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.
Infrastructure totals (including City, State, and private assets) in 2022 for the City of Kalispell:
1,724 manholes
4,417 inlets
132 stormwater basins
80 outfalls
123 miles of underground pipe (laterals and mains)
Small Municipal Separate Storm Sewer System (MS4) Permit
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.
Annual Report
View the annual reports for Montana DEQ’s stormwater permit for Kalispell.