
Groundwater
Holistic, Sustainable Solutions for the Future
West Yost’s Groundwater Team is unmatched in its ability to design and implement holistic, sustainable solutions that fuse the needs of clients, the environment, and surrounding communities. Our forward-thinking scientists and environmental engineers identify problems precisely and solve them through a methodical process that weighs political, legal, and technical considerations while building consensus for ideas and solutions.
Our groundwater resources team offers a full-service approach, including:
- General consulting in the areas of water resources, hydrology, and hydrogeology
- Studies and planning
- Modeling
- Regulatory and permitting assistance
- Designs for well rehabilitation, new municipal wells, and ASR wells
- Watermaster services
- Funding assistance
- Construction phase services
- Operations and maintenance (O&M)
- Optimization of existing systems
- Groundwater management plans
- Development and application of numerical models to evaluate the hydrologic and water quality response of ground and surface waters
- Recharge master plans and managed aquifer recharge projects
- Salt and nutrient management plans
- Development and implementation of monitoring plans for surface water, groundwater, and land subsidence
- Development and implementation of data‐management systems
West Yost brings the value of understanding and knowledge gained from groundwater regulatory compliance with the Sustainable Groundwater Management Act (SGMA) and Groundwater Sustainability Agency (GSA) formation; groundwater modeling and aquifer evaluations; and planning and design of facilities that best meet your long-term goals of quantity, quality, and conjunctive use supply strategies. In addition, West Yost staff apply construction and O&M knowledge to the design process to improve construction document quality and reduce construction risks, costs, and delays.
Project Highlights

Development and Application of High-Resolution Models to Recalculate the Chino Basin Safe Yield and Follow-on Model Applications
Chino Basin Watermaster
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.
Colusa Subbasin Groundwater Sustainability Plan and SGMA Technical Support Services
Colusa Groundwater Sustainability Agency and Glenn Groundwater Sustainability Agency
At nearly three-quarters of a million acres, the Colusa Subbasin is the largest groundwater basin in the Sacramento Valley and the eighth largest in California. Building on our years of experience with groundwater in the Sacramento Valley, West Yost has become a valued member of a multi-consultant team responsible for development of the Groundwater Sustainability Plan (GSP) for the Colusa Subbasin. We are involved in all aspects of GSP development, including engaging with stakeholders and the public, and have the primary responsibility for producing the GSP for the Colusa Groundwater Sustainability Agency (GSA) and Glenn GSA.


Development and Implementation of a Salt and Nutrient Management Plan for the San Juan Creek Watershed
South Orange County Wastewater Authority
In May 2009, the State Board adopted a Recycled Water Policy to move aggressively towards a sustainable water future by encouraging local and regional water agencies to move toward clean, abundant, local water for California, emphasizing the need to increase the reuse of recycled water in addition to water conservation, the maintenance of infrastructure, and the capture of stormwater, including dry-weather urban runoff.

Watermaster Services for Water Rights Compliance and Groundwater Management
Six Basins Watermaster
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..

A Place-to-Play Test Well Conversion
City of Santa Rosa
As part of the City of Santa Rosa’s Emergency Groundwater Supply Program, West Yost worked with a well redevelopment contractor to rehabilitate the City’s 10-year old test well at the A Place to Play Park. Rehabilitation included: video inspection and initial pump test; swabbing and brushing; chlorination; airlift redevelopment; and pumping redevelopment; followed by a final pump test and video inspection.
Monitoring for Impact of Groundwater Management Plans on Critical Riparian Habitat
Chino Basin Watermaster and Inland Empire Utilities Agency
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).

Team Spotlight
Our groundwater experts include specialists in geology, hydrogeology, engineering geology, civil engineering and water treatment plant operators. We provide over 150 years of combined experience. Meet some of our team below and on our project pages.

Samantha Adams
Groundwater Business Sector Leader

Samantha Adams
Groundwater Business Sector Leader
“I’m passionate about the environment and water. My work is a meaningful contribution to environmental stewardship with particularly challenging issues to solve in California. I have grown to love consulting work because of the diversity of clients I succeed in helping. While the challenges are similar, they all have unique and interesting problems. That makes every day unique and exciting.
The Upper Temescal Valley Salt and Nutrient management Plan (SNMP) for both Elsinore Valley Municipal Water District and Eastern Municipal Water District, is a project I began in 2013 and it has finally completed. The Regional Board approved a basin plan amendment to incorporate into the new management plan. I am really proud that I could lead a team that provided a very creative regulatory solution and saved our clients a lot of money. I enjoyed being part of the team that negotiated the solution with regulators and led the technical work, which contributed to the evolution of the methods over time. I also led the successful stakeholder process.

Mark Wildermuth, PE
Principal III

Mark Wildermuth, PE
Principal III
“At this point in my career, what excites me the most, what revs me up in the morning, is working with younger talented staff on really important groundwater management problems. While my grey hair often puts me in a teaching mode, their youth and enthusiasm really elevate my spirit.
My greatest accomplishment was being able to lead the development and implementation of the 2000 Chino Basin Optimum Basin Management Program. This program is responsible for: the sustainable management of one of the largest groundwater basins in southern California serving agricultural and municipal water users and about a million people; development of innovative management strategies; providing over $1 billion in benefits; and attracting $100s of million in grant funding.

Ken Loy, PG, CEG, CHG
Hydrogeologist

Ken Loy, PG, CEG, CHG
Hydrogeologist
“I enjoy working with our clients and developing an internal West Yost team that can provide the solutions each client needs. We have the right resources on the Groundwater team. Our strength is that in addition to hydrogeology we have the ability to draw upon many internal resources for civil and mechanical engineering. We also have a pool of experts with whom we have built long, trusted relationships for whatever water needs arise. I find it rewarding to work with our clients to develop the best, customized team for each project.
I am proud of working on multidisciplinary teams to meet the variety of project needs for our longstanding clients, such as the City of Modesto. We are able to meet their needs at any moment. We have provided a variety of planning, modeling, design, and construction management services for several departments, including water and wastewater services, over a long period of time. I enjoy the fact that what I do related to groundwater is part of a bigger picture for their water and wastewater services. They have provided us with excellent feedback and appreciated our performance. I have also conducted three different well trainings for City of Modesto, in addition to AWWA and City of Redding.”
Available Positions
Multiple Senior-Level Positions Available
Posted
This senior level contributor will oversee and manage construction management projects…
Senior Designer/CAD Operator
Posted
The CAD Designer/Operator is a key member of the engineering team, with responsibility for product designs and various projects in the public and private sectors. They will collaborate with a team of civil engineers and project managers to provide outstanding engineering designs and construction documents.