Millerton Lake 

2004 Survey 

U.S. Department of the Interior 

Bureau of Reclamation 

Technical Service Center 

Denver, Colorado March 2007 
U.S. Department of the Interior 

Bureau of Reclamation 

Technical Service Center 

Water Resources Services 

Sedimentation and River Hydraulics Group 

Water Supply, Use, and Conservation Group 

Denver, Colorado March 2007 

Millerton Lake 

2004 Survey 

prepared by 

Ronald L. Ferrari 

Sharon Nuanes 

ACKNOWLEDGMENTS

The Bureau of Reclamation's (Reclamation) Sedimentation and River Hydraulics Group 

and the Water Supply, Use and Conservation Group of the Technical Service Center 

(TSC) prepared and published this report. Ronald Ferrari of TSC and Robert Keller of 

the Mid-Pacific Regional Office conducted the underwater data collection. Ron Ferrari 

and Sharon Nuanes of the TSC completed the data processing needed to generate the new 

topographic map and area-capacity tables. Sharon Nuanes developed the final 

topographic maps presented in this report. Kent Collins of the TSC performed the 

technical 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.

ii
iii

REPORT DOCUMENTATION PAGE Form Approved 

OMB No. 0704-0188

The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering 

and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, 

including suggestions for reducing the burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson 

Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to 

comply with a collection of information if it does not display a currently valid OMB control number. 

PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 

1. REPORT DATE (DD-MM-YYYY) 

March 2007 

2. REPORT TYPE 3. DATES COVERED (From – To) 

5a. CONTRACT NUMBER 

5b. GRANT NUMBER 

4. TITLE AND SUBTITLE 

Millerton Lake 

2004 Survey 

5c. PROGRAM ELEMENT NUMBER 

5d. PROJECT NUMBER 

5e. TASK NUMBER 

6. AUTHOR(S) 

Ronald L. Ferrari 

Sharon Nuanes 

5f. WORK UNIT NUMBER 

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

Bureau of Reclamation, Technical Service Center, Denver, CO 80225 

8. PERFORMING ORGANIZATION REPORT 

NUMBER 

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR'S ACRONYM(S) 

Bureau of Reclamation, Denver Federal Center, PO Box 25007 

Denver, CO 80225-0007 11. SPONSOR/MONITOR'S REPORT 

NUMBER(S) 

12. DISTRIBUTION/AVAILABILITY STATEMENT 

13. SUPPLEMENTARY NOTES 

14. ABSTRACT 

The Bureau of Reclamation surveyed Millerton Lake in July 2004 to develop new reservoir topography and 

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

between reservoir water surface elevation 528.7 (feet) and 536.2, 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 August 28, 2001, at water surface 

elevation 496.2. This study assumed no change since the 2001 aerial survey from elevation 496.2 and 

above. 

As of July 2004, at conservation elevation 578.0, the surface area was 4,810 acres with a total capacity of 

521,482 acre-feet. At maximum reservoir elevation 585.0, the surface area was 5,010 acres with a total 

capacity of 555,763 acre-feet. 

15. SUBJECT TERMS 

reservoir area and capacity/ sedimentation/ reservoir surveys/ global positioning system/ multibeam 

sounders/ contour area/ 

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 

Table of Contents 

Millerton Lake 2004 Survey ...............................................................................................1 

Introduction.........................................................................................................................1 

Summary and Conclusions .................................................................................................3 

Reservoir Operations ..........................................................................................................4

Hydrographic Survey Equipment and Method ...................................................................8 

Reservoir Area and Capacity ............................................................................................10 

Topography Development..........................................................................................10 

Development of the 2004 Contours..................................................................... 11

Development of the 2004 Surface Areas.............................................................. 11 

2004 Storage Capacity................................................................................................23 

2004 Reservoir Analyses ..................................................................................................23 

References.........................................................................................................................26

Index of Figures 

Figure 1 - Friant Dam location map, California..................................................................1 

Figure 2 - Friant Dam downstream face. ............................................................................2 

Figure 3 - Survey vessel with mounted instrumentation on Jackson Lake in Wyoming. ...8 

Figure 4 - Multibeam collection system. ............................................................................9 

Figure 5 - Millerton Lake topographic map 1...................................................................13 

Figure 6 - Millerton Lake topographic map 2...................................................................15 

