Tazewell County, IL Environmental Rules: Flood Elevation Requirements (2026)

Chapter 152 of the Tazewell County Code sets the county's flood protection standard above the federally mapped 1% annual chance base flood. 02 defines the FLOOD PROTECTION ELEVATION (FPE) as the base flood elevation (BFE) plus two feet of freeboard, the buffer required to absorb calculation uncertainty, future watershed development and unpredictable effects like ice or debris jams. In an AO Zone the FPE is instead the mapped depth plus one foot, or a higher standard of two or three feet chosen by the county; where an AO Zone carries no mapped elevation, the lowest floor must sit at least one foot, or a chosen two or three feet, above the highest adjacent natural grade.

06 makes the FPE the operative construction standard: any building located in the floodplain, whether newly built, substantially improved (50% or more of market value, or a 20% floor-area increase, cumulative over ten years), substantially repaired after flood damage, or a manufactured home or long-term recreational vehicle placement, must be protected below the FPE. An owner can meet that by building on permanent fill with the lowest floor, including basement, at or above the FPE (with fill placed in six-inch compacted lifts, extending at least 20 feet beyond the foundation, and protected against erosion), or by elevating the building on stilts, piles, solid walls or an open crawlspace so the lowest floor and all electrical, heating, plumbing and HVAC equipment sit at or above the FPE.

03, uses the county's FEMA Flood Insurance Study and the FIRM panels dated July 21, 2026 to fix the BFE for each parcel, and requires anyone disputing that data to fund the engineering study needed to challenge it before any development proceeds.