Lahontan Reservoir

2004 Survey

U.S. Department of the Interior

Bureau of Reclamation

Technical Service Center

Denver, Colorado March 2005
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Lahontan Reservoir PR

2004 Survey

6. AUTHOR(S)

Ronald L. Ferrari ________________________

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION

Bureau of Reclamation, Technical Service Center, Denver CO 80225-0007 REPORT NUMBER

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Bureau of Reclamation, Denver Federal Center, P0 Box 25007, AGENCY REPORT NUMBER

Denver CO 80225-0007

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11. SUPPLEMENTARY NOTES

Hard copy available at Bureau of Reclamation Technical Service Center, Denver, Colorado

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13. ABSTRACT (Maximum 200 words)

The Bureau of Reclamation surveyed Lahontan Reservoir in June 2004 to develop new reservoir

topography and compute a present storage-elevation relationship (area-capacity tables). The underwater

survey, conducted between reservoir elevation 4,153.2 (feet) and 4,156.0 (project datum), used sonic depth

recording equipment interfaced with a real-time kinematic (RTK) global positioning system (GPS) that

gave continuous sounding positions throughout the underwater portion of the reservoir covered by the

survey vessel. The above-water topography was obtained from aerial photography flown on November 4

of 1988. This study assumed no change since the 1988 aerial survey from elevation 4,155 and above.

As of June 2004, at spillway crest elevation 4,162.0, the surface area was 13,159 acres with a total capacity

of 289,721 acre-feet. At maximum reservoir elevation 4,169.0, the surface area was 17,764 acres with a

total capacity of 400,734 acre-feet.

14. SUBJECT TERMS 15. NUMBER OF PAGES

reservoir area and capacity! sedimentation! reservoir surveys/ sonar! sediment distribution!

contour area! reservoir area! sedimentation survey! global positioning system! lake

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NSN 7540-01-280-5500 Standard Form 298 (Rev. 2-89)

Prescribed by ANSI Std, 239-18

298-102
Lahontan Reservoir

2004 Survey

Prepared by

Ronald L. Ferrari

- I

U.S. Department of the Interior

Bureau of Reclamation

Technical Service Center

Water Resources Services

Sedimentation and River Hydraulics Group

Denver, Colorado March 2005
ACKNOWLEDGMENTS

The Reclamation's Sedimentation and River Hydraulics Group of the

Technical Service Center (TSC) prepared and published this report.

James Lively of the Lahontan Basin Fallon Office (LBFO) was the team

leader for this study. Ronald Ferrari and Walter Johnson of the TSC and

Robert Sevey and James Lively of LBFO conducted the hydrographic

survey. Ron Ferrari of the TSC completed the data processing needed to

generate the new topographic map and area-capacity tables. Sharon

Nuanes of the TSC developed the final topographic map. Kent Collins

of the TSC performed the technical peer review of this documentation.

UNITED STATES DEPARTMENT OF THE

iNTERIOR

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.

BUREAU OF RECLAMATION

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.

The information contained in this report regarding commercial products

or firms may not be used for advertising or promotional purposes and is

not to be construed as an endorsement of any product or firm by

Reclamation. The information contained in this report was developed for

the Bureau of Reclamation; no warranty as to the accuracy, usefulness,

or completeness is expressed or implied.

H
CONTENTS

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Page

Introduction 1

Summary and Conclusions 2

Reservoir Operations 3

Hydrographic Survey Equipment and Method 4

Lahontari Reservoir Datum 5

Reservoir Area and Capacity 5

Topography Development 5

1988 contourdatum 6

Development of 2004 Contour Areas 8

2004 Storage Capacity 8

2004 Reservoir Analyses 9

References 10

Table

TABLES

1 Reservoir surface area comparisons 7

2 Reservoir sediment data summary (page 1 of 2) 11

2 Reservoir sediment data summary (page 2 of 2) 12

3 Summary of 2004 survey results 13

FIGURES

Figure

1 Lahontan Reservoir location map 1

2 Survey vessel with mounted hydrographic equipment on Jackson Lake in Wyoming 4

3 Lahontan Reservoir topographic map 1 15

4 Lahontan Reservoir topographic map2 17

5 Lahontan Reservoir topographic map 3 19

6 Lahontan Reservoir topographic map4 21

7 Lahontan Reservoir topographic map 5 23

8 Lahontan Reservoir topographic map 6 25

9 Lahontan Reservoir topographic map 7 27

10 Lahontan Reservoir topographic map 8 29

11 Lahontan Reservoir topographic map 9 31

12 Lahontan Reservoir topographic map 10 33

13 Lahontan Reservoir topographic map 11 35

14 Lahontan Reservoir topographic map 12 37

15 Lahontan Reservoir topographic map 13 39

16 Lahontan Reservoir topographic map 14 41

17 Lahontan Reservoir topographic map 15 43

18 Lahontan Reservoir topographic map 16 45

19 2004 area and capacity curves 47

111
INTRODUCTION 

Lahontan Dam and Reservoir, about 17 miles west of Fallon and 45 miles northeast of Carson 

City, Nevada, is located in Churchill County on the Carson River (fig. 1). The dam, reservoir, 

and facilities are part of the Newlands Project that supplies irrigation water to the TruckeeCarson Irrigation District. The reservoir captures water from the Carson River along with 

Truckee River diversions through the Truckee Canal. 

Davis- Y 

Figure 1 - Lahontan Reservoir Location Map. 

The reservoir, formed by a rolled earth and gravel zoned dam was completed in 191 5. The dam 

consists of two zones with earth and gravel on the upstream zone and gravel fill on the 

downstream zone. The dam dimensions are: 

Hydraulic height1 

Top width 

Crest elevation 

feet 

feet 

feet2 

Structural height 

Crest length 

162 feet 

1,325 feet 

1 The 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, or ASCE's 

Nomenclature for Hydraulics. 

2 Elevations in feet. All elevations based on the original project datum established by U.S. Bureau of Reclamation that was 

reported to be 3.75 feet higher than the National Geodetic Vertical Datum of 1929 (NGVD29) and 0.3 feet higher than the North 

American Vertical Datum of 1988 (NAVD8 8). 
There are two ungated fixed crest overflow spillways located on each abutment of the dam.

