Page 186 - Yucaipa Sustainable Groundwater Management Agency - Yucaipa SGMA

Edwin H. Lin, PG, CHG

that planned recycled water projects would not exceed the available assimilative capacity in
any local subregions.
San Bernardino Valley Municipal Water District (Valley District) Yucaipa Infiltration Testing
Valley District and its partner agencies and water retailers are preparing to manage its
groundwater resources conjunctively with SWP water, and increase basin recharge with
enhanced natural storm runoff and recycled water to meet future demands while maintaining
independence during periods of water shortages. Todd Groundwater developed a Work Plan
to determine the infiltration capacity of vadose zone sediments underlying the proposed
recharge areas. The infiltration testing is currently being planned and conducted by Todd
Groundwater. Estimated infiltration rates will be combined with other hydrogeologic
information (e.g., subsurface stratigraphy, fault mapping, groundwater levels, and water
quality data) to prioritize potential sites, estimate long‐term groundwater banking potential,
and support preliminary design of recharge facilities. Additionally, infiltration rates will be
used to evaluate the impacts (benefits) of various MAR projects scenarios on groundwater
storage and basin perennial yield (using the basin‐wide USGS MODFLOW model) and estimate
subsurface recharge flowpaths to assess groundwater quality changes and recovery
efficiency.
Groundwater Basin Conceptual Models for Baja and Centro Subareas of Mojave River Basin,
Mojave Water Agency
As project hydrogeologist, Mr. Lin developed basin conceptual models and evaluated water
supply and demand conditions for Mojave Water Agency of the Centro and Baja subareas,
two subareas comprising over 2,000 acres in the lower portion of the adjudicated Mojave
River Groundwater Basin. He synthesized findings from historical studies dating back to the
early 1900s with analyses of new geologic, groundwater level and water quality data into one
comprehensive document, which will be used to support future groundwater management
planning, including MAR of imported SWP water. Project responsibilities included
characterization of basin geometry, aquifer properties, impacts of hydraulic (fault) barriers on
groundwater flow; groundwater water level trend analysis; evaluation of impacts of local and
regional pumping and dam construction on surface water flows and downstream recharge
along the Mojave River; development of independent basin subarea water balances;
MODFLOW model water budget extraction and review; groundwater quality characterization;
and water demand forecasting.
Managed Aquifer Recharge Feasibility Studies for Mid‐Valley and CVWD Palm Desert Areas,
and Groundwater Replenishment Expansion Evaluation of the Thomas E. Levy (TEL) Facility,
Coachella Valley Water District (CVWD)
As project manager/lead hydrogeologist for three independent CVWD managed aquifer
recharge feasibility studies, Mr. Lin reviewed CVWD’s domestic pumping and recharge
operations to assess the feasibility of expanding groundwater replenishment through surface
spreading of Colorado River water in the West and East Whitewater River Subbasin Areas of
Benefit. He obtained pertinent data to characterize lithologic, groundwater production,
groundwater level, and water quality conditions across 60 square miles of CVWD’s service
area. Mr. Lin oversaw the construction of three local‐scale MODFLOW/MT3D groundwater
flow and solute transport models used to simulate future groundwater level and water quality
impacts from proposed recharge. Results indicated that desired recharge amounts could be

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Yucaipa Sustainable Groundwater Management Agency - August 9, 2018 - Page 183 of 208