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Home My WebLink AboutWater Conditions in CA - Report 1 h ✓/h� � � s r a G/��. mk�i.m tie �l F�r y, fl»�YJ��%i�p r �/! f1�.� i �� ✓ ! �,,�,'�� . � 1�- i Til/i�/ �� m� fJ��j,!y/�{�i� '1� y�/ ��^3 I� i 1k� s i • � a� warp a� and 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 Acting Deputy Director Chief Counsel Division of Flood Management Jeremy Arrich................................................................Acting Chief, Division of Flood Management MauryRoos..............................................................................................................State Hydrologist Jon Ericson...........................................................................Chief, Hydrology and Flood Operations Sudhakar Talanki.........................................................................................Chief, Hydrology Branch Prepared by Frank Gehrke...........................................................................................Chief, Coop Snow Surveys DaveRizzardo..................................................................................................Chief, Snow Surveys SeanDeGuzman........................................................................................................Engineer, W.R. StephenNemeth.........................................................................................................Engineer, W.R. JohnKing....................................................................................................................Engineer, W.R. AndrewReising...........................................................................................................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 District 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 E i Summary of Water Conditions February 1, 2018 What a contrast in water years! Last year was one of the wettest; this water year seems to be shaking out as one of the driest, although not quite as low as in 1977 or more recently in 2014. Residual watershed moiture from 2017 is helping to maintain base streamflows above what would otherwise be expected with the low precipitation. Forecasts of median April through July runoff are expected to be about 55 percent of average compared to last year's 145 percent forecast on this date and an eventual actual 190 percent amount for the snowmelt season. Total statewide runoff in the 2017 water year was estimated to be 215 percent of average. Snowpack water content is quite low at about 25 percent of average for this date compared to 185 percent a year ago. The pack is about 15 percent of the April 1 average, normally the date of maximum accumulation. Regional February 1 amounts range from about 20 percent to 30 percent, with somewhat higher percentages at higher elevations and on the east side and some lower elevation courses bare in the southern Sierra. Precipitation from October through January was about 60 percent statewide compared to 180 percent last year. This year the lowest percentages are in the south and higher in the north at around 80 percent. Runoff to date has been about 55 percent of average statewide compared to 215 last year on this date. Estimated January runoff was about 45 percent. Estimated runoff of the eight major rivers of the Sacramento-San Joaquin region in January was 1.45 million acre-feet. Reservoir storage is about 105 percent of average, compared to 115 percent last year when many were in the flood control mode. Storage at Lake Oroville on February 1 was about 1.4 million acre-feet less than last year. If storage there was normal, it would raise the statewide storage about 4 percent. SUMMARY OF WATER CONDITIONS IN PERCENT OF AVERAGE PRECIPITATION FEBRUARY I FEBRUARY 1 RUNOFF APRIL-JULY WATER YEAR HYDROLOGIC REGION OCTOBER 1 SNOW WATER RESERVOIR OCTOBER 1 RUNOFF RUNOFF TO DATE CONTENT STORAGE TO DATE FORECAST FORECAST NORTH COAST 80 15 100 40 45 50 SAN FRANCISCO BAY 60 - 85 10 -- - CENTRAL COAST 45 -- 65 10 - -- SOUTH