Each spillway is 250-foot-long with a crest elevation of 4,162.0. Twenty-inch-high wooden

flashboards are on top of each crest and are removable for projected spillway use. Modifications

in 1985 increased the combined discharge capacity of the spiliways to 30,000 cubic feet per

second (cfs) at dam crest elevation 4,174.0.

An outlet works is located through the left central section of the dam embankment and consists

of a gated 1 14-foot-high concrete intake tower that controls the flow to two 9-foot horseshoe

conduits. The lowest inlet gate is at elevation 4,070.0. The total discharge capacity of the

combined outlets is 2,000 cfs at reservoir elevation 4,162.0. There are two powerplants with a

maximum rated discharge capacity of 1,000 cfs.

The drainage area above Lahontan Dam is approximately 1,799 square miles and all is

considered sediment contributing. The reservoir, at elevation 4,162 is about 18 miles in length

with an average width of 0.9 miles.

SUMMARY AND CONCLUSIONS

This Reclamation report presents the 2004 results of the survey of Lahontan Reservoir. The

primary objective of the survey was to gather data to:

develop reservoir topography

compute area-capacity relationships

The hydrographic survey crew utilized horizontal and vertical control that was previously

established as part of the Lahontan Reservoir network. The global positioning system (GPS)

base was set over monument "Dam 2" that was located near the dam. The horizontal control was

in the Nevada state plane west coordinate zone in the North American Datum of 1983 (NAD83)

and the vertical control was tied to the National American Vertical Datum of 1988 (NAVD88).

All elevations in this report are in feet and referenced to the Reclamation project vertical datum

that is reported to be 3.75 feet higher than National Geodetic Vertical Datum of 1929 (NGVD29)

and 0.3 feet higher than NAVD88.

The underwater survey was conducted in June 2004 between reservoir elevation 4,154 and 4,156.

The bathymetric survey used sonic depth recording equipment interfaced with a real-time

kinematic (RTK) GPS capable of detennining sounding locations within the reservoir. The

system continuously recorded depth and horizontal coordinates of the survey boat as it navigated

along grid lines covering Lahontan Reservoir. The positioning system provided information to

allow the boat operator to maintain a course along these grid lines. The reservoir's water surface

elevations recorded by the USGS reservoir gauge during the time of collection were used to

convert the sonic depth measurements to reservoir bottom elevations.

The 2004 above-water area of Lahontan Reservoir was developed from aerial photography

obtained on November 4, 1988 near reservoir elevation 4,091.3. The 1988 survey developed 5-

foot reservoir contours from elevation 4,095 and above. The 1988 data was on the Lahontan

2
Dam local vertical datum that was (+) 3.75 feet above NGVD29 and the horizontal coordinates

were Nevada's state plane, west zone, on the North American Datum of 1927.

For this study, mapping tools were utilized to convert the digital aerial information to match the

2004 underwater data in Nevada's state plane coordinates, west zone, NAD83. With the 2004

underwater data as a background, the 1988 aerial contour 4,150 was adjusted in the upper end of

the reservoir to reflect changes that had occurred since 1988. This adjusted contour was assigned

elevation 4,150 and was used as a clip to enclose the 2004 underwater data during contour

development. The final 2004 Lahontan Reservoir topography is a combination of the 1988 aerial

contours from elevation 4,155 and above, the adjusted 4,150 aerial contour, and the 2004

underwater collected data. A computer graphics program generated the 2004 reservoir surface

areas at predetermined contour intervals from these combined data sets. The 2004 area and

capacity tables were generated by a computer program that used the measured contour surface

areas and a curve-fitting technique to compute area and capacity at prescribed elevation

increments (Bureau of Reclamation, 1985).

Tables 2 and 3 contain summaries of the Lahontan Reservoir and watershed characteristics for

the 2004 survey. The 2004 survey determined that the reservoir has a storage capacity of

289,721 acre-feet and a surface area of 13,159 acres at spillway crest elevation 4,162.0.

RESERVOIR OPERATIONS

Lahontan Reservoir is part of the Newlands Project that provides a water supply to the TruckeeCarson frrigation District. The June 2004 capacity table shows 400,734 acre-feet of total storage

below the maximum water surface elevation 4,169.0. The 2004 survey measured a minimum

lake bottom elevation of 4,073.6. The following values are from the June 2004 capacity table:

• 87,750 acre-feet of surcharge elevation 4,163.67 and 4,169.0.

• 23,263 acre-feet ofjoint use between elevation 4,162.0 and 4,163.67.

• 289,721 acre-foot of active storage between elevation 4,070.0 and 4,162.0.

• 0 acre-foot of dead storage below 4,070.0.

Lahontan Reservoir available inflow and end-of-month stage records are listed by water year on

table 2 for operation period 1965 through 2003. The inflow values are from the USGS gauging

station "Carson River near Fort Churchill, Nevada." This station is located upstream of the

reservoir and measured only 1,302 square miles of the total 1,799 square miles of drainage area

above the dam. The listed values do not reflect the diverted Truckee River inflows through the

Truckee Canal to the reservoir. These gauge records were the only information available during

preparation of this report. The average computed runoff at this gauge, for water years 1911

through 2003, was 271,700 acre-feet per year. The table also lists the maximum and minimum

reservoir elevations by water year. The extremes for the period of record were maximum

elevation 4,164.43 in 1942 and minimum elevation 4,070.0 in 1929 (Geological Survey, 2003).

3
HYDROGRAPHIC SURVEY EQUIPMENT AND METHOD 

The hydrographic survey equipment was mounted in the cabin of a 24-foot trihull aluminum 

vessel equipped with twin in-board motors (figure 2). The hydrographic system included a GPS 

receiver with a built-in radio, a depth sounder, a helmsman display for navigation, a computer, 

and hydrographic system software for collecting the underwater data. An on-board generator 

supplied power to all the equipment. The shore equipment included a second GPS receiver with 

an external radio. The GPS receiver and antenna were mounted on a survey tripod over a known 

datum point and a 12-volt battery provided the power for the shore unit. 

