Canyon County, ID Environmental Rules: Flood Zones (2026)

Canyon County Code § 07-10A-05, 'General Provisions,' anchors the county's floodplain overlay in Article 10A of Chapter 7. Subsection (2) adopts, by reference, the Federal Insurance Administrator's 'Flood Insurance Study (FIS) for Canyon County, Idaho, and Incorporated Areas,' dated June 7, 2019, along with its accompanying Flood Insurance Rate Maps (FIRM) and Digital FIRMs, kept on file at the Development Services Department office at 111 North 11th Avenue in Caldwell. Subsection (3) then requires a floodplain development permit before any development activity begins within those mapped special flood hazard areas, with the application and certification process spelled out in § 07-10A-09.

'Development' is defined broadly at § 07-10A-03 to include mining, dredging, filling, grading, paving, excavation, drilling and the construction of berms, dikes and levees, so the permit trigger reaches far more than new buildings. The article treats all of its standards as minimum requirements to be construed in the county's favor, and subsection (6) makes clear that where the floodplain rules and any other ordinance, easement or deed restriction conflict, whichever imposes the more stringent restriction controls. Subsection (8) makes it unlawful to fail to comply with any part of the article and ties a conviction to the general penalty at § 01-01-07, while subsection (9) separately authorizes the county to pursue civil enforcement under § 07-19-01 when the Board finds an imminent threat to human health or safety, independent of the criminal remedy.

None of Article 10A reaches property inside Caldwell, Nampa or the county's other incorporated cities, each of which administers its own floodplain program under its own code.