Oldham County, KY Environmental Rules: Stormwater Management (2026)

Chapter 154, Post-Construction Stormwater, Pollutants and Sediment, governs stormwater management in unincorporated Oldham County and in any incorporated area that is a co-permittee on the county's KPDES MS4 permit (§ 154.01). Under § 154.03, any new development or redevelopment disturbing one acre or more, or part of a larger common plan disturbing an acre or more, must submit a stormwater management plan to the County Engineer before construction, sealed by a Kentucky-licensed professional engineer, and obtain a soil and erosion control permit. Design criteria in § 154.05 require the ten-year storm for public storm sewers and channels, the 100-year storm as a check, and post-development peak flow rates held at or below pre-development rates for the two-year, ten-year and 100-year storms.

Green infrastructure BMPs must capture the water quality volume from the 80th percentile precipitation event, equivalent to 0.6 inches of rainfall, and drain within 48 hours. Every stormwater facility must be covered by a recorded maintenance agreement running with the land, binding successors and any homeowners association, per § 154.09, and easements permitting county inspection must be granted and recorded with the County Clerk.