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Water Tracker

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

 

As of July 1, 2014

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The rainfall year ended June 30th, and it was preliminarily the second driest rainfall year on record at the San Jose gauge. According to the U.S. Drought Monitor, Santa Clara County is in the highest drought intensity category: D4 – Exceptional Drought. Last year at this time, Santa Clara County was only in the D2 – Severe Drought intensity category. Local watersheds are very dry and reservoirs levels are dropping, except for Anderson and Calero Reservoirs which have been filled with imported water to meet summer demands. Chesbro Reservoir storage is currently at less than 5% of its capacity. Due to the lack of groundwater recharge and increased pumping from the drought, groundwater levels are dropping. Based on the District’s Water Shortage Contingency Plan, the Board set a 20% water use reduction target to ensure adequate groundwater reserves for 2015. Cumulative 2014 water savings through April are estimated at 13%, compared to 2013 usage.

 

 
 


Weather

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Rainfall in Santa Clara County:

  • Month of June = 0.0 inches
  • Total-to-date = 6.10 inches or 42% of average to date (Rainfall year is July 1 to June 30)

      

       
 


Local Reservoirs

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  • Total July 1 storage = 78,981 acre-feet*
    (Click here for current local reservoir storage)
    • 70% of 20-year average for this date
    • 47% of total capacity
    • 64% of restricted capacity storage
      (169,009 acre-feet total storage capacity limited by seismic restrictions to 122,924 acre-feet)
  • Low storage levels are in Chesbro, Guadalupe, Uvas, and Stevens Creek reservoirs at 5%, 10%, 10%, and 12% of their total capacity, respectively

      *Total includes over 40% imported water, including 500 acre-feet stored in June

       
 


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 July 1, 2014:
    • Shasta Reservoir at 41% of capacity (51% of average for this date)
    • Oroville Reservoir at 43% of capacity (52% of average for this date)
    • San Luis Reservoir at 32% of capacity (51% 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
  •  Hetch Hetchy No imported water management agreements executed in June; continuing to pursue several potential agreements
  • Estimated Hetch Hetchy deliveries to Santa Clara County (click to enlarge graph at right):
    • Month of June  = 4,800 acre-feet
    • 2014 Total = 21,200 acre-feet, or 97% 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, expected 2014 end of year storage will be within the range of Stage 2 (Alert).


Santa Clara Plain

Coyote Valley

Llagas Subbasin

Santa Clara Plain
- The June managed recharge estimate is 600 acre-feet. The year-to-date managed recharge estimate is 8,500 acre-feet or 32% of the five-year average

- The June groundwater pumping estimate is 10,600 acre-feet. The year-to-date groundwater pumping estimate is 51,700 or 141% of the five-year average

- The groundwater level in Santa Clara Plain (San Jose) is about 32 feet lower than last year and about 34 feet lower than the five-year average

Coyote Valley
- The June managed recharge estimate is 530 acre-feet. The year-to-date managed recharge estimate is 3,800 acre-feet, or 65% of the five-year average

- The June groundwater pumping estimate is 740 acre-feet. The year-to-date groundwater pumping estimate is 4,400 acre-feet, or 80% 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 June managed recharge estimate is 510 acre-feet. The year-to-date managed recharge estimate is 4,400 acre-feet, or 37% of the five-year average 

- The June groundwater pumping estimate is 3,500 acre-feet. The year-to-date groundwater pumping estimate is 18,600 acre-feet, or 113% 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 10,000 acre-feet delivered in June
  • This total is 79% of the five-year average for June
  • Estimated year-to-date = 44,300 acre-feet, which is 82% 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 13% reduction compared to 2013 (through April 2014)
       
 


Recycled
water

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  •   Recycled WaterEstimated June 2014 production  =  2,539 acre-feet (billed semi-annually)
  • Estimated year-to-date = 10,097 acre-feet or 146% 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