Keyhole Reservoir

2003 Sedimentation Survey

U.S. Department of the Interior

Bureau of Reclamation

Technical Service Center

Denver, Colorado July 2005
REPORT DOCUMENTATION PAGE Form Approved

0MB No. 0704-0188

1. AGENCY USE ONLY (Leave Blank) 1 2. REPORT DATE 3. REPORT TYPE AND DATES COVERED

1 July 2005 Final ______________________________

4. TITLE AND SUBTITLE 5. FUNDING NUMBERS

Keyhole Reservoir PR

2003 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

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSORING/MONITORING

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

Denver CO 80225-0007 DIBR

11. SUPPLEMENTARY NOTES

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

12a. DISTRIBUTION/AVAILABILITY STATEMENT 12b. DISTRIBUTION CODE

13. ABSTRACT (Maximum 200 words)

The Bureau of Reclamation surveyed Keyhole Reservoir in May 2003 to develop new reservoir topography

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

conducted between reservoir elevation 4,091.7 (feet) and 4,091.8 (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 by digitizing the developed reservoir contour

lines from the U.S. Geological Survey quadrangle (USGS quad) maps of the reservoir area. This study

assumed no change, since the 1979 range line survey, from elevation 4,090 and above.

As of May 2003, at spillway crest elevation 4,099.3, the surface area was 9,411 acres with a total capacity

of 188,671 acre-feet. Since dam closure on February 12, 1952, about 12,495 acre-feet of change have been

estimated below elevation 4,099.3, resulting in a 6.2 percent loss in reservoir volume.

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

______________________

16. PRICE CODE

17. SECURITY 18. SECURITY 19. SECURITY CLASSIFICATION 20. LIMITATION OF

CLASSIFICATION CLASSIFICATION ABSTRACT

OF REPORT OF ABSTRACT

OF THIS PAGE

UL UL UL

UL

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

Prescnbed by ANSI StcL 239-18

298-102
Keyhole Reservoir

2003 Survey

Prepared by

Ronald L. Ferrari

U.S. Department of the Interior

Bureau of Reclamation

Technical Service Center

Water Resources Services

Sedimentation and River Hydraulics Group

Denver, Colorado July 2005
ACKNOWLEDGMENTS

The Reclamations Sedimentation and River Hydraulics Group of the

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

Ronald Ferrari and Sharon Nuanes of the TSC and John Strachan of the

Great Plains Region 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.

11
CONTENTS

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Page

Introduction i

Summary and Conclusions 2

Reservoir Operations 3

Hydrographic Survey Equipment and Method 3

Keyhole Reservoir Datum 5

Reservoir Area and Capacity 5

Topography Development 5

Development of 2003 Surface Areas 6

2003 Storage Capacity 6

Reservoir Sediment Analyses 7

References 8

TABLES

Table

I Reservoir sediment data summary (page 1 of 2) 9

1 Reservoir sediment data summary (page 2 of 2) 10

2 Summary of 2003 survey results 11

FIGURES

Figure

I Keyhole Reservoir location map 1

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

3 Keyhole Reservoir topographic map 1 13

4 Keyhole Reservoir topographic map 2 15

5 Keyhole Reservoir topographic map 3 17

6 Keyhole Reservoir topographic map 4 19

7 2003 area and capacity curves 21

111
INTRODUCTION 

Keyhole Dam and Reservoir, about 11 miles east of Moorcroft and 21 miles southwest of 

Sundance, is located in Crook County on the Belle Fourche River of northeast Wyoming 

(figure 1). The dam, reservoir, and facilities are part of the Keyhole Unit that provides storage 

for irrigation, municipal, and industrial water supplies, flood control, fish and wildlife 

conservation, recreation, and sediment control for the Pick-Sloan Missouri Basin Project. 

Buffalo B i 

Grassy L ak 

Jackson Lake 

Weeks CabinWyoming 

Figure 1 - Keyhole Reservoir Location Map. 

The reservoir, formed by a zoned rolled earth embankment structure, was completed in 1952. 

The dam's dimensions are: 

Hydraulic height1 

Top width 

Crest elevation 

feet 

feet 

feet2 

Structural height 

Crest length 

168 feet 

3,420 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 the National Geodetic Vertical Datum of 1929 (NGVD29) and 2.1 feet lower than the North American Vertical 

Datum of 1988 (NAVD88). 
The spiliway is an open concrete channel that extends through the dike on the right abutment.

