Lake County, IN Environmental Rules: Flood Zones (2026)

Lake County Code Chapter 157 governs development in the floodplain of unincorporated Lake County, adopted by County Council Ordinance 2473 on March 8, 2016 under the zoning authority granted by I.C. 36-7-4. Section 157.025 applies the chapter to all Special Flood Hazard Areas (SFHAs) and known flood-prone areas in the unincorporated county, using the flood elevations, floodways and fringe limits mapped on the Flood Insurance Rate Map of Lake County dated January 18, 2012, and any later FEMA revisions (§ 157.026). Before any development activity, including construction, filling, grading, dredging, mining, drainage work, fence or wall erection, or storage of materials, a landowner must obtain a floodplain development permit from the Floodplain Administrator, a role held by the Lake County Plan Commission's Executive Director and designated staff (§§ 157.027, 157.050).

No structure may be located, extended, converted or structurally altered, and no land or stream may be altered, within an SFHA without full compliance with the chapter (§ 157.028). New construction and substantial improvements must be anchored against flotation and lateral movement, built with flood-resistant materials, and have utilities located above the Flood Protection Grade (§ 157.070). New or substantially improved residential structures, including manufactured homes, must have the lowest floor, including any basement, at or above the FPG, defined as two feet above the base flood elevation; non-residential structures may instead be dry floodproofed to that level (§ 157.071).

Where mapped data and actual ground elevation disagree, the FIRM profile elevation controls, and owners above the base flood elevation and outside the floodway may seek a FEMA Letter of Map Amendment (§ 157.030).