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Home My WebLink AboutWater Conditions in CA - Report 2 z x u a. M� 4� w u " y�5y u Y � u N " r � y u � m M« � yl� MMMM �� STATE OF CALIFORNIA Edmund G. Brown, Jr., Governor CALIFORNIA NATURAL RESOURCES AGENCY John Laird, Secretary for Natural Resources Department of Water Resources Karla Nemeth Director Cindy Messer Erich Koch Taryn Ravazzini Katherine S. Kishaba Chief Deputy Director Deputy Director Deputy Director Deputy Director Joel Ledesma Christy Jones Spencer Kenner Deputy Director Deputy Director Chief Counsel Division of Flood Management Jon Ericson..............................................................................Chief, Division of Flood Management MauryRoos..............................................................................................................State Hydrologist Vacant...................................................................................Chief, Hydrology and Flood Operations Sudhakar Talanki.........................................................................................Chief, Hydrology Branch Prepared by Frank Gehrke...........................................................................................Chief, Coop Snow Surveys Dave Rizzardo..................................................................................................Chief, Snow Surveys Sean DeGuzman........................................................................................................Engineer, W.R. StephenNemeth.........................................................................................................Engineer, W.R. JohnKing....................................................................................................................Engineer, W.R. AndrewReising...........................................................................................................Engineer, W.R. Ashok.Bathulla............................................................................................................Engineer, W.R. Matt Winston............................................................................................Senior Meteorologist, W.R. COOPERATING AGENCIES Public Agencies State Water Project Contractors Buena Vista Water Storage District Municipalities East Bay Municipal Utility District City of Bakersfield Water Department Eldorado Irrigation District City of Los Angeles Department of Water and Power Friant Water Users Association City and County of San Francisco Hetch Hetchy Water and Power Kaweah Delta Water Conservation District State Agencies Kern Delta Water District University of California Kings River Conservation District Central Sierra Snow Laboratory Lower Tule River Irrigation District Scripps Institution of Oceanography Merced Irrigation District California Department of Forestry&Fire Protection Modesto Irrigation District California Department of water Resources Nevada Irrigation District Public Utilities North Kern Water Storage District Pacific Gas and Electric Company Northern California Power Agency Southern California Edison Company Oakdale Irrigation District Federal Agencies Omochumne-Hartnell Water District U.S.Department of Agriculture Placer County Water Agency Forest Service(14 National Forests) Sacramento Municipal Utility Disirict Natural Resource Conservation Service San Joaquin River Exchange Contractors Water Authority U.S.Department of Commerce South Feather Water and Power Agency National Weather Service South San Joaquin Irrigation District U.S.Department of Interior Tri-Dam Project Bureau of Reclamation Truckee River Basin Water Commission Geological Survey,Water Resources Tulare Lake Basin Water Storage District National Park Service(3 National Parks) Turlock Irrigation District U.S.Department of Army Yuba County,water Agency. Corps of Engineers_ Private Organizations National Aeronautics and Space Administration J.G.Boswell Company Jet Propulsion Laboratory Kaweah and St.Johns River Association Other Cooperative Programs Kings River Water Association Nevada Cooperative Snow Surveys Tule River Association Oregon Cooperative Snow Surveys Summary of Water Conditions March 1, 2018 February was almost totally dry, eased only slightly on the last day by the beginnings of a major snowstorm in early March which boosted the snowpack to about one fifth normal. The outlook is not much better than the drought conditions a couple of years ago, except that carryover reservoir storage from the exceedingly wet 2017 will ease the deficit some this year. About one third of the precipitation season is left, so chances of recovery to normal are slim. Forecasts of median April through July runoff are expected to be only 40 percent of average compared to last year's 180 percent at this time and an eventual 190 percent. The water year forecast this year is only about 50 percent, compared to an actual 220 percent for 2017. Snowpack water content is about 20 percent of average for this date and only a bit over 15 percent of the April 