Groundwater pumping and the effects on wildlife habitat are not new controversies in the Eastern Sierra. Now, the plan to pump water from the Hay Ranch area up to the Coso Geothermal Power Plant has members of the Little Lake Duck Club concerned with water exports and the loss of wetland wildlife habitat.
In this case, renewable geothermal power is pitted against wildlife habitat in a battle of conflicting environmental goals. The power plant operators feel there is room for both.
We recently spoke with officials from Terra-Gen, the parent company of the Coso Geothermal operations about this situation.
Company officials explained that the Coso plants use hot water from wells as deep as 13,000 feet to turn the turbines that generate power. Currently Coso Power has 9 turbines at three sites which produce about 205 megawatts. The amount of power that the plant can produce is down in recent years from a high of 270 megawatts. More water is needed to boost power production, according to Coso officials.
Much of the hot water from underground is re-injected into the earth, but some comes out of the ground as steam. In order to turn the steam back into water to be re-injected into the earth, the steam is cooled by swamp cooler like evaporative coolers. These coolers lead to the water loss in the system.
With the loss of water greater then the natural groundwater recharge under the plant, the idea is to bring more water to the site to supplement the groundwater. Currently, the plan is to pump 4800 acre feet of water per year from the Hay Ranch up to the power plant.
The plan to pump water from the ranch just south of the Haiwee Reservoir has left members of the Little Lake Duck Club concerned for the future of the wetlands on their property. In comments on the draft environmental documents, the lawyers for the Little Lake Duck Club lay out concerns that the proposed pumping plan will lead to a 10% loss of water at the duck club property downstream. The comments state that no one should suffer any loss of water because of the project.
Right now the plan is to drill seven monitoring wells to watch what happens to the ground water level if the pumping is allowed to start. Company officials say that if the groundwater levels drop, the pumping will either be reduced or it will stop.
Officials with the geothermal company hope to have the water project underway this spring. For that to happen, the Inyo Water Commission has to sign off on the plan. Then it would go to the Planning Commission for approval. If either side is not happy with that outcome, they can appeal to the Board of Supervisors.