Figure 2 - Survey vessel with mounted hydrographic equipment on Jackson Lake in Wyoming 

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 in the order of 2 centimeters horizontally and 3 centimeters vertically. The output is 

on the GPS datum of WGS-84 that the hydrographic collection software converted into Nevada's 

NAD83 state plane west zone coordinate system. The RTK GPS system employs two receivers 

that track the same satellites simultaneously just like with differential GPS. 

Lahontan Reservoir hydrographic survey was conducted in June of 2004 between reservoir 

elevation 4,153.2 and 4,156.0 (Reclamation project datum). The bathyrnetric survey was run 

using sonic depth recording equipment, interfaced with a RTK GPS, capable of determining 

sounding locations within the reservoir. The survey system software continuously recorded 

reservoir depths and horizontal coordinates as the survey boat moved across closely spaced grid 

lines covering the reservoir area. Most of the transects (grid lines) were run somewhat 

perpendicular to the downstream alignment of the reservoir at around a 300-foot spacing. Data 

was also collected along the shore as the boat traversed between transects. The survey vessel's 
guidance system gave directions to the boat operator to assist in maintaining the course along

these predetermined lines. During each run, the depth and position data were recorded on the

notebook computer hard drive for subsequent processing. Additional shoreline and shallow

water data was obtained by mounting the collection equipment in a smaller shallow draft boat.

The underwater data set includes about 3,470,000 data points.

The 2004 underwater data were collected by a depth sounder that was calibrated by lowering a

weighted cable below the boat with beads marking known depths. The depth sounder was

calibrated by adjusting the speed of sound, which can vary with density, salinity, temperature,

turbidity, and other conditions. The collected data were digitally transmitted to the computer

collection system via a RS-232 port. The depth sounder also produced an analog hard-copy chart

of the measured depths. The analog charts were printed for all survey lines as the data were

collected and recorded by the computer. The charts were analyzed during post-processing, and

when the analog charted depths indicated a difference from the recorded computer bottom

depths, the computer data files were modified. The water surface elevations at the dam, recorded

by the USGS gauge, were used to convert the sonic depth measurements to true lake-bottom

elevations.

Lahontan Reservoir Datum

Prior to the reservoir underwater survey, the hydrographic survey crew conducted a RTK GPS

survey to confirm the horizontal and vertical control of existing datums. RTK GPS was also

used to establish a temporary point in the upper portion of the reservoir and monitor the reservoir

surface elevation. The base was set on the NGS control point "Dam 2" that was listed as a third

order horizontal control point by the NGS. The regional office provided updated coordinate

information for the points listed below with Dam 2 labeled as "Dam 2- A." All vertical

information for this study is referenced to the Lahontan Reservoir water surface gauge

measurements that were found to be 3.75 feet higher than NGVD29 and 0.3 feet higher than

NAVD88. The horizontal control was in the Nevada state plane west coordinate zone in

NAD83. Following are coordinates for points used during the 2004 reservoir survey:

Dam 2- A Aluminum Cap C/L Bnd2e + Dam

East 2,486,473.8491 2,488,140.46

North 14,840,611.35492 14,839,308.70

Elevation 4,224.91 (NAVD88) 4,173.35 (NA\TD88)

Elevation 4,221.46 (NGVD29) 4,169.90 (NGVD29)

RESERVOIR AREA AND CAPACITY

Topography Development

The topography of Lahontan Reservoir was developed from the 2004 collected underwater and

the 1988 aerial contours. The 1988 aerial contours included 5-foot increments from elevation

4,095 to elevation 4,170. ARC/INFO geographic information system (GIS) software was used to

transform the digital aerial contours to Nevada's NAD 1983 state plane coordinates, west zone.

5
The aerial contour of elevation 4,150 performed a hardclip around the 2004 underwater data of

Lahontan Reservoir. This hardclip was used during the triangular irregular network (TIN)

development so interpolation did not occur outside the enclosed polygon. This contour was

selected since it was the closest available data to represent the upper elevations of the 2004

surveyed reservoir bottom elevations. Using ARCEDIT, the 2004 underwater data and the 1988

aerial contour at elevation 4,150 were plotted. The plot illustrated that in the upper end of the

reservoir the 2004 underwater data near elevation 4,150 was located downstream of the 4,150

aerial contour. This 2004 measured change since the 1988 survey was assumed to be due to

sediment deposition. For the 2004 analysis, the 1988 aerial developed 4,150 contour was

adjusted in the upper end of the reservoir to reflect the 2004 measured changes. Using select and

move commands within ARCEDIT, the vertices of the clip were shifted to fit the upper contour

around the 2004 underwater data at elevation 4,150. This clip was assigned an elevation of

4,150.0 to reflect the 2004 surface area.

Contours for the reservoir below elevation 4,150.0 were computed from the underwater data set

using the triangular irregular network (TIN) surface-modeling package within ARC/INFO. A

TIN is a set of adjacent non-overlapping triangles computed from irregularly spaced points with

x,y coordinates and z values. TIN was designed to deal with continuous data such as elevations.

The TIN software uses a method known as Delaunayzs criteria for triangulation where triangles

are formed among all data points within the polygon clip. The method requires that a circle

drawn through the three nodes of a triangle will contain no other point, meaning that sample

points are connected to their nearest neighbors to form triangles using all collected data. This

method preserves all collected survey points. Elevation contours are then interpolated along the

triangle elements. The TIN method is discussed in detail in the ARC/INFO V7.0.2 Users

Documentation, (ESRI, 1992).

The linear interpolation option of the ARC/INFO TINCONTOUR command was used to

interpolate contours from the Lahontan Reservoir TIN. In addition, the contours were

generalized by filtering out vertices along the contours. This generalization process improved

the presentability of the resulting contours by removing very small variations in the contour

lines. This generalization had no bearing on the computation of surface areas and volumes for

Lahontan Reservoir since the areas were calculated from the developed TIN. The areas of the

enclosed contour polygons at one-foot increments were developed from the survey data for

elevations 4,074.0 through elevation 4,150.0. The 2004 study assumed no change in area, since

the 1988 survey, for elevation 4,155.0 and above. The 2004 contour topography is presented on

figures 3 through 18.

