The Municipality’s
National Pollutant Discharge Elimination System (NPDES) storm water permit is a
five-year term permit to discharge storm water to U.S. receiving waters issued
jointly to the Municipality of Anchorage (MOA) and the Alaska Department of
Transportation and Public Facilities (DOT) by the U.S. Region X Environmental
Protection Agency (EPA). The MOA and DOT are operating under an extension of the
1st term permit issued in 1997.
Existing Permit Conditions (PDF: 82k - 42 pages)
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Under AMC 21.67 the Municipality of Anchorage requires the submission of site-specific plans for projects which may discharge storm water onto land, surface water or ground water within the Municipality. Any person who constructs, alters, installs, modifies, or operates a storm water treatment or disposal system must comply with plan requirements and reviews as specified in guidance documents established by the Director of Project
Management and Engineering. Land developers may be required to meet EPA and ADEC storm water plan requirements as well.
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EPA Storm Water Pollution Prevention Plans (SWPPP)
Under the EPA’s Construction General Permit (CGP), all land developers who plan to disturb 1 or more acres of land surface within the Municipality of Anchorage must submit a Notice of Intent (NOI) to EPA and prepare a Storm Water Pollution Prevention Plan (SWPPP). Private land developers must submit the SWPPP to the WMS (in their MOA building permit packet as part of the developer’s Municipal Storm Water Site Plan). Where the land development is publicly funded, developers submit the SWPPP to the Alaska Department of Environmental Conservation (ADEC). In the latter case, the land developer must obtain and include a copy of the ADEC’s Letter of Non-Objection in their MOA building permit packet. See links in Related Resources, right, for more information.
Municipal Storm Water Treatment Plans
Chapter 21.67 of the Anchorage Municipal Code requires anyone who undertakes land development to comply with storm water treatment planning requirements as specified in the Municipality’s Stormwater Treatment Plan Review Guidance Manual, specifically through submittal of a Storm Water Treatment Plan. The storm water plan typically includes submittal forms (MOA Handout AG-21), plan sheets showing pre- and post-development site topography and drainage, and proposals for construction storm water controls (SWPPP Plan elements) and permanent storm water controls (Storm Water Quality Control Plan elements including runoff calculations and soils and ground water information).
See links in Related Resources, right, for more information.
Storm Water Pollution Prevention Plans - Describes the type and location of storm water controls and a storm water maintenance and management plan that a developer intends to apply during the construction phase of a project. The MOA requires that an MOA-approved SWPPP be in place before construction begins. MOA’s requirements for an SWPPP are very similar to those required by the
EPA and are detailed in the Storm Water Treatment Plan Review Guidance Manual. See links in Related Resources, right, for more information.
Storm Water Quality Control Plans - Details the type and location of permanent storm water treatment devices that developer intends to install. MOA’s requirements for a permanent storm water treatment plan are detailed in the Storm
Water Treatment Plan Review Guidance Manual. See links in Related Resources, right, for more information.
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Watershed Management Services (WMS) is tasked
with the reconnaissance and mapping of streams on properties prior to development.
Land that is being subdivided, undergoing a Conditional Use Approval, a Site Plan
Review or lots one acre or greater seeking a permit through Development Services
Department, will require a review and may require stream mapping by WMS. The goal
of this program is to assist with land development and protect our local streams.
There are two Policies and Procedures (P&P) that affect this program. The first
is the
Municipal P&P that lays out the
requirements and the second is the
WMS P&P which explains how the program
will be implemented.
If your property development may require stream mapping or if you have general question
about streams please contact WMS. The points of contact for stream mapping are Steven
Ellis, 343-8078 and Scott Wheaton, 343-8117.
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| Based on AMC 21.60 WMS administers a Municipal floodplain management program to qualify the community for discounted flood insurance sponsored by the Federal Emergency Management Agency (FEMA). Anchorage’s floodplain management program consists of two basic elements: flood hazard mapping and regulation of floodplain development. |
Flood Hazard Mapping
Under FEMA standards and oversight, WMS administers and supervises mapping, updating and maintenance of all flood hazard maps within the Municipality. These maps delineate floodplain boundaries and flood hazard zones for different flood events and are used to identify where building and development activities must be regulated for community flood insurance purposes. Flood hazard mapping is typically printed on hardcopy Flood Insurance Rate Maps, or ‘FIRM’s, published directly by FEMA. Copies of these maps can be ordered directly from FEMA or obtained from the Municipality. Users should be aware that though the Municipality continuously updates flood hazard maps, FIRMs are only periodically re-published so that map updates are not always shown on the published maps. Review of recent map updates may be requested through the WMS Floodplain Administrator.
Hardcopy FIRMs can be picked up from the Municipal Floodplain Administrator at the Plans Counter in the MOA Permit Center in Anchorage. WMS also offers not-to-scale electronic scans of FIRMs covering the Municipality. Currently these digital copies can be downloaded from this site. These scans should not be considered as official copies of the original FIRMs and should only be used as planning tools. DFIRMs (official Digital Flood Insurance Rate Maps) are currently under preparation by the Municipality and are scheduled for publication on this website by mid-winter 2005/6, see Projects. See links in Related Resources right, for more information. |
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Floodplain Regulation
In order to maintain a community discount under the national flood insurance program, the MOA must enforce standard FEMA constraints on building and development within floodplain areas. Basic Municipal requirements are outlined in Handout No. 49: Flood Hazard Permit Requirments. See links in Related Resources, right for more information.
To administer the flood program, WMS reviews all land development plans as part of the MOA building permit review process to identify the location of the proposed development and facilities relative to flood hazard zones and the local ‘base flood elevation’ (BFE). If WMS finds the proposed development to be regulated under FEMA, the developer must comply with FEMA building constraints or appeal the finding through the procedure outlined in AMC 21.60.100.
A developer or homeowner may apply to amend or reverse the FIRM by submitting an application for a Letter of Map Amendment (LOMA) or a Letter of Map Revision (LOMR). For a LOMA to be approved, the developer must provide proof that the property does not in fact lie within the hazard zone(s) or that the proposed facilities are above local BFE. For a LOMR to be approved, the developer must submit new detailed flood hazard mapping that demonstrates the proposed development, though encroaching the mapped floodplain area, would not change the BFE. In any event, the Building Safety Division will not issue building permits for land developments within mapped flood hazard zones until all FEMA regulations have been met or mitigated. Typically banks will also not conclude loans until compliance with FEMA rules can be shown. |