Delafield council votes to begin ordinance amendment on impervious-surface limits for lakefront lots

The Delafield Common Council on May 19 voted to initiate an application to amend Chapter 52 of the city zoning ordinance to add limits on impervious surfaces for certain lakefront lots and referred the matter to the Plan Commission to prepare text and schedule a public hearing.

Council initiation follows a multi-year review by the Lake Welfare Committee and the Plan Commission. City staff and committee members said the recommended threshold is a 50% maximum impervious surface for affected lots; the change would apply to lots meeting criteria discussed by committees, including a 20,000-square-foot lot threshold and at least 100 feet of water frontage as part of the original Lake Welfare proposal. Current city code already prohibits impervious surfaces within 35 feet of the ordinary high-water mark, with exceptions for boathouses that comply with DNR rules and single walkways not exceeding five feet.

Council members and staff urged the Plan Commission and Lake Welfare Committee to develop specific language, enforcement procedures and administrative steps. Staff warned the council that the city does not currently track citywide impervious-area percentages and that establishing baseline data could require aerial analysis or other surveys. Staff also said reviews of treated impervious surfaces or permit applications could require engineering review and new application fees; the cost of that review would likely fall to applicants.

Speakers pressed several practical and equity questions: whether properties with existing excess impervious area would be grandfathered, how shared private roads or roadway easements would be counted, and what resources the city would need to enforce a new standard. Council members noted the proposal is intended to discourage wholesale replacement of yards with impervious material on large lots when homes are torn down and rebuilt, but not to prohibit small patios, walkways or modest improvements. Council members asked the Plan Commission to consider exemptions, measurement rules for easements and private roads, and how to treat existing nonconforming lots.

After extended discussion about administrative burden, fairness and environmental goals, a council member moved to “initiate text amendments to chapter 52 zoning ordinance regarding impervious surface provisions as recommended by Lake Welfare Committee, and the matter placed on the next Plan Commission agenda to schedule a public hearing.” The motion was seconded and approved; the council recorded at least one vote in opposition during the voice vote.

Next steps: Plan Commission and Lake Welfare Committee will prepare proposed language, estimate administrative costs, and present a draft ordinance for a public hearing before the council considers any final adoption. Staff advised that the city will need to decide who reviews permits, whether to require survey evidence or aerial analysis, and what application fees to charge if the amendments require engineering review.

Why it matters: The proposed amendment targets buildup of impervious surfaces that can increase stormwater runoff to Delafield’s lakes. Council members framed the change as a tool to address large rebuilds and new construction near the lakes rather than small homeowner improvements. The Plan Commission referral means the matter will return for more technical detail and a public hearing before any binding change is adopted.