1988 Contour Data

The 1988 contours of Lahontan Reservoir were developed by Reclamation's Mid-Pacific Region

from aerial photography obtained on November 4 of 1988. The reservoir level was very low

during the 1988 collection allowing an updated area and capacity table to be developed from

reservoir elevation 4091.3 to elevation 4,174.0 (dated 03/09/89). For the 2004 analysis, the 1988

digital contours were obtained from the regional office. These reservoir contours were at 5-foot

increments from elevation 4,095.0 and above. The 1988 aerial data was processed on Lahontan

6
Dam local vertical datum that is (+) 3.75 feet above the NGVD29. The coordinates were on the

Nevada State Plane, west zone, on the 1927 North American Datum.

As part of the 2004 analysis, the 1988 digital aerial contours were processed using the

ARC/INFO editing tools. This included converting the positioning data to Nevada State Plane,

west zone, in NAD83 and computing the surface area of the different contours. Obtaining the

surface areas required minor editing to close the contour polygons. This mainly occurred at

breaks in the contour lines where the mapping labels indicated the contour elevations. This was

completed for contour elevations 4095 through 4160. There was not enough digital information

to complete this process for contours 4165 and 4170.

The following table compares the surface areas in acres by reservoir elevation for the different

methods of development. The 1988 values are from the published Lahontan area and capacity

tables dated March 9, 1989. The 1988 GIS surface areas are from the 2004 ARC/INFO analysis

of the 1988 developed contours. As described previously, the 1988 digital contours required

minor editing to develop closed polygons for the 2004 study. The fourth colunm lists the surface

area differences between the methods of colunm 2 and 3. The fifth column lists the percent of

change between the two methods. The sixth column list the surface areas used to compute the

2004 area and capacity for Lahontan Reservoir. These 2004 surface areas, for elevations 4,095

through 4,145, were computed from the 2004 underwater collected data. Surface areas for

elevation 4,155 and above are from the 1988 survey area table, column 2, that assumed no

change since 1988. The surface area at elevation 4,150 is the adjusted surface area of the GIS

generated 1988 aerial contour as described above. The last column shows the percent of

difference between the 2004 surface area values and the 1988 table surface area values. The

table shows that the differences between the 1988 and 2004 survey results were not significant.

1988 1988 1988 1988 2004

Table GIS GIS - GIS - 2004 Areas -

Surface Surface Table Table Surface 1988 Table

Elev. Areas Areas Difference Percent Areas Percent

(feet) (acres) (acres) (acres) Diff. (acres) Diff

4095 838.4 872.0 33.6 4.0 809.0 3.5

4100 1,094.8 1,101.5 6.7 0.6 1,042.1 4.8

4105 1,337.0 1,341.8 4.8 3.6 1,265.3 5.4

4110 1,584.2 1,571.7 (-) 12.5 0.8 1,498.3 5.4

4115 2,008.4 2,015.0 6.6 0.3 1,926.6 4.1

4120 2,458.8 2,531.2 72.4 2.9 2,376.8 3.3

4125 2,995.1 3,026.5 31.4 1.0 2,930.9 2.1

4130 3,825.4 3,827.2 1.8 0.0 3,736.3 2.3

4135 4,639.1 4,635.2 (-) 3.9 0.1 4,574.9 1.4

4140 5,287.9 5,263.0 (-) 24.9 0.5 5,136.9 2.8

4145 5,895.8 5,922.0 26.2 0.4 5,779.5 2.0

4150 7,203.7 7,138.5 (-) 65.2 0.9 6,955.9 3.4

4155 8,495.5 8,538.0 42.5 0.5 8,495.5 0.0

4160 11,313.8 11,694.9 { 381.1 3.4 11,313.8 0.0 I

Table 1 - Reservoir surface area comparisons.

7
Development of 2004 Contour Areas

The 2004 contour surface areas for Lahontan Reservoir were computed at 1 -foot increments

from elevation 4,074.0 to 4,150.0. The 2004 underwater survey measured a minimum reservoir

bottom elevation of 4,073.6. These calculations were performed using the ARC/INFO

VOLUME command. This command computes areas at user-specified elevations directly from

the TiN and takes into consideration all regions of equal elevation. For the purpose of this study,

the measured 2004 survey areas at 2-foot increments from elevation 4,074.0 through 4,150.0

were used to compute the new area and capacity tables. This study assumed no change in

surface area, since the 1988 aerial data, from elevation 4,155.0 and above. As noted previously

the surface area at elevation 4,150 was generated from the adjusted 1988 aerial developed

contour. Using ARC/INFO edit tools the 4,150 contour was adjusted in the upper end using the

2004 underwater elevations as a guide. The resulting surface area was 6,955.9 acres compared

to the 1988 GIS surface area of 7,138.5 acres (table 1, column 3).

2004 Storage Capacity

The storage-elevation relationships based on the measured surface areas were developed using

the area-capacity computer program ACAP (Bureau of Reclamation, 1985). The 2004 surveyed

surface areas at 2- and 5-foot contour intervals from reservoir elevation 4,074.0 to elevation

4,150.0 were used as the control parameters for computing the 2004 Lahontan Reservoir

capacity. Since this study did not collect above water data, the 1988 surface areas at 5-foot

increments for elevation 4,155.0 through 4170.0 and the surface area for elevation 4,174.0 were

used to complete the area and capacity table. The program can compute an area and capacity at

elevation increments 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 error limit was set at 0.000001

for Lahontan Reservoir. 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 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. Differentiating the capacity equations, which are of second order

polynomial form, derives final area equations:

y = a1 + a2x + a3x2

where: y capacity

x = elevation above a reference base

a1 = intercept

a2 and a3 = coefficients

Results of the Lahontan Reservoir area and capacity computations are listed in table 2 and

columns 8 and 9 of table 3. On table 3, columns 3 list the 1969 capacity values found on a table

that was revised February 1972. Columns 4 through 6 list the 1988 surface areas and capacity

values. Column 6 is the recomputed 1988 capacities using ACAP. Colunms 8 and 9 list the

2004 area and capacity values. A separate set of 2004 area and capacity tables has been

8
published for the 0.01, 0.1 and 1-foot elevation increments (Bureau of Reclamation 2003). A

description of the computations and coefficients output from the ACAP program is included with

these tables. The 1969, 1988, and 2004 area-capacity curves are plotted on figure 19. As of June

2004, at spiliway crest elevation 4,162.0, the surface area was 13,159 acres with a total capacity

of 289,721 acre-feet.

