947,196 75,955 19,000 1,402 3,616 6,996 840 1,553,366 1,116,000 1,033,058 1,135,072 95,022 36,000 7,410 12,144 15,004 850 1,755,293 1,318,000 1,226,231 1,335,932 116,019 57,000 19,791 26,773 28,005 0 860 1,970,223 1,533,000 1,433,023 1,550,413 139,016 80,000 37,072 46,470 46,005 1,000 3 1,000 870 2,197,965 1,760,000 1,652,515 1,777,392 164,072 105,000 58,466 70,336 68,030 5,000 22 2,001 880 2,438,182 2,000,000 1,883,848 2,017,082 191,093 132,000 83,106 97,224 92,045 15,000 3 333 5,002 

890 2,690,951 2,253,000 2,126,659 2,269,693 220,078 161,000 110,331 126,508 120,042 31,000 613 1,598 9,003 

900 2,955,871 2,518,000 2,382,025 2,534,660 251,074 192,000 139,931 158,037 150,044 53,000 3,923 5,881 15,004 1,000 910 3,235,215 2,797,000 2,651,111 2,813,466 285,107 226,000 171,729 191,831 182,068 79,000 13,327 15,282 21,008 3,001 920 3,530,167 3,092,000 2,935,024 3,107,545 321,106 262,000 205,629 227,998 215,071 108,000 28,477 29,931 29,010 6,002 

930 3,837,980 3,400,000 3,234,794 3,416,642 360,092 301,000 241,638 266,551 251,064 141,000 47,200 48,947 38,010 11,003 

940 4,162,159 3,724,000 3,549,390 3,740,523 401,112 342,000 279,827 307,479 291,081 178,000 69,753 72,031 47,013 16,004 

950 4,499,216 4,061,000 3,877,572 4,078,495 445,120 386,000 320,665 350,922 332,090 218,000 96,799 99,254 57,015 22,006 

960 4,851,683 4,414,000 4,220,395 4,430,670 491,069 432,000 364,387 397,248 375,053 261,000 127,863 130,407 67,009 1,000 29,004 970 5,218,366 4,781,000 4,577,565 4,797,271 540,038 481,000 410,912 446,359 419,029 305,000 162,558 165,308 79,006 3,000 36,003 980 5,599,644 5,161,000 4,948,799 5,178,216 591,174 532,000 459,917 498,102 467,137 353,000 200,814 203,818 91,027 7,000 44,013 990 5,994,466 5,557,000 5,334,186 5,573,694 647,050 588,000 511,418 552,928 516,040 402,000 242,534 246,592 104,008 14,000 52,004 

1000 6,406,257 5,968,000 5,734,763 5,983,994 705,138 646,000 565,916 610,967 567,111 453,000 287,541 293,360 118,023 24,000 61,012 

1010 6,833,105 6,395,000 6,152,535 6,410,464 766,124 707,000 624,023 672,417 621,100 507,000 336,159 343,044 132,021 36,000 71,011 

1020 7,277,108 6,338,000 6,587,004 6,853,602 830,241 771,000 685,763 736,856 678,196 564,000 388,598 396,018 148,043 51,000 2 81,023 

1030 7,736,628 7,298,000 7,037,820 7,313,398 899,189 840,000 750,955 804,067 736,155 622,000 444,241 452,234 166,035 69,000 402 91,019 1

1040 8,213,743 7,775,000 7,505,226 7,790,156 969,206 910,000 819,825 874,449 797,169 683,000 502,594 511,175 184,039 87,000 1,582 103,022 3,000 1

1050 8,705,997 8,267,000 7,989,441 8,283,536 1,043,239 984,000 892,160 948,037 861,198 747,000 564,040 573,111 204,047 107,000 3,784 117,027 9,000 1

1060 9,215,849 8,777,000 8,491,653 8,793,439 1,121,225 1,062,000 968,214 1,025,144 928,186 814,000 628,829 638,350 224,045 127,000 7,064 131,026 16,000 1

1070 9,740,756 9,302,000 9,018,219 9,319,801 1,202,217 1,143,000 1,049,252 1,105,902 998,180 884,000 697,282 706,882 247,045 150,000 1,162 0 146,026 27,000 11080 10,282,980 9,844,000 9,544,624 9,862,788 1,288,248 1,229,000 1,132,296 1,190,233 1,069,206 955,000 767,260 778,269 271,052 174,000 16,600 41 163,031 40,000 21090 10,842,509 10,404,000 10,095,815 10,423,264 1,377,192 1,318,000 1,220,070 1,278,080 1,144,159 1,030,000 840,586 852,775 296,041 199,000 23,463 371 181,025 54,000 21100 11,419,299 10,981,000 10,664,746 11,001,398 1,470,167 1,411,000 1,312,151 1,369,820 1,222,139 1,108,000 917,103 930,750 323,037 226,000 31,226 1,138 200,023 70,000 21110 12,014,564 11,576,000 11,251,489 11,597,491 1,567,204 1,508,000 1,408,990 1,465,840 1,303,170 1,189,000 997,000 1,011,919 352,046 255,000 40,534 2,661 222,029 88,000 2

1120 12,626,992 12,188,000 11,854,039 12,211,986 1,669,263 1,610,000 1,510,767 1,565,672 1,387,219 1,273,000 1,079,892 1,095,993 383,060 286,000 53,019 6,063 244,039 107,000 31130 13,257,498 12,819,000 12,472,062 12,844,541 1,775,201 1,716,000 1,617,266 1,669,155 1,474,167 1,360,000 1,165,461 1,182,910 415,047 318,000 73,216 11,450 268,030 129,000 31140 13,905,795 13,467,000 13,106,619 13,494,717 1,885,243 1,826,000 1,727,956 1,776,190 1,564,202 1,450,000 1,253,848 1,272,636 450,058 353,000 101,770 21,140 293,038 152,000 3

1150 14,571,311 14,132,000 13,761,553 14,163,314 1,999,317 1,940,000 1,843,322 1,886,876 1,656,263 1,542,000 1,345,955 1,365,235 488,077 391,000 134,746 40,096 319,051 177,000 4

1160 15,256,694 14,872,000 14,445,823 14,851,758 2,116,374 2,057,000 1,963,857 2,001,376 1,752,309 1,638,000 1,442,077 1,460,872 527,093 430,000 172,461 67,310 349,062 205,000 652 4

1170 15,961,763 15,522,000 15,149,340 15,560,503 2,239,388 2,180,000 2,087,846 2,119,221 1,851,320 1,737,000 1,540,446 1,559,214 570,099 473,000 214,479 99,144 378,065 234,000 21,992 4

1180 16,688,812 16,248,000 15,872,538 16,289,961 2,365,540 2,306,000 2,215,790 2,240,409 1,951,446 1,837,000 1,641,248 1,660,047 613,140 516,000 258,808 137,002 411,094 267,000 54,078 0 5

1190 17,432,724 16,995,000 16,615,865 17,040,320 2,495,104 2,436,000 2,348,127 2,365,313 2,055,085 1,941,000 1,744,566 1,763,442 660,027 563,000 305,162 181,480 445,018 301,000 88,548 12,995 5

1200 18,197,534 17,760,000 17,379,212 17,811,666 2,630,077 2,571,000 2,484,998 2,494,060 2,161,063 2,047,000 1,850,547 1,869,569 708,021 611,000 353,708 229,661 481,014 337,000 124,761 48,502 61210 18,984,407 18,547,000 18,165,052 18,606,224 2,769,059 2,710,000 2,626,564 2,626,800 2,270,049 2,156,000 1,959,459 1,978,728 758,016 661,000 404,777 280,251 519,011 375,000 162,686 94,481 6

1220 19,796,616 19,360,000 18,974,393 19,424,820 2,911,944 2,853,000 2,772,075 2,762,960 2,380,954 2,267,000 2,070,959 2,090,700 811,984 715,000 458,309 333,200 557,989 414,000 202,404 142,330 7

1230 20,630,536 20,195,000 19,806,002 20,266,660 3,058,783 3,000,000 2,921,521 2,902,552 2,494,823 2,381,000 2,184,907 2,205,417 866,938 770,000 514,246 388,473 599,957 456,000 244,127 192,146 7

 
2001 Lake Mead Sedimentation Survey 

98
99

References 

American Society of Civil Engineers, 1962. Nomenclature for Hydraulics, ASCE 

Headquarters, New York. 

ASTM, 2008. Annual Book of Standards, Section 11, Volumes 11.01 and 11.02, 

ASTM, West Conshohocken, PA. 

Blanton, J.O. III, 1982. Procedures for Monitoring Reservoir Sedimentation: 

Technical Guideline for Bureau of Reclamation, Denver, CO. 

Brown, C., July 1941. Mapping Lake Mead, U.S. Soil Conservation Service 

Bureau of Reclamation, 2001. The Boulder Canyon Project Hoover Dam,

Lower Colorado Regional Office, Boulder City, NV. 

Bureau of Reclamation, 1981. Project Data, Denver Office, Denver CO. 

Bureau of Reclamation, 1985. Surface Water Branch, ACAP85 User's Manual, 

Technical Service Center, Denver CO. 

Bureau of Reclamation, 1987(a). Guide for Preparation of Standing Operating 

Procedures for Bureau of Reclamation Dams and Reservoirs, U.S. Government 

Printing Office, Denver, CO. 

Bureau of Reclamation, 1987(b). Design of Small Dams, U.S. Government 

Printing Office, Denver CO. 

B29, In Depth Consulting, 2002. 

http://www.indepthconsulting.com/B29/B29Lost.htm

Clarke Hughes, J. E., (2005) Lake Powell Multibeam Mapping 2005, University 

of New Brunswick, Canada. 

Corps of Engineers, April 2004. Engineer and Design - Hydrographic Surveying, 

EM 1110-2-1003, Department of the Army, Washington DC, 

(www.usace.army.mil/inet/usace-docs/eng-manuals/). 

Covay, K. and Beck, D., 2001. Sediment-Deposition Rates and Organic 

Compounds in Bottom Sediment at Four Sites in Lake Mead in May 1998,

Open-File Report 01-282, U.S. Geological Survey. 

Dettinger, M.D. (1995). Coping With Severe and Sustained Drought in 

Southwest, U.S. Geological Survey. 
2001 Lake Mead Sedimentation Survey 

100

Environmental Systems Research Institute, Inc. (ESRI). (1992). ARC Command 

References. 

Ferrari, R.L. (1988). “1986 Lake Powell Survey,” REC-ERC-88-6. Bureau of 

Reclamation, Sedimentation and River Hydraulics Group. Denver, Colorado. 

Ferrari, R.L. (2003). Deadwood Reservoir 2002 Survey, Bureau of Reclamation, 

Sedimentation and River Hydraulics Group. Denver, Colorado. 

Ferrari, R.L. (2006). Reconnaissance Techniques for Reservoir Survey, Bureau 

of Reclamation, Sedimentation and River Hydraulics Group. Denver, Colorado. 

www.usbr.gov/pmts/sediment 

Ferrari, R.L. and Collins, K. (2006). Reservoir Survey and Data Analysis, 

Chapter 9, Erosion and Sedimentation Manual, Bureau of Reclamation, 

Sedimentation and River Hydraulics Group. Denver, Colorado. 

www.usbr.gov/pmts/sediment 

Goodson and Associates, Inc., 1981. Technical Data Workbook Abstract Report 

for Hoover Dam Boulder Canyon Project Arizona-Nevada. Lower Colorado 

Region. Aurora, Colorado. 

Grove, N.C., and Howard, C.S. 1938, The Passage of Turbid Water Through 

Lake Mead. American Society Civil Engineer transcripts, Volume 103, page 720 

– 790. 

HYPACK, Inc. (2005). HYPACK for Windows, (www.hypack.com). 

Hilldale, R.C. (2004). Collection of River Bathymetry in Shallow Water 

Conditions Using Airborne LiDAR, Bureau of Reclamation, Sedimentation and 

River Hydraulics Group. Denver, Colorado. 

International Hydrographic Organization, IHO (May 2005). Manual on 

Hydrography, M-13. www.iho.shom.fr. 

Lara, J. M. and Sanders, J. I. (1970). The 1963-64 Lake Mead Survey, Bureau of 

Reclamation, Sedimentation and River Hydraulics Group. Denver, Colorado. 

Lara, J. M. and Pemberton, E. L. (1965). Initial Unit Weight of Deposited 

Sediments, Reservoir Sedimentation Technical Guideline for Bureau of 

Reclamation, Sedimentation and River Hydraulics Group. Denver, Colorado. 

Lin, S.S. (1997). Strategies for Management of Reservoir Sedimentation. 

Virginia Dam Safety Program, Richmond, Virginia. 
101

Lower Colorado Regional (LCR) Office, 2003. The 2001 Lake Mead 

Bathymetry Study, Bureau of Reclamation, Lower Colorado Regional Office, 

Boulder City, NV. 

Lyons, J. and Lest, L. (1996). Theodore Roosevelt Reservoir, Bureau of 

Reclamation. Sedimentation and River Hydraulics Group. Denver, Colorado. 

Miller, C. R. (1953). “Determination of the Unit Weight of Sediment for Use in 

Sediment Volume Computations,” Bureau of Reclamation, Denver, Colorado. 

Morris, G. L. and Fan, J. (1997). Reservoir Sedimentation Handbook, Gregory 

L. Morris and Assoc. San Juan, Puerto Rico and Institute of Water Conservancy, 

Beijing, China. 

Pratson, Lincoln (2007). Effects of Subaqueous Gravity Flows on Timing and 

Patterns of Basin Infilling as Documented in Lake Powell During a Drought, 

Professor of Sedimentary Geology Earth & Ocean Sciences, Duke University, 

Durham, NC. (2/2008 currently under review for publication). 

SCS (Soil Conservation Service) (May 1940). Original Area and Capacity Table 

for Lake Mead, Washington D.C. 

Sedimentation Group (2006), Erosion and Sedimentation Manual,

(Sedimentation Manual), U.S. Bureau of Reclamation, Sedimentation and River 

Hydraulics Group, Denver, Colorado. 

Strand, R.I., and E.L. Pemberton. (October 1982). Reservoir Sedimentation, 

U.S. Bureau of Reclamation, Sedimentation and River Hydraulics Group, Denver, 

Colorado. 

Twichell D. C., Cross, V.A., Rudin M. J. and Parolski, K.F. (1999). Surficial 

Geology and Distribution of Post-Impoundment Sediment of the Western 

Park of Lake Mead Based on a Sidescan Sonar and High-Resolution SeismicReflection Survey, Open-File Report 99-581, University of Nevada at Las Vegas 

and U.S. Geological Survey. 

Twichell, D.C., Cross, V.A., and Belew, S.D. (2003). Mapping the floor of 

Lake Mead (Nevada and Arizona): Preliminary discussion and GIS data release: 

USGS Open-File Report 03-320, 1 CD-ROM. 

USGS. (1960). Comprehensive Survey of Sedimentation in Lake Mead, 1948-49. 

Geological Survey Professional Paper 295. 

 

USGS (2001). Water Resources Data Arizona Water Year 2001, Water-Data 

Report Arizona 2001, U.S. Geological Survey, Phoenix, AR. 
2001 Lake Mead Sedimentation Survey 

102
Appendix I 
2001 Lake Mead Sedimentation Survey 

104
Basins by Map Numbers 

As part of the 1963 analysis, Lake Mead was divided into basins, figure 29. The 

basins were outlined along the boundaries of maps covering the entire reservoir, 

figure 29. 

Figure 29 - Lake Mead divided by subbasins, LCR 2003 report. 
2001 Lake Mead Sedimentation Survey 

106

Figure 30 - Lake Mead divided by submaps, LCR 2003 report. 

Following are the map numbers that are within the listed basins, some of the listed 

basins were combined as part of the final analysis: 

Boulder and Virgin Basin 

Subbasins - Areas 1, x, y, and 2 

Maps 123, 4, 5, 6-7, 8, 9, 10, 11-12, 19, 20-21, 28, 27, 18, and 26 

Temple Bar and Virgin Canyon 

Subbasins - Areas 3a and 3b 

Maps 34, 35, and 36 

Gregg Basin 

Subbasin - Area 4 

Maps 37, 38, and 41 
107

Grand Bay 

Subbasin - Area 5 

Maps 40, 42, and 39 

Pierce Basin 

Subbasin - Area 6 

Map 43 

Lower Granite Gorge 

Subbasin - Area 7 

Maps 44 through 52 

Overton Arm 

Subbasins - Areas 8a and 8b 

Maps 14, 15, 16, 17, 22, 23, 24, 25, 30, 31, 32, and 33 
2001 Lake Mead Sedimentation Survey 

108
Appendix II 
2001 Lake Mead Sedimentation Survey 

110
111

Depth Measurements 

Calibration and checks 

During field collection daily velocity profile readings of reservoir were conducted 

along with limited bar checks. The velocity profiles were collected with a digital 

meter with attached probe on 100 meters of power cable. For the lake zone below 

100 meters of depth, the speed of sound was extrapolated. 

During analysis of the bottom data, concerns arose about the depth measurements 

from Hoover Dam upstream to the Temple Bar area because the final elevations 

from the 2001 analysis were found to be lower than the 1963 study. Multiple 

checks were performed to confirm the resulting elevations: 

1. Contacted Reclamation’s Ecological Research and Investigations Group of the 

TSC concerning their collection on Lake Mead. 

Received several files with depth information. 

All data in WGS84, converted to conform to 2001 Sedimentation data. 

a. Collection date: 1/17/01 

Lake elevation 1,196.15 = 364.6m 

 =114.6 m (measured depth) 

 elevation 250 meters 

 

 Location

 36.0917546 North 3,996,391 

(-)114.7873464 East 699,205 

Located in Vegas Wash

Plot on 2001 ARC Maps ***** elevations match***********

b. Collection data: 1/17/01 

Lake elevation = 364.6 

 143.7 (measured depths) 

bottom elevation 220.9 meters 
2001 Lake Mead Sedimentation Survey 

112

 Location

 36.0611852 N 3,993,098 

(-)114.7402076 E 703,528 

Upstream of Sentinel Island ************ Good Check*************

Additional data was checked from 2/01 collection, also with good results. 

2. Bar checks 

 Single Beam Data

Single beam data was collected with a digital sounder calibrated by a standard bar 

check. Data was collected from the upper Overton Arm downstream to the 

confluence of the Colorado River. In flat areas of the reservoir bottom, there were 

good checks throughout the whole reach. 

3. Elevations at base of the intake towers located upstream of Hoover Dam and 

top of cofferdam. 

a. Base of intake tower on drawing file, elevation 894 feet. The 

processed multibeam data measured the base of the intake tower 

around elevation 894. (Good check). 

b. Top of cofferdam on drawing around elevation 720 feet. The 

processed multibeam data measured the top of cofferdam near 

elevation 735. Limited research into the cofferdam did not find 

detailed information on the cofferdams. Some of this is listed within 

this report such as comments about concerns of overtopping during 

construction, possible the top of cofferdam was raised higher then 

listed on drawings. 
Appendix III
2001 Lake Mead Sedimentation Survey 

114
115

Lake Mead Cross Sections

Cross sections were cut through the original (1935) and 2001 Lake Mead 

topography throughout the reservoir, figure 30. The LCR GIS group developed 

the cross sections using ARCGIS tools, locating some near cross sections shown 

in the 1963 report. 

Figure 31 - Location of Lake Mead cross sections 
2001 Lake Mead Sedimentation Survey 

116

Section G-G'

850

900

950

1000

1050

1100

200.00 400.00 600.00 800.00 1000.00 1200.00 1400.00 1600.00

Distance In Feet

Elevation in Feet

1935 Elevation 1948-49 1963-64 2001 Elevation

Figure 32 - Gregg Basin section G-G 

Section H-H'

800

820

840

860

880

900

920

940

960

980

1000

4000 5000 6000 7000 8000 9000 10000

Distance in Feet

Elevation in Feet

1935 Elevations 1948-49 1963-64 2001 Elevations

Figure 33 - Gregg Basin section H-H 
117

Section I-I'

750

800

850

900

950

500 1000 1500 2000 2500

Distance in Feet

Elevation in Feet

1935 Elevations 1948-49 1963-64 2001 Elevations

Figure 34- Temple Bar section I-I 

Section J-J'

750

770

790

810

830

850

870

890

4000 5000 6000 7000 8000

Distance in Feet

Elevation in Feet

1935 Elevations 1948-49 1963-64 2001 Elevations

Figure 35 - Temple Bar section J-J 
2001 Lake Mead Sedimentation Survey 

118

Section K-K'

700

720

740

760

780

800

820

840

5000 7000 9000 11000 13000 15000

Distance in Feet

Elevation in Feet

1935 Elevations 1948-49 1963-64 2001 Elevations

Figure 36 - Virgin Basin section K-K 

Section L-L'

650

670

690

710

730

750

770

790

810

830

850

100 300 500 700 900 1100 1300 1500

Distance in Feet

Elevation in Feet

1935 Elevations 1948-49 1963-64 2001 Elevations

Figure 37 - Boulder Canyon section L-L. 
119

Section M-M'

600

650

700

750

800

850

900

950

19000 19500 20000 20500 21000 21500 22000 22500 23000 23500 24000

Distance in Feet

Elevation in Feet

1935 Elevations 1948-49 1963-64 2001 Elevations

Figure 38 - Boulder Basin, section M-M 

Section N-N'

600

700

800

900

1000

1100

1200

1300

0 200 400 600 800 1000 1200 1400

Distance in Feet

Elevation in Feet

1935 Elevations 2001 Elevations 1948-49 1963-64

Figure 39 - Boulder Basin near dam, section N-N. 1963 survey plotted below 1948. 
2001 Lake Mead Sedimentation Survey 

120

Section Q-Q'

1100

1150

1200

200 400 600 800 1000 1200

Distance in Feet

Elevation in Feet

1935 Elevations 2001 Elevations

Figure 40 - Overton Arm, section Q-Q 

Section R-R'

1050

1070

1090

1110

1130

1150

500 1500 2500 3500 4500 5500 6500

Distance in Feet

Elevation in Feet

1935 Elevations 1948-49 1963-64 2001 Elevations

Figure 41 - Overton Arm, section R-R. 
121

Section S-S'

950

970

990

1010

1030

1050

1070

1090

1110

1130

1150

0 2000 4000 6000 8000 10000

Distance in Feet

Elevation in Feet

1935 Elevations 1963-64 2001 Elevations

Figure 42- Overton Arm, section S-S. 

Section T-T'

900

950

1000

1050

1100

1150

3000 5000 7000 9000 11000 13000 15000

Distance in Feet

Elevation in Feet

1935 Elevations 1963-64 2001 Elevations

Figure 43 - Overton Arm, section T-T. 
2001 Lake Mead Sedimentation Survey 

122

Section U-U'

900

920

940

960

980

1000

1020

1040

1060

1080

1100

6000 8000 10000 12000 14000 16000 18000 20000

Distance in Feet

Elevation in Feet

1935 Elevations 1963-64 2001 Elevations

Figure 44 - Overton Arm, section U-U. 

Section 1112

600

700

800

900

3000 4000 5000 6000 7000 8000 9000 10000

Distance in Feet

Elevation in Feet

1935 Elevations 2001 Elevations

Figure 45 - Section 1112. 
123

Section 67

600

650

700

750

800

850

900

950

1000

4000 5000 6000 7000 8000 9000 10000

Distance in Feet

Elevation in Feet

1935 Elevations 2001 Elevations

Figure 46 - Section 67. 

Section 19

600

650

700

750

800

850

900

950

1000

5000 6000 7000 8000 9000 10000 11000 12000

Distance in Feet

Elevation in Feet

1935 Elevations 2001 Elevations

Figure 47 - Section 19. 
2001 Lake Mead Sedimentation Survey 

124

Section 27

600

650

700

750

800

850

900

950

1000

5000 5500 6000 6500 7000 7500 8000

Distance in Feet

Elevation in Feet

1935 Elevations 2001 Elevations

Figure 48 - Section 27. 

Section 26

600

650

700

750

800

850

900

950

1000

5000 7000 9000 11000 13000 15000

Distance in Feet

Elevation in Feet

1935 Elevations 2001 Elevations

Figure 49 - Section 26. 
125

Section 25

800

820

840

860

880

900

920

940

960

980

1000

3000 3500 4000 4500 5000 5500 6000

Distance in Feet

Elevation in Feet

1935 Elevations 2001 Elevations

Figure 50 - Section 25. 

Section 37

800

820

840

860

880

900

920

940

960

980

1000

500 1000 1500 2000 2500 3000 3500

Distance in Feet

Elevation in Feet

1935 Elevations 2001 Elevations

Figure 51 - Section 37. 
2001 Lake Mead Sedimentation Survey 

126
Appendix IV 
2001 Lake Mead Sedimentation Survey 

128
129

Reservoir Sediment Compaction Analysis 

The following compaction analysis and computations refer to the Reclamation 

report “Reservoir Sedimentation” authored by Mr. Robert Strand and Mr. Ernie 

Pemberton. A literature search was conducted by internet, but information on 

reservoir compaction was limited. 

