In a comment on Wording Matters, Glenn makes excellent points about how important the definition of a greenway is and also how important the context is within which a greenway is located.
Greenway Definition: As Carrboro states in its “Recreation and Parks Comprehensive Master Plan Update” from November 2006: “…there is no single definition of a greenway…” Instead, a variety of greenway types exist.
Types of Greenways: The plan goes on to identify these types: “There are six types of greenway trail facilities that can be developed in various corridors throughout a greenway system.” It continues: “The Carrboro Greenway/Bikeway System can be comprised of each of the following types of greenway/bikeway facilities [Important for a vibrant town wanting to preserve the best of its resources]:
- I. No Facility Development
Greenway corridors that contain environmentally sensitive areas, steep topography and/or other constraints that might make greenway trail develop difficult, undesirable or even impossible. These types of corridors predominately remain in a natural state with limited trail development, if any at all. [This description matches the Bolin Creek area that Save Bolin Creek seeks to preserve.]
- II. Low Impact Uses / Limited Development
Greenway corridors that contain environmentally sensitive areas or wetlands that limit some greenway facility development to a more natural type of trail surface such as pit gravel or dirt. Trail width is typically 4-6 feet wide. These types of trails are very conducive to being enhanced with interpretive signage, so that the trail can serve as both a recreational and education use. Boardwalks may be necessary to cross through wetlands and environmentally sensitive areas. [Some areas of Bolin Creek may benefit from this type of greenway.]
- III. Multi-Use Unpaved Trail Development
Greenways corridors located in upland or non-flood prone areas can be surfaced with compacted crushed stone or pit gravel. The trail should not be used in steep topography situations and should not exceed 3% in slope. Trail width is typically 8 feet, minimum. This type of trail would not be conducive to high use, but would be intended for some mountain biking use. The trail may have limitation during periods exhibiting wet conditions. Likewise, heavily eroded segments may need to be closed periodically to allow for natural regeneration of the facility. Benches, signage and picnic tables will be sited as needed and where appropriate. [More study is needed to determine how this type of greenway might be possible within the more upland portions of the Horace Williams tract.]
- IV. Multi-Use Paved Trail Development
Greenway corridors that will be located in flood prone areas that anticipate and will support high use and will be surfaced with asphalt or concrete. Trail width is typically 10 feet, minimum. Asphalt is the most commonly used paving surface, but concrete will hold up better in areas prone to frequent flooding. Benches, signage, trash receptacles and picnic tables will be sited as need and where appropriate. [This type of greenway is what paving proponents advocate, although not taken into account are the topographic constraints that define Bolin Creek as a type I or II greenway.]
- V. On-Road Facilities: Sidewalks and Bikeways
Where off-road greenway corridors are not possible or difficult due to urban condition, on-road trails can be used. On-road greenways are comprised of sidewalks for pedestrian use and bikeways (or bike lanes) for cyclists. Sidewalk width should be 5 feet minimum. Bikeways should be striped lanes at 4 feet minimum. Bike lanes should occur on both sides of a street. [According to Carrboro then, on-road bikeways can be defined as greenways.]
- VI. Mountain Bike Facilities
Where off-road unpaved corridors are possible without damage to environmentally sensitive areas, facilities can be designed specifically for mountain biking opportunities. The trail width should be minimal at a 6’ width. The highest intense use of mountain biking should occur away from the main corridor of a multi-use trail system. Pedestrian use of these facilities should be minimal, however, should pedestrians use the mountain bike facilities, the mountain bikes should yield to the pedestrian user. Facilities for mountain biking should not be used during periods where condition are wet. It may be necessary to curtail or prohibit use in areas where regeneration of eroded areas may be necessary.” [Again, more study is needed to determine how this type of greenway might be possible within the more upland portions of the Horace Williams tract.]
