
The Chino Basin is a large alluvial groundwater basin in Southern California with storage exceeding five million acre-feet. Groundwater in the Chino Basin generally flows from the forebay regions in the north towards the Prado Flood-Control Basin in the south (“Prado Basin”). Depth to groundwater is relatively shallow in the Prado Basin area, which allows for groundwater/surface-water interaction.
The Chino Basin Watermaster, the agency responsible for groundwater basin management, implements aggressive groundwater-supply programs that include controlled overdraft and the possibility of causing groundwater-level declines in the basin. The EIR for the groundwater-supply program identified the lowering of groundwater levels as a potentially adverse impact on the Prado Basin’s riparian vegetation that consumptively uses shallow groundwater.
Our team developed the monitoring and reporting program and has recently begun its implementation. The first step was to design, drill, construct, and develop 16 monitoring wells located near the riparian habitat to track changes in groundwater levels within the shallow or perched aquifer systems. The monitoring program also includes characterization of the extent and quality of the riparian habitat over time, which required the acquisition and analysis of remote-sensing data from the Landsat program, high-resolution aerial photography, and field vegetation surveys. The program also involves monitoring all factors that could potentially impact the habitat (not only changes in groundwater levels), including surface-water discharge, precipitation, temperature, wildfire, and pests, among others. Lastly, the program includes groundwater-flow model projections of future drawdown to identify areas of prospective impacts on riparian habitat. In 2017, the Watermaster published the first annual report, which identified no current or future adverse effects on the riparian habitat and recommended certain refinements to the monitoring program.
Team Spotlight

Andy Malone, PG
Principal Geologist II

Andy Malone, PG
Principal Geologist II
“Groundwater interests me because it’s a renewable resource. I try to live my life, personally and professionally, with a consideration for long-term sustainability. My job at West Yost, and the fantastic people that I get to work with and work for, have given meaningfulness and energy to my life.
The most rewarding project I have worked on has been a long-term project to manage land subsidence in the Chino Basin. The technical focus of the project has been on understanding the relationship between aquifer-system hydraulics and aquifer-system mechanics (i.e. deformation of the aquifer-system sediments that can result in land subsidence). The project has been instrumental in my professional development. Along the way, I have been fortunate to work with, and learn from, eminent professionals in this field of study. Over the last two decades the project has involved: installing monitoring facilities; performing aquifer-system stress tests; conducting monitoring programs; computer-simulation modeling of groundwater flow and aquifer-system deformation; and using this information to develop practical, adaptive solutions to minimize the future occurrence of land subsidence in a heavily urbanized groundwater basin.”

Veva Weamer
Supervising Scientist

Veva Weamer
Supervising Scientist
“I get to work on a variety of projects and each one is unique, different, and interesting, which I find exciting! I work in different regions and each has unique circumstances, challenges, and solutions to supply water to their communities. It is work that most people don’t know about or think about, but is very important because everyone uses water. My work is in the background helping agencies supply water their communities. It is very interesting to me!
I am proud of a project I am working on now to develop a Groundwater Sustainability Plan for the Spadra Basin. It will allow these agencies to continue to use a local source of water for the long-term future. Our plan will ensure that the Spadra Basin is a sustainable source of water supply and optimize the use of the basin.”

Emily McCord
Scientist II

Emily McCord
Scientist II
“The thing that most excites me about my work is the problem solving and analysis! I love diving into the data to see what we can learn from a massive amount of information. I feel like Sherlock Holmes! Water is my favorite substance, I love to surf, I love swimming, and I love rivers–so I majored in hydrology.
I am in charge of all of the field work we do in Southern California. At the start of a new field program, I do preliminary investigation on site to arrange what we need. I recently went to Borrego Springs for the Semi-Annual Groundwater Monitoring project to explore the site. I started from a list and figured out where all of the wells were. Then we completed the sampling for many of them for the Watermaster Services that we provide. I was also really pleased to recently design and installed a gauge from the ground up at Oxbow Lake in Prado Basin. I had to brainstorm with others to figure out how to build so it would not wash away in the stream. I had fun using a drill and mixing cement. It went well and looks very nice to the public eye.”