Figure 7 - Millerton Lake topographic map 3...................................................................17 

Figure 8 - Millerton Lake topographic map 4...................................................................19 

Figure 9 - Millerton Lake topographic map 5...................................................................21 

Figure 10 - 2004 area and capacity curves........................................................................25 

Index of Tables 

Table 1 - Reservoir sediment data summary (1 of 2)..........................................................5

Table 1 - Reservoir sediment data summary (2 of 2)..........................................................6

Table 2 - Summary of 2004 survey results. ........................................................................7 

v

Millerton Lake 2004 Survey 

Introduction 

Friant Dam and Millerton Lake, on the San Joaquin River, are located in Fresno 

County about 25 miles northeast of Fresno, California (figure 1). The dam and 

reservoir are major features of the Friant Division of the Central Valley Project 

that also includes the Friant-Kern and Madera Canals. The dam and lake control 

San Joaquin River flows, providing flood control, recreation, and a conservation 

storage. Friant Dam provides diversion flows into the Madera and Friant-Kern 

Canals and downstream releases meet requirements above Mendota Pool, prevent 

salt water from destroying thousands of acres in the Sacramento-San Joaquin 

Delta, and deliver water to a million acres of agricultural land in Fresno, Kern, 

Madera, and Tulare Counties in the San Joaquin Valley. Millerton Lake storage 

began on February 21, 1944 and is approximately 15 miles long with an average 

width of 0.5 miles. The drainage area above the dam is around 1,638 square miles 

of which 526 square miles is considered sediment contributing. 

Figure 1 - Friant Dam location map, California. 

1
Completed in 1942, the dam (figure 2) is a concrete gravity structure with 

dimensions of: 

 Hydraulic height1

 293 feet Structural height 319 feet 

 Top width 20 feet Crest length 3,488 feet 

 Crest elevation2

 581.3 feet 

Figure 2 - Friant Dam downstream face. 

The spillway consists of an overflow section at the center of the dam controlled 

by three 18-by-100-ft drum gates. The elevation at the top of the gates is 578.0. 

The discharge capacity of the spillway is 83,000 cubic feet per second (cfs) at 

dam crest elevation 578.0. 

The outlet works to the San Joaquin River consists of four 110-in diameter steel 

pipes through the dam controlled by four 96-in hollow jet valves at the 

downstream end with two18-in needle valves branching from two of the 110-in 

valves. The Friant–Kern Canal outlet consists of four 110-in diameter steel pipes 

 

1

The definition of such terms as Ahydraulic height,@ Astructural 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. Unless otherwise noted, all elevations based on the original project datum established by 

U.S. Bureau of Reclamation that was reported to be 2.582 feet lower than the North American Vertical 

Datum of 1988 (NAVD88). 

2
through the dam controlled by four 96-in hollow-jet valves. The Madera Canal 

outlet consists of two 91-in diameter steel pipes through the dam controlled by 

two 86-in valves. The total discharge capacity of the combined outlets is 16,400 

cfs at reservoir elevation 578.0. 

Summary and Conclusions 

This Reclamation report presents the 2004 results of the survey of Millerton Lake. 

The primary objective of the survey was to gather data to: 

 $ develop reservoir topography 

 $ compute area-capacity relationships 

There was a control network established for the 2001 aerial survey of Millerton 

Lake, but no control markers near the dam were easily accessible. The 

hydrographic survey crew conducted a real-time kinematic (RTK) global 

positioning system (GPS) survey utilizing horizontal and vertical control 

established by the National Geodetic Survey (NGS) to tie the 2004 underwater 

data collection to the NGS network. The survey was conducted on July 6, 2004 

with the base set at NGS datum “HPGN D CA 06 RG.” This point was tied to a 

brass cap marked “604.16” that was located near the dam’s left abutment. The 

horizontal control was in California state plane Zone 4 in the North American 

Datum of 1983 (NAD83) and the vertical control was tied to the Reclamation 

project datum elevation that was 604.16 at the brass cap. The National American 

Vertical Datum of 1988 (NAVD88) elevation of this brass cap was 606.742. All 

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

vertical datum that is reported to be 2.582 feet lower than NAVD88. 

