Planners review proposed stormwater ordinance; sanitary district, Purdue model cited as basis for update

The Michigan City Plan Commission on Feb. 25 reviewed a proposed consolidated stormwater ordinance and companion technical standards intended to replace stormwater provisions scattered through the city code, streamline permitting and meet state permit requirements.

Raul Wallace, the sanitary district’s stormwater coordinator, briefed the commission on the draft document and technical manual, which follow the Purdue Local Technical Assistance Program’s 2022 model ordinance and were prepared with input from IDEM, county surveyors and regional engineers. Wallace said the update is driven in part by the renewed Construction Stormwater General Permit and MS4 requirements; he told commissioners the Sanitary District approved the draft ordinance and technical standards on Jan. 23.

Wallace highlighted two primary goals: control stormwater quantity from new development to avoid increased runoff and protect conveyance systems, and control stormwater quality because discharges reach Trail Creek and ultimately Lake Michigan. He emphasized attention to frequent, small storms (1-to-2-year return intervals) that cause erosion of ditch banks and cumulative maintenance issues, not just rare large storms. Wallace also described a proposal to consolidate stormwater language from several chapters and appendices of the Michigan City code into a new Article 9 under Chapter 46 (Environment) so developers and reviewers can find requirements in one place.

City staff noted the draft includes a basin maintenance-agreement requirement to ensure long-term upkeep of basins often owned by private associations or developers. Commissioners and staff discussed common problems with aging basins — sedimentation, invasive vegetation such as phragmites, and debris — and noted modern survey tools (including drone-based topography and volumetric calculations) can help assess basin condition when redevelopment occurs.

Resident commenter Scott Melland praised the ordinance update and asked whether the model ordinance allows green infrastructure such as swales and rain gardens; Wallace and staff said the standards provide options for vegetated practices. Melland also asked about enforcement tools for nonfunctioning private basins; staff said basin maintenance agreements and clearer ordinance language will provide stronger authority than previously existed, and that retroactive requirements depend on the ordinances in place when a basin was built.

Wallace outlined the remaining timeline: planning commission consideration of formal approval in March, subsequent City Council review likely through three readings (with a workshop anticipated), and final ordinance codification followed by any necessary coordination back to the Sanitary District. No formal vote on the ordinance occurred at the Feb. 25 meeting; commissioners asked clarifying questions and generally expressed support for streamlining the code and improving maintenance requirements.