Regulatory FrameworkStormwater Management Plan For City of Bozeman 2022-2027

In recent years the City of Bozeman has been striving to improve waterway health, protect public safety, and comply with its MS4 Permit through the regulation and oversight of existing and new structural Best Management Practices (BMP) in the following ways:

1. Enforcement of water quality and flood control standards on new and redevelopment projects;

2. Inspections of structural BMP’s

Regulatory Framework-

Runoff generated from the first half inch of rainfall (first flush) contains the majority of pollutants deposited on impervious areas during dry periods. Structural BMP’s mitigate pollutants from entering waterways by capturing the first flush. Using BMP’s, the MS4 requires new and redevelopment projects over one acre to capture the first half inch of rainfall.

Developers must implement structural BMP’s, which can include surface detention and retention facilities, permeable pavers, and underground infiltration facilities. In Bozeman, structural BMP’s must also be designed to limit runoff to the predevelopment level during a 10 year, 2 hour storm. This reduces peak runoff and helps protect waterways, property and human health.