Holgate

Henry County's dominant cross-county overlay is FEMA NFIP floodplain regulation along the Maumee River corridor, which bisects the county roughly west-to-east through Damascus, Napoleon, Flatrock, and Washington Townships and through the City of Napoleon. The 2024 Henry County Hazard Mitigation Plan reports that roughly 3.2 to 3.75 percent of the county's total acreage - about 8,624 to 10,000 acres - sits in the 100-year floodplain or flood hazard area. The county participates in the National Flood Insurance Program and the Henry County Planning Commission director serves as the county floodplain manager, issuing floodplain development permits for unincorporated SFHA parcels and coordinating with the City of Napoleon and the villages on their municipal NFIP compliance. There is no countywide coastal overlay (Henry is inland), no wildland-urban-interface fire overlay, and no countywide historic-preservation overlay. The second large operational overlay is agricultural-use enrollment under CAUV (ORC 5713), which covers a substantial share of unincorporated parcels given Henry County's predominantly-agricultural land use - any ADU on a CAUV parcel needs to address the homesite-area expansion and three-year recoupment exposure with the Auditor. A third county-wide regulatory feature, distinct from a zoning overlay but operationally significant for any new dwelling, is the Henry County Health Department's five-year HSTS Operation and Maintenance Program adopted in spring 2023, which is being phased in by township groups (Liberty and Napoleon Townships scheduled October 2025 to September 2026); any ADU using a new or existing septic system will be in scope.

• FEMA NFIP Special Flood Hazard Areas along the Maumee River corridor in Henry County — Critical facilities must be sited outside the SFHA when feasible. Letter of Map Amendment (LOMA) and Letter of Map Revision (LOMR) processes can adjust effective mapping for parcels with verified higher ground elevations. The Henry County Engineer maintains downloadable FEMA 100-year flood GIS layers on request.
• Agricultural-use parcels under CAUV (Current Agricultural Use Value) — ADU applicants on CAUV-enrolled parcels should consult the Henry County Auditor (419-592-1956) before construction to confirm homesite-area treatment and quantify recoupment exposure.
• Henry County HSTS Operation and Maintenance Program (five-year septic operation permits) — ADUs on parcels with public sewer (primarily inside the City of Napoleon and certain villages) are not subject to the HSTS program. The county maintains a list of approved STS service providers.

Permit responsibility in unincorporated Henry County is split across the township zoning inspector network, the state residential building program, the county planning commission's floodplain function, and the county health department. (1) Township zoning permits for residential construction (including ADUs as accessory residential structures, where allowed) are issued by the zoning inspector of the township the parcel sits in. Henry County's zoning-inspector roster (as posted by the Henry County Planning Department) shows each of the thirteen townships with an assigned inspector: Bartlow (Evan Geno), Damascus (Andrew Rehner), Flatrock (Henry County Planning, contract), Freedom (Kim VanValkenburg), Harrison (Laura Bishoff), Liberty (Henry County Planning, contract), Marion (Peter Willhelm), Monroe (Darvin Biederstedt), Napoleon (Henry County Planning, contract), Pleasant (Pete Giesige), Richfield (Evan Geno), Ridgeville (Eric Rohrs), Washington (Brad Meister). The county planning office serves as the zoning inspector under contract for Flatrock, Liberty, and Napoleon Townships. (2) Residential building permits under the Ohio Residential Code (RCO) for one-, two-, and three-family dwellings in unincorporated Henry County are administered through the Ohio Department of Commerce / state residential building program rather than a county-staffed building department; Henry County does not maintain a certified residential building department of its own. (3) Floodplain development permits in unincorporated Henry County are issued by the Henry County Planning Commission, whose director serves as the county floodplain manager. (4) On-site sewage permits (Household Sewage Treatment Systems) are issued by the Henry County Health Department (1843 Oakwood Avenue, Napoleon) under Ohio Administrative Code 3701-29; HSTSs are also entering a five-year operation-and-maintenance permit cycle by township groups (Liberty and Napoleon Townships scheduled for October 2025 to September 2026). (5) Driveway access permits onto county roads are issued by the Henry County Engineer. An ADU project in unincorporated Henry County therefore typically requires: a township zoning permit (where the township has zoning that permits or conditionally permits ADUs), a state-program residential building permit, a county floodplain development permit if the parcel is in a FEMA SFHA (the Maumee River corridor through the county is the main one), an HSTS install permit and operation permit where no public sewer is available, an engineer driveway permit if applicable, and an address assignment.