Previous surveys on Lake Mead included extensive sediment sampling programs, 

focused primarily in the upper reservoir area. The upper delta experienced 

limited compaction because the majority of material deposited consists of higher 

density sediment, not the fines that drift further downstream towards the dam. 

The initial porosity of the sediment deposited downstream is greater than the 

initial porosity of the upstream deposits. Also, the upper delta has been 

dewatered and partially dried out during reservoir drawdown. Subsequent 

inflowing sediment deposits on the delta as the river transport capacity geometry 

allows (Strand and Pemberton, 1982). 

Compaction analysis 

Reservoir operation has most influence in determining compaction of the 

deposited sediments. There are four operations to consider: 

 1 – Sediment always submerged or nearly submerged 

 2 – Normally moderate to considerable reservoir drawdown 

 3 – Reservoir normally empty 

 4 – Riverbed sediments 

Analyzing the annual reservoir operation, since initial filling the Lake Mead, the 

sediments in question are classified as number 1 (always submerged). 

The following equations were used to estimate the density of the sediment 

deposits. 

 W = Wcpc + Wmpm +Ws + ps 

 Where: 

 W = unit weight in pounds in cubic feet 

 pc, pm, ps = percentages of clay, silt, and sand, respectively, of the 

 incoming sediment 

 Wc, Wm, Ws = coefficients of clay, silt, and sand, respectively that is 

 obtain from the reference 

For a classified reservoir operation of 1 
2001 Lake Mead Sedimentation Survey 

130

Wc = 26 (initial weight in lb/ft3) 

Wm = 70 (initial weight in lb/ft3

) 

Ws = 97 (initial weight in lb/ft3) 

From 1963 study the reported sampling was: 

Clay = 60% 

Silt = 28% 

Sand = 12% 

W = 26(.60) + 70 (.28) + 97 (.12) = 46.84 

In determining density of sediment deposits in reservoirs over time of reservoir 

operation, it is recognized that portions of the sediment will deposit over each 

operation year “T” and each year’s deposits will have a different compaction 

time. Miller (1953), developed an approximation of the integral for determining 

the average density of all sediment deposited in “T” years of operation as: 

 WT = W1 + 0.4343K [ T / (T-1) (logeT)-1] 

 Where: 

 

WT = average density after “T” years of reservoir operation 

W1 = initial unit weight (density) as derived from first equation 

 K = constant based on type of reservoir operation and sediment 

size analysis as obtained from table for different reservoir 

operations

For reservoir operation number 1

 K (sand) = 0 inch-pound 

 K (silt) = 5.7 inch-pound 

 K (clay) = 16 inch-pound 

 K = 16(0.60) + 5.7(.28) + (0)(.12) = 11.196 

For 66 years of Lake Mead operations since closure: 

 W66 = 46.84 + 0.434 (11.196) [66 / (66-1) (4.19) -1] 

= 46.84 + (4.86) (3.25) 

= 62.63 lb/ft3

Assumed some sediment deposition occurred at dam during construction and 

initial filling. Since 1963, 38 years of operation with sediments submerged. 
131

W38 = 46.84 +0.4343(11.196) [ 38 / (38-1) (3.64)-1] 

 = 46.84 + 4.86(2.74) 

= 60.15 lb/ft3

After 13 years of operations (1935 – 1948)

W13 = 46.84 + 0.4343 (11.196) [13 / (13 – 1) (loge (12)-1] 

 = 53.6 

From 1948 – 64

W16 = 53/6 + 0.4343(11.196) [16 / (16-1)(loge16)-1]

 =62.2 

After 37 years (1964-2001)

W37 = 62 + (0.4343)(11.196) [(37 / (37-1) loge(37) - 1]

 = 75 

From field survey results

1948 survey measured around 80 feet of sediment near dam 

1963 survey measured around 75 feet of sediment near dam 

For 1963 - (53.6/62.2)(80 feet) = 69 ft 

For 2001 - (62/75)(75 feet) = 62 feet 

Around 7 feet of consolidation from equations. The 2001 survey measured about 

10 feet of consolidation. Must be noted that after closure of Glen Canyon Dam in 

1963 a large source of previous sediment inflow was cut off. 
2001 Lake Mead Sedimentation Survey 

132
Appendix V 
2001 Lake Mead Sedimentation Survey 

134
135

Summary of Analysis by TSC 

Following is a summary of surface area computations conducted by the 

Sedimentation Group in September of 2002. The process was conducted, map by 

map, with the approach of looking for change from the original measured surface 

areas due to sediment deposition. When the 2001 data indicated no change due to 

sediment, at the 10-foot contour interval, the contour was marked as no change 

and the original surface area listed in the 1963 report was used. 

Using ARC tools, version 8.1.2, developed TIN coverages and resulting contours 

by the LCR were used for this analysis. The initial Sedimentation analysis 

determined the DEM developed TIN’s, contours, and resulting surface areas did 

not provide sufficient detail, mainly for lower elevations and small coves, to 

match the original map detail and resulting surface areas. In most cases however, 

the surface areas were very close to the original published surface areas (within 2 

percent). 

The Sedimentation Group took the approach that the original surface areas by 

map at the 10-foot contour intervals were correct. Even though the GIS computed 

surface areas using the DEM data are very close, there is a difference that is 

attributed more to the limited detail of the DEM data rather than errors in the 

original measured data. Another issue was that the DEM original data was not 

available for all the maps that cover Lake Mead. This included the maps from the 

Pierce Ferry area upstream. Since these areas of Lake Mead contain available 

capacity not completely lost due to sediment deposition, an approach was taken to 

estimate the available capacity in these areas and the total sediment deposition 

within Lake Mead. 

The previous studies, 1948 and 1963, used the original maps and surface areas as 

the initial base for measuring change. The Sedimentation Group used the same 

approach for the 2001 analysis. Following information was used for the 

Sedimentation Group’s map analysis. 

1. The 2001 LiDAR data, when combined with the multibeam and single 

beam data and the previously collected Biological cross sections, provided 

enough detailed coverage of maps 40, 42, and 43 for estimating change 

since the original topography was measured. Some interpretation was 

required and the vertical elevations of the LiDAR data were adjusted to 

match the Lake Mead vertical datum. 

2. The analysis refers to results from the 1963 reservoir survey that included 

only the thalweg and a few cross section plots. The 2001 survey results 

indicate there were only minor changes in the reach above Pierce Ferry 

since the 1963 and the 1948 studies. There is around 30 miles of reservoir 
2001 Lake Mead Sedimentation Survey 

136

length and volume that is small compared to rest of the reservoir, but this 

analysis estimated the available capacity of this portion of the reservoir. 

The following analysis is listed by map and was conducted by Ron Ferrari of the 

Sedimentation Group. When the 2001 multibeam survey data provided enough 

detail for the contour elevation being measured, the GIS computed surface area 

was used. When 2001 data was not available or when the information indicated 

little to no change due to sediment deposition, the original surface area was used. 

For maps that covered areas such as Las Vegas Wash and the Overton Arm, the 

survey and analysis mainly focused on the relatively small river channels. The 

remaining map areas were assumed to have no change due to sediment deposition. 

That assumption was supported by the 2001 survey and previous cross section 

surveys of the reservoir. The 2001 survey measured changes due to sediment 

deposition, mainly confined to original river channel areas. These 2001 river 

channel contours were digitized to measure the new surface areas. 

The final surface area analysis conducted in September of 2002 is summarized 

here. Previous analysis of the GIS developed maps in the spring of 2002 found 

that the map boundary was slightly off. This was corrected and forwarded to the 

Sedimentation Group in September 2002 allowing limited time for the analyses. 

1. The original map surface areas, as listed in the 1963 report, were used as 

the base for this analysis. 

a. When the original developed DEM contours were overlaid with the 

scanned original maps, the DEM developed maps did not show the 

detail in the narrow canyons and channels. Comparisons of the 

original and GIS computed surface areas were usually within 2 

percent. 

b. The Excel spread sheet containing the GIS developed original 

surface areas for maps 1 through 41, did not include values for 

map 30. At elevation 1,230 the original surface area was 152,233 

acres compared to a GIS computed surface area of 149,882 acres. 

For elevation 1,100 the original surface area was 92,702 acres 

compared to the GIS computed area of 91,574 acres. For elevation 

1,000 the original surface area was 58,090 acres compared to the 

GIS computed area of 57,728 acres. 

The general conclusion was the differences were due to the differences of detail 

between the two data sets, not errors from either of the analyses. The 10 meter 

DEM’s were developed by scanning the original maps and did not provide enough 

detail to match the original 5- and 10-foot map contours. 
137

NOTE: The difference in most cases was 2 percent or less which is 

considered very close. The main problem for the sediment analysis was that 

the original maps were not available for all of Lake Mead in a digital format. 

If all were available, a reliable sediment computation could be developed by 

comparing the GIS developed original and 2001 values. Even if all maps 

were available there would still be some question as to accuracy of the GIS 

computed surface area and resulting capacities. 

Map Analysis 

UTM Zone 11, NAD83 

During the analysis of the 1935 and 2001 GIS developed contours, judgments 

were made if no change had occurred. 

Map123 (Upper Vegas Wash) 

Note: Computations for this map was computed by digitizing areas to be 

removed (unless noted differently). GIS values of the total map 

were not used since the 2001 data only covered the main river 

channel with little overlap. 

Note: Elevation 1,180 was last contour developed with 2001 data due to 

low water surface during time of collection. Projected location of 

rest of contours assumes no change at elevation 1,230. 

Map 4 

Includes main channel and Las Vegas Wash. In main channel no change from 

elevation 750 and above. Changes in Las Vegas Wash starting at elevation 760. 

Use ARC 8.1 digitizing routines to measure changes in Vegas Wash. 

Note: Data collected in Government Wash, but doesn’t appear to develop 

good contours for doing comparisons and surface losses? 

Elevation 1,030 and above, NO CHANGE. 

Map 5 

From thalweg plot, little to no change from elevation 750 and above. 

No change elevation 760 and above. 

All changes from elevation 660 through 750 from GIS computations 
2001 Lake Mead Sedimentation Survey 

138

Map 6-7 

Includes Callville Bay, a plot of 2001 versus scan map shows some changes in the 

Callville Bay but too small to digitize. 

Changes in main channel only. 

No change for elevations 770 and above. 

Area from elevation 660 through 760 from GIS computations 

Map 8 

2001 GIS match well with elevation 750 and greater, no change for elevation 750 

and greater 

GIS computations for elevation 660 through 740 

Map 9 

Original map elevation 680 is the minimum. 

Original GIS map, elevation 670 with islands 

No change elevation 790 and above. 

Areas for elevations 660 through 780 from GIS computations 

Map 10 

NO CHANGE 

Map 11-12 

Elevation 760 and 770 end in map 

No change 790 and greater 

Areas for elevation 660 through 780 from GIS computations 

Map 14 

No change 

Map 15 

No change 
139

Map 16 

No change 

No 2001 data points 

Map 17 (Echo Bay) 

Note: not enough 2001 data to support showing changes elevation 1150 and 

greater 

No change elevation 1,080 and 1,090. 

Map 18 

Overton Mouth on south side 

2001 data is showing larger areas for contours 800 and above 

Assume no change elevation 800 and above 

Map 19 

Original map had contours for elevations 720, 730, and 740, but table only had 

elevation 740 and greater 

GIS of original only showed small area for 750. 

No change elevation 810 and above. Includes Bonelli Bay with upper contour 

being elevation 970. Comparison with scan original showed very little change in 

Bonelli Bay. 

Area changes from elevation 660 to 800 from GIS computations. 

Map 20 – 21 

Has Bonelli Bay, from plot of 2001 versus scan there appears to be little change in 

Bonelli Bay 

No Change 

Map 22 

2001 data is limited, but goes into map area 

Contour 1,180 crosses within map, some developed for elevation 1,150 through 

1,170 but 2001 data does not support it 

No change on muddy creek arm, limited 2001 data but indicates little change 

Virgin Arm digitized 
2001 Lake Mead Sedimentation Survey 

140

Map 23 

Digitized areas lost 

No change elevation 1,180 and above

Map 24 

Digitized areas lost 

Map 25 

Digitize loss assume change only in river channel upper portion of contours 

No change elevation 980 and above. 

Map 26 

No change elevation 880 and above 

Map 27 

Area start @ 740 in report and also in GIS 

Some of map area is in Overton Arm 

For 2001 coverage, small portion for elevation 800 and 810 

No change for elevation 820 and greater 

Map 27 

Portion of map in Overton Arm. GIS original only shows partial at elevation 750. 

Original maps shows complete contour. 

No change elevation 820 and above 

Area changes from elevation 660 through 810 from GIS computations

Map 28 

NO CHANGE 
141

Map 30 

No change, elevation 1230. All others zero (used thalweg plot to project) 

Map 31 

No change elevation 1230. All others losses digitized. 

Map 32 

No change elevation 1,180 and above. 

Changed areas digitized 

Map 33 

No change 

No 2001 points 

Map 34 

No change elevation 840 and greater 

GIS computed surface areas from elevation 830 and below 

Map 35 

Not able to detect changes in Temple tributary with 2001 data 

No change elevation 860 and greater 

Map 36 

No change 880 and greater 

Map 37 

GIS computed areas from elevation 1,040 and less 

No change elevation 1,050 and greater 
2001 Lake Mead Sedimentation Survey 

142

Map 38 

GIS computed areas from elevation 980 and less 

No change elevation 990 and greater 

Hualpai Wash on map, 2001 survey data 

Map 39 

From LiDAR, projected contour elevation 1,210 and 1,220 

Elevation 1,200 = zero area, no change elevation 1,230 

Map 40 

Developed GIS contours for elevations 1,080; 1,090; 1,100; 1,110; 1,120; 1,130; 

1,140; 1,150; and 1,160 

Assume no loss elevation 1,190 and higher 

Limited amount of underwater data in Grand Wash and very upper Colorado 

River. Will use computed losses from GIS, but also removed additional area in 

Upper Colorado Arm not covered by LiDAR using cross section data 

GIS computed areas for elevation 1,080 and greater with some digitized surfaces 

due to limited 2001 data 

Map 41 

Iceberg Canyon

Elevation 1,040 – 1,070 end on map, GIS computations 

No change elevation 1,090 and above 

Map 42 

No 2001 GIS computations 

No area, elevation 1,170 and less 

No change, elevation 1,190 and greater 

Elevation 1,180 ends within map, estimated location 

Map 43 

Portion mapped by LiDAR assumed no change in surface area elevation 1200 and 

above. 

Assume no area elevation 1180 and less 

Elevation 1,190 contour appears to have changes in upper end only, 
143

Note: Biological range lines located on map. Showed areas for elevation 1,180 

and even elevation 1,170. For elevation 1,190 the width = 375 feet 

Original width = 1,400 feet 

Cross sections show no change for elevation 1,200 and above 

River cross sections by Biological contract 

Cross section data started 3/18/99 

2001 cross section data is after lake level dropped 20 plus feet since 1999. Means 

some cross sections in river conditions and previous delta cut down in river 

change pushing sediments downstream. 

Initial Survey New Survey

Ao = Contour Area A1 = Contour Area (Computed) 

Wo' = Downstream Width W1′ = Downstream Width 

Wo′′ = Upstream Width W1′′ = Upstream Width 

 ( )

( )⎥

⎦

⎤ ⎢

⎣

⎡

+

+ = "

0

'

0

"

1

'

1

1 W W

W W A

Map 44 

No area elevation 1,170 and below 

No change elevation 1,210 and above 
2001 Lake Mead Sedimentation Survey 

144

Map 45 

Left bank delta height around 8 feet 

Right bank delta height around 6 feet 

No area elevation 1,170 and below 

Map 46 

No Area elevation 1,170 and below 

No change elevation 1,200 and above 

Map47 

No change elevation 1,200 and above 

No area elevation 1,180 and less 

Map 48 

No area elevation 1,180 and less 

No change elevation 1,200 and greater 

Map 49 

From field trip on 9/01, noted little delta on shore 

No change elevation 1,200 and greater 

No area elevation 1,180 and less 

Map 50 

1999 to 2001 cross section from Biological contract work 

1999 collected lake elevation around elevation 1,207. 

2001 collection near lake elevation of 1,185. 

No vertical control 

Cross sections about every 4 miles 

Use width adjustment method to adjust areas 

Map 51 (No areas) 

Map 52 (No areas) 
Appendix VI 
2001 Lake Mead Sedimentation Survey 

146

Boulder Canyon Project 

 Arizona - Nevada 

Lake Mead 

Area and Capacity Tables

U.S. Department of the Interior Bureau of Reclamation Technical Service Center Denver, Colorado 
i

The tables for Lake Mead were generated by means of the area-capacity program ACAP, using the least 

squares method of curve fitting developed by the Bureau of Reclamation Technical Service Center. This 

program computes area at 1.0-, 0.1-, and 0.01-foot increments by linear interpolation between basic data 

contours. The respective capacities and capacity equations are than obtained by integration of the area 

equations. The initial capacity equation is tested over successive intervals to check whether it fits 

within an allowable error term. At the next interval beyond, a new capacity equation (integrated from 

the basic area equation over that interval) begins testing the fit until it too exceeds the error term. 

The capacity curve thus becomes a series of curves, each fitting a certain region of data. The final 

area equations are obtained by differentiation of the capacity equations. Capacity equations are of the 

form y = a1 + a2x +a3x2

 where y is capacity and x is the elevation above an elevation base. The capacity 

equation coefficients for the reservoir are shown below (ε = 0.000001). 

Lake Mead – Boulder City, Nevada 

2001 AREA-CAPACITY TABLES 

EQUATION ELEVATION CAPACITY COEFFICIENT COEFFICIENT COEFFICIENT 

 NUMBER BASE BASE A1(INTERCEPT) A2(1ST TERM ) A3(2ND TERM)

 1 689.00 0 .0000 .0000 .0214 

 2 700.00 2 2.5850 .4700 .1735 

 3 710.00 24 24.6350 3.9400 2.4965 

 4 720.00 313 313.6850 53.8700 64.8055 

 5 730.00 7332 7332.9351 1349.9799 90.6185 

 6 740.00 29894 29894.5856 3162.3502 80.9200 

 7 750.00 69610 69610.0856 4780.7504 60.1965 

 8 760.00 123437 123437.2352 5984.6798 46.1830 

 9 770.00 187902 187902.3430 6908.3402 65.7410 

 10 780.00 263559 263559.8441 8223.1596 72.0570 

 11 790.00 352997 352997.1530 9664.3015 180.0733 

 12 800.00 467647 467647.5054 13265.7664 98.4393 

 13 810.00 610149 610149.1243 15234.5496 92.6296 

 14 820.00 771757 771757.5513 17087.1446 81.8251 

 15 830.00 950811 950811.5023 18723.6476 91.6823 

 16 840.00 1147216 1147216.2444 20557.2881 99.1583 

 17 850.00 1362705 1362704.9997 22540.4477 87.7673 

 18 860.00 1596886 1596886.2471 24295.7913 79.0589 

 19 870.00 1847750 1847749.9932 25876.9750 81.3110 

 20 880.00 2114650 2114650.7579 27503.1967 84.4095 

 21 890.00 2398123 2398123.7567 29191.3923 98.0515 

 22 900.00 2699842 2699842.7347 31152.4384 120.6118 

 23 910.00 3023428 3023428.2471 33564.6823 117.8746 

 24 920.00 3370862 3370862.4578 35922.1949 114.0576 

 25 930.00 3741490 3741490.2490 38203.3648 116.1590 

 26 940.00 4135139 4135139.7336 40526.5637 117.1168 

 27 950.00 4552117 4552116.9987 42868.9264 129.6001 

 28 960.00 4993766 4993766.5250 45460.9585 119.2805 

 29 970.00 5460304 5460303.9549 47846.6107 133.9119 

 30 980.00 5952161 5952161.0500 50524.8367 149.6390 

 31 990.00 6472373 6472373.4856 53517.6081 142.8348 

 32 1000.00 7021833 7021833.0510 56374.2961 155.0589 

 33 1010.00 7601082 7601081.9688 59475.4651 152.8856 

 34 1020.00 8211125 8211124.9745 62533.2097 154.5183 

 35 1030.00 8851909 8851909.0491 65623.6358 160.5176 

 36 1040.00 9524197 9524197.0229 68833.9746 168.7013 

 37 1050.00 10229407 10229398.0206 72212.4885 180.9724 

 38 1070.00 11746028 11746027.8345 79446.8825 170.1110 

 39 1080.00 12557508 12557508.0923 82849.0959 175.4484 

 40 1090.00 13403544 13403543.9883 86358.0260 172.7990 

 41 1100.00 14284404 14284403.8536 89814.0504 202.3005 

 42 1110.00 15202774 15202763.0956 93865.5801 193.2496 

 43 1130.00 17157364 17157363.9512 101590.0839 211.7038 

 44 1140.00 18194436 18194436.3419 105823.9563 261.6056 

 45 1150.00 19278836 19278837.8807 111054.9756 231.3824 

 46 1170.00 21592492 21592491.9673 120311.1217 317.6273 

 47 1180.00 22827366 22827365.8649 126663.6832 444.5582 

 48 1190.00 24138458 24138458.0334 135554.8647 400.4211 

 49 1200.00 25534048 25534047.9970 143563.1981 367.8014 

 50 1210.00 27006460 27006459.9038 150919.2564 277.6681 

 51 1220.00 28543420 28543419.8791 156472.7638 337.5337 
2001 Lake Mead Sedimentation Survey 

ii

Lake Mead survey in spring 2001 used the contour method to obtain the basic data for these tables. The 

underwater portion of the reservoir was collected by standard surveying techniques using a global 

positioning system and multibeam sounder. The above-water portion was determined from limited aerial 

LiDAR and original reservoir topography. These surveys provided measured surface areas at 10-foot 

increments for the reservoir area. The underwater survey was run by personnel from the Sedimentation 

and River Hydraulics Group of the Technical Service Center and Lower Colorado Regional Office. 

Reduction of the data was completed by the Sedimentation Group and the Lower Colorado Regional Office. 

The analysis for developing the surface areas for the attach table development was completed by the 

Sedimentation Group in Denver, Colorado. All data for these tables are tied to the project vertical 

datum that is 0.55 feet less than NGVD29. 
iii

Index 

Area in acres at 0.1-foot intervals ......................................................Total capacity in acre-feet at 0.10-foot intervals .......................................

