Water-Data Report 2011 11277100 Diversion Tunnel to , near , CA San Joaquin River Basin

LOCATION.--Lat 37°58′47″, long 119°52′51″ referenced to North American Datum of 1927, in SW ¼ SW ¼ sec.34, T.2 N., R.19 E., Tuolumne County, CA, Hydrologic Unit 18040009, , on west side of Lake Eleanor, 0.5 mi northwest of Eleanor Dam, and 6.0 mi northwest of Hetch Hetchy .

SURFACE-WATER RECORDS PERIOD OF RECORD.--July 1996 to August 1996, October 1996 to September 1999, November 2000 to September 2001, October 2002 to current year. GAGE.--Ultrasonic-velocity meter system. Elevation of gage is 4,670 ft above NGVD of 1929, from topographic map. REMARKS.--Records fair. Flow is gravity flow or regulated by pump station at Cherry Lake (station 11277200). Diversion from Lake Eleanor (station 11277500) to Cherry Lake began in March 1960. See schematic diagram of Basin available from the Water Science Center. EXTREMES FOR PERIOD OF RECORD.--Maximum daily discharge, 816 ft³/s, Feb. 17, 2001; no flow at times each year.

U.S. Department of the Interior U.S. Geological Survey Water-Data Report 2011 11277100 Lake Eleanor Diversion Tunnel to Cherry Lake, near Hetch Hetchy, CA—Continued

DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2010 TO SEPTEMBER 2011 DAILY MEAN VALUES [e, estimated] Day Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

1 0.00 e108 219 e0.00 246 297 0.00 0.00 0.00 0.00 141 156 2 0.00 249 218 e0.00 247 297 0.00 0.00 0.00 0.00 138 149 3 0.00 248 218 e132 247 298 0.00 0.00 0.00 0.00 142 e62 4 e0.00 246 217 262 251 302 0.00 0.00 0.00 0.00 137 0.00 5 e0.00 244 219 259 252 304 0.00 0.00 0.00 0.00 140 0.00 6 0.00 237 220 257 255 302 0.00 0.00 0.00 0.00 138 0.00 7 e0.00 240 223 257 257 305 0.00 0.00 0.00 0.00 140 0.00 8 e102 229 219 254 259 307 0.00 0.00 0.00 0.00 139 0.00 9 200 228 e219 253 262 311 0.00 0.00 0.00 0.00 138 0.00 10 200 e227 e110 252 264 311 0.00 0.00 0.00 0.00 135 0.00 11 198 226 e0.00 250 267 312 0.00 0.00 0.00 0.00 135 0.00 12 198 227 0.00 255 268 314 0.00 0.00 0.00 0.00 135 0.00 13 195 224 0.00 248 271 314 0.00 0.00 0.00 0.00 138 0.00 14 193 221 0.00 255 270 316 0.00 0.00 0.00 0.00 138 0.00 15 191 220 e0.00 251 272 317 0.00 0.00 0.00 0.00 136 0.00 16 188 219 0.00 250 274 321 0.00 0.00 0.00 0.00 e143 0.00 17 186 219 e0.00 252 275 327 0.00 0.00 0.00 0.00 139 0.00 18 176 218 e0.00 251 198 327 0.00 0.00 0.00 0.00 141 0.00 19 182 219 e0.00 251 268 325 0.00 0.00 0.00 0.00 145 0.00 20 178 218 e0.00 251 210 322 0.00 0.00 0.00 0.00 147 0.00 21 177 221 e0.00 251 252 e161 0.00 0.00 0.00 0.00 137 0.00 22 175 214 e0.00 250 288 0.00 0.00 0.00 0.00 0.00 140 e0.00 23 176 e214 0.00 247 288 0.00 0.00 0.00 0.00 0.00 144 0.00 24 e176 213 e131 249 290 e0.00 e0.00 0.00 0.00 0.00 148 0.00 25 e176 215 253 249 290 e143 0.00 0.00 0.00 0.00 137 0.00 26 e88 214 256 248 292 e326 0.00 0.00 0.00 e121 e156 0.00 27 0.00 216 255 249 294 e163 0.00 0.00 0.00 e136 148 0.00 28 0.00 216 e255 248 296 0.00 0.00 0.00 0.00 e142 145 e143 29 0.00 101 e254 245 --- 0.00 0.00 0.00 0.00 143 147 e157 30 0.00 129 254 243 --- 0.00 0.00 0.00 0.00 141 152 e163 31 0.00 --- e126 244 --- 0.00 --- 0.00 --- 140 e135 --- Total 3,355.00 6,420 3,866.00 7,163.00 7,403 7,022.00 0.00 0.00 0.00 823.00 4,374 830.00 Mean 108 214 125 231 264 227 0.00 0.00 0.00 26.5 141 27.7 Max 200 249 256 262 296 327 0.00 0.00 0.00 143 156 163 Min 0.00 101 0.00 0.00 198 0.00 0.00 0.00 0.00 0.00 135 0.00 Ac-ft 6,650 12,730 7,670 14,210 14,680 13,930 0.00 0.00 0.00 1,630 8,680 1,650

STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1996 - 2011, BY WATER YEAR (WY) Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Mean 20.3 93.7 170 134 194 259 255 203 81.9 55.9 33.1 10.0 Max 160 264 348 333 308 434 504 550 238 179 141 42.9 (WY) (1999) (2003) (2002) (2002) (1998) (1998) (1998) (1998) (2008) (1999) (2011) (2006) Min 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 (WY) (1997) (1997) (2000) (1997) (1997) (2000) (2006) (2005) (2005) (2001) (1997) (1997)

— 2 — Water-Data Report 2011 11277100 Lake Eleanor Diversion Tunnel to Cherry Lake, near Hetch Hetchy, CA—Continued

SUMMARY STATISTICS Calendar Year 2010 Water Year 2011 Water Years 1996 - 2011 Annual total 37,495.00 41,256.00 Annual mean 103 113 129 Highest annual mean 221 1998 Lowest annual mean 85.0 2010 Highest daily mean 267 Apr 12 327 Mar 17 816 Feb 17, 2001 Lowest daily mean 0.00 Jan 19 0.00 Oct 1 0.00 Oct 1, 1996 Annual seven-day minimum 0.00 Apr 14 0.00 Oct 1 0.00 Oct 1, 1996 Annual runoff (ac-ft) 74,370 81,830 93,730 10 percent exceeds 222 265 329 50 percent exceeds 108 129 55 90 percent exceeds 0.00 0.00 0.00

1,000

500

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100

50 DISCHARGE, CUBIC FEET PER SECOND PER FEET CUBIC DISCHARGE,

MEAN

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10 O N D J F M A M J J A S 2010 2011

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