Delafield planners pause push for strict impervious-surface limits; ask staff for targeted analysis

Delafield City Plan Commission members on May 28 discussed new limits on impervious surface near lakefront properties but did not send an ordinance to public hearing, instead asking staff and Lake Welfare Committee members for a more targeted analysis.

The commission reviewed a proposal from the Lake Welfare Committee that would have set a higher minimum standard for maximum impervious coverage on lake lots (the committee had discussed a 60 percent threshold in prior meetings). City planner Amy Barrows told the commission the draft language as written raised technical and enforcement questions and that the city should first define the policy goals, the parcels affected and how mitigation or treatment of runoff would be required and tracked.

Commissioners and staff said the policy should be tied to the problem it is intended to solve — protecting water quality and controlling runoff — rather than a single, across-the-board percentage. Members suggested mapping lot types (for example RL‑2 lakefront lots versus deeper inland lots), checking existing SEWRPC (Southeastern Wisconsin Regional Planning Commission) and Wisconsin Department of Natural Resources guidance, and estimating how many parcels would be covered by different thresholds before returning with a revised proposal. Council members had earlier expressed concern about staff workload, enforcement costs and whether small improvements (patios, small driveways) would be exempted or undermine the rule.

Barrows said technical options include requiring engineered mitigation (rain gardens, infiltration) for larger proposals or using different maximums for defined lakefront zones. Commissioners also discussed that SEWRPC and DNR guidance provide useful starting points but that Delafield’s regulations should match local lot patterns and enforcement capacity. No public hearing was scheduled and the commission asked staff to return with maps, impact estimates and draft ordinance language tailored to the lake’s variety of lot types.

The commission’s direction was procedural — staff was asked to refine the proposal so commissioners and the Common Council can evaluate tradeoffs, rather than to act immediately on a numeric cap.