Brockton, MA Environmental Rules: Stormwater Management (2026)

Brockton's Stormwater Management Manual, City Code §§ 23-151 through 23-167, applies to every site plan, subdivision, grading or land-use conversion application that increases stormwater runoff or alters a parcel's drainage characteristics under § 23-154(a). Covered projects must obtain both a Stormwater Management Permit and a Land Disturbance Permit from the Stormwater Authority before any site work begins; performing regulated disturbance without filing an application is itself a violation under § 23-158(b)(2). Limited exemptions cover normal agricultural land maintenance, routine lawn and garden upkeep, and single-family houses under a quarter acre that instead get administrative review under § 23-154(b).

Design standards sit in § 23-159. Structural stormwater practices must remove 80 percent of average annual post-development total suspended solids, sized to a water quality volume of 0.50 inches times the site's total impervious area, rising to 1.0 inches in critical areas, under § 23-159(g)-(h). Channel protection requires holding the two-year storm peak discharge to pre-development rates, overbank flood protection is measured against the 10-year, 24-hour storm, and extreme flood review uses the 100-year, 24-hour storm under § 23-159(c)-(e). The Stormwater Authority inspects projects at initial site review, erosion-control setup, and rough and final grading, and issues a Certificate of Completion only after an as-built inspection confirms the system performs in an actual storm under §§ 23-163 and 23-164.

Enforcement runs through § 23-166. The Authority can issue cease-and-desist orders, require repair of the stormwater system, and recover abatement costs as a lien on the property.