Section 5.04 Mountainside Overlay District

The 2019 GP defines the County's Mountainside Areas according to the presence of certain natural features, which include Elevation, Soils, Slopes, and Forests. These features are highly sensitive to land disturbance and development, and together, they make up large natural areas that are essential to the maintenance of healthy ecosystems in the County. According to the 2019 GP, Loudoun's Mountainside Areas contain the largest contiguous compositions of natural soils, slopes, forests, and vegetative land protected under the policies of the 2019 GP.

While protection of "Geologic and Soils Resources", "Forest, Trees, and Vegetation", and "Water Resources", might seem like separate policy initiatives, these resources and their corresponding objectives in the 2019 GP are highly dependent upon and complementary of one another in the County's Mountainside Areas. As envisioned by the 2019 GP, each resource and objective works together as fundamentally connected parts of the County's ecosystem, to the benefit of our health, welfare, safety, and sustainability.

The forested areas protected under the "Forest, Trees, and Vegetation" objectives maintain diverse habitats for wildlife, stabilize and enrich soils on slopes protected by "Soils and Geologic Resources" objectives, and support temperature moderation by providing shade and producing evaporative cooling through a natural plant process known as  transpiration . Eventually, evaporated water condenses and produces precipitation. In a natural state, as this water falls and flows down and across the mountainside slopes, it filters through soils and plants in the forested and vegetated areas, and enters the ground to recharge the subsurface water known as "groundwater", which is protected under the "Water Resources" objectives of the 2019 GP, along with  River and Stream Corridor Resources , as primary sources of the County's drinking water supply.

The Mountainside Overlay District was established to minimize disturbance or destruction to the critical ecological resources in Mountainside Areas as identified in the 2019 GP, which are defined according to the natural presence of elevation, forests, steep slopes, unstable soils, and groundwater recharge areas.

The MOD currently maps three categories of protected features: highly sensitive, sensitive, and somewhat sensitive features. These features are identified according to the mapped presence of natural topography, soils, elevation, and springs.

This interactive mapping tool shows the current Mountainside Overlay District and its existing features.

For a detailed view of individual features, click on the legend icon and zoom in on any area within the map. A separate section of standards applies to Steep Slope Areas, which may be viewed for additional context by turning on the "Steep Slope" layer in the Layer List.

This interactive mapping tool shows the Mountainside Overlay District with identified potential Ridge features.

For a detailed view of individual features, click on the legend icon and zoom in on any area within the map.

A separate section of standards applies to Steep Slope Areas, which may be viewed for additional context by turning on the "Steep Slope" layer in the Layer List.

This interactive mapping tool shows the Mountainside Overlay District with identified potential Springs features. The mapped potential Springs features depict a 300 foot buffer applied to individually identified spring points.

For a detailed view of individual features, click on the legend icon and zoom in on any area within the map.

A separate section of standards applies to Steep Slope Areas, which may be viewed for additional context by turning on the "Steep Slope" layer in the Layer List.