Stormwater Management Program

A Municipal Separate Storm Sewer System (MS4) consists of a city's stormwater conveyance system including underground pipes, roads with drainage systems, gutters, and ditches. 

storm drain solid lid

Infrastructure totals (including City, State, and private assets) in 2021 for the City of Kalispell:

  • 1,551 manholes
  • 4,182 inlets
  • 112 stormwater basins
  • 78 outfalls
  • 114 miles of underground pipe (laterals and mains)

Small Municipal Separate Storm Sewer System (MS4) Permit

The City of Kalispell is designated as a Small MS4 and is permitted under the Montana Department of Environmental Quality's MPDES General Permit for Storm Water Discharges Associated with Small Municipal Separate Storm Sewer Systems (MS4s). 

The Permit requires Kalispell to develop, document, and maintain a Stormwater Management Program (SWMP) (PDF) to reduce the discharge of pollutants from the Small MS4 to the maximum extent practicable. 

The goal of the program is to protect and improve local water quality because most stormwater enters local rivers and streams without any treatment.

Stormwater Management Program Cover
Stormwater Annual Report Cover

Annual Report

View the annual reports for Montana DEQ’s stormwater permit for Kalispell.

Suggestions or Comments

To provide suggestions or comments on the SWMP please fill out the SWMP Public Input Form.

Stormwater Sampling

The City samples stormwater to better understand what is in our stormwater and the effectiveness of best management practices. View our MS4 Sampling Plan for TMDL-Related Monitoring and our 2021 Stormwater Sample Evaluation. 

Multiple stormwater samples in glass containers
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