By Deb Murphy
The California Department of Water Resources rejected a multi-agency request for a basin boundary modification that would separate the Tri-Valley (Hammil, Chalfant and Benton) water basin from the Owens Valley basin.
In addition, DWR identified Fish Slough as a sub-basin, the majority of which lies in the Tri-Valley area.
Only dedicated water-watchers and a handful of farmers off Hwy. 6 fully understand what that means. Briefly: the Sustainable Groundwater Management Act required all medium and high priority water basins to form Groundwater Sustainability Agencies which would then develop Groundwater Sustainability Plans, in essence to avoid the mess that exists in the Central Valley.
The Owens Valley Basin on land owned by the Los Angeles Department of Water and Power was deemed an “adjudicated basin” courtesy of the Long Term Water Agreement which, hypothetically, safeguards groundwater as well as requiring mitigation for negative impacts on the environment from over-pumping.
The Tri-Valley Groundwater Management District, Inyo and Mono counties supported the boundary re-alignment that coincided with the county line. Inyo was the lead agency on the request.
The hope of Tri-Valley, an all-volunteer agency with no budget, was the separate basin would be identified as low-priority requiring neither a GSA nor a GSP.
As one of the handful of alfalfa growers in the Tri-Valley area, district board member Dave Doonan isn’t too happy with the decision. “You could almost count on two hands the number of (impacted) water users in the district,” he said. “If we can’t afford to do a plan, the state will.”
The issue of declining agriculture is big with Doonan. “Agriculture is elastic,” he said. “If we have a bad water year, we can reduce production.” If ag is replaced with housing tracts and strip malls, the elasticity snaps.
Inyo’s Water Department’s request was based on science, not political boundaries.
The science is explained in the request summary: “The request is based on the presence of a subsurface barrier to groundwater flow between Chalfant Valley and Owens Valley that results in groundwater discharge to springs and wetlands at Fish Slough and relatively little groundwater flow from the Tri Valleys region into Owens Valley. The evidence for the groundwater barrier is geophysical (a gravity anomaly indicative of a bedrock barrier in the alluvial basin fill), geological (a fault that diverts groundwater from the Tri Valley area into springs and wetlands at Fish Slough) and hydrological (groundwater discharge at Fish Slough and modeling suggesting relatively low groundwater flux from the Tri Valley region into Owens Valley.”
According to Water Department Director Bob Harrington, DWR “didn’t think our evidence for a groundwater barrier was sufficient and they had received a lot of opposition to the request from tribes.”
Comments were provided by the Big Pine Paiute Tribe of the Owens Valley, Ceal Klinger and the Owens Valley Committee questioning the science and urging protection of Fish Slough water sources.
According to Harrington, Tri-Valley “would have to include Fish Slough in any plan they develop.” The same is true of the portion of the slough that lies in Inyo, but “the only groundwater pumping in Owens Valley that would be likely to affect Fish Slough would be LADWP’s and that would be regulated under the Long Term Water Agreement, not SGMA.”
So what happens next? According to Doonan, the district is information gathering and talking to state legislators. Harrington outlined the state process: “The DWR presents draft recommendations in a briefing to the California Water Commission on July 21 and then presents final recommendations to the September 21. The Commission adopts recommendations and they’re published in an update to Bulletin 118.”