The underwater survey, July 7-12, 2004, was conducted between reservoir 

elevation 528.7 and 536.2. The bathymetric survey used sonic depth recording 

equipment interfaced with a real-time kinematic (RTK) and global positioning 

system (GPS) capable of 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 Millerton Lake. 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 

Reclamation reservoir gauge during the time of collection, were used to convert 

the sonic depth measurements to reservoir bottom elevations. These gauge 

elevations were tied to the Reclamation project datum. The contours of Millerton 

Lake were generated with elevations tied to NAVD88 by adding 2.582 feet to the 

Reclamation reservoir gauge elevations. All area and capacity computations 

within this report were tied to the Reclamation datum by reducing the elevations 

of the Millerton Lake surface area results by 2.582 feet. 

3
The 2004 above-water area of Millerton Lake was developed from aerial data 

flown August 28, 2001, near reservoir elevation 496.2. The 2001 Millerton Lake 

aerial data was on tied the NAVD88 and the horizontal coordinates were 

California state plane Zone 4 in NAD83. This aerial survey covered an extensive 

portion of the drainage area above Millerton Lake and a small portion just 

downstream of Friant Dam. The aerial survey x, y, and z coordinates below 

elevation 600 feet where merged with the underwater x, y, and z coordinates to 

develop the new reservoir topography. 

The final 2004 Millerton Lake topography below elevation 590 is a combination 

of the 2001 aerial data 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 using the 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 Millerton Lake and watershed 

characteristics for the 2004 survey. The 2004 survey determined that the 

reservoir has a total storage capacity of 555,763 acre-feet and a surface area of 

5,010 acres at maximum reservoir water surface elevation 585.0 (table 2). 

Reservoir Operations 

Friant Dam operates to provide regulated diversion and downstream flows from 

the San Joaquin River. The July 2004 capacity table shows 555,763 acre-feet of 

total storage below the maximum water surface elevation 585.0 feet (table 2). 

The 2004 survey measured a minimum lake bottom elevation of 287.4 feet. The 

following values are from the July 2004 capacity table: 

$ 34,281 acre-feet of surcharge between elevation 578.0 and 585.0 feet. 

$ 390,262 acre-feet of joint use between elevation 466.3 and 578.0 feet. 

$ 43,944 acre-foot of active storage between elevation 442.2 and 466.3 feet. 

$ 69,889 acre-foot of inactive storage between elevation 375.4 and 442.2 feet. 

$ 17,387 acre-foot of dead storage below 375.4 feet. 

Millerton Lake computed annual inflow and reservoir stage available records are 

listed by water year on table 1 for the operation period 1944 through 2004. The 

inflow values were computed by the Mid-Pacific Regional office and show annual 

fluctuation with a computed average inflow of 1,756,500 acre-feet per year. 

Table 1 also lists the maximum and minimum end-of-month elevation by water 

year. The maximum reservoir elevation was 580.0 recorded on January 3, 1997 

with a minimum elevation of 467.8 recorded on April 11, 1969 (USGS, 2003).

4
5

1. 2. San Joaquin River 3. STATE: California

4. 5. Friant 6. COUNTY: Fresno

7. ° 00 ' 00 " ° 42 ' 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. 5 22. 6

19. NET SEDIMENT CONTRIBUTING AREA 5 23. MEAN ANNUAL RUNOFF 7

20. LENGTH MILES AVG. WIDTH MILES 24. MEAN ANNUAL RUNOFF 7 ACRE-FEET

21. 25. °F °F6

26. DATE OF 27. 28. 29. 30. 31. C/

26. DATE OF 35. 36

7

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.

7/04 10

2/44

10

b. AVG. ANN. c. /MI.2

-YR.

a. 

107,144,600

MEAN ANN. b. TOTAL

1,756,500

10

100

105-

E 

A 7/04

125

115-

105 111 115 120

PERCENT OF TOTAL SEDIMENT LOCATED WITHIN DEPTH DESIGNATION

0- 110- 120-

PER.

34.

R

PER.

ELEVATION

1,638

Contour (D)

526

DEAD

TOP OF POOL

FLOOD CONTROL

POWER

585.0

LONG 119

SURCHARGE

INACTIVE

STORAGE

ALLOCATION

466.3

JOINT USE

CONSERVATION

578.0

13.6

DEPTH DESIGNATION RANGE BY RESERVOIR ELEVATION

8.9

90

70-

80

10- 20- 30- 60- 80-

70

50-

REACH DESIGNATION PERCENT OF TOTAL ORIGINAL LENGTH OF RESERVOIR

 

90- 100-

10 20 30 40 60

PERCENT OF TOTAL SEDIMENT LOCATED WITHIN REACH DESIGNATION

 

YRS YRS

0.30 8

 

AVG. ANN.

