In order to protect the unique geology and natural ecosystems of the ravines and lake bluff, the City of Highland Park adopted a Steep Slope Ordinance. This ordinance establishes special regulations for demolition, grading, construction, and landscaping activities in and near ravines and the lake bluff. In addition, the ordinance requires property owners to properly maintain the ravine channel to keep it free of large debris as well as maintain storm drainage lines to prevent water leakage which may cause erosion along a ravine edge or the lake bluff. A summary of the regulations established by the Steep Slope Ordinance is included in this flyer.

What is a Steep Slope Zone? Steep slopes are found throughout the ravines and lakefront community of Highland Park. There are two types of steep slope zones: ravine steep slope zones and lake bluff steep slope zones.

No construction zone. New construction is generally not allowed in steep slope zones. However, the Director of Public Works can issue exemptions for retaining walls and other structures necessary to stabilize a slope. The Director may also approve steps, bridges, and fences that do not obstruct the flow of light and water. In addition, existing structures which extend into a steep slope zone can be rebuilt if damaged or demolished, and can be expanded or remodeled if the structure footprint is not increased within the slope zone. Finally, if the regulations create an undue hardship for a homeowner, the Zoning Board of Appeals can grant a variance.

Maintenance and restoration of Steep Slope Zones. Ravine homeowners, (as well as the City in cases of City-owned property) must remove debris that can block a ravine channel and cause diverted water to cut into the side of the ravine. Homeowners are prohibited from dumping lawn clippings or other waste onto the sides of ravines and the lake bluff since this waste smothers underlying vegetation vital to slope areas damaged during work in and around ravines or the lake bluff.

Storm water drainage. Homeowners must maintain stormwater drainage lines. Drainage lines which dump stormwater from roof drains onto the side of a ravine or the lake bluff can be cause significant erosion which could result in significant slope failures. To protect the slopes, stormwater must be conveyed to a storm sewer or to the bottom of a ravine or lake bluff.

Location and drainage of swimming pools. Swimming pools must be set back 20’ from the top edge of a ravine and 50’ from the top edge of the lake bluff to protect the slopes from potential leakage over time. Swimming pools must be drained slowly. If possible, the water must be conveyed in a minimum 3" diameter pipe of hose to a public storm sewer with a pumping rate not to exceed 200gpm. If a storm sewer is not available, such discharge pipe or hose must be extended into to the bottom of the ravine or bluff and directed downstream in such fashion as to avoid erosion at the bottom or tow of ravine or bluff slopes, and in such event the maximum pumping rate shall not exceed 100gpm.

Landscaping. Because the root systems of even very small trees can help stabilize slopes, tree removal within a steep slope zone must be approved by the City Forester. For more information contact the City Forester at (708) 926-1149.

For a complete copy of the Steep Slope Ordinance or for additional information, please contact the Director of Public Works at (847) 432-0808, or contact the Department of Community Development at (847) 432-0867.