The spillway consists of a concrete inlet structure, an uncontrolled concrete crest, and an open

concrete-lined chute having a small flip bucket at the downstream end. The ogee crest is at

elevation 4,099.3 and has a length of 19.25 feet. The discharge capacity is 10,850 cubic feet per

second (cfs) at maximum reservoir elevation 4,128.7.

An outlet works is located near the left abutment and consists of a concrete intake tower, an

upstream outlet tunnel, a gate chamber containing four 3.5 foot square high-pressure slide gates,

a downstream horseshoe-shaped outlet tunnel, and an open concrete chute and stilling basin. The

discharge capacity is 1,480 cfs at maximum reservoir elevation 4,128.7.

The drainage area above Keyhole Dam is approximately 1,953 square miles and all is considered

sediment contributing. The reservoir length, at elevation 4,090, is about 13 miles (including all

the contributing bays) with an average width of 0.75 miles.

SUMMARY AND CONCLUSIONS

This Reclamation report presents the 2003 results of the survey of Keyhole Reservoir. The

primary objective of the survey was to gather data to:

develop reservoir topography

compute area-capacity relationships

estimate storage depletion due to sediment deposition

A real-time kinematic (RTK) global positioning system (GPS) control survey established a

temporary horizontal and vertical control point near the reservoir for the hydrographic survey.

The GPS base was set over the National Geodetic Survey (NGS) datum point "J 120" that was

located several miles from the study area. The horizontal control was in the Wyoming state

plane east 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 the National Geodetic Vertical Datum of 1929 (NGVD29) and 2.1 feet lower than NAVD88.

The underwater survey was conducted in May 2003 between reservoir elevation 4,091.7 and

4,091.8. The bathymetric survey used sonic depth recording equipment interfaced with RTK

GPS for determining sounding locations within the reservoir. The system continuously recorded

depth and horizontal coordinates of the survey boat as it navigated along grid lines covering

Keyhole Reservoir. The positioning system provided information to allow the boat operator to

maintain a course along these grid lines. Water surface elevations recorded by the Reclamation's

reservoir gauge during the time of collection were used to convert the sonic depth measurements

to reservoir bottom elevations. The 2003 above-water area of Keyhole Reservoir was

determined by digitizing previously developed contour lines from the USGS quad maps of the

reservoir area. The 2003 survey assumed no change, since the 1978 survey, from elevation

4,090 and above.

2
The 2003 Keyhole Reservoir topographic map is a combination of the USGS quad contours and

the underwater survey data. A computer graphics program using the collected reservoir data

generated the 2003 reservoir surface areas at predetermined contour intervals. The 2003 area

and capacity tables were produced by a computer program that used measured contour surface

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

increments (Bureau of Reclamation, 1985).

Tables 1 and 2 contain summaries of the Keyhole Reservoir and watershed characteristics for the

2003 survey. The 2003 survey determined that the reservoir has a total storage capacity of

188,671 acre-feet and a surface area of 9,411 acres at spiliway crest elevation 4,099.3. Since

closure in February of 1952, the reservoir has an estimated volume change of 12,495 acre-feet

below reservoir elevation 4,099.3. This volume represents a 6.2 percent loss in total original

capacity at this elevation.

RESERVOIR OPERATIONS

Keyhole Reservoir is part of the Pick-Sloan Missouri Basin Project that provides storage for

irrigation, municipal and industrial water supplies, flood control, fish and wildlife conservation,

recreation, and sediment control. The May 2003 capacity table shows 623,321 acre-feet of total

storage below the maximum water surface elevation 4,128.7. The 2003 survey measured a

minimum lake bottom elevation of 4,024.9. The following values are from the May 2003

capacity table:

• 294,187 acre-feet of surcharge between elevation 4,111.5 and 4,128.7.

• 140,463 acre-feet of flood control between elevation 4,099.3 and 4,111.5.

• 182,079 acre-feet ofjoint use between elevation 4,051.0 and 4,099.3.

• 6,305 acre-foot of inactive storage between elevation 4,036.0 and 4,051.0.

• 287 acre-foot of dead storage below 4,036.0.