1 average, the normal peak of the accumulation season. Percentages are a little higher on the east side of the Sierra than the western side. Last year the pack was 185 percent of average. Precipitation from October through February was 50 percent of average statewide compared to 190 percent last year. The range is from around 60 percent in the north to 25-30 percent in the south. Runoff to date has been about 45 percent statewide with higher amounts from the higher elevation Sierra rivers, partly a residual from last year. Estimated February runoff was only 25 percent of average. Estimated runoff of the eight major rivers of the Sacramento-San Joaquin River region in February was 0.8 million acre-feet. Reservoir storage is about 100 percent of average compared to 120 percent last year at this time. SUMMARY OF WATER CONDITIONS IN PERCENT OF AVERAGE PRECIPITATION MARCH 1 MARCH 1 RUNOFF APRIL-JULY WATER YEAR HYDROLOGIC REGION OCTOBER 1 SNOW WATER RESERVOIR OCTOBER 7 RUNOFF RUNOFF TO DATE CONTENT STORAGE TO DATE FORECAST FORECAST NORTH COAST 60 20 95 35 30 35 SAN FRANCISCO BAY 50 -- 75 10 -- -- CENTRAL COAST 35 -- 60 5 -- -- SOUTH COAST 25 -- 85 5 -- - SACRAMENTO RIVER 60 15 95 50 50 55 SAN JOAQUIN RIVER 45 15 110 50 35 45 TULARE LAKE 30 15 100 50 30 35 NORTH LAHONTAN 65 20 165 120 40 55 SOUTH LAHONTAN 30 30 105 110 55 60 COLORADO RIVER 30 -- -- -- -- - STATEWIDE 50 15 100 45 40 50 1 DEPARMENT OF WATER RESOURCES CALIFORNIA COOPERATIVE SNOW SURVEYS SEASONAL PRECIPITATION IN PERCENT OF AVERAGE TO DATE October 1, 2017 through February 28, 2018 RIVER a N NC glt't.R pt1' NL 60%k - SR 65% °60% SF ry4 J`, gt�Cr y..q rLIC)L vi.N4 50% ' FI4'IiR "L45% RIV[,71 e;Lri. S TL 0% SL r 30% CCF. Hydrologic Regions 35% Al RtF.I 1: NC - North Coast ``` SF - San Francisco Bay �ACR CC - Central Coast SC xt SC - South Coast ?�r 'Fy. 30% SR - Sacramento River 25% SJ - San Joaquin TL -Tulare Lake NL - North Lahontan s� {i1ril 4� t SL - South Lahontan CR - Colorado River-Desert WATER YEAR 1S OCTOBER 1 THROUGH SEPTEMBER 30 2 DEPARMENT OF WATER RESOURCES CALIFORNIA COOPERATIVE SNOW SURVEYS FORECAST OF APRIL-JULY UNIMPAIRED SNOWMELT RUNOFF March 1, 2018 Label 100%- Runoff forecast in percent of normal N SCOTT 3 % UPPER SACRAMENTO 72% TRINITY 00 l Rid f; FEATHER 36% TRUCKEE 32% YUBA 41% r cV ref TAHOE 52% AMERICAN 8% '. 1 CARSON 45% COSUMNES -- �° -� WALKER 43% MOKELUMNE 3 MONO* 64% STANISLAUS 3a r' `' OWENS* 51% TUOLUMNE 41.% MERGED 32% SAN JOAQUIN 3 R11F•R � KINGS 31% 5 KAWEAH 23% TOLE 19% KERN 38% t 10 r * FORECAST BY DEPARTMENT OF WATER AND POWER, CITY OF LOS ANGELES 3 March 1, 2018 FORECASTS APRIL-JULY UNIMPAIRED RUNOFF Apr-Jul Unimpaired,Runoff in 1,000 Acre-Feet(1) HYDROLOGIC REGION HISTORICALFORECAST and watershed 50 Yr i Max of Min of Apr Jul Pct 80% Avg € Record € Record of Probability 2 10 10 Forecast Avg Range 1 North Coast Trinity River at Lewiston Lake 639 1.,593 80 190 30% 120 - 280 SACRAMENTO RIVER Upper Sacramento River Sacramento River at Delta above Shasta Lake 295 751 39 125 42% McCloud River above Shasta Lake 385 850 1.85 300 78% Pit River near Montgomery Creek+Squaw Creek 1,020 2,098 480 800 78% Total Inflow to Shasta Lake 1,756 3,525 711 1,250 71% 940 -1,510 Sacramento River above Bend Bridge,near Red Bluff 2,421. 5,117 943 1,530 63% 1,130 -1,870 Feather River Feather River at Lake Almanor near Prattville(3) 333 675 120 150 45% North Fork at Pulga(3) 1,028 2,41.6 243 360 35% Middle Fork near Clio(4) 86 518 4 30 35% South Fork at Ponderosa Dam(3) 110 267 13 35 32% Feather River at Oroville 1,704 4,676 378 610 360/D 390 810 Yuba River North Yuba below Goodyears Bar 279 647 51 115 41% Inflow to Jackson Mdws and Bowman Reservoirs(3) 112 236 25 45 40% South Yuba at Langs Crossing(3) 233 481 57 100 43% Yuba River near Smartsville plus Deer Creek 968 2,424 151 400 41% 260 520 American River North Fork at North Fork Dam(3) 262 716 43 100 38% Middle Fork near Auburn(3) 522 1,406 100 200 38% Silver Creek below Camino Diversion Dam(3) 173 386 37 70 40% American River below Folsom Lake 1.,199 3,074 185 450 38% 290 600 SAN JOAQUIN RIVER Cosumnes River at Michigan Sar 125 446 8 35 28% 20 65 Mokelumne River North Fork near West Point(5) 437 829 1.04 160 37% Total Inflow to Pardee Reservoir 457 1,076 75 170 37% 120 250 Stanislaus River Middle Fork below Beardsley Dam(3) 334 702 64 120 36% North Fork Inflow to McKays Point Dam(3) 224 503 34 79 35% Stanislaus River below Goodwin Reservoir(9) 682 1,710 116 240 35% 180 - 360 Tuolumne River Cherry Creek&Eleanor Creek near Hetch Hetchy 31.5 727 97 130 41% Tuolumne River near Hetch Hetchy 604 1,392 153 260 43% Tuolumne River below LaGrange Reservoir(9) 1,193 2,682 301 490 41% 350 640 Merced River Merced River at Pohono Bridge 372 888 80 120 32% Merced River below Merced Falls(9) 623 1,588 104 200 32% 140 260 San Joaquin River San Joaquin River at Mammoth Pool(7) 1,026 2,279 235 390 38% Big Creek below Huntington Lake(8) 91 264 11 30 33% South Fork near Florence Lake(7) 201 511 58 90 45% San Joaquin River inflow to Millerton Lake 1,228 3,355 193 450 37% 