B120UP.201005 (05/27/10 1340)
DEPARTMENT OF WATER RESOURCES
California Cooperative Snow Surveys
WATER SUPPLY FORECAST UPDATE
2010 April-July Unimpaired Runoff (1,000 Acre-feet)
May 1 %Avg May 11 %Avg May 18 %Avg May 25 %Avg
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Shasta Lake, Total Inflow average = 1819
90% Exceedance 1840 101% 1860 102% 1840 101% 1870 103%
50% Exceedance 2070 114% 2070 114% 2040 112% 2050 113%
10% Exceedance 2470 136% 2410 132% 2340 129% 2310 127%
Sacramento River, above Bend Bridge (near Red Bluff) average = 2494
90% Exceedance 2540 102% 2580 103% 2560 103% 2590 104%
50% Exceedance 2850 114% 2860 115% 2820 113% 2840 114%
10% Exceedance 3380 136% 3320 133% 3230 129% 3200 128%
Feather River at Oroville average = 1782
90% Exceedance 1620 91% 1710 96% 1710 96% 1780 100%
50% Exceedance 1890 106% 1950 109% 1930 108% 1970 111%
10% Exceedance 2300 129% 2290 129% 2220 125% 2220 125%
Yuba River near Smartsville average = 1006
90% Exceedance 1030 102% 1080 107% 1090 108% 1120 111%
50% Exceedance 1180 117% 1200 119% 1190 118% 1210 120%
10% Exceedance 1330 132% 1330 132% 1310 130% 1310 130%
American River, below Folsom Lake average = 1240
90% Exceedance 1190 96% 1270 102% 1300 105% 1340 108%
50% Exceedance 1360 110% 1410 114% 1420 115% 1440 116%
10% Exceedance 1560 126% 1570 127% 1560 126% 1550 125%
Mokelumne River, Inflow to Pardee Reservoir average = 461
90% Exceedance 450 98% 460 100% 470 102% 470 102%
50% Exceedance 480 104% 490 106% 500 108% 500 108%
10% Exceedance 530 115% 540 117% 540 117% 540 117%
Stanislaus River, below Goodwin Res. (blw New Melones) average = 702
90% Exceedance 680 97% 710 101% 750 107% 760 108%
50% Exceedance 770 110% 790 113% 810 115% 810 115%
10% Exceedance 870 124% 870 124% 880 125% 870 124%
Tuolumne River, below La Grange Res. (blw Don Pedro) average = 1220
90% Exceedance 1280 105% 1320 108% 1350 111% 1350 111%
50% Exceedance 1380 113% 1410 116% 1430 117% 1420 116%
10% Exceedance 1550 127% 1550 127% 1560 128% 1540 126%
Merced River, below Merced Falls (blw Lake McClure) average = 632
90% Exceedance 710 112% 730 115% 750 119% 740 117%
50% Exceedance 770 122% 780 123% 790 125% 780 123%
10% Exceedance 880 139% 870 138% 860 136% 840 133%
San Joaquin River, below Millerton Lake average = 1254
90% Exceedance 1510 120% 1510 120% 1520 121% 1520 121%
50% Exceedance 1660 132% 1630 130% 1630 130% 1610 128%
10% Exceedance 1830 146% 1760 140% 1740 139% 1690 135%
Kings River, below Pine Flat Reservoir average = 1224
90% Exceedance 1370 112% 1380 113% 1390 114% 1400 114%
50% Exceedance 1470 120% 1470 120% 1470 120% 1480 121%
10% Exceedance 1590 130% 1570 128% 1560 127% 1560 127%
Kaweah River, below Terminus Reservoir average = 286
90% Exceedance 350 122% 360 126% 360 126% 360 126%
50% Exceedance 380 133% 390 136% 380 133% 380 133%
10% Exceedance 440 154% 440 154% 420 147% 410 143%
Tule River, below Lake Success average = 64
90% Exceedance 79 124% 79 124% 80 126% 79 124%
50% Exceedance 85 134% 85 134% 85 134% 84 132%
10% Exceedance 107 168% 103 162% 100 157% 96 151%
Kern River, inflow to Isabella Lake average = 461
90% Exceedance 500 108% 490 106% 500 108% 490 106%
50% Exceedance 540 117% 530 115% 530 115% 520 113%
10% Exceedance 610 132% 590 128% 580 126% 560 121%
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.
