Streamlines V1, n4 (June 1996)

STREAMLINES

A Newsletter for North Carolina Water Supply Watershed Administrators

Volume 1, Number 4 June 1996

The Advantages Of Cluster Development

    Clustering is the close grouping of structures, which may share common walls, floors, ceilings, and roofs as well as other outdoor areas such as recreation and parking facilities. The most common form of cluster development encompasses residential structures in an urban context, such as townhouses, condominiums, and apartments. However, modern clustering may include multiple uses from detached residential to commercial to light industrial in a "neo-traditional" land use pattern.
    Using cluster development, construction can be concentrated in one or more areas of a site, allowing the protection of sensitive resource areas and the conservation of open space. Conventional development tends to sprawl to cover most of the buildable land with individual tracts in a "cookie-cutter" approach. Minimum lot sizes and setback requirements can create parcels that are set apart from adjacent ones with little coordination of design between them. Building footprints, combined with individual driveways and other paved areas, add up to excessive impervious cover and the potential degradation of water quality due to non-point source pollution.
    Clustering is an alternative to traditional design; it is intended to lead toward a more livable and less environmentally impacting method of land development. Clustering modifies minimum lot size requirements and/or setback distances -- sometimes a difficult task with strict zoning ordinances -- in order to conserve land. Houses are typically placed closer together and targeted away from naturally sensitive features. Individual driveways and parking areas may be consolidated to conserve even more space. The resultant open area is then available for use as a park, buffer, or wildlife habitat. Many homeowners fear cluster development, thinking it will lead to devaluation of nearby single family detached housing; but, not surprisingly, homes in clustered arrangements often increase in value faster than conventional properties because of the nearby presence of the open space and the recreational amenities available. Also, due to the close proximity of the homes and the shared open space, cluster communities tend to have more of an "old-fashioned neighborhood" type of feel to them.
    Clustering serves economic, environmental, social, and aesthetic purposes. The following points summarize some of the benefits of clustering development:

Allows for the preservation of environmentally sensitive areas
Can reduce development construction and infrastructure costs and provide for better utilization of land
Can reduce impervious surface areas, thereby reducing stormwater runoff and associated water quality impacts
Preserves rural (or neighborhood) aesthetic and social character by conserving open space
Enhances neighborhood security and sense of community through increased density without compromising privacy
Allows for more efficient (less expensive) subdivision layout by requiring less paved area and utility lines per unit
Increased open space provided usually has a direct relation to increased property values
May provide for better public or community access to a natural or recreational feature.

Buffers Help Protect Water Quality

    Early in the development planning process, environmentally sensitive areas should be identified and their boundaries delineated on development plans. Sensitive areas may include steep slopes, wetlands, flood prone areas, riparian corridors, wildlife habitat, etc. Many of these sensitive areas are located adjacent to waterways. Retaining natural or forested buffers along waterways helps preserve the important functions of these sensitive areas.
    Natural buffers have many benefits that make them valuable best management practices for protecting water quality and other resource values.
    The value of forested and vegetative buffers has been recognized in North Carolina, and they have become an important tool in the state's water quality management program. For example, the water supply watershed protection rules require that new developments maintain natural or vegetative buffers around all perennial waters with a minimum width of 30 feet for low density development and a minium 100 feet buffer for high density development. The buffer is measured landward from the normal pool elevation of impounded structures and from the bank of each side of streams or rivers (see buffer graphic in Streamlines Vol. 3, no. 1).
    No new development (i.e.: built-upon area) is allowed in the buffer. However water dependent structures or other structures such as flagpoles, signs and security lights, which result in only diminimus increases in impervious area, and public projects such as road crossings and greenways, may be allowed where no practical alternative exists.
    Runoff from adjacent developed areas should never be piped through a culvert directly into the adjacent waterbody or be discharged into buffers in a concentrated flow. To the extent practicable, stormwater runoff should enter buffers in a sheet flow manner to maximize the infiltration of runoff and allow the filtering of pollutants from runoff. If preserved and managed properly, buffers can be a valuable tool in protecting a community's water supply. For more information on vegetative buffers and state requirements, contact DEM's Watershed Technical Assistance Unit.

Buffer Benefits

Protects water quality by filtering pollutants from runoff
Provides shade to help cool water temperatures and maintains dissolved oxygen concentrations
Infiltrates and slows runoff, reducing peak flows and downstream flooding
Provides valuable habitat for fish and wildlife
Stabilizes streambanks, reducing sedimentation problems
Helps preserve the aesthetic quality of riparian areas
Increases adjacent property values
Provides areas for appropriate recreational activities

DEM Initiates New Citizen Monitoring Program

    The North Carolina Water Quality Section has initiated a volunteer water quality monitoring program to take advantage of widespread public interest in improving and maintaining surface water quality in the state.
    The program will train volunteer monitors in aspects of water quality, monitoring, and quality assurance and maintain publicly accessible databases of this information. Regular meetings, training, volunteer monitoring newsletters, and Internet resources are all planned facets of the program.
    Routine monitoring stations will be established to provide the best complement to existing DEM and discharger monitoring activities. Special studies will be developed as needed to address issues like short and long term trends in water quality, increases and decreases in submerged aquatic vegetation, and habitat quality. Initial focus will be in the Neuse River Basin and then expand to the rest of the state as the program matures.
    In order to maximize the resources available to these activities, the state is seeking donations of time, equipment, and/or services to assist with volunteer activities. Facilities that may have on-site laboratories, water quality monitoring equipment, or staff with experience in water quality monitoring that would like to share these resources with the public are invited to participate.
    If you have such resources available or are interested in this program, please contact Larry Ausley or Cathy Tyndall with the North Carolina Division of Environmental Management/Water Quality Section at (919) 733-9960.