Madison, WI Environmental Rules: Stormwater Management (2026)

Sec. 09, Stormwater Management Plan Requirements, governs the plan itself once Sec. 06(3) has already required a stormwater management permit. Every applicant must submit a plan documenting the systems and measures proposed to control runoff, including a completed standard stormwater management summary template available from the City's Engineering Division, and the plan must be completed and sealed by a Professional Engineer licensed in Wisconsin. The Administrative Authority (the City Engineer's office) may additionally require a financial security instrument guaranteeing the stormwater systems actually get built.

Required plan contents include a narrative description of the project with an implementation schedule, identification of who is responsible for long-term maintenance, a topographic map of the site and contiguous properties showing existing drainage patterns and vegetative cover, a map of drainage areas by watershed, and a full set of peak-flow-rate calculations covering pre-existing conditions, post-construction conditions without detention, and post-construction conditions with detention, using specified runoff curve numbers tied to Hydrologic Soil Groups. The performance standards in Sec. 09(1)-(3) apply differently depending on the trigger: full development, redevelopment, site disturbance/grading of an acre or more, street reconstruction, and parking-lot resurfacing each pull in a different combination of the plan's total-suspended-solids, rate-control, and infiltration requirements.