Environmental Rules in Montana (2026)
9 rules on the books across Montana, 2 cities and counties. Select a rule to read the full details.
Severity: Few Restrictions · Light Restrictions · Some Restrictions · Significant Restrictions · Heavy Restrictions
Stormwater Management
Requirements for managing rainwater runoff on your property, including retention basins, permeable surfaces, and drainage plans.
Montana: statewide
StatewideSome RestrictionsMontana requires a Montana Pollutant Discharge Elimination System permit before stormwater reaches state waters. Under…
Read full rule →Billings
Some RestrictionsBillings bills every premises in the city a monthly storm sewer system service charge to fund stormwater…
Read full rule →Erosion Control
Rules to prevent soil erosion during construction and landscaping, including required sediment barriers and ground cover standards.
Montana: statewide
StatewideSome RestrictionsMontana requires an MPDES construction stormwater permit before any land disturbance of one acre or more, enforced by…
Read full rule →Billings
Some RestrictionsConstruction disturbing 1+ acre, or within 50 feet of a watercourse, must file a Notice of Intent and Storm Water…
Read full rule →Yellowstone County
Some RestrictionsYellowstone County's zoning code requires sod or another erosion control product anywhere a landscaped lawn sits in a…
Read full rule →Flood Zones
Building requirements for properties in FEMA flood zones, including elevation standards, flood insurance mandates, and construction limits.
Montana: statewide
StatewideHeavy RestrictionsThe Montana Floodplain and Floodway Management Act (Title 76, Ch. 5, MCA) requires DNRC-approved local floodplain…
Read full rule →Billings
Some RestrictionsBillings requires a floodplain permit before any fill, structure, or artificial obstruction is placed in a mapped flood…
Read full rule →Boat Dock Permits
Permits required to build or modify boat docks, lifts, and davits on waterfront properties, including size limits, setbacks, and environmental reviews.
Flood Elevation Requirements
FEMA NFIP minimum base flood elevation (BFE) construction standards for properties in mapped flood zones, including freeboard requirements above BFE.