ITC recognizes water is one of Arizona’s most precious resources. Any water use contemplated for the project must be sustainable and consistent with Arizona’s broader social, legal and ecological values. Recognizing the critical value of water to the region, ITC is evaluating the potential impacts of its proposed groundwater withdrawal with the strategic guidance from a leading, respected hydrologist who developed the Northern Arizona Groundwater Flow Model and input from a stakeholder water work group.

Through this stakeholder engagement, we are assessing the project’s viability, addressing our environmental approach and identifying measures to ensure project benefits are realized throughout the region. As part of our commitment to environmental stewardship, we will build the project only if we can do so without adversely impacting the Big Chino Aquifer, Verde River and residential wells.

View Water Fact Sheet

What we know:
  • Approached in the right and responsible way, using water to store and generate electricity will benefit Arizona, and the Southwest, as a whole. The electricity stored at this pumped storage facility will be integrated with transmission lines for delivery to customers across the region.
  • We are engaging with local communities and stakeholders on how best to develop the Project, while protecting the groundwater supply used by residents of the Big Chino area and base flow of the Verde River, including dependent wildlife and habitat.
  • While all water-supply options are currently being considered, we envision withdrawing groundwater as the primary source. We are considering a combination of short-term and long-term strategies to offset impacts to the aquifer, based on sound science and stakeholder input.
  • Hydrogeological modeling is underway with a broad range of Arizona based water professionals, representing local and regional stakeholder groups, to assess the extent and impact of potential groundwater withdrawal.
  • Securing land for the Project will enable us to restrict future uses of water for subdivisions and lot splits by imposing land use restrictions.

About the use of water in this pumped storage facility:

  • Our facility will pump water from a lower reservoir to an upper reservoir during periods of low electrical demand or high variable generation supply (when many of us are away from home), then release the energy during high-demand periods (when most of us are at home). Pumped storage is like a large and flexible electric battery.
  • The project is located within the Big Chino groundwater sub-basin in north-central Arizona.
  • An estimated one-time volume of ~27,000 acre-feet is needed to fill the reservoirs. This includes water used during construction.
  • The water reservoirs would be filled once and work in a closed-loop design. Closed-loop pumped storage projects are not continuously connected to a naturally flowing water feature, meaning no big dams on rivers impacting fish and other aquatic biological resources.
  • Given the current state of design, operations will result in ~925 acre-feet of evaporated loss per year – less than the current ~1,500 acre-feet used annually for agriculture on the existing ranch property. The project team is actively working to minimize the amount of evaporation loss through a variety of means.


Commissioner Tobin to Attend Big Chino Valley Pumped Hydro Energy Storage Project Informational Sessions in Prescott and Phoenix

Feb 27, 2018

Commissioner Andy Tobin thanks ITC Holdings Corp. for the extensive stakeholder meetings being held in Prescott and Phoenix this month. The Big Chino Valley Pumped Storage Project is a state-of-the-art 2,000 megawatt (MW) pumped hydro energy storage facility planned in Yavapai, Coconino, and Mohave counties that is anticipated to greatly boost our state’s energy security and resilience. Earlier this month, Commissioner Andy Tobin proposed the comprehensive Arizona Energy Modernization Plan which includes a target of 3,000 MW of energy storage operating in the state by 2030. READ MORE.