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.

STEEP SLOPE: Land comprising a ravine or lake bluff where the slope
in ascent or descent exceeds ten (10) percent from the horizontal.

STEEP SLOPE ZONE: All land which lies between the bottom of a ravine steep slope
and a line being farthest from the bottom of a ravine steep slope and ten (10) feet
from the top edge of a ravine steep slope; and all land which lies between the
bottom of a bluff steep slope and a line being farthest from the bottom of a bluff
steep slope and forty (40) feet from the top edge of a bluff steep slope.

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 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.

Use the Greatest Care when Draining Pools
City Ordinances require that swimming pools shall be drained/discharged (spring and fall maintenance) into the sanitary sewer system via a discharge hose directly into the nearest sanitary sewer manhole in the public right-of-way. Overland or ravine drainage is not permitted. Piping carrying backwash or other washwater from a swimming pool filter shall be installed as an indirect waste to the building drain or building sanitary sewer system. Piping utilized for carrying wastewater from deck drains around a pool shall be installed as an indirect waste to the storm or sanitary sewer. Leaking pools can create severe damage to the underlying soil, so repair leaks promptly.

Contact Information
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.