Keyhole Reservoir inflow and end-of-month stage records are listed by water year on table 1 for

operation period 1952 through 2003. The inflow values are computed by the Bureau of

Reclamation's Great Plains regional office and for some years show negative inflow. The

average computed inflow, for water years 1952 through 2003, was 16,918 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 4,100.4 in 1978 and minimum

elevation 4,046.4 in 1955.

HYDROGRAPHIC SURVEY EQUIPMENT AN]) METHOD

The hydrographic survey equipment was mounted in the cabin of a 24-foot trilìull 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 sofiware for collecting the underwater data. An on-board generator

3
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 

outputs fiom an 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 output is 

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

Wyoming's NAD83 state plane east zone coordinate system. The RTK GPS system employs 

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

Keyhole Reservoir hydrographic survey was conducted in May of 2003 between reservoir 

elevation 4,091.7 and 4,091.8 (Reclamation project datum). The bathymetric survey was 

conducted using sonic depth recording equipment, interfaced with an 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 along 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. The underwater data 

set includes about 130,700 data points. 
The 2003 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 computer recorded bottom

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

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

elevations.

Keyhole Reservoir Datum

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

survey from the NGS control point "J 120" to tie horizontal and vertical control to a temporary

point used for this study and the reservoir water surface. All vertical information for this study is

referenced to the Reclamation reservoir water surface gauge measurements that were found to be

near the NGVD29 and 2.1 feet lower than NAVD88. The horizontal control was in the

Wyoming state plane east coordinate zone in NAD83.

RESERVOIR AREA AND CAPACITY

Topography Development

The topography of Keyhole Reservoir was developed from the 2003 collected underwater data

and the digitized contours from the USGS quad maps. The digitized USGS contour lines of

Keyhole Reservoir were elevations 4,086 and 4,100 along with a partial contour labeled 4,090.

ARC/INFO geographic information system (GIS) software was used to transform the digital

aerial contours to Wyoming's NAD 1983 state plane coordinates, east zone. The digitized

contour elevation 4,086 was used to performed a hardclip around the 2003 underwater data of

Keyhole 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 data available to represent the upper elevations of the 2003

surveyed reservoir bottom. Using ARCEDIT, the 2003 underwater data and the 4,086 contour

were plotted. The plot found that some of the 2003 bottom data plotted slightly outside of this

contour. Using select and move commands within ARCEDIT, the vertices of the clip were

shifted to contain the 2003 underwater data. This clip was assigned an elevation of 4,086.5 to

reflect the upper elevation bottom data collected in 2003.

Contours for the reservoir below elevation 4,086.5 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.

S
The TIN software uses a method known as Delaunay's 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 Keyhole 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 Keyhole

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

4,025.0 through elevation 4,080.0. Due to no above water data collection, the 2003 study

assumed no change in area, since the 1978 survey, for elevation 4,090.0 and above. Also due to

limited data near elevation 4,085, this final contour and resulting surface area was interpolated as

explained below. The 2003 contour topography is presented on figures 3 through 6.

Development of 2003 Surface Areas

The 2003 TIN generated surface areas for Keyhole Reservoir were computed at 1-foot

increments from elevation 4,025.0 to 4,085.0. The 2003 underwater survey measured a

minimum reservoir bottom elevation of 4,024.9. 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 2003 survey areas at 2-foot and 5-foot increments from elevation

4,025.0 through 4,080.0 were used to compute the new area and capacity tables. This study

assumed no change in surface area, since the 1978 survey, from elevation 4,090.0.0 and above.

As noted previously, the surface area at elevation 4,080 was interpolated using the limited 2003

data in this range and the digitized USGS contours. Using ARC/INFO edit tools, the 4,085

contour was adjusted in the upper end of each reach, within some of the reservoir coves, and

along some of the shores using the USGS quad contours and 2003 bathymetry as a guide. There

was enough data for computer development of this contour, but it was decided that there was

insufficient data along some of the reservoir bays and upstream reaches to reflect the actual

location of this contour. It was determined that the resulting surface area from the computer

generated 4,085 contour indicated a much greater loss than actually occurred. With no above

water collection, the only means to develop this contour was to interpolate its location.

