B120UP.201103 (03/24/11 1317)
DEPARTMENT OF WATER RESOURCES
California Cooperative Snow Surveys
WATER SUPPLY FORECAST UPDATE
2011 April-July Unimpaired Runoff (1,000 Acre-feet)
Mar 1 %Avg Mar 8 %Avg Mar 15 %Avg Mar 22 %Avg
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Shasta Lake, Total Inflow average = 1819
90% Exceedance 1160 64% 1270 70% 1360 75% 1670 92%
50% Exceedance 1600 88% 1690 93% 1760 97% 2050 113%
10% Exceedance 2500 137% 2570 141% 2610 143% 2880 158%
Sacramento River, above Bend Bridge (near Red Bluff) average = 2494
90% Exceedance 1540 62% 1690 68% 1830 73% 2270 91%
50% Exceedance 2170 87% 2300 92% 2410 97% 2830 113%
10% Exceedance 3600 144% 3670 147% 3720 149% 4080 164%
Feather River at Oroville average = 1782
90% Exceedance 1180 66% 1390 78% 1580 89% 2130 120%
50% Exceedance 1780 100% 1940 109% 2080 117% 2580 145%
10% Exceedance 2930 164% 3020 170% 3090 173% 3530 198%
Yuba River near Smartsville average = 1006
90% Exceedance 790 79% 880 88% 950 94% 1250 124%
50% Exceedance 1150 114% 1220 121% 1270 126% 1550 154%
10% Exceedance 1720 171% 1750 174% 1760 175% 2000 199%
American River, below Folsom Lake average = 1240
90% Exceedance 950 77% 1110 90% 1200 97% 1620 131%
50% Exceedance 1400 113% 1520 123% 1570 127% 1950 157%
10% Exceedance 2230 180% 2310 186% 2320 187% 2660 215%
Mokelumne River, Inflow to Pardee Reservoir average = 461
90% Exceedance 420 91% 470 102% 490 106% 580 126%
50% Exceedance 540 117% 580 126% 590 128% 670 145%
10% Exceedance 780 169% 800 174% 790 171% 850 184%
Stanislaus River, below Goodwin Res. (blw New Melones) average = 702
90% Exceedance 680 97% 740 105% 750 107% 880 125%
50% Exceedance 850 121% 900 128% 900 128% 1020 145%
10% Exceedance 1240 177% 1260 179% 1230 175% 1320 188%
Tuolumne River, below La Grange Res. (blw Don Pedro) average = 1220
90% Exceedance 1210 99% 1310 107% 1320 108% 1590 130%
50% Exceedance 1470 121% 1550 127% 1540 126% 1790 147%
10% Exceedance 2090 171% 2120 174% 2060 169% 2250 184%
Merced River, below Merced Falls (blw Lake McClure) average = 632
90% Exceedance 630 100% 670 106% 660 104% 820 130%
50% Exceedance 770 122% 800 127% 780 123% 930 147%
10% Exceedance 1120 177% 1130 179% 1080 171% 1210 191%
San Joaquin River, below Millerton Lake average = 1254
90% Exceedance 1350 108% 1420 113% 1400 112% 1630 130%
50% Exceedance 1630 130% 1680 134% 1640 131% 1850 148%
10% Exceedance 2220 177% 2210 176% 2120 169% 2270 181%
Kings River, below Pine Flat Reservoir average = 1224
90% Exceedance 1320 108% 1390 114% 1380 113% 1610 132%
50% Exceedance 1600 131% 1640 134% 1610 132% 1810 148%
10% Exceedance 2190 179% 2160 177% 2070 169% 2200 180%
Kaweah River, below Terminus Reservoir average = 286
90% Exceedance 330 115% 340 119% 330 115% 380 133%
50% Exceedance 390 136% 400 140% 390 136% 430 150%
10% Exceedance 570 199% 570 199% 540 189% 570 199%
Tule River, below Lake Success average = 64
90% Exceedance 65 102% 70 110% 67 105% 83 131%
50% Exceedance 84 132% 88 139% 84 132% 99 156%
10% Exceedance 158 249% 157 247% 147 231% 157 247%
Kern River, inflow to Isabella Lake average = 461
90% Exceedance 540 117% 580 126% 570 124% 650 141%
50% Exceedance 650 141% 680 147% 660 143% 740 160%
10% Exceedance 950 206% 940 204% 880 191% 920 199%
Questions regarding this forecast:
John King: (916) 574-2637 (e-mail kingjj@water.ca.gov)
Steve Nemeth: (916) 574-2634 (e-mail nemeth@water.ca.gov)
Dave Rizzardo: (916) 574-2983 (e-mail daver@water.ca.gov)
Andy Reising: (916) 574-2181 (e-mail areising@water.ca.gov)
Runoff forecasts are unimpaired (full natural) flows which represent the
natural water production of the river basin, unaltered by upstream diversions,
storage, or export or import of water to or from other watersheds.
The median (50%) forecast assumes median conditions after the date of forecast.
Runoff exceedance levels are derived from historical data.
The 90 percent exceedance level and the 10 percent exceedance level together
comprise a range about the median forecast in which the actual runoff should
fall 8 times out of 10.
Forecasts are stated in 1,000's of acre-feet and percent of (50-year) average.
The averages are for the period 1956 to 2005.
