Commission weighs new rules that would require homeowners to retain first inch of runoff; residents raise cost and feasibility concerns

Birmingham planners on Tuesday introduced a proposed ordinance to require single‑family properties to retain the first inch of rainfall on impervious surfaces, a step the city says is needed to meet goals in its 2024 Birmingham Green Healthy Climate Plan.

Summer Aldren, the city planner leading the proposal, told the commission the rule would aim to “retain or infiltrate an additional 500,000 gallons per rain event” across the city and would apply differently to full tear‑downs, new builds and smaller additions or replacements. She said small projects under 500 square feet would be limited to natural measures; larger work would be a mix of natural measures (plants, rain gardens) and constructed systems such as dry wells or trenches.

The proposal immediately drew sustained public comment and lengthy questioning from commissioners. Commissioner Kozlowski said he wanted concrete, illustrated examples for small, medium and large lots and warned the policy could impose high costs or require homeowners to install underground retention systems. “If I put in a new driveway, what am I required to do?” he asked. Aldren and engineering staff responded that common, lower‑cost options—adding trees, a rain garden, or modest subsurface detention—would often meet the requirement and that the administration planned flexible review and a “mix‑and‑match” worksheet for applicants.

Resident speakers described recurring basement sewage, standing water that attracts mosquitoes, and streets with aging sewer lines. Erica Driscoll, who said her husband was killed in a recent crash while walking in a neighboring community, pressed commissioners for safer street design rather than focusing only on private‑lot measures.

Commission discussion focused on three recurring concerns: (1) whether driveway replacements or other like‑for‑like work would be forced into costly mitigation, (2) whether owners of modest lots would be able to fit required measures without losing usable yard, and (3) whether the city should prioritize engineering solutions—larger mains or targeted infrastructure projects—instead of, or alongside, requiring private retention systems. Aldren said staff would prepare clearer examples and cost estimates and warn that the measure aims to slow runoff rather than permanently “store” water on private property.

The commission did not adopt the ordinance Tuesday. Several members asked staff to return with model plans, ballpark cost ranges, clear guidance for replacements versus new builds, and an outreach plan that would tell contractors and homeowners what to expect. Aldren said staff would also propose exemptions and implementation details for owner‑occupied properties and seek feedback from builders, architects and the public.

The commission’s vote on whether to place the ordinance on a future agenda is expected after the administration returns the requested clarifications. The staff presentation said companion technical guidance would reference Oakland County design criteria and that staff will pursue an implementation approach that balances environmental goals with development realities.