2003 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 2003 surveyed

surface areas at 2- and 5-foot contour intervals from reservoir elevation 4,025.0 to elevation

6
4,080.0 were used as the control parameters for computing the 2003 Keyhole Reservoir capacity.

Since this study did not collect above water data, the interpolated survey area of elevation 4,085

and the 1978 surface areas at 5-foot increments for elevation 4,090.0 and above were used to

complete the area and capacity table development. 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 0.00000 1 for Keyhole 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. By differentiating the capacity

equations, which are of second order polynomial form, the final area equations are derived:

y = a1 + a7x + a3x2

where: y=capacity

x = elevation above a reference base

a1 = rntercept

a2 and a3 = coefficients

Results of the Keyhole Reservoir area and capacity computations are listed in table 1 and

columns 8 and 9 of table 2. On table 2, columns 2 and 3 list the original area and capacity

values. Columns 4 and 5 list the 1978 surface areas and capacity values. A separate set of 2003

area and capacity tables has been 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 original, 1978, and 2003 area-capacity

curves are plotted on figure 7. As of May 2003, at spillway crest elevation 4,099.3, the surface

area was 9,411 acres with a total capacity of 188,671 acre-feet.

RESERVOIR SEDIMENT ANALYSES

Figure 7 is a plot of Keyhole Reservoir surface area and capacity for the original, 1978, and 2003

computed values. The plots illustrate the differences between the surveys. Since Keyhole Dam

closure in February of 1952, the measured total volume change at reservoir elevation 4,099.3

was estimated to be 12,495 acre-feet. The estimated average annual rate of capacity lost for this

period (51.3 years) was 243.6 acre-feet per year. The storage loss in terms of percent of original

storage capacity was 6.2 percent at spiliway crest elevation 4,099.3. From table 1 and 2, the

2003 study shows that of the total computed sediment 7.5 percent, or 940 acre-feet, has

accumulated below dead storage elevation 4,036.0 with the rest accumulating in the active

storage areas of the reservoir.

It must be noted that the 2003 area and capacity tables were generated assuming no change since

the 1978 surveyed area and capacity from elevation 4,090.0 and above which in all probability is

not the case. The 1978 survey measured about 12 percent of the total measured sediment above

7
elevation 4,090 with the majority of this depositing between elevation 4,090 and 4,095. The

reservoir has operated above elevation 4,090 during many years of its operation. The 1978

survey reflected the first 26.3 years of operation when the majority of the upper reservoir

sediment deltas are usually formed. Since 1978, it is assumed additional sediments have

deposited in the upper reservoir elevation, but more than likely not to the extent of what was

measured in 1978. The usual case is for the upper reservoir delta to begin to extend further

downstream and deposit in lower elevations of the reservoir. The 2003 underwater survey

measured the deposition below elevation 4,085, but an above water survey would be needed to

accurately measure the deposition above this elevation.

The original 74 years of estimated sediment accumulation for Keyhole Reservoir was 63,900

acre-feet below elevation 4,099.3 of which 55,900 acre-feet was projected to deposit above

elevation 4,051.0. The original estimated annual inflow would have been 863.5 acre-feet per

year. The 2003 study calculated an annual inflow of sediment of 243.6 acre-feet per year that

would extrapolate to a total sediment accumulation of 18,026 acre-feet in the first 74 years of

operation. The 1978 survey measured an annual inflow of 281.9 acre-feet per year. Both

surveys results only calculated about thirty percent of the original estimate. Further analysis

would be necessary to determine why the original estimate is so much greater than what the two

surveys have reflected.

REFERENCES

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

New York.

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, May 2003. Denver Office, Keyhole Reservoir Area and Capacity

Tables, Pick-Sloan Missouri Basin Project, Great Plains Region, Billings, MT.

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

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

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

Environmental Systems Research Institute, Inc. (ESRI), 1992. ARC Command Refrrences.
RESERVOIR SEDIMENT

DATA SUNMARY Keyhole Reservoir

NAME OF RESERVOIR 1

DATA SHEET NO.