COAST 30 __ 85 5 SACRAMENTO RIVER 70 20 100 60 60 65 SAN JOAQUIN RIVER 60 15 120 65 55 60 TULARE LAKE 35 10 105 65 50 50 NORTH LAHONTAN 70 15 175 135 60 70 SOUTH LAHONTAN 40 20 100 120 55 65 COLORADO RIVER 35 STATEWIDE 60 15 105 55 55 60 1 FEBRUARY 1, 2018 FORECASTS APRIL-JULY UNIMPAIRED RUNOFF Unimpaired Runoff in 1,000 Acre-Feet (1) HYDROLOGIC REGION HISTORICAL FORECAST and Watershed 50 Yr Max of Min of Apr-Jul Pct 80% Avg Record Record Forecast of Probability (2) (10) (10) Avg Range(1) North Coast Trinity River at Lewiston Lake 639 1,593 80 300 47% 200 - 420 SACRAMENTO RIVER Upper Sacramento River Sacramento River at Delta above Shasta Lake 295 751 39 165 56% McCloud River above Shasta Lake 385 850 185 340 88% Pit River near Montgomery Creek+Squaw Creek 1,020 2,098 480 910 89% Total Inflow to Shasta Lake 1,756 3,525 711 1,440 82% 1,160 - 1,750 Sacramento River above Bend Bridge,near Red Bluff 2,421 5,117 943 1,720 71% 1,340 - 2,130 Feather River Feather River at Lake Almanor near Prattville (3) 333 675 120 190 57% North Fork at Pulga (3) 1,028 2,416 243 500 49% Middle Fork near Clio (4) 86 518 4 35 41% South Fork at Ponderosa Dam (3) 110 267 13 45 41% Feather River at Oroville 1,704 4,676 378 880 52% 600 - 1,180 Yuba River North Yuba below Goodyears Bar 279 647 51 160 57% Inflow to Jackson Mdws and Bowman Reservoirs (3) 112 236 25 65 58% South Yuba at Langs Crossing (3) 233 481 57 130 56% Yuba River near Smartsville plus Deer Creek 968 2,424 151 580 60% 410 - 810 American River North Fork at North Fork Dam (3) 262 716 43 140 53% Middle Fork near Auburn (3) 522 1,406 100 310 59% Silver Creek below Camino Diversion Dam (3) 173 386 37 90 52% American River below Folsom Lake 1,199 3,074 185 670 56% 460 - 950 SAN JOAQUIN RIVER Cosumnes River at Michigan Bar 125 446 8 60 48% 40 - 100 Mokelumne River North Fork near West Point (5) 437 829 104 250 57% Total Inflow to Pardee Reservoir 457 1,076 75 270 59% 210 - 370 Stanislaus River Middle Fork below Beardsley Dam (3) 334 702 64 190 57% North Fork Inflow to McKays Point Dam (3) 224 503 34 120 54% Stanislaus River below Goodwin Reservoir(9) 682 1,710 116 370 54% 300 490 Tuolumne River Cherry Creek&Eleanor Creek near Hetch Hetchy 315 727 97 190 60% Tuolumne River near Hetch Hetchy 604 1,392 153 370 61% Tuolumne River below La Grange Reservoir(9) 1,193 2,682 301 720 60% 590 - 940 Merced River Merced River at Pohono Bridge 372 888 80 210 56% Merced River below Merced Falls(9) 623 1,587 104 330 53% 270 - 430 San Joaquin River San Joaquin River at Mammoth Pool (7) 1,026 2,279 235 580 57% Big Creek below Huntington Lake (8) 91 264 11 45 49% South Fork near Florence Lake (7) 201 511 58 120 60% San Joaquin River inflow to Millerton Lake 1,228 3,355 193 680 55% 520 - 860 TULARE LAKE Kings River North Fork Kings River near Cliff Camp (3) 239 565 50 120 50% Kings River below Pine Flat Reservoir 1,210 3,113 208 640 53% 470 - 810 Kaweah River below Terminus Reservoir 285 814 42 120 42% 90 160 Tule River below Lake Success 63 259 1 18 29% 11 30 Kern River Kern River near Kernville 384 1,203 83 190 49% Kern River inflow to Lake Isabella 458 1,657 57 220 48% 150 - 300 (1)See inside back cover for definition (5)36 year average based on years 1936-72 (2)All 50 year averages are based on years 1966-2015 (6)45 year average based on years 1936-81 unless otherwise noted (7)50 year average based on years 1953-2002 (3)50 year average based on years 1941-90 (8)50 year average based on years 1946-1995 (4)44 year average based on years 1836-79 4 FEBRUARY 1, 2018 FORECASTS WATER YEAR UNIMPAIRED RUNOFF 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 (2) (10) (10) Jan* 1 . 