On August 13, 2018, the Central Arizona Water Conservation District (“CAWCD”) issued a Request for Proposal for Binational Study of Water Desalination Opportunities in the Sea of Cortez (“RFP). CAWCD is interested in participating in the binational process because of the imminent threat of a Lower Basin shortage. The most recent Colorado River Simulation System (“CRSS”) 5-Year Projection by the Bureau of Reclamation shows a 57% chance of a Lower Basin shortage in 2020.
CAWCD has several goals for participation in the binational process, including:
- Seeking voluntary shortage sharing agreements with Mexico to decrease the duration and magnitude of shortages
- Developing and implementing conservation projects in Mexico that lead to more water being stored in Lake Mead
- Avoiding reductions in Arizona return flows during conservation and shortage conditions by managing salinity
- Implementing projects that generate CAWCD Intention Created Surplus (“ICS”) and exploring binational desalination project to augment their own water supplies
The desalination study would be complete under terms of Minute 323, includes a section identifying opportunities for new water supplies projects, including a binational desalination plant at the Pacific Ocean coast, the Sea of Cortez, or the New River and reuse of effluent in Mexico from wastewater treatment plants in the Mexicali Valley in Mexico and in the United States from the South Bay International Wastewater Treatment Plant. Minute 323 also directed the creation of a Binational Desalination Work Group, which was tasked to develop a scope of work to study desalination opportunities in the Sea of Cortez.
The scope of work includes four major tasks:
- Identifying current and unmet demands in Sonora and Baja California, Mexico and in the Lower Colorado River Basin in the United States;
- Identifying desalination technologies that would be applicable to the region;
- Examining potential desalination opportunities and delivery concepts along the 218.8 km (approximately 136 mile) stretch of the Sonoran coast from Rocky Point to Puerto Libertad; and
- Identifying possible environmental impacts on the marine environment, flora, and fauna.
The Work Group, which is co-chaired by members from the State of Arizona and Sonora and includes members from federal agencies in the U.S. and Mexico, as well as from Nevada, California, and Arizona, will serve as study managers. CAWCD will serve as the contract administrator and work to secure funding from parties in Arizona, California, and Nevada. A funding agreement is expected to be completed this fall, and the study process is expected to take 18 months.
CAWCD held a proposal conference on August 28, 2018. Questions related to the RFP were due on September 5, 2018, and proposals on September 19, 2018. Next steps include selection of the consultant by the study management team, approval of the contributed funding agreement by CAWCD, and kickoff of the study.
The desalination opportunities in the Sea of Cortez is the first area that the Work Group is exploring for “new water sources projects” under Minute 323. Additional investigations will be conducted for the Pacific Coast, New River, wastewater plants in the Mexicali Valley, and the South Bay International Wastewater Treatment Plant.
Written by Marta L. Weismann