D 1. OWNER Bureau of Reclamation 2. STREAM Belle Fourche River 3. STATE Wyoming

A 4. SEC. 27 TNT . 51 N RANGE 56 N S. NEAREST P.O. Moorcroft 6. COUNTY Crook

N 7. LAT 44 22 55" LONG 104° 45' 45° 8. TOP OF DAN ELEVATION 4,134.0 9. SPILLWAY CRES'" EL 4,099.3w

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

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

S BEGAN

E a. SURCHARGE 4,128.7 20,721 294,195 635,920

R

V

b. FLOOD CONTROL 4,111.5 15,273 140,559 341,725

2/12/52

o

C POWER

d. JOINT USE _______________ _______________ 16. DATE

R e. CONSERVATION 4,099.3 9,417

______________

191,453 201,166 NORMAL

f. INACTIVE 4,051.0 920 8,486 9,713 OPERATION

g. DEAD 4,036.0 239 1,227 1,227 10/25/52

- 17. LENGTH OF RESERVO:R 13 MILES AVG . WIDTH OF RESERVOIR 0.75 MILES

B 18. TOTAL DRAINAGE AREA 1,953 SQUARE MILES 22. MEAN ANNUAL PRECIPITATION 15.5 INCHES

A 19. NET SEDIMENT CONTRIBUTING AREA 1,953' SQUARE MILES 23. MEAN ANNUAL RUNOFF 0.i66 INCHES

I

20. LENGTH MILES AV. WIDTH 24. MEAN ANNUAL RUNOFF 16,918 ACRE-FEET

21. MAX. ELEVATION MI N . ELEVATION 25. AINOJAL TEMP. MEAN 45°F RANGE -38°F to 110°F5

5 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

_________________________________

E 2/52 26.3 26.3 Contour D 5-5: 9,4170 201,16G 11.9

Y 1978 Range (U) 30 9,411 193,753 11.4

5/03 25.0 S1.3 Contour D) 2-51 9,411 188,671 11.2

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

A SURVEY ANNUAL __________________________________________

T PRECIP. a. MEAN ANN. b. MAX. ANN. C. TOTAL

_______________

a. MEAN ANN.

_____________

b. TOTAL

A

1978 20,028 100,316 526,736 20,028 526,736

5/03 13,560° 52,t32 339,000 16,918 865,736

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

SURVEY

a. TOTAL J

b. AU. ANN. C. /MI.-YR. a. TOTAL b. AV. ANNUAL J

c. /MI.-YR.

1978 7,413 281.9 0.144 7,413 281.9 0.144

5/03 5,08210 203.3 0.104 12,495 243.6 0.125

26. DATE OF 39. AV. DRY 40. SED. DEP. TONS/WI.-YR. 41. STORAGE LOSS, PCT. 42.

SURVEY NT. (#/FT") ________________

a. PERIOD J

________________

b. TOTAL TO

______________

a. AV.

__

J

__________________

b. TOTAL TO

______

a.

_______

b.

1978 0.14 3.7

5/03 0.1210

26.

DATE

43. DEPTH DESIGNATION RANGE BY RESERVOIR ELEVATION

OF

SURVE

4016-

4040

4040-

4051

4051-

4060

4060-

4070

4070-

4080

4080-

4090

4090-

crest

PERCENT OF TOTAL SEDIMENT LOCATED WITHIN DEPTH DESIGNATION

5/03 12.2 12.8 20.4 18.5 13.7 16.1 6.3

26.

DATE

44. REACH DESIGNATION PERCENT OF TOTAL ORIGINAL LENGTH OF RESERVOIR

OF

SURVE

0-10 10-

20

20-

30

30-

40

40-

50

50-

60

60-

70

70-

80

80-

90

90-

100

100-

105

105-

110

110-

115

115-

120

120-

125

Y PERCENT OF TOTAL SEDIMENT LOCATED WITHIN REACH DESIGNATION

Table 1. - Reservoir sediment data summary (page 1 of 2)
45. RANGE IN RESERVOIR OPERATION9 ___________ ___________

