B120 (05/08/15 1235)

Department of Water Resources California Cooperative Snow Surveys May 1, 2015 FORECAST OF UNIMPAIRED RUNOFF (in thousands of acre-feet) April-July Forecast April Percent 80% thru of Probability July Average Range -------------------------------------------------------------------------------- NORTH COAST Trinity River at Lewiston Lake 110 17% 85 - 200 Scott River near Fort Jones 21 12% SACRAMENTO RIVER Sacramento River above Shasta Lake 65 22% McCloud River above Shasta Lake 160 41% Pit River above Shasta Lake 460 44% Total inflow to Shasta Lake 710 39% 600 - 860 Sacramento River above Bend Bridge 970 39% 800 - 1140 Feather River at Oroville 340 19% 270 - 500 Yuba River at Smartsville 165 17% 130 - 230 American River below Folsom Lake 175 14% 145 - 250 SAN JOAQUIN RIVER Cosumnes River at Michigan Bar 10 8% 7 - 20 Mokelumne River inflow to Pardee 75 16% 60 - 100 Stanislaus River below Goodwin Res. 95 14% 70 - 160 Tuolumne River below La Grange 240 20% 190 - 300 Merced River below Merced Falls 85 13% 65 - 140 San Joaquin River inflow to Millerton Lk 130 10% 105 - 210 TULARE LAKE Kings River below Pine Flat Res. 135 11% 110 - 210 Kaweah River below Terminus Res. 38 13% 30 - 55 Tule River below Lake Success 2 3% 1 - 11 Kern River inflow to Lake Isabella 45 10% 35 - 90 NORTH LAHONTAN Truckee River,Tahoe to Farad accretions 40 16% Lake Tahoe Rise, in feet 0.1 7% West Carson River at Woodfords 7 13% East Carson River near Gardnerville 35 19% West Walker River below Little Walker 30 19% East Walker River near Bridgeport 5 8% Water-Year (WY) Forecast and Monthly Distribution Oct Water 80% WY thru Feb Mar Apr May Jun Jul Aug Sep Year Probability % Jan Range Avg -------------------------------------------------------------------------------- Trinity, Lewiston 418 294 67 56 38 14 2 0 0 889 864 - 985 65 Inflow to Shasta 1621 720 273 219 180 161 150 140 136 3600 3435 - 3810 60 Sacramento, Bend 2652 1068 348 306 265 221 178 155 162 5355 5120 - 5610 61 Feather, Oroville 916 442 157 121 100 60 59 55 50 1960 1850 - 2140 43 Yuba, Smartville 398 204 102 67 75 17 6 0 0 869 835 - 950 37 American, Folsom 332 242 86 80 80 15 0 0 0 835 805 - 910 31 Cosumnes, Mich.Bar 22 38 9 7 3 0 0 0 0 79 76 - 90 21 Mokelumne, Pardee 43 65 30 30 42 3 0 0 0 213 198 - 245 28 Stanislaus, Gdw. 64 92 37 37 47 11 0 0 0 288 263 - 360 25 Tuolumne, LaGrange 106 114 57 85 120 25 10 0 0 517 467 - 585 27 Merced, McClure 22 25 19 30 39 12 4 0 0 151 131 - 210 15 San Joaquin, Mil. 47 43 34 39 52 26 13 8 3 265 237 - 355 14 Kings, Pine Flat 49 46 42 46 57 22 10 4 4 280 254 - 365 16 Kaweah, Terminus 15 17 13 10 20 6 2 1 1 85 76 - 110 19 Tule, Success 4 3 1 1 1 0 0 0 0 10 9 - 20 7 Kern, Isabella 36 15 13 14 13 11 7 6 5 120 106 - 175 16 Notes: 50 year averages are based on years 1961 to 2010. Unimpaired runoff represents the natural water production of a river basin, unaltered by upsteam diversions, storage, or by export or import of water to or from other watersheds. Groundwater changes due to human activity or not considered. Forecasted runoff assumes median conditions subsequent to the date of forecast. Runoff probability ranges are statistically derived from historical data. The 80% probability range is comprised of the 90% exceedance level value and the 10% exceedance level value. The actual runoff should fall within the stated limits eight times out of ten. Forecast point names are based on USGS gage names. For more information please contact: John King (916) 574-2637 John.J.King@water.ca.gov Steve Nemeth (916) 574-2634 Stephen.Nemeth@water.ca.gov Dave Rizzardo (916) 574-2983 David.Rizzardo@water.ca.gov Andy Reising (916) 574-2181 Andrew.Reising@water.ca.gov Sean de Guzman (916) 574-2208 Sean.deGuzman@water.ca.gov