Kauai County, HI Environmental Rules: Erosion Control (2026)

The Kaua'i County Council titled Article 7 of Chapter 22 the "Sediment and Erosion Control Ordinance" (Sections 22-7.1 to 22-7.27), and its Best Management Practices duty applies to every grading, grubbing and stockpiling project on the island "regardless of whether a permit is required" or an exemption applies (Section 22-7.5). The County Engineer in the Department of Public Works can require drainage controls that route runoff to natural drainage courses, dust suppression through watering, dust fences or limited disturbance areas, retention of natural vegetation wherever feasible, and a defined menu of erosion controls, including staged construction, protective fencing around retained vegetation, covered topsoil stockpiles, check dams, seeding, matting and vehicle wheel-wash stations before trucks leave the site.

Sediment control measures required alongside them include sediment basins and traps, filter-fabric silt fences, straw-bale or gravel-bag barriers, and stabilized construction entrances. Any disturbed area that will sit idle for 21 days or more must be grassed or graveled no later than the 14th day after the last disturbance. Using soil as fill is banned within any shoreline area defined by Hawai'i Revised Statutes Section 205A-41, except for sand as the Article defines it, and grading or mining a coastal dune is banned outright unless the State Board of Land and Natural Resources permits it.

Projects disturbing more than one acre must keep an on-site BMP plan available, and the County Engineer had 180 days from the ordinance's enactment to adopt a full BMP manual under Hawai'i Revised Statutes Chapter 91. Most grading, grubbing or stockpiling still needs a separate permit under Section 22-7.8 unless it falls under a narrow exemption, such as excavation under 100 cubic yards or agricultural operations managed under an approved soil-conservation plan.