320 - 570 TULARE LAKE Kings River North Fork Kings River near Cliff Camp(3) 239 565 50 70 29% Kings River below Pine Flat Reservoir 1,210 3,113 208 370 31% 240 - 490 Kaweah River below Terminus Reservoir 285 814 42 65 23% 40 - 90 Tule River below Lake Success 63 259 1 12 19% 6 19 Kern River Kern River near Kernville 384 1,203 83 150 39% Kern River inflowto Lake Isabella 458 1,657 57 175 38% 115 245 (1)See inside the back cover for definition. (5)36 year average based on years 1936-72. (2)All 50 year averages are based on years 1966-2015 unless (6)45 year average based on years 1936-81. otherwise noted. (7)50 year average based on years 1953-2002. (3)50 year average based on years 1.941-90. (8)50 year average based on years 1.946-1.995. (4)44 year average based on years 1936-79. 4 March 1, 2018 FORECASTS WATER YEAR UNIMPAIRED RUNOFF Water Year Unimpaired Runoff in 1,000 Acre-Feet(1) HISTORICAL DISTRIBUTION FORECAST 50 Yr Max of Min of Oct Water Pct 80% Avg Record € Record Thru € Feb Mar Apr May Jun Jul Aug Sep Year of Probability 210 10 Jan € Forecast € AvgRange 1 1,348 2,990 200 135 43 76 85 75 27 3 1 0 445 33% 345 575 860 1,966 165 105 27 70 55 40 20 10 7 7 340 40% - - 1,183 2,353 557 326 69 90 100 80 65 55 51 50 885 75% 3,002 5,150 1,484 716 183 225 260 220 175 145 125 126 2,175 72% - - 5,831 10,796 2,479 1,156 254 600 460 355 240 195 178 177 3,615 62% 3,065 4,075 8,544 17,180 3,294 1,582 325 800 550 430 305 245 205 208 4,650 54% 3,930 5,260 780 1,269 366 2,417 4,400 666 219 637 24 291 562 32 4,407 10,178 995 843 181 440 260 170 100 80 66 56 2,195 50% 1,770 - 2,580 564 1,056 102 181 292 30 379 565 98 2,268 5,604 369 488 88 272 190 155 40 15 8 9 1,265 56% 1,020 - 1,475 616 1,234 66 1,070 2,575 144 318 705 59 2,626 7,391 349 502 98 299 215 180 50 5 0 1 1,350 51% 1,080 1,605 379 1,253 20 43 9 38 20 11 3 1 0 0 125 33% 90 - 190 626 1,009 197 748 1,901 129 106 18 60 70 80 18 2 1 0 355 47% 285 - 465 471 929 88 1,149 3,078 155 154 29 87 100 100 35 5 1 0 510 44% 425 - 675 461 1,147 123 770 1,661 258 1,909 4,631 383 229 34 142 165 220 90 15 3 1 900 47% 715 - 1,095 461 1,020 92 992 2,787 150 73 16 67 75 95 25 5 0 0 355 36% 275 - 440 1,337 2,964 308 112 298 14 248 653 71 1,793 4,642 327 130 27 98 125 200 95 30 13 6 725 40% 560 - 880 284 607 58 1,702 4,287 359 116 23 73 100 175 70 25 10 7 600 35% 435 - 750 451 1,402 89 28 7 23 24 30 9 2 1 1 125 28% 90 - 160 147 615 10 13 3 8 7 4 1 0 0 0 36 24% 25 - 50 558 1,577 163 728 2,318 130 103 18 26 45 65 45 20 10 8 340 47% 265 - 430 (9)Forecast paint names based on USGS gage names. Stanislaus below Goodwin also known as inflow to New Melones,Tuolumne River below La Grange also known as inflow to Don Pedro,Merced River below Merced Falls also known as inflow to McClure. (10)For the tributaries,the period of record over which the minimum and maximum values are found does not include years after water year 2011. *Unimpaired runoff in months prior to forecast date are based on measured flows. 5 March 1, 2018 FORECASTS APRIL-JULY UNIMPAIRED RUNOFF Apr-Jul Unimpaired Runoff in 1,000 Acre-Feet(1) HYDROLOGIC REGION HISTORICAL FORECAST and Watershed 50 Yr Max of Min of Pct Apr Jul Avg € Record € Record € of 2 6 6 Forecast Avg NORTH COAST Scott River Scott River nr Ft Jones(3) 173 398 22 67 39% Klamath River Total inflow to Upper Klamath Lake(4) 475 1,150 149 298 63% NORTH LAHONTAN Truckee River Lake Tahoe to Farad accretions 250 713 48 80 32% Lake Tahoe Rise(assuming gates closed,ft) 1.3 5.4 0.2 0.7 52% Carson River West Fork Carson River at Woodfords 52 135 10 27 52% East Fork Carson River near Gardnerville 182 480 43 82 45% Walker River West Walker River below Little Walker, near Coleville 153 410 35 68 44% East Walker River near Bridgeport 61 209 7 24 39% SOUTH LAHONTAN Owens River Total tributary flow to Owens River(5) 231 579 84 119 51% (1)See inside the back cover for definition. (2)All 50 year averages are based on years 1966-2015 unless otherwise noted. (3)Forecast by National Weather Service California-Nevada River Forecast Center. 30 yr average(1981-2010). (4)Forecast by U.S.Natural Resources Conservation Service and National Weather Service California-Nevada River Forecast Center,April through September forecast,30 year average based on years 1981-2010. (5)Forecast by Department of Water and Power,City of Los Angeles,average based on years 1961-2010. (6)For the tributaries,the period of record over which the minimum values are found does not include years after water year 2011. 6 NORTH COAST REGION Snowpack Accumulation SNOWPACK f=irst of the month measurements made at 10 snow courses indicate an area wide snow water Water Content in % of April 1 Average equivalent of 4.5 inches.This is 20 percent of the 250 seasonal April 1 average and 20 percent of the March 1 225 average. Last year this time the pack was holding 200 175 34.3 inches of water. 150 125 100 75 - 50 25 - Jan 1 Feb 1 Mar 1 Apr 1 May 1 Precipitation PRECIPITATION Seasonal precipitation (October 1 October 1 to date in % of average through to the end of February) on this area was 60 percent 20 _._. _....._ . _......... .......... .. ....