Home » Management Stormwater Management Butte-Silver Bow MS4 Annual Reports 2019 Annual Report 2017 Annual Report 2016 Annual Report 2015 Annual Report Management Program Documents Butte-Silver Bow MS4 Storm Water Management Plan (SWMP) Enforcement Response Plan (ERP) MS4 Stormwater Sampling and Analysis Plan (SAP) Program Updates 2017-2019 BSB Storm Water Sample Results