1

 2001 LAKE MEAD - BOULDER CITY, NEVADA (AC 2001 AREA-CAPACITY TABLES  THE AREA TABLE IS IN ACRES THE ELEVATION INCREMENT IS IN ONE TENTH  ELEV. FEET 0 .1 .2 .3 .4 .5 .6 .7  689 0. 0. 0. 0. 0. 0. 0. 0.  690 0. 0. 0. 0. 0. 0. 0. 0.  691 0. 0. 0. 0. 0. 0. 0. 0.  692 0. 0. 0. 0. 0. 0. 0. 0.  693 0. 0. 0. 0. 0. 0. 0. 0.  694 0. 0. 0. 0. 0. 0. 0. 0.  695 0. 0. 0. 0. 0. 0. 0. 0.  696 0. 0. 0. 0. 0. 0. 0. 0.  697 0. 0. 0. 0. 0. 0. 0. 0.  698 0. 0. 0. 0. 0. 0. 0. 0.  699 0. 0. 0. 0. 0. 0. 0. 0.  700 0. 1. 1. 1. 1. 1. 1. 1.  701 1. 1. 1. 1. 1. 1. 1. 1.  702 1. 1. 1. 1. 1. 1. 1. 1.  703 2. 2. 2. 2. 2. 2. 2. 2.  704 2. 2. 2. 2. 2. 2. 2. 2.  705 2. 2. 2. 2. 2. 2. 2. 2.  706 3. 3. 3. 3. 3. 3. 3. 3.  707 3. 3. 3. 3. 3. 3. 3. 3.  708 3. 3. 3. 3. 3. 3. 3. 3.  709 4. 4. 4. 4. 4. 4. 4. 4.  710 4. 4. 5. 5. 6. 6. 7. 7.  711 9. 9. 10. 10. 11. 11. 12. 12.  712 14. 14. 15. 15. 16. 16. 17. 17.  713 19. 19. 20. 20. 21. 21. 22. 22.  714 24. 24. 25. 25. 26. 26. 27. 27.  715 29. 29. 30. 30. 31. 31. 32. 32.  716 34. 34. 35. 35. 36. 36. 37. 37.  717 39. 39. 40. 40. 41. 41. 42. 42.  718 44. 44. 45. 45. 46. 46. 47. 47.  719 49. 49. 50. 50. 51. 51. 52. 52.  720 54. 67. 80. 93. 106. 119. 132. 145.  721 183. 196. 209. 222. 235. 248. 261. 274.  722 313. 326. 339. 352. 365. 378. 391. 404.  723 443. 456. 469. 482. 495. 508. 520. 533.  724 572. 585. 598. 611. 624. 637. 650. 663. 
2001 Lake Mead Sedimentation Survey 

2

 2001 LAKE MEAD - BOULDER CITY, NEVADA (A 2001 AREA-CAPACITY TABLES  THE AREA TABLE IS IN ACRES THE ELEVATION INCREMENT IS IN ONE TENTH  ELEV. FEET 0 .1 .2 .3 .4 .5 .6 .7  725 702. 715. 728. 741. 754. 767. 780. 793.  726 832. 844. 857. 870. 883. 896. 909. 922.  727 961. 974. 987. 1000. 1013. 1026. 1039. 1052.  728 1091. 1104. 1117. 1130. 1143. 1156. 1169. 1181.  729 1220. 1233. 1246. 1259. 1272. 1285. 1298. 1311.  730 1350. 1368. 1386. 1404. 1422. 1441. 1459. 1477.  731 1531. 1549. 1567. 1586. 1604. 1622. 1640. 1658.  732 1712. 1731. 1749. 1767. 1785. 1803. 1821. 1839.  733 1894. 1912. 1930. 1948. 1966. 1984. 2002. 2021.  734 2075. 2093. 2111. 2129. 2147. 2166. 2184. 2202.  735 2256. 2274. 2292. 2311. 2329. 2347. 2365. 2383.  736 2437. 2456. 2474. 2492. 2510. 2528. 2546. 2564.  737 2619. 2637. 2655. 2673. 2691. 2709. 2727. 2746.  738 2800. 2818. 2836. 2854. 2872. 2890. 2909. 2927.  739 2981. 2999. 3017. 3035. 3054. 3072. 3090. 3108.  740 3162. 3179. 3195. 3211. 3227. 3243. 3259. 3276.  741 3324. 3340. 3357. 3373. 3389. 3405. 3421. 3437.  742 3486. 3502. 3518. 3535. 3551. 3567. 3583. 3599.  743 3648. 3664. 3680. 3696. 3713. 3729. 3745. 3761.  744 3810. 3826. 3842. 3858. 3874. 3891. 3907. 3923.  745 3972. 3988. 4004. 4020. 4036. 4052. 4069. 4085.  746 4133. 4150. 4166. 4182. 4198. 4214. 4230. 4247.  747 4295. 4311. 4328. 4344. 4360. 4376. 4392. 4409.  748 4457. 4473. 4489. 4506. 4522. 4538. 4554. 4570.  749 4619. 4635. 4651. 4667. 4684. 4700. 4716. 4732.  750 4781. 4793. 4805. 4817. 4829. 4841. 4853. 4865.  751 4901. 4913. 4925. 4937. 4949. 4961. 4973. 4985.  752 5022. 5034. 5046. 5058. 5070. 5082. 5094. 5106.  753 5142. 5154. 5166. 5178. 5190. 5202. 5214. 5226.  754 5262. 5274. 5286. 5298. 5310. 5323. 5335. 5347.  755 5383. 5395. 5407. 5419. 5431. 5443. 5455. 5467.  756 5503. 5515. 5527. 5539. 5551. 5563. 5575. 5587.  757 5624. 5636. 5648. 5660. 5672. 5684. 5696. 5708.  758 5744. 5756. 5768. 5780. 5792. 5804. 5816. 5828.  759 5864. 5876. 5888. 5900. 5912. 5924. 5937. 5949.  760 5985. 5994. 6003. 6012. 6022. 6031. 6040. 6049.  761 6077. 6086. 6096. 6105. 6114. 6123. 6132. 6142.  762 6169. 6179. 6188. 6197. 6206. 6216. 6225. 6234.  763 6262. 6271. 6280. 6289. 6299. 6308. 6317. 6326.  764 6354. 6363. 6373. 6382. 6391. 6400. 6410. 6419. 
3

 2001 LAKE MEAD - BOULDER CITY, NEVADA ( 2001 AREA-CAPACITY TABLES  THE AREA TABLE IS IN ACRES THE ELEVATION INCREMENT IS IN ONE TENTH  ELEV. FEET 0 .1 .2 .3 .4 .5 .6 .7  765 6447. 6456. 6465. 6474. 6483. 6493. 6502. 6511.  766 6539. 6548. 6557. 6567. 6576. 6585. 6594. 6604.  767 6631. 6640. 6650. 6659. 6668. 6677. 6687. 6696.  768 6724. 6733. 6742. 6751. 6761. 6770. 6779. 6788.  769 6816. 6825. 6834. 6844. 6853. 6862. 6871. 6881.  770 6908. 6921. 6935. 6948. 6961. 6974. 6987. 7000.  771 7040. 7053. 7066. 7079. 7092. 7106. 7119. 7132.  772 7171. 7184. 7198. 7211. 7224. 7237. 7250. 7263.  773 7303. 7316. 7329. 7342. 7355. 7369. 7382. 7395.  774 7434. 7447. 7461. 7474. 7487. 7500. 7513. 7526.  775 7566. 7579. 7592. 7605. 7618. 7631. 7645. 7658.  776 7697. 7710. 7724. 7737. 7750. 7763. 7776. 7789.  777 7829. 7842. 7855. 7868. 7881. 7894. 7908. 7921.  778 7960. 7973. 7986. 8000. 8013. 8026. 8039. 8052.  779 8092. 8105. 8118. 8131. 8144. 8157. 8171. 8184.  780 8223. 8238. 8252. 8266. 8281. 8295. 8310. 8324.  781 8367. 8382. 8396. 8411. 8425. 8439. 8454. 8468.  782 8511. 8526. 8540. 8555. 8569. 8583. 8598. 8612.  783 8656. 8670. 8684. 8699. 8713. 8728. 8742. 8756.  784 8800. 8814. 8828. 8843. 8857. 8872. 8886. 8900.  785 8944. 8958. 8973. 8987. 9001. 9016. 9030. 9045.  786 9088. 9102. 9117. 9131. 9145. 9160. 9174. 9189.  787 9232. 9246. 9261. 9275. 9290. 9304. 9318. 9333.  788 9376. 9390. 9405. 9419. 9434. 9448. 9463. 9477.  789 9520. 9535. 9549. 9563. 9578. 9592. 9607. 9621.  790 9664. 9700. 9736. 9772. 9808. 9844. 9880. 9916.  791 10024. 10060. 10096. 10132. 10169. 10205. 10241. 10277. 1 792 10385. 10421. 10457. 10493. 10529. 10565. 10601. 10637. 1 793 10745. 10781. 10817. 10853. 10889. 10925. 10961. 10997. 1 794 11105. 11141. 11177. 11213. 11249. 11285. 11321. 11357. 1 795 11465. 11501. 11537. 11573. 11609. 11645. 11681. 11717. 1 796 11825. 11861. 11897. 11933. 11969. 12005. 12041. 12077. 1 797 12185. 12221. 12257. 12293. 12329. 12365. 12401. 12437. 1 798 12545. 12581. 12618. 12654. 12690. 12726. 12762. 12798. 1 799 12906. 12942. 12978. 13014. 13050. 13086. 13122. 13158. 1 800 13266. 13285. 13305. 13325. 13345. 13364. 13384. 13404. 1 801 13463. 13482. 13502. 13522. 13541. 13561. 13581. 13600. 1 802 13660. 13679. 13699. 13719. 13738. 13758. 13778. 13797. 1 803 13856. 13876. 13896. 13915. 13935. 13955. 13975. 13994. 1 804 14053. 14073. 14093. 14112. 14132. 14152. 14171. 14191. 1
2001 Lake Mead Sedimentation Survey 

4

 2001 LAKE MEAD - BOULDER CITY, NEVADA ( 2001 AREA-CAPACITY TABLES  THE AREA TABLE IS IN ACRES THE ELEVATION INCREMENT IS IN ONE TENTH  ELEV. FEET 0 .1 .2 .3 .4 .5 .6 .7  805 14250. 14270. 14290. 14309. 14329. 14349. 14368. 14388. 1 806 14447. 14467. 14486. 14506. 14526. 14545. 14565. 14585. 1 807 14644. 14664. 14683. 14703. 14723. 14742. 14762. 14782. 1 808 14841. 14860. 14880. 14900. 14920. 14939. 14959. 14979. 1 809 15038. 15057. 15077. 15097. 15116. 15136. 15156. 15175. 1 810 15235. 15253. 15272. 15290. 15309. 15327. 15346. 15364. 1 811 15420. 15438. 15457. 15475. 15494. 15512. 15531. 15549. 1 812 15605. 15624. 15642. 15661. 15679. 15698. 15716. 15735. 1 813 15790. 15809. 15827. 15846. 15864. 15883. 15901. 15920. 1 814 15976. 15994. 16013. 16031. 16050. 16068. 16087. 16105. 1 815 16161. 16179. 16198. 16216. 16235. 16253. 16272. 16291. 1 816 16346. 16365. 16383. 16402. 16420. 16439. 16457. 16476. 1 817 16531. 16550. 16568. 16587. 16605. 16624. 16643. 16661. 1 818 16717. 16735. 16754. 16772. 16791. 16809. 16828. 16846. 1 819 16902. 16920. 16939. 16957. 16976. 16995. 17013. 17032. 1 820 17087. 17104. 17120. 17136. 17153. 17169. 17185. 17202. 1 821 17251. 17267. 17284. 17300. 17316. 17333. 17349. 17365. 1 822 17414. 17431. 17447. 17464. 17480. 17496. 17513. 17529. 1 823 17578. 17594. 17611. 17627. 17644. 17660. 17676. 17693. 1 824 17742. 17758. 17774. 17791. 17807. 17824. 17840. 17856. 1 825 17905. 17922. 17938. 17954. 17971. 17987. 18004. 18020. 1 826 18069. 18085. 18102. 18118. 18135. 18151. 18167. 18184. 1 827 18233. 18249. 18265. 18282. 18298. 18315. 18331. 18347. 1 828 18396. 18413. 18429. 18445. 18462. 18478. 18495. 18511. 1 829 18560. 18576. 18593. 18609. 18625. 18642. 18658. 18675. 1 830 18724. 18742. 18760. 18779. 18797. 18815. 18834. 18852. 1 831 18907. 18925. 18944. 18962. 18980. 18999. 19017. 19035. 1 832 19090. 19109. 19127. 19145. 19164. 19182. 19200. 19219. 1 833 19274. 19292. 19310. 19329. 19347. 19365. 19384. 19402. 1 834 19457. 19475. 19494. 19512. 19530. 19549. 19567. 19585. 1 835 19640. 19659. 19677. 19695. 19714. 19732. 19750. 19769. 1 836 19824. 19842. 19861. 19879. 19897. 19916. 19934. 19952. 1 837 20007. 20026. 20044. 20062. 20081. 20099. 20117. 20136. 2 838 20191. 20209. 20227. 20246. 20264. 20282. 20301. 20319. 2 839 20374. 20392. 20411. 20429. 20447. 20466. 20484. 20502. 2 840 20557. 20577. 20597. 20617. 20637. 20656. 20676. 20696. 2 841 20756. 20775. 20795. 20815. 20835. 20855. 20875. 20894. 2 842 20954. 20974. 20994. 21013. 21033. 21053. 21073. 21093. 2 843 21152. 21172. 21192. 21212. 21232. 21251. 21271. 21291. 2 844 21351. 21370. 21390. 21410. 21430. 21450. 21470. 21489. 2
5

 2001 LAKE MEAD - BOULDER CITY, NEVADA ( 2001 AREA-CAPACITY TABLES  THE AREA TABLE IS IN ACRES THE ELEVATION INCREMENT IS IN ONE TENTH  ELEV. FEET 0 .1 .2 .3 .4 .5 .6 .7  845 21549. 21569. 21589. 21608. 21628. 21648. 21668. 21688. 2 846 21747. 21767. 21787. 21807. 21827. 21846. 21866. 21886. 2 847 21946. 21965. 21985. 22005. 22025. 22045. 22064. 22084. 2 848 22144. 22164. 22183. 22203. 22223. 22243. 22263. 22283. 2 849 22342. 22362. 22382. 22402. 22421. 22441. 22461. 22481. 2 850 22540. 22558. 22576. 22593. 22611. 22628. 22646. 22663. 2 851 22716. 22734. 22751. 22769. 22786. 22804. 22821. 22839. 2 852 22892. 22909. 22927. 22944. 22962. 22979. 22997. 23014. 2 853 23067. 23085. 23102. 23120. 23137. 23155. 23172. 23190. 2 854 23243. 23260. 23278. 23295. 23313. 23330. 23348. 23365. 2 855 23418. 23436. 23453. 23471. 23488. 23506. 23523. 23541. 2 856 23594. 23611. 23629. 23646. 23664. 23681. 23699. 23717. 2 857 23769. 23787. 23804. 23822. 23839. 23857. 23875. 23892. 2 858 23945. 23962. 23980. 23997. 24015. 24032. 24050. 24068. 2 859 24120. 24138. 24155. 24173. 24190. 24208. 24226. 24243. 2 860 24296. 24312. 24327. 24343. 24359. 24375. 24391. 24406. 2 861 24454. 24470. 24486. 24501. 24517. 24533. 24549. 24565. 2 862 24612. 24628. 24644. 24659. 24675. 24691. 24707. 24723. 2 863 24770. 24786. 24802. 24818. 24833. 24849. 24865. 24881. 2 864 24928. 24944. 24960. 24976. 24992. 25007. 25023. 25039. 2 865 25086. 25102. 25118. 25134. 25150. 25165. 25181. 25197. 2 866 25244. 25260. 25276. 25292. 25308. 25324. 25339. 25355. 2 867 25403. 25418. 25434. 25450. 25466. 25482. 25497. 25513. 2 868 25561. 25577. 25592. 25608. 25624. 25640. 25656. 25671. 2 869 25719. 25735. 25750. 25766. 25782. 25798. 25814. 25830. 2 870 25877. 25893. 25910. 25926. 25942. 25958. 25975. 25991. 2 871 26040. 26056. 26072. 26088. 26105. 26121. 26137. 26153. 2 872 26202. 26218. 26235. 26251. 26267. 26284. 26300. 26316. 2 873 26365. 26381. 26397. 26414. 26430. 26446. 26462. 26479. 2 874 26527. 26544. 26560. 26576. 26593. 26609. 26625. 26641. 2 875 26690. 26706. 26723. 26739. 26755. 26771. 26788. 26804. 2 876 26853. 26869. 26885. 26901. 26918. 26934. 26950. 26967. 2 877 27015. 27032. 27048. 27064. 27080. 27097. 27113. 27129. 2 878 27178. 27194. 27210. 27227. 27243. 27259. 27276. 27292. 2 879 27341. 27357. 27373. 27389. 27406. 27422. 27438. 27454. 2 880 27503. 27520. 27537. 27554. 27571. 27588. 27604. 27621. 2 881 27672. 27689. 27706. 27723. 27740. 27756. 27773. 27790. 2 882 27841. 27858. 27875. 27891. 27908. 27925. 27942. 27959. 2 883 28010. 28027. 28043. 28060. 28077. 28094. 28111. 28128. 2 884 28178. 28195. 28212. 28229. 28246. 28263. 28280. 28297. 2
2001 Lake Mead Sedimentation Survey 

6

 2001 LAKE MEAD - BOULDER CITY, NEVADA (ACA 2001 AREA-CAPACITY TABLES  THE AREA TABLE IS IN ACRES THE ELEVATION INCREMENT IS IN ONE TENTH  ELEV. FEET 0 .1 .2 .3 .4 .5 .6 .7  885 28347. 28364. 28381. 28398. 28415. 28432. 28449. 28465. 2 886 28516. 28533. 28550. 28567. 28584. 28601. 28617. 28634. 2 887 28685. 28702. 28719. 28736. 28752. 28769. 28786. 28803. 2 888 28854. 28871. 28888. 28904. 28921. 28938. 28955. 28972. 2 889 29023. 29039. 29056. 29073. 29090. 29107. 29124. 29141. 2 890 29191. 29211. 29231. 29250. 29270. 29289. 29309. 29329. 2 891 29387. 29407. 29427. 29446. 29466. 29486. 29505. 29525. 2 892 29584. 29603. 29623. 29642. 29662. 29682. 29701. 29721. 2 893 29780. 29799. 29819. 29839. 29858. 29878. 29897. 29917. 2 894 29976. 29995. 30015. 30035. 30054. 30074. 30093. 30113. 3 895 30172. 30192. 30211. 30231. 30250. 30270. 30290. 30309. 3 896 30368. 30388. 30407. 30427. 30446. 30466. 30486. 30505. 3 897 30564. 30584. 30603. 30623. 30643. 30662. 30682. 30701. 3 898 30760. 30780. 30799. 30819. 30839. 30858. 30878. 30897. 3 899 30956. 30976. 30996. 31015. 31035. 31054. 31074. 31094. 3 900 31152. 31177. 31201. 31225. 31249. 31273. 31297. 31321. 3 901 31394. 31418. 31442. 31466. 31490. 31514. 31538. 31563. 3 902 31635. 31659. 31683. 31707. 31731. 31755. 31780. 31804. 3 903 31876. 31900. 31924. 31948. 31973. 31997. 32021. 32045. 3 904 32117. 32141. 32166. 32190. 32214. 32238. 32262. 32286. 3 905 32359. 32383. 32407. 32431. 32455. 32479. 32503. 32527. 3 906 32600. 32624. 32648. 32672. 32696. 32720. 32745. 32769. 3 907 32841. 32865. 32889. 32913. 32937. 32962. 32986. 33010. 3 908 33082. 33106. 33130. 33155. 33179. 33203. 33227. 33251. 3 909 33323. 33348. 33372. 33396. 33420. 33444. 33468. 33492. 3 910 33565. 33588. 33612. 33635. 33659. 33683. 33706. 33730. 3 911 33800. 33824. 33848. 33871. 33895. 33918. 33942. 33965. 3 912 34036. 34060. 34083. 34107. 34130. 34154. 34178. 34201. 3 913 34272. 34296. 34319. 34343. 34366. 34390. 34413. 34437. 3 914 34508. 34531. 34555. 34578. 34602. 34626. 34649. 34673. 3 915 34743. 34767. 34791. 34814. 34838. 34861. 34885. 34908. 3 916 34979. 35003. 35026. 35050. 35073. 35097. 35121. 35144. 3 917 35215. 35239. 35262. 35286. 35309. 35333. 35356. 35380. 3 918 35451. 35474. 35498. 35521. 35545. 35569. 35592. 35616. 3 919 35686. 35710. 35734. 35757. 35781. 35804. 35828. 35851. 3 920 35922. 35945. 35968. 35991. 36013. 36036. 36059. 36082. 3 921 36150. 36173. 36196. 36219. 36242. 36264. 36287. 36310. 3 922 36378. 36401. 36424. 36447. 36470. 36492. 36515. 36538. 3 923 36607. 36629. 36652. 36675. 36698. 36721. 36743. 36766. 3 924 36835. 36857. 36880. 36903. 36926. 36949. 36972. 36994. 3
7

 2001 LAKE MEAD - BOULDER CITY, NEVADA ( 2001 AREA-CAPACITY TABLES  THE AREA TABLE IS IN ACRES THE ELEVATION INCREMENT IS IN ONE TENTH  ELEV. FEET 0 .1 .2 .3 .4 .5 .6 .7  925 37063. 37086. 37108. 37131. 37154. 37177. 37200. 37222. 3 926 37291. 37314. 37337. 37359. 37382. 37405. 37428. 37451. 3 927 37519. 37542. 37565. 37587. 37610. 37633. 37656. 37679. 3 928 37747. 37770. 37793. 37816. 37838. 37861. 37884. 37907. 3 929 37975. 37998. 38021. 38044. 38066. 38089. 38112. 38135. 3 930 38203. 38227. 38250. 38273. 38296. 38320. 38343. 38366. 3 931 38436. 38459. 38482. 38505. 38529. 38552. 38575. 38598. 3 932 38668. 38691. 38714. 38738. 38761. 38784. 38807. 38831. 3 933 38900. 38924. 38947. 38970. 38993. 39016. 39040. 39063. 3 934 39133. 39156. 39179. 39202. 39226. 39249. 39272. 39295. 3 935 39365. 39388. 39411. 39435. 39458. 39481. 39504. 39528. 3 936 39597. 39621. 39644. 39667. 39690. 39713. 39737. 39760. 3 937 39830. 39853. 39876. 39899. 39923. 39946. 39969. 39992. 4 938 40062. 40085. 40108. 40132. 40155. 40178. 40201. 40225. 4 939 40294. 40317. 40341. 40364. 40387. 40410. 40434. 40457. 4 940 40527. 40550. 40573. 40597. 40620. 40644. 40667. 40691. 4 941 40761. 40784. 40808. 40831. 40854. 40878. 40901. 40925. 4 942 40995. 41018. 41042. 41065. 41089. 41112. 41136. 41159. 4 943 41229. 41253. 41276. 41300. 41323. 41346. 41370. 41393. 4 944 41463. 41487. 41510. 41534. 41557. 41581. 41604. 41627. 4 945 41698. 41721. 41745. 41768. 41791. 41815. 41838. 41862. 4 946 41932. 41955. 41979. 42002. 42026. 42049. 42073. 42096. 4 947 42166. 42190. 42213. 42236. 42260. 42283. 42307. 42330. 4 948 42400. 42424. 42447. 42471. 42494. 42518. 42541. 42564. 4 949 42635. 42658. 42682. 42705. 42728. 42752. 42775. 42799. 4 950 42869. 42895. 42921. 42947. 42973. 42999. 43024. 43050. 4 951 43128. 43154. 43180. 43206. 43232. 43258. 43284. 43310. 4 952 43387. 43413. 43439. 43465. 43491. 43517. 43543. 43569. 4 953 43647. 43672. 43698. 43724. 43750. 43776. 43802. 43828. 4 954 43906. 43932. 43958. 43983. 44009. 44035. 44061. 44087. 4 955 44165. 44191. 44217. 44243. 44269. 44295. 44320. 44346. 4 956 44424. 44450. 44476. 44502. 44528. 44554. 44580. 44606. 4 957 44683. 44709. 44735. 44761. 44787. 44813. 44839. 44865. 4 958 44943. 44968. 44994. 45020. 45046. 45072. 45098. 45124. 4 959 45202. 45228. 45254. 45279. 45305. 45331. 45357. 45383. 4 960 45461. 45485. 45509. 45533. 45556. 45580. 45604. 45628. 4 961 45700. 45723. 45747. 45771. 45795. 45819. 45843. 45867. 4 962 45938. 45962. 45986. 46010. 46034. 46057. 46081. 46105. 4 963 46177. 46200. 46224. 46248. 46272. 46296. 46320. 46344. 4 964 46415. 46439. 46463. 46487. 46511. 46534. 46558. 46582. 4
2001 Lake Mead Sedimentation Survey 

8

 2001 LAKE MEAD - BOULDER CITY, NEVADA ( 2001 AREA-CAPACITY TABLES  THE AREA TABLE IS IN ACRES THE ELEVATION INCREMENT IS IN ONE TENTH  ELEV. FEET 0 .1 .2 .3 .4 .5 .6 .7  965 46654. 46678. 46701. 46725. 46749. 46773. 46797. 46821. 4 966 46892. 46916. 46940. 46964. 46988. 47012. 47035. 47059. 4 967 47131. 47155. 47179. 47202. 47226. 47250. 47274. 47298. 4 968 47369. 47393. 47417. 47441. 47465. 47489. 47513. 47536. 4 969 47608. 47632. 47656. 47680. 47703. 47727. 47751. 47775. 4 970 47847. 47873. 47900. 47927. 47954. 47981. 48007. 48034. 4 971 48114. 48141. 48168. 48195. 48222. 48248. 48275. 48302. 4 972 48382. 48409. 48436. 48463. 48489. 48516. 48543. 48570. 4 973 48650. 48677. 48704. 48730. 48757. 48784. 48811. 48838. 4 974 48918. 48945. 48971. 48998. 49025. 49052. 49079. 49105. 4 975 49186. 49213. 49239. 49266. 49293. 49320. 49346. 49373. 4 976 49454. 49480. 49507. 49534. 49561. 49587. 49614. 49641. 4 977 49721. 49748. 49775. 49802. 49829. 49855. 49882. 49909. 4 978 49989. 50016. 50043. 50070. 50096. 50123. 50150. 50177. 5 979 50257. 50284. 50311. 50337. 50364. 50391. 50418. 50445. 5 980 50525. 50555. 50585. 50615. 50645. 50674. 50704. 50734. 5 981 50824. 50854. 50884. 50914. 50944. 50974. 51004. 51034. 5 982 51123. 51153. 51183. 51213. 51243. 51273. 51303. 51333. 5 983 51423. 51453. 51483. 51512. 51542. 51572. 51602. 51632. 5 984 51722. 51752. 51782. 51812. 51842. 51872. 51902. 51931. 5 985 52021. 52051. 52081. 52111. 52141. 52171. 52201. 52231. 5 986 52321. 52350. 52380. 52410. 52440. 52470. 52500. 52530. 5 987 52620. 52650. 52680. 52710. 52739. 52769. 52799. 52829. 5 988 52919. 52949. 52979. 53009. 53039. 53069. 53099. 53129. 5 989 53218. 53248. 53278. 53308. 53338. 53368. 53398. 53428. 5 990 53518. 53546. 53575. 53603. 53632. 53660. 53689. 53718. 5 991 53803. 53832. 53860. 53889. 53918. 53946. 53975. 54003. 5 992 54089. 54118. 54146. 54175. 54203. 54232. 54260. 54289. 5 993 54375. 54403. 54432. 54460. 54489. 54517. 54546. 54575. 5 994 54660. 54689. 54717. 54746. 54775. 54803. 54832. 54860. 5 995 54946. 54975. 55003. 55032. 55060. 55089. 55117. 55146. 5 996 55232. 55260. 55289. 55317. 55346. 55374. 55403. 55432. 5 997 55517. 55546. 55574. 55603. 55632. 55660. 55689. 55717. 5 998 55803. 55832. 55860. 55889. 55917. 55946. 55974. 56003. 5 999 56089. 56117. 56146. 56174. 56203. 56231. 56260. 56289. 5 1000 56374. 56405. 56436. 56467. 56498. 56529. 56560. 56591. 5 1001 56684. 56715. 56746. 56777. 56808. 56839. 56870. 56901. 5 1002 56995. 57026. 57057. 57088. 57119. 57150. 57181. 57212. 5 1003 57305. 57336. 57367. 57398. 57429. 57460. 57491. 57522. 5 1004 57615. 57646. 57677. 57708. 57739. 57770. 57801. 57832. 5
9