1 1 Forecast Avg Range (1) 1348 2990 200 135 100 151 125 120 45 10 3 1 690 51% 500 920 860 1,965 165 1,183 2,353 557 3,002 5,150 1,484 5,831 10,796 2,479 1,156 540 684 530 420 270 220 185 185 4,190 72% 3,590 - 4,850 8,544 17,180 3,294 1,582 760 968 645 490 335 250 235 235 5,500 64% 4,630 - 6,440 780 1,269 366 2,417 4,400 666 219 637 24 291 562 32 4,407 10,178 994 843 405 552 360 290 140 90 75 65 2,820 64% 2,190 - 3,500 564 1,056 102 181 292 30 379 565 98 2,268 5,604 369 488 210 289 245 240 75 20 12 11 1,590 70% 1,260 - 2,030 616 1,234 66 1,070 2,575 144 318 705 59 2,626 7,391 349 502 230 340 290 280 85 15 4 4 1,750 67% 1,350 - 2,280 379 1,253 20 43 35 57 33 20 6 1 0 0 195 51% 140 - 300 626 1,009 197 748 1,901 129 106 45 67 100 130 35 5 1 1 490 66% 400 - 640 471 929 88 1,149 3,078 155 154 65 114 145 160 55 10 4 3 710 62% 600 - 890 461 1,147 123 770 1,661 258 1,909 4,631 383 229 95 163 220 330 150 20 8 5 1,220 64% 1,040 - 1,530 461 1,020 92 992 2,787 150 73 45 77 115 150 55 10 4 1 530 53% 440 - 670 1,337 2,964 308 112 298 14 248 653 71 1,793 4,642 327 130 60 118 180 280 170 50 14 8 1,010 56% 800 - 1,250 284 607 58 1,702 4,287 359 116 45 95 170 285 145 40 15 9 920 54% 700 - 1,140 451 1,402 89 28 14 30 40 55 20 5 2 1 195 43% 150 - 260 147 615 10 13 5 9 9 7 2 0 0 0 45 31% 30 - 70 558 1,577 163 728 2,318 130 103 25 35 55 80 60 25 13 9 405 56% 300 - 520 (9)Forecast point 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 FEBRUARY 1,2018 FORECASTS APRIWULY UNIMPAIRED RUNOFF Apr-Jul Unimpaired Runoff in 1,000 Acre-Feet(1) HYDROLOGIC REGION HISTORICAL FORECAST and Watershed 50 Yr Max Min Apr-JulEof, C Avg of of Forecasts(2) Record Record v NORTH COAST Scott River Scott River nr Ft Jones(3) 173 398 22 65 38% Klamath River Total inflow to Upper Klamath Lake (4) 475 1,150 149 275 58% NORTH LAHONTAN Truckee River Lake Tahoe to Farad accretions 250 713 48 130 52% Lake Tahoe Rise(assuming gates closed,ft) 1.3 5.4 0.2 0.9 67% Carson River West Fork Carson River at Woodfords 52 135 10 35 67% East Fork Carson River near Gardnerville 182 480 43 120 66% Walker River West Walker River below Little Walker,near Coleville 153 410 35 95 62% East Walker River near Bridgeport 61 209 7 34 56% SOUTH LAHONTAN Owens River Total tributary flow to Owens River (5) 231 579 84 119 51% (1)See inside back cover for definition (2)All 50 year averages are based on years 1966-2015 unless otherwise noted (3)Forecast by National Weather Service Califomia-Nevada River Forecast Center. 30 yr average(1981-2010) (4)Forecast by 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 1965.2015. 6 NORTH COAST REGION Snowpack Accumulation SNOWPACK First of the month measurements made at 11 snow courses indicate an area wide snow water Water Content in % of April 1 Average equivalent of less than 4.6 inches. This is 15 percent of the 250 seasonal April 1 average and 25 percent of the February 1 225 average. Last year this time the pack was holding 200 _ .._-::: ... .. 23.8 inches of water. 175 150 ..., ............ .. ...... ... ... ...... .... ................ ..... .. 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 January) on this area was 80 percent 17---- ---- -- ---- -- ---- ---- -- - - --- ----- of normal. Precipitation last month was about average. 150-- - _ - - - - _ - - - - --- Season precipitation at this time last 12 year stood at 150 percent of normal. 100- 75-- 50-- 25- 0 7 5 - 2 Smith Klamath Trinity Eel Russian ®WY 2017 WY 2018 Reservoir Storage RESERVOIR STORAGE- First of the month storage Contents of major reservoirs in %of capacity at 6 reservoirs was 2.11 million acre-feet which is 100 100-- ------ ----- -- ------ ---- -- --------- percent of average. About 70 percent of available capacity 80 was being used. Storage in these reservoirs at this time ____ _ ___ __ __ _ _ last year was 90 percent of average. 6 - - ---- - - -- - -- -- 2 - - - Klamath Trinity Eel Russian ®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 2.03 million acre-feet which is 40 percent of 25 -- ----- -- ----- - ----- ------ -" average. Last year, runoff for the same period was 190 22 ---- - -- ------------- - ----- 20 __ ___ _ _ ____ ____ ___ 7- percent of average. 17 --� -- -- - - - -- - 15 ---- ----- --- 125-- - -- -- ----- - -- 100- ---- -- --- ----- -- 7 ---- ----- ----- 2 - - - Klamath,Copco Trinity Eel Russian to Orleans ®WY 2017 _WY 2018 7 SACRAMENTO RIVER REGION^��OyyO�C� �rCUO0U|��.