2004 RESERVOIR ANALYSES

Figure 19 is a plot of available Lahontan Reservoir surface area and capacity values for the years

1969, 1988, and 2004. The surface area and capacity plots illustrate the differences between all

the report values for these survey years. Since there were no reliable original surface area and

capacity values for Lahontan Reservoir there was no means of computing sediment deposition

since dam closure in June of 1915. Column 10 of table 3 shows the capacity difference between

the recomputed 1988 capacity and the 2004 capacity. At elevation 4,150.0, the computed

difference is 5,259 acre-feet between the two surveys. A portion of this difference is due to

sediment inflow, but it is assumed a portion of this computed loss is also due to the differences

between methods of collection and analysis by the studies. Due to these unknowns, a reliable

sediment deposition and projection cannot be computed by comparing the 2004 survey results

with previous surveys of 1969 and 1988. During the original planning of Lahontan Reservoir,

the estimated loss of total capacity of the reservoir over the first 100 years of operation was 5.3

percent. Even with all the unknowns the comparison of the three surveys, figure 19 does

illustrate that overall changes have been minimal. The original design of the reservoir had a

dead pool elevation of 4,070.0 with only 100 acre-feet of capacity. The 2004 survey measured a

minimal elevation of 4,073.6 with a 46 acre-feet of capacity at reservoir elevation 4,080.0. The

2004 study results show that all of the original dead pool capacity is filled with sediment

deposition, but the total amount of deposition at the dam for the first 89 years of operation, 1915

through 2004, is minimal. Due to all of these conditions, a future survey of Lahontan should not

be needed for many years unless major sediment inflow events are observed.

9
REFERENCES

American Society of Civil Engineers, 1962. Nomenclature for Hydraulics, ASCE Headquarters,

New York.

Bureau of Indian Affairs, September 2003. Molina Complex, Burn edArea Emergency

Stabilization andRehabilitation Plan, Interagency Burned Area Emergency Response Team,

Nambe Pueblo, New Mexico.

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 ofSmall Dams, U.S. Government Printing Office,

Denver CO.

Bureau of Reclamation, June 2004. Denver Office, Lahontan Reservoir Area and Capacity

Tables, Newlands Project, Mid Pacific Region, Sacramento, CA.

Corps of Engineers, January 2002. Engineer and Design - Hydrographic Surveying,

EM 1110-2-1003, Department of the Army, Washington DC,

(www.usace.army.millinetlusace-docs/eng-manuals/em 1110-2-1 003/toc.htm).

Environmental Systems Research Institute, Inc. (ESRI), 1992. ARC Command References.

Geological Survey, 2003. Water Resources Data Nevada Water Year 2003, Water-Data Report

NV-03-1, U.S. Geological Survey, Carson City, NV.

10
RESERVOIR SEDIMENT

DATA SUMMARY Lahontan Reservoir

MANE OF RESERVOIR

1

DATA SHEET NO.

D 1. OWNER Bureau of Reclamation 2. STREN4 Carson River 3. STATE Nevada

A 4. SEC. 33 TWP. 19 N RANGE 26 B 5. NEAREST P.O. Fallon 6. COUNTY Churchill

M 7. LAT 39 27 45n LONG 119° 04 00" 8. TOP OF DAN ELEVATION 4174.0° 9. SPILLWAY CREST EL 4162.02

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

E ALLOCATION TOP OF POOL SURFACE AREA, CAPACITY, STORAGE ACRE- STORAGE

S ACRES ACRE-FEET FEET BEGAN

E a. SURCHARGE 4,169.0 __________________

108,500 425,800

R

b. FLOOD CONTROL ________________ _________________ ________________ V

o

POWER _______________ _______________

6/1915

d. Joint 4,163.67 __________________

22,200 317,300 16. DATE

R a. CONSERVATION 4,162.0 ________________

295,000 295,100 NORMAL

f. INACTIVE OPERATION

g. DEAD 4,070.0 __________________

100 100

- 17. LENGTH OF RESERVOIR l8 MILES AVG. WIDTH OF RESERVOIR 0.9 MILES

B 18. TOTAL DRAINAGE AREA 1,799 SQUARE MILES 22. MEAN ANNUAL PRECIPITATION 4.26 INCHES

A 19. NET SEDIMENT CON'IRIBU'IING AREA l,799 SQUARE MILES 23. MEAN ANNUAL RUNOFF 39? INCHES

20. LENGTH MILES AV. WIDTH MILES 24. MEAN ANNUAL RUNOFF 271 700 ACRE-FEET

I

21. MAX. ELEVATION MIN. ELEVATION 25. ANNUAL TEMP. MEAN 54°F RANGE -17°F to 110°F

S 26. DATE OF 27. 28. 29. TYPE OF 30. NO. OF 31. SURFACE 32. CAPACITY 33. C/I

U SURVEY PER. ACCL SURVEY RANGES OR AREA, AC. ACRE- FEET RATIO

R _________________ _______________ _________________________________________________

V

_________________________________

1988 Contour CD) 5-ft 13,159" 296,893"

E

Y

6/04 Contour CD) 2-ft l3,159 289,721

26. DATE OF 34. PERIOD 35. PERIOD WATER INFLOW, ACRE FEET WATER INFLOW TO DATE, RE

A

SURVEY ANNUAL __________________________________________

T

PRECIP. a. MEAN ANN. b. MAX. ANN. c. TOTAL

_______________

a. MEAN ANN.

_____________

b. TOTAL

A

6/04 271,700

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

SURVEY _________________________________________________

a. TOTAL b. AV. ANN. J

C. /MI.-YR.

________________

a. TOTAL

___________________

b. AV. ANNUAL

_______________

c. /MI.2-YR.

10

6/04

26. DATE OF 39. AV. DRY 40. SEn. DEP. TONS/MI.2-YR. 41. STORAGE LOSS, PCI. 42.

SURVEY MT. (#/FT3) ____________________________

a. PERIOD b. TOTAL TO

______________

a. AV.

________________

b. TOTAL TO

______

a.

_______

b.