 2001 LAKE MEAD - BOULDER CITY, NEVADA (  2001 AREA-CAPACITY TABLES  THE AREA TABLE IS IN ACRES THE ELEVATION INCREMENT IS IN ONE TENTH  ELEV. FEET 0 .1 .2 .3 .4 .5 .6 .7  1005 57925. 57956. 57987. 58018. 58049. 58080. 58111. 58142. 5 1006 58235. 58266. 58297. 58328. 58359. 58390. 58421. 58452. 5 1007 58545. 58576. 58607. 58638. 58669. 58700. 58731. 58762. 5 1008 58855. 58886. 58917. 58948. 58979. 59010. 59041. 59072. 5 1009 59165. 59196. 59227. 59258. 59289. 59320. 59351. 59382. 5 1010 59475. 59506. 59537. 59567. 59598. 59628. 59659. 59690. 5 1011 59781. 59812. 59842. 59873. 59904. 59934. 59965. 59995. 6 1012 60087. 60118. 60148. 60179. 60209. 60240. 60270. 60301. 6 1013 60393. 60423. 60454. 60485. 60515. 60546. 60576. 60607. 6 1014 60699. 60729. 60760. 60790. 60821. 60851. 60882. 60913. 6 1015 61004. 61035. 61065. 61096. 61127. 61157. 61188. 61218. 6 1016 61310. 61341. 61371. 61402. 61432. 61463. 61494. 61524. 6 1017 61616. 61646. 61677. 61708. 61738. 61769. 61799. 61830. 6 1018 61922. 61952. 61983. 62013. 62044. 62075. 62105. 62136. 6 1019 62227. 62258. 62289. 62319. 62350. 62380. 62411. 62441. 6 1020 62533. 62564. 62595. 62626. 62657. 62688. 62719. 62750. 6 1021 62842. 62873. 62904. 62935. 62966. 62997. 63028. 63059. 6 1022 63151. 63182. 63213. 63244. 63275. 63306. 63337. 63368. 6 1023 63460. 63491. 63522. 63553. 63584. 63615. 63646. 63677. 6 1024 63769. 63800. 63831. 63862. 63893. 63924. 63955. 63986. 6 1025 64078. 64109. 64140. 64171. 64202. 64233. 64264. 64295. 6 1026 64387. 64418. 64449. 64480. 64511. 64542. 64573. 64604. 6 1027 64696. 64727. 64758. 64789. 64820. 64851. 64882. 64913. 6 1028 65006. 65036. 65067. 65098. 65129. 65160. 65191. 65222. 6 1029 65315. 65345. 65376. 65407. 65438. 65469. 65500. 65531. 6 1030 65624. 65656. 65688. 65720. 65752. 65784. 65816. 65848. 6 1031 65945. 65977. 66009. 66041. 66073. 66105. 66137. 66169. 6 1032 66266. 66298. 66330. 66362. 66394. 66426. 66458. 66490. 6 1033 66587. 66619. 66651. 66683. 66715. 66747. 66779. 66811. 6 1034 66908. 66940. 66972. 67004. 67036. 67068. 67100. 67133. 6 1035 67229. 67261. 67293. 67325. 67357. 67389. 67421. 67454. 6 1036 67550. 67582. 67614. 67646. 67678. 67710. 67742. 67775. 6 1037 67871. 67903. 67935. 67967. 67999. 68031. 68064. 68096. 6 1038 68192. 68224. 68256. 68288. 68320. 68352. 68385. 68417. 6 1039 68513. 68545. 68577. 68609. 68641. 68673. 68706. 68738. 6 1040 68834. 68868. 68901. 68935. 68969. 69003. 69036. 69070. 6 1041 69171. 69205. 69239. 69273. 69306. 69340. 69374. 69408. 6 1042 69509. 69543. 69576. 69610. 69644. 69677. 69711. 69745. 6 1043 69846. 69880. 69914. 69947. 69981. 70015. 70049. 70082. 7
2001 Lake Mead Sedimentation Survey 

10

 1044 70184. 70217. 70251. 70285. 70319. 70352. 70386. 70420. 7 2001 LAKE MEAD - BOULDER CITY, NEVADA ( 2001 AREA-CAPACITY TABLES  THE AREA TABLE IS IN ACRES THE ELEVATION INCREMENT IS IN ONE TENTH  ELEV. FEET 0 .1 .2 .3 .4 .5 .6 .7  1045 70521. 70555. 70588. 70622. 70656. 70690. 70723. 70757. 7 1046 70858. 70892. 70926. 70960. 70993. 71027. 71061. 71095. 7 1047 71196. 71230. 71263. 71297. 71331. 71364. 71398. 71432. 7 1048 71533. 71567. 71601. 71634. 71668. 71702. 71736. 71769. 7 1049 71871. 71904. 71938. 71972. 72006. 72039. 72073. 72107. 7 1050 72208. 72249. 72285. 72321. 72357. 72393. 72430. 72466. 7 1051 72574. 72611. 72647. 72683. 72719. 72755. 72792. 72828. 7 1052 72936. 72973. 73009. 73045. 73081. 73117. 73154. 73190. 7 1053 73298. 73335. 73371. 73407. 73443. 73479. 73515. 73552. 7 1054 73660. 73696. 73733. 73769. 73805. 73841. 73877. 73914. 7 1055 74022. 74058. 74095. 74131. 74167. 74203. 74239. 74276. 7 1056 74384. 74420. 74457. 74493. 74529. 74565. 74601. 74638. 7 1057 74746. 74782. 74818. 74855. 74891. 74927. 74963. 74999. 7 1058 75108. 75144. 75180. 75217. 75253. 75289. 75325. 75361. 7 1059 75470. 75506. 75542. 75579. 75615. 75651. 75687. 75723. 7 1060 75832. 75868. 75904. 75941. 75977. 76013. 76049. 76085. 7 1061 76194. 76230. 76266. 76302. 76339. 76375. 76411. 76447. 7 1062 76556. 76592. 76628. 76664. 76701. 76737. 76773. 76809. 7 1063 76918. 76954. 76990. 77026. 77063. 77099. 77135. 77171. 7 1064 77280. 77316. 77352. 77388. 77424. 77461. 77497. 77533. 7 1065 77642. 77678. 77714. 77750. 77786. 77823. 77859. 77895. 7 1066 78004. 78040. 78076. 78112. 78148. 78185. 78221. 78257. 7 1067 78366. 78402. 78438. 78474. 78510. 78547. 78583. 78619. 7 1068 78727. 78764. 78800. 78836. 78872. 78908. 78945. 78981. 7 1069 79089. 79126. 79162. 79198. 79234. 79270. 79307. 79343. 7 1070 79451. 79481. 79515. 79549. 79583. 79617. 79651. 79685. 7 1071 79787. 79821. 79855. 79889. 79923. 79957. 79991. 80025. 8 1072 80127. 80161. 80195. 80229. 80263. 80297. 80331. 80365. 8 1073 80468. 80502. 80536. 80570. 80604. 80638. 80672. 80706. 8 1074 80808. 80842. 80876. 80910. 80944. 80978. 81012. 81046. 8 1075 81148. 81182. 81216. 81250. 81284. 81318. 81352. 81386. 8 1076 81488. 81522. 81556. 81590. 81624. 81658. 81692. 81726. 8 1077 81828. 81862. 81896. 81931. 81965. 81999. 82033. 82067. 8 1078 82169. 82203. 82237. 82271. 82305. 82339. 82373. 82407. 8 1079 82509. 82543. 82577. 82611. 82645. 82679. 82713. 82747. 8 1080 82849. 82884. 82919. 82954. 82989. 83025. 83060. 83095. 8 1081 83200. 83235. 83270. 83305. 83340. 83375. 83411. 83446. 8 1082 83551. 83586. 83621. 83656. 83691. 83726. 83761. 83797. 8 1083 83902. 83937. 83972. 84007. 84042. 84077. 84112. 84147. 8 1084 84253. 84288. 84323. 84358. 84393. 84428. 84463. 84498. 8
11

 2001 LAKE MEAD - BOULDER CITY, NEVADA ( 2001 AREA-CAPACITY TABLES  THE AREA TABLE IS IN ACRES THE ELEVATION INCREMENT IS IN ONE TENTH  ELEV. FEET 0 .1 .2 .3 .4 .5 .6 .7  1085 84604. 84639. 84674. 84709. 84744. 84779. 84814. 84849. 8 1086 84954. 84990. 85025. 85060. 85095. 85130. 85165. 85200. 8 1087 85305. 85340. 85376. 85411. 85446. 85481. 85516. 85551. 8 1088 85656. 85691. 85726. 85762. 85797. 85832. 85867. 85902. 8 1089 86007. 86042. 86077. 86112. 86148. 86183. 86218. 86253. 8 1090 86358. 86393. 86427. 86462. 86496. 86531. 86565. 86600. 8 1091 86704. 86738. 86773. 86807. 86842. 86876. 86911. 86946. 8 1092 87049. 87084. 87118. 87153. 87187. 87222. 87257. 87291. 8 1093 87395. 87429. 87464. 87499. 87533. 87568. 87602. 87637. 8 1094 87740. 87775. 87810. 87844. 87879. 87913. 87948. 87982. 8 1095 88086. 88121. 88155. 88190. 88224. 88259. 88293. 88328. 8 1096 88432. 88466. 88501. 88535. 88570. 88604. 88639. 88674. 8 1097 88777. 88812. 88846. 88881. 88915. 88950. 88985. 89019. 8 1098 89123. 89157. 89192. 89226. 89261. 89296. 89330. 89365. 8 1099 89468. 89503. 89538. 89572. 89607. 89641. 89676. 89710. 8 1100 89814. 89855. 89895. 89935. 89976. 90016. 90057. 90097. 9 1101 90219. 90259. 90300. 90340. 90380. 90421. 90461. 90502. 9 1102 90623. 90664. 90704. 90745. 90785. 90826. 90866. 90906. 9 1103 91028. 91068. 91109. 91149. 91190. 91230. 91271. 91311. 9 1104 91432. 91473. 91513. 91554. 91594. 91635. 91675. 91716. 9 1105 91837. 91878. 91918. 91958. 91999. 92039. 92080. 92120. 9 1106 92242. 92282. 92323. 92363. 92404. 92444. 92484. 92525. 9 1107 92646. 92687. 92727. 92768. 92808. 92849. 92889. 92929. 9 1108 93051. 93091. 93132. 93172. 93213. 93253. 93294. 93334. 9 1109 93455. 93496. 93536. 93577. 93617. 93658. 93698. 93739. 9 1110 93860. 93904. 93943. 93982. 94020. 94059. 94097. 94136. 9 1111 94252. 94291. 94329. 94368. 94407. 94445. 94484. 94523. 9 1112 94639. 94677. 94716. 94755. 94793. 94832. 94870. 94909. 9 1113 95025. 95064. 95102. 95141. 95180. 95218. 95257. 95296. 9 1114 95412. 95450. 95489. 95528. 95566. 95605. 95643. 95682. 9 1115 95798. 95837. 95875. 95914. 95953. 95991. 96030. 96069. 9 1116 96185. 96223. 96262. 96301. 96339. 96378. 96416. 96455. 9 1117 96571. 96610. 96648. 96687. 96726. 96764. 96803. 96842. 9 1118 96958. 96996. 97035. 97074. 97112. 97151. 97189. 97228. 9 1119 97344. 97383. 97421. 97460. 97499. 97537. 97576. 97615. 9 1120 97731. 97769. 97808. 97847. 97885. 97924. 97962. 98001. 9 1121 98117. 98156. 98194. 98233. 98272. 98310. 98349. 98388. 9 1122 98504. 98542. 98581. 98620. 98658. 98697. 98735. 98774. 9 1123 98890. 98929. 98967. 99006. 99045. 99083. 99122. 99161. 9 1124 99277. 99315. 99354. 99393. 99431. 99470. 99508. 99547. 9
2001 Lake Mead Sedimentation Survey 

12

 2001 LAKE MEAD - BOULDER CITY, NEVADA ( 2001 AREA-CAPACITY TABLES  THE AREA TABLE IS IN ACRES THE ELEVATION INCREMENT IS IN ONE TENTH  ELEV. FEET 0 .1 .2 .3 .4 .5 .6 .7  1125 99663. 99702. 99740. 99779. 99818. 99856. 99895. 99934. 9 1126 100050. 100088. 100127. 100166. 100204. 100243. 100281. 100320. 10 1127 100436. 100475. 100513. 100552. 100591. 100629. 100668. 100707. 10 1128 100823. 100861. 100900. 100939. 100977. 101016. 101054. 101093. 10 1129 101209. 101248. 101286. 101325. 101364. 101402. 101441. 101480. 10 1130 101596. 101632. 101675. 101717. 101759. 101802. 101844. 101886. 10 1131 102013. 102056. 102098. 102141. 102183. 102225. 102268. 102310. 10 1132 102437. 102479. 102522. 102564. 102606. 102649. 102691. 102733. 10 1133 102860. 102903. 102945. 102987. 103030. 103072. 103114. 103157. 10 1134 103284. 103326. 103368. 103411. 103453. 103495. 103538. 103580. 10 1135 103707. 103749. 103792. 103834. 103876. 103919. 103961. 104004. 10 1136 104131. 104173. 104215. 104258. 104300. 104342. 104385. 104427. 10 1137 104554. 104596. 104639. 104681. 104723. 104766. 104808. 104850. 10 1138 104977. 105020. 105062. 105104. 105147. 105189. 105231. 105274. 10 1139 105401. 105443. 105485. 105528. 105570. 105612. 105655. 105697. 10 1140 105824. 105876. 105929. 105981. 106033. 106086. 106138. 106190. 10 1141 106347. 106399. 106452. 106504. 106556. 106609. 106661. 106713. 10 1142 106870. 106923. 106975. 107027. 107080. 107132. 107184. 107237. 10 1143 107394. 107446. 107498. 107551. 107603. 107655. 107708. 107760. 10 1144 107917. 107969. 108021. 108074. 108126. 108178. 108231. 108283. 10 1145 108440. 108492. 108545. 108597. 108649. 108702. 108754. 108806. 10 1146 108963. 109016. 109068. 109120. 109173. 109225. 109277. 109329. 10 1147 109486. 109539. 109591. 109643. 109696. 109748. 109800. 109853. 10 1148 110010. 110062. 110114. 110167. 110219. 110271. 110324. 110376. 11 1149 110533. 110585. 110638. 110690. 110742. 110794. 110847. 110899. 11 1150 111056. 111101. 111148. 111194. 111240. 111286. 111333. 111379. 11 1151 111518. 111564. 111610. 111657. 111703. 111749. 111795. 111842. 11 1152 111981. 112027. 112073. 112119. 112166. 112212. 112258. 112304. 11 1153 112443. 112490. 112536. 112582. 112628. 112675. 112721. 112767. 11 1154 112906. 112952. 112999. 113045. 113091. 113137. 113184. 113230. 11 1155 113369. 113415. 113461. 113508. 113554. 113600. 113646. 113693. 11 1156 113832. 113878. 113924. 113970. 114017. 114063. 114109. 114156. 11 1157 114294. 114341. 114387. 114433. 114479. 114526. 114572. 114618. 11 1158 114757. 114803. 114850. 114896. 114942. 114988. 115035. 115081. 11 1159 115220. 115266. 115312. 115359. 115405. 115451. 115498. 115544. 11 1160 115683. 115729. 115775. 115821. 115868. 115914. 115960. 116007. 11 1161 116145. 116192. 116238. 116284. 116330. 116377. 116423. 116469. 11 1162 116608. 116654. 116701. 116747. 116793. 116840. 116886. 116932. 11 1163 117071. 117117. 117163. 117210. 117256. 117302. 117349. 117395. 11 1164 117534. 117580. 117626. 117673. 117719. 117765. 117811. 117858. 11
13

 2001 LAKE MEAD - BOULDER CITY, NEVADA ( 2001 AREA-CAPACITY TABLES  THE AREA TABLE IS IN ACRES THE ELEVATION INCREMENT IS IN ONE TENTH  ELEV. FEET 0 .1 .2 .3 .4 .5 .6 .7  1165 117996. 118043. 118089. 118135. 118182. 118228. 118274. 118320. 11 1166 118459. 118505. 118552. 118598. 118644. 118691. 118737. 118783. 11 1167 118922. 118968. 119015. 119061. 119107. 119153. 119200. 119246. 11 1168 119385. 119431. 119477. 119524. 119570. 119616. 119662. 119709. 11 1169 119848. 119894. 119940. 119986. 120033. 120079. 120125. 120171. 12 1170 120310. 120375. 120438. 120502. 120565. 120629. 120692. 120756. 12 1171 120946. 121010. 121073. 121137. 121200. 121264. 121328. 121391. 12 1172 121582. 121645. 121709. 121772. 121836. 121899. 121963. 122026. 12 1173 122217. 122280. 122344. 122407. 122471. 122535. 122598. 122662. 12 1174 122852. 122916. 122979. 123043. 123106. 123170. 123233. 123297. 12 1175 123487. 123551. 123614. 123678. 123742. 123805. 123869. 123932. 12 1176 124123. 124186. 124250. 124313. 124377. 124440. 124504. 124567. 12 1177 124758. 124821. 124885. 124948. 125012. 125076. 125139. 125203. 12 1178 125393. 125457. 125520. 125584. 125647. 125711. 125774. 125838. 12 1179 126028. 126092. 126155. 126219. 126283. 126346. 126410. 126473. 12 1180 126664. 126753. 126842. 126930. 127019. 127108. 127197. 127286. 12 1181 127553. 127642. 127731. 127820. 127908. 127997. 128086. 128175. 12 1182 128442. 128531. 128620. 128709. 128798. 128886. 128975. 129064. 12 1183 129331. 129420. 129509. 129598. 129687. 129776. 129865. 129953. 13 1184 130220. 130309. 130398. 130487. 130576. 130665. 130754. 130843. 13 1185 131109. 131198. 131287. 131376. 131465. 131554. 131643. 131732. 13 1186 131998. 132087. 132176. 132265. 132354. 132443. 132532. 132621. 13 1187 132888. 132976. 133065. 133154. 133243. 133332. 133421. 133510. 13 1188 133777. 133866. 133954. 134043. 134132. 134221. 134310. 134399. 13 1189 134666. 134755. 134844. 134932. 135021. 135110. 135199. 135288. 13 1190 135555. 135635. 135715. 135795. 135875. 135955. 136035. 136115. 13 1191 136356. 136436. 136516. 136596. 136676. 136756. 136836. 136916. 13 1192 137157. 137237. 137317. 137397. 137477. 137557. 137637. 137717. 13 1193 137957. 138037. 138118. 138198. 138278. 138358. 138438. 138518. 13 1194 138758. 138838. 138918. 138998. 139079. 139159. 139239. 139319. 13 1195 139559. 139639. 139719. 139799. 139879. 139960. 140040. 140120. 14 1196 140360. 140440. 140520. 140600. 140680. 140760. 140840. 140921. 14 1197 141161. 141241. 141321. 141401. 141481. 141561. 141641. 141721. 14 1198 141962. 142042. 142122. 142202. 142282. 142362. 142442. 142522. 14 1199 142762. 142843. 142923. 143003. 143083. 143163. 143243. 143323. 14 1200 143563. 143637. 143710. 143784. 143857. 143931. 144005. 144078. 14 1201 144299. 144372. 144446. 144519. 144593. 144667. 144740. 144814. 14 1202 145034. 145108. 145182. 145255. 145329. 145402. 145476. 145549. 14 1203 145770. 145844. 145917. 145991. 146064. 146138. 146211. 146285. 14 1204 146506. 146579. 146653. 146726. 146800. 146873. 146947. 147021. 14
2001 Lake Mead Sedimentation Survey 

14

 2001 LAKE MEAD - BOULDER CITY, NEVADA ( 2001 AREA-CAPACITY TABLES  THE AREA TABLE IS IN ACRES THE ELEVATION INCREMENT IS IN ONE TENTH  ELEV. FEET 0 .1 .2 .3 .4 .5 .6 .7  1205 147241. 147315. 147388. 147462. 147535. 147609. 147683. 147756. 14 1206 147977. 148050. 148124. 148198. 148271. 148345. 148418. 148492. 14 1207 148712. 148786. 148860. 148933. 149007. 149080. 149154. 149227. 14 1208 149448. 149522. 149595. 149669. 149742. 149816. 149889. 149963. 15 1209 150184. 150257. 150331. 150404. 150478. 150551. 150625. 150699. 15 1210 150919. 150975. 151030. 151086. 151141. 151197. 151252. 151308. 15 1211 151475. 151530. 151586. 151641. 151697. 151752. 151808. 151863. 15 1212 152030. 152085. 152141. 152197. 152252. 152308. 152363. 152419. 15 1213 152585. 152641. 152696. 152752. 152807. 152863. 152918. 152974. 15 1214 153141. 153196. 153252. 153307. 153363. 153418. 153474. 153529. 15 1215 153696. 153751. 153807. 153863. 153918. 153974. 154029. 154085. 15 1216 154251. 154307. 154362. 154418. 154473. 154529. 154584. 154640. 15 1217 154807. 154862. 154918. 154973. 155029. 155084. 155140. 155195. 15 1218 155362. 155417. 155473. 155529. 155584. 155640. 155695. 155751. 15 1219 155917. 155973. 156028. 156084. 156139. 156195. 156250. 156306. 15 1220 156473. 156540. 156608. 156675. 156743. 156810. 156878. 156945. 15 1221 157148. 157215. 157283. 157350. 157418. 157485. 157553. 157620. 15 1222 157823. 157890. 157958. 158025. 158093. 158160. 158228. 158295. 15 1223 158498. 158565. 158633. 158700. 158768. 158836. 158903. 158971. 15 1224 159173. 159241. 159308. 159376. 159443. 159511. 159578. 159646. 15 1225 159848. 159916. 159983. 160051. 160118. 160186. 160253. 160321. 16 1226 160523. 160591. 160658. 160726. 160793. 160861. 160928. 160996. 16 1227 161198. 161266. 161333. 161401. 161468. 161536. 161603. 161671. 16 1228 161873. 161941. 162008. 162076. 162143. 162211. 162278. 162346. 16 1229 162548. 162616. 162683. 162751. 162818. 162886. 162953. 163021. 16 1230 163223. 
15