(]� ~ - ' '` ' `~Accumulation SNOWPACK- First ofthe month measurements made m1 Water Content iO % of April 1Average 68 snow courses indicate an area wide snow water zm _ -.......... ...... ....... ............. ..... __ equivalent of4.Qinches.This is2Upercent ofthe 225 --'---. -' - _ ------ seasonal April 1average and 3Opercent ofthe February 1 um '� average, Last year this time the pack was holding on -��- - —' ---' ~"'—'- - �� -� -- ' 282inches ofwater. 150 - -- � �� —� ------- z25 -�_�-~�� _�-- ............-.................. -- ..... um ----'-- --'- n 50 25 n Jan 1 Fem1 war I Apr 1 May PreGipitation 3��0�3ea�ona| preuo�udon �Ookuber1 October 1 &odate in9�ofaverage PRECIPITATION""^" ''�� (October through bothe end ofJanuary) onthis area was 7Opercent uu ^ ofnormal. Precipitation last month was about 80percent of ^`- the monthly average. Season precipitation at this time last - year stood atl80percent nfnormal. 150 100- Upper Feather Yuba American Mnk,-Iumne Sacramento =w'mn, WY 2018 Reservoir Storage RESERVOIR STORAGE- Fintofthemonthotormge Contents ofmajor reservoirs in% of capacity o143 reservoirs was 10.49 million acre-feet which is 100 100 percent ofaverage. About G5percent ofavailable capacity was being used. Storage in these reservoirs at this time last year was 120percent nfaverage. Sacra- Putah mento '~""~' American ^="° Moke.umn^ WY 2017 *Y 2018 —A—'`ooAvg Runoff Do�ober1 �odm�w |n96o�averaga ��FF- seasonal runoff ufstreams draining this area totaled 3.42million acre-feet which ioGDpercent of 400 average. Last year, runoff for the same period was 32O xo percent nfaverage. 250-- - -------------E// TheSacramento Region 4D-30'30 Water Supply Index |s forecast to bo6.7assuming median meteorological 1 conditions for the remainder ofthe year. This o|ass�iesthe year ms"below normal" inthe Sacramento Valley according 100- to the State Water Resources Control Board. Shasta Inflow Feather Yuba American Mokalumne WY 2017 WY 2018 8 SAN JOAQUIN RIVER AND TULARE LAKE REGIONS Snowpack Accumulation SNOWPACK- First of the month measurements made at 65 San Joaquin Region snow courses indicate an area Water Content in % of April 1 Average wide snow water equivalent of 4.7 inches. This is 250 . . . 15 percent of the seasonal April 1 average and 20 percent 225 - ... ..... .... ............. 200 - of the February 1 average. Last year this time the pack 175 was holding less than 37.2 inches of water. At the same ISO.- .............. ..... ..... time 41 Tulare Lake snow courses indicate a basin-wide 125 snow water equivalent of 3.0 inches. This is 10 100 ............ percent of the seasonal April 1 average and 20 percent of 75 ......................... ...... .................... .................... the February 1 average. Last year this time the pack was 50 . ..... ....... .... ------- holding 33.1 inches of water. 25 ... ... .... ............ 0 Jan I Feb 1 Mar I Apr 1 May 1 Precipitation PRECIPITATION-Seasonal precipitation (October 1 October 1 to date in % of average through to the end of January) on the San Joaquin 300--- - - - - -- - -- -- ------ - ----- -- --- - - ---- Region was 60 percent of normal. Precipitation last month 25G-- -- --------------- ----- -------- was about 80 percent of the monthly average. Season 20precipitation at this time last year stood at 200 percent of 0--- normal. Seasonal precipitation (October 1 through to the 150- end of January) on the Tulare Lake Region was 35 100- percent of normal. Precipitation last month was about 55 percent of the monthly average. Season precipitation at 50- this time last year stood at 225 percent of normal. 