Piedmont Greenway Master Plan - Town of Kernersville

By designating buffers within floodplains and developing the Piedmont Greenway, the encroachments
can be better managed and open space increased, creating an amenity and reducing future watershed degradation.
Summary: Effects of Urbanization
The pattern of urbanization in the study corridor (a continuous urbanized area) is the dominant effect
of land use on the corridor’s watershed. The effects on water bodies are not so much due to the intensity of
land use as to the fact that the land is often developed without considering the natural structure and functions
of stream corridors.
many buffer recommendations should consider potential impacts associated with in-stream flood control
and water supply infrastructure including dams, modified channels and fish ladders. The above-mentioned
“buffers” are site specific to each creek and drainage channel. The needed setbacks for each creek and
watershed will have to be investigated on a case-by-case basis rather than under the broad cover of the “one
size fits all” mentality often used in these protection policies. As stated above, the function of buffers is to
reduce stormwater runoff from developed areas nearby and allow pollutants to infiltrate the soil where natural
processes mitigate and slow their rapid movement in the water body.
To preserve and enhance the watershed will require changing land use in the basin so that more intensely
urbanized areas are separate from broad, continuous streams. Floodplains should be reconnected to
streams, where feasible, and development in the floodplain should be prevented to accommodate flooding.
Such changes may take many decades, but the rapid growth of the region is already under way to alter the
urban fabric.
Efforts to reduce the impact of developed sites are shifting their emphasis to limiting imperviousness
and to dispersing and infiltrating runoff rather than collecting and treating it. Proposed methods tend to
mix urban planning and design objectives -- for example, control of sprawl and a more pedestrian-oriented
urban environment -- with site planning and design methods. Design standards must mature beyond “do
what you can, where you can.” If urban watersheds are to be managed effectively, site location and drainage
to streams need to be explicitly considered. Imperviousness may be critical in a medium-density area with
moderate slopes and an intact riparian corridor.
Land use in the study corridor is characterized by continuous urban development on the valley floors.
The primary effects on watersheds of the creeks are increased imperviousness, increased frequency of flooding,
destabilized stream configurations, disconnection of streams from floodplains and loss of riparian corridors.
Pollutants and toxicity are a secondary concern. Improving the streams in the urbanized parts of the
watersheds will require reconnecting the streams with their floodplains where feasible, and restoring riparian
cover. To do so will require changing land-use patterns in the watersheds. In new and redeveloped areas,
low-impact site design, where appropriate, will be most effective when aimed at a specific location within
a sub-watershed. Similarly, municipal urban runoff pollution prevention programs will be most effective
when they are targeted to subwatershed-scale objectives. Riparian buffers are some of the most effective
tools to meet goals of improving and protecting water quality.
Finer resolution of land-use data (GIS information) would provide a more precise estimate of land-use
acreages. A comprehensive creek coverage mapped at fine resolution would also help to accurately map
riparian corridors. In addition to analyzing patterns of land uses within watersheds and riparian corridors,
PIEDMONT GREENWAY
Final Master Plan Report 89