 2001 LAKE MEAD - BOULDER CITY, NEVADA (A 2001 AREA-CAPACITY TABLES  THE CAPACITY TABLE IS IN ACRE FEET THE ELEVATION INCREMENT IS  ELEV. FEET 0 .1 .2 .3 .4 .5 .6 .7  689 0. 0. 0. 0. 0. 0. 0. 0.  690 0. 0. 0. 0. 0. 0. 0. 0.  691 0. 0. 0. 0. 0. 0. 0. 0.  692 0. 0. 0. 0. 0. 0. 0. 0.  693 0. 0. 0. 0. 0. 0. 0. 0.  694 1. 1. 1. 1. 1. 1. 1. 1.  695 1. 1. 1. 1. 1. 1. 1. 1.  696 1. 1. 1. 1. 1. 1. 1. 1.  697 1. 1. 1. 1. 2. 2. 2. 2.  698 2. 2. 2. 2. 2. 2. 2. 2.  699 2. 2. 2. 2. 2. 2. 2. 2.  700 3. 3. 3. 3. 3. 3. 3. 3.  701 3. 3. 3. 3. 4. 4. 4. 4.  702 4. 4. 4. 5. 5. 5. 5. 5.  703 6. 6. 6. 6. 6. 6. 7. 7.  704 7. 7. 8. 8. 8. 8. 8. 9.  705 9. 9. 10. 10. 10. 10. 11. 11.  706 12. 12. 12. 12. 13. 13. 13. 14.  707 14. 15. 15. 15. 16. 16. 16. 16.  708 17. 18. 18. 18. 19. 19. 19. 20.  709 21. 21. 22. 22. 22. 23. 23. 23.  710 25. 25. 26. 26. 27. 27. 28. 29.  711 31. 32. 33. 34. 35. 36. 37. 39.  712 43. 44. 45. 47. 48. 50. 52. 53.  713 59. 61. 63. 65. 67. 69. 71. 73.  714 80. 83. 85. 88. 90. 93. 96. 98.  715 107. 110. 113. 116. 119. 122. 125. 128.  716 138. 142. 145. 149. 152. 156. 159. 163.  717 175. 178. 182. 186. 190. 195. 199. 203.  718 216. 220. 225. 229. 234. 238. 243. 248.  719 262. 267. 272. 277. 282. 287. 293. 298.  720 314. 320. 327. 336. 346. 357. 369. 383.  721 432. 451. 472. 493. 516. 540. 566. 593.  722 681. 713. 746. 780. 816. 853. 892. 932.  723 1059. 1103. 1150. 1197. 1246. 1296. 1347. 1400.  724 1566. 1624. 1683. 1744. 1805. 1868. 1933. 1998. 
2001 Lake Mead Sedimentation Survey 

16

 2001 LAKE MEAD - BOULDER CITY, NEVADA (A 2001 AREA-CAPACITY TABLES  THE CAPACITY TABLE IS IN ACRE FEET THE ELEVATION INCREMENT IS  ELEV. FEET 0 .1 .2 .3 .4 .5 .6 .7  725 2203. 2274. 2346. 2420. 2494. 2570. 2648. 2726.  726 2970. 3054. 3139. 3225. 3313. 3402. 3492. 3584.  727 3866. 3963. 4061. 4160. 4261. 4363. 4466. 4571.  728 4892. 5002. 5113. 5225. 5339. 5454. 5570. 5687.  729 6048. 6170. 6294. 6420. 6546. 6674. 6803. 6934.  730 7333. 7469. 7607. 7746. 7887. 8031. 8176. 8322.  731 8774. 8928. 9083. 9241. 9401. 9562. 9725. 9890. 1 732 10395. 10568. 10741. 10917. 11095. 11274. 11455. 11638. 1 733 12198. 12389. 12581. 12775. 12970. 13168. 13367. 13568. 1 734 14183. 14391. 14601. 14813. 15027. 15243. 15460. 15680. 1 735 16348. 16575. 16803. 17033. 17265. 17499. 17735. 17972. 1 736 18695. 18940. 19186. 19434. 19685. 19936. 20190. 20446. 2 737 21223. 21486. 21750. 22017. 22285. 22555. 22827. 23101. 2 738 23932. 24213. 24496. 24780. 25067. 25355. 25645. 25937. 2 739 26823. 27122. 27423. 27725. 28030. 28336. 28644. 28954. 2 740 29895. 30212. 30530. 30851. 31172. 31496. 31821. 32148. 3 741 33138. 33471. 33806. 34142. 34480. 34820. 35162. 35504. 3 742 36543. 36892. 37243. 37596. 37950. 38306. 38664. 39023. 3 743 40110. 40476. 40843. 41212. 41582. 41954. 42328. 42703. 4 744 43839. 44220. 44604. 44989. 45376. 45764. 46154. 46545. 4 745 47729. 48127. 48527. 48928. 49331. 49735. 50141. 50549. 5 746 51782. 52196. 52612. 53029. 53448. 53869. 54291. 54715. 5 747 55996. 56426. 56858. 57292. 57727. 58164. 58602. 59042. 5 748 60372. 60819. 61267. 61717. 62168. 62621. 63076. 63532. 6 749 64910. 65373. 65837. 66303. 66771. 67240. 67711. 68183. 6 750 69610. 70089. 70569. 71050. 71532. 72016. 72500. 72986. 7 751 74451. 74942. 75434. 75927. 76421. 76917. 77413. 77911. 7 752 79412. 79915. 80419. 80924. 81431. 81938. 82447. 82957. 8 753 84494. 85009. 85525. 86042. 86561. 87080. 87601. 88123. 8 754 89696. 90223. 90751. 91280. 91811. 92342. 92875. 93409. 9 755 95019. 95558. 96098. 96639. 97181. 97725. 98270. 98816. 9 756 100462. 101013. 101565. 102118. 102673. 103228. 103785. 104343. 10 757 106025. 106588. 107152. 107717. 108284. 108852. 109421. 109991. 11 758 111709. 112284. 112860. 113437. 114016. 114596. 115177. 115759. 11 759 117513. 118100. 118688. 119277. 119868. 120460. 121053. 121647. 12 760 123437. 124036. 124636. 125237. 125839. 126441. 127045. 127649. 12 761 129468. 130076. 130685. 131295. 131906. 132518. 133131. 133745. 13 762 135591. 136209. 136827. 137446. 138066. 138688. 139310. 139933. 14 763 141807. 142434. 143061. 143690. 144319. 144949. 145581. 146213. 14 764 148115. 148751. 149388. 150025. 150664. 151304. 151944. 152585. 15
17

 2001 LAKE MEAD - BOULDER CITY, NEVADA (A 2001 AREA-CAPACITY TABLES  THE CAPACITY TABLE IS IN ACRE FEET THE ELEVATION INCREMENT IS  ELEV. FEET 0 .1 .2 .3 .4 .5 .6 .7  765 154515. 155160. 155806. 156453. 157101. 157750. 158400. 159050. 15 766 161008. 161662. 162318. 162974. 163631. 164289. 164948. 165608. 16 767 167593. 168257. 168921. 169586. 170253. 170920. 171588. 172257. 17 768 174270. 174943. 175617. 176292. 176967. 177644. 178321. 179000. 17 769 181040. 181722. 182405. 183089. 183774. 184460. 185146. 185834. 18 770 187902. 188594. 189287. 189981. 190676. 191373. 192071. 192770. 19 771 194876. 195581. 196287. 196994. 197703. 198413. 199124. 199837. 20 772 201982. 202700. 203419. 204139. 204861. 205584. 206308. 207034. 20 773 209219. 209950. 210682. 211416. 212151. 212887. 213624. 214363. 21 774 216588. 217332. 218077. 218824. 219572. 220321. 221072. 221824. 22 775 224088. 224845. 225603. 226363. 227124. 227887. 228651. 229416. 23 776 231719. 232489. 233261. 234034. 234808. 235584. 236361. 237139. 23 777 239482. 240266. 241050. 241837. 242624. 243413. 244203. 244994. 24 778 247376. 248173. 248971. 249770. 250571. 251373. 252176. 252981. 25 779 255402. 256212. 257023. 257836. 258650. 259465. 260281. 261099. 26 780 263560. 264383. 265207. 266033. 266861. 267689. 268520. 269351. 27 781 271855. 272693. 273531. 274372. 275214. 276057. 276901. 277747. 27 782 280294. 281146. 282000. 282854. 283710. 284568. 285427. 286288. 28 783 288878. 289744. 290612. 291481. 292352. 293224. 294097. 294972. 29 784 297605. 298486. 299368. 300252. 301137. 302023. 302911. 303800. 30 785 306477. 307372. 308269. 309167. 310066. 310967. 311869. 312773. 31 786 315493. 316402. 317313. 318226. 319140. 320055. 320972. 321890. 32 787 324653. 325577. 326502. 327429. 328357. 329287. 330218. 331150. 33 788 333957. 334895. 335835. 336776. 337719. 338663. 339608. 340555. 34 789 343405. 344358. 345312. 346267. 347224. 348183. 349143. 350104. 35 790 352997. 353965. 354937. 355913. 356892. 357874. 358861. 359850. 36 791 362842. 363846. 364854. 365865. 366880. 367899. 368921. 369947. 37 792 373046. 374086. 375130. 376178. 377229. 378283. 379342. 380404. 38 793 383611. 384687. 385767. 386850. 387937. 389028. 390122. 391220. 39 794 394536. 395648. 396764. 397883. 399006. 400133. 401263. 402397. 40 795 405820. 406969. 408121. 409276. 410435. 411598. 412764. 413934. 41 796 417466. 418650. 419838. 421029. 422224. 423423. 424626. 425831. 42 797 429471. 430691. 431915. 433143. 434374. 435609. 436847. 438089. 43 798 441836. 443093. 444353. 445616. 446883. 448154. 449428. 450706. 45 799 454562. 455854. 457150. 458450. 459753. 461060. 462370. 463684. 46 800 467648. 468975. 470305. 471636. 472970. 474305. 475642. 476982. 47 801 481012. 482359. 483708. 485059. 486413. 487768. 489125. 490484. 49 802 494573. 495940. 497309. 498680. 500052. 501427. 502804. 504183. 50 803 508331. 509717. 511106. 512497. 513889. 515284. 516680. 518078. 51 804 522286. 523692. 525100. 526510. 527923. 529337. 530753. 532171. 53
2001 Lake Mead Sedimentation Survey 

18

 2001 LAKE MEAD - BOULDER CITY, NEVADA (A 2001 AREA-CAPACITY TABLES  THE CAPACITY TABLE IS IN ACRE FEET THE ELEVATION INCREMENT IS  ELEV. FEET 0 .1 .2 .3 .4 .5 .6 .7  805 536437. 537863. 539291. 540721. 542153. 543587. 545023. 546461. 54 806 550786. 552232. 553679. 555129. 556581. 558034. 559490. 560947. 56 807 565331. 566797. 568264. 569733. 571205. 572678. 574153. 575630. 57 808 580074. 581559. 583046. 584535. 586026. 587519. 589014. 590511. 59 809 595013. 596518. 598024. 599533. 601044. 602556. 604071. 605588. 60 810 610149. 611674. 613200. 614728. 616258. 617790. 619323. 620859. 62 811 625476. 627019. 628564. 630111. 631659. 633209. 634762. 636316. 63 812 640989. 642550. 644113. 645679. 647246. 648814. 650385. 651958. 65 813 656686. 658266. 659848. 661432. 663017. 664605. 666194. 667785. 66 814 672569. 674168. 675768. 677370. 678974. 680580. 682188. 683798. 68 815 688638. 690255. 691874. 693494. 695117. 696741. 698367. 699996. 70 816 704891. 706527. 708164. 709803. 711444. 713087. 714732. 716379. 71 817 721330. 722984. 724640. 726298. 727957. 729619. 731282. 732947. 73 818 737954. 739626. 741301. 742977. 744655. 746335. 748017. 749701. 75 819 754763. 756454. 758147. 759842. 761539. 763237. 764938. 766640. 76 820 771758. 773467. 775178. 776891. 778606. 780322. 782039. 783759. 78 821 788927. 790652. 792380. 794109. 795840. 797572. 799306. 801042. 80 822 806259. 808001. 809745. 811491. 813238. 814987. 816737. 818489. 82 823 823755. 825514. 827274. 829036. 830800. 832565. 834332. 836100. 83 824 841415. 843190. 844967. 846745. 848525. 850307. 852090. 853875. 85 825 859239. 861030. 862823. 864618. 866414. 868212. 870012. 871813. 87 826 877226. 879034. 880843. 882654. 884467. 886281. 888097. 889915. 89 827 895377. 897201. 899027. 900854. 902683. 904514. 906346. 908180. 91 828 913692. 915532. 917374. 919218. 921063. 922910. 924759. 926609. 92 829 932170. 934027. 935885. 937745. 939607. 941470. 943335. 945202. 94 830 950812. 952685. 954560. 956437. 958316. 960196. 962079. 963963. 96 831 969627. 971518. 973412. 975307. 977204. 979103. 981004. 982907. 98 832 988626. 990536. 992447. 994361. 996276. 998194. 1000113. 1002034. 100 833 1007808. 1009736. 1011666. 1013598. 1015532. 1017467. 1019405. 1021344. 102 834 1027173. 1029120. 1031068. 1033018. 1034971. 1036925. 1038880. 1040838. 104 835 1046722. 1048687. 1050654. 1052622. 1054593. 1056565. 1058539. 1060515. 106 836 1066454. 1068437. 1070422. 1072409. 1074398. 1076389. 1078381. 1080376. 108 837 1086370. 1088371. 1090375. 1092380. 1094387. 1096396. 1098407. 1100419. 110 838 1106468. 1108488. 1110510. 1112534. 1114559. 1116587. 1118616. 1120647. 112 839 1126751. 1128789. 1130829. 1132871. 1134915. 1136961. 1139008. 1141057. 114 840 1147216. 1149273. 1151332. 1153392. 1155455. 1157520. 1159586. 1161655. 116 841 1167873. 1169949. 1172028. 1174108. 1176191. 1178275. 1180362. 1182450. 118 842 1188728. 1190824. 1192922. 1195023. 1197125. 1199229. 1201336. 1203444. 120 843 1209781. 1211897. 1214015. 1216135. 1218257. 1220382. 1222508. 1224636. 122 844 1231032. 1233168. 1235306. 1237446. 1239588. 1241732. 1243878. 1246026. 124
19

 2001 LAKE MEAD - BOULDER CITY, NEVADA (A 2001 AREA-CAPACITY TABLES  THE CAPACITY TABLE IS IN ACRE FEET THE ELEVATION INCREMENT IS  ELEV. FEET 0 .1 .2 .3 .4 .5 .6 .7  845 1252482. 1254638. 1256795. 1258955. 1261117. 1263281. 1265447. 1267615. 126 846 1274130. 1276305. 1278483. 1280663. 1282844. 1285028. 1287214. 1289401. 129 847 1295976. 1298172. 1300369. 1302569. 1304770. 1306974. 1309179. 1311387. 131 848 1318021. 1320236. 1322453. 1324673. 1326894. 1329117. 1331343. 1333570. 133 849 1340264. 1342499. 1344736. 1346975. 1349216. 1351460. 1353705. 1355952. 135 850 1362705. 1364960. 1367217. 1369475. 1371735. 1373997. 1376261. 1378526. 138 851 1385333. 1387606. 1389880. 1392156. 1394434. 1396713. 1398994. 1401278. 140 852 1408137. 1410427. 1412719. 1415012. 1417308. 1419605. 1421904. 1424204. 142 853 1431116. 1433424. 1435733. 1438044. 1440357. 1442672. 1444988. 1447306. 144 854 1454271. 1456596. 1458923. 1461252. 1463582. 1465914. 1468248. 1470584. 147 855 1477602. 1479944. 1482289. 1484635. 1486983. 1489332. 1491684. 1494037. 149 856 1501107. 1503468. 1505830. 1508193. 1510559. 1512926. 1515295. 1517666. 152 857 1524789. 1527167. 1529546. 1531927. 1534311. 1536695. 1539082. 1541470. 154 858 1548646. 1551041. 1553438. 1555837. 1558238. 1560640. 1563044. 1565450. 156 859 1572678. 1575091. 1577506. 1579922. 1582340. 1584760. 1587182. 1589606. 159 860 1596886. 1599317. 1601749. 1604182. 1606617. 1609054. 1611492. 1613932. 161 861 1621261. 1623707. 1626155. 1628604. 1631055. 1633508. 1635962. 1638418. 164 862 1645794. 1648256. 1650720. 1653185. 1655652. 1658120. 1660590. 1663061. 166 863 1670485. 1672963. 1675442. 1677923. 1680406. 1682890. 1685376. 1687863. 169 864 1695334. 1697828. 1700323. 1702820. 1705318. 1707818. 1710320. 1712823. 171 865 1720342. 1722851. 1725362. 1727875. 1730389. 1732905. 1735422. 1737941. 174 866 1745507. 1748032. 1750559. 1753088. 1755618. 1758149. 1760682. 1763217. 176 867 1770831. 1773372. 1775914. 1778459. 1781004. 1783552. 1786101. 1788651. 179 868 1796312. 1798869. 1801428. 1803988. 1806549. 1809113. 1811677. 1814244. 181 869 1821952. 1824525. 1827099. 1829675. 1832252. 1834831. 1837412. 1839994. 184 870 1847750. 1850339. 1852929. 1855520. 1858114. 1860709. 1863306. 1865904. 186 871 1873708. 1876313. 1878920. 1881528. 1884137. 1886748. 1889361. 1891976. 189 872 1899829. 1902450. 1905073. 1907697. 1910323. 1912951. 1915580. 1918211. 192 873 1926113. 1928750. 1931389. 1934030. 1936672. 1939316. 1941961. 1944608. 194 874 1952559. 1955212. 1957868. 1960524. 1963183. 1965843. 1968505. 1971168. 197 875 1979168. 1981838. 1984509. 1987182. 1989857. 1992533. 1995211. 1997891. 200 876 2005939. 2008625. 2011313. 2014002. 2016693. 2019386. 2022080. 2024776. 202 877 2032873. 2035575. 2038279. 2040985. 2043692. 2046401. 2049112. 2051824. 205 878 2059970. 2062688. 2065409. 2068130. 2070854. 2073579. 2076306. 2079034. 208 879 2087229. 2089964. 2092700. 2095439. 2098178. 2100920. 2103663. 2106407. 210 880 2114651. 2117402. 2120155. 2122909. 2125666. 2128424. 2131183. 2133944. 213 881 2142238. 2145007. 2147776. 2150548. 2153321. 2156096. 2158872. 2161650. 216 882 2169995. 2172780. 2175566. 2178355. 2181145. 2183936. 2186730. 2189525. 219 883 2197920. 2200722. 2203525. 2206331. 2209138. 2211946. 2214756. 2217568. 222 884 2226014. 2228833. 2231653. 2234475. 2237299. 2240125. 2242952. 2245781. 224
2001 Lake Mead Sedimentation Survey 

20

 2001 LAKE MEAD - BOULDER CITY, NEVADA (A 2001 AREA-CAPACITY TABLES  THE CAPACITY TABLE IS IN ACRE FEET THE ELEVATION INCREMENT IS  ELEV. FEET 0 .1 .2 .3 .4 .5 .6 .7  885 2254277. 2257113. 2259950. 2262789. 2265630. 2268472. 2271316. 2274162. 227 886 2282709. 2285561. 2288415. 2291271. 2294129. 2296988. 2299849. 2302711. 230 887 2311309. 2314179. 2317050. 2319922. 2322797. 2325673. 2328551. 2331430. 233 888 2340079. 2342965. 2345853. 2348742. 2351634. 2354527. 2357421. 2360318. 236 889 2369017. 2371920. 2374825. 2377731. 2380639. 2383549. 2386461. 2389374. 239 890 2398124. 2401044. 2403966. 2406890. 2409816. 2412744. 2415674. 2418606. 242 891 2427413. 2430353. 2433295. 2436238. 2439184. 2442132. 2445081. 2448033. 245 892 2456899. 2459858. 2462820. 2465783. 2468748. 2471715. 2474684. 2477655. 248 893 2486581. 2489559. 2492540. 2495523. 2498508. 2501495. 2504484. 2507474. 251 894 2516458. 2519457. 2522457. 2525460. 2528464. 2531471. 2534479. 2537489. 254 895 2546532. 2549550. 2552570. 2555593. 2558617. 2561643. 2564671. 2567701. 257 896 2576802. 2579840. 2582880. 2585921. 2588965. 2592011. 2595058. 2598108. 260 897 2607268. 2610326. 2613385. 2616446. 2619509. 2622575. 2625642. 2628711. 263 898 2637930. 2641007. 2644086. 2647167. 2650250. 2653335. 2656422. 2659511. 266 899 2668789. 2671885. 2674984. 2678084. 2681187. 2684291. 2687398. 2690506. 269 900 2699843. 2702959. 2706078. 2709199. 2712323. 2715449. 2718578. 2721709. 272 901 2731116. 2734256. 2737399. 2740545. 2743693. 2746843. 2749996. 2753151. 275 902 2762630. 2765795. 2768962. 2772132. 2775303. 2778478. 2781655. 2784834. 278 903 2794386. 2797575. 2800766. 2803959. 2807155. 2810354. 2813555. 2816758. 281 904 2826383. 2829595. 2832811. 2836028. 2839249. 2842471. 2845696. 2848924. 285 905 2858620. 2861857. 2865097. 2868339. 2871583. 2874830. 2878079. 2881330. 288 906 2891100. 2894361. 2897624. 2900890. 2904159. 2907430. 2910703. 2913978. 291 907 2923820. 2927105. 2930393. 2933683. 2936975. 2940271. 2943568. 2946868. 295 908 2956782. 2960091. 2963403. 2966717. 2970034. 2973353. 2976674. 2979998. 298 909 2989984. 2993318. 2996654. 2999992. 3003333. 3006676. 3010022. 3013370. 301 910 3023428. 3026786. 3030146. 3033508. 3036873. 3040240. 3043610. 3046981. 305 911 3057111. 3060492. 3063876. 3067262. 3070650. 3074041. 3077434. 3080829. 308 912 3091029. 3094434. 3097841. 3101251. 3104663. 3108077. 3111493. 3114912. 311 913 3125183. 3128612. 3132042. 3135475. 3138911. 3142349. 3145789. 3149231. 315 914 3159573. 3163025. 3166479. 3169936. 3173395. 3176856. 3180320. 3183786. 318 915 3194199. 3197674. 3201152. 3204632. 3208115. 3211600. 3215087. 3218577. 322 916 3229060. 3232559. 3236061. 3239564. 3243071. 3246579. 3250090. 3253603. 325 917 3264157. 3267679. 3271205. 3274732. 3278262. 3281794. 3285328. 3288865. 329 918 3299490. 3303036. 3306585. 3310135. 3313689. 3317245. 3320803. 3324363. 332 919 3335058. 3338628. 3342200. 3345775. 3349352. 3352931. 3356513. 3360097. 336 920 3370863. 3374456. 3378052. 3381650. 3385250. 3388852. 3392457. 3396064. 339 921 3406899. 3410515. 3414133. 3417754. 3421377. 3425003. 3428630. 3432260. 343 922 3443163. 3446802. 3450443. 3454087. 3457733. 3461381. 3465031. 3468684. 347 923 3479655. 3483317. 3486982. 3490648. 3494317. 3497987. 3501661. 3505336. 350 924 3516376. 3520061. 3523748. 3527437. 3531128. 3534822. 3538518. 3542216. 354
21

 2001 LAKE MEAD - BOULDER CITY, NEVADA (A 2001 AREA-CAPACITY TABLES  THE CAPACITY TABLE IS IN ACRE FEET THE ELEVATION INCREMENT IS  ELEV. FEET 0 .1 .2 .3 .4 .5 .6 .7  925 3553325. 3557032. 3560742. 3564454. 3568168. 3571885. 3575604. 3579325. 358 926 3590502. 3594232. 3597965. 3601699. 3605436. 3609176. 3612917. 3616661. 362 927 3627907. 3631660. 3635415. 3639173. 3642933. 3646695. 3650459. 3654226. 365 928 3665540. 3669316. 3673094. 3676874. 3680657. 3684442. 3688229. 3692019. 369 929 3703401. 3707199. 3711001. 3714804. 3718609. 3722417. 3726227. 3730039. 373 930 3741490. 3745312. 3749135. 3752962. 3756791. 3760621. 3764454. 3768290. 377 931 3779810. 3783655. 3787502. 3791351. 3795203. 3799057. 3802913. 3806772. 381 932 3818362. 3822230. 3826100. 3829973. 3833847. 3837725. 3841604. 3845487. 384 933 3857146. 3861037. 3864931. 3868826. 3872725. 3876625. 3880528. 3884433. 388 934 3896162. 3900077. 3903994. 3907913. 3911834. 3915758. 3919684. 3923612. 392 935 3935411. 3939349. 3943289. 3947231. 3951175. 3955123. 3959072. 3963023. 396 936 3974892. 3978853. 3982816. 3986782. 3990750. 3994720. 3998692. 4002667. 400 937 4014606. 4018590. 4022576. 4026565. 4030556. 4034550. 4038545. 4042543. 404 938 4054551. 4058559. 4062568. 4066580. 4070595. 4074611. 4078631. 4082652. 408 939 4094730. 4098760. 4102793. 4106828. 4110866. 4114906. 4118948. 4122992. 412 940 4135140. 4139194. 4143250. 4147308. 4151369. 4155432. 4159498. 4163566. 416 941 4175783. 4179861. 4183940. 4188023. 4192107. 4196193. 4200282. 4204374. 420 942 4216662. 4220762. 4224865. 4228971. 4233078. 4237188. 4241301. 4245415. 424 943 4257774. 4261898. 4266024. 4270153. 4274284. 4278418. 4282553. 4286692. 429 944 4299120. 4303268. 4307417. 4311570. 4315724. 4319881. 4324040. 4328202. 433 945 4340701. 4344872. 4349045. 4353221. 4357399. 4361579. 4365762. 4369947. 437 946 4382516. 4386710. 4390907. 4395106. 4399307. 4403511. 4407717. 4411925. 441 947 4424565. 4428782. 4433003. 4437225. 4441450. 4445677. 4449907. 4454138. 445 948 4466848. 4471089. 4475333. 4479579. 4483827. 4488077. 4492330. 4496586. 450 949 4509366. 4513630. 4517897. 4522166. 4526438. 4530712. 4534988. 4539267. 454 950 4552117. 4556405. 4560696. 4564990. 4569286. 4573584. 4577885. 4582189. 458 951 4595116. 4599430. 4603747. 4608066. 4612388. 4616712. 4621039. 4625369. 462 952 4638374. 4642714. 4647056. 4651401. 4655749. 4660100. 4664453. 4668808. 467 953 4681890. 4686256. 4690625. 4694996. 4699370. 4703746. 4708125. 4712507. 471 954 4725667. 4730058. 4734453. 4738850. 4743250. 4747652. 4752057. 4756464. 476 955 4769702. 4774120. 4778540. 4782963. 4787389. 4791817. 4796247. 4800681. 480 956 4813996. 4818440. 4822886. 4827335. 4831787. 4836241. 4840698. 4845157. 484 957 4858550. 4863020. 4867492. 4871967. 4876444. 4880924. 4885407. 4889892. 489 958 4903363. 4907859. 4912357. 4916857. 4921361. 4925867. 4930375. 4934886. 493 959 4948435. 4952957. 4957481. 4962007. 4966537. 4971068. 4975603. 4980140. 498 960 4993767. 4998314. 5002864. 5007416. 5011970. 5016527. 5021086. 5025648. 503 961 5039347. 5043918. 5048492. 5053068. 5057646. 5062227. 5066810. 5071395. 507 962 5085166. 5089761. 5094358. 5098958. 5103560. 5108165. 5112772. 5117381. 512 963 5131223. 5135842. 5140463. 5145087. 5149713. 5154341. 5158972. 5163605. 516 964 5177519. 5182162. 5186807. 5191454. 5196104. 5200757. 5205411. 5210068. 521
2001 Lake Mead Sedimentation Survey 