 

107,144,600

TOP OF DAM ELEVATION:

4,900

MILES

1,756,500

INCHES

20.1

0.55

SURFACE AREA, AC-FT

5-ft

D

A TWP. 11 S RANGE

Bureau of Reclamation

21 E

R

E

S

E

TOTAL

ORIGINAL 13. ORIGINAL 

5,110

8

37

OWNER:

SEC

LAT

5

M

STREAM:

NEAREST P.O.

S

R

V

O

I

R

B

A

35,000

390,000

2,125

1,756,500 4,704,000

MEAN ANNUAL PRECIPITATION

SQUARE MILES

SQUARE MILES

 

b. MAX. ANN.

PERIOD WATER INFLOW, ACRE-FEET

c.

4,810 9 3-ft

4,900

521,482 9

520,500

33.

RATIO AF/AF

0.30

c.

TOTAL SEDIMENT DEPOSITS TO DATE, AF

 

a. AVG. ANNUAL

 /MI. a. 2

-YR.

D

PERIOD

TYPE OF 

SURVEY

a. MEAN ANN.

Contour (D)

ANNUAL

PRECIPITATION

SURVEY

7/04

a.

a. TOTAL b.

MAX. ELEVATION 14,000 ANNUAL TEMP, MEAN °F RANGE

26.

CAPACITY

WATER INFLOW TO DATE, AF

SURVEY

PERIOD CAPACITY LOSS, ACRE-FEET

TOTAL

PERIOD

U

DATE

OF

SURVEY

A

T

Y

SURVEY

SURVEY

26. 44.

DATE

OF

SURVEY

RESERVOIR SEDIMENT

DATA SUMMARY

Millerton Reservoir NAME OF RESERVOIR 1

DATA SHEET NO.

DATE

STORAGE

581.25

14.

560.0

ACRE-FEET

130,500

86,700

17,400

442.2

375.4

1,580

BEGAN

DATE NORMAL

2/1944

OPERATIONS

2/1944

to 116

636

MILES AVG. WIDTH OF RESERVOIR

MIN. ELEVATION 560 64 17

V 

I

N

S

7/04

555,500

 

AREA, AC. ACRE - FEET

520,500

69,300

17,400

43,800

BEGAN

TOTAL DRAINAGE AREA

INCHES

NO. OF

RANGES OR 

INTERVALS

SURFACE 32.

