Page 100 - Yucaipa Sustainable Groundwater Management Agency - Yucaipa SGMA

• Initiated a shallow groundwater investigation of an upland wetland habitat area previously
devastated by fire near the Sweetwater Reservoir in San Diego, California. Changes in
groundwater elevations in response to precipitation and surface water flows, coupled with
soil characteristics, were used to create a numerical model to simulate the height of the
capillary fringe above the water table. The findings from the investigation were used to help
design a habitat restoration program for the area.
• Project manager for investigating the performance and water quality of two municipal water
supply wells for the City of San Clemente, one of which experienced increasing chloride and
TDS concentrations. The investigation led to recommendations to modify the well to improve
water quality and production.
• Project manager for evaluating previous hydrogeological investigations conducted by others
that studied the potential impacts of groundwater production from fractured rock on the
water levels at adjacent private wells and riparian habitat for the City of Poway.

Numerical Modeling Experience
• Modified an existing 3-D MODFLOW-OWHM numerical model to incorporate recent
groundwater level and pumping data for the Borrego Groundwater Basin. The updated model
was used to validate calibration of the numerical model and define uncertainty in estimates
of aquifer storage.
• Modified an existing 2-D MODLFOW numerical model by expanding the model domain with
additional layers to better represent the geology of the groundwater basin and incorporating
site-specific aquifer characteristics derived from local aquifer testing. The numerical model
was used to simulate the potential change in water table elevation resulting from additional
recharge from the discharge of imported water to recharge spreading basins.
• Modified an existing 3-D finite-difference numerical model to evaluate the potential impacts
to groundwater levels at a downstream ecological reserve when diverting stream flow and
pumping groundwater at a multipurpose basin upstream of the reserve. The modified
numerical incorporated monthly stress periods to simulate monthly variations in rainfall,
stream flow and evapotranspiration, which was defined using transpiration rates for riparian
vegetation mapped in the reserve. The numerical model results were used to develop an
operational plan for the basin to minimize the impacts to downstream habitat.
• Developed a variably saturated flow model to simulate the potential effects to shallow
groundwater levels and soil moisture when modifying a floodplain for a riparian habitat
restoration project. The numerical model was used to estimate the depth to the water table
and the height of the capillary fringe above the water table. Results from the numerical
model were used to design a habitat mitigation plan to sustain new riparian habitat.
• Manipulated the existing USGS MODFLOW groundwater numerical model of the Joshua Basin
using Groundwater Vistas to predict changes in aquifer storage as a result of projected
growth in the basin.
• Prepared a 3-D MODFLOW groundwater numerical model to simulate the transport of
dissolved chromium in an aquifer beneath the former Marley Cooling Tower Company facility
in Stockton, California. The numerical model is used to evaluate the hydraulic capture and
plume containment by the remedial well field. Proposed modifications in the pumping
scheme of the remedial well field are evaluated by using the numerical model to predict the
effect of such changes.

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