__. ...._... of normal. Precipitation last month was about 25 percent of 17 - - -- - - - - - the monthly average. Season precipitation at this time last 1 year stood at 165 percent of normal. 10 75- 50-- 25-- 0__ 5 ..2 - - Smith Klamath Trinity Eel Russian ®WY 2017 _WY 2018 Reservoir Storage RESERVOIR STORAGEFirst of the month storage at Contents of major reservoirs in %of capacity 6 reservoirs was 2.12 million acre-feet which is 95 percent of 100--_ __.- _ _-__.__._. .___._ _.__._ ._...__ _ _._._.__ ...._... _._ average. About 70 percent of available capacity was being e used. Storage in these reservoirs at this time last year was 110 percent of average. 60- 40- 20-- 42 - - - Klamath Trinity Eel Russian E=WY 2017 -WY 2018 10 Yr Avg Runoff RUNOFF Seasonal runoff of streams draining this area October 1 to date in %of average totaled 2.53 million acre-feet which is 35 percent of average. 30 - - - " -- - - ""_ - - - - - - -- Last year, runoff for the same period was 220 percent of 25 -------------- -------------- --- average. 200--7 ---- --- - - ----- -- -- 15 - -_ _ 100- 50- MEL, 4 . . Klamath,Copco Trinity Eel Russian to Orleans ®WY 2017 _WY 2018 7 SACRAMENTO RIVER REGION Snowpack Accumulation SNOWPACK First of the month measurements made at Water Content in % of April I Average 68 snow courses indicate an area wide snow water equivalent of 4.8 inches. This is 15 percent of the 225 seasonal April 1 average and 20 percent of the March 1 zs zoo - - average. Last year this time the pack was holding 175 41.1 inches of water. 150 125 100 _-... 75 50 25 0 Jan 1 Feb i Mar 1 Apr 1 May i Precipitation PRECIPITATION Seasonal precipitation (October 1 October 1 to date in % of average through to the end of February) on this area was 60 percent 25 ___ ________ ____________ _ _ __ __ _ of normal. Precipitation last month was about 15 percent of 22 --__- ---------------- --- the month) average. Season precipitation at this time last 20 Y g p p 1 - year stood at 200 percent of normal. 150- 175 5 ,25- 100- 75-- Upper 2 7 Upper Feather Yuba American Mokelumne Sacramento ®WY 2017 _WY 2018 Reservoir Storage RESERVOIR STORAGEFirst of the month storage at Contents of major reservoirs in %of capacity 43 reservoirs was 10.60 million acre-feet which is 95 percent of average.About 65 percent of available capacity $ ___ ....... . ...... _ __ was being used. Storage in these reservoirs at this time last year was 120 percent of average. 60- 40- 20- Sacra- 4 2 Sacra- Yuba Stony Putah mento Feather American Cache Mokelumne ®WY 2017 _WY 2018 —a—10 Yr Avg Runoff RUNOFF Seasonal runoff of streams draining this area October 1 to date in % of average totaled 4.11 million acre-feet which is 50 percent of average. 450------------------------------------ Last year, runoff for the same period was 280 percent of 40 _- __-. . average. 350-- __ _. __-.E/z -_. 30 --_- - The Sacramento Region 40-30-30 Water Supply Index is 25 - - forecast to be 6.0 assuming median meteorological 200--conditions for the remainder of the year. This classifies the 15 .... - _ _ .- -- year as"dry" in the Sacramento Valley according 10 - - to the State Water Resources Control Board. 50-. - Shasta Inflow Feather Yuba American Mokelumne ®WY 2017 _WY 2018 8 SAN JOAQUIN RIVER AND TULARE LAKE REGIONS Snowpack Accumulation SNOWPACK- First of the month measurements made at 63 San Joaquin Region snow courses indicate an area Water Content in % of April 1 Average wide snow water equivalent of 5.8 inches. This is 250 15 percent of the seasonal April 1 average and 20 percent of 225 the March 1 average. Last year this time the pack was 200 Holding 54.3 inches of water. At the same time 36 175 150 / Tulare Lake snow courses indicate a basin-wide snow water 125 equivalent of 4.0 inches. This is 15 percent of the 100 seasonal April 1 average and 20 percent of the March 1 75 50 average. Last year this time the pack was holding 25 47.4 inches of water. 0 Jan 1 Feb 1 Mar 1 Apr 1 May 1 Precipitation PRECIPITATION Seasonal precipitation (October 1 October 1 to date in %of average through to the end of February) an the San Joaquin Region 30 - - - - - --- -- - - was 45 percent of normal. Precipitation last month was 25 - - --- -- --- - --- --- about 15 percent of the monthly average. Season 20precipitation at this time last year stood at 215 percent of -- - normal. Seasonal precipitation (October 1 through to the end 15 -- -- - - - - - -- of February) on the Tulare Lake Region was 30 percent of ° normal. Precipitation last month was about 20 percent of the 01 01 monthly average. Season precipitation at this time last year 5 _ -- - stood at 215 percent of normal. Stanislaus Merced Kings Tule Tuolumne San Joaquin Kaweah Kern ®WY 2017 _WY 2018 Reservoir Storage RESERVOIR STORAGE First of the month storage in Contents of major reservoirs in %of capacity 34 San Joaquin Region reservoirs was$ million acre-feet which is 110 percent of average. About 70 percent $ of available capacity was being used. Storage in these reservoirs at this time last year was 135 percent of average. s _ _ _ _ __ __ ___ _ __ First of the month storage in 6 Tulare Lake Region reservoirs was 830 thousand acre-feet which is 100 percent 4 of average. About 40 percent of available capacity was 2 - being used. Storage in these reservoirs at this time last year was 160 percent of average. 