By various estimates, a professionally installed rainwater harvesting system for a new single-family home could run between $3,000 and $10,000, the storage tank being the highest cost. On a per gallon basis, this cost can range from about $0.5 for a fiberglass tank to more than $4 for a welded steel tank. A highly sophisticated system serving a large industrial facility may cost well over $100,000 to engineer and construct.
Determining the return on investment for a RWH system also will depend greatly on the services your RW will be providing, how you quantify those benefits, the unit cost of the water it will be replacing, and other factors unique to each individual project. Please refer to our sector pages, as well as RWH Best Management Practices and Demonstration Projects.