COLORADO RIVER MAIN STEM

09018500 LAKE GRANBY NEAR GRANBY, CO

LOCATION.--Lat 40°10'55", long 105°52'14", in NW14NE14, sec.35, T.3 N., R.76 W., Grand County, Hydrologic Unit 14010001, in Granby pumping plant at north shore of lake, 2.5 mi north of Granby Dam on Colorado River and 7.5 mi northeast of Granby.

DRAINAGE AREA.--312 mi2.

RESERVOIR ELEVATIONS AND CONTENTS RECORDS

PERIOD OF RECORD.--October 1949 to current year. Prior to October 1955, published as Granby Reservoir near Granby. For a complete listing of historical data available for this site, see http://waterdata.usgs.gov/co/nwis/inventory/?site_no=09018500

REVISED RECORDS.--WSP2124: Drainage area.

GAGE.--Water-stage recorder. Datum of gage is above NGVD of 1929, (levels by U.S. Bureau of Reclamation); gage readings have been reduced to elevations above NGVD of 1929. Prior to Apr. 9, 1951, nonrecording gage at dam at present datum.

REMARKS.--Lake is formed by earthfill dam and dikes. Regulation began Sept. 13, 1949, and usable storage began June 14, 1950, while dam was under construction. Usable capacity, 465,600 acre-ft, between elevations 8,186.00 ft, trash rack sill at outlet, and 8,280.00 ft, top of radial spillway gates. Dead storage, 74,190 acre-ft. Figures given represent usable contents. Lake is used to store water for pumping to Shadow Mountain Lake for transmoutain diversion through Alva B. Adams tunnel for power and irrigation in South Platte River basin. Water-quality data for this site is included under the Three Lakes Water-Quality Study section of this report.

COOPERATION.--Records provided by U.S. Bureau of Reclamation.

EXTREMES FOR PERIOD OF RECORD.--Maximum contents, 465,900 acre-ft, July 13, 1962, elevation, 8,280.05 ft; minimum since appreciable storage was attained, 13,070 acre-ft, Apr. 16, 1978, elevation, 8,190.93 ft.

EXTREMES (AT 0800) FOR CURRENT YEAR.--Maximum contents, 328,800 acre-ft, July 30, elevation, 8,259.88 ft; minimum, 14,720 acre-ft, Mar. 17, elevation, 8,191.52 ft.

MONTHEND ELEVATION AND CONTENTS, AT 0800, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003

Date	Elevation (feet)	Contents (acre-feet)	Change in contents (acre-feet)
Sept. 30. . . . . . . . . . . . . . . . . . . . . . . . .	8,216.64	102,500	-
Oct. 31 . . . . . . . . . . . . . . . . . . . . . . . . .	8,217.39	105,600	+3,110
Nov. 30 . . . . . . . . . . . . . . . . . . . . . . . . .	8,212.29	84,910	-20,700
Dec. 31 . . . . . . . . . . . . . . . . . . . . . . . . .	8,205.52	59,460	-25,450
CAL YR 2002. . . . . . . . . . . . . . . . . . . .	-	-	-183,800
Jan. 31 . . . . . . . . . . . . . . . . . . . . . . . . .	8,198.33	35,130	-24,330
Feb. 28 . . . . . . . . . . . . . . . . . . . . . . . . .	8,194.34	22,860	-12,280
Mar. 31 . . . . . . . . . . . . . . . . . . . . . . . . .	8,192.00	16,060	-6,800
Apr. 30 . . . . . . . . . . . . . . . . . . . . . . . . .	8,199.04	37,410	+21,350
May 31. . . . . . . . . . . . . . . . . . . . . . . . . .	8,228.74	156,300	+118,900
June 30 . . . . . . . . . . . . . . . . . . . . . . . . .	8,256.56	308,100	+151,800
July 31 . . . . . . . . . . . . . . . . . . . . . . . . .	8,259.75	328,000	+19,810
Aug. 31 . . . . . . . . . . . . . . . . . . . . . . . . .	8,256.95	310,500	-17,420
Sept. 30. . . . . . . . . . . . . . . . . . . . . . . . .	8,254.87	297,800	-12,690
WTR YR 2003. . . . . . . . . . . . . . . . . . .	-	-	+195,300