0- Stanislaus Merced Kings Tuolumne San Joaquin Kern ®WY 2017 _WY 2018 • A 10 Yr Avg Runoff RUNOFF- Seasonal runoff of streams draining the San October 1 to date in % of average Joaquin Region totaled 868 thousand acre-feet which is 50 45 -------- -------------------------- percent of average. Last year, runoff for the same period 4p - was 425 percent of average. Seasonal runoff of streams 35 __ __ __- -___--- --- 3o draining the Tulare Lake Region area totaled 311 thousand 25 acre-feet which is 50 percent of average. Last year, runoff 20 _ for the same period was 300 percent of average. 15 -- -- -- -- - -- - 10 , _ __ _ _ _ _ _ The San Joaquin Region 60-20-20 Water Supply Index is 5 __ _ __ __ forecast to be 1.8 assuming 75 percent of median meteorological conditions. This classifies the year as "critical"in Stanislaus Merced Kings Tule the San Joaquin according to the State Water Resources Tuolumne San Joaquin Kaweah Kern ®WY 2017 WY 2018 Control Board. 9 NORTH AND SOUTH LAHONTAN REGIONS Snowpack Accumulation SNOWPACK First of the month measurements made at Water Content in % of April 1 Average 11 North Lahontan Region snow courses indicate an area wide snow water equivalent of less than 7.2 inches. This is 250 225 20 percent of the seasonal April 1 average and 25 Zoo percent of the March 1 average. Last year this time the pack 175 was holding 47.5 inches of water. At the same iso - time 17 South Lahontan Region snow courses indicate a 125 basin-wide snow water equivalent of less 7.9 inches. 100 This is 30 percent of the seasonal April 1 average and 35 75 percent of the March 1 average. Last year this time the pack s0 25 -" was holding 45.8 inches of water. 0 i Jan 1 Feb 1 Mar 1 Apr 1 May 1 Precipitation PRECIPITATION Seasonal precipitation (October 1 October 1 to date in % of average through to the end of February) on the North Lahontan 25 ___________ __ _______- -- -_-- ----------- Region was 65 percent of normal. Precipitation last month 22 R ___ ____ _ __ ___20 _ __ __ _.___ ___ _ __ __ was about 35 percent of the monthly average. Season _ . _ . 1 _ _ . -. _.... __ _.. ..._.... precipitation at this time last year stood at 235 percent of 15 - - - - -- - - - - -.- normal. Seasonal precipitation (October 1 through to the end 12 of February) on the South Lahontan Region was 30 100 - - percent of normal. Precipitation last month was about 10 75- 50-- 5 . _ _ __ __- percent of the monthly average. Season precipitation at this 2 _ _ _ time last year stood at 165 percent of normal. Suprise Tahoe- Carson- Mono- Death Mojave Valley Truckee Walker Owners Valley Desert ®WY 2017 _WY 2018 Reservoir Storage RESERVOIR STORAGEFirst of the month storage Contents of major reservoirs in % of capacity in 5 North Lahontan Region reservoirs was 874 thousand - - _ acre-feet which is 165 percent of average. About 80 percent of available capacity was being used. Storage in these reservoirs at this time last year was 135 percent of average. First of the month storage in 8 South Lahontan Region reservoirs was 281 thousand acre-feet which is 105 percent a - of average.About 65 percent of available capacity was being used. Storage in these reservoirs at this time last year 20--- - - - - was 105 percent of average. Truckee East Walker Mono Basin Owens Basin ®WY 2017 _WY 2018 t 10 Yr Avg Runoff RUNOFF Seasonal runoff of streams draining the North October 1 to date in °J° of average Lahontan Region totaled 230 thousand acre-feet which is 45 ______________ .. ________ ___ ___ 120 percent of average. Last year, runoff for the same 400- �/ 35 period was 370 percent of average. Seasonal runoff of so --- -- -- __ _ -__ ._ __ _ - --- - -- _ streams draining the South Lahontan Region area totaled -- -- 25 - 60 thousand acre-feet which is 110 percent of average. Last 20 _ ____ __ _ _ _ _ __ -_ --_ __ _ _ year, runoff for the same period was 90 percent of average. 150- 100- 50- G_ 510 5 Truckee-Tahoe Carson Walker Owens to Farad ®WY 2017 _WY 2018 10 SAN FRANCISCO BAY AND CENTRAL COAST REGIONS Precipitation PRECIPITATION Seasonal precipitation (October 1 October 1 to date in % of average through to the end of February) on the San Francisco Bay 225- Region was 50 percent of normal. Precipitation last month 20 -- -- -- --- --------- -------- 17 was about 10 percent of the monthly average. Season 15 precipitation at this time last year stood at 200 percent of 12F//_____ normal. Seasonal precipitation (October 1 through to the end to - of February) on the Central Coast Region was 35 percent ____ _____ _____ ----- of normal. Precipitation last month was about 5 percent of 50- _ __._ -- __.