Carrboro also notes other requirements for greenways: “Trails should produce minimal impact on the land; a corridor that is visually pleasing, takes advantage of natural terrain and vegetation and requires minimum maintenance.” The town goes on to say: “Terrain and elevation should not be extreme.” [And yet, the Bolin Creek valley is marked by steep slopes.] Moreover, Carrboro states: “Trails should be routed around exposed bedrock areas except where grade makes a potential crossing desirable.” [It should be noted the Bolin Creek valley is rocky and in places has exposed bedrock.]
Greenway Location Criteria: The context within which a greenway is located is also important, as Glenn points out. According to Carrboro, trail development for types II, III, IV and VI greenways should also be governed by the following: “a minimum corridor width of 100 feet (each side of streambank) or 100 year regulated floodplain (whichever is greater) should be established for all trails located in FEMA regulated floodplains. [This is not possible along Bolin Creek as the utility easement is at times less even than 15 feet wide.]
Carrboro also states that this 100+ width applicable to three different zones: streamside zone, managed use zone, and upland zone. [Bolin Creek meets the criteria for the streamside zone.]
Carrboro defines a streamside zone as follows:
“Streamside Zone
The Streamside Zone protects the physical integrity of the ecosystems that are present. Native vegetation should be preserved and existing forest canopy should remain undisturbed. This zone is very restrictive to development. Permitted uses in the zone may include flood control and bank stabilization. Other land uses that disturb the existing native vegetation and ecosystems are prohibited except for specified secondary uses native vegetation and ecosystems are prohibited except for specified secondary uses when no practical alternative exists. [Note that several practical bikeway alternatives exist, including along Pathway Drive and along Seawell School Road, both of which run parallel to Bolin Creek.] Other mitigation efforts should be undertaken to restore the native ecology of this zone. If appropriate, boardwalk trails (Type II) may be constructed in this zone.”
Accessibility: Carrboro also has this to say: “Accessibility should be considered where feasible without detriment to the ecology and environment.” [An area’s ecology and environment, therefore, cannot be significantly harmed in a desire for accessibility.] Moreover, according to Carrboro, it is only paved surfaces that “shall comply with the Americans with Disability ACT (ADA) standards whenever possible.”
Neighborhood Input: Carrboro, in addition, maintains: “Each master plan for a greenway corridor or segment of a corridor should involve residents from surrounding neighborhoods, as well as adjacent property owners and business.”
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Greenway definition matters
In a comment on Wording Matters, Glenn makes excellent points about how important the definition of a greenway is and also how important the context is within which a greenway is located.
Greenway Definition: As Carrboro states in its “Recreation and Parks Comprehensive Master Plan Update” from November 2006: “…there is no single definition of a greenway…” Instead, a variety of greenway types exist.
Types of Greenways: The plan goes on to identify these types: “There are six types of greenway trail facilities that can be developed in various corridors throughout a greenway system.” It continues: “The Carrboro Greenway/Bikeway System can be comprised of each of the following types of greenway/bikeway facilities [Important for a vibrant town wanting to preserve the best of its resources]:
Greenway corridors that contain environmentally sensitive areas, steep topography and/or other constraints that might make greenway trail develop difficult, undesirable or even impossible. These types of corridors predominately remain in a natural state with limited trail development, if any at all. [This description matches the Bolin Creek area that Save Bolin Creek seeks to preserve.]
Greenway corridors that contain environmentally sensitive areas or wetlands that limit some greenway facility development to a more natural type of trail surface such as pit gravel or dirt. Trail width is typically 4-6 feet wide. These types of trails are very conducive to being enhanced with interpretive signage, so that the trail can serve as both a recreational and education use. Boardwalks may be necessary to cross through wetlands and environmentally sensitive areas. [Some areas of Bolin Creek may benefit from this type of greenway.]
Greenways corridors located in upland or non-flood prone areas can be surfaced with compacted crushed stone or pit gravel. The trail should not be used in steep topography situations and should not exceed 3% in slope. Trail width is typically 8 feet, minimum. This type of trail would not be conducive to high use, but would be intended for some mountain biking use. The trail may have limitation during periods exhibiting wet conditions. Likewise, heavily eroded segments may need to be closed periodically to allow for natural regeneration of the facility. Benches, signage and picnic tables will be sited as needed and where appropriate. [More study is needed to determine how this type of greenway might be possible within the more upland portions of the Horace Williams tract.]
