Illinois Flood Maps

Effective Regulatory Products

Effective products are the official regulatory products as adopted by FEMA and a given local community for the National Flood Insurance Program (NFIP). The products are intended to be used as the basis for official actions required by the NFIP. The products may include Flood Insurance Rate Maps (FIRM), Flood Insurance Study (FIS) reports, FIRM Databases, and effective Letters of Map Change (LOMC).

Effective Flood Insurance Rate Maps for McHenry County may be viewed and/or downloaded at the FEMA Flood Map Service Center (MSC).

Additionally, effective flood hazard data can be viewed in FEMA's National Flood Hazard Layer viewer (NFHL). Counties with a status of Effective or any of the Physical Map Revision (PMR) statuses (symbolized with diagonal lines) on the Resources by County map are included in the NFHL viewer. Zoom to an area or use the search bar to find a specific location.  Full FIRM panels or a “FIRMette” of a smaller area can be exported using the NFHL Print Tool.

Non-regulatory Products

Non-regulatory products, referred to as Flood Risk Products (FRP), go beyond the basic flood hazard information found in the official regulatory products. The Flood Risk Database, which parallels the FIRM database, provides a wealth of data that may be used to analyze, communicate, and visualize flood risk. Communities are encouraged to use this database to support mitigation efforts and raise awareness. Non-Regulatory products such as Flood Risk Databases are also available at the MSC.