
The Six Basins are a group of adjacent groundwater sub-basins located in Eastern Los Angeles and Western San Bernardino Counties. The pumping rights from the Six Basins were adjudicated in 1998 through a stipulated judgment, which established the Six Basins Watermaster (“Watermaster”) to implement the Judgment. The Judgment prescribes a physical solution for the coordinated management of the Six Basins with the objective that the parties to the Judgment can reliably pump their respective rights and maximize the beneficial use of groundwater. Our team was retained in 2011 to perform technical and administrative services for the Watermaster, including:
- Preparing for and conducting monthly Board meetings
- Implementing field groundwater monitoring programs
- Implementing and maintaining a data management system
- Setting the annual operating yield and pumping rights
- Coordinating recharge activities
- Preparing the annual budget
- Performing financial management
- Calculating the annual change in storage
- Complying with CASGEM and the SGMA
- Preparing an annual report to the Court
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.”

Terrinda Alonzo
Geologist II

Terrinda Alonzo
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.

Carolina Sanchez
Senior Engineer I

Carolina Sanchez
Senior Engineer I
“Water is such an important aspect of our lives and most people where we live are fortunate to not have to think about where their water comes from and where it is going. Most people don’t consider how many opportunities there are to improve our reliability to secure that the resources are here forever for us all. My work days are spent making it more reliable, which is very exciting. There is a real live application and direct impact results from what I am doing.
Last year we facilitated a stakeholder-led collaborative process to review all of the challenges coming up for a specific groundwater basin in the next 20 years. Our task was to obtain information, ideas and feedback from the stakeholders on how to address each of the challenges facing the region to stay one step ahead in their water management. Many specific interests were represented and each had to take a more regional view to see the benefits for everyone and how they relate to one another. Together we developed the Optimum Basin Management Plan Update which will guide the region for the next 20 years!”