Page 49 - Yucaipa Sustainable Groundwater Management Agency - Yucaipa SGMA

Johnson Yeh, PhD, PG, CHG

Years of Experience: 28
Years with GEOSCIENCE: 28
Education:
BS, Geology, National Taiwan University
MS, Geology, National Taiwan University
PhD, Sedimentology, University of Southern California
Professional Registrations:
California Professional Geologist (No. 6371)
Certified California Hydrogeologist (No. 422)

What Johnson Brings to the Project:
• Extensive water modeling experience—can work with GSA member staff to develop accurate
models with sufficient detail to inform future groundwater sustainability strategies
• Understands how to combine multiple models and data sources—provide a clear picture of the
current groundwater conditions and allow for accurate predictions and estimates
• Collaborates with the USGS to develop and update groundwater models using MODFLOW and
helped USGS develop GSFLOW
For more than 28 years, Johnson has managed ground water modeling efforts, hydrogeologic
investigations, ground water basin and water quality studies, and artificial recharge projects. He
provides project management and technical direction for hydrogeologic investigations, groundwater
models, and artificial recharge projects. Johnson performs detailed statistical analysis of various types of
data and has been the lead modeler on many high profile projects—in fact, he was instrumental in
helping to resolve one of the larges groundwater rights cases in California, and developed models that
helped a water district client to successfully avoid costly litigation. Johnson has taught graduate level
ground water modeling courses at the University of Southern California and routinely collaborates with
the USGS to develop models in the Yucaipa and San Bernardino areas. His experience and knowledge
will enable him to run scenarios and develop an accurate sustainable yield calculation.
Selected Project Experience
San Bernardino Valley Municipal Water District: Santa Ana River Integrated Model - Johnson is leading
our team in an effort to use existing groundwater and surface water models to develop an integrated
groundwater model for the upper Santa Ana River. The resulting Upper SAR Integrated Model (or
Integrated SAR Model), will be used to determine what factors may contribute to declines SAR flows,
and assess cumulative effects on SAR surface flows and groundwater levels.
Yucaipa Valley Water District: Recycled Water Use Evaluation using the Gateway Sub-basin Focused
Groundwater Model - Johnson was the senior modeler overseeing the construction of a groundwater
model used to predict the impacts of recycled water spreading on groundwater quality and to
downstream municipal wells.

Yucaipa Sustainable Groundwater Management Agency - August 9, 2018 - Page 48 of 208