Durham, NC Landscaping Rules: Rainwater Harvesting (2026)

Rainwater harvesting in Durham is governed primarily by North Carolina state law rather than local ordinance. In 2009, the N.C. Legislature passed State Law 243, which amended the plumbing code to facilitate residential and commercial cistern use and explicitly prevents any state, county, or local building code from prohibiting cisterns for these applications. A companion provision under N.C.G.S. Chapter 153A states that no county ordinance may prohibit the installation and maintenance of cisterns and rain barrel collection systems used for irrigation, though counties may regulate installation to protect public health and safety and prevent public nuisance conditions such as standing water that breeds mosquitoes. In Durham, rainwater collection systems are exempt from the mandatory odd-even watering schedule, providing a significant practical incentive for installation. Residential rain barrels typically hold about 60 gallons and connect to downspout diverters. Larger residential cisterns can store several hundred to several thousand gallons. Untreated harvested rainwater is approved for outdoor irrigation, decorative fountains, vehicle washing, and outdoor hose bibs. With appropriate filtration and treatment, rainwater may also be used indoors for toilet and urinal flushing, trap primers, fire suppression systems, clothes washers, and residential hose bibs. The NC Department of Environmental Quality encourages rainwater harvesting as a water conservation best practice and a stormwater management credit. Durham County does not impose any registration or permit requirement for standard residential rain barrels, though larger cistern installations that modify plumbing may require a building permit. Homeowners should ensure rain barrels have screens to prevent mosquito breeding and are secured to prevent tipping.