Table 1 - Reservoir sediment data summary (1 of 2). 
6

1

2

3

4

5

6

7

8

9

10

1954 577.3 469.8 1,300,200 1955 576.8 470.1 1,148,100

1,817,800

1952 562.0 471.2 2,789,800 1953 570.5 472.4 1,275,600

1,314,800 1951 563.2 428.5

552.7 451.0 1,177,900

1948 568.1 442.5 1,139,800 1949 562.1 434.6 1,209,200

1946 561.2 492.6 1,740,200 1947

1950 560.0 406.6

2000

1966 569.7 479.3

566.4 476.8

578.1 498.0

1,413,400

1982 579.2 481.8 3,140,300 1983 579.0 468.2 4,704,000

1,164,800 2003 574.1 499.8

24

1976 547.2 474.3 828,000 1977 511.8 489.9 377,700

310.0 2 8 315.0 7 27 320.0

495.0 202,567 500.0 2,970

3,517 339

160

222 2,257 345.0 278 350.0

578.7 483.8 3,128,500

285 330.0 335.0

1,944,900

1964 555.1 469.4 1,121,300 1965 562.1 475.7 2,028,900

575.3 473.4 1,417,100

1962 561.4 468.3 1,725,000 1963 579.5 477.3

467.8 3,798,300

1970 1,515,300 1971

1968 522.8 460.3 1,135,100 1969

0

521,482

2,718 188,676

45. RANGE IN RESERVOIR OPERATION

1998 579.7 479.7

2002 576.3 481.0

580.0 4,854 531,146

570.0

510.0 3,213

540.0

525.0

248,013

438,665

585.0 5,010 555,763

560.0 4,391

575.0 4,763

555.0 4,276

317,199

545.0 4,051 375,365

530.0 3,703

3

515.0 3,335 264,381

1,307

5,054

217,105

102

300.0 0 1 305.0 1

355,397

416,999

483,737

103 649

2004 CAPACITY

ELEVATION AREA

287.4 0 290.0 0

CAPACITY ELEVATION AREA CAPACITY

2004 567.4 498.4 1,145,200

1997

1999

2001

503.9 1,636,800

579.4 493.8

1,707,900

577.2 488.5 3,584,000

3,072,400

2,832,100

486.3 1,120,400

578.7

575.6

1996 576.6 507.1 2,337,200

1994 560.1 476.0 1,011,700

1992 565.2 480.3 890,600 1993 577.9 475.3 2,456,300

469.7 927,100

1990 539.8 469.5 766,500 1991 554.5 477.9 925,200

539.9 473.0 825,500 1989 547.2

1,215,500

1986 576.8 477.9 2,922,400 1987 532.7 471.0 1,000,200

559.1 480.8 1,140,000

1984 573.7 480.2 2,096,100 1985 557.9 475.4

571.3 469.4 1,797,900

1978 475.0 3,041,500 1979 577.2 481.0 1,975,800

647,100

1972 473.6 1,043,400 1973 579.7 472.3 2,003,300

467.8

577.9

567.4

1960 535.2 471.0

468.0 2,834,400 1957 1,371,800

1958 579.0 477.9 2,568,200 1959 565.2 471.5 1,132,100

1956

1995

478.9

863,000 1961 543.8

578.5

470.0 2,200,000

1,370,700 1967

375.0 629

1975

478.3 2,925,500 1981

395,901

370.0

51

569 14,141

3,458

490.0

397

0

232,254

281,364

336,007

20,404

526.6 1945 561.0 453.5

MIN. ELEV. INFLOW, AF

379.6 1,264,600 2,109,200

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

All elevations are in feet based on the original project datum that is 2.582 feet lower than NAVD88. Top of parapet wall elevation 585.0.

Spillway crest elevation 560.0. Located in center of dam, controlled by drum gates with top elevation 578.0.

Values from Reservoir Capacity Allocation table dated 5/69.

Bureau of Reclamation Project Data Book, 1981. Values for Central Valley Project.

Mean annual runoff of 1,756,500 AF, item 24, from 1944 through 2004 from Reclamation's Mid Pacific Region's computed inflows. Values 

Surface area and capacity at elevation 578.0, spillway crest elevation.

 account for additional inflow from diversion flows. End of month maximum and minimum elevations from USGS annual reports.

 Thomas A. Edison Lake (92 mi2

), Huntington Lake (81 mi2), Bass Lake (49 mi2), Shaver Lake (30 mi2), and Mammoth Pool Reservoir (81 mi2).

7

1944

295.0

505.0

520.0

535.0

578.0

YEAR MAX. ELEV.

49. Bureau of Reclamation March 2005

All 2004 capacities computed by Reclamation's ACAP computer program.

Due to difference of detail between original and 2004 surveys, computing capacity loss due to sediment deposition by 

 comparing differences is not possible.

48. AGENCY MAKING SURVEY Bureau of Reclamation

AGENCY SUPPLYING DATA DATE

4,163

4,810

Reservoir length at elevation 578.

Total drainage area from USGS water year records. Upstream reservoirs capture some of the sediment runoff. Florence Lake (173 mi2