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

1952 4,056.0 2,702 1953 4,059.4 4,048.7 20,486

1984 4,052.8 4,049.0 1,258 1955 4,067.5 4,046.4 47,579

:956 4,062.4 4,054.2 9,631 1957 4,057.0 4,052.5 14,240

1958 4,055.7 4,050.3 8,944 1959 4,057.9 4,049.9 12,335

1960 4,062.0 4,051.0 13,498 1961 4,055.6 4,049.4 (-) 732

1962 4,079.7 4,049.1 98,349 1963 4,085.0 4,078.6 17,385

1964 4,091.8 4,081.2 47,364 1965 4,092.8 4,089.2 14,094

1966 4,092.0 4,088.8 (-) 7,981 1967 4,092.9 4,088.5 12,520

1968 4,090.8 4,088.9 149 1969 4,091.8 4,088.4 12,194

1970 4,092.0 4,088.8 6,057 1971 4,096.3 4,088.5 43,693

1972 4,098.8 4,093.8 48,406 1973 4,096.4 4,094.3 (-) 5,295

1974 4,095.7 4,091.9 2,945 1975 4,094.5 4,091.4 (-) 7,014

1976 4,093.7 4,091.1 9,346 1977 4,092.5 4,087.9 4,149

1978 4,100.4 4,087.6 :00,318 1979 4,096.1 4,093.1 2,702

1980 4,093.3 4,086.6 )-) 8,908 1981 4,086.6 4,071.9 )-) 846

1982 4,078.2 4,071.5 24,018 1983 4,079.7 4,074.4 7,769

1984 4,084.8 4,074.6 33,345 1985 4,083.0 4,076.3 )-) 4,093

1986 4,081.3 4,076.0 17,535 1987 4,085.1 4,078.5 26,024

1988 4,083.3 4,075.5 (- 756 1989 4,077.9 4,070.7 5,927

1990 4,075.5 4,067.3 9,407 1991 4,074.0 4,066.7 14,198

1992 4,066.9 4,060.6 2,043 1993 4,080.4 4,060.3 52,832

1994 4,087.6 4,079.5 31,415 1995 4,088.6 4,083.6 20,539

1996 4,094.7 4,087.5 36,163 1997 4,098.6 4,093.0 41,316

1998 4,098.3 4,095.9 8,793 1999 4,099.1 4,097.2 29,851

2000 4,097.4 4,095.4 (-) 13,507 2001 4,097.0 4,095.1 1,818

g14 7777 (7t7 3 4150 4 17

46. ELEVATION - AREA CAPACITY DATA FOR 2003 CAPACITY1'

ELEVATION AREA CAPACITY ELEVATION AREA CAPACITY ELEVATION AREA CAPACITY

4,024.9 0 0 4,025 0.2 0 4,026 1.5 0

4,028 2.5 4 4,030 10.2 17 4,032 18.5 45

4,034 54.2 118 4,035 84.0 187 4,036 115.2 287

4,038 172.0 574 4,040 259.4 1,005 4,042 344.2 1,609

4,044 438.2 2,391 4,045 485.7 2,853 4,046 539.1 3,366

4,048 631.2 4,535 4,050 703.7 5,871 4,051 737.7 6,592

4,052 773.7 7,348 4,054 849.0 8,971 4,055 899.5 9,845

4,056 975.0 10,783 4,058 1,141.0 12,900 4,060 1,344.0 15,385

4,062 1,529.4 18,258 4,064 1,740.2 21,528 4,065 1,825.8 23,311

4,066 1,920.1 25,184 4,068 2,114.9 29,219 4,070 2,363.2 33,697

4,072 2,692.5 38,753 4,074 3,008.8 44,454 4,075 3,174.1 47,546

4,076 3,327.7 50,795 4,078 3,650.6 57,775 4,080 3,958.0 65,383

4,085 4,949.0 87,651 4,090 6,267 115,691 4,095 '7,974 151,293

4,099.3 9,411 188,671 4,100 9,645 195,341 4,105 11,329 247,776

4,110 13,150 308,973 4,111.5 13,730 329,134 4,115 15,085 379,561

4,120

4129

16,965

70.855

459,686

679.858

4,125 19,055 549,736 4,128.7

___________

20,721 623,321

47. REMARKS AND REFERENCES

____________

Uncont rolled spillway . All elevations in feet. Based on original project datum reported as NGVD29.

2 Original values compu ted from 5-foot contours.

Total of main stream, 8.3 miles and two smaller arms that make up the reservoir at elevation 4,090.

From USGS water year records.

Bureau of Reclamation Project Data Book, 1981.

Calcul ated using mean annual computed inflow value of 16,918 AF, item 24, 1952 through 2003.

Annual computed inflows by Reclamation GP Regiona Office . Water years from 1952 t hrough 2003.