__ . . _ . the monthly average. Season precipitation at this time last 2 __ _ year stood at 195 percent of normal. San Francisca Paiaro Salinas SantaMaria- Bay Santa Ynez ®M2017 WY 2018 Reservoir Storage RESERVOIR STORAGEFirst of the month storage Contents of major reservoirs in %of capacity in 17 San Francisco Region 43 reservoirs was 388 10 _ - ___ - _- -- --- thousand acre-feet which is 75 percent of average. About 55 $ __ __ ___.___. percent of available capacity was being used. Storage in these reservoirs at this time last year was 120 percent of 6 -- -..-- - -- --- average. First of the month storage in 6 Central Coast Region reservoirs was 350 thousand acre-feet which is 55 a - - -- percent of average. About 35 percent of available capacity 2 was being used. Storage in these reservoirs at this time last year was 100 percent of average. North Bay Southeast Peninsula Salinas Santa Ynez Bay ®WY 2017 _WY 2018 k •10 Ys Avg Runoff RUNOFF Seasonal runoff of streams draining the San October 1 to date in % of average Francisco Region totaled 4.0 thousand acre-feet million 35 ---------- - acre-feet which is 10 percent of average. Last year, runoff 30 --- ------ - - for the same period was 260 percent of average. Seasonal 25 -- - - runoff of streams draining the Central Coast Region area 20 - -- totaled 13 thousand acre-feet million acre-feet which is 5 15 - -- _-.-,.- .- percent of average. Last year, runoff for the same period was 325 percent of average. 10 --- --- --- --- 50-- -- --5 _ ____ _ ---- -- 0- Napa -__ -Napa near Arroyo Seco Naeimiento St.Helena near Soledad ®WY 2017 _WY 2018 SOUTH COAST AND COLORADO RIVER REGIONS PRECIPITATION-October through February(seasonal) precipitation on the South Coast Region was 25 percent of normal. February precipitation was 10 percent of the monthly average. Seasonal precipitation at this time last year was 175 percent of normal. Seasonal precipitation on the Colorado River-Desert Region was 30 percent of normal and last year's seasonal precipitation on the Colorado River-Desert Region was 170 percent of normal. Precipitation in February was 10 percent of average. RESERVOIR STORAGE- March 1 storage in 29 major South Coast Region reservoirs was 1,18 million acre-feet or 85 percent of average. About 55 percent of available capacity was being used. Storage in these reservoirs at this time last year was about 95 percent of average. On March 1 combined storage in Lakes Powell, Mead, Mohave and Havasu was about 26.3 million acre-feet or about 70 percent of average. About 50 percent of available capacity was in use. Last year at this time, these reservoirs were storing about 24.3 million acre-feet. RUNOFF-Seasonal runoff from selected South Coast Region streams is 4 thousand acre-feet for 5 percent of average. Seasonal runoff from these streams last year was 105 percent of average. COLORADO RIVER- The April -July inflow to Lake Powell is forecast to be 3.4 million acre-feet,which is 47 percent of average. The March 1 snowpack was 70 percent, highest in the Upper Green at 110 percent of average and lowest on the Animas, Colorado River Plateaus and Price/San Rafael at 45%. 12 MAJOR WATER DISTRIBUTION PROJECTS RESERVOIR STORAGE (AVERAGES BASED ON 1966-2015 OR PERIOD RECORD) AVERAGE STORAGE AT END OF February RESERVOIR CAPACITY STORAGE 2017 2018 PERCENT PERCENT 1,000 AF 1,000 AF 1,000 AF 1,000 AF AVERAGE CAPACITY STATE WATER PROJECT Lake Oroville 3,538 2,442 2,706 1,460 60% 41% San Luis Reservoir(SWP) 1,062 914 1,068 697 76% 66% Lake Del Valle 77 35 40 26 75% 344/4 Lake Silverwood 78 67 70 71. 106% 91% Pyramid Lake 180 163 165 166 102% 92% Castaic Lake 325 277 301 262 95% 81% Perris Lake 131 105 58 74 71% 57% CENTRAL VALLEY PROJECT Trinity Lake 2,448 1,771 1,922 1,787 101% 73% Lake Shasta 4,552 3,284 3,779 3,414 104% 75% Whiskeytown Lake 241 207 224 206 99% 85% Folsom Lake 977 537 404 526 98% 54% New Melones Reservoir 2,400 1,456 1,578 1,920 132% 80% Millerton Lake 521 335 421 329 98% 63% San Luis Reservoir(CVP) 971 786 923 841 107% 87% COLORADO RIVER PROJECT Lake Mead 26,159 19,321 10,838 10,703 55% 41% Lake Powell 24,322 16,732 11,217 13,346 80% 55% Lake Mohave 1,810 1,672 1,690 1,704 102% 94% Lake Havasu 648 555 586 590 106% 91% EAST BAY MUNICIPAL UTILITY DISTRICT Pardee Res 204 180 204 186 1.03% 91% Camanche Reservoir 417 250 396 303 1.21% 73% East Bay(4 res.) 159 130 146 122 94% 77% CITY AND COUNTY OF SAN FRANCISCO Hetch-Hetchy Reservoir 360 171 311 289 169% 80% Cherry Lake 268 155 238 48 31% 18% Lake Eleanor 29 11 22 9 77% 30% South Bay/Peninsula(4 res.) 238 166 181 130 78% 54% CITY OF LOS ANGELES(D.W.P.) Lake Crowley 183 126 128 136 108% 74% Grant Lake 48 28 27 20 74% 43% Other Aqueduct Storage(6 res.) 238 166 181 130 78% 54% 13 TELEMETERED SNOW WATER EQUIVALENTS March 1,2018 (AVERAGES BASED ON PERIOD RECORD) INCHES OF WATER EQUIVALENT BASIN NAME APRIL 1 PERCENT 24 HRS 1 WEEK STATION NAME ELEV AVERAGE Mar 1 OF AVERAGE PREVIOUS PREVIOUS TRINITY RIVER Shimmy Lake 6400' 40.3 1.4 3.5 0.5 0.6 Crowder Flat 5100' 0.9 - 0.8 0.0 Highland Lakes 6030' 29.9 2.6 8.8 1.9 1.0 Mumbo Basin 5650' 22.4 0.6 2.7 0.0 0.0 Bonanza