County-Scale Rainwater Harvesting Feasibility in the United States: Climate, Collection Area, Density, and Reuse Considerations

Mounir William Ennenbach, Paulina Concha Larrauri , and Upmanu Lal

Roof rainwater harvesting has the potential to augment water supplies for urban and suburban uses throughout the United States. Studies of the performance of roof rainwater harvesting at the building and city scales in the U.S. are available, but a countrywide overview of the potential at the county scale has not been done before. This study aims to fill that gap by providing a county-level analysis of the potential of roof-based rainwater harvesting for urban water use in the U.S. by assessing the viability of roof rainwater harvesting as a water resource in each county, evaluating the performance of a “typical” roof rainwater harvesting system in each county, and evaluating the effect of adding a water reuse element to the “typical” roof rainwater harvesting system analysis.