California groundwater authority promotes water conservation

The Glenn Groundwater Authority (GGA) is encouraging residents to conserve water to help the local groundwater basin.

In a press release, the authority noted, “Eight of the last 10 years have been classified as below normal, dry, or critical based on the Sacramento Valley Water Year Hydrologic Classification. The Northern Sierra Precipitation 8-Station Index states our region is only at 79% of average precipitation this year. The U.S. Drought Monitor shows over 97% of Glenn County is in Extreme Drought.”

The GGA is the official groundwater sustainability agency (GSA) managing the Glenn County portion of the Colusa Subbasin, which covers the area generally south of Stony Creek, east of the coast ranges, west of the Sacramento River, and north of the Glenn-Colusa County line.

In coordination with the neighboring GSA, the Colusa Groundwater Authority, the GGA submitted the Colusa Subbasin Groundwater Sustainability Plan (GSP) as required by the Sustainability Groundwater Management Act (SGMA) in January, 2022. The long-term, comprehensive, dynamic plan will guide transboundary water resources.

“Goals of the GSP are to maintain locally-managed sustainable groundwater resources to preserve and enhance the economic viability, social well-being, and culture of all who use groundwater, while avoiding undesirable results,” such as land subsidence.

During the development of the required annual report, basin conditions are evaluated at least annually. However, groundwater levels have generally dropped since 2020 according to a report submitted in April, 2022.

“Since 2015, land subsidence has occurred in various areas, but most prominent(ly) between Orland and Artois with up to -1.5 feet (-45.7 cm) of vertical displacement. It is unclear how much of this subsidence is permanent,” according to Glenn Groundwater Authority officials.

While GGA is evaluating projects and longer-term options to enhance drought resiliency, the release specified that “immediate term solutions are being sought by Glenn County, cities, and local water providers.” The agency is planning for groundwater recharge and additional monitoring for land subsidence.

In addition to curtailing garden & lawn watering, local agricultural producers have also experienced significant cuts or cancellations of water allocations. “In many cases, annual crops have been fallowed or fewer acres planted while trees and other permanent crops are being irrigated sparingly,” read the GGA release.

“Agricultural water users are similarly encouraged to utilize best management practices, conserve water as much as possible, and minimize groundwater pumping. Coordinate with neighbors, when possible, to minimize possible well interference.”