),

507,151

3,820

550.0

410.0

440.0

340.0

325.0

SURVEY

3,090

355.0

0

46. ELEVATION - AREA - CAPACITY - DATA FOR

2004 0

539.6

ELEVATION AREA CAPACITY

576.0

570.1

578.7

1974

1980

1988

6,899 360.0 452 9,020 365.0 514

2,475

17,134

727 23,916

11,431

475.0 2,349 150,646 162,711 485.0 2,596 175,388

375.4 633 17,387

380.0 678 385.0 390.0 791 27,700

395.0 854 31,816 400.0 913 36,234 405.0 971 40,944

1,036 45,962 415.0 1,103 51,305 420.0 1,174 56,994

425.0 1,253 63,060 430.0 1,339 69,535 435.0 1,430 76,456

1,531 83,863 442.2 1,571 87,276 445.0 1,622 91,744

450.0 1,721 100,096 455.0 1,831 108,971 460.0 1,952 118,423

465.0 2,078 128,494 466.3 2,115 131,220 2,216

4,622

470.0

480.0

3,935

3,586 298,973

2,841

47. REMARKS AND REFERENCES

139,233

565.0 4,507 460,913

Table 1 – Reservoir sediment data summary (2 of 2). 
7

1 2 345 6 7 8

2004 2004 Percent of

Elevations Original Original 2004 2004 Area Volume Reservoir

Survey Capacity Survey Survey Difference Difference Depth

(feet) (acres) (acre-feet) (acres) (acre-feet) (acres) (acre-feet)

585.0 5110 555500 5010 555763 100 -263 100.0

580.0 4951 530402 4854 531146 97 -744 98.3

578.0 4900 520528 4810 521482 90 -954 97.7

570.0 4699 482151 4622 483737 77 -1586 95.0

560.0 4433 436485 4391 438665 42 -2180 91.7

550.0 4176 393446 4163 395901 13 -2455 88.3

540.0 3922 352956 3935 355397 -13 -2441 85.0

530.0 3682 314940 3703 317199 -21 -2259 81.7

520.0 3432 279364 3458 281364 -26 -2000 78.3

510.0 3185 246285 3213 248013 -28 -1728 75.0

500.0 2943 215645 2970 217105 -27 -1460 71.7

490.0 2695 187455 2718 188676 -23 -1221 68.3

480.0 2454 161720 2475 162711 -21 -991 65.0

470.0 2211 138389 2216 139233 -5 -844 61.7

466.3 2125 130437 2115 131220 10 -783 60.4

460.0 1957 117539 1952 118423 5 -884 58.3

450.0 1700 99274 1721 100096 -21 -822 55.0

442.2 1580 86707 1571 87276 9 -569 52.4

440.0 1493 83337 1531 83863 -38 -526 51.7

430.0 1311 69339 1339 69535 -28 -196 48.3

420.0 1160 57000 1174 56994 -14 6 45.0

410.0 1025 46087 1036 45962 -11 125 41.7

400.0 910 36432 913 36234 -3 198 38.3

390.0 797 27885 791 27700 6 185 35.0

380.0 689 20457 678 20404 11 53 31.7

375.4 636 17412 633 17387 3 25 30.1

370.0 574 14134 569 14141 5 -7 28.3

360.0 452 8960 452 9020 0 -60 25.0

350.0 329 4977 339 5054 -10 -77 21.7

340.0 216 2282 222 2257 -6 25 18.3

330.0 103 675 103 649 0 26 15.0

320.0 23 93 24 102 -1 -9 11.7

310.0 2 4 2 8 0 -4 8.3

287.4 0 0 0 0 0 0 0.8

285.0 0 0 0 0 0 0 0.0

1 Elevation of reservoir water surface.

2 Original reservoir surface area.

3 Original reservoir capacity recomputed using ACAP.

4 Reservoir surface area from 2004 survey.

5 Reservoir capacity computed using ACAP.

6 Area difference between original and 2004 survey = column (3) - column (5).

7 Volume difference between original and 2004 survey = column (4) - column (5).

8 Depth of reservoir expressed in percentage of total depth of 300.0 feet.

Table 2 - Summary of 2004 survey results. 
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 3). 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. 

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 

California’s state plane Zone 4 coordinates in NAD83. The RTK GPS system 

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

differential GPS. 

Figure 3 - Survey vessel with mounted instrumentation on Jackson Lake in Wyoming.

In 2001, the Sedimentation and River Hydraulics Group began utilizing an 

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 generate a detailed cross 

8
section of bottom geometry as the survey vessel passes over the areas to be 

mapped. The system transmits 80 separate 1-1/2 degree slant beams resulting in a 

120-degree swath from the transducer. The 200 kHz high-resolution multibeam 

echosounder system measured the relative water depth across the wide swath 

perpendicular to the vessel’s track. Figure 4 illuminates the swath of the sea floor 

that is about 3.5 times the water depth below the transducer. 