07' M7 Stanislaus Merced Kings Tula Tuolumne San Joaquin Kaweah Kern ®WY 2017 WY 2018 Reservoir Storage RESERVOIR STORAGE- First of the month storage Contents of major reservoirs in %of capacity in 34 San Joaquin Region reservoirs was 8.29 million 100--- -------------------- ------------- acre-feet which is 120 percent of average. About 70 80-------- ------------- - ---- ------ - percent of available capacity was being used. Storage in these reservoirs at this time last year was 115 percent of 60---- --------- average. First of the month storage in 6 Tulare Lake W4= Region reservoirs was 809 thousand acre-feet which is 40-- ------- 105 percent of average. About 40 percent of available 20-- capacity was being used. Storage in these reservoirs at this time last year was 135 percent of average. Slanislaus Merced Kings Tuolumne San Joaquin Kern =WY2017 IIIIIIIIIIIWY2018 A 10 Yr Avg Runoff RUNOFF - Seasonal runoff of streams draining the San October 1 to date in % of average Joaquin Region totaled 735 thousand acre-feet which is 350--------- --- - - --- -- - --------- ------- - 65 percent of average. Last year, runoff for the same 300- �/7/1-- -7 -------------------- period was 340 percent of average. Seasonal runoff of 250- ------- streams draining the Tulare Lake Region area totaled 259 20 ..... ... thousand acre-feet which is 65 percent of average. Last 0- year, runoff for the same period was 230 percent of ISO- average. 50- The San Joaquin Region 60-20-20 Water Supply Index 0- is forecast to be 2.3 assuming 75 percent of median 8tanislaus Merced Kings Tula meteorological conditions. This classifies the year as "dry" Tuolumne San Joaquin Kaweah Kern WY 2017 WY 2018 in the San Joaquin according to the State Water Resources Control Board. 9 NORTH AND SOUTH U AHONTAN REGIONS Snowpack ArcUOOU|at.(]n SNOWPACK- Firstnfthnmonthnxeanurnmnnt made at 11North LshontanRegion snow courses indicate mmarea Water Content in % 0fApril lAverage wide snow water equivalent nf4.0inches. This is uso -�' '--� -'----�----------' -� '-�-� -' -' ' �� 15percent ofthe seasonal April 1average and 25 xua -!-' -- --� --------------� -�--�''�� .=c�� percent ofthe February 1average. Last year this time the mm � -' '--�---...... ..... ..... ...... pack was holding 25.4inches nfwater. At the 175 -'----'--'--'— -~ —'--- .... ..... '.... - - same time 17South LuhontmnRegion snow courses um �—' -~=�� ! ' ��, -...'................'..... ............. ---'--' - indicate ebasin-wide snow water equivalent of 125 100 | '-^' G.1inches.This ia2Dpercent nfthe seasonal Aph| 1 � - average and 3Opercent ofthe February laverage. Last sn year this time the pack was holding 30.4inches 25 ��.. ...... ....='=--^=...... '...' .... of water. - _'- Jamz mmz mar I Apr I may "-"^`-=^"-""AK�� Seaoona| pneo|pitadon (Octoberl October 1 todaie |n %*faverage through 0othe end nfJanuary) nnthe North Lmhontan 225- Region was 70 percent of normal. Precipitation last month ~^~ was about 6O percent ofthe monthly average. Season 175- precipitation at this time last year stood at 205 percent of 150- normal. Seasonal precipitation (October 1through to the � - end of January) on the South Lahmntmn Region was 40 m pencentof norma. Precipitation last month was about 95 percent ofthe monthly average. Beason precipitation at � Al this dnin last year stood at 160 percent of normal. Suprise Tahoe- Carson- Mono- Death Mojave Valley Truckee Walker Owners Valley Desert Reservoir Storage RESERVOIR STORAGE- First ofthe month storage Contents of "m 'o,nenervoiro in 9& c�ompm�|ty ' in North LaMomtan Region reservoirs was 887 thousand 100 acre-feet which isl76percent cfaverage. About O5 percent ofavailable capacity was being used. Storage in a' these reservoirs e1this time last year was 90percent of s average. First of the month storage in 8 South LaMontan Region reservoirs was 273 thousand acre-feet which in + l8Opercent ofaverage. About 85percent nfavailable capacity was being used. Storage in these reservoirs at o this time last year was lOOpercent ofaverage. 01 Truckee ast Walker Mono Basin Owens Basin WY 2017 WY 2018 &-',owAvg Runoff RUNOFF' Seasonal runoff ofstreams draining the North October todate in %ofaverage Lahmntan Region totaled 195 thousand acre-feet which in 35 136 percent of average. Last year, runoff for the same ao period was 385 percent ofaverage. Seasonal runoff of ua streams draining the South Lahontan Region area totaled ao 63thousand acre-feet which is12Opercent ofaverage. 