On July 21, 2022, new Ohio law governing regulation of ephemeral streams went into effect.  The new law is the result of House Bill 175, which was passed by the Ohio General Assembly on April 6, 2022.  With this legislation, the definition of “Waters of the State” set forth in Ohio law was changed to now exclude those ephemeral features that are not also federally jurisdictional, as determined by the U.S. Army Corps of Engineers.  For those ephemeral features that are federally jurisdictional, Ohio law now sets forth best management practices (BMPs), mitigation and restoration requirements, performance standards, and monitoring and reporting requirements to be included in Ohio EPA’s issuance of Section 401 Water Quality Certifications.

Ohio’s mitigation requirements apply only to streams classified as jurisdictional by the U.S. Army Corps of Engineers and impacted above 3/100 acres (1,306 square feet).  The area of mitigation required is determined by a calculation that considers both the width of the streamway and the slope of the stream.  The new provisions further set forth five mitigation options for permanent impacts to ephemeral streams and provide detailed restoration requirements for temporary impacts to ephemeral streams.  To aid applicants for Section 401 Water Quality Certifications proposing impacts to ephemeral streams, Ohio EPA has issued a Guidance Document as well as an Ephemeral Stream Mitigation Calculator.

Ohio EPA also issued Findings and Orders (effective July 21, 2022) terminating Ohio EPA’s Level 1 Isolated Wetland and Ephemeral Stream General Permit, which previously authorized impacts to those ephemeral streams that were not federally jurisdictional but were regulated under state law.  In its place, Ohio EPA has issued a 2022 Level 1 Isolated Wetland General Permit, which governs impacts to those wetlands that are not federally jurisdictional but continue to be regulated under state law. 

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