Figure 4 - 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 

include the RTK GPS for positioning; a motion reference unit to measures the 

heave, pitch, and roll of the survey vessel; a gyro to measures the yaw or vessel 

attitude; and a velocity meter to measure the speed of sound of the reservoir water 

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

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

bottom. 

The Millerton Lake bathymetric survey collection was conducted from July 7 

through July 12 of 2004 between water surface elevation 528.7 and 536.1 

(Reclamation project datum). The survey was run using the multibeam 

instrumentation described above where the survey system software continuously 

recorded reservoir depths and horizontal coordinates as the survey vessel moved 

across close-spaced grid lines covering the reservoir area. Most of the transects 

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

multibeam swaths overlapped each other. The multibeam system could have 

provided full bottom coverage of the area not covered by the aerial collection, but 

time, budget, and access did not allow this to occur in all the shallow portions of 

the reservoir. The loss of these additional data points did not have a significant 

9
impact on the area computations since it only occurred in a few areas of the 

reservoir. 

The data analysis began 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 field measured sound 

velocity of the reservoir water column and then converting all corrected depth 

data to elevations. All elevations in the final analysis were tied to the 

Reclamation measured water surface elevation at the time of collection. These 

water surface elevations were converted to NAVD88 datum by adding 2.582 feet. 

Due to the massive amount of data, the data was filtered utilizing built-in 

procedures within the collection and analysis software that logically filtered data 

points without adversely affecting the results. Quality control and assurance of 

the data were accomplished by conducting field calibration as required by the 

multibeam system and collecting velocity profile data for the areas being 

surveyed. 

Reservoir Area and Capacity 

Topography Development 

The topography of Millerton Lake was developed from the 2004 underwater and 

the 2001 aerial data. The 2001 aerial data was in an x, y, and z format, California 

state plane Zone 4 in NAD83, from around elevation 496.2 and above. The 2001 

aerial data elevations were tied to NAVD88 for the survey of Millerton Lake. 

Due to the large data set, all elevations below elevation 496 and above elevation 

600 were removed. Additionally, all aerial data downstream of the dam was also 

removed. Using the aerial data a hardclip was developed to enclose all of the 

reservoir data. This hardclip was used during the triangular irregular network 

(TIN) development so interpolation did not occur outside the enclosed polygon. 

This clip was not assigned an elevation and was strictly used to enclose the 2001 

and 2004 data sets. 

Contours for the reservoir within this hardclip were computed from the combined 

aerial and underwater data sets using the triangular irregular network (TIN) 

surface-modeling package within ARC/INFO. A TIN is a set of adjacent, nonoverlapping 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 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 

10
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 Millerton Lake 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 Millerton Lake since 

the areas were calculated from the developed TIN. The areas of the enclosed 

contour polygons at one-foot increments were developed from the combined 

survey data sets. The 2004 contour topography is presented on figures 5 through 

figure 9. The contour data presented on these maps are tied to the vertical datum 

of NAVD88. All computations within this report are tied to the Millerton Lake 

project datum that is 2.582 feet lower than NAVD88. 

Development of the 2004 Contours 

The 2004 contours of Millerton Lake were developed by combining the 2001 

aerial and 2004 underwater data. The reservoir contours are presented on the 

included maps (figures 5 through 9) at 10-foot increments from elevation 290.0 

through elevation 590.0. As stated previously the contours presented on these 

maps are tied to NAVD88 which is 2.582 feet higher than the project datum and 

the horizontal coordinates were on the California State Plane, Zone 4, in NAD83. 

Development of the 2004 Surface Areas 

The 2004 contour surface areas for Millerton Lake were computed at 1-foot 

increments from Millerton Lake TIN. Since the TIN was developed from 

elevations tied to NAVD88, the resultant elevation versus surface area table was 

shifted down 2.582 feet to match the project datum elevations. The final table had 

measured results from project elevation 288.0 through elevation 585.0. The 2004 

underwater survey measured a minimum reservoir bottom elevation of 287.4. 

Surface area calculations were performed using the ARC/INFO VOLUME 

command that computes areas at user-specified elevations directly from the TIN 

and takes into consideration all regions of equal elevation. 

