Bonneville County, ID Environmental Rules: Boat Dock Permits (2026)

Section 154.27 requires a floodplain development permit before the commencement of any development activity within a special flood hazard area, and § 154.28(B)(1) spells out that "docks" fall within the development the permit covers, listed alongside houses, garages, pools, bulkheads and grading work. To apply, the owner submits a plot plan showing the dock's location, dimensions and elevation, the special flood hazard area boundary from the FIRM, the base flood elevation where established, and certification of the plot by a registered land surveyor or professional engineer, per § 154.28(A).

If the dock sits in a mapped regulatory floodway rather than just the broader flood hazard area, § 154.49(B) adds a stricter layer: no encroachment, including new construction, is permitted unless the owner demonstrates through hydrologic and hydraulic analysis that it causes no rise in base flood levels, or FEMA has approved a conditional letter of map revision. Division (B)(4)(e) of that same section names docks specifically: "Docks, piers, boat ramps, marinas, moorings, decks, docking facilities, port facilities, shipbuilding and ship repair facilities that encroach into regulated floodways shall meet the limitations of this section." Separately, § 50.19(B) requires that every dock servicing watercraft in the county have conveniently located toilet facilities for men and women and covered garbage and waste facilities, tying dock use to the county's water pollution rules banning discharge of sewage or refuse from watercraft into county waters.

On the Ririe (Blacktail) and Palisades Reservoirs, § 72.21 further sets no-wake buffers within 100 feet of boat docks and floating docks, a separate navigation-safety rule enforced by county deputies under § 72.22.