10 10

6 / 04

26. - 43. DEPTH DESIGNATION RANGE FEET BELOW, AND ABOVE, CREST ELEVATION

DATE

SURVEY

PERCENT OF TOTAL SEDIMENT LOCATED WITHIN DEPTH DESIGNATION

2004

26. 44. REACH DESIGNATION PERCENT OF TOTAL ORIGINAL LENGTH OF RESERVOIR

DATE 0-10 10- 20- 30- 40- 50- 60- 70- 80- 90- 100- 105- 110- 115- 120-

Survey 20 30 40 50 60 70 80 90 100 105 110 115 120 125

PERCENT OF TOTAL SEDIMENT LOCATED WITHIN REACH DESIGNATION

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

11
45. RANGE IN RESERVOIR OPERATION7

YEAR MAX. ELEV. MIN. ELEV. INFLOW, AF YEAR MAX. ELEV. MIN. ELEV. INFLOW, AF

_____________ ______________ ______________ ______________

1965 4164.0 4131.4 382,300

1966 4158.2 4124.2 171,040 1967 448,700

1968 4160.8 4133.4 162,500 1969

_____________

4163.5

_____________

4131.0 560,800

1970 4163.4 4144.9 322,400 1971 4163.7 4142.4 295,200

1972 4163.2 4141.1 187,700 1973 4162.4 4139.8 276,200

1974 4162.3 4139.1 354,100 1975 4163.4 4141.0 321,400

1976 4154.8 4127.1 80,600 1977 4151.3 4102.6 26,260

1978 4160.5 4104.8 257,600 1979 4163.0 4142.5 235,200

1980 4160.5 4139.7 431,700 1981 4157.0 4117.4 121,300

1982 4162.4 4116.4 551,700 1983 4163.0 4147.2 804,600

1984 4159.3 4139.9 482,900 1985 4160.4 4135.2 197,500

1986 4163.2 4133.9 537,500 1987 4161.5 4124.5 110,900

1988 4148.7 4094.0 43,230 1989 4154.0 4091.0 166,400

1990 4153.3 4109.1 71,520 1991 4137.1 4100.7 72,980

1992 4133.2 4089.4 52,130 1993 4157.8 4091.8 340,000

1994 4147.4 4090.7 382,230 1995 4163.5 4091.9 633,400

1996 4164.2 4148.0 467,800 1997 4163.9 4144.5 604,200

1998 4163.4 4144.3 449,800 1999 4163.6 4149.2 425,300

2000 4157.4 4134.4 110,100 2001 4154.1 4129.0 53,500

2002 4155.3 4125.6 64,900 2003 4157.6 4128.7 198,100

46. ELEVATION - AREA - CAPACITY DATA FOR 2004 CAPACXEY9

ELEVATION AREA CAPACITY ELEVATION AREA CAPACITY ELEVATION AREA CAPACITY

2004 SURvEY 4,073.6 0 0 4,075 0.1 0

4,078 3.5 4 4,080 48.4 46 4,082 128.5 223

4,084 197.0 548 4,085 256.8 775 4,086 360.4 1,084

4,088 498.0 1,942 4,090 602.9 3,043 4,092 693.5 4,339

4,094 771.8 5,805 4,095 809.0 6,595 4,096 851.6 7,425

4,098 944.9 9,222 4,100 1,042.1 11,209 4,102 1,127.2 13,378

4,104 1,219.5 15,725 4,105 1,265.3 16,967 4,106 1,314.6 18,257

4,108 1,404.7 20,976 4,110 1,498.3 23,879 4,112 1,630.1 27,008

4,114 1,818.3 30,456 4,115 1,926.6 32,329 4,116 1,996.5 34,290

4,118 2,166.1 38,453 4,120 2,376.8 42,996 4,122 2,611.2 47,984

4,124 2,849.9 53,445 4,125 2,930.9 56,335 4,126 3,019.0 59,310

4,128 3,376.6 65,706 4,130 3,736.3 72,819 4,132 4,132.6 80,688

4,134 4,422.9 89,243 4,135 4,547.9 93,728 4,136 4,679.1 98,342

4,138 4,914.0 107,935 4,140 5,136.9 117,986 4,142 5,379.2 128,502

4,144 5,657.6 139,539 4,145 5,779.5 145,257 4,150 6,955.9 177,096

4,155 8,495.5 215,724 4,160 11,313.8 265,248 4,162 13,159 289,721

4,163.67

4.170

14,700

18222.8

312,984

418727

4,165

4174

15,927.6

20041.0

333,351

498.255

4,169

_________

17,764

__________

400,734

47. REMARKS AND REFERENCES

All elevations are in feet based on the original project datum that is 3.75 feet higher then NGVD29 and 0.3

feet higher than NAVD88.

2

Uncontrol led spillway. Top of 20-inch flashboards are at elevation 4,1 63.67 feet.

Values from Reservoir Capacity Allocation table dated 11/83. No reliable original values.

Length at elevation 4, 162.

From USGS water year records, 2003.

6

Bureau of Reclamation Project Data Book, 1981. Values for Newlands Project.

Mean annual runoff of 271,700 PS, item 24, from 1911 through 2003 from USGS gage "Carson River near Fort

Churchill , Nevada." Drainage area of gage ia 1,302 square miles compared to reservoi r drainage of 1,799.

Value does not account for additional inflow from the Truckee Canal diversion flows. Maximum and

minium elevations from USGS annual report for listed water years. Values from available records.

Surface area & capacit y at elevation 4,162.0, spillway crest elevation. 1988 capacity recomputed by

Reclamation's ACAP computer program.

All capac ities computed by Reclamation's ACAP computer program. The 20 04 survey assumed no change from

elevation 4,155 and above since 1988 survey.

