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310 Permit Information

Montana’s Natural Streambed and Land Preservation Act, also known as the 310 Law, is a state law that requires any person planning to work in or near a stream or river on private or public land to first obtain a 310 Permit from their local conservation district.

Permits are free of charge.

The purpose of the 310 Law is to ensure that projects on streams are carried out in ways that are not damaging to the stream or to adjoining landowners.

Conservation districts throughout Montana administer the 310 Law.  Missoula Conservation District administers the 310 Law within Missoula County, outside of the 1946 Missoula City limits. For projects within the 1946 city limits, contact Missoula County. On tribal land, contact the Confederated Salish and Kootenai Tribal Shoreline Protection.

The permitting process takes between 30 and 90 days. Once approved, a 310 permit is valid for one year. Permits decisions are made by the Missoula Conservation District Board of Supervisors during the monthly meetings, which occur on the second Monday of each month. Meetings are open to the public.
Annual permits are also available for routine maintenance work, such as opening/clearing ditches, and valid for up to ten years.

1) Application Process
All information requested on the 310 application along with a plan and/or drawing of the proposed project and a site map must be provided. Incomplete applications may be rejected. Applications are reviewed and accepted at the monthly district meetings. After a 310 application is received, Montana Fish Wildlife and Parks is notified of the proposed project and may request an on-site inspection.

To ensure your application is submitted on time for review at the next district meeting, please see our Calendar.

2) Site Inspection Process
A team, consisting of the district resource conservationist, district supervisor, a Montana Fish, Wildlife, and Parks representative, and the applicant or applicant’s representative will meet to discuss the project on site. The applicant or their representative is entitled to be a team member for the purposes of making recommendations to the district. Team members may waive participation in the on-site inspection.

After an inspection is conducted, team members make recommendations to the district at a regular meeting. The applicant can waive participation, submit a team member report jointly with other team members (if in agreement with their recommendations), or submit a separate report.

If no inspection is required, the district may proceed with the application and the applicant will be notified of the supervisors’ decision.

3) Decision Process
The district will decide whether to approve, modify, or deny the project within 60 days of acceptance of the application. However, this time period can be extended if the district determines it necessary to collect further information. After receiving the supervisors’ decision, the applicant has 30 days to return the permit, signed to indicate agreement with the district’s decision. Unless otherwise stated on the supervisors’ decision form, the applicant must wait 30 days before proceeding with the project.

Considerations that must be addressed by the district in making their decision:

  • The effects on soil erosion and sedimentation, considering the methods available to complete the project and the nature and economics of the various alternatives
  • The effects of stream channel alteration
  • The effects on streamflow, turbidity, and water quality caused by materials used or by removal of ground cover
  • The effects on fish and aquatic habitat
  • Whether there are modifications or alternative solutions that are reasonably practical that would reduce the disturbance to the stream and its environment and better accomplish the purpose of the project
  • Whether the proposed project will create harmful flooding or erosion problems upstream or downstream
There is no fee for a 310 Permit. Applications can be picked up in the district office or downloaded on our website. Please check the calendar for application deadlines and note that an original signature from both the applicant and the landowner is required with each application. For questions, contact Missoula Conservation District by calling (406) 258-3430, writing, or stopping in the office at 1075 South Ave. West, Missoula, MT 59801.
There is an emergency provision in the 310 law to handle actions necessary to safeguard life or property, including growing crops, during periods of emergency. If a person takes an emergency action, the conservation district must be notified within 15 days in writing of the action taken and why. The emergency action will be reviewed by the conservation district. The district will decide whether the action was appropriate, must be modified, or must be removed and/or replaced.

It is a misdemeanor to initiate a project without a permit, to conduct activities outside the scope of the permit, to violate emergency procedures or to use prohibited materials in a project. Upon conviction of a misdemeanor, a person may be punished by a fine up to $500 or by a civil penalty not to exceed $500 per day for each day the person continues to alter the stream. In addition, the person may be required to restore the damaged stream to a condition as close to its prior condition as possible, as recommended by the District supervisors.


Examples of Projects Requiring a 310 Permit*:

  • Channel Changes/Dredging
  • New Irrigation Diversions
  • Streambank Protection Projects
  • Culvert Installation/Removal
  • Bridge Installation/Removal
  • Ford Crossings

*A permit may also be required if an existing project needs repair and/or alternations.

Examples of Prohibited Projects:

Unless specifically authorized by the board through a 310 permit, the following activities are prohibited

  • The placement of concrete in a stream as rock riprap
  • The placement of road fill material in a stream
  • The placement of debris or other material in a stream where it may erode or otherwise enter the stream
  • Projects that permanently prevent fish migration
  • Removal of streambank vegetation within the immediate banks of the stream, unless necessary for completion of the permitted project
  • Excavation of streambed gravels
  • Construction of an in-stream pond