Flood Zones in Matanuska-Susitna Borough
Matanuska-Susitna Borough has three major river systems that create flood zone exposure for a meaningful portion of its properties. The Matanuska River, the Knik River, and the Susitna River each carry Zone AE flood zone designations along portions of their corridors. Beyond the main river channels, properties in communities including Big Lake and Meadow Lakes may fall within flood zone boundaries depending on local drainage conditions. Some low-lying parcels near Palmer, including areas adjacent to the Palmer Hay Flats, also have flood zone considerations tied to the surrounding agricultural landscape.
When a property falls within a Special Flood Hazard Area (SFHA) and carries a federally backed mortgage, the lender is required to mandate flood insurance. The elevation certificate is the document that allows the National Flood Insurance Program to rate that policy accurately based on the specific elevation of the structure on the insured property.
The Three River Corridors
Matanuska River
The Matanuska River flows southwest through the borough and carries Zone AE designations along its lower reach as it approaches Knik Arm. Properties in the floodplain of the lower Matanuska corridor are among the most commonly cited for flood insurance requirements in the borough. Elevation certificates for these properties document the lowest floor elevation of the structure relative to the Base Flood Elevation shown on the applicable flood insurance rate map.
Knik River and GLOF Risk
The Knik River presents a situation not found along most rivers in the contiguous United States. Knik Glacier, located in the upper Knik drainage, has a documented history of glacial lake outburst floods (GLOFs). These events occur when water impounded behind or beneath the glacier releases rapidly, sending a surge downstream that can exceed normal flood levels by a significant margin. The lower Knik River valley carries Zone AE designations that reflect both standard riverine flooding and this GLOF risk.
For property owners in the lower Knik River valley, the combination of standard flood zone designation and GLOF exposure means flood insurance is a meaningful consideration. An elevation certificate documents the specific elevation of a structure and gives the insurance underwriter the information needed to rate the policy. A surveyor familiar with the flood insurance rate maps that apply to this corridor will be able to complete the certificate efficiently.
Susitna River
The Susitna River flows along the western edge of the borough and also has Zone AE sections. Properties near the Susitna that fall within the SFHA and carry a mortgage are subject to the same mandatory flood insurance requirements as properties along the Matanuska or Knik. Elevation certificates follow the same process regardless of which river system generates the flood zone designation.
Big Lake, Meadow Lakes, and Palmer Area Properties
Beyond the three main river corridors, some properties in the Big Lake and Meadow Lakes communities fall within flood zone boundaries depending on local drainage. Big Lake itself is a popular recreational area, and some waterfront or low-lying properties near the lake may have flood zone designations. Near Palmer, certain parcels adjacent to the Palmer Hay Flats or low agricultural areas may also have flood zone exposure.
A flood zone determination is the first step before ordering an elevation certificate. Your lender or title company can typically obtain a flood zone determination as part of the transaction process. If the property is in a Special Flood Hazard Area, an elevation certificate follows.
What an Elevation Certificate Documents
The elevation certificate is a standardized FEMA form completed by a licensed land surveyor who physically visits the property. It records:
- The elevation of the lowest floor of the building, including any attached garage
- The elevation of the lowest and highest adjacent grades at the building
- The flood zone and Base Flood Elevation shown on the current flood insurance rate map for that location
- Building type and construction characteristics
- The presence and elevation of any enclosure below the lowest floor
- Photographic documentation of the structure and grade conditions
The flood insurance underwriter uses this data to determine the appropriate premium. A structure with a lowest floor well above the Base Flood Elevation will receive a lower premium than one at or below it. For rural Mat-Su properties where the difference in annual premiums can be several hundred or even thousands of dollars, a $500 to $900 elevation certificate is a sound investment before purchasing or renewing a flood insurance policy.
The LOMA Option
A Letter of Map Amendment (LOMA) is a formal submission to FEMA requesting that a specific property or structure be removed from the Special Flood Hazard Area. If the elevation certificate shows the lowest floor above the Base Flood Elevation and the property meets other criteria, FEMA may approve the LOMA and make flood insurance optional for that parcel even if the surrounding area remains mapped in Zone AE. A licensed surveyor can evaluate the elevation data and advise on whether a LOMA application is worth pursuing.
Cost in Matanuska-Susitna Borough
Standard residential elevation certificates in Mat-Su cost $500 to $900. Properties with difficult access via unmaintained or seasonal roads may carry additional mobilization cost. The surveyor must visit the property in person to collect the measurements required by the FEMA form, so remote locations in the borough fringe will generally cost more than properties in Wasilla or Palmer with paved road access.
Finding a Surveyor for an Elevation Certificate
Elevation certificates must be signed by a licensed professional land surveyor in Alaska. The Mat-Su Borough surveyor directory lists the 10 licensed firms serving the borough. When reaching out for quotes, provide the property address, parcel number, and the name of the river corridor or community involved so the firm can give you an accurate estimate.