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Water Tracker

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


As of December 1, 2014

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Cumulative 2014 water savings by customers from February to October is estimated at 12%, which is less than the 20% target called by the Board.  As we are using our groundwater reserves to make it though the drought, it will take time to replenish them.  To get groundwater levels back to normal, water use reductions will need to continue in 2015 even if we experience average winter rains.  Although we received some rain in November, which is a good start, we still need considerably more rain to see appreciable inflow into the reservoirs as the upper watersheds are so dry.  On Tuesday, November 25, the Santa Clara Valley Water District Board unanimously passed a resolution extending its call for a countywide reduction of water use by 20 percent compared to 2013 water use until June 30, 2015.  Further, the board approved budget adjustments of $3.8 million to extend augmented water conservation programs and outreach campaigns.  On December 1, the State Water Project issued an initial 2015 allocation of 10% of contractual water amounts.




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Rainfall in Santa Clara County:

  • Month of November = 1.53 inches
  • Total to date = 2.44 inches or 92% of average to date (rainfall year is July 1 to June 30)



Local Reservoirs

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  • Total December 1 storage = 48,334 acre-feet
    (Click here for current local reservoir storage)
    • 63% of 20-year average for this date
    • 29% of total capacity
    • 39% 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 Uvas, Guadalupe, and Stevens Creek reservoirs at 2%, 4%, and 5% of their total capacities, respectively.  The level in Chesbro reservoir is below the District's measuring gauge
  • Approximately 32,200 acre-feet of Imported Water delivered into local reservoirs this year

Imported water 

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  • Initial 2015 State Water Project (SWP) allocation:  10% = 10,000 acre-feet (Press Release) (Notice to Contractors)
  • 2014 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 December 1, 2014:
    • Shasta Reservoir at 23% of capacity (39% of average for this date)
    • Oroville Reservoir at 26% of capacity (43% of average for this date)
    • San Luis Reservoir at 24% of capacity (40% 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 originally anticipated to be limited by SWP operational constraints, so California Aqueduct Reverse Flow Project initiated to expand exchange potential with the CVP; District has been informed by California Department of Water Resources that there is sufficient exchange capacity and operational flexibility in the SWP system to support the exchange necessary for the District to retrieve its previously-stored water supplies (currently estimated at about 35,000 acre-feet) from Semitropic in 2014; District will not be implementing the reverse flow project in 2014
  • Board Governance Policy No. EL-7.3 includes keeping the Board informed of imported water management activities on an ongoing basis.  No imported water management agreements were executed as of December 1; continuing to pursue several potential agreements
  • Estimated Hetch Hetchy deliveries to Santa Clara County (click to enlarge graph at right):
    • Month of November  = 3,700 acre-feet
    • 2014 Total = 44,300 acre-feet, or 92% of the five-year average
    • 2014 preliminary reduction = 10% voluntary announced by SFPUC on January 31



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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 November managed recharge estimate is 420 acre-feet. The year-to-date managed recharge estimate is 10,700 acre-feet or 20% of the five-year average

- The November groundwater pumping estimate is 8,700 acre-feet. The year-to-date groundwater pumping estimate is 109,200 or 137% of the five-year average

- The groundwater level in Santa Clara Plain (San Jose) is about 30 feet lower than November last year and about 42 feet lower than the five-year average

Coyote Valley
- The November managed recharge estimate is 550 acre-feet. The year-to-date managed recharge estimate is 6,500 acre-feet, or 53% of the five-year average

- The November groundwater pumping estimate is 880 acre-feet. The year-to-date groundwater pumping estimate is 9,600 acre-feet, or 86% of the five-year average 

- The groundwater level in Coyote Valley is about nine feet lower than November last year and 11 feet lower than the five-year average
Llagas Subbasin
- The November managed recharge estimate is 530 acre-feet. The year-to-date managed recharge estimate is 7,400 acre-feet, or 31% of the five-year average 

- The November groundwater pumping estimate is 3,400 acre-feet. The year-to-date groundwater pumping estimate is 38,900 acre-feet, or 98% of the five-year average 

- The groundwater level in Llagas Subbasin (San Martin) is about 23 feet lower than November last year and 37 feet lower than the five-year average


Treated water 

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  •   Treated Water Delivered  Below average demands of 5,954 acre-feet delivered in November
  • This total is 72% of the five-year average for November
  • Estimated year-to-date = 87,600 acre-feet, which is 77% 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 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 October 2014)


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  •   Recycled WaterEstimated October 2014 production  =  1,408 acre-feet (billed semi-annually)
  • Estimated year-to-date = 20,779 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