On March 25, the Inyo County Board of Supervisors upheld the Inyo Planning Commission’s denial of an appeal from Little Lake Ranch, LLC over groundwater pumping by Coso Operating Company in Rose Valley.
Coso Operating Company has been pumping water from two wells on the Hay Ranch in Rose Valley since 2009. The water is used to replenish Coso’s geothermal well fields.
Last August, the Inyo County Water Department approved an extension to the pumping at a rate of 3,040 acre feet/year until June, 2014, down from the original 4,839 acre feet allotment.
Little Lake Ranch, a privately owned duck club that maintains the Lake and nearby areas for waterfowl and game birds, appealed the decision.
The Environmental Impact Review (EIR) for the proposed pumping in 2009 dictated that an independent consultant monitor the groundwater basin to ensure that the Coso project cause no greater than a 10 percent decrease to groundwater inflow to Little Lake. This 10 percent decrease would have a marked effect on the Lake because, explained Inyo County Water Department Director Bob Harrington, “Little Lake is completely supported by groundwater.”
While Harrington said the 10 percent level doesn’t appear to have been reached, “It’s a little hard to measure,” he added. This is because the monitoring wells used to ensure that Coso’s pumping doesn’t draw down groundwater to “trigger” levels are affected not only by groundwater but also by the fluctuating level of Little Lake itself.
One monitoring well that exceeded its trigger levels last summer was affected only after the water level of the Lake dropped. If pumping had triggered the drop, according to the County Planning Department’s agenda packet, the drop in the monitoring well should have preceded the drop in Little Lake’s water level.
At Tuesday’s Board of Supervisors hearing, Harrington suggested that the “triggers” needed to be looked at and modified. Yet he also acknowledged that the effect of Coso’s wells is expanding, which is why the Water Department is requiring Coso to cease pumping as of June this year.
“We will continue to collect data and do some more evaluation as we see the system recover,” Harrington said.
While the June cutoff has offered some reassurance to Little Lake Ranch, representative Gary Arnold expressed the private club’s greater concern about the impact of the proposed Los Angeles Department of Water and Power (LADWP) Rose Valley Pipeline Project.
The DWP project would consist of an eight-inch diameter water pipeline of about 1,540 feet, connecting an existing well in Rose Valley to the Los Angeles Aqueduct to draw water from the deep aquifer.
“The grist of our appeal is not against [monitoring consultant] DBS&A, Coso Geothermal or Dr. Harrington, for whom we have a good deal of respect, said Arnold; “Our main concern is LADWP. They are under no one’s control.”
Arnold noted that the DWP has proposed pumping about 1,000 acre feet per year through the Rose Valley Pipeline. He expressed Little Lake’s concern that allowing Coso to continue pumping without considering that the DWP may soon begin its own pumping “is folly.”
“Looking at the Rose Valley monitoring graphs, there is no question that there is a troubling downward trend with underwater levels falling,” Arnold said at Tuesday’s Board meeting. “It looks like the underground aquifer is lower and being taken out in excess of recharge.”
Thus far, Harrington said, the DWP has only notified the County of an Intent to File a Negative Declaration (an environmental review document) for the project. “They got a lot of comments from the County, Coso, and Little Lake about how the [Negative Declaration] wasn’t accurate, and they really needed to do an EIR [Environmental Impact Review], and we haven’t heard anything since,” Harrington said.
He agreed that the current pumping is having a negative effect on the aquifer, and said that the County intends to make the case to the DWP that the area can’t sustain more pumping until that groundwater is recovered.
“The Coso project has been anchored on this idea that we don’t want to reduce surface water available to Little Lake by 10 percent,” he said, “… So we’ll do our best to hold the LADWP to the same standard. That’s always a challenge.”
Arnold told the Board that while Little Lake has grave concerns about the DWP project, “We’ve gained a great deal of trust with Coso and the County during the last few years and we are not quite as paranoid as we were seven or eight years ago.”
Coso Geothermal Site Manager Chris Ellis affirmed this improved relationship between Coso and Little Lake, saying, “Coso has always tried to go above and beyond the requirements of the HMMP [Habitat Mitigation and Monitoring Plan]. Even with the decision to allow pumping until June 30, we made the decision to cut our pumping in half from what it was in September … We want to stay ahead of it and only take what is prudent.”
In fact, Ellis said, Coso has never used its entire water allotment. Generally Coso has pumped closer to 1,000 acre feet/year.
“Throughout the process, I think we’ve demonstrated our strong commitment to being environmentally responsible and a good neighbor to other Rose Valley parties,” Ellis said after the hearing. “We’ve voluntarily kept our pumping rates well below the maximum allowed amount in anticipation of low precipitation and will continue to manage the project conscientiously.”
Ultimately the Board of Supervisors voted to deny the appeal, a decision Arnold said “was not unexpected.”
“While I appreciate the discretion that the Water Department has to manage and control the Coso water pumping project, the members of Little Lake Ranch feel it is incumbent upon us to safeguard a vastly important portion of Inyo County, consisting of Little Lake, its habitat and its wildlife,” Arnold said. “We can only continue to express our concerns over the magnitude of pumping and the dangers that it poses to the ecosystem at Little Lake.”