Matanuska-Susitna Borough


Water that does not immediately soak into the ground from rain or snow melt is called stormwater. Stormwater can pick up sediment and pollutants as it runs across the ground and paved surfaces and carry these into streams, lakes and waterways. To protect our water resources from stormwater impacts, stormwater management tools and practices are needed, particularly for rapidly growing communities like the Mat-Su. Clean drinking water, plentiful fish stocks, the preservation of scenic and natural qualities, and ecosystem functions such as flood control are all important community objectives that can be enhanced by stormwater management. Using an EPA grant, the Mat-Su Borough developed a Stormwater Management Plan in 2013 in partnership with state and local governments.

Clean water is everybody’s business

When it Rains, it Drains

Rain and melting snow flow across surfaces like lawns and pavement, picking up silt, oil, chemicals, and debris. Sooner or later all this can flow into rivers, lakes, and even groundwater and aquifers.

Urbanization and Stormwater

Today the Mat-Su region generally enjoys clean water. Yet with our strong population growth and increased urbanization, this generally acceptable condition could change. For example, both Lake Lucille and Cottonwood Creek are on Alaska’s list of “impaired water bodies,” citing urban run-off as the issue.

When Water Drains, it's not Just Water that Drains

Pollution from everyday activities, over time, accumulates in waterbodies. Maintaining our water quality requires that everyone help prevent pollution. The top stormwater concerns in Mat-Su include:

  • Asphalt & roofs prevent natural filtering
  • Silt, sediment & debris
  • Disruption of natural drainage patterns
  • Septic failure & fertilizer over-use
  • Everyday cleaners, oil, & chemicals

What you can do?

Everyday actions make a difference, Do your part:

  • Appreciate clean water: drink from the tap; go fishing; hunt; view and photograph wildlife; and enjoy our scenic lakes, streams, and creeks.
  • Check out all the tips on this website so you know how to help keep our watersheds healthy.
  • Support waterway clean-up efforts.

Help implement the Mat-Su Borough Stormwater Management Plan.

Municipal Stormwater

When communities reach a certain population and density threshold, municipal governments are required to address stormwater by law. Because of health, safety, and cost issues associated with water quality, as communities become more urbanized, their discharges fall under the Clean Water Act of 1972, as amended in 1987. Once a community meets a population threshold, an Municipal Separate Stormwater Sewer System (MS4) permit is required to outline how a community must work together to keep pollutants out of their stormwater and environment.

Although Wasilla and Palmer are not yet at these thresholds, the recent census data could push them over the edge, creating new state requirements.  However, both communities are proactively looking at creative ways to both address their stormwater and to reduce infrastructure lifecycle costs by using best practices and low impact development (LID) techniques.

Palmer: Matanuska River

The City of Palmer operates a system of gutters, ditches, and buried pipes which convey untreated stormwater into the Matanuska River. The network is not adequately sized and does not reach all areas, resulting in occasional localized flooding. As development continues, the frequency and impact of the local flooding can be anticipated to increase. The City of Palmer recently listed local Stormwater Management planning as a Capital Project Priority.

Car, Boat and ORV


Soap, scum, and oily water can drain from your paved driveway into our lakes, streams, and coastal waters. How do you avoid this mess? Easy. Wash your car on gravel or grass to help filter the water, or take it to a car wash where the water gets treated and recycled.

Leaking oil goes from the car to the street. It then washes from the street into ditches, storm drains, culverts and into our lakes, creeks, and coastal waters. Now imagine the number of cars in the area and you can imagine the amount of oil that finds its way from leaks into our water. So please, fix oil leaks.


An oil sheen on the water is bad news. A little spilled fuel can go a long way and harm salmon and other aquatic life. Make sure fuel goes only into your tank—not into the water. Don’t leave a sheen. Prevent drips, spills and overfills.