10 Due to no original capacity values there are no capacity loss computati ons.

48. AGENCY MAKING SURVEY Bureau of Reclamation

49. AGENCY SUPPLYING DATA Bureau of Reclamation DATE March 2005

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

12
1 2 3 4 5 6 7 8 9 10 11

Elev 1969 1988 1988 1988 1969-88 2004 2004 1988-04

Survey Turvey Survey Survey Change Survey Survey C ernt

Feet Ac-Ft Acres Ac-Ft Ac-Ft Ac-Ft Acres Ac-Ft Ac-Ft Depth -

4,174.0 20,041 502,203 501,133 20,041.0 495,255 5,878 100.0

4,170.0 18,223 425,432 424,605 18,222.8 _ 418,727 5,878 96.5

4,169.0 17,764 _ 407,459 _ 406,612 17,764.0 400,734 5,878 95.6

4,165.0 *15,928 339,894 339,230 15,927.6 333,351 5,879 92.1

4,163.67 317,280 14,728 319,861 318,862 -1,582 14,700.0 312,984 5,878 90.9

4,162.0__-295,149 13,159 25,542 295,599 13,159.0 289,7211 5,878 89.5

4,160.0

4,155.0

272,552

: _225,609

11,314

8,495 _

270,671

222,763

271,126 1,426 _

221,6034,006

11,313.8

8,495.5 _

265,248 _

215,724

5,878

5,879 _

87.7

83.3

4,150.0 187,155 _ 7,204 183,623 182,355 4,p2j 6,956.0 177,096 5,259 _78.9

4,145 153,440 5,896 150,814 149,606 3,834 5,779.8 145,257 _ 4,349 74.6

4,140.0 127,781 5,288 _ 122,795 3,661 _ 70.2

4,135.0 l03,5l9 _

97,991 96,829 _ 6,9_4,547.9 93,728 _ 3,101 65.8

4130.0 82,701 _ 3825] 76,647 _ 75,668 _ 7,033 _ 3,736.3 _ 72,819 2849 61.4

4,125.0

] _ 59,780 58,617 6,680 ,930.9 _ 56,335 _ 2,282 57.0

4,120.0 50,891 _ 2,459 46,148 _ 44,982 5,909 _ 2,376.8 _42,996 1,986 52.6

4,1l5.0

:_

39076: 2,008 _ 34,993 _ 33,814 5,262 _ 1,926.6 _ 32,329 5 48.2

4,110.0 29,463 1,584 26,118] 24,8 4,63q 1,498.3 _ 23,879 _ 954

_

43.9

4,l05 21,845 _

4,100.0

1,337 18,842 _

2,758

17,530 _ 4,315 _

11,450 4,232

1,265.3 _

1,042.1

16,967

11,209

563

241 _

_39.5

35.1

4,095.0 10,472 _ 838 _ 7,959]_6,617 _ 3,855 _809.0 _ 6,595 _ 22 _ 30.7

4,091.3 J__

0 27.5

4,090.0 6,212 0 0 6,212 602.9 3,043 26.3

3,080 _0 0 3,080 25 75 21.9

4,080.0]

4,075.0 368 0 0

1,172 _

368]

48.4 _

0.1

46 17.5

4,073.6 _ - _254 0 0 _ _ 254 _ 0.0 0 11.9

- 9 0 _ 0 _91 _0.0 _ 0

4,065.0

4,060.0

I_

17 _

0

0 _ 0] __0.0

0 0.0

0

0

4.4

0.0

1 Elevation of reservoir water surface.

2 l969 reservoir surface areas not located.

3 1969 reservoir capacity values from revised table Feb.1972 .

measured reservoir surface areas from table 03/09/89.

1988 reservoir capacity from table 03/09/89. 198 9 table as

____

sumed 5,159 AF

__ -

at elevation 4,091. 3. ______

6 1988 reservoir capacity recomputed using ACAP. Assumed 3,8 65 AF at

-

at elevation 4,091.3. Computed capacity from 2004 survey. -______

7 1969 and 1988 computed difference, colunm (3) - c olumn (6).

8 2004 measured reservoir surface area. Areas for elevation

____________

4,155 and above :

___

from 1989_survey_: _ _______________ _____

-

____

-*

9 2004 reservoir capacity computed using ACAP. ]

10 _ 1988 and 2004 computed volume difference, column

___

(3) - column (9) .

____

14 Dpth of reservoir expreassd in percentage of total depth ( 114). ______ _____

Table 3. - Summary of 2004 survey results

13
N

/1

Vertical datum based on Lahoston

Dam LocSl datum ariich is

375 feet above trio Ntiona1

Geodetic Datum of 1929.

Horizontal datum based on Nevadas

State PIOnO CoordinatC System, West

Zone NADB3

Contours for elevations 4100 and above

devOloped from t9$ aerIal photogr'apriy

at 5 foot rnteroals The appen end Of

contour 4100 adjusted for 2004 uridereater

data

is

Figure 3. - Lahontan Reservoir topographic map, No 1.
Figure 4. - Lahontan Reservoir tonoranhic man. No 2.
19

Fipure 5. - Lahontan Reservoir toi,oranhic man. No. 3.
N

...

w E

S

w

9-/ I mt'

A;

,/

/

Lzsoo;

S

n.aza000-f- tdSa2000-'j-- 14S42000*

0' lOfvy

7LW2R*WR

VeotIval datum based Sm LV000tVO

Dam Local datum 5lch 19

3.75 feet above the Natorfal

Geodetsc Datum of 1929.

forszontal datum based off Nevada's

State 51a09 Cddrdtrfate System. West

lore (N5083)

CoNtours for' elevatorr 4150 arvi abose //U4O'1/ 4PPOVAL.,

devolsOed onrIdeB aer'a1photogr'aphf 'fBgy ,4PPROv1D ,

corftOur' 4150 adtuoted for 2004 uNderwater

data

Clr!dO

5 - /V

.

S

aw0aoo i :' ' - raoaooo- aoo$

21

Figure 6. - Lahontan Reservoir topographic map, No.4.
N

1462000 w L

oaoooo-i

S

1.11/

0 047

5z,/. /4W

10000-; 1004

14822000--

820o00-;

/

16

1*18060'

46,6000* 4616000- 14815000-;

2

14816000-; 48,6000+

622000±

14820000*

14610000± 148,6000±

$6470020

56VrY4f /48747

LA/øvTca'ff2,qlt'IR

VertiCal datum 00600 01/ La000ton ,40101

Dam Local datum wont/i is

3 75 feet dbOvO the NOt i or/SI

Geodetic Datum 51 7S29

Horizontal datum 000000 cr1 Nevada's

State Plane COOrdI//Ote System, West

Zvne (00083)

Contours for- elevations 4150 0/rd above /[7W/

aOrialphOtO9f00phy O4'Ft[D BY 4I'JVFD

tcmtour- 4100 ad(rzsted fcc 2004 06000-wat6r

, ,,,,_

_______________ _________

51? /7. 7001 5

23

Figure 7. - Lahontan Reservoir topographic map, No. 5.
WE

J

/

1/

-.5 1

-.

