BOARD AGENDA MEMORANDUM
SUBJECT:
Title
Groundwater Conditions and Recharge Operations (Responding to Board Member Request R-19-0005).
End
RECOMMENDATION:
Recommendation
Receive an update on groundwater conditions and planned recharge pond operations including the Dr. Robert Gross recharge ponds on Upper Penitencia Creek.
Body
SUMMARY:
Water supply conditions in Santa Clara County have been favorable since the wet winter of 2016-2017 that marked the end of the recent drought. Storage in Santa Clara Valley Water District (Valley Water) and state reservoirs is at nearly 100% of the 20-year average for April. The increased snowpack in the Sierra and improved conditions in the Delta have allowed for higher allocations of imported water from the Central Valley Project and State Water Project, resulting in ample supply available for water treatment plants and the Valley Water managed recharge program. Groundwater storage has fully recovered to pre-drought conditions, with new historic high groundwater levels in many North County wells.
Since 2018, Valley Water has reduced managed recharge operations in the North County since the Santa Clara Subbasin is essentially full and groundwater pumping continues to be low. Full basin conditions are contributing to high artesian pressures in many areas, which has resulted in reports of flowing artesian wells and operational concerns for some retailers. Valley Water staff is planning to maintain a reduced managed recharge program in the North County for 2019 based on extraordinary groundwater conditions, and would like to provide an update to the Board.
Groundwater Conditions
Increased reliance on groundwater and reduced recharge during the 2012-2016 drought lowered groundwater levels and storage. Estimated groundwater storage was about 232,000 acre-feet (AF) at the end of 2015, in the severe stage (Stage 3) of the Water Shortage Contingency Plan (WSCP). With little water for recharge, Valley Water took the opportun...
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