Surface area & capaci ty at elevation 4,099.3, top of active conservation, ay indicated year. The capacities

were computed by BOR program ACAP.

Maximum and minimum elevations and annual computed inflows by water year from 1952 through 2003

)Recl amation computed values and records)

10 All sediment computa tions are computed by comparing the 1978 and 2003 survey resul ts with the original

resul ts at spillway crest elevation 4,099.3. This assumed the original data is of a reliable accuracy.

The 2 003 survey assumed no change since the 1978 survey from elevation 4,090 and above. Computed storage

loss is due to accuracy differences between original and 2003 surveys and due to accumulation of sediment.

Capacities computed by Reclamation's ACRE computer program.

48. AGENCY MAKING SURVEY Bureau of Reclamation

49. AGENCY SUPPLYING DATA Bureau of Reclamation DATE December 2004

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

10
-a

-a

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

1978 1978 2003 2003 Sediment

Elev. Original Original 1978 1978 Sediment Computed 2003 2003 Sediment Computed Volume

Survey Capacity Survey Survey Volume Sediment Survey Survey Volume Sediment 1978 03

Acres F Aç AC-Ft Acres Ac Ft Ac - Ft

4,128.7, 20,721 635,920 20,721 628,403 7,517 100.0 20,721 623,321

4125.01 19,056 562,333 19,055 554,817 7,516 100.0 19,055 549,736

4,120.0 l6,96S 472,280 16,965 464,767 7,513 99.94 16,965 459,6861

4,115.0 15,085

392'155L 15,085 384,642 7,513 99.9 15,085 379,561

4,111.5 13,7321 341,725 13,730 334,215' 7,510 99.9 13,730 329,134

4,110.0 13,152 321,563 13,1501 314,055 7,508 99.9 13,150 308,973

4,105.0 11,347' 260,315' 11,329 252,857 7,458 99.21 11,329 247,776

4,100.0 9,644 207,838 9,6451 200,422 7,416 98.7 9,645 195,341

4,099.3 9,417 201,166 9,411 193,753 7,413 98.6 9,411 188,671 12,495 100.0 5

4,095.0 8,023 163,6701 7,974' 156,375 7,295 97.0 7,974 151,2931 12,377 99.1 5

4,090.0, 6,486 127,3984 6,267 120,772 6,626 88.1 6,267 115,69]' 11,707 93.7 5

4,085.0 5170 98,258 5062l 92,450 5,808 77.3 4949.0 87,651 10,607 84.9'

4,080.0, 4,103 75,075 3,982 69,840 5,235 69.6 3958.01 65,383 9,692 77.6' 4

4,075.0' 3,359 56,420 3,227 51,817 4,603 61.2 3174.1 47,546 8,8741 71.0 4

4,070.0 2,536 41,683 2,406, 37,735 3,948 52.5 2363.2 33,697 7,986 63.9 4

4,065.0 2,035 30,255 1,953 26,837 3,418 45.5 1825.8 23,311 6,944 55.6 3

4,060.0 1,643 21,060 1,552' 18,075 2,985 39.7 1344.0 l5,385i 5,675 45.4 2

4,055.0 1,200 13,953 1,025 11,632 2,321 30.9 899.5 9,845 4,108 32.9

4,051.0 920 9,713 8154 7,952 1,761 23.44 739.0 6,592 3,121 25.0 1

4,050.0 850 8,8281 763' 7,1624

,

1,666 22.2 703.7 5,871 2,957 23.7 1

4,045.0 626, 5,138 536' 3,915 1,223 16.3 485.7 2,853 2,285' 18.3 1

4,040.0 415 2,535 331 1,747' 788' 10.5 259.4 1,0051 1,530' 12.2

4,036.0 1 239 1,227 180 726 5011 6.71 115.2 287 940 7.5 ,

4,030.0, 75 335' 41 107 228' 3.0 10.2 17 318 2.5

4,024.91 251 83 1 2

811 1.1 0.0 0

,

83, 0.7

4,020.0 5 101 0, 0 10 0.1 0.01 0 10 0.1

4,0l6.0 0 0 0, 0 0 0.0 0.0 0 0 0.0

1 Elevation of reservoir water surface.

2 Original reservoir surface areas.

3 Original reservoir capacity computed using ACAP.

4,1978 measured reservoir surface area. , 4

,

I 511978 reservoir capacity computed using ACAP .

