B120UP.201002 (02/25/10 1217)
DEPARTMENT OF WATER RESOURCES
California Cooperative Snow Surveys
WATER SUPPLY FORECAST UPDATE
2010 April-July Unimpaired Runoff (1,000 Acre-feet)
Feb 1 %Avg Feb 9 %Avg Feb 16 %Avg Feb 23 %Avg
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Shasta Lake, Total Inflow average = 1819
90% Exceedance 1140 63% 1230 68% 1220 67% 1170 64%
50% Exceedance 1620 89% 1690 93% 1670 92% 1610 89%
10% Exceedance 2620 144% 2660 146% 2620 144% 2530 139%
Sacramento River, above Bend Bridge (near Red Bluff) average = 2494
90% Exceedance 1500 60% 1610 65% 1620 65% 1570 63%
50% Exceedance 2200 88% 2290 92% 2280 91% 2210 89%
10% Exceedance 3800 152% 3850 154% 3800 152% 3690 148%
Feather River at Oroville average = 1782
90% Exceedance 850 48% 890 50% 870 49% 860 48%
50% Exceedance 1550 87% 1560 88% 1520 85% 1480 83%
10% Exceedance 2990 168% 2920 164% 2800 157% 2690 151%
Yuba River near Smartsville average = 1006
90% Exceedance 530 53% 540 54% 500 50% 470 47%
50% Exceedance 930 92% 930 92% 880 88% 840 84%
10% Exceedance 1620 161% 1590 158% 1510 150% 1440 143%
American River, below Folsom Lake average = 1240
90% Exceedance 550 44% 570 46% 510 41% 490 40%
50% Exceedance 1080 87% 1080 87% 1010 81% 960 77%
10% Exceedance 2100 169% 2050 165% 1930 156% 1830 148%
Mokelumne River, Inflow to Pardee Reservoir average = 461
90% Exceedance 280 61% 290 63% 280 61% 270 59%
50% Exceedance 440 95% 430 93% 410 89% 390 85%
10% Exceedance 740 161% 710 154% 680 148% 640 139%
Stanislaus River, below Goodwin Res. (blw New Melones) average = 702
90% Exceedance 400 57% 410 58% 400 57% 400 57%
50% Exceedance 650 93% 640 91% 610 87% 580 83%
10% Exceedance 1110 158% 1080 154% 1030 147% 990 141%
Tuolumne River, below La Grange Res. (blw Don Pedro) average = 1220
90% Exceedance 760 62% 780 64% 750 61% 750 61%
50% Exceedance 1170 96% 1150 94% 1080 89% 1040 85%
10% Exceedance 1960 161% 1890 155% 1780 146% 1700 139%
Merced River, below Merced Falls (blw Lake McClure) average = 632
90% Exceedance 400 63% 410 65% 400 63% 390 62%
50% Exceedance 600 95% 600 95% 570 90% 550 87%
10% Exceedance 1060 168% 1030 163% 970 153% 920 146%
San Joaquin River, below Millerton Lake average = 1254
90% Exceedance 900 72% 920 73% 890 71% 870 69%
50% Exceedance 1270 101% 1270 101% 1210 97% 1170 93%
10% Exceedance 2090 167% 2020 161% 1910 152% 1810 144%
Kings River, below Pine Flat Reservoir average = 1224
90% Exceedance 830 68% 870 71% 830 68% 830 68%
50% Exceedance 1230 101% 1240 101% 1170 96% 1140 93%
10% Exceedance 2030 166% 1980 162% 1860 152% 1780 145%
Kaweah River, below Terminus Reservoir average = 286
90% Exceedance 180 63% 200 70% 190 66% 190 66%
50% Exceedance 280 98% 290 101% 270 94% 260 91%
10% Exceedance 500 175% 490 171% 460 161% 440 154%
Tule River, below Lake Success average = 64
90% Exceedance 28 44% 33 52% 32 50% 34 54%
50% Exceedance 54 85% 57 90% 54 85% 54 85%
10% Exceedance 135 213% 134 211% 129 203% 128 202%
Kern River, inflow to Isabella Lake average = 461
90% Exceedance 270 59% 290 63% 280 61% 280 61%
50% Exceedance 430 93% 440 95% 420 91% 410 89%
10% Exceedance 910 197% 870 189% 800 173% 750 163%
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.
