Hendricks County, IN Environmental Rules: Stormwater Management (2026)

001 adopts the ordinance under home-rule authority and federal Clean Water Act Phase II NPDES requirements, regulating discharges, drainage improvements, erosion and sediment control, dam construction, and development within floodways and floodplains. 002 requires that no building permit issue and no land disturbance begin for any development until the county has accepted the required plans in writing, though single-family homes in accepted subdivisions, additions under 500 square feet, and disturbances under 5,000 square feet are exempt from most (not all) of the chapter's requirements, and agricultural land-disturbing activity is fully exempt.

021 prohibits discharging or illegally dumping anything but stormwater or an exempted discharge into an MS4 conveyance, watercourse, or waterbody, and requires dischargers to use best management practices to minimize pollutants. 024 places an affirmative duty on property owners through whom a watercourse passes to keep that portion free of trash, debris, and obstacles, and to maintain structures near the watercourse so they don't become a hazard. 041 requires detention and controlled release of excess runoff for all developments and redevelopments, since local streams lack capacity for continued urbanization, with detailed release-rate standards set in the county's Stormwater Technical Standards Manual.

111: the county issues a written notice of violation detailing findings and required remedial actions, may impose compensatory actions like creek cleanup in lieu of penalties, and can issue stop-work orders, with a 72-hour cure period specifically for erosion-control inadequacies on SWPPP-approved construction projects unless a health or safety hazard is involved.