Storm Water System

The storm-water system is regulated under a Phase 2, MS-4 MPDES permit issued by Montana DEQ. The City has developed a Storm-Water Management Plan and a Storm-water Master Plan.  New additions of infrastructure to the system and new connections that will discharge to the MS4 system must be developed to meet state standards, City of Helena Engineering standards and the system is operated to apply "Best Management Practices" to protect storm-water quality.

The storm-water system consists of:

  • 71 miles of storm pipe, which range from 8” to 90” pipes
  • 32.6 miles of open storm drainage ditch
  • 707 manholes
  • 1,790 storm inlets

This section will be responsible for helping to implement the Phase II storm water program.

Helena is divided into 6 drainage basins:

  • West Side
  • Last Chance
  • Davis
  • Bull Run
  • Airport
  • East Side

The crew cleans all 1,570 storm inlets yearly and performs hydraulic cleaning (jetting) of the pipes. Some 56,700 feet is annually inspected with a television camera to determine and inventory pipe conditions. You can find the Storm-Water Ordinance under the City Code 6-6-1

To report illicit discharges and other stormwater issues, please contact:

Matt Culpo - Stormwater Engineer
(406) 447-8073

BioHaven Floating Islands

These 4 BioHaven Floating Islands were installed at K-mart Storm Ponds in May 2014.  Our main goal for constructing these wetlands is to cleanse the water pollutants.  These islands have the unique ability to enhance the health of the stormwater ponds both environmentally and biologically.  These unique islands act as living bio-filters the plant roots and microbes consume excess nutrient sources that cause algae to bloom. 

We planted these islands like a wetland or garden with a variety of wet land plants that were recommended for our region.  These BioHavens provide many benefits including habitat restoration carbon sequestration and of course water cleansing.  It provides nesting and protection of specific species, and provides refuge for wildlife.  The BioHaven Floating Island matrix is constructed using 100% recycled pet plastic which means certified non-toxic; it’s from recycled drinking bottles.  After the plastic undergoes the recycling and spinning process, it is then turned into a MATRIX of fibers composed of layers of a durable synthetic mesh.  The matrix design resembles a pot-scrub or loofah which is important as it serves as a water filtration design.

floating island with plants
floating islands in permanent location