Last Updated 08/25/2026
Excerpt from Billings Stormwater Prevention for Commercial and Industrial Construction
Stormwater pollution occurs when water (including rain, snow melt, irrigation runoff) flows across surfaces and picks up pollutants, such as debris, chemicals, dirt, oil, and other pollutants, and discharges into surface and ground waters. The City’s stormwater collection system is designed to prevent flooding and not designed to remove pollutants created from residential, commercial and industrial uses. Construction activities, such as grading, excavation, and stock piling on commercial and industrial sites can increase stormwater runoff causing erosion and sedimentation from the site onto adjoining properties and city rights-of-way. Sedimentation may cause silting of storm drains, streams, ditches, and the Yellowstone River. contractors and builders must incorporate Best Management Practices (BMPs) to control both erosion and sedimentation from construction sites. National Pollutant Discharge Elimination System (NPDES) Billings participates in a mandated program under the Environmental Protection Agency (EPA) Clean Water Act. This program is designed to reduce the discharge of pollutants to the maximum extent practicable in order to protect water quality in state waters. The City of Billings is a permitted Small Municipal Separate Storm Sewer System (MS4) under the State of Montana NPDES program. In order to discharge stormwater into the city system, even during construction, a stormwater discharge permit is required. This permit is available on the City’s website.
Excerpts from Billings Stormwater Ordinance
Sec. 28-602 Maintenance of Stormwater Facilities
(a) Stormwater facilities shall be maintained by the owner or other responsible party in a condition so that the facilities will function as designed.
(b) Waste shall be disposed of from maintenance of facilities in accordance with applicable federal, state and local laws and regulations.
(c) The owner or other responsible party shall create and maintain records of installation and maintenance and repair for a period of five (5) years and shall be made available to the city public works department upon request.
(d) Any failure to maintain facilities or to correct deficiencies at facilities within a reasonable time after receiving written notice from the city may result in criminal or civil penalties. The city may perform corrective or maintenance work the owner or responsible person fails or refuses to perform within a reasonable time at the owner’s expense
Sec. 28-701. – Inspection
(a) The owner or other responsible party shall conduct annual inspections of the facilities and shall maintain records of such inspections for a period of five (5) years.
(b) Whenever necessary to make an inspection to enforce any of the provisions of this chapter, or whenever an authorized enforcement agent has reasonable cause to believe that there exists any condition which may constitute a violation of the provisions of this chapter in any building or upon any premises, the authorized enforcement agent may enter such building or premises at all reasonable times to inspect the same or perform any duty imposed upon the authorized enforcement agent by this chapter; provided that:
(1) If such building or premises is occupied, he or she first shall present proper credentials and request entry; and
(2) If such building or premises is unoccupied, he or she first shall make a reasonable effort to locate the owner or other persons having charge or control of the building or premises and request entry.
(c) If permission is refused or denied, or if it is not possible to locate the owner or responsible person and no emergency exists, the authorized enforcement agent shall obtain a warrant before entering the premises. If an emergency exists presenting imminent danger of serious injury to persons or property, the authorized enforcement agent may immediately enter into any building or upon any premises within the jurisdiction of the city for purposes of inspection or abatement.
(d) The city may conduct routine inspections as deemed necessary to carry out the objectives of this chapter, including but not limited to, random sampling and/or sampling in areas with evidence of stormwater pollution, illicit discharges, or similar factors.
(e) Unreasonable delays in allowing the city access to a permitted facility is a violation of a stormwater discharge permit and of this chapter.
View State Page
Resources
City of Billings – Stormwater Utility Development
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Billings Stormwater Pollution Prevention for Commercial and Industrial Construction
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City of Billings – Stormwater Homepage
View Resource
Billings Stormwater Ordinance
View Resource
Montana Department of Transportation Stormwater Management Plan
View Resource
Frequently Asked Questions
Why does construction on commercial and industrial sites matter for stormwater in Billings?
The city’s stormwater collection system is designed to prevent flooding, not to remove pollutants from residential, commercial, and industrial activity. Construction work like grading, excavation, and stockpiling can increase runoff and cause erosion and sedimentation onto adjoining properties and city rights-of-way, which can silt storm drains, streams, ditches, and the Yellowstone River.
Does a Billings construction project need a stormwater discharge permit?
Yes. Even during construction, discharging stormwater into the city’s system requires a stormwater discharge permit, available through the city’s website. Billings operates as a permitted small MS4 under Montana’s NPDES program, and contractors and builders must incorporate best management practices to control erosion and sedimentation on commercial and industrial sites.
How often does a Billings property owner need to inspect their stormwater facilities?
At least annually. The owner or other responsible party must conduct annual inspections and keep records of those inspections for five years, the same retention period required for installation, maintenance, and repair records.
Can the City of Billings inspect a stormwater facility without the owner's permission?
Generally no, except in emergencies. An enforcement agent must present credentials and request entry if the property is occupied, or make a reasonable effort to locate the responsible party if it’s unoccupied. If entry is refused or the owner can’t be located, the city must obtain a warrant unless an emergency presents imminent danger to people or property, in which case immediate entry is allowed.
What counts as a violation related to stormwater inspections in Billings?
Unreasonable delays in allowing the city access to a permitted facility are themselves a violation of both the stormwater discharge permit and the ordinance. The city can also conduct routine inspections, including random sampling or sampling in areas showing signs of stormwater pollution or illicit discharges.
What happens if a Billings property owner doesn't maintain their stormwater facilities?
Failing to maintain facilities or correct deficiencies within a reasonable time after written notice can result in criminal or civil penalties. The city can also perform the necessary corrective or maintenance work itself if the owner fails or refuses to do so, and bill the cost back to the owner.
The information on this page is provided for general informational purposes only and is not legal advice. Regulations change frequently — AQUALIS makes no warranty as to the accuracy or completeness of this content, and any reliance on it is at your own risk. Consult a qualified professional or your local regulatory authority to confirm requirements applicable to your specific property.