22

 2001 LAKE MEAD - BOULDER CITY, NEVADA (A 2001 AREA-CAPACITY TABLES  THE CAPACITY TABLE IS IN ACRE FEET THE ELEVATION INCREMENT IS  ELEV. FEET 0 .1 .2 .3 .4 .5 .6 .7  965 5224054. 5228720. 5233389. 5238060. 5242734. 5247410. 5252089. 5256770. 526 966 5270827. 5275517. 5280210. 5284905. 5289603. 5294303. 5299005. 5303710. 530 967 5317838. 5322553. 5327269. 5331988. 5336710. 5341433. 5346160. 5350888. 535 968 5365088. 5369827. 5374567. 5379310. 5384055. 5388803. 5393554. 5398306. 540 969 5412578. 5417339. 5422103. 5426870. 5431639. 5436410. 5441185. 5445961. 545 970 5460304. 5465090. 5469879. 5474670. 5479464. 5484261. 5489060. 5493862. 549 971 5508285. 5513098. 5517913. 5522731. 5527552. 5532375. 5537202. 5542030. 554 972 5556533. 5561373. 5566215. 5571059. 5575907. 5580758. 5585610. 5590466. 559 973 5605049. 5609916. 5614785. 5619656. 5624531. 5629408. 5634288. 5639170. 564 974 5653833. 5658726. 5663622. 5668521. 5673422. 5678326. 5683232. 5688141. 569 975 5702885. 5707805. 5712728. 5717653. 5722581. 5727511. 5732445. 5737381. 574 976 5752205. 5757151. 5762101. 5767053. 5772008. 5776965. 5781925. 5786888. 579 977 5801792. 5806766. 5811742. 5816721. 5821702. 5826686. 5831673. 5836663. 584 978 5851647. 5856648. 5861651. 5866656. 5871665. 5876675. 5881689. 5886706. 589 979 5901770. 5906798. 5911827. 5916860. 5921895. 5926933. 5931973. 5937017. 594 980 5952162. 5957215. 5962272. 5967332. 5972395. 5977461. 5982530. 5987602. 599 981 6002835. 6007920. 6013007. 6018096. 6023189. 6028285. 6033384. 6038486. 604 982 6053810. 6058923. 6064040. 6069160. 6074282. 6079409. 6084537. 6089669. 609 983 6105082. 6110226. 6115373. 6120522. 6125676. 6130831. 6135990. 6141152. 614 984 6156655. 6161829. 6167005. 6172185. 6177368. 6182553. 6187742. 6192934. 619 985 6208526. 6213730. 6218937. 6224146. 6229359. 6234574. 6239794. 6245015. 625 986 6260697. 6265930. 6271167. 6276407. 6281650. 6286895. 6292143. 6297395. 630 987 6313167. 6318431. 6323698. 6328967. 6334239. 6339514. 6344793. 6350074. 635 988 6365937. 6371230. 6376527. 6381826. 6387129. 6392434. 6397742. 6403054. 640 989 6419006. 6424329. 6429655. 6434985. 6440317. 6445652. 6450990. 6456332. 646 990 6472374. 6477727. 6483082. 6488442. 6493804. 6499168. 6504536. 6509906. 651 991 6526034. 6531416. 6536801. 6542188. 6547578. 6552972. 6558368. 6563766. 656 992 6579980. 6585391. 6590803. 6596220. 6601639. 6607060. 6612485. 6617913. 662 993 6634212. 6639651. 6645093. 6650537. 6655985. 6661435. 6666888. 6672345. 667 994 6688730. 6694197. 6699667. 6705140. 6710617. 6716095. 6721577. 6727062. 673 995 6743533. 6749029. 6754528. 6760029. 6765534. 6771042. 6776552. 6782065. 678 996 6798621. 6804146. 6809673. 6815203. 6820737. 6826273. 6831811. 6837354. 684 997 6853996. 6859549. 6865106. 6870664. 6876226. 6881790. 6887358. 6892928. 689 998 6909657. 6915238. 6920822. 6926410. 6932000. 6937593. 6943189. 6948788. 695 999 6965602. 6971212. 6976825. 6982441. 6988060. 6993682. 6999306. 7004934. 701 1000 7021833. 7027472. 7033114. 7038760. 7044408. 7050059. 7055714. 7061371. 706 1001 7078362. 7084033. 7089706. 7095382. 7101061. 7106744. 7112429. 7118118. 712 1002 7135202. 7140903. 7146607. 7152314. 7158025. 7163738. 7169455. 7175174. 718 1003 7192352. 7198083. 7203818. 7209557. 7215298. 7221043. 7226790. 7232541. 723 1004 7249811. 7255574. 7261341. 7267110. 7272882. 7278658. 7284436. 7290218. 729
23

 2001 LAKE MEAD - BOULDER CITY, NEVADA (A 2001 AREA-CAPACITY TABLES  THE CAPACITY TABLE IS IN ACRE FEET THE ELEVATION INCREMENT IS  ELEV. FEET 0 .1 .2 .3 .4 .5 .6 .7  1005 7307581. 7313375. 7319172. 7324973. 7330777. 7336582. 7342393. 7348205. 735 1006 7365661. 7371486. 7377314. 7383146. 7388980. 7394818. 7400658. 7406502. 741 1007 7424051. 7429907. 7435766. 7441629. 7447494. 7453363. 7459234. 7465109. 747 1008 7482751. 7488639. 7494529. 7500422. 7506318. 7512218. 7518120. 7524026. 752 1009 7541762. 7547680. 7553602. 7559525. 7565453. 7571383. 7577317. 7583253. 758 1010 7601082. 7607031. 7612983. 7618938. 7624897. 7630858. 7636823. 7642790. 764 1011 7660711. 7666690. 7672673. 7678659. 7684648. 7690639. 7696634. 7702632. 770 1012 7720645. 7726655. 7732668. 7738685. 7744704. 7750726. 7756752. 7762781. 776 1013 7780885. 7786925. 7792969. 7799016. 7805066. 7811119. 7817175. 7823234. 782 1014 7841430. 7847502. 7853576. 7859654. 7865734. 7871818. 7877904. 7883994. 789 1015 7902282. 7908384. 7914489. 7920597. 7926707. 7932822. 7938939. 7945059. 795 1016 7963439. 7969571. 7975707. 7981846. 7987987. 7994132. 8000280. 8006431. 801 1017 8024902. 8031065. 8037231. 8043400. 8049573. 8055748. 8061926. 8068108. 807 1018 8086671. 8092864. 8099061. 8105261. 8111464. 8117670. 8123879. 8130090. 813 1019 8148745. 8154969. 8161197. 8167427. 8173661. 8179897. 8186137. 8192379. 819 1020 8211125. 8217380. 8223638. 8229899. 8236163. 8242430. 8248701. 8254974. 826 1021 8273813. 8280099. 8286387. 8292680. 8298975. 8305273. 8311574. 8317878. 832 1022 8336810. 8343126. 8349446. 8355769. 8362095. 8368424. 8374756. 8381091. 838 1023 8400115. 8406463. 8412814. 8419167. 8425524. 8431884. 8438247. 8444613. 845 1024 8463730. 8470109. 8476490. 8482875. 8489263. 8495653. 8502047. 8508444. 851 1025 8527654. 8534063. 8540476. 8546891. 8553310. 8559732. 8566157. 8572585. 857 1026 8591887. 8598327. 8604771. 8611217. 8617667. 8624119. 8630575. 8637034. 864 1027 8656429. 8662900. 8669374. 8675852. 8682332. 8688816. 8695302. 8701792. 870 1028 8721280. 8727782. 8734287. 8740795. 8747307. 8753821. 8760339. 8766859. 877 1029 8786440. 8792973. 8799509. 8806048. 8812590. 8819136. 8825684. 8832236. 883 1030 8851909. 8858473. 8865040. 8871611. 8878184. 8884761. 8891341. 8897924. 890 1031 8917693. 8924289. 8930889. 8937491. 8944097. 8950706. 8957318. 8963933. 897 1032 8983798. 8990427. 8997058. 9003693. 9010330. 9016971. 9023616. 9030263. 903 1033 9050225. 9056885. 9063548. 9070215. 9076885. 9083558. 9090234. 9096914. 910 1034 9116972. 9123664. 9130360. 9137059. 9143761. 9150466. 9157174. 9163886. 917 1035 9184040. 9190765. 9197492. 9204223. 9210957. 9217695. 9224435. 9231179. 923 1036 9251429. 9258186. 9264946. 9271709. 9278475. 9285245. 9292017. 9298793. 930 1037 9319140. 9325929. 9332720. 9339516. 9346314. 9353115. 9359920. 9366728. 937 1038 9387171. 9393992. 9400816. 9407643. 9414474. 9421307. 9428144. 9434984. 944 1039 9455524. 9462377. 9469233. 9476092. 9482955. 9489820. 9496689. 9503561. 951 1040 9524197. 9531082. 9537971. 9544862. 9551758. 9558656. 9565558. 9572463. 957 1041 9593200. 9600119. 9607041. 9613966. 9620895. 9627828. 9634763. 9641702. 964 1042 9662540. 9669492. 9676448. 9683408. 9690370. 9697336. 9704306. 9711279. 971 1043 9732217. 9739204. 9746193. 9753186. 9760183. 9767183. 9774186. 9781192. 978 1044 9802232. 9809252. 9816276. 9823302. 9830333. 9837366. 9844403. 9851443. 985
2001 Lake Mead Sedimentation Survey 

24

 2001 LAKE MEAD - BOULDER CITY, NEVADA (A 2001 AREA-CAPACITY TABLES  THE CAPACITY TABLE IS IN ACRE FEET THE ELEVATION INCREMENT IS  ELEV. FEET 0 .1 .2 .3 .4 .5 .6 .7  1045 9872584. 9879638. 9886695. 9893756. 9900820. 9907887. 9914958. 9922032. 992 1046 9943274. 9950362. 9957453. 9964547. 9971644. 9978745. 9985850. 9992958. 1000 1047 10014300. 10021420. 10028550. 10035680. 10042810. 10049940. 10057080. 10064220. 1007 1048 10085670. 10092820. 10099980. 10107140. 10114310. 10121470. 10128650. 10135820. 1014 1049 10157370. 10164560. 10171750. 10178940. 10186140. 10193350. 10200550. 10207760. 1021 1050 10229410. 10236620. 10243850. 10251080. 10258310. 10265550. 10272790. 10280040. 1028 1051 10301790. 10309050. 10316310. 10323580. 10330850. 10338120. 10345400. 10352680. 1035 1052 10374550. 10381840. 10389140. 10396440. 10403750. 10411060. 10418370. 10425690. 1043 1053 10447660. 10455000. 10462330. 10469670. 10477010. 10484360. 10491710. 10499060. 1050 1054 10521140. 10528510. 10535880. 10543260. 10550640. 10558020. 10565410. 10572790. 1058 1055 10594990. 10602390. 10609800. 10617210. 10624620. 10632040. 10639460. 10646890. 1065 1056 10669190. 10676630. 10684070. 10691520. 10698970. 10706430. 10713880. 10721350. 1072 1057 10743750. 10751230. 10758710. 10766190. 10773680. 10781170. 10788670. 10796160. 1080 1058 10818680. 10826190. 10833710. 10841230. 10848750. 10856280. 10863810. 10871350. 1087 1059 10893970. 10901520. 10909070. 10916630. 10924190. 10931750. 10939320. 10946890. 1095 1060 10969620. 10977200. 10984790. 10992390. 10999980. 11007580. 11015180. 11022790. 1103 1061 11045630. 11053250. 11060880. 11068510. 11076140. 11083780. 11091420. 11099060. 1110 1062 11122010. 11129670. 11137330. 11144990. 11152660. 11160330. 11168010. 11175690. 1118 1063 11198750. 11206440. 11214140. 11221840. 11229540. 11237250. 11244960. 11252680. 1126 1064 11275840. 11283570. 11291310. 11299040. 11306780. 11314530. 11322280. 11330030. 1133 1065 11353300. 11361070. 11368840. 11376610. 11384390. 11392170. 11399950. 11407740. 1141 1066 11431130. 11438930. 11446740. 11454540. 11462360. 11470170. 11477990. 11485820. 1149 1067 11509310. 11517150. 11524990. 11532840. 11540690. 11548540. 11556400. 11564260. 1157 1068 11587860. 11595730. 11603610. 11611490. 11619380. 11627270. 11635160. 11643060. 1165 1069 11666770. 11674680. 11682590. 11690510. 11698430. 11706360. 11714290. 11722220. 1173 1070 11746040. 11753970. 11761920. 11769880. 11777830. 11785800. 11793760. 11801720. 1180 1071 11825650. 11833630. 11841610. 11849600. 11857590. 11865580. 11873580. 11881580. 1188 1072 11905600. 11913620. 11921640. 11929660. 11937680. 11945710. 11953740. 11961780. 1196 1073 11985900. 11993950. 12002000. 12010050. 12018120. 12026180. 12034240. 12042310. 1205 1074 12066540. 12074620. 12082710. 12090800. 12098890. 12106980. 12115080. 12123190. 1213 1075 12147520. 12155630. 12163750. 12171880. 12180000. 12188130. 12196270. 12204400. 1221 1076 12228830. 12236980. 12245140. 12253300. 12261460. 12269620. 12277790. 12285960. 1229 1077 12310490. 12318680. 12326860. 12335060. 12343250. 12351450. 12359650. 12367860. 1237 1078 12392490. 12400710. 12408930. 12417160. 12425390. 12433620. 12441850. 12450090. 1245 1079 12474830. 12483080. 12491340. 12499600. 12507860. 12516130. 12524400. 12532670. 1254 1080 12557510. 12565800. 12574090. 12582380. 12590680. 12598980. 12607280. 12615590. 1262 1081 12640530. 12648850. 12657180. 12665510. 12673840. 12682180. 12690520. 12698860. 1270 1082 12723910. 12732270. 12740630. 12748990. 12757360. 12765730. 12774100. 12782480. 1279 1083 12807630. 12816030. 12824420. 12832820. 12841220. 12849630. 12858040. 12866450. 1287 1084 12891710. 12900140. 12908570. 12917000. 12925440. 12933880. 12942330. 12950770. 1295
25

 2001 LAKE MEAD - BOULDER CITY, NEVADA (A 2001 AREA-CAPACITY TABLES  THE CAPACITY TABLE IS IN ACRE FEET THE ELEVATION INCREMENT IS  ELEV. FEET 0 .1 .2 .3 .4 .5 .6 .7  1085 12976140. 12984600. 12993070. 13001540. 13010010. 13018480. 13026960. 13035450. 1304 1086 13060920. 13069420. 13077920. 13086420. 13094930. 13103440. 13111960. 13120470. 1312 1087 13146050. 13154580. 13163120. 13171660. 13180200. 13188750. 13197300. 13205850. 1321 1088 13231530. 13240100. 13248670. 13257240. 13265820. 13274400. 13282990. 13291580. 1330 1089 13317360. 13325960. 13334570. 13343180. 13351790. 13360410. 13369030. 13377650. 1338 1090 13403540. 13412180. 13420820. 13429470. 13438120. 13446770. 13455420. 13464080. 1347 1091 13490080. 13498750. 13507420. 13516100. 13524790. 13533470. 13542160. 13550850. 1355 1092 13576950. 13585660. 13594370. 13603080. 13611800. 13620520. 13629240. 13637970. 1364 1093 13664170. 13672910. 13681660. 13690410. 13699160. 13707910. 13716670. 13725430. 1373 1094 13751740. 13760520. 13769300. 13778080. 13786870. 13795650. 13804450. 13813240. 1382 1095 13839650. 13848460. 13857280. 13866100. 13874920. 13883740. 13892570. 13901400. 1391 1096 13927910. 13936760. 13945610. 13954460. 13963310. 13972170. 13981030. 13989900. 1399 1097 14016520. 14025400. 14034280. 14043170. 14052060. 14060950. 14069850. 14078750. 1408 1098 14105470. 14114380. 14123300. 14132220. 14141140. 14150070. 14159000. 14167940. 1417 1099 14194760. 14203710. 14212660. 14221620. 14230580. 14239540. 14248510. 14257480. 1426 1100 14284400. 14293390. 14302370. 14311370. 14320360. 14329360. 14338370. 14347370. 1435 1101 14374420. 14383440. 14392470. 14401500. 14410540. 14419580. 14428620. 14437670. 1444 1102 14464840. 14473910. 14482970. 14492050. 14501120. 14510200. 14519290. 14528380. 1453 1103 14555670. 14564770. 14573880. 14582990. 14592110. 14601230. 14610360. 14619490. 1462 1104 14646900. 14656040. 14665190. 14674350. 14683500. 14692660. 14701830. 14711000. 1472 1105 14738530. 14747720. 14756910. 14766100. 14775300. 14784500. 14793710. 14802920. 1481 1106 14830570. 14839800. 14849030. 14858260. 14867500. 14876740. 14885990. 14895240. 1490 1107 14923010. 14932280. 14941550. 14950830. 14960110. 14969390. 14978680. 14987970. 1499 1108 15015860. 15025170. 15034480. 15043800. 15053120. 15062440. 15071770. 15081100. 1509 1109 15109120. 15118460. 15127820. 15137170. 15146530. 15155900. 15165260. 15174640. 1518 1110 15202770. 15212150. 15221540. 15230940. 15240340. 15249740. 15259150. 15268560. 1527 1111 15296820. 15306250. 15315680. 15325120. 15334550. 15344000. 15353440. 15362890. 1537 1112 15391270. 15400730. 15410200. 15419680. 15429160. 15438640. 15448120. 15457610. 1546 1113 15486100. 15495600. 15505110. 15514620. 15524140. 15533660. 15543180. 15552710. 1556 1114 15581320. 15590860. 15600410. 15609960. 15619510. 15629070. 15638630. 15648200. 1565 1115 15676920. 15686500. 15696090. 15705680. 15715270. 15724870. 15734470. 15744080. 1575 1116 15772910. 15782530. 15792160. 15801790. 15811420. 15821050. 15830690. 15840340. 1584 1117 15869290. 15878950. 15888610. 15898280. 15907950. 15917630. 15927300. 15936990. 1594 1118 15966060. 15975750. 15985460. 15995160. 16004870. 16014580. 16024300. 16034020. 1604 1119 16063210. 16072940. 16082680. 16092430. 16102180. 16111930. 16121680. 16131440. 1614 1120 16160740. 16170520. 16180300. 16190080. 16199870. 16209660. 16219450. 16229250. 1623 1121 16258670. 16268480. 16278300. 16288120. 16297950. 16307780. 16317610. 16327440. 1633 1122 16356980. 16366830. 16376690. 16386550. 16396410. 16406280. 16416150. 16426030. 1643 1123 16455680. 16465570. 16475460. 16485360. 16495260. 16505170. 16515080. 16524990. 1653 1124 16554760. 16564690. 16574620. 16584560. 16594500. 16604450. 16614390. 16624350. 1663
2001 Lake Mead Sedimentation Survey 

26

 2001 LAKE MEAD - BOULDER CITY, NEVADA (A 2001 AREA-CAPACITY TABLES  THE CAPACITY TABLE IS IN ACRE FEET THE ELEVATION INCREMENT IS  ELEV. FEET 0 .1 .2 .3 .4 .5 .6 .7  1125 16654230. 16664200. 16674170. 16684150. 16694120. 16704110. 16714100. 16724090. 1673 1126 16754080. 16764090. 16774100. 16784120. 16794140. 16804160. 16814180. 16824210. 1683 1127 16854330. 16864370. 16874420. 16884480. 16894530. 16904590. 16914660. 16924730. 1693 1128 16954960. 16965040. 16975130. 16985220. 16995320. 17005420. 17015520. 17025630. 1703 1129 17055970. 17066100. 17076220. 17086350. 17096490. 17106630. 17116770. 17126910. 1713 1130 17157370. 17167530. 17177690. 17187860. 17198030. 17208210. 17218390. 17228580. 1723 1131 17259170. 17269370. 17279580. 17289790. 17300010. 17310230. 17320450. 17330680. 1734 1132 17361390. 17371640. 17381890. 17392140. 17402400. 17412660. 17422930. 17433200. 1744 1133 17464040. 17474330. 17484620. 17494920. 17505220. 17515520. 17525830. 17536150. 1754 1134 17567110. 17577440. 17587780. 17598120. 17608460. 17618810. 17629160. 17639510. 1764 1135 17670610. 17680980. 17691360. 17701740. 17712120. 17722510. 17732910. 17743310. 1775 1136 17774530. 17784940. 17795360. 17805780. 17816210. 17826640. 17837080. 17847520. 1785 1137 17878870. 17889330. 17899790. 17910250. 17920720. 17931200. 17941680. 17952160. 1796 1138 17983630. 17994130. 18004640. 18015150. 18025660. 18036180. 18046700. 18057220. 1806 1139 18088820. 18099360. 18109910. 18120460. 18131020. 18141580. 18152140. 18162710. 1817 1140 18194440. 18205020. 18215610. 18226210. 18236810. 18247410. 18258020. 18268640. 1827 1141 18300520. 18311160. 18321800. 18332450. 18343100. 18353760. 18364420. 18375090. 1838 1142 18407130. 18417820. 18428520. 18439220. 18449920. 18460630. 18471350. 18482070. 1849 1143 18514260. 18525000. 18535750. 18546500. 18557260. 18568020. 18578790. 18589570. 1860 1144 18621920. 18632710. 18643510. 18654320. 18665130. 18675940. 18686760. 18697590. 1870 1145 18730100. 18740940. 18751790. 18762650. 18773510. 18784380. 18795250. 18806130. 1881 1146 18838800. 18849700. 18860600. 18871510. 18882430. 18893340. 18904270. 18915200. 1892 1147 18948020. 18958970. 18969930. 18980890. 18991860. 19002830. 19013810. 19024790. 1903 1148 19057770. 19068770. 19079780. 19090800. 19101820. 19112840. 19123870. 19134910. 1914 1149 19168040. 19179100. 19190160. 19201230. 19212300. 19223370. 19234460. 19245540. 1925 1150 19278840. 19289950. 19301060. 19312180. 19323300. 19334420. 19345550. 19356690. 1936 1151 19390120. 19401280. 19412440. 19423600. 19434770. 19445940. 19457120. 19468300. 1947 1152 19501870. 19513070. 19524280. 19535490. 19546700. 19557920. 19569140. 19580370. 1959 1153 19614090. 19625330. 19636580. 19647840. 19659100. 19670360. 19681630. 19692910. 1970 1154 19726760. 19738050. 19749350. 19760650. 19771960. 19783270. 19794590. 19805910. 1981 1155 19839900. 19851240. 19862580. 19873930. 19885280. 19896640. 19908000. 19919370. 1993 1156 19953500. 19964880. 19976270. 19987670. 19999070. 20010470. 20021880. 20033290. 2004 1157 20067560. 20078990. 20090430. 20101870. 20113320. 20124770. 20136220. 20147680. 2015 1158 20182090. 20193560. 20205050. 20216530. 20228030. 20239520. 20251020. 20262530. 2027 1159 20297070. 20308600. 20320130. 20331660. 20343200. 20354740. 20366290. 20377840. 2038 1160 20412530. 20424100. 20435670. 20447250. 20458840. 20470430. 20482020. 20493620. 2050 1161 20528440. 20540060. 20551680. 20563300. 20574940. 20586570. 20598210. 20609860. 2062 1162 20644820. 20656480. 20668150. 20679820. 20691500. 20703180. 20714860. 20726560. 2073 1163 20761660. 20773370. 20785080. 20796800. 20808520. 20820250. 20831980. 20843720. 2085 1164 20878960. 20890710. 20902470. 20914240. 20926010. 20937780. 20949560. 20961350. 2097
27