VetC3I dt based Ltr

Dam Local datum wiuco is

375 feet above tie flatior'al

Geodetic Datum of /925. rc4UojoY Location l-lor'izorltai datum bseo or' Nieoadas

State 51005 COOrdinatE System West

Zor'e NAD83)

CoritocirO for eleoatror-is ap aso above /[(liW/(A/ APOM/_

developed frOm l9S8 aerial photography U/IcKLD 8Y__ 4PD

voetour 4150 adjusted for' 2004 urroereater

25

Figure 8. - Lahontan Reservoir topographic map, No. 6.
N

___ ___ I

)

-

\7 I

J ri / \ c // // I

Vertical datum based or Lahonton

Oam Local datum shIch Is

375 eet SbOve the National

Geodetic Datum of 1929

Horizontal datum based on Nevada

State Plane Coordinate System. West

Zone 19A083)

Contours for e]evStiono 4j50 arid above

developed from 198€ Venial photv9rapfry

at 5 foot intervals The upper end of

cOntour 4150 adlustea for 2004 urrdeniuater

data

Figure 9. - Lahontan Reservoir topographic map, No. 7.

27
Figure 10. - Lahontan Reservoir topographic map, No. 8.
\ /

-

.

w

N 148 14000f

E

12080!

J ii

(J-f

y

\

\\ :

>H4a8a0oo.t

\

148 10000*

SI'

-

\

14810±

14s12000±

Y

r4S800

___

(

______

r.58r

Lt7 if 4.M'

Vertncal datum based orr 8rrerrtorl

Dam Local datum WtrICfl 00 4fl1y3fj7/j

75 f8et above the Natroflal

0000etIc Datum of 1929

tforozcrrtal datum based or 58240mb

St8te PlaIce Coor-dorrte SyStem. Cest

ZoOm N4D83) 31

Coutours for elevatrorrs 4150 aIrd above 1I'8) _. /T#//cA/ AVA1___

developed from 1988 aeroal photo9r'aphy

- CCK[D67 at S foot lrrtervalo roe upper erld of -

COOtOUr' 4150 adlubted for' 2004 urrdmrsater

d4ta Lnye,. CoIoro6o 5rP/_j__

Figure 11. -Lahontan Reservoir topographic map, No. 9.
rr

S

oOO$-

/ iaeo4 ) /

N

S

S

reef

iSV V

ka/e. fSV

S

ta,o4Ooo;

no S

iiiOOOO±

/ L

1

Beatfl

UeO4000+

Vertical datum based On Lahontori

Dam Local datum apich io 3 75 feet abooe the NatIonal

Geodetic Datum of 1925.

tforloontal datum based on Nevadan

State Plane Co0rdinat System. West

Zone (N0093)

Contoups for elevations 415') and abOVe

developed from 199S aerial ohotodraphy

at 5 foot Internals The upper' end Of

contour 4150 adjusted for 2004 underwater

data

days

aiYZOSF

0/i

LMtWIaY RfS7it'/I

TI2PIXY

3

AWBY____ 1[cW/4L APV_

ClICkED BY APIWOV[D

Figure 12. - Lahontan

,,Colorqdo

Reservoir topographic map, No. 10.

l_
14012800+ l462000 14812000+ 4022000-4- 40128004

L

44610000±

••

404

w

N

I

S

eli

14010000-4- 14640000+ 14810000±

2/,_ I,ali

4808000± 1

2

14800000±

Sm,

Vertical datum based on LAhonton

hOrn Local datum Which 10

375 feet above the National

Geodetic Datum Of 1929

HoriZontOI datum based on Nevadas

State Plane Coordinate System. West

Zone (NAD83 -

Contoury for elevations 4450 and Obove

developed from iges aerial photography

at 5 foot Intervals The upper end OF

contour 4150 adlusted fOr 2004 uhdera8ter

data

9

*4600000-f

5

Figure 13. - Lahontan Reservoir topographic map, Nc
47

34002000+

w

N

0

E

7

S

r,.t

2 & f.

ke/c /'?

9

14000000+ 14000000+

oo

s_

I

p

Ual0000+

2

r ,o0000004,

14000000- i4000000- jl006000±

N

(

14004000+

9

14000000+

GeTay K20/H

Vertical datum based On Lanonton

DSm Local datum which s

375 f eet ab ove the Nationa l

Geodetic Datum di 1929

Horizontal datum based or Nevada's

State Plane Coordinate System, West

Zone INADO3)

Cortoutp for elevatoons 4190 drid above iW4V8t //7aV/tl/ AP1WOML__

developed from 198-8 aerial photography G/[at[D8Y

,

at 5 fOot intervals The upper end of -

Contour 0150 adlUsted for 2004 underwater

dat a

___________ ______

/,flVef,_C/orca, 5[fl!/, Z'0121

7 I

Figure 14. - Lahontan Reservoir topographic map, No. 1

14000O- 18000000
Figure 15. - Lahontan Reservoir topographic map, No. 13.
41

Fipure 1 6 - Jahontan Reservoir t000QraDhic mao. No. 14.
43

Figure 17. - Lahontan Reservoir topographic map, No. 15.
45

Figure 18. - Lahontan Reservoir topographic map, No. 16.
Area-Capacity Curves for Lahontan Reservoir

22000 19800 17600 15400 13200 11000 8800 6600 4400

4,170.0

4,160.0

4,150.0

4,140.0

'.4,13O.O

4,120.0

4,110.0

4,100.0 _________ _________

4,090.0

4,080.0

4,070.0

A flfl A _________ ___________ ___________ ___________ ___________ ___________ ___________ ___________

2200 0

_ _ _ -_ _

Capacity Area

I;

2004 Survey

1988 Survey

1969 Survey

-"Wv.',

0

4,160.0

4,140.0

4,120.0

4,100.0

4,080.0

- 4,060.0

50500 101000 151500 202000 252500 303000 353500 404000 454500 505000

Capacity (acre-feet)

Figure 19. - 2004 area and capacity curves.