Arlington

Hancock County's operationally significant overlays cluster around (1) FEMA NFIP floodplain regulation along the Blanchard River corridor through central Hancock County (including the Findlay urban area) and along Eagle Creek, Lye Creek, Riley Creek, Ottawa Creek, and other Blanchard tributaries - the Blanchard River basin makes Hancock County one of the highest-flood-exposure interior counties in Ohio, with the 2007 Findlay flood (FEMA-1731-DR) the reference event and a multi-decade Maumee Watershed Conservancy District / City of Findlay / Hancock County / FEMA mitigation program currently in execution (FEMA approved $24M in additional mitigation funding in 2026 for Findlay-area projects); (2) Current Agricultural Use Value (CAUV) enrollment, which covers a substantial share of unincorporated parcels in this agricultural county and creates recoupment exposure when an ADU enlarges a residential homesite on enrolled farmland; (3) township-zoning patchwork itself functioning as a de facto overlay - ten Hancock townships are zoned and seven are not, which fundamentally changes the permit path on a parcel depending on which side of a township line it sits; and (4) the Hancock County Subdivision Regulations administered by HRPC, which apply countywide to land divisions. The county has no coastal overlay (it is inland), no wildland-urban-interface fire overlay, no county-wide historic-preservation overlay, and only limited public-land constraints (the Litzenberg Memorial Woods, Riverbend Recreation Area, and similar Hancock Park District holdings remove some parcels from private ADU development but are not regulatory overlays). The City of Findlay maintains its own floodplain ordinance, historic-preservation board, and zoning code; those are municipal, not county, but the county floodplain regulation aligns with the city's because both implement the same FEMA NFIP framework.

• FEMA NFIP Special Flood Hazard Areas along the Blanchard River, Eagle Creek, Lye Creek, Riley Creek, Ottawa Creek, and tributary corridors in Hancock 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; LOMRs have been frequent in Hancock County as mitigation projects come online.
• Agricultural-use parcels under CAUV (Current Agricultural Use Value) — ADU applicants on CAUV-enrolled parcels should consult the County Auditor (419-424-7820 for CAUV-specific questions) before construction to understand recoupment exposure and to verify which portion of the parcel remains in agricultural use after the ADU is added.
• Hancock County Subdivision Regulations (administered by HRPC) — HRPC also provides advisory zoning support to the townships and villages and administers grants and Community Development Block Grant programs that occasionally fund housing-related projects.

Permit responsibility in unincorporated Hancock County is split across several offices. (1) Township zoning permits for residential construction (including ADUs as accessory residential structures, where the township's resolution allows them) are issued by the zoning inspector of the specific township the parcel sits in - applicants must contact the township inspector directly in the ten zoned townships (Amanda, Cass, Delaware, Eagle, Jackson, Liberty, Marion, Portage, Van Buren, Washington). In the seven unzoned townships (Allen, Biglick, Blanchard, Madison, Orange, Pleasant, Union) there is no township zoning permit step at all, but state building code, FEMA floodplain regulation, and septic/well requirements still apply. (2) Residential building permits under the Ohio Residential Code (RCO) for one-, two-, and three-family dwellings in unincorporated Hancock County are issued by the Hancock County Building Department, which is a certified residential building department under ORC Chapter 3781 located at the Hancock County offices in Findlay. The Hancock County BD also serves as the building department of record for several small villages (including Arlington) that do not maintain their own certified residential building department. (3) Floodplain development permits in unincorporated Hancock County are administered by the county floodplain administrator under the county's participation in the National Flood Insurance Program - the Blanchard River corridor through central Hancock County (including the Findlay urban area), Eagle Creek along the south of the county, Lye Creek, and the Riley Creek and Ottawa Creek tributaries create the most significant FEMA Special Flood Hazard Area exposure in the state outside the Lake Erie corridor. (4) On-site sewage approval is administered by the Hancock County Public Health Department where no public sewer is available; septic review is one of the more time-consuming steps for an ADU added to a parcel served by an existing system because soil-suitability and reserve-area requirements may force system upgrades. (5) Driveway access permits onto county roads are issued by the Hancock County Engineer's office at 300 South Main Street in Findlay. (6) Subdivision and lot-split review is administered by the Hancock Regional Planning Commission for any project that depends on creating a new parcel. An ADU project in unincorporated Hancock County therefore typically requires: a township zoning permit (in a zoned township), a Hancock County BD residential building permit, a county floodplain development permit if the parcel is in a FEMA SFHA along the Blanchard River or its tributaries, on-site sewage approval, a driveway access permit if access is from a county road, and HRPC lot-split or subdivision review where applicable.