King 6450' 40.5 - - - - Red Rock Mountain 6700' 39.6 14.2 35.7 12.2 10.7 Big Flat 5100' 15.8 4.7 29.6 4.0 2.8 Scott Mountain 5900' 16.0 1.3 8.3 0.8 1.1 Peterson Flat 7150' 29.2 2.7 9.1 2.1 1.0 Middle Boulder 3 6200' 28.3 1.7 6.0 1.5 1.8 SACRAMENTO RIVER Blacks Mountain 7050' 12.7 2.4 18.9 2.3 1.0 Cedar Pass 7100' 18.1 8.6 47.5 8.2 6.4 Medicine Lake 6700' 32.6 5.5 16.9 5.5 5.5 Sand Flat 6750' 42.4 - - - - Slate Creek 5700' 29.0 1.7 5.8 0.8 0.2 Adin Mountain 6200' 13.6 4.3 31.6 3.3 2.0 Stouts Meadow 5400' 36.0 5.8 16.0 4.7 3.8 Snow Mountain 5950' 27.0 6.1 22.7 5.6 5.9 FEATHER RIVER Kettle Rock 7300' 25.5 4.1 16.0 3.9 2.5 Gold Lake 6750' 36.5 8.9 24.3 8.5 8.2 Bucks Lake 5750' 44.7 5.9 7.3.2 4.8 3.8 Harkness Flat 6200' 28.5 3.4 12.1 2.9 2.7 Four Trees 5150' 20.0 3.2 16.2 1.6 0.0 Humbug 6500' 28.0 5.3 18.9 4.9 4.9 Grizzly Ridge 6900' 29.7 5.0 17.0 4.9 3.7 Rattlesnake 6100' 7.4.0 1.2 8.6 0.7 0.4 Lower Lassen Peak 8250' - 25.4 - 24.9 29.7 Pilot Peak 6800' 52.6 4.9 9.2 4.3 2.3 EEL RIVER Noel Spring 5100' - 0.4 - 0.1 0.0 YUBA &AMERICAN RIVERS Carson Pass 8353' - 11.7 11.1 10.3 Lake Lois 8600' 39.5 - - - Forni Ridge 7600' 37.0 - Silver Lake 7100' 22.7 - Blue Canyon 5280' 9.0 - - - - Schneiders 8750' 34.5 18.9 54.9 18.4 17.2 Meadow Lake 7200' 55.5 - - - - Robbs Powerhouse 5150' 5.2 3.2 61.2 2.8 1.3 Robinson Cow Camp 6480' - 6.0 - 5.2 3.6 Cent Sierra Snow Lab 6900' 33.6 4.9 14.6 4.4 3.3 Caples Lake 8000' 30.9 6.6 21.4 6.2 5.0 Alpha 7600' 35.9 3.2 9.0 3.1 2.4 Robbs Saddle 5900' 21.4 2.9 13.5 2.3 0.9 Huysink 6600' 42.6 3.5 8.2 3.1 1.7 Van Vleck 6700' 35.9 7.7 21.4 7.0 4.8 Greek Store 5600' 21.0 4.0 18.9 3.7 1.8 MOKELUMNE&STANISLAUS RIVERS Highland Meadow 8700' 47.9 14.9 31.0 13.9 12.8 Gianelli Meadow 8400' 55.5 11.5 20.8 11.4 10.6 Bloods Creek 7200' 35.5 0.3 0.8 - - Blue Lakes 8000' 33.1 8.3 24.9 7.6 6.4 Mud Lake 7900' 44.9 - - - Black Springs 6500' 32.0 3.5 10.9 3.1 2.3 Stanislaus Meadow 7750' 47.5 8.5 17.9 8.4 8.0 Deadman Creek 9250' 37.2 10.0 26.8 9.7 8.5 Lower Relief Valley 8100' 41.2 8.3 20.0 8.0 8.5 TUOLUMNE&MERCED RIVERS Dana Meadows 9800' 27.7 10.3 37.3 10.2 9.4 Horse Meadow 8400' 48.6 19.9 40.9 19.6 18.1 Tuolumne Meadows 8600' 22.6 4.7 21.0 4.8 4.6 Slide Canyon 9200' 41.1 16.3 39.7 16.1 14.9 Ostrander Lake 8200' 34.8 7.2 20.7 7.0 5.7 Gin Flat 7050' 34.2 2.5 7.2 2.3 0.8 Tenaya Lake 8150' 33.1 6.7 20.1 6.2 5.2 White Wolf 7900' - 3.0 - 2.8 3.2 Lower Kibbie Ridge 6700' 27.4 1.9 6.9 1.7 1.0 Paradise Meadow 7650' 41.3 9.3 22.4 8.8 7.0 14 SAN JOAQUIN RIVER Volcanic Knob 10050' 30.1 7.9 26.2 7.8 6.6 Tamarack Summit 7559 30.5 1.2 3.9 1.1 0.0 Kaiser Point 9200' 37.8 10.3 27.3 10.2 9.8 Huntington Lake 7000' 20.1 2.5 12.5 2.4 1.6 Green Mountain 7900' 30.8 4.3 14.0 4.3 4.0 Poison Ridge 6900' 28.9 2.6 9.1 2.8 2.4 Graveyard Meadow 6900' 18.8 1.0 5.1 0.8 0.0 Agnew Pass 9450' 32.3 12.6 38.9 12.5 10.0 Devils Postpile 7569' - 1.2 0.7 0.3 Chilkoot Meadow 7150' 38.0 0.5 1.3 0.5 0.0 KINGS RIVER Bishop Pass 11200' 34.0 4.1 12.1 4.1 3.7 Blackcap Basin 10300' 34.3 - - Mitchell Meadow 9900' 32.9 10.2 31.0 10.1 9.6 Upper Burnt Corral 9700' 34.6 7.8 22.6 7.7 6.7 State Lakes 1.0300' 29.0 10.6 36.5 10.4 8.5 West Woodchuck Meadow 9100' 32.8 1.2 3.5 1.2 0.5 Big Meadows 7600' 25.9 - - - - Charlotte Lake 10400' 27.5 0.9 KAWEAH&TULE RIVERS Farewell Gap 9500' 34.5 - - - - Giant Forest 6650' 10.0 1.7 16.8 1.6 0.9 Quaking Aspen 720Y 21.0 4.8 23.0 4.8 2.8 KERN RIVER Tunnel Guard Station 8900' 15.6 - - - Beach Meadows 7650' 11.0 1.3 12.0 0.8 0.6 Upper Tyndall Creek 11400' 27.7 3.1 11.2 3.1 2.8 Casa Vieja Meadows 8300' 20.9 4.8 23.1 - - Pascoes 9150' 24.9 1.5 6.1 1.6 1.6 Wet Meadows 8950' 30.3 1.4 4.6 1.4 0.2 Chagoopa Plateau 10300' 21.8 8.8 40.1 9.1 8.7 Crabtree Meadow 10700' 19.8 - SURPRISE VALLEY AREA Dismal Swamp 7050' 29.2 12.6 43.2 12.3 10.8 TRUCKEE RIVER Independence Camp 7000' 21.8 5.4 24.8 5.1 2.4 Independence Lake 8450' 41.4 12.2 29.5 12.1 11.2 Squaw Valley Gold Coast 8200' 46.5 - - - 15.5 Truckee 2 6400' 14.3 3.8 26.6 3.4 1.5 Independence Creek 6500' 12.7 2.6 20.5 2.3 0.9 Big Meadows 8700' 25.7 - - - 8.0 LAKE TAHOE BASIN Rubicon Peak 2 7500' 29.1 3.1 10.7 2.6 1.3 Tahoe City Cross 6750' 16.0 1.5 9.4 1.3 0.6 Echo Peak 5 7800' 39.5 - - - 10.5 Hagans Meadow 8000' 16.5 2.2 13.3 1.9 0.0 Fallen Leaf Lake 6250' 7.0 1.0 14.3 0.6 0.0 Ward Creek 3 6750' 39.4 9.1 23.1 8.3 6.1 Mount Rose Ski Area 8900' 38.5 16.0 46.8 17.7 16.7 Heavenly Valley 8800' 28.1 11.9 42.3 11.5 8.8 Marlette Lake 8000' 21.1 6.0 28.4 5.8 - CARSON RIVER Spratt Creek 6150' 4.5 1.3 28.9 1.0 0.3 Horse Meadow 8400' 48.6 19.9 40.9 19.6 18.1 Burnside Lake 8129' - 8.4 - 7.6 5.5 Monitor Pass 8350' - 5.6 - 5.3 4.7 Poison Flat 7900' 16.2 5.3 32.7 4.5 0.0 Forestdale Creek 8017' - - - - 7.9 Ebbetts Pass 8700' 38.8 - - - WALKER RIVER Sonora Pass Bridge 8750' 26.0 7.2 27.7 7.1 6.1 Virginia Lakes Ridge 9300' 20.3 5.7 28.1 5.4 3.4 Lobdell Lake 9200' 17.3 5.8 33.5 5.7 5.0 Summit Meadow 9313' - 6.8 - 6.6 5.5 Leavitt Meadows 7200' 8.0 0.3 3.8 0.4 0.3 Leavitt Lake 9600' - 22.4 - 21.4 19.7 OWENS RIVERIMONO LAKE Cottonwood Lakes 10150' 11.6 4.2 36.1 4.8 - Gem Pass 10750' 31.7 8.1 25.5 8.0 7.7 Rock Creek Lakes 9700' 14.0 2.2 15.6 2.1 0.8 South Lake 9600' 16.0 3.7 23.3 3.7 3.0 Big Pine Creek 9800' 17.9 2.5 14.0 2.4 1.7 Sawmill 10200' 19.4 4.1 21.3 4.0 3.1 NORMAL SNOWPACK ACCUMULATION EXPRESSED AS A PERCENT OF APRIL 1ST AVERAGE AREA JANUARY FEBRUARY MARCH APRIL MAY Central Valley North 45% 70% 90% 100% 75% Central Valley South 45% 65% 85% 100% 80% North Coast 40% 60% 85% 100% 80% 15 March 1 Statewide Conditions 300 270 250 a} 200 0 150 130 12325 14305 a ... 