It is the purpose of the Hillside Lands regulations to provide supplementary development regulations to underlying zones to ensure that development preserves the value of these areas and the public health, safety, and general welfare by insuring that development does not create soil erosion, sedimentation of lower slopes, slide damage, flooding problems, and severe cutting or scarring.

All development on lands with slopes greater than 35% shall be considered unbuildable except as allowed in Chapter 3.7.4 of the Phoenix Land Development Code (PLDC).