Executive Update: Hydrologic Conditions in California

Executive Update

Hydrologic Conditions in California (07/31/2016)

Northern Sierra Precipitation Accumulation (1)
Rainfall & Snow Water Content (in inches)
 
Water Year Amount to Date (since Oct. 1, 2015): 57.80      
Average to Date: 48.80      
Percent of Average to Date: 118 %  
Average for the Water Year (Oct. 1 through Sep. 30) 50.00      
Percent of Average for the Water Year (Oct. 1 through Sep. 30) 116 %  

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


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

Forecast of Regional Water Supply Indices (2)
Index Value Year Type
8 River Index for July (in 1000 AF)545       n/a
Sacramento Valley Water Year Type Index (40-30-30) @ 50%7.1       Below Normal
Sacramento Valley Water Year Type Index (40-30-30) @ 90%6.8       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 07/31/2016 midnight
Reservoir River Storage
(in 1000 AF)
Avg Storage
(in 1000 AF)
%
Average
Capacity
(in 1000 AF)
%
Capacity
Flood Control (3)
Encroachment
(in 1000 AF)
Trinity Lake Trinity 1,151   1,954   59   2,448   47   ---      
Shasta Lake Sacramento 3,544   3,234   110   4,552   78   -1,008      
Lake Oroville Feather 2,334   2,579   90   3,538   66   -1,204      
New Bullards Bar Res Yuba 740   750   99   966   77   -226      
Folsom Lake American 485   691   70   977   50   -492      
New Melones Res Stanislaus 583   1,467   40   2,400   24   -1,837      
Don Pedro Res Tuolumne 1,460   1,548   94   2,030   72   -570      
Lake McClure Merced 516   627   82   1,025   50   -508      
Millerton Lake San Joaquin 353   327   108   520   68   -168      
Pine Flat Res Kings 328   509   65   1,000   33   -672      
Isabella Kern 134   274   49   568   24   -227      
San Luis Res (Offstream) 195   996   20   2,041   10   ---      

(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 07/31/2016

Station
Oct 1 to Date
2015 - 2016
%
Average
Season to Date
2014 - 2015
%
Average
% Average
Oct 1 - Sep 30
Mount Shasta40.939635.098294
Eureka43.9711230.0976109
Redding37.3011023.1268108
South Lake Tahoe22.0911513.8172108
Sacramento Executive Airport16.148915.438587
Santa Rosa (Sonoma Co AP)30.438522.326284
San Francisco22.149517.647594
Stockton16.6012110.6778118
Yosemite36.079718.405095
Monterey21.5413614.5792134
Paso Robles7.37598.406758
Fresno14.331276.5057125
Bakersfield5.44865.298384
Death Valley1.68831.055271
Los Angeles6.35438.675943
Riverside5.17435.814842
Palm Springs2.50502.505044
San Diego7.737610.029975
Updated Information and Data
Daily Drought Information Summary
Daily Statewide Hydrologic Update(Interactive)
Weekly Update to Unimpaired Runoff Forecast (Feb - Jun)
Unimpaired Forecast Discussion (Weekly/Monthly, Dec - June)
Bulletin 120, Water Conditions in California (Monthly, Feb - May)
Comments
 
Statewide Hydrologic Conditions (As of July 31)
As of July 31, statewide hydrologic conditions were as follows: precipitation, 110 percent of average to date; runoff, 95 percent of average to date; and reservoir storage, 85 percent of average for the date.
 
Sacramento River Unimpaired Runoff
Sacramento River Region unimpaired runoff, for Water Year 2016, observed through July 31, 2016 was about 16.8 million acre-feet (MAF), which is about 96 percent of average. In comparison to Water Year 2015, the observed Sacramento River Region unimpaired runoff through July 31, 2015 was about 8.7 MAF, or about 50 percent of average.
 
Northern Sierra 8-Station Precipitation Index
On July 31, the Northern Sierra 8-Station Precipitation Index Water Year total was 57.8 inches, which is about 118 percent of the seasonal average to date and 116 percent of an average water year (50.0 inches). During July, the total precipitation for the 8-Stations was 0.0 inches. Last year on July 31, the Water Year 2015 seasonal total for the 8-Stations was 36.7 inches, or about 75 percent of average.
 
San Joaquin 5-Station Precipitation Index
On July 31, the San Joaquin 5-Station Precipitation Index Water Year total was 40.0 inches, which is about 100 percent of the seasonal average to date and 98 percent of an average water year (40.8 inches). During July, the total precipitation for the 5-Stations was 0.0 inches. Last year on July 31, the Water Year 2015 seasonal total for the 5-Stations was 18.8 inches, or about 47 percent of average.
 
Tulare Basin 6-Station Precipitation Index
On July 31, the Tulare Basin 6-Station Precipitation Index Water Year total was 25.7 inches, which is about 90 percent of the seasonal average to date and 88 percent of an average water year (29.3 inches). During July, the total precipitation for the 6-Stations was 0.0 inches. Last year on July 31, the Water Year 2015 seasonal total for the 6-Stations was 13.4 inches, or about 47 percent of average.
 
Long-Range Weather Forecast
The latest National Weather Service Climate Prediction Center (CPC) long-range, 1-month precipitation outlook for August 2016, issued July 31, 2016, suggests average precipitation for all of California, except for the northeast corner of the State where below average precipitation is indicated.
 
Next Update
Updates to the Executive Summary will generally be issued 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 Thursday, September 15, 2016, for conditions on August 31, unless there are significant hydrologic changes.

Report name: