B120UP.200705 (05/31/07 1408)
DEPARTMENT OF WATER RESOURCES
California Cooperative Snow Surveys
WATER SUPPLY FORECAST UPDATE
2007 April-July Unimpaired Runoff (1,000 Acre-feet)
May 1 %Avg May 15 %Avg May 22 %Avg May 29 %Avg
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Shasta Lake, total inflow average = 1819
90% Exceedence 900 49% 910 50% 930 51% 930 51%
50% Exceedence 1120 62% 1090 60% 1050 58% 1030 57%
10% Exceedence 1420 78% 1360 75% 1200 66% 1160 64%
Feather River at Oroville average = 1782
90% Exceedence 570 32% 610 34% 610 34% 610 34%
50% Exceedence 670 38% 700 39% 690 39% 690 39%
10% Exceedence 920 52% 910 51% 850 48% 820 46%
Yuba River near Smartville average = 1006
90% Exceedence 360 36% 390 39% 380 38% 370 37%
50% Exceedence 450 45% 470 47% 460 46% 440 44%
10% Exceedence 580 58% 570 57% 550 55% 520 52%
American River, below Folsom Lake average = 1240
90% Exceedence 430 35% 460 37% 480 39% 480 39%
50% Exceedence 530 43% 550 44% 540 44% 540 44%
10% Exceedence 670 54% 660 53% 620 50% 600 48%
Mokelumne River, inflow to Pardee Reservoir average = 461
90% Exceedence 160 35% 180 39% 190 41% 185 40%
50% Exceedence 200 43% 210 46% 205 44% 200 43%
10% Exceedence 270 59% 260 56% 250 54% 230 50%
Stanislaus River, below Goodwin Res. (blw New Melones) average = 702
90% Exceedence 230 33% 250 36% 270 38% 270 38%
50% Exceedence 290 41% 300 43% 295 42% 290 41%
10% Exceedence 400 57% 390 56% 370 53% 360 51%
Tuolumne River, below La Grange Res. (blw Don Pedro) average = 1220
90% Exceedence 440 36% 480 39% 480 39% 470 39%
50% Exceedence 560 46% 580 48% 570 47% 560 46%
10% Exceedence 710 58% 700 57% 680 56% 660 54%
Merced River, below Merced Falls (below Lake McClure) average = 632
90% Exceedence 180 28% 190 30% 205 32% 195 31%
50% Exceedence 230 36% 230 36% 225 36% 220 35%
10% Exceedence 320 51% 310 49% 300 47% 290 46%
San Joaquin River, below Millerton Lake average = 1254
90% Exceedence 390 31% 400 32% 400 32% 390 31%
50% Exceedence 490 39% 470 37% 460 37% 450 36%
10% Exceedence 640 51% 600 48% 580 46% 560 45%
Kings River, below Pine Flat Reservoir average = 1224
90% Exceedence 380 31% 390 32% 410 34% 400 33%
50% Exceedence 480 39% 480 39% 470 38% 460 38%
10% Exceedence 580 47% 570 47% 560 46% 550 45%
Kaweah River, below Terminus Reservoir average = 286
90% Exceedence 75 26% 76 27% 86 30% 86 30%
50% Exceedence 95 33% 94 33% 95 33% 94 33%
10% Exceedence 135 47% 125 44% 120 42% 115 40%
Tule River, below Lake Success average = 64
90% Exceedence 14 22% 12 19% 12 19% 12 19%
50% Exceedence 19 30% 16 25% 15 24% 14 22%
10% Exceedence 32 50% 26 41% 22 35% 20 31%
Kern River, inflow to Isabella Lake average = 461
90% Exceedence 115 25% 115 25% 110 24% 110 24%
50% Exceedence 145 31% 140 30% 135 29% 133 29%
10% Exceedence 200 43% 190 41% 175 38% 165 36%
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.