From the last half of the 20th century, the U.S. has enjoyed nearly universal access to abundant supplies of potable water. But as witnessed by the recent serious and sustained droughts in the Southeast and Southwest, this past luxury is not something that can be expected for the long term. Future population growth will exert more demand on water systems while climate change is predicted to decrease available supplies because of decreased snow pack and drier regional climatic patterns. The U.S. has been identified as a country that faces imminent water shortages and a Government Accountability Office (GAO) survey found that water managers in 36 states anticipate water shortages during the first two decades of this century. These challenges will require a more sustainable approach to using water resources, looking at not only how much water is used, but also the quality of water needed for each use.

"December 2008." "EPA-833-F-08-010"

This chapter addresses harvesting principles, designs, example code requirements, and policies and incentives of implementing a municipal rainwater harvesting program. Rainwater harvesting can reduce stormwater runoff, conserve potable water, and provide environmental and economic benefits. Barriers to implementation are also addressed, and case studies from across the country demonstrate successful rainwater harvesting programs.