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Water Tracker

A monthly assessment of trends in water supply
and use for Santa Clara County, California

 

As of August 1, 2014

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District reservoir levels are continuing to fall and creeks are continuing to dry back through the summer months. Releases from Lexington Reservoir have been reduced in an effort to maintain flows in at least a portion of the creek until the end of the year. Chesbro Reservoir is at 2.8 percent of capacity and releases from the reservoir will end by September. Due to reduced groundwater recharge and increased pumping, groundwater levels are continuing to drop. Some water from the Semitropic Groundwater Bank is expected to be available in the fall and winter months, and this will help maintain local groundwater reserves for 2015. Cumulative 2014 water savings through May are estimated at 12%, compared to 2013 usage, which is below the 20% water use reduction target set by the Board in February. On July 22, 2014, the Board approved additional resources to assist retail water agencies with implementation of new State Water Resources Control Board emergency regulations that went into effect at the end of July requiring mandatory landscape restrictions. 

 

 
 


Weather

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Rainfall in Santa Clara County:

  • Month of July = 0.0 inches
  • The average daily high temperature for July was 81 degrees Fahrenheit.  Temperatures were slightly below normal for the month

      

       
 


Local Reservoirs

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  • Total August 1 storage = 73,079 acre-feet*
    (Click here for current local reservoir storage)
    • 69% of 20-year average for this date
    • 43% of total capacity
    • 59% of restricted capacity storage
      (169,009 acre-feet total storage capacity limited by seismic restrictions to 122,924 acre-feet)
  • Lowest storage levels are in Chesbro, Uvas, Guadalupe, and Stevens Creek reservoirs at 3%, 8%, 9%, and 11% of their total capacities, respectively

      *Total includes over 44% imported water, including 90 acre-feet stored in July

       
 


Imported water 

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  • 2014 State Water Project (SWP) and Central Valley Project (CVP) allocations:
    • SWP allocation:  5% = 5,000 acre-feet (20% of allocation [1,000 acre-feet] may be delivered in summer, 80% after September 1) 
    • CVP allocations:  50% for Municipal and Industrial uses and Zero% for Irrigation for a total of 65,000 acre-feet  
  • 2013 SWP and CVP estimated carryover supplies to 2014:  31,227 acre-feet
  • Reservoir storage (map) (table), as of August 1, 2014:
    • Shasta Reservoir at 35% of capacity (49% of average for this date)
    • Oroville Reservoir at 35% of capacity (49% of average for this date)
    • San Luis Reservoir at 22% of capacity (46% of average for this date)
  • Daily reservoir storage summary (map) (table), current
  • Semitropic groundwater bank reserves:  262,665 acre-feet at start of year.  Withdrawal of banked reserves may be limited by SWP operational constraints, with the available quantity to be determined; California Aqueduct Reverse Flow Project initiated to expand exchange potential with the CVP
  •  Hetch Hetchy No imported water management agreements executed in July
  • Estimated Hetch Hetchy deliveries to Santa Clara County (click to enlarge graph at right):
    • Month of July  = 4,800 acre-feet
    • 2014 Total = 26,500 acre-feet, or 96% of the five-year average
    • 2014 preliminary reduction = 10% announced by SFPUC on January 31
       
 


Groundwater

 

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Groundwater storage:  Total storage at the end of 2014 is projected to fall within Stage 3 (Severe) of the Water Shortage Contingency Plan.  If the 20% water use reduction target set by the Board on February 25 is achieved, 2014 end of year storage is projected to be within range of Stage 2 (Alert).


Santa Clara Plain

Coyote Valley

Llagas Subbasin

Santa Clara Plain
- The July managed recharge estimate is 680 acre-feet. The year-to-date managed recharge estimate is 9,300 acre-feet or 29% of the five-year average

- The July groundwater pumping estimate is 11,400 acre-feet. The year-to-date groundwater pumping estimate is 65,500 or 139% of the five-year average

- The groundwater level in Santa Clara Plain (San Jose) is about 29 feet lower than last year and about 39 feet lower than the five-year average

Coyote Valley
- The July managed recharge estimate is 550 acre-feet. The year-to-date managed recharge estimate is 4,300 acre-feet, or 60% of the five-year average

- The July groundwater pumping estimate is 870 acre-feet. The year-to-date groundwater pumping estimate is 5,400 acre-feet, or 79% of the five-year average 

- The groundwater level in Coyote Valley is about four feet lower than last year and nine feet lower than the five-year average
Llagas Subbasin
- The July managed recharge estimate is 530 acre-feet. The year-to-date managed recharge estimate is 5,000 acre-feet, or 35% of the five-year average 

- The July groundwater pumping estimate is 4,100 acre-feet. The year-to-date groundwater pumping estimate is 22,300 acre-feet, or 101% of the five-year average 

- The groundwater level in Llagas Subbasin (San Martin) is about 22 feet lower than last year and 32 feet lower than the five-year average

       
 

Treated water 

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  •   Treated Water Delivered  Below average demands of 10,347 acre-feet delivered in July
  • This total is 76% of the five-year average for July
  • Estimated year-to-date = 54,600 acre-feet, which is 81% of the five-year average
       
 

 
Conserved water

 

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  • /uploadedImages/Services/CleanReliableWater/WaterSupplyPlanning/WaterTracker_documents_and_images/1-Final_Docs_and_Images/11.Aug_2013_Total-Water-Use.jpgSaved 56,000 acre-feet in FY13 from long-term program (baseline year is 1992)
  • Long-term program goal is to save nearly 60,000 acre-feet in FY14
  • Based on the District's Water Shortage Contingency Plan, the Board set a 2014 water use reduction target of 20%, in addition to long-term program savings
  • Currently achieving a 12% reduction compared to 2013 (through May 2014)
       
 


Recycled
water

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  •   Recycled WaterEstimated July 2014 production  =  2,695 acre-feet (billed semi-annually)
  • Estimated year-to-date = 12,714 acre-feet or 139% of the five-year average
  • Silicon Valley Advanced Water Purification Center was completed and began delivery of high quality treated recycled water for blending with existing nonpotable water on March 25, 2014