Executive Update: Hydrologic Conditions in California

Executive Update

Hydrologic Conditions in California (04/01/2016)

Northern Sierra Precipitation Accumulation (1)
Rainfall & Snow Water Content (in inches)
 
Water Year Amount to Date (since Oct. 1, 2015): 51.92      
Average to Date: 41.60      
Percent of Average to Date: 125 %  
Average for the Water Year (Oct. 1 through Sep. 30) 50.00      
Percent of Average for the Water Year (Oct. 1 through Sep. 30) 104 %  

(1) Northern Sierra (Sacramento, Feather, Yuba, and American River Basins)

Snowpack Water Content
Region
Water Content
(in inches)
%
Avg to Date
%
April 1 Avg (2)
Northern Sierra 27.90                   97                   97                  
Central Sierra 25.30                   88                   88                  
Southern Sierra 19.10                   71                   71                  
Statewide 24.20                   86                   86                  

(2) April 1 is the date of normal maximum accumulation for the season.

Forecast of Regional Water Supply Indices (3)
Index Value Year Type
8 River Index for March (in 1000 AF)6,510       n/a
Sacramento Valley Water Year Type Index (40-30-30) @ 50%7.3       Below Normal
Sacramento Valley Water Year Type Index (40-30-30) @ 90%6.7       Below Normal
San Joaquin Valley Water Year Type Index (60-20-20) @ 50%2.5       Dry
San Joaquin Valley Water Year Type Index (60-20-20) @ 75%2.4       Dry

(3) For more information see Sacramento & San Joaquin Valley Water Year Type Index forecast: Latest | Previous
    (Issued monthly from December 1 through May 1)

Key Reservoir Storage As of 03/31/2016 midnight
Reservoir River Storage
(in 1000 AF)
Avg Storage
(in 1000 AF)
%
Average
Capacity
(in 1000 AF)
%
Capacity
Flood Control (4)
Encroachment
(in 1000 AF)
Trinity Lake Trinity 1,280   1,927   66   2,448   52   ---      
Shasta Lake Sacramento 4,027   3,691   109   4,552   88   258      
Lake Oroville Feather 3,060   2,696   114   3,538   86   183      
New Bullards Bar Res Yuba 816   701   116   966   84   17      
Folsom Lake American 691   628   110   977   71   52      
New Melones Res Stanislaus 617   1,510   41   2,400   26   -1,428      
Don Pedro Res Tuolumne 1,218   1,483   82   2,030   60   -472      
Lake McClure Merced 338   565   60   1,025   33   -379      
Millerton Lake San Joaquin 345   366   94   520   66   -175      
Pine Flat Res Kings 387   564   69   1,000   39   -399      
Isabella Kern 61   201   30   568   11   -301      
San Luis Res (Offstream) 1,059   1,846   57   2,041   52   ---      

(4) Temporary encroachment into seasonally reserved flood storage space; requirements can vary considerably on a daily basis due to numerous variables: rainfall amounts, anticipated snowmelt, time of year, soil moisture, etc.

Daily Precipitation (in inches) for Selected Stations as of 04/01/2016

Station
Oct 1 to Date
2015 - 2016
%
Average
Season to Date
2014 - 2015
%
Average
% Average
Oct 1 - Sep 30
Mount Shasta35.509930.588681
Eureka41.0312327.2982102
Redding31.8511120.997392
South Lake Tahoe17.681108.295187
Sacramento Executive Airport14.729113.458379
Santa Rosa (Sonoma Co AP)28.658920.846579
San Francisco20.519716.047687
Stockton13.421109.457895
Yosemite32.3210211.393685
Monterey20.6414613.3294128
Paso Robles7.21637.706756
Fresno12.871324.6047112
Bakersfield3.91704.538160
Death Valley1.28731.056054
Los Angeles6.06457.335541
Riverside4.67433.853638
Palm Springs2.45552.074643
San Diego6.84756.517166
Comments
*********FOR UPDATED INFORMATION AND DATA GO TO******* Daily Drought Information Summary: http://cdec.water.ca.gov/cgi-progs/reports/DROUGHTSUM; Daily Statewide Hydrologic Update (Interactive): http://cdec.water.ca.gov/floodER/hydro/; Weekly Update to Unimpaired Runoff Forecast (Feb- Jun): http://cdec.water.ca.gov/cgi-progs/iodir/B120UP, http://cdec.water.ca.gov/cgi-progs/products/WSFCastDiscussion.pdf ************************************************* As of March 31, statewide hydrologic conditions were as follows: precipitation, 110 percent of average to date; snow water content, 85 percent of average to date (85 percent of the April 1 average); runoff, 115 percent of average to date; and reservoir storage, 85 percent of average for the date. Sacramento River Region unimpaired runoff, for Water Year 2016, observed through March 31, 2016 was about 12.2 million acre-feet (MAF), which is about 111 percent of average. In comparison to Water Year 2015, the observed Sacramento River Region unimpaired runoff through March 31, 2015 was about 6.9 MAF, or about 63 percent of average. On March 31, the Northern Sierra 8-Station Precipitation Index Water Year total was 51.9 inches, which is about 125 percent of the seasonal average to date and 104 percent of an average water year (50.0 inches). During March, the total precipitation for the 8-Stations was 16.4 inches, or about 238 percent of average for the month. Last year on March 31, the Water Year 2015 seasonal total for the 8-Stations was 31.7 inches, or about 76 percent of average. On March 31, the San Joaquin 5-Station Precipitation Index Water Year total was 35.8 inches, which is about 107 percent of the seasonal average to date and 88 percent of an average water year (40.8 inches). During March, the total precipitation for the 5-Stations was 8.7 inches, or about 143 percent of average for the month. Last year on March 31, the Water Year 2015 seasonal total for the 5-Stations was 13.7 inches, or about 41 percent of average. The latest National Weather Service Climate Prediction Center (CPC) long-range, 1-month precipitation outlook for April 2016, issued March 31, 2016, suggests above-normal precipitation for all of California, except the southern fourth of the State where normal precipitation is indicated. Updates to the Executive Summary will generally be issued approximately monthly (depending on conditions) through the wet months of winter and spring. Beginning about June 1, this product is updated monthly through the dry seasons of summer and fall. The next update of this product will be issued about Friday, May 13, 2016, for conditions on May 1, unless there are significant hydrologic changes.


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