 2001 LAKE MEAD - BOULDER CITY, NEVADA (A 2001 AREA-CAPACITY TABLES  THE CAPACITY TABLE IS IN ACRE FEET THE ELEVATION INCREMENT IS  ELEV. FEET 0 .1 .2 .3 .4 .5 .6 .7  1165 20996720. 21008530. 21020330. 21032140. 21043960. 21055780. 21067600. 21079430. 2109 1166 21114950. 21126800. 21138650. 21150510. 21162370. 21174240. 21186110. 21197990. 2120 1167 21233640. 21245540. 21257440. 21269340. 21281250. 21293160. 21305080. 21317000. 2132 1168 21352800. 21364740. 21376680. 21388630. 21400590. 21412550. 21424510. 21436480. 2144 1169 21472410. 21484400. 21496390. 21508390. 21520390. 21532390. 21544400. 21556420. 2156 1170 21592490. 21604530. 21616570. 21628610. 21640670. 21652730. 21664790. 21676870. 2168 1171 21713120. 21725220. 21737320. 21749430. 21761550. 21773670. 21785800. 21797940. 2181 1172 21834380. 21846550. 21858710. 21870890. 21883070. 21895260. 21907450. 21919650. 2193 1173 21956280. 21968510. 21980740. 21992980. 22005220. 22017470. 22029730. 22041990. 2205 1174 22078820. 22091110. 22103400. 22115700. 22128010. 22140320. 22152650. 22164970. 2217 1175 22201990. 22214340. 22226700. 22239060. 22251430. 22263810. 22276200. 22288590. 2230 1176 22325790. 22338210. 22350630. 22363060. 22375490. 22387930. 22400380. 22412830. 2242 1177 22450230. 22462710. 22475200. 22487690. 22500190. 22512690. 22525200. 22537720. 2255 1178 22575310. 22587850. 22600400. 22612960. 22625520. 22638090. 22650660. 22663240. 2267 1179 22701020. 22713630. 22726240. 22738860. 22751480. 22764110. 22776750. 22789400. 2280 1180 22827370. 22840040. 22852720. 22865400. 22878100. 22890810. 22903520. 22916250. 2292 1181 22954470. 22967230. 22980000. 22992780. 23005570. 23018360. 23031170. 23043980. 2305 1182 23082470. 23095320. 23108180. 23121040. 23133920. 23146800. 23159700. 23172600. 2318 1183 23211360. 23224300. 23237240. 23250200. 23263160. 23276130. 23289120. 23302110. 2331 1184 23341130. 23354160. 23367200. 23380240. 23393290. 23406350. 23419430. 23432510. 2344 1185 23471800. 23484920. 23498040. 23511170. 23524310. 23537460. 23550620. 23563790. 2357 1186 23603350. 23616560. 23629770. 23642990. 23656220. 23669460. 23682710. 23695970. 2370 1187 23735800. 23749090. 23762390. 23775700. 23789020. 23802350. 23815690. 23829030. 2384 1188 23869130. 23882510. 23895900. 23909300. 23922710. 23936130. 23949560. 23962990. 2397 1189 24003350. 24016820. 24030300. 24043790. 24057290. 24070790. 24084310. 24097830. 2411 1190 24138460. 24152020. 24165590. 24179160. 24192740. 24206340. 24219930. 24233540. 2424 1191 24274410. 24288050. 24301700. 24315360. 24329020. 24342690. 24356370. 24370060. 2438 1192 24411170. 24424890. 24438620. 24452350. 24466100. 24479850. 24493610. 24507380. 2452 1193 24548730. 24562530. 24576330. 24590150. 24603970. 24617800. 24631650. 24645490. 2465 1194 24687080. 24700960. 24714850. 24728750. 24742650. 24756560. 24770480. 24784410. 2479 1195 24826240. 24840200. 24854170. 24868150. 24882130. 24896120. 24910120. 24924130. 2493 1196 24966200. 24980240. 24994290. 25008350. 25022410. 25036480. 25050560. 25064650. 2507 1197 25106960. 25121080. 25135210. 25149350. 25163490. 25177640. 25191800. 25205970. 2522 1198 25248520. 25262730. 25276930. 25291150. 25305370. 25319600. 25333850. 25348090. 2536 1199 25390890. 25405170. 25419450. 25433750. 25448050. 25462370. 25476690. 25491020. 2550 1200 25534050. 25548410. 25562780. 25577150. 25591530. 25605920. 25620320. 25634720. 2564 1201 25677980. 25692410. 25706850. 25721300. 25735760. 25750220. 25764690. 25779170. 2579 1202 25822650. 25837150. 25851670. 25866190. 25880720. 25895260. 25909800. 25924350. 2593 1203 25968050. 25982630. 25997210. 26011810. 26026410. 26041020. 26055640. 26070270. 2608 1204 26114190. 26128840. 26143500. 26158170. 26172850. 26187530. 26202220. 26216920. 2623
2001 Lake Mead Sedimentation Survey 

28

 2001 LAKE MEAD - BOULDER CITY, NEVADA (A 2001 AREA-CAPACITY TABLES  THE CAPACITY TABLE IS IN ACRE FEET THE ELEVATION INCREMENT IS  ELEV. FEET 0 .1 .2 .3 .4 .5 .6 .7  1205 26261060. 26275790. 26290520. 26305260. 26320010. 26334770. 26349540. 26364310. 2637 1206 26408670. 26423470. 26438280. 26453090. 26467920. 26482750. 26497590. 26512430. 2652 1207 26557010. 26571890. 26586770. 26601660. 26616560. 26631460. 26646370. 26661290. 2667 1208 26706090. 26721040. 26736000. 26750960. 26765930. 26780910. 26795890. 26810890. 2682 1209 26855910. 26870930. 26885960. 26901000. 26916040. 26931090. 26946150. 26961220. 2697 1210 27006460. 27021560. 27036650. 27051760. 27066870. 27081990. 27097110. 27112240. 2712 1211 27157660. 27172810. 27187960. 27203120. 27218290. 27233460. 27248640. 27263830. 2727 1212 27309410. 27324610. 27339830. 27355040. 27370270. 27385500. 27400730. 27415970. 2743 1213 27461720. 27476980. 27492240. 27507520. 27522800. 27538080. 27553370. 27568660. 2758 1214 27614580. 27629900. 27645220. 27660550. 27675880. 27691220. 27706570. 27721910. 2773 1215 27768000. 27783370. 27798750. 27814130. 27829520. 27844920. 27860320. 27875720. 2789 1216 27921970. 27937400. 27952830. 27968270. 27983720. 27999170. 28014620. 28030090. 2804 1217 28076500. 28091980. 28107470. 28122970. 28138470. 28153970. 28169480. 28185000. 2820 1218 28231580. 28247120. 28262670. 28278220. 28293770. 28309340. 28324900. 28340470. 2835 1219 28387220. 28402820. 28418420. 28434020. 28449640. 28465250. 28480870. 28496500. 2851 1220 28543420. 28559070. 28574730. 28590390. 28606060. 28621740. 28637430. 28653110. 2866 1221 28700230. 28715950. 28731670. 28747400. 28763140. 28778890. 28794640. 28810400. 2882 1222 28857720. 28873500. 28889290. 28905090. 28920900. 28936710. 28952530. 28968360. 2898 1223 29015880. 29031730. 29047590. 29063450. 29079330. 29095210. 29111100. 29126990. 2914 1224 29174710. 29190630. 29206560. 29222490. 29238430. 29254380. 29270340. 29286300. 2930 1225 29334220. 29350210. 29366210. 29382210. 29398220. 29414230. 29430250. 29446280. 2946 1226 29494410. 29510460. 29526530. 29542600. 29558670. 29574750. 29590840. 29606940. 2962 1227 29655270. 29671390. 29687520. 29703660. 29719800. 29735950. 29752110. 29768270. 2978 1228 29816800. 29832990. 29849190. 29865400. 29881610. 29897830. 29914050. 29930280. 2994 1229 29979010. 29995270. 30011540. 30027810. 30044090. 30060380. 30076670. 30092960. 3010 1230 30141900. 

Appendix VII 
1
The 2001 Lake Mead Bathymetry 

Study 

Lower Colorado Regional Office 

L.C. Region GIS Group 

Boulder City, Nevada 

September 2003
1

2001 Lake Mead Bathymetry Study 

Introduction 

The Bureau of Reclamation (Reclamation) surveyed Lake Mead Reservoir in 

2001 in order to develop a present day storage-elevation relationships. The major 

objective of the field collection was to map the areas of sediment accumulation 

since closure of Hoover Dam in February of 1935. The primary objective for 

conducting the reservoir survey was to measure the current reservoir areacapacity. The collected data can also be used to determine: 

storage depletion caused by sediment deposition since closure of the dam 

annual sediment yield rates 

current location of sediment deposition 

current reservoir topography 

economic life of the reservoir 

Previous sedimentation surveys of Lake Mead completed in 1948 and 1963, 

utilized the range line collection method. The 1963 survey generated new 

reservoir topography from range lines that were collected from 300 to 400 meters 

apart. Results of these collections measured the vast majority of the sediments as 

a flat bottom deposit within the original river channel geometry. A 1999 

University of Nevada and USGS sidescan sonar survey of the lower portion of 

Lake Mead found the accumulation of sediments to be restricted to the original 

river beds of the Colorado River and Las Vegas Creek and also to be flat-lying.4 

This situation was also found during the 1986 Lake Powell survey that measured 

the majority of sediment deposits within the original channel geometry and to be 

flat in nature.5 Utilizing these previous survey results, and working within the 

available budget for conducting the Lake Mead survey, the 2001 collection focus 

the measurements around the original river channel areas. 

 

4 Surficial Geology and Distribution of Post-Impoundment Sediment of the Western Park of Lake 

Mead Based on a Sidescan Sonar and High-Resolution Seismic-Reflection Survey, Open-File 

Report 99-581, University of Nevada at Las Vegas and U.S. Geological Survey. 

5 1986 Lake Powell Survey, REC-ERC-88-6, USBR. 
2001 Lake Mead Sedimentation Survey 

2

Data Collection 

The 2001 survey utilized a high resolution multibeam mapping system for 

collecting x,y,z data of the Lake Mead bottom from depths of 3 meters in the 

upper portions of the lake to greater than 140 meters near Hoover Dam. The 

system consisted of a single transducer that was mounted on the center bow or 

forward portion of the boat . From the single transducer a fan array of narrow 

beams generated a detailed cross section of bottom geometry as the survey vessel 

passed over the areas to be mapped. The system used for this survey transmitted 

80 separate 1 1⁄2 degree slant beams resulting in a 120-degree swath from the 

transducer (Figure 1). 

Figure 1 

The system operates at 200 kHz and can generate up to 30 profiles per second. 

The bottom area covered by the swath is dependant on the depth of the water 

column, which for Lake Mead were at times up to 500 meters of the lake bottom 

being mapped by an individual sweep. The multibeam system could have been 

used to obtain 100% underwater bottom coverage, but much greater time and 

budget would have been required for data collection and analysis. 

The multibeam system was composed of several instruments all in 

communication with a central on-board computer that utilized the latest version of 

collection and processing software. The components included: 

• GPS for positioning 

Note: RTK GPS techniques were used for the lower portion of the 

reservoir, from the dam upstream to the upper portion of the narrows. 

Stationary position accuracies of up to 1 to 2 centimeters are possible. 

This system requires the establishment of a local base station, and 

maintaining constant communication between the base and survey vessel 

receivers. 

Note: The upper portion of the reservoir above the narrows was surveyed 

using a “precise positioning service” which requires DOD authorization. 
3

The stationary position accuracies are around +4 meters. This system was 

utilized to significantly reduce the collection time. The resulting lower 

accuracies were determined to be insignificant when measuring the 

location of the flat lying sediments. 

• Motion reference unit (MRU) - measures the heave, pitch, and roll 

of the survey vessel during collection. 

• Gyro - measures the yaw or vessel attitude. 

With a proper calibration, the collection and data processing software utilizes all 

incoming information to provide a detailed x,y,z data set of the lake bottom. 

The multibeam hydrographic survey system was mounted in the cabin of a 24-

foot trihull aluminum vessel equipped with twin in-board motors and an on-board 

generator for power to the equipment. The multibeam system was installed, 

tested, and training was conducted in February of 2001 near Hoover Dam. The 

collection of underwater data on Lake Mead was conducted during a 2-week and 

3-week period beginning in March and concluding in May of 2001. The areas 

covered included the underwater river channels of Las Vegas and Overton arms, 

and the Colorado River channel from the dam to just downstream of Pearce Ferry. 

The boat and system were operated by 2-person crews that consisted of personnel 

from Reclamation’s Denver and Boulder City offices. For the deeper portions of 

the reservoir, the procedure included running parallel survey lines whose 

alignment was somewhat longitudinal with the original river channel alignment. 

The distance between the parallel survey lines was depth dependent and was set to 

provide some overlap of the data sweeps. Enough parallel survey lines were run to 

ensure that complete mapping of the deposited sediments would be obtained. As 

the survey vessels mapped the shallow water areas in the upper reaches of the 

reservoir the overlapping of the data sweeps was abandoned due to the time it 

would have taken to ensure full coverage. As previously stated, the sediments 

were found to be flat lying so it was determined that the areas missed could be 

projected during final analysis. 

Data collection areas were developed to provide data sets that were manageable 

for both collection and analysis. Figure 2 shows the extent of the 56 data sets 

collected in the 2001 bathymetry study. 
2001 Lake Mead Sedimentation Survey 

4

Data Analysis 

The first part of the analysis started with the processing of all the collected raw 

profile files of the bottom. This included applying all necessary correction 

information that was collected such as vessel location and the roll, pitch, and yaw 

effects on the survey vessel. Other corrections included applying the sound 

velocity and converting all depth data points to elevations. All elevations in the 

final analysis were tied to the measured water surface elevation at the time of 

collection. To be able to accomplish the analysis filtering of data was completed 

due to the massive amount of information that was collected by the multibeam 

system (Over 20 million data points were collected in the 2001 study). This was 

accomplished by filtering the data into 5-meter grids or cells and saving one 

sounding per cell. Quality control of the data set was accomplished by 

conducting field calibration as required by the multibeam system and collecting 

velocity profile data for the areas being surveyed. 

The second part of the analysis consisted of building lake bottom surfaces based 

on the filtered data from the first step. This analysis was conducted utilizing the 

areas and sheet boundaries as defined in previous Lake Mead Surveys. The 

boundaries for the areas and the sheets are shown in Figures 3 and 4 respectively. 
5
2001 Lake Mead Sedimentation Survey 

6

The analysis of the 2001 bathymetric data first required the generation of the 1935 

surface (also known as the original surface). Once the original surface was 

developed,6 the data collected in the 2001 survey was overlaid on the original 

surface to produce the 2001 surface. Comparison of the original surface and the 

2001 surface provided the quantity and location of sediment that has been 

deposited in Lake Mead since the construction of Hoover Dam. 

All data was collected and processed in UTM Zone 11 North, NAD 83 coordinate 

system. 

Generation of the 1935 surfaces: 

The USGS 10 Meter Lake Mead Underwater DEMs were used to generate 10 

Meter contours for the entire lake. This was completed using the Contour 

command from 3-D Analyst in Arc Map. The resulting coverage was called 

usgscon_83. 

 

The 375 meter (1230 foot) contour was created using the USGS 10 Meter Lake 

Mead Underwater DEMs. This represented the high water mark for the entire 

lake. This was completed using the Contour command from 3-D Analyst in Arc 

Map. The resulting coverage was called usgscon375_83. (Note that the 1230 foot 

contour was designated as the high water mark for the lake in previous studies.) 

Approximate 2.5 meter contours were developed in the original river channels of 

the Colorado and Virgin Rivers using the USGS 10 Meter Lake Mead Underwater 

DEMs. The contour coverage generated was called extra1_conts. The purpose of 

this coverage will be discussed later. 

A polygon coverage was developed for each individual sheet identified in the 

1963 study. This was done using Arc Info and the coordinates of the sheet corners 

noted on the Lake Mead overview sheet associated with the report. The coverage 

usgscon375_83 was used to define the extent of each sheet. These coverages were 

called asheetxx (for example asheet8 for sheet 8). See Figure 4 for an index of 

sheets. 

 

A polygon coverage was developed for each individual area as identified in the 

1963 study. This was done using Arc Info and the coordinates of the sheet corners 

noted in the report. The coverage usgscon375_83 was used to define the extent of 

each Area. For the 2001 analysis Areas 6 and 7 were not analyzed as they were 

assumed to have filled with sediment, and have no volume capacity. These 

coverages were called cutareax (for example cutarea1 for area 1). 

 

6 Original surfaces created from data received from the USGS Rocky Mountain Data 

Center. 
7

Contour coverages were generated for each individual sheet. This was done using 

the clip command in Arc Toolbox with usgscon_83 and each asheet coverage. 

These coverages were called asheetx_con (for example asheet8_con for the 

contours on sheet 8) 

Contour coverages were generated for each individual area. This was done using 

the clip command in Arc Toolbox with usgscon_83 and each cutarea coverage. 

These coverages were called areax_con (for example area1_con for the contours 

in area 1). 

Surfaces were developed for each individual sheet using the Create Tin command 

in 3-D Analyst with the following components: asheetx_con, (hard line option), 

extra1_conts (hard line option), usgscon375_83 (hard line option) and asheet 

(hard clip option). These surfaces were called asheetx_tin . 

Surfaces were created for each individual area using the Create Tin command in 

3-D Analyst with the following components: areax_con (hard line option), 

extra1_conts (hard line option), usgscon375_83 (hard line option), cutarea (hard 

clip option). These surfaces were called areax_tin. 

The area for 10 foot increments for each sheet was calculated. This was done 

using the Volume command in Arc Info with the option to calculate area and 

volume below the datum. An Arc Macro Language (AML) script was created to 

step through the calculations and create an info table with the area and volume at 

each elevation. Arc Map was used to covert the info table to a dbase database. 

The database was imported into Microsoft Excel and areas in square meters 

converted to areas in acres to match the units in Table 3-3 of the 1963 bathymetry 

study. 

The volume for 10 foot increments for each area was calculated. This was done 

using the Volume command in Arc Info with the option to calculate area and 

volume below the datum. An AML script was created to step through the 

calculations and create an info table with the area and volume at each elevation. 

Arc Map was used to covert the info table to a dbase database. The database was 

imported into Microsoft Excel and volumes in cubic meters converted to volumes 

in acre-feet to match with the units in Table 3-7 of the 1963 bathymetry study. 

Area and volume calculations were completed on the original surface to compare 

to values in the 1963 Lake Mead Survey. Values calculated were consistently 

within 2 percent, and usually much closer to the values published in the 1963 

study. This correlation of values provides a reasonable level of reliability for the 

methods used to perform the analysis for the 2001 survey. 
2001 Lake Mead Sedimentation Survey 

8

Inclusion of Multi-beam data collected in 2001: 

A Visual Basic routine was created to covert the raw X, Y, Z data files into a 

generate file that could be imported into an Arc Info Tin. Each raw data file was 

processed through this routine. 

Tins were created for each data set using the Generate option in the Create Tin 

command in Arc Toolbox. 

Point coverages of each data set were created using the Tin to Cover command in 

Arc Toolbox with the point option. (for example Mead125m_pt) 

Polygon coverages of the extent of each point data were generated by digitizing 

lines around each data set. (Mead125m_bnd, for example). 

The bounding polygons were merged to create a single polygon representing the 

data collection area for 2001. Due to a small gap in the data collection, an 

additional polygon resulted in the upper portion of the Overton Arm. The 

resulting coverage is called Mead_bound. 

Generating the 2001 surfaces. 

The 2001 surface was built using contours from the original surface (for areas 

where data was not collected in 2001) combined with the point coverages from 

the 2001 data. Contours for the 2001 surface were created for each sheet using 

the 1935 contours and the erase command with Mead_bound polygon as the erase 

coverage. The result was a coverage with the contours within the area of data 

collection removed, but the contours outside the area of data collection 

unchanged. The coverages called asheetx_con in the 2001 data set were created. 

The 2001 surfaces for each area were created using the same technique as was 

used for each sheet. Contours for each 2001were developed using the 1935 

contours for the area and the erase command with the Mead_bound polygon as 

the erase coverage. The result is a coverage with the contours within the area of 

data collection removed, but the contours outside the area of data collection 

unchanged. There coverages called areax_con in the 2001 data set were created. 

To build the 2001 surface for each sheet it was necessary to determine which data 

collection set was included within each sheet. Arc Map was used for this 

determination, and the results summarized in Table 1. 
9

Table 1. 

Sheet Number Data Sets Within or Overlapping the Sheet 

Sheet 1-2-3 Vegas45m 

Sheet 4 Over15m Over25m Over35m Over45m Govtwsh5m Mead45m 

Sheet 4 (cont) Mead55m 

Sheet 5 Mead35m Mead45m Over15m 

Sheet 6-7 Mead45m Mead55m Mead65m Mead75m Mead85m Mead95m 

Sheet 8 Dam2m Mead12m Mead25m Mead35m Mead45m 

Sheet 9 Mead85m Mead95m Mead105m 

Sheet 10 Mead125m 

Sheet 11-12 Mead105m Mead115m Mead125m Mead135m Mead145m 

Sheet 17 Echo2m 

Sheet 18 Over15m Over25m 

Sheet 19 Mead135m Mead145m Mead155m Mead165m Over15m Boneli5m 

Sheet 20-21 Boneli5m 

Sheet 22 Over_top 

Sheet 23 Over115m Over125m Over_top 

Sheet 24 Over75m Over8b5m Over95m Over105m Over115m Over125m 

Sheet 25 Over45m Over55m Over65m Over75m Over8b5m Echo2m 

Sheet 26 Over15m Over25m Over35m Over45m 

Sheet 27 Over15m Mead165m Mead175m Mead185m 

Sheet 32 Over_top 

Sheet 34 Mead185m Mead195m 

Sheet 35 Mead195m Mead205m Mead215m Mead225m Burro5m Temp5m 

Sheet 35 (cont) Tempbay5m Trail5m 

Sheet 36 Mead225m Mead235m 

Sheet 37 Mead245m Mead255m Mead265m 

Sheet 38 Mead235m Mead245m Huala5m 

Sheet 40 Mead265m Mead275m Mead285m Mead295m Grand5m 

Sheet 41 Mead265m 
2001 Lake Mead Sedimentation Survey 

10

To build the 2001 surface for each area it was necessary to determine which data 

collection set was included within each area. Arc Map was used for this 

determination, and the results summarized the in Table 2. 

Table 2 

Area Data Sets Within the or overlapping the Area 

Area 1 Dam2m Mead12m Mead25m Mead35m Mead45m Mead55m Mead65m Mead75m Mead85m 

Area 1 (cont) 

Over15m Over25m Over35m Over45m Govtwsh5m 

Area 2 Mead105m Mead115m Mead125m Mead135m Mead145m Mead155m Mead165m Mead175m Mead185m 

Area 2 (cont) 

Over15m Over25m Over35m Over45m Boneli5m 

Area 3a Mead185m Mead195m Mead205m Mead215m Mead225m Burro5m Temp5m Tempbay5m Trail5m 

Area 3b Mead225m Mead235m 

Area 4 Mead235m Mead245m Mead255m Mead265m Mead275m Huala5m 

Area 5 Mead275m Mead285m Mead295m Grand5m 

Area 8a Over45m Over55m Over65m Over75m Over8b5m Over95m Over105m Echo2m 

Area 8b Over105m Over115m Over125m Over_top 

Area X Mead85m Mead95m Mead105m 

Area Y Mead105m 

The surface for each individual sheet was developed using the Create Tin 

command in 3-D Analyst with the following components: asheetx_con, (hard 

line option), usgscon375_83 (hard line option) and asheetx (hard clip option) and 

point coverages for the relevant data sets (points). The output tins wre called 

asheetx_tin tin. 

