On navigable Idaho lakes, docks, piers, pilings, floats, boat ramps, breakwaters and similar structures are ‘encroachments’ regulated by the Idaho Department of Lands (IDL) under the Idaho Lake Protection Act (Idaho Code Title 58, Chapter 13, titled ‘Navigational Encroachments’). Building a new one — or materially modifying an existing one — requires an IDL encroachment permit; single-family noncommercial docks follow a streamlined process, while larger, commercial, or non-navigational encroachments require public notice and a hearing. Importantly, a permit doesn’t automatically pass with the property: when waterfront property sells, the existing dock’s permit must be formally reassigned to the new owner through IDL (a separate request and fee). Before buying waterfront property with a dock, confirm the dock is permitted and find out what’s required to transfer that permit into your name.