WeConservePA has updated its guide, Steep Slope Ordinances. Municipalities use zoning regulations to limit disturbance of steep slopes in order to prevent erosion, reduce the risk of dangerous landslides, and preserve scenic hillsides.
When disturbed, steep slopes are highly susceptible to erosion, landslides, and subsidence, which—in addition to constraining development and resource extraction—can endanger the public, degrade water quality, and damage structures. Furthermore, extensive earthwork or removal of vegetation on steep slopes can transform scenic views into eyesores.
The Pennsylvania Municipalities Planning Code (MPC) specifically describes steep slopes and grades as natural features that qualify for protection through municipal regulation. Tools employed at the municipal level to regulate steep slopes include zoning ordinances and subdivision and land development ordinances (SALDO). This guide focuses on regulating steep slopes via a zoning ordinance, because this strategy generally is the most effective at ensuring that development respects the constraints and issues presented by these slopes. (Zoning regulations enable a municipality to limit land uses to those compatible with the slopes and are usually more difficult to circumvent than SALDO requirements.)
Many municipalities throughout Pennsylvania have some form of steep slope ordinance provisions. While discussing some best practices and pitfalls to avoid, this guide also includes links to numerous examples available to the public from a range of municipalities.