In New Jersey, rainwater is generally considered a resource that property owners can capture and use, particularly for non-potable purposes like irrigation or stormwater management, without state-level restrictions on ownership. The state follows riparian water rights principles for surface waters, granting landowners reasonable use of adjacent waters, but rainwater harvesting is explicitly encouraged by the New Jersey Department of Environmental Protection (NJDEP) as a best management practice.​
Rainwater Harvesting Rules
New Jersey has no statewide rules prohibiting or regulating rainwater harvesting for residential, commercial, or public properties, allowing installation for outdoor non-potable use or groundwater infiltration without fees from local or state agencies. Local authorities may require permits, inspections, or compliance with plumbing codes for systems connected indoors or using spray irrigation, often mandating filtration, overflow pipes to stormwater drains, and approved materials. Potable use is not recommended without treatment and local approval due to health concerns.​
Water Rights Framework
New Jersey adheres to the riparian doctrine, where owners of land bordering natural water bodies have rights to reasonable use of those surface waters, but the state retains ownership of tidelands below mean high tide under the public trust doctrine. For rainwater specifically, no prior appropriation doctrine applies as in western states; it falls under property rights for on-site capture, with NJDEP overseeing larger diversions over 100,000 gallons daily via permits.​
Conservation Laws
NJDEP promotes conservation through stormwater rules emphasizing green infrastructure like rain gardens and cisterns to reduce runoff pollution and flooding. Local ordinances often restrict public water irrigation to odd/even days or specific hours during dry seasons, exempting rainwater or private sources. The Water Supply Management Act requires permits for significant groundwater or surface withdrawals to prevent overuse.
