Update on Tri-Valley water basin

(The following is a corrected version of an earlier story)

By Deb Murphy

All the parties involved in the Tri Valley water basin will be waiting two months to see if the California Water Commission accepts the recommendation to consider the groundwater from Chalfant to Benton valleys a sub-basin of the Owens Valley basin.

The Department of Water Resources rejected a request from Inyo County to adjust boundaries between the Owens River and Tri Valley groundwater basins.  The County appealed the DWR’s decision last week.

All this is part of the Sustainable Groundwater Management Act, a bill requiring Groundwater Sustainability Agencies to develop plans to protect aquifers from over-draft.

As an adjudicated basin, that part of the Owens Valley Basin under land owned by Los Angeles Department of Water and Power is exempt. There had been the hope that the Tri Valley aquifer could be separated and identified as a low priority basin and not have to develop an agency or a plan. But, according to Inyo County Water Director Bob Harrington, Tri Valley would probably be classified as medium priority even as a sub-basin to Owens.

All this sounds like policy wonkism, unless you’re a member of the Tri-Valley Groundwater Management District with neither budget nor staff to form an agency; or unless you’re intent on protecting Fish Slough and not convinced potential over-draft from Tri Valley won’t deplete the Slough’s water sources.

The appeal, approved by the Inyo Board of Supervisors July 19, reiterates information from studies by the US Geological Survey and California Department of Fish and Wildlife, citing “the presence of a bedrock barrier between Tri Valley and Owens Valley that impedes groundwater and deflects most groundwater flow west along faults where it discharges at Fish Slough.”

The letter goes on to note the USGS flow model indicating less than 2 percent of the regional basin originates in the Tri Valley basin. In addition, hydrographs of the basins indicate a “contrast between groundwater level patterns over time:” between the two.

While Inyo had no issues with the DWR’s recommendation that Fish Slough be identified as a sub-basin of the Owens Valley, there is a concern the recommendation “will diminish the emphasis that Fish Slough will receive in future groundwater sustainability planning.”

“Fish Slough could be managed either way,” Supervisor Dan Totheroh said at the July 19 meeting, “it just would have been easier” if the Tri Valle and Owens Valley basins were separated.

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One Response to Update on Tri-Valley water basin

  1. Philip Anaya August 4, 2016 at 2:35 pm #

    When the California Department of Water Resources identified the Owens River Basin and classified it as critically endangered ,Tri Valley was included meaning that Tri Valley extractions could effect the Owens Basin water tables and like wise the reverse . The science that the DWR applies to these Basins is as good as the Inyo County Water Departments assessment and Inyo has not been able to satisfy DWR that the two basins are not hydrologicaly separated . The two methods for Boundary Modification are 1. Scientific and 2. Jurisdictional . Based on what was said by DWR staff at the last Calif. Water Commission Meeting some of the rejected “Modification Requests” might have been accepted by DWR Staff for their recommendation to the State Water Commission Board later this summer if they had used the “Jurisdictional” process.
    With that said Inyo County had a “high bar” to get the science folks at DWR to change their initial finding that included Tri Valley . Currently some folks retired from the BLM who studied the hydrology of Fish Slough and Tri Valley dispute the science provided by Inyo County to the DWR. A jurisdictional process involves a significant amount of work with public and Governmental Entity meetings , a lot more work than presenting the scientific evidence . The real problem is that there are some significant unknowns with Tri Valley.
    The extraction of groundwater in Tri valley is utilized in Agriculture . Except for the effects from LADWP extractions in the Owens Valley, Tri Valley is pretty much sustainable . The soil water levels and water tables are obviously sufficient for agriculture but there has been talk in the past of an owner selling and building a pipe for water into the LA Aqueduct. SGMA will regulate that.
    Also the recent attempted reactivation of 2 LADWP production wells that are currently in permanent off status could lower the water tables there and in Fish Slough something that we need to prevent forever. I hate to disagree with the Inyo County Water Department but Tri Valley needs to be regulated and protected by the SGMA and the precedent set that non-adjudicated portion of a basin will not be effected or drained by the adjudicated portion . This is especially important in the Owens River Basin where the LTWA regulates SGMA in the Valley and it is full of difficulties and a difficult LADWP. Just a note, not to confuse the issue, but the adjudicated Portions of the Owens River Basin do not require the establishment of a GSA, a Groundwater Sustainability Agency or it’s GSP, a Groundwater Sustainability policy. The adjudicated portion of the Owens River Basin is not exempt from SGMA . Annual reports are required as are yard stick progress over the years in raising depleted water tables in the Valley towards sustainability . SGMA is regulation and oversight of the DWP in the Owens River Basin into the future. The Supes should have a SGMA workshop. DWR is paying for facilitators. Everything that we can do to strengthen SGMA in the Eastern Sierra is going to be necessary knowing how DWP can slide around on things historically. The Supes should reconsider the Boundary request, accept the DWR staff report to include Tri Valley and Fish Slough, get the GSA and the GSP rolling and begin to deal with the other non adjudicated areas of the Basin. The SGMA needs a full time Inyo County administrator who is well versed in law and in the current and historic Owens Valley water issues. The County has some folks in vital responsible positions wearing too many hats and SGMA at this point of time needs a mentor in charge in the Owens Valley . We have an a Water Department dedicated to the LTWA. How about one more “dedicated” staff member taking us into the next 100 years with SGMA.


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