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Water Tracker

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

 

As of April 1, 2014

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Despite some precipitation in March, severe drought conditions continue throughout California. With very little local watershed runoff, many of the district’s 10 reservoirs are at less than 35% of their 20-year average storage. Imported water is currently being pumped into Anderson Reservoir to ensure adequate treatment plant supplies this summer. Both the federal Central Valley Project and State Water Project continue to face regulatory and water quality challenges due to limited Central Valley runoff, and this will continue to affect imported water deliveries to the county in coming months. District groundwater recharge in 2014 is projected to be about 25% of normal recharge, and groundwater levels are projected to drop through the end of the year. On February 25, the Board passed a resolution calling for retail water agencies, municipalities, and the county to implement mandatory measures as needed to reach a 20% water use reduction target in 2014. Achieving the 20% target will avoid groundwater dropping to the “Severe” range and ensure adequate reserves for 2015.

 

 
 


Weather

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Rainfall in Santa Clara County:

  • Month of March = 1.34 inches
  • Total-to-date = 5.43 inches or 43% of average to date (Rainfall year is July 1 to June 30)April 1 Northern Sierra snowpack water content is about 23% of average for this date
       
 


Local Reservoirs

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  • Total April 1 storage = 70,832 acre-feet
    (Click here for current local reservoir storage)
    • 57% of 20-year average for this date
    • 42% of total capacity
    • 58% 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 10%, 11%, 11%, and 13% of their total capacity, respectively
  • Approximately 11,400 acre-feet of Imported Water delivered into local reservoirs during March 2014
       
 


Imported water 

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  • 2014 State Water Project and Central Valley Project allocations:
    • State Water Project allocation:  Zero% = 0 acre-feet (no change in March) 
    • Central Valley Project allocations:  50% for Municipal and Industrial uses and Zero% for Irrigation, for an approximate total of 65,000 acre-feet  
  • 2013 State Water Project and Central Valley Project estimated carryover supplies available for 2014:  currently estimated at 27,380 acre-feet
  • Reservoir storage (map) (table), as of April 1, 2014:
    • Shasta Reservoir at 48% of capacity (60% of average for this date)
    • Oroville Reservoir at 49% of capacity (64% of average for this date)
    • San Luis Reservoir at 42% of capacity (46% of average for this date)
  • Daily reservoir storage summary (map) (table), current
  • Semitropic groundwater bank reserves:  approximately 262,665 acre-feet as of April 1.  Withdrawal of banked reserves may be limited by SWP operational constraints, with the available quantity to be determined
  •  Hetch Hetchy Exchanges and transfers in FY14:  availability of transfer supplies in 2014 is limited due to statewide critically dry conditions and operational constraints, quantity to be determined
  • Estimated Hetch Hetchy deliveries to Santa Clara County (click to enlarge graph at right):
    • Month of March  = 3,000 acre-feet
    • 2014 Total = 9,700 acre-feet, or 104% 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 be 204,000 acre-feet, which falls 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 will be within the range of Stage 2 (Alert) and near Stage 1 (Normal)


Santa Clara Plain

Coyote Valley

Llagas Subbasin

Santa Clara Plain
- The March managed recharge estimate is 750 acre-feet. The year-to-date managed recharge estimate is 6,500 acre-feet or 55% of the five-year average

- The March groundwater pumping estimate is 10,900 acre-feet. The year-to-date groundwater pumping estimate is 26,200 or 191% of the five-year average

- The groundwater level in Santa Clara Plain (San Jose) is significantly lower than last year and 21 feet lower than the five-year average

Coyote Valley
- The March managed recharge estimate is 550 acre-feet. The year-to-date managed recharge estimate is 2,200 acre-feet, or 82% of the five-year average

- The March groundwater pumping estimate is 900 acre-feet. The year-to-date groundwater pumping estimate is 2,400 acre-feet, or 100% of the five-year average 

- The groundwater level in Coyote Valley is about four feet lower than last year and six feet lower than the five-year average
Llagas Subbasin
- The March managed recharge estimate is 650 acre-feet. The year-to-date managed recharge estimate is 2,650 acre-feet, or 49% of the five-year average 

- The March groundwater pumping estimate is 3,000 acre-feet. The year-to-date groundwater pumping estimate is 10,100 acre-feet, or 170% of the five-year average 

- The groundwater level in Llagas Subbasin (San Martin) is about 23 feet lower than last year and 25 feet lower than the five-year average

       
 

Treated water 

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  •   Treated Water Delivered  Below average demands of 5,800 acre-feet delivered in March
  • This total is 82% of the five-year average for March
  • Estimated year-to-date = 13,400 acre-feet
       
 

 
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
  • District will be reporting on progress towards meeting the call for 20% starting in April
       
 


Recycled
water

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  •   Recycled WaterEstimated March 2014 production  =  1,412 acre-feet (billed semi-annually)
  • Estimated year-to-date = 3,957 acre-feet or 170% of the five-year average
  • Silicon Valley Advanced Water Purification Center was completed and began delivery of high quality Reverse Osmosis treated recycled water for blending with existing tertiary recycled water on March 25, 2014