The Chino Basin adjudication was settled in 1978 through a stipulated agreement. Through other agreements, the Chino Basin Watermaster was required to recalculate the safe yield and other hydrologic items in 2011. Our groundwater team developed and implemented a methodology based on scientific principles and detailed numerical models to develop a complete hydrologic description of the Chino Basin over the 1960-2011 calibration period and the 2012-2071 planning period.
Watermaster was also required to calculate net Santa Ana River recharge and how the net Santa Ana River recharge changes with groundwater pumping and storage management. Working with Watermaster staff and legal counsel, our team participated in a series of workshops and two-day peer review sessions to thoroughly review the methodology, assumptions, data, and computational results. The resulting model was praised during the peer review process as one of the most comprehensive and thoughtfully developed groundwater models ever built to manage a groundwater basin. Watermaster and the Court accepted the technical work and the recalculated safe yield.
The model was updated and used to develop a storage framework (management) plan for up to 1,000,000 acre-feet of water banking activities, to develop an updated Salt and Nutrient Management Plan for the basin, and to estimate the impacts of groundwater management activities on surface water discharge and riparian habitat in the Prado Reservoir area and upstream habitat areas along the Santa Ana River. The model is currently being updated to include a subsidence module and is being recalibrated to estimate the safe yield for 2021 through 2030.
Team Spotlight
Garrett Rapp, PE
Associate Engineer II
Garrett Rapp, PE
Associate Engineer II
“The collective drive by our team and clients to tackle challenging water management problems is inspiring. I enjoy being able to work with a diverse team to develop creative solutions to navigate the many challenges of cost, regulations, and a changing environment that affect each of our clients in a unique way.
Our groundwater modeling support as the engineer for the Chino Basin Watermaster is immensely gratifying. We have an exciting opportunity to perform creative projects to support environmental review, management decisions, and regulatory compliance in a basin serving 1.2 million people. The diversity of the client and stakeholders provides a welcome opportunity to communicate our work and build trusting relationships.”
Eric Chiang
Principal Scientist II
Eric Chiang
Principal Scientist II
“It is exciting to overcome new challenges in modeling works by finding innovating solutions.
I am proud to accomplish the modeling works of the San Juan Creek Watershed and San Juan Valley Groundwater Basins with GSFLOW by creating a graphical user interface for the Processing Modflow application and putting all required data together.”