Warwick, RI Environmental Rules: Stormwater Management (2026)

Section 68-2 ties Warwick's stormwater rules to the Rhode Island Department of Environmental Management's RIPDES general permit for small municipal separate storm sewer systems (MS4s), since untreated runoff carries suspended solids, nitrogen, phosphorus, hydrocarbons, and road salts into local waters. Section 68-8 requires every applicant to submit a stormwater management plan prepared by a professional engineer licensed in Rhode Island, built to the Rhode Island Storm Water Design and Installation Standards Manual and the Rhode Island Soil Erosion and Sediment Control Handbook. Plans must control post-development peak discharge rates for the 2-year, 10-year, 25-year, and 100-year storm events at pre-development levels, analyze downstream impacts of the 100-year event, and size conveyance systems to handle at least a 25-year storm without erosive flows.

Under Section 68-9, applicants must calculate sub-watershed areas, impervious surface totals, curve numbers, and pre- and post-development discharge rates for each storm frequency. Section 68-13 requires a recorded maintenance agreement for every stormwater facility not dedicated to the city, listing the responsible party and maintenance schedule, and Section 68-13(d) gives the director of public works and building inspector a right of entry to inspect facilities on private property. Section 68-11 further authorizes the city to inspect any best management practice built after the chapter's 2016 enactment to confirm it matches the approved plan.