Greenway corridors that will be located in flood prone areas that anticipate and will support high use and will be surfaced with asphalt or concrete. Trail width is typically 10 feet, minimum. Asphalt is the most commonly used paving surface, but concrete will hold up better in areas prone to frequent flooding. Benches, signage, trash receptacles and picnic tables will be sited as need and where appropriate. [This type of greenway is what paving proponents advocate, although not taken into account are the topographic constraints that define Bolin Creek as a type I or II greenway.]
Where off-road greenway corridors are not possible or difficult due to urban condition, on-road trails can be used. On-road greenways are comprised of sidewalks for pedestrian use and bikeways (or bike lanes) for cyclists. Sidewalk width should be 5 feet minimum. Bikeways should be striped lanes at 4 feet minimum. Bike lanes should occur on both sides of a street. [According to Carrboro then, on-road bikeways can be defined as greenways.]
Where off-road unpaved corridors are possible without damage to environmentally sensitive areas, facilities can be designed specifically for mountain biking opportunities. The trail width should be minimal at a 6’ width. The highest intense use of mountain biking should occur away from the main corridor of a multi-use trail system. Pedestrian use of these facilities should be minimal, however, should pedestrians use the mountain bike facilities, the mountain bikes should yield to the pedestrian user. Facilities for mountain biking should not be used during periods where condition are wet. It may be necessary to curtail or prohibit use in areas where regeneration of eroded areas may be necessary.” [Again, more study is needed to determine how this type of greenway might be possible within the more upland portions of the Horace Williams tract.]
Carrboro also notes other requirements for greenways: “Trails should produce minimal impact on the land; a corridor that is visually pleasing, takes advantage of natural terrain and vegetation and requires minimum maintenance.” The town goes on to say: “Terrain and elevation should not be extreme.” [And yet, the Bolin Creek valley is marked by steep slopes.] Moreover, Carrboro states: “Trails should be routed around exposed bedrock areas except where grade makes a potential crossing desirable.” [It should be noted the Bolin Creek valley is rocky and in places has exposed bedrock.]
Greenway Location Criteria: The context within which a greenway is located is also important, as Glenn points out. According to Carrboro, trail development for types II, III, IV and VI greenways should also be governed by the following: “a minimum corridor width of 100 feet (each side of streambank) or 100 year regulated floodplain (whichever is greater) should be established for all trails located in FEMA regulated floodplains. [This is not possible along Bolin Creek as the utility easement is at times less even than 15 feet wide.]
Carrboro also states that this 100+ width applicable to three different zones: streamside zone, managed use zone, and upland zone. [Bolin Creek meets the criteria for the streamside zone.]
Carrboro defines a streamside zone as follows:
“Streamside Zone
The Streamside Zone protects the physical integrity of the ecosystems that are present. Native vegetation should be preserved and existing forest canopy should remain undisturbed. This zone is very restrictive to development. Permitted uses in the zone may include flood control and bank stabilization. Other land uses that disturb the existing native vegetation and ecosystems are prohibited except for specified secondary uses native vegetation and ecosystems are prohibited except for specified secondary uses when no practical alternative exists. [Note that several practical bikeway alternatives exist, including along Pathway Drive and along Seawell School Road, both of which run parallel to Bolin Creek.] Other mitigation efforts should be undertaken to restore the native ecology of this zone. If appropriate, boardwalk trails (Type II) may be constructed in this zone.”
Accessibility: Carrboro also has this to say: “Accessibility should be considered where feasible without detriment to the ecology and environment.” [An area’s ecology and environment, therefore, cannot be significantly harmed in a desire for accessibility.] Moreover, according to Carrboro, it is only paved surfaces that “shall comply with the Americans with Disability ACT (ADA) standards whenever possible.”
Neighborhood Input: Carrboro, in addition, maintains: “Each master plan for a greenway corridor or segment of a corridor should involve residents from surrounding neighborhoods, as well as adjacent property owners and business.”
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