11
12
13
14
15
16
17
18
19
20
21
22
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). For the purpose of this study, the measured 2004 survey 

areas at 3-foot increments from elevation 290.0.0 through 590.0 were used to 

compute the new area and capacity tables and were used as the control parameters 

for computing the 2004 Millerton Lake capacity. The ACAP 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 the Millerton Lake data analysis. 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 shorter 

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 + a3x

2 

 where: y = capacity 

x = elevation above a reference base 

a1 = intercept 

a2 and a3 = coefficients 

Results of the Millerton Lake area and capacity computations are listed in a 

separate set of 2004 area and capacity tables that have been published for the 

0.01, 0.1 and 1-foot elevation increments (Bureau of Reclamation 2004). A 

description of the computations and coefficients output from the ACAP program 

is included with these tables. The 1945 and 2004 area-capacity curves are listed 

on table 2 and plotted on figure 10. As of July 2004, at spillway top of gate 

elevation 578.0, the surface area was 4,810 acres with a total capacity of 521,482 

acre-feet. 

2004 Reservoir Analyses 

Results of the Millerton Lake area and capacity computations are listed in table 1 

and columns 4 and 5 of table 2. As stated previously, unless otherwise noted, all 

elevations in this report are based on the original project datum established by 

Reclamation that is reported to be 2.582 feet lower than NAVD88. Columns 2 

23
and 3 of table 2 list the 1945 or original area and capacity values for Millerton 

Lake. Columns 6 and 7 list the surface area and capacity differences between the 

original and 2004 computations. Figure 10 is a plot of the Millerton Lake surface 

area and capacity values for the two surveys and illustrates the small differences. 

The comparison show the reservoir capacity in 2004 is slightly greater than the 

original capacity from around reservoir elevation 430 and higher. 

Research into the original values found that the surface areas were calculated by 

the Division of Water Resources in January 1936 based on topographic maps of 

the reservoir prepared by the Madera Irrigation District from a survey conducted 

in 1921. The contour interval was 10 feet and maps were at a scale of one-inch 

equals two hundred feet. Information on how this survey was conducted was not 

located, but it is assumed it was a plane table type collection requiring many staff 

days to traverse the rugged terrain and resulting in less detail than the 2004 

survey. 

During the original planning of Millerton Lake, the estimated loss of total 

reservoir capacity over the first 100 years of operation was 7.9 percent or around 

41,000 acre-feet. There is no information on how this sediment inflow value was 

determined and what factors were utilized. This investigation found that the total 

drainage area into Millerton Lake is around 1,638 square miles and if it assumed 

all the upstream reservoirs capture sediment inflow, then only around 526 square 

miles of the drainage area contributes sediment inflow directly into Millerton 

Lake. It is unknown if the original planning process took into account these 

upstream reservoirs even though most existed prior to Friant Dam closure. Due to 

all of these unknowns, there are no means from the 2004 survey results to 

estimate reservoir sediment deposition since dam closure. 

It is the general conclusion the small capacity difference between the original and 

2004 surveys is due to the differences in detail of the surveys. The 2004 detailed 

survey resulted in a more accurate representation of the reservoir volume as of 

July 2004. Even though the sediment contributing area is only about 32 percent 

of the total drainage basin, one would still anticipate annual capacity loss due to 

sediment inflow. If sediment inflow is a concern, then collection of reservoir 

bottom samples along with depth profiles from a low frequency sounder could 

possibly measure the thickness of any existing reservoir bottom sediments.

24
25

Area-Capacity Curves for Millerton Lake

285.0305.0325.0345.0365.0385.0405.0425.0445.0465.0485.0505.0525.0545.0565.0585.0

0 56000 112000 168000 224000 280000 336000 392000 448000 

Capacity (acre-feet)

Elevation (feet)

5000 4500 4000 3500 3000 2500 2000 1500 1000 

2004 SurveyOriginal Survey

Area

Capacity

Area (acre)

Figure 10 - 2004 area and capacity curves. 
References 

American Society of Civil Engineers, 1962. Nomenclature 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 of Small Dams, U.S. Government 

Printing Office, Denver CO. 

Bureau of Reclamation, July 2004. Denver Office, Millerton Lake Area and 

Capacity Tables, Central Valley 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.mil/inet/usace-docs/eng-manuals/em1110-2-1003/toc.htm). 

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

References. 

United States Geological Survey (USGS), 2003. Water Resources Data Nevada 

Water Year 2003, Water-Data Report NV-03-1, U.S. Geological Survey, Carson 

City, NV. 

26