Anchorage, AK Environmental Rules: Coastal Development (2026)
Key Facts
- Setback distance
- 25 feet from ordinary high water mark
- Marine OHWM equals
- the mean high water line
- Applies to
- all zoning districts, all development
- Administering unit
- Watershed Management Services
- Allowed in setback
- boathouses/floatplane storage under 500 sf
- Violation remedy
- restoration plus native revegetation, same season
Summary
Anchorage has no standalone coastal development permit, but AMC 21.07.020B.11 sets a 25-foot setback from the ordinary high water mark for every water body in the municipality, and the code defines that mark as the mean high water line on a marine shoreline, reaching Cook Inlet and Turnagain Arm.
All water bodies shall have setbacks. Buildings, accessory structures, and other impervious surfaces shall be set back at least 25 feet horizontally from the ordinary high water mark of water bodies, except as allowed below. When wetlands are present and contiguous to the water body, additional setback requirements are listed in the Anchorage Wetlands Management Plan. ... "Ordinary high water mark (OHWM)." The line on a shore or bank of a body of water established by the normal fluctuations of water and indicated by a relatively abrupt change in observable physical, hydrologic, and biologic characteristics above and below the line. For a stream or lake the OHWM is approximately equivalent to the "bank." For a marine shoreline, the OHWM is approximately equivalent to the "mean high water line."
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: rev 5010260; v11 updated 2026-09-01).
Full Breakdown
020, Natural Resource Protection, opens by naming "scenic features such as mountains and coastal areas" among the amenities the chapter protects, then applies its watercourse, water body, and wetland standards to all zoning districts and all development in the municipality unless a section of Title 21 exempts it. a requires buildings, accessory structures, and other impervious surfaces to sit back at least 25 feet horizontally from the ordinary high water mark (OHWM) of any water body. 15's definitions make clear this reaches the coastline: for a marine shoreline the OHWM is "approximately equivalent to the mean high water line," as distinct from the streambank measure used for rivers and lakes.
Watershed Management Services, within the Anchorage Planning Department, administers the setback and can authorize limited uses inside it: water-related accessory structures under 500 square feet such as boathouses or floatplane storage, minimal access areas for docks, municipal beaches, and fishing or wildlife-viewing platforms. S. b and c. The section also cross-references the Anchorage Wetlands Management Plan for added setback requirements where coastal wetlands are contiguous to the water body.
Violations & Fines
AMC 21.07.020B.14 requires that any confirmed violation of the water body setback be corrected through restoration approved by Watershed Management Services, with all disturbed areas revegetated using non-invasive trees, shrubs, and ground cover matching the surrounding natural vegetation, during the same growing season as the disturbance. Because the setback sits in Title 21, ongoing zoning violations are also subject to Chapter 21.14 enforcement, including stop-work orders and civil penalties.
Frequently Asked Questions
Does Anchorage require a special coastal development permit for building near Cook Inlet or Turnagain Arm?
Can I build a boathouse or floatplane hangar within the 25-foot coastal setback?
What happens if I clear vegetation or build too close to the Anchorage shoreline?
Sources & Official References
Other rules in Anchorage
Compare Anchorage to another location·View the Alaska environmental rules overview
See something wrong?
Help us keep this page accurate. If you notice an error or outdated information, let us know.