B120UP.200704 (04/26/07 1146)
DEPARTMENT OF WATER RESOURCES
California Cooperative Snow Surveys
WATER SUPPLY FORECAST UPDATE
2007 April-July Unimpaired Runoff (1,000 Acre-feet)
Apr 1 %Avg Apr 10 %Avg Apr 17 %Avg Apr 24 %Avg
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Shasta Lake, total inflow average = 1819
90% Exceedence 860 47% 840 46% 860 47% 960 53%
50% Exceedence 1210 67% 1160 64% 1150 63% 1220 67%
10% Exceedence 1850 102% 1670 92% 1580 87% 1570 86%
Feather River at Oroville average = 1782
90% Exceedence 510 29% 480 27% 500 28% 560 31%
50% Exceedence 700 39% 640 36% 650 36% 700 39%
10% Exceedence 1270 71% 1110 62% 1050 59% 1030 58%
Yuba River near Smartville average = 1006
90% Exceedence 340 34% 320 32% 350 35% 400 40%
50% Exceedence 470 47% 430 43% 450 45% 500 50%
10% Exceedence 770 77% 670 67% 650 65% 650 65%
American River, below Folsom Lake average = 1240
90% Exceedence 430 35% 400 32% 420 34% 470 38%
50% Exceedence 590 48% 540 44% 550 44% 590 48%
10% Exceedence 940 76% 800 65% 760 61% 750 60%
Mokelumne River, inflow to Pardee Reservoir average = 461
90% Exceedence 170 37% 155 34% 160 35% 190 41%
50% Exceedence 230 50% 210 46% 210 46% 230 50%
10% Exceedence 350 76% 320 69% 310 67% 300 65%
Stanislaus River, below Goodwin Res. (blw New Melones) average = 702
90% Exceedence 220 31% 200 28% 210 30% 230 33%
50% Exceedence 310 44% 280 40% 290 41% 310 44%
10% Exceedence 500 71% 440 63% 430 61% 430 61%
Tuolumne River, below La Grange Res. (blw Don Pedro) average = 1220
90% Exceedence 450 37% 400 33% 430 35% 480 39%
50% Exceedence 630 52% 570 47% 580 48% 610 50%
10% Exceedence 910 75% 820 67% 800 66% 790 65%
Merced River, below Merced Falls (below Lake McClure) average = 632
90% Exceedence 200 32% 190 30% 200 32% 220 35%
50% Exceedence 260 41% 240 38% 250 40% 260 41%
10% Exceedence 430 68% 380 60% 370 59% 350 55%
San Joaquin River, below Millerton Lake average = 1254
90% Exceedence 360 29% 340 27% 350 28% 390 31%
50% Exceedence 530 42% 490 39% 490 39% 510 41%
10% Exceedence 790 63% 720 57% 690 55% 680 54%
Kings River, below Pine Flat Reservoir average = 1224
90% Exceedence 350 29% 320 26% 330 27% 380 31%
50% Exceedence 510 42% 470 38% 460 38% 500 41%
10% Exceedence 750 61% 680 56% 640 52% 630 51%
Kaweah River, below Terminus Reservoir average = 286
90% Exceedence 80 28% 75 26% 75 26% 85 30%
50% Exceedence 100 35% 95 33% 95 33% 100 35%
10% Exceedence 180 63% 160 56% 155 54% 150 52%
Tule River, below Lake Success average = 64
90% Exceedence 13 20% 12 19% 14 22% 17 27%
50% Exceedence 20 31% 18 28% 20 31% 22 35%
10% Exceedence 41 65% 34 54% 35 55% 36 57%
Kern River, inflow to Isabella Lake average = 461
90% Exceedence 100 22% 95 21% 110 24% 125 27%
50% Exceedence 150 33% 140 30% 150 33% 160 35%
10% Exceedence 250 54% 230 50% 220 48% 210 46%
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) 574-2617 (e-mail daver@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 exceedence levels are derived from historical data.
The 90 percent exceedence level and the 10 percent exceedence 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.