What is an ESA?
An ESA, or Environmentally Sensitive Area, is a landscape feature identified in a Sewer Service Area Plan due to its role in maintaining and protecting water quality. ESAs, which may include waterways, wetlands, sloping land, Karst features, floodways, and setback areas, are prohibited from development to ensure local water quality is maintained. ESAs and ESA setbacks are not buildable areas. Development and earth moving activities should not occur within ESAs or ESA buffers.
Can I change an ESA boundary on my property?
ESAs are identified, mapped, and published online to provide notice to communities, the public, and developers of areas prohibited from public sewer development. Properties purchased after the delineation of an ESA (displayed on the property’s plat map) should be maintained. Questions involving acceptable activities within and near an ESA can be directed to the Brown County SSA Plan Contact Devin Yoder at devin.yoder@browncountywi.gov.
Unique circumstances may arise in which an applicant wishes to petition for an amendment to the Wisconsin DNR for an ESA modification. While this process is discouraged, the Brown County Sewerage Plan provides directions on requesting such a change. The amendment must be approved by Brown County Planning staff, the Brown County Planning Commission Board of Directors, and Wisconsin DNR.
Legal Background
The indentification and protection of ESA's begins with the Areawide Water Quality Management Plan. The Areawide Water Quality Management Plan is a requirement under Wisconsin Administrative Code NR 121. Through an agreement with the Department of Natural Resources, Brown County Planning Commission was designated as the Areawide Water Qualtiy Management Agency that would administer the Areawide Water Qualtiy Management Plan (Brown County Sewage Plan) and thereby protect the designated ESA's.
ESA's Defined
NR121.05(1)(g)2c defines environmentally sensitive areas as: "major areas unsuitable for the installation of waste treatment systems because of physical or environmental constraints are to be excluded from the service area. Areas considered for exclusion from sewer service areas due to potential adverse impacts on water quality from both point or nonpoint source pollution include (but are not limited to) wetlands, shorelands, floodways and floodplains, steep slopes, highly erodible soils and other limiting soil types, groundwater recharge areas, and other such physical constraints."
ESAs are defined in the SSA plan, along with the rules and procedures for identifying necessary protections such as setbacks and stormwater/groundwater or related water management actions. A sewer service area plan outlines sewer service for 20 year time horizons. Environmentally sensitive areas should be determined with the aid of the following sources:
- Wisconsin wetlands inventory, photos, maps, surveys
- County soil surveys
- Natural Resources Conservation Service (NRCS) soils maps
- Topography maps
- Shoreland zones or navigable water corridors
- Floodplains and/or floodway maps
- DNR field inspections
- Springs inspections, inventories
- DNR and partner water quality monitoring data, standards and assessments
- Special reports on specific resources involved in or peripheral to planning areas
| ESA | ESA/Setback Requirement |
| Navigable Waterbody ESA | Navigable Waterbody ESA Setback Requirements |
| Navigable waterways based on DNR navigability determination | Land within 75 feet from the OHWM of navigable waterways (with no flood study)* |
| Floodway ESA | Floodway ESA Setback Requirements |
| Floodways identified on FEMA maps, and DNR-approved floodway maps and flood studies | 30 feet from the floodway line, or 75 feet from the OHWM, whichever is greater** |
| Non-navigable Waterway ESAs | Non-navigable Waterway ESA Setback Requirements |
| Waterways determined to be non-navigable by the DNR | 25 feet from non-navigable waterways* |
| Wetland ESAs | Wetland ESA Setback Requirements |
WDNR Wetland Inventory – Mapped Wetland Area | 50-foot buffer area |
Areas with wetland indicator soils (no certified wetland delineation has been completed) | 50-foot buffer area |
Areas with a wetland delineation completed (wetland susceptibility definitions based on NR 151.125 – (Runoff Management) Protective areas performance standard |
|
| Steep Slope ESAs | Steep Slope ESA Setback Requirements |
Land within 20 feet from the top and bottom of steep slopes that are 20% or greater and that overlap with a buffer of another ESA (like wetland or navigable stream). | 20 feet from the top and bottom of the slopes***** |
| Other Significant Natural Resources | Including (on a case-by-case basis) river and stream headwaters, groundwater recharge areas, unique woodlands, high- value wildlife habitat areas, geologic and natural area sites and wet, poorly drained, and organic soils, and areas identified in the Wisconsin Land Legacy Report and where rare plants, animals, and natural communities are known to be located as identified in Wisconsin’s Natural Heritage Inventory. |
* The 75-foot ESA setback from navigable waterways and 25-foot ESA setback from non-navigable waterways should be defined using lines that are, at minimum, parallel to the waterway. Points and straight lines may be used to define the boundary; however, in no instance shall the resultant straightened line be closer than the designated ESA width.
** The 30-foot ESA setback to floodways should be defined using points that are 30-feet from the actual ESA. The points should be connected with a straight line that is surveyed and scaled, similar to a meander line. In no instance shall the resultant straightened line be closer than 20-feet from the actual ESA.
***The wetland boundary shall be made in accordance with NR 103.08 (1m)
****Additional information for low-quality wetlands is outlined in this chapter in this chapter in Definitions, 4. Wetlands d). Low-Quality Wetlands.
*****The 20-feet ESA setback to steep slopes should be defined using points that are 20-feet from the actual ESA. The points should be connected with a straight line that is surveyed and scaled, similar to a meander line. In no instance shall the resultant straightened line be closer than 15-feet from the actual ESA.
ESA's and the Brown County Land Division and Subdivision Ordinance
In an effort to be more proactive in protecting ESAs defined by NR 121 and adopted witihin the Brown County Sewage Plan, Brown County Planning incorporated the same ESA language and protective areas (setbacks) as elements of land division reviews. This effort makes property owners and developers aware of areas that are not able to be disturbed near the begining of a project timeline so that building and site layouts can be planned accordingly.
- Brown County Land Division and Subdivision Ordinance (Brown County Code Chapter 21)
ESA Amendments
- ESA Amendment Application Manual – The application manual that provides all of the information needed around submitting sewer service area and environmentally sensitive area amendment requests in Brown County.
- Fee Schedule (May 2011) – This link will take you to the Fee Schedule for costs related to various Planning Department fees including SSA amendments.
- Online GIS Map – You are able to use the online Brown County GIS map to view approved sewer service areas and approved existing sanitary districts. The layers provide developers, surveyors, and property owners important information when reviewing and assessing the viability of a property. The sewer service area and sanitary districts can be viewed along with air photographs, property boundary, and assumed environmentally sensitive area data at the same time in order to further assist in the protection of water quality in Brown County.
Additional Information on Sewer Service Area Planning and Environmentally Sensitive Areas
- Wisconsin Department of Natural Resources (external website)
- Potential Water Quality Impacts from Lawn Care (external website)
- End-of-Season Pool Draining
