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Great Falls Storm Drain Design Manual

STORM DRAIN POLICY UPDATES AND DRAIN DESIGN MANUAL

Great Falls, Montana

Project Description

The City of Great Falls needed to develop new stormwater policies and update their Storm Drain Design Manual (SDDM). The project involved three main segments: a new Regional Treatment Facility (RTF) funding policy and tracking tool; a new contractor erosion control training policy and program; and updates to the City’s design manual and local stormwater permits. The goal of the project is to help the City continue to improve storm utility operations and permit compliance.

Great Falls stormwater drain design manual

Meeting the Requirements

The City maintains and operates a stormwater utility that falls under the Municipal Separate Storm Sewer System (MS4) program and therefore must meet EPA and MT DEQ permit requirements. The City has implemented six Minimum Control Measures (MCMs) to maintain compliance with the MS4 permit:

      1. Public Education and Outreach
      2. Public Involvement and Participation
      3. Illicit Discharge Detection and Elimination
      4. Construction Site Stormwater Management
      5. Post-Construction Site Stormwater Management
      6. Pollution Prevent/Good Housekeeping for Operations

This project will further bolster MCM 4 and 5 and indirectly address requirements for public engagement (MCM 1 and 2).

The new RTF policy formalizes the rules and funding mechanism to support the development of stormwater treatment facilities that serve large areas. Because development within the drainage boundary of an RTF may occur at varying rates, the City needed a long-term solution to track cost-sharing. This policy will enable the City to continue acting as the primary responsible party for funding RTFs. In addition, it will define the responsibilities and costs that developers may be asked to contribute for use of the RTF in their development plan. The cost-sharing tool is easily integrated into the City’s Public Works and Accounting departments existing procedures.

The new Preferred Contractor Program (PCP) establishes a policy to incentivize contractors that frequently do work in the City to become locally certified in erosion and sediment control management. The City currently experiences common erosion and sediment control issues in construction sites that ultimately may lead to fines from the DEQ. The intention of the new program is to allow local contractors to engage with City staff and decrease the occurrence of construction site infractions. The program includes an individualized Stormwater Pollution Prevention Plan (SWPPP) training to be administered by the City that will meet the State’s certification criteria.

Updated Manual

The final segment of this project is an update to the City’s Storm Drain Design Manual to make it consistent with current policies and design criteria.  The project is ongoing and expected to be complete by the end of 2021.

Project Details

Date: 2021 – 2022

Client: City of Great Falls

Key Project Elements
  • Stormwater Improvements Planning
  • Facility Funding Policy
  • Public/Private Cost Share Tracking Tool
  • Design Manual Updates
  • Erosion Control Contractor Training Programs Policy and Curriculum Development
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