Watershed Management


The Municipality regulates storm water management at private construction sites under Anchorage Municipal Code Title 21. The Municipality also regulates storm water management during construction of its own (public) projects through Section 20.02 of its Standard Specifications.

Construction projects starting after July 1st, 2021 must use the 2021 Alaska Construction General Permit (ACGP)

Permanent Stormwater Controls

In March 2015, the MOA began implementing a new requirement concerning Operation and Maintenance (O&M) Plans for Permanent Stormwater Controls.  For many years O&M Plans were required to be submitted with building permit applications for all permanent structures that are designed to control site stormwater runoff water quality or quantity. Under the new requirement, these O&M Plans, together with an O&M Agreement, need to be recorded against the property title prior to the issuance of a Certificate of Occupancy.

This change was mandated by the Municipality of Anchorage’s Alaska Pollution Discharge Elimination System (APDES) stormwater permit from the Alaska Department of Conservation.  The intent of this change, as outlined in the APDES permit, is to ensure that O&M Agreements are legally enforceable and transferable with the responsible party and to assign a permanent responsibility for maintenance of structural or treatment control stormwater management practices.     

This change does not require any scope or format changes to the O&M Plans currently submitted to the Municipality of Anchorage for review.  There is however the additional O&M Agreement Form that will have to be recorded against the title of the subject property along with the O&M Plan. A copy of the O&M Agreement document is available here.

Questions regarding this new requirement may be forwarded to Watershed Management Services, at 907-343-8135.

Storm Water Treatment Plan (SWTP)

Developers of new and redeveloped sites are required to prepare and submit a Storm Water Treatment Plan.  The 2010 Storm Water Plan Review and Treatment Guidance Manual has been replaced with Volume 2 of the Anchorage Stormwater Manual. This maual provides guidance to developers to prepare and submit their SWTP. A handout on the SWTP outlines the review procedures available.

Storm Water Pollution Prevention Plan (SWPPP)

As part of the SWTP, contractors must develop and follow a Storm Water Pollution Prevention Plan (SWPPP) to manage materials, equipment, and runoff from a construction site. Watershed Management reviews SWPPPs for construction projects conducting ground disturbance greater than 500 square feet, including utility work, any work requiring a building permit, new subdivisions, and road projects. If you are a contractor, and would like more information on SWPPPs, visit the ADEC’s Storm Water Program website to download templates, permit documents, checklists, and FAQs.

Flood Hazard Permits

To minimize damage to structures during flood events and to enable residents to qualify for flood insurance, the Municipality of Anchorage requires a Flood Hazard Permit for all new construction in a floodplain.


Inspections of private and commercial projects are instigated from public complaints or other reports of non-compliance of regulations. During inspections, the SWPPP or other site documentation is reviewed, and a physical inspection of the site is conducted. Where corrections are needed, a re-inspection is scheduled to confirm compliance. When compliance isn’t achieved within the specified period of time, a stop work order is issued until compliance is achieved.

The Municipality must report to ADEC when they find projects which fail to comply with the Alaska Construction General Permit prior to breaking ground.