Broadwater County to craft application process for DEQ sign‑off on accessory dwelling units in subdivisions

Broadwater County commissioners, planning staff and members of the public spent a meeting focused on how the county should respond when the Montana Department of Environmental Quality (DEQ) requests planning approval for accessory dwelling units within subdivisions, concluding that county staff should draft a formal ADU application and review process for commissioners to consider.

Nicole Brown, Broadwater County community development director and planner, told the commission she currently bases any DEQ-related planning approval solely on the original subdivision application and cannot approve an ADU where that application states “1 single family residence per lot.” Brown said she will draft a proposed ADU application process and research how other counties handle similar requests.

The issue matters because DEQ’s sanitation rules require an applicant to submit planning approval and supporting findings when a proposed change triggers the planning act; if an ADU is an independent living unit (with kitchen, laundry, sleeping and sanitation), DEQ generally requires a rewrite of the subdivision’s COSA (certificate of subdivision approval). That rewrite can change the sanitation approval…