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August 2016
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City of Morgan Hill
2015 Urban Water Management Plan
manage, which includes the Llagas subbasin and the Coyote Valley subarea of the Santa Clara
Valley subbasin. During periods of drought, the imported water supplies available to SCVWD can
be reduced or not provided at all, which would reduce the amount of recharge available to the
groundwater basins. In periods of water shortage, SCVWD works closely with the water suppliers
extracting water from groundwater subbasins they manage in order to minimize overdraft and
subsidence. Typically, when SCVWD identifies a risk to regional supply reliability, they call for
urban water suppliers to reduce their water use through voluntary and mandatory water
conservation ordinance.
Additionally, during a drought, SCVWD anticipates the City to use groundwater reserves.
Historical groundwater monitoring by SCVWD in the Llagas subbasin also indicates stable
groundwater conditions during multiple-year droughts. Through SCVWD’s implementation of
conjunctive use programs, the Llagas groundwater subbasin has historically experienced well
managed levels. As a result of this management, the Llagas subbasin is considered a reliable
source of supply during water shortages. While pumping may exceed recharge during a drought,
basin management practices have prevented long-term adverse conditions.