B120UP.201003 (03/25/10 0920)
DEPARTMENT OF WATER RESOURCES
California Cooperative Snow Surveys
WATER SUPPLY FORECAST UPDATE
2010 April-July Unimpaired Runoff (1,000 Acre-feet)
Mar 1 %Avg Mar 9 %Avg Mar 16 %Avg Mar 23 %Avg
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Shasta Lake, Total Inflow average = 1819
90% Exceedance 1240 68% 1310 72% 1350 74% 1290 71%
50% Exceedance 1680 92% 1730 95% 1750 96% 1670 92%
10% Exceedance 2580 142% 2600 143% 2600 143% 2500 137%
Sacramento River, above Bend Bridge (near Red Bluff) average = 2494
90% Exceedance 1540 62% 1650 66% 1690 68% 1610 65%
50% Exceedance 2170 87% 2250 90% 2270 91% 2160 87%
10% Exceedance 3600 144% 3610 145% 3570 143% 3410 137%
Feather River at Oroville average = 1782
90% Exceedance 800 45% 920 52% 1020 57% 990 56%
50% Exceedance 1400 79% 1460 82% 1510 85% 1430 80%
10% Exceedance 2590 145% 2550 143% 2520 141% 2370 133%
Yuba River near Smartsville average = 1006
90% Exceedance 510 51% 560 56% 590 59% 570 57%
50% Exceedance 870 87% 900 89% 910 90% 870 87%
10% Exceedance 1440 143% 1430 142% 1400 139% 1320 131%
American River, below Folsom Lake average = 1240
90% Exceedance 560 45% 640 52% 710 57% 690 56%
50% Exceedance 1010 81% 1050 85% 1080 87% 1020 82%
10% Exceedance 1840 148% 1830 148% 1820 147% 1720 139%
Mokelumne River, Inflow to Pardee Reservoir average = 461
90% Exceedance 290 63% 310 67% 330 72% 320 69%
50% Exceedance 410 89% 420 91% 430 93% 410 89%
10% Exceedance 650 141% 640 139% 630 137% 590 128%
Stanislaus River, below Goodwin Res. (blw New Melones) average = 702
90% Exceedance 460 66% 490 70% 510 73% 500 71%
50% Exceedance 630 90% 650 93% 660 94% 640 91%
10% Exceedance 1020 145% 1000 142% 980 140% 930 132%
Tuolumne River, below La Grange Res. (blw Don Pedro) average = 1220
90% Exceedance 910 75% 960 79% 1000 82% 960 79%
50% Exceedance 1170 96% 1200 98% 1220 100% 1160 95%
10% Exceedance 1790 147% 1760 144% 1730 142% 1620 133%
Merced River, below Merced Falls (blw Lake McClure) average = 632
90% Exceedance 500 79% 530 84% 550 87% 530 84%
50% Exceedance 640 101% 660 104% 670 106% 640 101%
10% Exceedance 990 157% 980 155% 970 153% 910 144%
San Joaquin River, below Millerton Lake average = 1254
90% Exceedance 1050 84% 1100 88% 1140 91% 1110 89%
50% Exceedance 1330 106% 1360 108% 1380 110% 1330 106%
10% Exceedance 1920 153% 1890 151% 1850 148% 1740 139%
Kings River, below Pine Flat Reservoir average = 1224
90% Exceedance 1070 87% 1140 93% 1180 96% 1160 95%
50% Exceedance 1350 110% 1390 114% 1400 114% 1350 110%
10% Exceedance 1940 159% 1910 156% 1850 151% 1730 141%
Kaweah River, below Terminus Reservoir average = 286
90% Exceedance 240 84% 260 91% 270 94% 260 91%
50% Exceedance 310 108% 330 115% 330 115% 320 112%
10% Exceedance 480 168% 480 168% 470 164% 450 157%
Tule River, below Lake Success average = 64
90% Exceedance 42 66% 47 74% 50 79% 48 76%
50% Exceedance 61 96% 65 102% 67 105% 63 99%
10% Exceedance 134 211% 132 208% 129 203% 120 189%
Kern River, inflow to Isabella Lake average = 461
90% Exceedance 350 76% 390 85% 400 87% 390 85%
50% Exceedance 470 102% 500 108% 500 108% 480 104%
10% Exceedance 770 167% 750 163% 710 154% 650 141%
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.