15Last year, runoff for the same period vvon80percent of NO average. 1n 01 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 January) on the San Francisco Bay 20 __ __. __ -. - -- -- - - --- --- ---- - --- --- -- - - Region was 60 percent of normal. Precipitation last month 17 --- ---- --- - --- - -- - - was about 95 percent of the monthly average. Season 150-- - -- - - - - - - - -- - -- --- precipitation at this time last year stood at 180 percent of 12 ___ _ -_ _ __ _ _ -_ normal. Seasonal precipitation (October 1 through to the 10 - -- _- ---- - -- --- ---- end of January) on the Central Coast Region was 45 - - -- __ _ -- - - -- percent of normal. Precipitation last month was about 85 50-- _. . _ . _ __ - _ - -_ _ ___ percent of the monthly average. Season precipitation at 25-- - - - this time last year stood at 170 percent of normal. San Francisco Pajaro Salinas Santa Maria- Bay Santa Ynez ®WY 2017 _WY 2018 Reservoir Storage RESERVOIR STORAGE- First of the month storage Contents of major reservoirs in % of capacity in 17 San Francisco Region reservoirs was 397 10 --- ------- --- -- ---------------- thousand acre-feet which is 85 percent of average. About s _ __ _ _ ___ ____ 55 percent of available capacity was being used. Storage in these reservoirs at this time last year was 125 percent of 6 -- - - - -- ---- --- - average. First of the month storage in 4 Central Coast Region reservoirs was 386 thousand acre-feet which is 65 4 - -- - - _-- percent of average. About 40 percent of available capacity 2 was being used. Storage in these reservoirs at this time last year was 75 percent of average. North Bay Southeast Peninsula Salinas Santa Ynez Bay ®WY 2017 I♦WY 2018 — 10 Yr Avg Runoff RUNOFF- Seasonal runoff of streams draining the San October 1 to date in %of average Francisco Region totaled 3.4 thousand acre-feet 30 ------ ------ --- --- -------- -- --------- which is 10 percent of average. Last year, runoff 25 _ _-_ _ ..__. ..__ _ - . __ __. .. _ - . _ _ __ _- for the same period was 225 percent of average. Seasonal 20 ...... runoff of streams draining the Central Coast Region area totaled 11 thousand acre-feet million acre-feet which is 10 150-- -- --- - ---- ----- percent of average. Last year, runoff for the same period 100-- ------- --- --- was 280 percent of average. 54 Napa near Arroyo Seco Nacimiento St.Helena near Soledad ®WY 2017 _WY 2018 SOUTH COAST REGION PRECIPITATION- October through January (seasonal) precipitation on the South Coast Region was 30 percent of normal. January precipitation was 80 percent of the monthly average. Seasonal precipitation at this time last year was 190 percent of normal. Seasonal precipitation on the Colorado River-Desert Region was 35 percent of normal. Last year seasonal precipitation on the Colorado River-Desert Region was 175 percent of normal. Precipitation in January was 95 percent of average. RESERVOIR STORAGE- February 1 storage in 29 major South Coast Region reservoirs was 1.2 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 90 percent of average. On February 1 combined storage in Lakes Powell, Mead, Mohave and Havasu was about 27.1 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 65 percent of average. RUNOFF- Seasonal runoff from selected South Coast Region streams is 3 thousand acre feet which is 5 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 February 1 snowpack in the Colorado River basin above Lake Powell was 65 percent of average, highest in the Upper Green at 105 percent and lowest in the Price/San Rafel at 40 percent. 