Steep Slope Protection

The rolling hillsides of Chester County offer a significant environmental function of providing wind breaks and stormwater management. Slope management allows a municipality to protect areas of steep and moderate slopes from indiscriminate disturbance. Uncontrolled disturbance of steep slopes and vegetation on slopes can result in:

A variety of approaches to steep slope management are available to local governments. Applicable to all of Chester County's landscapes, municipalities with undeveloped slope areas within their boundaries should consider developing slope protection regulations. Such regulations are generally located in both zoning and subdivision and land development ordinances.


Steep slope preservation tools are associated with the following advantages:


Steep slope preservation tools can be associated with the following limitations:

How to Use This Tool

Provisions for slope management are typically included in both the municipal zoning ordinance and the subdivision and land development ordinance. Before such provisions are drafted, a policy basis for slope management should be established in the comprehensive plan and/or open space plan. Ideally, sloped areas within the municipality should be inventoried (with appropriate mapping), but such inventory may not be necessary if zoning and subdivision ordinance definitions are clear. Most municipalities distinguish between "moderate slopes" of 15% or greater and "severe slopes" of greater than 25% slope. The applicant will be required to identify steep slope areas in the site plan and demonstrate how such areas will be protected from disturbance or where disturbed, how such disturbance will be mitigated.

After a policy basis is established, a municipality should amend its zoning ordinance to include steep slope land use and maximum disturbance provisions. The subdivision and land development ordinance should also be amended to ensure that slopes are identified and mapped during the plan review process and that disturbance of slopes during the construction process is managed to minimize erosion and sedimentation.


Most Chester County municipalities currently regulate slopes. The following examples illustrate the approached taken by municipalities:

Related References

The Pennsylvania Municipalities Planning Code (Act 247) specifically allows for protection of slopes. Section 603(b)(5) indicates that "zoning ordinances may permit, prohibit, regulate, restrict and and preservation of natural resources". Section 605(2)(iii) is more specific, stating that zoning ordinances may regulate, restrict, or prohibit "uses and structures at, along, or near...places of relatively steep slope or grade, or other areas of hazardous geological or topographical features."

The Pennsylvania Code, Title 25 Environmental Protection, also addresses steep slope protection.

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