The surface for each individual area was developed using the Create Tin 

command in 3-D Analyst with the following components: areax_con, (hard line 

option), usgscon375_83 (hard line option) and cutareax (hard clip option) and 

point coverages for the relevant data sets (points) . The output tins were called 

areax_tin tins. 
11

The area for 10 foot increments for each sheet was calculated. This was done 

using the Volume command in Arc Info with the option to calculate area and 

volume below the datum. An AML script was created to step through the 

calculations and create an info table with the area and volume at each elevation. 

Arc Map was used to convert the info table to a dbase database. The database 

was imported into Microsoft Excel and areas in square meters converted to areas 

in acres to match the units in Table 3-3 of the 1963 bathymetry study. The 

results of the area calculations are summarized in Table 3 on the following 

pages. 

The volume for 10 foot increments for each area was calculated. This was done 

using the Volume command in Arc Info with the option to calculate area and 

volume below the datum. An AML script was created to step through the 

calculations and create an info table with the area and volume at each elevation. 

Arc Map was used to covert the info table to a dbase database. The database was 

imported into Microsoft Excel and volumes in cubic meters converted to volumes 

in acre-feet to match the units in Table 3-7 of the 1963 bathymetry study. The 

results of the volume calculations are summarized in Table 4. Also included for 

reference are the volumes for the original 1935 surface as reported in the 1963 

Lake Mead Survey. 

A complete summary of volumes for 1935, 1948, 1963 and 2001 can be found 

in the Microsoft Excel file name Mead_Volumes.xls on the DVD Rom. 

Data Included on the DVD: 

Polygon coverage for Lake Mead Areas Polygon coverage for Lake Mead Sheets 

Line coverage of 375 meter (1230 foot) contour around Lake Mead Data sets for 

1935 

- Contours for each area and sheet 

- 1935 surfaces (also known as the original surfaces) 

Data sets from 2001 

- point coverages for each data set 

- polygon coverage showing extent of each data set 

-2001 surfaces 
2001 Lake Mead Sedimentation Survey 

12

Table 3 

10 Foot Contour Areas in Acres 

Sheet 

No 660 670 680 690 

Elevation 

700 710 720 730 740 

1,2,3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

4 0.00 0.00 0.00 0.00 0.00 0.00 0.00 76.84 269.97 5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 329.28 551.65 

6,7 0.00 0.00 0.00 0.00 0.00 0.00 0.00 46.29 987.44 

8 0.00 0.00 0.00 0.02 0.47 3.90 53.69 897.15 1,339.46 9 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.03 13.16 

10 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

11,12 0.00 0.00 0.00 0.00 0.00 0.03 0.16 0.39 0.67 

14 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 15 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 17 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 18 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 19 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

20,21 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

22 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 23 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 24 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 25 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 26 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 27 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 28 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 30 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 31 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 32 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 33 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 34 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 35 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 36 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 37 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 38 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 39 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 40 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 41 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

42 - 52 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Total 0.00 0.00 0.00 0.02 0.47 3.94 53.87 1,349.98 3,162.35 
13

Table 3 (continued) 

10 Foot Contour Areas in Acres 

Sheet 

No 760 770 780 790 

Elevation 800 810 

820 830 840 

1,2,3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

4 500.83 549.20 587.39 623.41 659.48 703.03 752.02 798.01 845.61 5 850.62 904.43 973.14 1,098.43 1,230.64 1,361.64 1,504.31 1,670.13 1,811.84 

6,7 2,355.17 2,565.14 2,740.22 2,905.14 3,063.96 3,216.72 3,369.35 3,533.64 3,695.57 

8 1,616.86 1,676.60 1,734.08 1,791.60 1,847.54 1,902.93 1,956.91 2,016.28 2,067.31 9 607.48 734.58 765.77 796.79 827.09 858.45 891.20 937.37 977.54 

10 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

11,12 73.08 410.62 1,236.24 1,472.00 1,612.52 1,702.32 1,784.41 1,868.78 1,934.07 

14 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 15 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 17 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 18 0.00 0.00 0.00 0.00 238.17 417.33 560.81 724.76 882.40 19 0.40 1.32 139.87 1,025.85 3,085.51 3,543.35 4,002.76 4,344.40 4,652.05 

20,21 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

22 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 23 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 24 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 25 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 26 0.00 0.00 0.00 0.62 547.91 817.64 950.32 1,009.83 1,085.42 27 0.00 0.00 0.00 3.35 303.19 846.99 1,218.16 1,403.46 1,548.08 28 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 30 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 31 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 32 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 33 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 34 0.00 0.00 0.00 0.00 0.01 0.08 101.14 326.70 352.36 35 0.00 0.00 0.00 0.00 0.00 0.00 0.03 193.19 812.56 36 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.70 1.21 37 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 38 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 39 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 40 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 41 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

42 - 52 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Total 6,004.44 6,841.90 8,176.71 9,717.19 13,415.99 15,370.46 17,091.42 18,827.25 20,666.02 
2001 Lake Mead Sedimentation Survey 

14

Table 3 (continued) - 10 Foot Contour Areas in Acres 

Sheet 

No 860 870 880 890 

Elevation 900 910 

920 930 940 

1,2,3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

4 959.22 1,025.48 1,094.30 1,205.14 1,300.25 1,397.60 1,555.88 1,661.24 1,765.66 5 2,160.76 2,314.55 2,468.43 2,731.72 2,861.72 2,990.02 3,263.06 3,393.21 3,523.61 

6,7 4,039.35 4,189.68 4,333.74 4,568.76 4,713.03 4,859.08 5,118.43 5,278.01 5,415.45 

8 2,194.19 2,245.75 2,296.30 2,375.01 2,427.55 2,477.25 2,548.23 2,596.01 2,645.10 9 1,079.21 1,131.37 1,183.05 1,255.44 1,311.65 1,367.66 1,450.24 1,503.35 1,554.55 

10 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

11,12 2,088.16 2,151.99 2,214.13 2,337.49 2,413.29 2,483.49 2,608.53 2,668.81 2,730.14 

14 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 15 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 17 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 18 1,064.52 1,118.59 1,168.26 1,260.40 1,309.58 1,359.86 1,479.85 1,526.63 1,572.95 19 5,258.81 5,464.75 5,656.53 6,056.46 6,232.11 6,402.19 6,805.17 6,947.34 7,093.55 

20,21 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

22 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 23 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 24 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 25 0.00 0.00 3.56 63.48 130.48 188.96 283.42 452.48 663.65 26 1,332.72 1,500.40 1,661.91 1,854.56 1,989.29 2,116.45 2,305.34 2,414.15 2,512.54 27 1,986.67 2,107.71 2,230.41 2,511.23 2,683.54 2,869.30 3,571.35 3,725.12 3,868.61 28 0.00 0.00 0.00 0.00 0.00 0.00 0.19 0.35 0.53 30 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 31 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 32 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 33 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 34 404.23 428.63 453.42 499.30 534.48 569.09 646.38 694.00 736.32 35 1,633.81 1,768.44 1,895.00 2,092.73 2,228.59 2,361.97 2,577.39 2,720.11 2,863.17 36 173.29 386.12 466.87 505.19 534.03 562.07 602.11 630.00 656.52 37 0.00 0.00 0.00 1.87 3.53 5.51 19.23 154.18 479.79 38 0.60 3.08 59.24 191.93 659.20 1,211.92 1,693.24 1,936.46 2,046.41 39 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 40 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 41 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

42 - 52 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Total 24,375.54 25,836.55 27,185.14 29,510.71 31,332.31 33,222.42 36,528.02 38,301.45 40,128.55 
15

Table 3 (continued) - 10 Foot Contour Areas in Acres 

Sheet 

No 960 970 980 990 

Elevation 1000 1010 

1020 1030 1040 

1,2,3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4.22 30.96 

4 2,060.97 2,186.42 2,317.44 2,536.12 2,689.25 2,853.42 3,218.53 3,417.15 3,599.28 5 3,924.64 4,083.62 4,246.48 4,441.85 4,589.86 4,742.27 4,936.24 5,077.82 5,221.45 

6,7 5,816.81 5,945.12 6,071.09 6,349.90 6,500.98 6,652.95 6,925.50 7,051.77 7,178.92 

8 2,779.50 2,827.39 2,873.19 2,958.52 3,011.98 3,065.01 3,146.17 3,193.76 3,240.55 9 1,684.86 1,738.32 1,791.36 1,876.64 1,937.84 1,998.83 2,087.71 2,143.23 2,198.87 

10 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

11,12 2,943.17 3,011.13 3,079.42 3,275.84 3,347.48 3,418.73 3,576.29 3,645.26 3,714.70 

14 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 15 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 17 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 18 1,737.95 1,787.37 1,836.75 1,984.23 2,042.41 2,098.11 2,243.35 2,297.49 2,351.08 19 7,653.41 7,837.23 8,012.06 8,580.42 8,806.73 9,042.62 9,680.13 9,903.90 10,125.32 

20,21 0.00 0.00 10.34 39.60 61.19 89.37 165.37 206.27 243.86 

22 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 23 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 24 0.00 0.18 198.65 658.15 1,178.64 1,691.55 2,351.22 2,806.86 3,402.45 25 1,417.64 1,904.49 2,131.11 2,361.66 2,523.77 2,684.05 3,005.41 3,171.87 3,340.98 26 2,858.60 2,986.77 3,114.00 3,411.27 3,546.73 3,683.49 4,061.54 4,183.05 4,302.48 27 4,338.42 4,479.49 4,622.06 4,964.34 5,099.41 5,232.29 5,633.95 5,761.22 5,887.01 28 1.18 1.57 1.99 9.14 12.62 16.45 30.30 37.47 44.69 30 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 31 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 32 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 33 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 34 857.46 897.61 936.60 1,039.33 1,090.93 1,141.58 1,268.39 1,319.80 1,370.47 35 3,254.53 3,400.20 3,545.21 3,860.26 4,031.05 4,199.11 4,534.43 4,693.24 4,850.22 36 714.13 740.20 766.03 803.47 833.21 862.68 913.38 947.59 981.20 37 1,052.45 1,316.80 1,598.15 1,929.98 2,145.52 2,314.36 2,608.28 2,772.24 2,920.88 38 2,259.66 2,351.30 2,435.74 2,572.99 2,651.43 2,730.37 2,893.92 2,976.82 3,060.11 39 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 40 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 41 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 6.76 

42 - 52 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Total 45,355.38 47,495.21 49,587.68 53,653.74 56,101.04 58,517.24 63,280.09 65,611.04 68,072.23 
2001 Lake Mead Sedimentation Survey 

16

Table 3 (continued) - 10 Foot Contour Areas in Acres 

Sheet No 

1060 1070 1080 1090 

Elevation 1100 1110 

1120 1130 1140 

1,2,3 85.50 119.99 156.03 210.66 258.78 326.58 410.59 486.26 559.45 

4 4,119.37 4,290.42 4,472.16 4,922.14 5,079.86 5,238.01 5,748.25 5,953.32 6,163.19 5 5,514.01 5,629.15 5,746.86 5,917.08 6,021.01 6,125.75 6,306.17 6,414.52 6,524.90 

6,7 7,567.41 7,691.31 7,811.89 8,086.20 8,218.47 8,347.21 8,609.85 8,727.27 8,843.22 

8 3,372.31 3,418.46 3,463.43 3,556.43 3,609.69 3,662.45 3,755.22 3,803.46 3,850.84 9 2,341.74 2,399.73 2,457.17 2,554.70 2,616.86 2,678.15 2,767.57 2,818.51 2,868.57 

10 0.27 1.06 2.23 3.67 5.33 7.44 10.00 12.18 14.41 

11,12 3,964.66 4,042.70 4,121.08 4,323.39 4,400.04 4,478.02 4,672.48 4,744.84 4,819.61 

14 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 15 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16 0.00 0.00 0.00 9.14 17.16 49.94 137.06 177.15 224.79 17 0.00 0.00 0.00 8.89 14.77 25.80 101.34 126.76 155.03 18 2,532.78 2,583.88 2,632.44 2,779.30 2,841.86 2,903.14 3,052.61 3,111.98 3,169.74 19 10,811.42 11,010.85 11,207.20 11,666.91 11,888.30 12,107.02 12,667.73 12,879.87 13,092.30 

20,21 436.11 490.25 548.43 678.47 726.00 786.71 914.95 972.11 1,037.76 

22 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 23 66.88 541.29 893.44 1,178.72 1,496.98 2,060.26 2,528.33 2,833.91 3,195.28 24 5,422.17 5,827.31 6,180.96 6,798.94 7,030.48 7,252.72 7,983.51 8,184.04 8,387.00 25 3,869.37 4,036.32 4,204.78 4,740.93 4,909.35 5,074.11 5,548.86 5,711.86 5,875.95 26 4,761.13 4,873.95 4,986.69 5,298.78 5,408.44 5,517.22 5,807.04 5,913.61 6,019.66 27 6,335.89 6,478.38 6,620.70 7,030.99 7,179.50 7,322.57 7,659.94 7,792.97 7,924.10 28 74.95 87.47 100.83 148.57 173.72 199.96 264.08 290.26 317.68 30 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 31 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 32 0.00 0.00 0.00 0.00 2.32 20.97 132.17 191.03 255.85 33 0.00 0.00 0.00 0.00 0.00 0.00 95.87 138.45 186.57 34 1,544.61 1,607.68 1,671.13 1,865.81 1,941.04 2,012.23 2,174.27 2,238.25 2,300.36 35 5,333.78 5,491.41 5,650.31 6,019.50 6,188.76 6,353.13 6,700.75 6,858.74 7,013.75 36 1,062.21 1,098.81 1,135.26 1,196.11 1,237.70 1,279.27 1,344.21 1,386.80 1,429.13 37 3,276.91 3,383.77 3,484.52 3,748.21 3,862.32 3,974.41 4,240.06 4,357.67 4,474.57 38 3,350.01 3,442.09 3,533.00 3,761.97 3,866.93 3,970.72 4,181.75 4,271.97 4,360.78 39 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 40 0.00 0.00 8.12 57.93 95.45 209.21 471.25 606.10 1,331.89 41 92.04 136.92 177.64 202.01 208.41 212.71 217.42 221.57 225.77 

42 - 52 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Total 75,935.53 78,683.20 81,266.33 86,765.46 89,299.52 92,195.69 98,503.33 101,225.46 104,622.16 
17

Table 3 (continued) - 10 Foot Contour Areas in Acres 

Sheet No 

1160 1170 1180 

Elevation  1190 1200 1210 1220 1230 

1,2,3 770.02 838.77 915.76 1,134.64 1,228.53 1,328.48 1,593.17 1,681.21 

4 6,931.98 7,177.18 7,424.59 7,964.22 8,133.08 8,302.79 8,671.16 8,812.95 5 6,842.32 6,980.97 7,123.50 7,338.47 7,504.22 7,682.08 7,906.27 8,060.99 

6,7 9,227.99 9,336.29 9,446.90 9,700.68 9,834.83 9,962.86 10,212.63 10,392.97 

8 3,991.80 4,038.07 4,083.54 4,179.17 4,230.04 4,279.00 4,330.22 4,380.27 9 2,981.04 3,029.98 3,078.57 3,177.91 3,258.52 3,337.77 3,469.12 3,592.40 

10 19.54 21.40 23.17 32.49 38.43 44.50 52.54 60.93 

11,12 5,067.79 5,135.03 5,200.87 5,375.87 5,466.15 5,557.82 5,755.81 5,871.92 

14 0.00 0.00 0.00 0.00 0.00 0.00 97.93 347.09 15 0.00 0.00 0.00 0.00 0.00 0.00 13.18 31.98 16 406.39 456.31 513.11 706.22 771.27 841.73 1,016.89 1,078.14 17 314.69 371.05 439.99 685.36 767.90 851.13 1,064.77 1,132.64 18 3,348.48 3,401.45 3,452.10 3,560.68 3,624.33 3,686.58 3,807.81 3,868.09 19 13,955.00 14,165.75 14,374.02 14,966.37 15,185.24 15,384.46 15,881.89 16,058.96 

20,21 1,332.72 1,420.85 1,530.83 1,850.95 1,961.56 2,081.57 2,573.93 2,752.73 

22 32.80 52.80 345.14 979.61 1,238.06 1,550.75 2,554.41 2,977.29 23 4,449.33 5,028.05 5,788.23 6,463.32 6,746.92 7,055.01 7,737.18 7,990.32 24 9,228.69 9,434.59 9,638.42 10,252.55 10,469.90 10,674.78 11,061.20 11,247.32 25 6,468.51 6,623.86 6,776.79 7,247.17 7,457.08 7,661.64 8,052.56 8,206.43 26 6,408.99 6,509.23 6,609.40 6,875.23 7,001.21 7,127.88 7,363.49 7,463.02 27 8,465.95 8,615.22 8,761.67 9,241.49 9,442.85 9,638.63 10,161.05 10,359.86 28 410.14 440.28 470.35 540.59 580.55 621.15 733.18 790.99 30 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 31 1.57 7.32 67.82 129.75 151.09 177.41 520.00 636.78 32 463.78 596.68 735.59 881.24 958.24 1036.51 1252.03 1333.02 33 348.77 413.16 482.46 634.28 696.61 761.03 870.24 934.12 34 2,499.97 2,555.86 2,610.00 2,767.95 2,832.78 2,896.07 3,009.99 3,058.87 35 7,442.80 7,583.96 7,723.81 7,946.01 8,079.76 8,212.87 8,437.06 8,574.67 36 1,530.88 1,577.12 1,624.08 1,739.16 1,828.67 1,921.25 2,080.58 2,179.67 37 4,818.72 4,921.67 5,024.64 5,263.92 5,406.26 5,547.31 5,760.05 5,874.31 38 4,604.28 4,682.89 4,758.31 4,928.37 5,038.97 5,149.46 5,301.42 5,387.63 39 0.00 0.00 0.00 24.16 33.81 44.28 59.55 75.72 40 3,078.92 3,383.60 3,541.52 3,798.83 3,936.74 4,068.31 4,270.46 4,385.49 41 239.14 245.14 251.16 263.28 274.18 285.35 342.86 360.94 

42 - 52 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Total 115,683.0 119,044.5 122,816.3 130,650.0 134,177.8 137,770.4 146,014.6 149,959.7 
2001 Lake Mead Sedimentation Survey 

18

Elevation Boulder and Virgin Basins Temple Bar/ Virgin Canyon Gregg Basin Grand Bay Pierce Basin Lower Granite Gorge Overton Arm 

1935 2001 1935 2001 1935 2001 1935 2001 1935 2001 1935 2001 1935 2

660 1,000 0 0 0 0 0 0 670 7,000 0 0 0 0 0 0 680 21,000 0 0 0 0 0 0 690 43,000 0 0 0 0 0 0 700 73,000 1 0 0 0 0 0 

710 111,000 26 0 0 0 0 0 720 156,000 202 0 0 0 0 0 730 207,000 5,199 0 0 0 0 0 740 265,000 28,417 0 0 0 0 0 750 336,000 67,440 0 0 0 0 0 760 422,000 121,482 1,000 0 0 0 0 0 770 518,000 185,741 3,000 0 0 0 0 0 780 626,000 260,074 7,000 0 0 0 0 0 790 745,000 349,344 15,000 0 0 0 0 0 800 877,000 465,444 27,000 0 1,000 0 0 0 0 810 1,026,000 609,651 41,000 0 2,000 0 0 0 0 820 1,189,000 772,023 57,000 311 3,000 0 0 0 0 830 1,365,000 948,535 76,000 3,383 7,000 0 0 0 0 840 1,553,000 1,137,661 95,000 11,856 15,000 0 0 0 0 850 1,755,000 1,338,350 116,000 26,439 28,000 0 0 0 0 860 1,970,000 1,553,308 139,000 46,118 46,000 3 1,000 0 0 0 870 2,197,000 1,780,139 164,000 70,271 68,000 14 2,000 0 0 0 880 2,437,000 2,016,372 191,000 97,383 92,000 312 5,000 0 0 0 890 2,690,000 2,266,939 220,000 126,993 120,000 1,468 9,000 0 0 0 900 2,955,000 2,532,757 251,000 159,127 150,000 5,661 15,000 0 1,000 0 0 1,000 910 3,234,000 2,809,297 285,000 193,250 182,000 15,381 21,000 0 3,000 0 1,000 0 3,000 920 3,529,000 3,098,525 321,000 229,529 215,000 29,891 29,000 0 6,000 0 4,000 0 6,000 930 3,837,000 3,408,734 360,000 268,951 251,000 48,994 38,000 0 11,000 0 7,000 0 11,000 940 4,161,000 3,729,848 401,000 310,657 291,000 72,132 47,000 0 16,000 0 11,000 0 16,000 950 4,498,000 4,060,698 445,000 354,469 332,000 99,441 57,000 0 22,000 0 16,000 0 25,000 960 4,851,000 4,411,053 491,000 401,683 375,000 130,911 67,000 0 29,000 0 22,000 0 38,000 970 5,218,000 4,773,929 540,000 451,295 419,000 165,932 79,000 0 36,000 0 29,000 0 55,000 980 5,598,000 5,146,619 591,000 502,870 467,000 204,436 91,000 0 44,000 0 37,000 0 76,000 990 5,994,000 5,539,157 647,000 558,125 516,000 247,432 104,000 0 52,000 0 48,000 0 104,000 

1000 6,405,000 5,949,161 705,000 616,882 567,000 294,171 118,000 0 61,000 0 59,000 0 139,000 1010 6,832,000 6,371,475 766,000 678,198 621,000 343,577 132,000 0 71,000 0 73,000 0 182,000 1020 7,275,000 6,810,939 830,000 742,827 678,000 396,076 148,000 0 81,000 0 87,000 0 233,000 1030 7,735,000 7,272,098 899,000 811,669 736,000 452,414 166,000 0 91,000 0 103,000 0 292,000 1040 8,212,000 7,746,866 969,000 883,214 797,000 511,422 184,000 0 103,000 0 120,000 0 361,000 1050 8,704,000 8,234,073 1,043,000 957,244 861,000 572,816 204,000 0 117,000 0 138,000 0 439,000 1060 9,214,000 8,745,095 1,121,000 1,035,952 928,000 638,896 224,000 0 131,000 0 159,000 0 528,000 1070 9,739,000 9,271,537 1,202,000 1,117,814 998,000 707,989 247,000 0 146,000 0 181,000 0 631,000 1080 10,281,000 9,806,529 1,288,000 1,201,761 1,069,000 779,053 271,000 0 163,000 0 204,000 0 746,000 1090 10,841,000 10,366,905 1,377,000 1,291,333 1,144,000 855,132 296,000 0 181,000 0 228,000 0 874,000 1100 11,418,000 10,943,941 1,470,000 1,384,839 1,222,000 934,789 323,000 0 200,000 0 255,000 0 1,012,000 1110 12,013,000 11,531,586 1,567,000 1,480,933 1,303,000 1,017,119 352,000 6 222,000 0 282,000 0 1,160,000 1120 12,625,000 12,143,336 1,669,000 1,581,944 1,387,000 1,104,654 383,000 346 244,000 0 311,000 0 1,320,000 1130 13,256,000 12,772,751 1,775,000 1,686,792 1,474,000 1,196,037 415,000 1,223 268,000 0 342,000 0 1,492,000 1140 13,904,000 13,416,975 1,885,000 1,794,681 1,564,000 1,290,126 450,000 5,179 293,000 0 375,000 0 1,675,000 1150 14,569,000 14,077,141 1,999,000 1,905,641 1,656,000 1,386,788 488,000 15,307 319,000 0 410,000 0 1,874,000 1160 15,254,000 14,766,195 2,116,000 2,021,194 1,752,000 1,487,286 527,000 32,248 349,000 0 447,000 0 2,089,000 1170 15,959,000 15,468,756 2,239,000 2,139,245 1,851,000 1,589,795 570,000 58,962 378,000 0 486,000 0 2,320,000 1180 16,685,000 16,182,627 2,365,000 2,259,375 1,951,000 1,693,943 613,000 91,313 411,000 0 526,000 0 2,570,000 1190 17,432,000 16,930,140 2,495,000 2,384,444 2,055,000 1,802,251 660,000 131,473 445,000 0 569,000 0 2,840,000 1200 18,197,000 17,695,217 2,630,000 2,512,678 2,161,000 1,913,578 708,000 174,034 481,000 0 614,000 0 3,129,000 1210 18,984,000 18,475,718 2,769,000 2,643,844 2,270,000 2,027,725 758,000 218,686 519,000 0 661,000 0 3,442,000 1220 19,797,000 19,283,171 2,912,000 2,779,228 2,381,000 2,145,561 812,000 265,371 558,000 0 710,000 0 3,775,000 1230 20,632,000 20,111,593 3,059,000 2,917,917 2,495,000 2,266,010 867,000 313,681 600,000 0 760,000 0 4,134,000 

* Original capacity from 1963-64 study. ** GIS computed capacity execpt for Grand Bay, Peirce, and Lower Granite Gorge Basins. Used 1963-64 data for listed bas