New Hampshire Rainwater Harvesting Encouraged Statewide

New Hampshire RSA 485-C:6-a establishes that rainwater harvesting is permissible statewide and that captured rainwater may be used for non-potable purposes such as landscaping irrigation, vehicle washing, and toilet flushing. The state encourages conservation and treats rainwater as a beneficial water resource rather than a regulated discharge. Municipalities cannot impose outright bans on residential rain barrels or cisterns, though they retain authority over building code aspects of larger storage systems. Plumbing connections to potable water systems must comply with cross-connection control rules. The Department of Environmental Services provides guidance documents supporting harvesting practices for homeowners.

Improper cross-connections to potable supply may violate plumbing code; non-compliant large cisterns may face building permit enforcement, but simple rain barrels are unrestricted statewide.