The Inyo County Water Department and Board of Supervisors expressed concern last week about a Los Angeles Department of Water and Power (LADWP) proposal to reactivate Well V817 in Rose Valley and install an 8-inch diameter water pipeline of approximately 1,540 feet to connect the well to the Los Angeles Aqueduct.
The LADWP plans to pump around 1,100 acre-feet per year from the project area, which is about 10 miles north of Little Lake in northern Rose Valley between South Haiwee Reservoir and Coso Junction. The comment period for the proposed project closed this week on Sept. 4.
The Inyo County Water Department believes the proposal, outlined in the DWP’s Notice of Intent to Adopt an Initial Study/Mitigated Negative Declaration (IS/MND), lacks two key considerations. The first is that under the Owens Valley-Los Angeles Long Term Water Agreement, any new well installed in the Owens Valley must have oversight from the Water Agreement’s Inyo/LA Technical Group. Water Department Director Bob Harrington explained that the DWP has the right to put in new wells, “But the Technical Group looks at the well site, does some testing, and develops an operational plan for it,” he said.
Although Well V817 is technically a pre-existing irrigation well that the DWP acquired when it bought the property for the proposed pipeline project, and although the Water Agreement contains no provision for reactivating a previously existing irrigation well, “My view is that the Technical Group would treat [this well] as a new well,” Harrington said. “The difference between that well and a new well is really just semantic.” He added that the Water Department has yet to discuss this particular issue with the DWP.
The Water Department’s second concern is with the amount of water the DWP proposes pumping from an area so close to Little Lake. Currently, Coso Operating Company pumps groundwater from their property immediately south of the DWP’s project site, transferring that water to their geothermal plant east of Rose Valley. The Water Department recently reduced the Coso Operating Company allotment of water from about 4,800 acre-feet per year, although they typically pump less than that, to about 3,000 acre-feet per year. This reduction was the result of an observed negative impact to the groundwater discharge at Little Lake.
In fact, the Water Department initially recommended that Coso Operating Company pump only 790 acre-feet per year, to keep the reduction in discharge to Little Lake at a maximum of 10%. Because the company chose to pump more, Harrington said, “They’ll probably have to reduce to zero next year.”
The DWP’s proposed 1,100 additional acre-feet per year from the already depleted area could therefore have a significant impact on groundwater levels, discharge to Little Lake, and the Little Lake habitat.
Yet the DWP IS/MND argues that the additional pumping will have no significant impact on groundwater discharge. The IS/MND adds that should a significant impact be observed at monitoring wells, and should trigger levels be reached according to a previous Memorandum of Understanding (MOU) between Coso Operating Company and the DWP, “The Coso Operating Company must subordinate to LADWP and reduce its pumping levels, thereby ensuring that groundwater supplies are protected.”
However, the County’s comment letter to the DWP expressed concern that the IS/MND does not identify the MOU as a mitigation measure; therefore the Water Department and Board cannot know whether this purported mitigation measure would be enforceable. The IS/MND also does not specify what level of groundwater pumping might continue to occur if Coso Operating Company’s pumping is reduced to less than the DWP’s.
With these uncertainties, the Water Department and Board argued that the DWP should conduct a more rigorous Environmental Impact Report under CEQA (California Environmental Quality Act) for the Rose Valley Pipeline project, rather than the lower-level IS/MND. The Board directed Harrington to sign and send the letter, but the Water Department and Board may have to wait a few months for a response from the DWP, Harrington said. He added that the Water Department will continue to discuss its concerns with the project at the next Inyo/LA Technical Group meeting within a month or two.