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Water Tracker

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


As of January 1, 2015

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Cumulative 2014 water savings in the County from February 2014 to November 2014 is estimated at 13%, which is less than the 20% target called by the Board. We started 2014 with approximately 339,000 acre-feet of groundwater storage. Due to the lack of surface water in 2014 and increased groundwater pumping, it is estimated that we used 85,000 acre-feet from our groundwater storage reserve, causing our current storage level to drop to approximately 254,000 acre-feet. To get the groundwater storage level back to above 300,000 acre-feet, which is considered the normal range, water use reductions are continuing in 2015. Although we have received above average rainfall to date, our local reservoir storage and the Northern Sierra snowpack are still below average. The drought is continuing and it will take time to recover even if we receive exceptional rainfall.




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Rainfall in Santa Clara County:

  • Month of December = 7.48 inches
  • Total to date = 9.92 inches or 187% of average to date (rainfall year is July 1 to June 30); January 2 Northern Sierra snowpack water content is about 53% of average for that date



Local Reservoirs

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  • Total January 1 storage = 67,961 acre-feet
    (Click here for current local reservoir storage)
    • 83% of 20-year average for that date
    • 40% of total capacity
    • 55% of restricted capacity storage
      (169,009 acre-feet total storage capacity limited by seismic restrictions to 122,924 acre-feet)
  • Approximately 32,200 acre-feet of Imported Water delivered into local reservoirs during the 2014 calendar year

Imported water 

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  • 2015 State Water Project (SWP) and Central Valley Project (CVP) allocations:
    • Initial 2015 SWP allocation:  10% = 10,000 acre-feet
    • Initial 2015 CVP allocations expected to be announced in mid-February
  • 2014 SWP and Central Valley Project (CVP) allocations: = 70,000 acre-feet
    • SWP allocation:  5% = 5,000 acre-feet 
    • CVP allocations:  50% for Municipal and Industrial uses and Zero% for Irrigation for a total of 65,000 acre-feet  
  • Reservoir storage (map) (table), as of January 1, 2015:
    • Shasta Reservoir at 41% of capacity (66% of average for this date)
    • Oroville Reservoir at 38% of capacity (62% of average for this date)
    • San Luis Reservoir at 40% of capacity (59% of average for this date)
  • Daily reservoir storage summary (map) (table), current
  • District Semitropic groundwater bank reserves:  262,665 acre-feet at start of 2014 (75% of capacity).  An estimated 35,000 acre-feet was withdrawn from Semitropic in 2014; although District did not have to implement California Aqueduct Reverse Flow Project in 2014, if drought continues, District may need to implement and/or expand reverse flow project to retrieve its previously-stored water supplies from Semitropic in 2015
  • Board Governance Policy No. EL-7.3 includes keeping the Board informed of imported water management activities on an ongoing basis.  In FY15, four imported water management agreements were executed as of January 1; staff continuing to pursue several potential agreements
  • Hetch Hetchy deliveriesEstimated Hetch Hetchy deliveries to Santa Clara County (click to enlarge graph at right):
    • Month of December  = 3,100 acre-feet
    • 2014 Total = 46,700 acre-feet, or 90% of the five-year average
    • 2014 reduction = 17% cumulative through November 2014, included in above County total of 13%



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Groundwater storage:  Total storage at the end of 2014 is estimated to fall within Stage 2 (Alert) of the Water Shortage Contingency Plan.

Santa Clara Plain

Coyote Valley

Llagas Subbasin

Santa Clara Plain
- The December managed recharge estimate is 340 acre-feet. The 2014 managed recharge estimate is 10,900 acre-feet or 18% of the five-year average

- The December groundwater pumping estimate is 8,100 acre-feet. The 2014 groundwater pumping estimate is 116,400 or 137% of the five-year average

- The groundwater level in Santa Clara Plain (San Jose) is about 30 feet lower than December last year and about 45 feet lower than the five-year average

Coyote Valley
- The December managed recharge estimate is 550 acre-feet. The 2014 managed recharge estimate is 7,000 acre-feet, or 54% of the five-year average

- The December groundwater pumping estimate is 750 acre-feet. The 2014 groundwater pumping estimate is 10,200 acre-feet, or 85% of the five-year average 

- The groundwater level in Coyote Valley is about four feet lower than December last year and six feet lower than the five-year average
Llagas Subbasin
- The December managed recharge estimate is 500 acre-feet. The 2014 managed recharge estimate is 7,900 acre-feet, or 31% of the five-year average 

- The December groundwater pumping estimate is 3,200 acre-feet. The 2014 groundwater pumping estimate is 42,600 acre-feet, or 100% of the five-year average 

- The groundwater level in Llagas Subbasin (San Martin) is about 16 feet lower than December last year and 30 feet lower than the five-year average


Treated water 

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  • Treated Water DeliveredBelow average demands of 4,046 acre-feet delivered in December
  • This total is 59% of the five-year average for December
  • Estimated year-to-date = 91,500 acre-feet or 76% 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 59,300 acre-feet in FY14 from long-term program (baseline year is 1992)
  • Long-term program goal is to save nearly 63,000 acre-feet in FY15
  • Based on the District's Water Shortage Contingency Plan, the Board has extended the call for a 20% reduction through June 30, 2015
  • Currently achieving a 13% reduction compared to 2013 (through November 2014)


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  • Recycled WaterEstimated December 2014 production  =  1,275 acre-feet (billed semi-annually)
  • Estimated 2014 = 22,054 acre-feet or 134% of the five-year average
  • Silicon Valley Advanced Water Purification Center produced 1,413 million gallons of advanced purified recycled water since March 25, 2014.  The purified water is blended with existing tertiary recycled water for South Bay Water Recycling Program's customer