The Erosion Control and Stormwater Management Ordinance was designed to help protect Dane County’s lakes, streams, wetlands and quality of life by reducing the negative impacts of sediment, rainfall, melting snow and other water runoff.

The ordinance establishes countywide standards for the quantity and quality of water that runs off land under construction in urban and rural areas, including farms. It also provides flexibility in meeting those standards, recognizing the unique characteristics of each project and site. The Erosion Control and Stormwater Management Ordinance builds on the construction site erosion control requirements that have been in effect since 1995.

The Dane County Board of Supervisors adopted the Erosion Control and Stormwater Management Ordinance effective August 22, 2002, acting on the recommendation of the Dane County Lakes and Watershed Commission after 11 public hearings and hundreds of hours of meetings with citizens, technical experts, developers, builders, local municipalities, and other stakeholders. The Board found that construction site erosion and uncontrolled stormwater runoff from land disturbing and land development activities have significant adverse effects upon regional water resources including the health, safety, property and general welfare of the community, diminishing the public enjoyment and use of natural resources. The Board also found that effective erosion control, sediment and stormwater management depends on proper planning, design, timely installation and continued maintenance of erosion control and stormwater management practices. Specifically, they found that soil erosion and stormwater runoff can:

• carry sediment, nutrients, pathogens, organic matter, heavy metals, toxins and other pollutants to regional lakes, streams and wetlands;
• diminish the capacity of water resources to support recreational and water supply uses and a natural diversity of plant and animal life;
• clog existing drainage systems, increasing maintenance problems and costs;
• cause bank and channel erosion;
• increase downstream flooding;
• reduce groundwater recharge, which may diminish stream base flows and lower water levels in regional lakes, ponds and wetlands;
• contaminate drinking water supplies;
• increase risk of property damage and personal injury
• cause damage to agricultural fields and crops

Effective January of 2006, revisions to the erosion control and stormwater management ordinance were made to meet state standards for infiltration and to make shoreland erosion control requirements of Chapter 11 consistent with Chapter 14. Dane County chose to adopt the state’s infiltration standards, with few modifications. One significant change was a sunset date for the caps that limited that amount of area required to be dedicated to infiltration (State rules require only one percent of a residential site and two percent of a nonresidential site to be dedicated to infiltration). The other significant change was the elimination of the design storm approach (utilizing TR-55) to meet the infiltration requirements. The Dane County Lakes and Watershed Commission also assembled an infiltration taskforce to explore regulatory alternatives to caps and evaluate stormwater infiltration in Dane County. The taskforce included members from the academic, development, municipal, regulatory communities, and watershed groups. After nearly a year of work, the taskforce returned to the Dane County Lakes and Watershed Commission with a full report including a unanimous recommendation to remove the caps and include an alternative recharge performance standard. The revised infiltration requirements were adopted in August of 2006, and are now effective.

For information on permit applicability, fees and review process, please see the Permit Information page.

A preliminary review letter provides a potential permit applicant with an initial evaluation of whether erosion and stormwater control standards can be met for a proposed site, lot layout, or construction design. A preliminary review is required to qualify for certain shoreland erosion control plan requirement exceptions. This general review is intended to assist applicants in preparing general site plans and other submittals necessary to obtain an erosion control and/or stormwater permit. A preliminary review letter does not guarantee that an erosion or stormwater control plan will be approved or that a permit will be issued.

Although cities and villages are not required to include a preliminary review process in their ordinances, Dane County strongly encourages use of this practice. The early consultation before lot line, road and infrastructure decisions have been made is especially helpful for first-time or one-time developers.

The ordinance sets countywide standards and gives the necessary flexibility to local governments and developers so they can administer and meet those standards effectively and efficiently.

• The ordinance is administered by the Dane County Land and Water Resources Department, Water Resource Engineering Division, in unincorporated areas (towns).
• Cities and villages (incorporated areas) administer the ordinance if they have adopted stormwater and erosion control standards at least as restrictive as the county ordinance.

The various models currently accepted for use in calculating hydrology, infiltration, soil erosion rates, water quality impacts and temperature impacts include P8, RECARGA, TR-55, WinSLAMM, USLE (RUSLE2, when available), TURM, and Stokes Law.

Water Resource Engineering Division staff review new analytical tools for use with the Erosion Control and Stormwater Management Ordinance. The user community is encouraged to submit models for consideration. The LWRD Director, per Section 14.53(3) of Dane County Code of Ordinances, may approve new models. Description of the model, relevant mathematical analysis, relevant supporting documentation, simplicity of model, consistency of parameter estimates and sensitivity of results to changes in parameter values will all be considered when evaluating new models.

The ordinance allows local authorities to establish their own fee schedules for erosion control and stormwater management permits within incorporated areas. In unincorporated areas, fees are set by Dane County.

Dane County will work with municipalities for consistent enforcement of the county minimum standards.

*The ordinance requires builders, developers and other site planners to submit erosion control and stormwater management plans. If a site is not in compliance with its plan as determined by inspection, a stop-work order may be issued and the administrator may levy fines. *If a city or village does not adopt standards at least as restrictive as the county ordinance or has adopted county standards but the Lakes and Watershed Commission finds that they are not effectively administering and enforcing them, the Dane County Land and Water Resources Department will administer the provisions of the ordinance in that municipality.

NR 151 "Runoff Management" includes construction site and post-construction runoff pollution performance standards. Sites may be subject to both Dane County Ordinance and NR 151 Runoff Management Rule.

• Dane County Chapter 11 - Shoreland, Shoreland-Wetland And Inland-Wetland Regulations
• Dane County Chapter 14 - Erosion Control And Stormwater Management