Ottawa County, MI Environmental Rules: Flood Zones (2026)

Article VIII of the Ottawa County Environmental Health Regulations governs on-site sewage disposal systems for single- and two-family dwellings, and Section H sets nine site acceptance criteria the Health Officer must evaluate before approving construction, repair, enlargement or relocation of a system. Criterion 3 bars any site "located within the ten (10) year flood plain as determined by credible statistical projections, or historical evidence," alongside sites subject to seasonal surface flooding, ponding or heavy runoff. Criterion 9 separately bars filled ground over unacceptable soils such as peat, muck, marl, impervious clay, organic material or solid or hazardous waste.

Soil permeability must extend a minimum two feet below the absorption system, and the seasonal high groundwater table must sit at least six inches beneath the ground surface. If a site fails these tests, the Health Officer denies the permit and states the reason in writing under Article IX. A permit already issued can be voided under Section I if new information shows the site never complied, including violations of the Subdivision Control Act, Act 288 of 1967. Any grading, cutting or filling to overcome a flood-plain or permeability problem needs the Health Officer's prior approval under Section J.

This flood-plain siting bar is separate from the twelve-inch well-cap freeboard rule for water supplies in flood-affected areas found in Article XXIII, Section W, which governs a different component of the same property.