61978 computed sediment volume, column (3) column (5)

71Measured s ediment in percentage of total sediment, 7,517 acre feet, by elevation.

8 2003 measu red reservoir surface area. Areas for elevation 4,090 and above from 1978 survey.

912003 reservoir capacity computed using ACAP .

I 1012003 measured sediment volume column (3) - column (9) .

11 Measured s ediment in percentage of total sediment, 12,495 acre-feet, by elevation.

' I

12 Measured s ediment volume from 1978 to 2003, column (5) column (9)

13 Measured s ediment in percentage my elevation from 1 978 to 2003. Total sediment volume of 5,08 2 acre feet

14 Depth of reservoir expressed in percentage of total depth (112.7), from maximum water surface.

13 14

percent Percent

Sediment Reservoir

1978-03 Depth

,082

,082

081

'799

,457

271

038

526

,690

,,787

360

- ,29l

,0621

742

439

90

2

0

0

100,0

100.0

100.0

94 .4

87.7

84 .0

79.5

69.4

52.9

35.2

26.8

25.4

20.9

14 .6

8.6

1.8

0.0

0.0

0.0

100.0

96 .7

92 .3

87.8

84 .7

83.4

79.0

74 .5

73.9

70.1

65.7

61.2

56.8

52.4

47.9

43.5

39.0

34.6

31.1

30.2

25.7

21.3

17.7

12 .4

7.9

3.5

0.0

H

C/D

0

0

I
*

/

t /

/

ou r c e

/

-- / /

t (

(

/

-

Ke y h 0 1 e 0 a m

Location

A

- -

\ / \

-

-

'\

C

H Euntat dat urn S sea ue Wy m g

St te P]see Co Ed t by tern

-

\, /____

Ed t Z C (54053)

I

\ \

Vert1Ca datum based on OE]5fl4)

/ P S \ S pno)ect datum based on Natorna(

I Geodetic Verntca1 OSturn ot tg2d (NSVD2Y)

I =

______

1)2paz21r

-II /

i / \ \ Z44$'81------------------ [1C1M//41 APP

1

1FD8Y

__________________ _____________ ________ ___________ ___________ _____ ____________________- ______-_______

, Co/oicdo D[CO/.

_____

13

Figure 3. - Keyhole Reservoir topographic map, No 1.
5.

.5

Location

N

w

8 /2i S;l1

S,Sn IiYdi

Horizontal datum based on Wyomings

State Plane Coordinate System.

Eust Zone. (NAD83)

VertiCdl datum b8Sed on OrigIns)

pro)ect datum based on Nation5]

Geodetat Vertizal Datum of 1950 (NOVD2Y)

15

/2°nveI, Co/oitoii PlC 01 21001

Figure 4. - Keyhole Reservoir topographic map, No. 2.
/

/

3

///

t/

/

t

3

/

I

rigure J.-Is.
ii

'S

OOOOe±

'S

'S

'S

5'

'S

'S

5'

'S

/

/

/

/

I

/

I

"S

5'

t 'Se

-

5'. a

"

5' 5 -'".. -

-

- .- -

I

Location

N

S

a e

G: /.&W

Horizontal datum based on WyCm19 S

State Plane Coordinate System.

East Zone. INADOSI

Ventical datum based nit onigind]

project datum based on Natoflmt

Geodetic Vbrtital Datum of 1929 (NGVD2Y)

Danys,', Co/orado DEC O/ 2'D91

19

Figure 6. - Keyhole Reservoir topographic map, No. 4.
21,000

4,130.0 -

---------

4,110.0

4,090.0

4-

w

I

4,070.0

4,050.0

4,030.0

4,010.0

0

Area-Capacity Curves for Keyhole Reservoir

18,900 16,800 14,700 12,600 10,500 8,400 6,300 4,200 2,100

I

Capacity Area

_ _

L

2003 Survey

1978 Survey

Original Survey

65000 130000 195000 260000 325000 390000 455000 520000 585000

Capacity (acre-feet)

Figure 7. - 2003 area and capacity curves.

0

4,130.0

4,110.0

4,090.0

4,070.0

4,050.0

4,030.0

- 4,010.0

650000