12 MAJOR WATER DISTRIBUTION PROJECTS RESERVOIR STORAGE (AVERAGES BASED ON 1966-2015 OR PERIOD RECORD) AVERAGE STORAGE AT END OF January 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 2,292 2,842 1,408 61% 40% San Luis Reservoir(SWP) 1,062 840 1,026 762 91% 72% Lake Del Valle 77 31 40 26 82% 34% Lake Silverwood 78 66 68 67 102% 86% Pyramid Lake 180 163 165 166 102% 92% Castaic Lake 325 267 260 255 95% 78% Perris Lake 131 102 50 70 69% 53% CENTRAL VALLEY PROJECT Trinity Lake 2,448 1,685 1,461 1,776 105% 73% Lake Shasta 4,552 3,034 3,546 3,349 110% 74% Whiskeytown Lake 241 205 215 205 100% 85% Folsom Lake 977 500 408 582 116% 60% New Melones Reservoir 2,400 1,414 1,013 1,981 140% 83% Millerton Lake 520 331 343 372 112% 71% San Luis Reservoir(CVP) 971 733 674 973 133% 100% COLORADO RIVER PROJECT Lake Mead 26,159 19,139 10,521 10,642 56% 41 Lake Powell 24,322 16,985 11,359 13,672 80% 56% Lake Mohave 1,810 1,674 1,712 1,641 98% 91% Lake Havasu 648 551 567 539 98% 83% EAST BAY MUNICIPAL UTILITY DISTRICT Pardee Res 204 179 204 182 102% 89% Camanche Reservoir 417 246 271 316 128% 76% East Bay (4 res.) 159 124 146 125 101% 7817c CITY AND COUNTY OF SAN FRANCISCO Hetch-Hetehy Reservoir 360 184 311 317 172% 88% Cherry Lake 268 159 228 39 24% 14% Lake Eleanor 29 11 17 10 93% 35% South Bay/Peninsula(4 res.) 238 156 178 133 85% 56% CITY OF LOS ANGELES(D.W.P) Lake Crowley t83 122 123 125 102% 68% Grant Lake 48 29 24 23 81% 49% Other Aqueduct Storage(6 res.) I I 1 1 100% 100% 13 TELEMETERED SNOW WATER EQUIVALENTS February 1,2018 INCHES OF WATER EQUIVALENT BASIN NAME APRIL 1 PERCENT 24 HRS 1 WEEK STATION NAME ELEV AVERAGE Feb 1 OF AVERAGE PREVIOUS PREVIOUS TRINITY RIVER Shimmy Lake 6400' 40.3 4.1 10.1 4.3 3.5 Crowder Flat 5100' - 0.3 - 0.4 0.4 Highland Lakes 6030' 29.9 4.2 14.0 4.2 3.2 Mumbo Basin 5650' 22.4 0.8 3.4 0.8 0.5 Bonanza King 6450' 40.5 - - - - Red Rock Mountain 6700' 39.6 11.7 29.5 11.7 9.9 Big Flat 5100' 15.8 2.3 14.4 2.3 1.6 Scott Mountain 5900' 16.0 1.0 6.0 1.0 0.7 Peterson Flat 7150' 29.2 3.6 12.4 3.6 3.0 Middle Boulder 3 6200' 28.3 2.5 8.9 2.5 2.3 SACRAMENTO RIVER Blacks Mountain 7050' 12.7 1.1 8.5 11.2 1.0 Cedar Pass 7100' 18.1 5.8 32.0 5.7 5.3 Medicine Lake 6700' 32.6 9.4 28.7 9.5 9.2 Sand Flat 6750' 42.4 4.8 11.3 4.8 4.1 Slate Creek 5700' 29.0 3.0 10.3 3.1 2.0 Adin Mountain 6200' 13.6 2.7 19.9 2.8 2.4 Stouts Meadow 5400' 36.0 3.6 10.0 3.6 2.2 Snow Mountain 5950' 27.0 5.5 20.4 5.5 3.6 FEATHER RIVER Kettle Rock 7300' 25.5 5.2 20.3 5.2 4.2 Gold Lake 6750' 36.5 7.7 21.0 7.7 7.4 Bucks Lake 5750' 44.7 3.8 8.6 3.8 2.6 Harkness Flat 6200' 28.5 4.1 14.4 4.2 3.6 Four Trees 5150' 20.0 4.3 21.6 4.6 3.1 Humbug 6500' 28.0 - - - - Grizzly Ridge 6900' 29.7 3.0 10.1 3.0 2.6 Rattlesnake 6100' 14.0 3.0 21.4 3.1 2.6 Lower Lassen Peak 8250' - 20.3 - 20,8 22.3 Pilot Peak 6800' 52.6 3.0 5.6 3.0 2.5 EEL RIVER Noel Spring 5100' - 1.0 - 1.0 0.8 YUBA&AMERICAN RIVERS Carson Pass 8353' - 10.5 10.4 9.9 Lake Lois 8600' 39.5 - - - Fomi Ridge 7600' 37.0 - Silver Lake 7100' 22.7 Blue Canyon 5280' 9.0 - - - - Schneiders 8750' 34.5 16.8 48.8 16.7 15.0 Meadow Lake 7200' 55.5 - - - - Robbs Powerhouse 5150' 5.2 1.8 35.0 1.9 1.4 Robinson Cow Camp 6480' - 5.0 - 5.0 3.9 Cent Sierra Snow Lab 6900' 33.6 5.0 14.9 4.9 3.2 Caples Lake 8000' 30.9 4.8 15.5 4.7 5.0 Alpha 7600' 35.9 3.2 8.8 3.1 1.9 Robbs Saddle 5900' 21.4 2.3 10.9 2.4 1.4 Huysink 6600' 42.6 3.0 7.0 3.0 2.2 Van Vleck 6700' 35.9 4.5 12.5 4.5 3.8 Greek Stare 5600' 21.0 3.2 15.4 3.2 2.0 MOKELUMNE&STAN ISLAUS RIVERS Highland Meadow 8700' 47.9 14.9 31.0 14.7 13.8 Gianelli Meadow 8400' 55.5 6.6 11.9 6.8 6.1 Bloods Creek 7200' 35.5 1.9 5.3 1.9 1.8 Blue Lakes 8000' 33.1 6.7 20.1 6.7 6.4 Mud Lake 7900' 44.9 - - - - Black Springs 6500' 32.0 1.8 5.6 1.8 1.4 Stanislaus Meadow 7750' 47.5 8.6 18.1 8.7 7.9 Deadman Creek 9250' 37.2 9.0 24.2 9.0 8.6 Lower Relief Valley 8100' 41.2 6.3 15.2 6.6 7.1 TUOLUMNE&MERGED RIVERS Dana Meadows 9800' 27.7 8.4 30.4 8.5 8.4 Horse Meadow 8400' 48.6 19.7 40.6 19.9 18.1 Tuolumne Meadows 8600' 22.6 6.9 30.5 6.9 7.1 Slide Canyon 9200' 41.1 14.1 34.4 14.1 13.7 Ostrander Lake 8200' 34.8 5.1 14.7 5.0 5.3 Gin Flat 7050' 34.2 1.5 4.4 1.5 1.2 Tenaya Lake 8150' 33.1 6.7 20.4 6.9 6.4 White Wolf 7900' - 4.1 - 4.2 3.4 Lower Kibble Ridge 6700' 27.4 0.2 0.6 0.4 1.0 Paradise Meadow 7650' 41.3 7.9 19.1 8.0 7.3 14 SAN JOAQUIN RIVER Volcanic Knob 10050' 30.1 6.1 20.3 6.1 5.8 Tamarack Summit 7550' 30.5 1.2 3.9 1.3 0.4 Kaiser Point 9200' 37.8 9.0 23.8 9.0 8.9 Huntington Lake 7000' 20.1 1.2 6.0 1.2 0.8 