A newly released study—authorized by Congress and jointly funded and prepared by the Department of the Interior’s Bureau of Reclamation and the seven Colorado River Basin states—projects water supply and demand imbalances throughout the Colorado River Basin and adjacent areas over the next 50 years. The Colorado River Basin Water Supply and Demand Study, the first of its kind, also includes a wide array of adaptation and mitigation strategies proposed by stakeholders and the public to address the projected imbalances.
The average imbalance in future supply and demand is projected to be greater than 3.2 million acre-feet by 2060, according to the study. One acre-foot of water is approximately the amount of water used by a single household in a year. The study projects that the largest increase in demand will come from municipal and industrial users, owing to population growth.
The Colorado River Basin currently provides water to some 40 million people, and the study estimates that this number could nearly double to approximately 76.5 million people by 2060, under a rapid growth scenario.
Authorized by the 2009 SECURE Water Act, the study analyzes future water supply and demand scenarios based on factors such as projected changes in climate and varying levels of growth in communities, agriculture and business in the seven Colorado River Basin states of Arizona, California, Colorado, New Mexico, Nevada, Utah, and Wyoming.
The study includes more than 150 proposals from study participants, stakeholders and the public that represent a wide range of potential options to resolve supply and demand imbalances. Proposals include increasing water supply through reuse or desalinization methods, and reducing demand through increased conservation and efficiency efforts.
The scope of the study does not include a decision as to how future imbalances should or will be addressed. Reclamation intends to work with stakeholders to explore in-basin strategies, rather than proposals—such as major trans-basin conveyance systems—that are not considered cost effective or practical.
The study is one of a number of ongoing basin studies that Reclamation is undertaking through Interior’s WaterSMART Program, said Assistant Secretary for Water and Science Anne Castle. WaterSMART is Interior’s sustainable water initiative and focuses on using the best available science to improve water conservation and help water-resource managers identify strategies to narrow the gap between supply and demand.
The WaterSMART program includes Reclamation’s Water and Energy Efficiency grants, Title XVI Reclamation and Recycling projects, and USGS’s Water Availability and Use Initiative.
Spanning parts of the seven states, the Colorado River Basin is one of the most critical sources of water in the western United States. The Colorado River and its tributaries provide water to about 40 million people for municipal use; supply water used to irrigate nearly 4 million acres of land, and is also the lifeblood for at least 22 Native American tribes, 7 National Wildlife Refuges, 4 National Recreation Areas, and 11 National Parks. Hydropower facilities along the Colorado River provide more than 4,200 megawatts of generating capacity, helping meet the power needs of the West.
Throughout the course of the three-year study, eight interim reports were published to reflect technical developments and public input. Public comments are encouraged on the final study over the next 90 days; comments will be summarized and posted to the website for consideration in future basin planning activities.