Johnston County, NC Landscaping Rules: Rainwater Harvesting (2026)

Johnston County has no landscaping ordinance dedicated to rain barrels or cisterns as such. Instead, rainwater harvesting is folded into the county's stormwater management article as one of the recognized 'primary stormwater control measures' (SCMs) listed in § 14-384, alongside wet ponds, stormwater wetlands, infiltration systems, sand filters, bioretention cells, permeable pavement and green roofs. To count toward a development's required stormwater control, a rainwater harvesting system must be designed, constructed and maintained according to the North Carolina Department of Environmental Quality's Minimum Design Criteria (MDC), not a generic rain-barrel standard.

Using rainwater harvesting as a primary SCM pulls the installation into the rest of the stormwater article. Under § 14-389, the property first needs an approved stormwater permit before land-disturbing activity begins, and the permit will not issue until the stormwater administrator approves the management plan, any required easements are recorded, and an inspection and maintenance agreement is on file. Under § 14-394, the owner of the harvesting system must execute a recorded operation and maintenance agreement running with the land, covering repair and reconstruction obligations, and must submit an annual inspection report from a registered engineer, landscape architect, or an NC State University Cooperative Extension-certified inspector describing the SCM's condition with photographs.

Section 14-387's quantity controls set the attenuation targets a harvesting system may help meet: one-year through 100-year storm events in the Environmentally Sensitive area district and Middle Creek Watershed, one-year through 25-year events elsewhere, unless the small-lot exemptions in § 14-387(b)(3) apply. Failing to maintain an approved SCM, including a rainwater harvesting system, is enforced the same as any other stormwater violation under § 14-399.