Consensus Report

Using Graywater and Stormwater to Enhance Local Water Supplies: An Assessment of Risks, Costs, and Benefits (2015)

Each report is produced by a committee of experts selected by the Academy to address a particular statement of task and is subject to a rigorous, independent peer review; while the reports represent views of the committee, they also are endorsed by the Academy. Learn more on our expert consensus reports.

Graywater and stormwater capture and use can expand local water availability while providing additional benefits, such as reduced water pollution (for stormwater) and a drought-resistant year-round water supply (for graywater). Treatment can help address contaminants in the water, but a lack of risk-based treatment guidelines hinders the broader use of stormwater and graywater, this report finds. There is no single best way to use graywater or stormwater to address local water needs, and many important considerations--including legal and regulatory constraints, potential applications, and source water availability--vary widely with local conditions. To address these challenges, this report assesses the risks, costs, and benefits of graywater and stormwater use to augment water supplies.