Marion, OH Environmental Rules: Stormwater Management (2026)

Chapter 915.5 of the Marion Codified Ordinances governs stormwater quality after construction ends. These are City of Marion rules, not Marion County or Marion Township rules. The chapter applies to development areas with new or relocated projects involving highways, underground cables, pipelines, subdivisions, industrial projects, commercial projects, building activities on farms and redevelopment of urban areas (§ 915.5.3). It does not reach work covered by the Ohio Agricultural Sediment Pollution Abatement Rules, linear utility projects that add no impervious surface, or transportation projects subject to industry-specific Ohio EPA rules.

Under § 915.5.4 the plan must name the person or entity responsible for maintaining every vegetative or mechanical best management practice (BMP). A site that disturbs one (1) or more but less than five (5) acres must describe the BMPs that will control pollutants after construction. A site that disturbs five (5) or more acres, or is part of a larger common plan that will, must detain runoff, build structural BMPs into the permanent drainage system, and size them to treat the water quality volume, which the code sets as the runoff from a 0.75-inch rainfall.

Maintenance is a perpetual duty. In single-family developments a Homeowners' Association must be created and carry the inspections and upkeep. Multi-family, commercial and industrial owners carry them directly. Both stay responsible unless the City of Marion officially accepts the work. One (1) inspection with a written report is required each year, due to the City Engineer by May 1st. Easements to reach the BMPs must be at least twenty-five (25) feet wide in addition to the ditch or channel, and they bar woody plantings, buildings, fences and walls.

Permanent stormwater practices must be built before Final Plat Approval, or deferred for no more than six (6) months under a bond, escrow, verified check or cash guarantee (§ 915.5.7). The performance guarantee is not less than 120% of the City Engineer's estimate. The maintenance guarantee is 20% of the estimate and runs not less than two (2) years after final acceptance. Approved plans remain valid for two (2) years (§ 915.5.8).