0000 100 8080 8080 8075 60 901 85 7070 65 65 - cJQ 5 50 45 45 30, L35 20Ik5 1520 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 I I Snowpack [. 1 Precipitation �Runoff to Date Reservoir Storage SNOWLINES Registration is now open for the 86th annual Western Snow Conference to be held in Albuquerque, NM April 16-19, 2018. We expect to have a full agenda of informative and interesting presentations related to snow hydrology, meteorological measurement techniques, and water resource management. Meeting Information: http://www.westernsnowconference.org/meetings/2018 The Conference will begin Monday, April 16th with a short course "Communicating Complex Environmental Information to Broad Audiences". Tuesday and Wednesday will include formal paper and poster presentations on a variety of topics, including climate variability, climate change impacts on snow and runof, water management, water supply forecasting, and modeling and climatology of snow. Thursday will include a technical tour of the nearby Rio Grande Valley Pictured on this month's cover is the Gin Flat Snow Sensor in Yosemite National Park following the February 28 through March 5 storm which increased the snow water equivalent at this site by nearly 8". Photo by Harrison Forrester, Hydrologist, Yosemite National Park... 16 @WR OSP 18 144527 SNOWPACK-Snow data is a major index of spring and summer runoff from Sierra Nevada watersheds. April 1 data historically reflects the magnitude of the snowpack at or near the maximum seasonal accumulation. Averages are based on April 1 data for the period 1966-2015 (50 years, except for data sites established after 1951). PRECIPITATION -Averages for stations are based on the source of the data and varies from a 30 year to a 50 year period. RUNOFF AND FORECASTS -Runoff data and runoff forecasts are shown as unimpaired values. Unimpaired runoff represents the natural water production of a river basin, unaltered by upstream diversions, storage, or by export or import of water to or from other watersheds. Forecast of runoff assumes median conditions subsequent to the date of forecast. Runoff probability ranges are statistically derived from historical data. The 80 percent probability range is comprised of the 90 percent exceedence level value and the 10 percent exceedence level value. This means that actual runoff should fall within the stated limits eight times out of ten. Runoff averages for most streams are based on the period 1966-2015. Reservoir storage averages are based on the period from 1966 (or beginning of operation) to 2015. For more details contact California Cooperative Snow Surveys, P.O. Box 219000, Sacramento, CA 95821-9000, (916) 574-2983 or daver@water.ca.gov. INDICES OF WATER AVAILABILITY The Sacramento River water year unimpaired runoff is the sum of: Sacramento River above Bend Bridge, Feather River Inflow to Lake Oroville, Yuba River near Smartville and American River Inflow to Folsom Lake. The Sacramento Valley Water Year Hydrologic Classifi ation 40-30-30 Index). The values 40-30-30 represent the percentage weight given to the three variables in the formula for the index. The first variable is the forecasted unimpaired runoff from April through July (40 percent). The second variable is the forecasted unimpaired runoff from October through March (30 Percent). The third variable is the previous year's index with a cap to account for required flood control releases during wet years. The basins used in this computation are those used in the Sacramento River water year unimpaired runoff. The San Joaquin Valley Water Year Hydrologic Classification 60-20-20 Index). In a similar manner the values 60-20-20 represents the percentage weights on April through July runoff, October through March runoff and previous year's Index. The San Joaquin River unimpaired runoff is the sum of: Stanislaus River Inflow to New Melones Lake, Tuolumne River Inflow to New Don Pedro Reservoir, Merced River Inflow to Lake McClure and San Joaquin River Inflow to Millerton Lake. Runoff of the eight major rivers of the Sacramento and San Joaquin Regions is the sum of the runoff in the eight major rivers used in the two above indices. State of California — The Natural Resources Agency DEPARTMENT OF WATER RESOURCES FIRST CLASS MAIL P.O. Box 942836 U.S.POSTAGE BUTTE COUNTY PAID Sacramento, CA 94236-0001 ADMINISTRATION' SACRAMENTO CA PERMIT NO 424 MAR 2 3 2818 OROVILLE"CALIFORNIA BUTTE COUNTY _ CHAIRMAN-BD OF SUPERVISORS 25 COUNTY CENTER DR OROVILLE CA 95965-3316 FI' rst S�pL OF !H w m s � o IQs c'�LIFORN�P