Water-Data Report 2008 10260790 Silverwood Lake near Hesperia, CA Mojave River Basin

LOCATION.--Lat 34°1815, long 117°1905 referenced to North American Datum of 1927, in SW ¼ NE ¼ sec.32, T.3 N., R.4 W., San Bernardino County, CA, Hydrologic Unit 18090208, in San Bernardino National Forest, in control structure, near spillway of Cedar Springs Dam, and 8.7 mi south of Hesperia. DRAINAGE AREA.--34.0 mi². SURFACE-WATER RECORDS PERIOD OF RECORD.--October 1995 to September 2004, October 2005 to current year. Unpublished records for water years 1972-95 available in files of the California Department of Water Resources. GAGE.--Water-stage recorder. Datum of gage is NGVD of 1929. COOPERATION.--Records were collected by California Department of Water Resources, under general supervision of the U.S. Geological Survey, in connection with Federal Energy Regulatory Commission project no. 2426. Contents not rounded to U.S. Geological Survey standards. REMARKS.--Lake is formed by earth-fill dam completed in 1972. Capacity, 74,970 acre-ft, at spillway crest of 3,355 ft. Dead storage at invert of outlet structure, 3,967 acre-ft, elevation, 3,235 ft. Lake is a holding basin for East Branch California Aqueduct. See REMARKS for station 10260820. See schematic diagram of Mojave River Basin available from the California Water Science Center. EXTREMES FOR PERIOD OF RECORD.--(at 2400 hours) Maximum contents, 74,853 acre-ft, Dec. 27, 2003, elevation, 3,354.88 ft; minimum contents, 38,006 acre-ft, Mar. 22, 1996, elevation, 3,310.24 ft. EXTREMES FOR CURRENT YEAR.--(at 2400 hours) Maximum contents, 74,848 acre-ft, Dec. 25, elevation, 3,354.87 ft; minimum contents, 68,493 acre-ft, Sept. 13, elevation, 3,348.13 ft.

Capacity table (elevation, in feet, and contents, in acre-feet) (Based on table provided by California Department of Water Resources, dated January 1978) Elevation Contents Elevation Contents Elevation Contents 3,300 31,395 3,325 48,732 3,345 65,554 3,315 41,311 3,335 56,811 3,355 74,970

U.S. Department of the Interior U.S. Geological Survey Water-Data Report 2008 10260790 Silverwood Lake near Hesperia, CA—Continued

RESERVOIR STORAGE, ACRE FEET WATER YEAR OCTOBER 2007 TO SEPTEMBER 2008 DAILY OBSERVATION AT 2400 HOURS Day Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

1 72,465 71,501 72,140 72,599 74,065 71,987 72,035 71,571 71,397 71,159 69,913 71,720 2 72,121 72,140 72,274 72,599 73,794 72,705 72,006 72,035 70,676 71,207 69,753 72,006 3 72,006 72,360 72,255 72,753 73,842 72,274 71,720 72,226 70,092 70,884 70,648 72,121 4 72,255 73,436 71,853 73,032 73,465 71,758 71,644 72,197 70,045 71,720 70,223 71,558 5 72,121 73,436 70,865 73,465 73,003 71,530 71,663 72,140 69,932 71,207 70,148 71,178 6 72,006 72,226 70,092 73,600 72,551 70,970 71,720 72,523 69,463 71,796 70,092 71,074 7 71,958 72,197 70,648 73,436 72,035 70,913 71,577 72,360 69,276 70,780 70,195 71,634 8 72,063 72,762 71,131 73,003 71,501 69,960 71,501 72,571 70,412 70,120 70,412 71,045 9 72,255 72,551 71,311 72,331 71,473 70,809 71,853 72,551 70,884 70,516 70,412 70,648 10 72,465 72,993 71,558 71,901 71,796 70,752 71,663 72,226 71,930 70,308 71,739 70,223 11 72,035 73,436 71,930 71,397 72,006 70,308 71,720 72,331 72,121 70,016 71,577 69,641 12 71,711 73,060 71,397 71,560 72,048 70,865 71,796 72,417 71,796 68,809 71,606 68,725 13 71,606 73,032 70,837 72,465 71,901 70,601 71,178 72,016 71,397 69,463 71,606 68,493 14 72,417 72,762 71,131 72,417 71,796 70,837 71,292 72,035 70,865 70,903 71,720 68,971 15 72,791 72,551 71,201 72,331 72,121 71,074 71,987 72,006 72,090 70,148 71,292 69,782 16 72,983 72,571 71,501 72,331 73,118 71,949 72,820 71,368 71,825 70,572 70,884 70,045 17 72,897 71,958 71,264 71,930 73,465 71,901 71,958 71,311 71,720 70,063 72,092 70,092 18 73,118 72,302 71,501 71,720 72,897 72,006 72,035 71,853 71,898 70,063 71,853 69,725 19 72,926 72,121 71,444 71,663 72,897 72,121 71,159 71,577 71,501 70,016 71,901 69,014 20 72,705 72,226 71,720 72,754 72,523 72,465 71,530 71,292 70,809 69,988 71,796 68,809 21 72,686 71,901 72,140 72,782 71,930 71,987 71,473 70,998 71,135 71,501 72,092 70,601 22 72,169 72,523 72,436 72,791 71,606 71,397 71,311 70,016 71,112 71,264 72,456 70,601 23 72,121 72,331 73,871 72,389 71,501 71,235 71,473 70,327 71,088 70,970 72,006 70,516 24 72,107 72,705 74,143 72,599 73,003 70,884 71,796 70,733 71,017 70,705 72,743 70,148 25 70,487 72,791 74,848 72,762 73,003 70,516 71,311 71,340 71,207 70,601 72,599 69,641 26 69,960 72,686 74,278 73,032 72,551 70,601 71,473 72,197 70,728 70,601 72,302 69,117 27 69,800 72,465 73,224 73,842 71,720 70,733 71,235 72,255 70,704 71,292 72,006 69,014 28 70,998 72,235 72,983 73,272 71,102 70,308 71,397 71,987 70,752 70,648 71,397 70,648 29 72,053 72,571 72,571 73,821 71,264 70,355 71,720 71,987 71,159 70,544 71,017 70,705 30 71,264 72,121 72,571 73,929 --- 71,720 71,577 71,825 71,045 70,384 70,705 70,941 31 71,368 --- 72,571 73,978 --- 72,063 --- 71,606 --- 70,176 72,006 --- Max 73,118 73,436 74,848 73,978 74,065 72,705 72,820 72,571 72,121 71,796 72,743 72,121 Min 69,800 71,501 70,092 71,397 71,102 69,960 71,159 70,016 69,276 68,809 69,753 68,493 Elevation, in feet, at end of month 3,351.26 3,352.05 3,352.52 3,353.98 3,351.15 3,351.99 3,351.48 3,351.51 3,350.92 3,350.00 3,351.93 3,350.81 Change in contents, in acre feet -2,068 +753 +450 +1,407 -2,714 +799 -486 +29 -561 -869 +1,830 -1,065

Calendar Year 2007 Water Year 2008 Max 74,848 74,848 Min 47,097 68,493 Change in contents, in acre feet +316 -2,495

— 2 — Water-Data Report 2008 10260790 Silverwood Lake near Hesperia, CA—Continued

75,000

74,000

73,000

72,000

71,000

70,000 OBSERVATION AT 2400 HOURS RESERVOIR STORAGE, ACRE FEET, RESERVOIR STORAGE, ACRE

69,000

68,000 O N D J F M A M J J A S 2007 2008

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