TRUCKEE, Calif. — At its August 7 meeting, the Placer County Water Agency (PCWA) Board of Directors adopted the updated Martis Valley Groundwater Management Plan (GMP) to continue the sustainable, long-term stewardship of this vital resource.

“The Martis Valley Groundwater Management Plan is another example of how PCWA works collaboratively with its partners to assure quality and sustainability while managing our crucial water resources for Placer County,” said PCWA Director Josh Alpine, whose district includes Martis Valley.

The Board’s approval followed a public hearing and an overview of the 80-page technical update to the 2019 Martis Valley Groundwater Management Plan prepared by GEI Consultants and Balanced Hydrologics, Inc. for the Truckee Donner Public Utility District (TDPUD), Northstar Community Services District (NCSD), and PCWA. These three agencies work together to manage groundwater in Martis Valley, which straddles Placer and Nevada counties.

According to Darin Reintjes, Director of Resource Management, the plan’s purpose is to improve the understanding and management of the groundwater resource in Martis Valley while providing a framework for partner agencies to align policy and implement effective programs. The Martis Valley Groundwater Basin is currently classified by the California Department of Water Resources as a “Very Low Priority” basin, meaning it is not subject to the Sustainable Groundwater Management Act’s regulatory requirements.

“This plan is not mandatory, regulatory, or an enforcement effort,” Reintjes said. “Rather, it’s a model for collaboration and cooperation between agencies and stakeholders with common goals.”

PCWA adopted its first groundwater management plan for portions of Martis Valley in 1998 and has worked in partnership with TDPUD and NCSD since the development of the 2013 Groundwater Management Plan.

The updated plan retains the Best Management Objectives from earlier versions. These focus on protecting groundwater resources and the environment, managing resources under the Truckee River Operating Agreement, collaborating with groundwater users and stakeholders, and using the best available science and technology to guide decisions.

That model has worked well, staff noted. Monthly monitoring of the groundwater levels allows the agencies to keep a close eye on the basin. Following stakeholder review, only minor updates to the 2019 plan were recommended, Reintjes explained. Those included updated maps and data, and a change in the requirement to update the plan from every 5-years to 10-years, unless annual monitoring indicates the need for earlier revisions.

“Overall, the Martis Valley Groundwater Basin is being operated well within the sustainable yield of the basin and consistently recharges from precipitation and snowmelt,” Reintjes said.

Through wet and dry years since 2016, the basin’s estimated groundwater storage has remained between 350,000 and 400,000 acre-feet, according to the report presented to the Board. As part of ongoing implementation, a licensed California hydrogeologist will continue to review monitored data annually and report on the basin’s condition.

Located at more than 5,700 feet in the eastern Sierra, the Martis Valley Groundwater Basin covers about 57 square miles north of Lake Tahoe. Mountains along the valley’s southern edge rise above 8,000 feet, and the valley is bisected by Martis Creek, which flows north into the Truckee River.