Green Mountain 7900' 30.8 3.6 11.7 3.8 3.6 Poison Ridge 6900' 28.9 1.0 3.3 1.1 1.1 Graveyard Meadow 6900' 18.8 0.5 2.6 1.0 0.4 Agnew Pass 9450' 32.3 9.0 27.7 9.2 9.4 Devils Postpile 7569' - 0.0 - 0.0 0.6 Chilkoot Meadow 7150' 38.0 1.2 3.2 1.1 1.0 KINGS RIVER Bishop Pass 11200' 34.0 3.5 10.3 3.5 3.3 Blackcap Basin 10300' 34.3 - - - Mitchell Meadow 9900' 32.9 9.8 29.7 9.8 9.0 Upper Burnt Corral 9700' 34.6 6.1 17.7 6.3 6.1 State Lakes 10300' 29.0 5.7 19.7 5.9 5.8 West Woodchuck Meadow 9100' 32.8 2.3 7.1 2.5 0.9 Big Meadows 7600' 25.9 - - - - Charlotte Lake 10400' 27.5 1.2 4,3 1.2 1.3 KAWEAH&TULE RIVERS Farewell Gap 9500' 34.5 - - - - Giant Forest 6650' 10.0 0.5 5.4 0.6 0.5 Quaking Aspen 7200' 21.0 2.9 13.9 2.9 1.7 KERN RIVER Tunnel Guard Station 8900' 15.6 - - - - Beach Meadows 7650' 11.0 0.0 0.0 0.0 0.2 Upper Tyndall Creek 11400' 27.7 2.8 10.2 2.8 2.8 Casa Vieja Meadows 8300' 20.9 3.0 14.3 3.3 2.0 Pascoes 9150' 24.9 1.7 6.7 1.7 1.6 Wet Meadows 8950' 30.3 2.7 8.9 2.8 - Chagoopa Plateau 10300' 21.8 6.7 30.8 6.7 7.5 Crabtree Meadow 10700' 19.8 - - - - SURPRISE VALLEY AREA Dismal Swamp 7050' 29.2 10.1 34.6 10.0 8.5 TRUCKEE RIVER Independence Camp 7000' 21.8 3.6 16.5 3.6 3.1 Independence lake 8450' 41.4 10.1 24.4 10.1 9.6 Squaw Valley Gold Coast 8200' 46.5 - - 18.7 13.4 Truckee 2 6400' 14.3 2.2 15.4 2.2 1.8 Independence Creek 6500' 12.7 1.3 10.2 1.3 0.2 Big Meadows 8700' 25.7 9.6 37.4 9.4 8.6 LAKE TAHOE BASIN Rubicon Peak 2 7500' 29.1 2.2 7.6 2.2 2.0 Tahoe City Cross 6750' 16.0 1.4 8.8 1.6 1.4 Echo Peak 5 7800' 39.5 9.4 23.8 9.2 8.7 Hagans Meadow 8000' 16.5 1.3 7.9 1.3 1.2 Fallen Leaf Lake 6250' 7.0 1.0 14.3 0.9 0.$ Ward Creek 3 6750' 39.4 7.5 19.0 7.5 7.3 Mount Rose Ski Area 8900' 38.5 16.0 41.6 16.0 15.5 Heavenly Valley 8800' 28.1 10.4 37.0 10.4 9.9 Marlette Lake 8000' 21.1 3.3 15.6 2.9 4.0 CARSON RIVER Spratt Creek 6150' 4.5 0.5 11.1 0.8 0.8 Horse Meadow 8400' 48.6 19.7 40.6 19.9 18.1 Burnside Lake 8129' - 7.0 7.0 6.1 Monitor Pass 8350' - 4.0 4.0 3.9 Poison Flat 7900' 16.2 2.5 15.4 2.5 2.7 FOrestdale Creek 8017' - 10.9 - 10.6 8.8 Ebbetts Pass 8700' 38.8 - - - 7.8 WALKER RIVER Sonora Pass Bridge 8750' 26.0 3.5 13.5 3.5 3.2 Virginia Lakes Ridge 9300' 20.3 4.1 20.2 4.0 3.6 Lobdell Lake 9200' 17.3 4.8 27.7 5.0 4.8 Summit Meadow 9313' - 5.5 - 5.5 5.4 Leavitt Meadows 7200' 8.0 0.0 0.0 0.1 0.5 Leavitt Lake 9600' - 18.9 - 18.9 18.6 OWENS RIVER/MONO LAKE Cottonwood Lakes 10150' 11.6 4.6 39.5 4.7 3.5 Gem Pass 10750' 31.7 7.1 22.4 7.1 7.2 Rock Creek Lakes 9700' 14.0 1.3 9.0 1.2 1.0 South Lake 9600' 16.0 3.1 19.5 3.0 3.0 Big Pine Creek 9800' 17.9 2.3 13.1 2.4 2.2 Sawmill 10200' 19.4 3.6 18.4 3.7 3.4 NORMAL SNOWPACK ACCUMULATION EXPRESSED AS A PERCENT OF APRIL IST 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 February 1 Statewide Conditions Department of Water Resources 250 - -California Cooperative Snow-Surveys _ -_- 215 200 -- 18.._ a> 3'B — -- CO / Q150 ---- 1.."—.............--..........—.------13.535. .—- — — —— — ... ... ..........., 130 110 17 14 j 24 11515 v 100 f. 94 �� --- — /95... f ........-- f80so 5555 % 65 60 / 5 64 50 40/ —_. 5 3_Z44 .. — A—; 55. 1q�15 2 o 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 Snowpack ate. - 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/201-8 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 runoff, water management, water supply forecasting, and modeling and climatology of snow. Thursday will include a technical tour of the nearby Rio Grande Valley. Depicted on this month's cover is a view from the Tioga Road bridge looking out at Tuolumne Meadows taken on June 6, 2017. 16 9EN' OSP 18 144626 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 I ifi -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 HydrQlogic 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 Sacramento, CA 94236-0001 SACRAMENTO CA PERMIT NO 424 BUTTE COUNTY ADMINISTRATION FEB 2 6 2018 OROVIUF,CALIFORNIA BUTTE COUNTY CHAIRMAN-'BD OF SUPERVISORS 25 COUNTY CENTER DR OROVILLE CA 95965-3316 yrst Class S�A�•�� rH �P 'g11PEl(A'' Fs (7 r � cgLIFOR��A