Off Road Vehicles

Riding is fun. Riding in mud is ultra fun. But when mud is stirred up in streams, it hurts fish gills, eggs, and larvae. So avoid riding where fish are swimming and spawning. The fish—and everyone who likes to catch them—will thank you.


Heavy Equipment

Leaky gaskets. Hydraulic fluid drips. Fueling spills.  Don’t shortchange our water quality just because the construction season is short. Take the time to do regular maintenance, fuel a safe distance from waterbodies, and use oil absorbent pads to catch leaks. Your kids and grand kids will thank you.


You construct a new road or development. Sediment from earth work can be carried off-site by rain into creeks and lakes, which makes it hard for salmon to breathe and eggs to hatch. When you do construction, prevent erosion; leave natural vegetation buffers along streams, and trap sediment on-site. The salmon will thank you.

Subdivision Design

Subdivisions change natural drainage patterns. Plan adequate capacity to address rainfall and snowmelt on-site: “slow it down, spread it out, and soak it in.” Poor drainage can lead to flooding, unexpected costs, non-acceptance of private roads by the Borough, and poor curb appeal. Remember, when it rains, it drains.

Additional Resources for Developers

Alaska Construction General Permit:

  • Stormwater permits are required for projects draining into U.S. waters, and/or, with a disturbance area of greater than one acre

Engineering Plan Review: (Letter of Non-Objection)

  • Engineering Plan Review: According to 18 AAC 72.600, engineering plans should be submitted to DEC for review and approval. To obtain a "letter of non-objection" an applicant must submit a copy the Permanent Storm Water Management Control Plan Review Checklist with all documents listed on the General Project Information page. See the Frequently Asked Questions for answers to the commonly asked questions.

Additional Resources:

Home Owners


A failed septic system is bad news for more than your pocketbook.  Runoff can carry untreated sewage into our lakes and waters. Regular upkeep can keep your system working as it should. Your home septic system. Check it, fix it, maintain it.


You fertilize the lawn. Then it rains. The rain washes the fertilizer into our lakes, streams, and into coastal waters. This helps weeds and algae to grow, which uses up oxygen that fish need to survive.  If you fertilize, please follow directions and use sparingly. Or even better, keep lawns back from the shoreline, and retain a native vegetation buffer.


Dumping appliances, autos, and garbage isn’t cool. Next time you visit a lake, or drink tap water remember:  what ends up on the ground ends up in our water.

Additional Resources for Home Owners

Other Resources for Alaskan Homeowners

To Learn how to Properly Dispose of Appliances and other Household Items

Business and Industry

only rainKeep dirt and grime from washing into storm drains.

When it rains, runoff from your roof and parking area can pick up harmful chemicals; from dirt swept from work areas or materials leaking from a dumpster. Almost none of the runoff is treated before it flows into our streams, rivers, lakes, and Cook Inlet.

Help ensure that only rain goes down the drain.  Follow these best business practices to keep your business and our waters healthy:

  • Find your storm drains and mark them.
  • Keep waste and debris out of storm drains on your property.
  • Prevent contaminated wash water from going into storm drains.
  • Keep waste and debris out of the street drain, too.


  • Keep hazardous materials in closed, sturdy containers with labels.
  • Place containers indoors or under cover.
  • Keep dumpster lids closed.


  • Promptly repair all leaking connections, pipes, hoses, and valves.
  • Have your oil/water separator or catch basin cleaned regularly by a professional.


  • Put drip pans where spills/leaks are most likely.
  • Clearly label every container.
  • Have a spill kit on site and train your workers how to use it.
  • Use the least toxic material to get the job done.


Additional Resources for Business and Industry

Resources for Spill Prevention

Responding to a spill

Industrial Sectors where discharges of Stormwater are Regulated


You can help improve our watersheds

Across the Valley youth groups/schools, organizations, and individuals are helping to improve water quality.

Work efforts include:

  • Annual clean up days
  • Erosion control projects
  • Bank restoration
  • Water and fish monitoring
  • Education and outreach
  • Natural buffers and filters