Casa Diablo IV Project

The project area is east of the town of Mammoth Lakes in Mono County, California.  The proposed Casa Diablo IV (CD IV) power plant will be located east of U.S. Highway 395 and north of the existing plants at Casa Diablo. The power plant and well field will be located on public lands managed by the U.S. Forest Service (USFS), U.S. Department of Agriculture.  While the USFS manages the surface lands of the project area, the U.S. Bureau of Land Management (BLM), U.S. Department of the Interior manages the geothermal resource.  CD IV is estimated at 30 MW net and will be a binary power plant composed of two Ormat Energy Converters using geothermal fluid that is already being pumped from the geothermal well field in Basalt Canyon. The additional power will be sold to a utility company. This project will supply enough electricity for more than 22,500 homes.

Drilling of a slim hole in Basalt Canyon in 2002. The production wells that are currently producing geothermal fluid will be redirected to be used in the CD IV expansion project.

Ormat's Battle against Geothermal Misconceptions

  • After nearly three years of collaboration with the Bureau of Land Management (BLM), Mammoth Community Water District (MCWD), and the U.S. Geological Survey (USGS), Ormat is happy to announce the approval of a Groundwater Monitoring and Response Plan (GMRP) for the Casa Diablo IV (CD-IV) geothermal plant.  The GMRP, which was approved by the BLM on January 13, is the final permitting step for the plant.  As a member of the community for more than 30 years, Ormat has continually sought to ensure the safe water supply for the Town of Mammoth Lakes and will continue to do so.  The safety of the Mammoth community’s groundwater is a key priority for Ormat and this plan has measures in place to make certain it is protected.  Ormat would like to thank all those involved in developing the GMRP for their contributions
  • See an engaging animation about the dispute between Ormat and Mammoth Community Water District here
  • For a full report on the CD IV project, please click here to access the Environmental Impact Statement by the BLM
  • For current activity in the Long Valley Caldera monitored by the USGS, please click here
  • To learn more about CD IV Project dispute information click here
  • To see the Mammoth Times article about CD IV published July 2, 2015  click here
  • To see the BLM Press Release from July 29, 2015 regarding the monitor well drilling click here
  • To see Ormat’s summary of the "lawsuits" click here
  • Read Ormat's CD IV Monitoring and Response Plan here
  • To see The Sheet news story about CD IV published July 10, 2015 please click here