Wilson Bay Stormwater Best Management Practice and Sturgeon City
Sturgeon City an environmental education center and recreational park,
is under development in Jacksonville, NC. The water-front park is
located at the site of the City of Jacksonville's Old Waste Water Treatment
Plant. In March 1998, the plant was taken off-line and decommissioned.
Although the plant lost its utility as a wastewater treatment facility, the
treatment tanks and physical structures at the site remained. Rather than
demolish the plant, the City launched a comprehensive effort to renovate
the site into an environmental education center focused on the plight of
endangered species. Short-nose sturgeon, which once inhabited the adjacent
New River, were selected as the focal point of the environmental education
effort. In support of this effort, Art Rice, NCSU School of Design,
challenged a group of students to develop alternative concept ideas for the
site. The students developed their personal vision for the site and
presented these ideas to the City's Council and the Sturgeon City Advisory
Committee. These concept drawings helped Council and Advisory committee
members visualize the potential value of establishing the education center
and park on the site.
Wilson Bay Stormwater Best Management Practices
Over the last two years, water samples collected from the urban streams draining the adjacent Wilson Bay watershed have yielded data that consistently document high levels of nitrogen, sediment and bacteria. These pollutants are conveyed in stormwater runoff as well as during baseflow. The Bayshore area is an existing neighborhood, built in the 1940's, hence opportunities to mitigate these impacts are expensive to implement. More importantly, retrofit requires altering the existing neighborhood environment, which can be traumatic for the citizens. Given these issues, the development of the stormwater treatment plan requires an approach that not only addresses the pollutant and transport mechanisms but also is inclusive of the neighborhood citizens' concerns.
The mission of Extension is to work locally to apply science and technology in the community to develop solutions to problems. In design, a charette is a time-honored tradition of intensive, short ‚term brain storming to develop collaborative solutions to a problem. The issues related to storm water mitigation were addressed with the Bayshore neighbors using the charette approach so that they designed the stormwater plan to fit their neighborhood.
The Wilson Bay Community Stormwater Design Workshop was held from 10:00AM till 1:00PM on Saturday, December 4th, 1999, at Thompson Elementary School's Library and Cafeteria. The agenda included a thirty minute "get acquainted period in which residents could arrive, get registered and be oriented by the staff. Several speakers spoke briefly about the charette process, on-going research projects, then presented technical water quality data and BMP alternatives. Armed with this information, the participants broke into small groups (4-6 people) and, working on maps of the area, developed "plans" of BMP recommendations. This was followed by a general discussion of the groups' recommendations. The workshop was attended by more than fifty people and produced 9 watershed plans including drawings, sketches and written notes of areas of flooding, trash, possible pollution sources, and locations for specific BMPs.
The stormwater team compiled the community's suggestions and ideas and in conjunction with Town officials discussed the feasibility for each recommendation using the following criteria.
1) Water quality treatment potential.
2) Land ownership / potential for easement, purchase, participation.
3) Space available for BMP.
4) Implementation natural factors such as topography, soils, vegetation, water adjacency.
5) Implementation cultural factors such as structures, pedestrian traffic, exposure, public safety.
6) Distribution throughout the watershed.
7) Fit with companion recommendations.
The results of this work generated the following recommendations which are compiled on a site by site basis.
1) Government Complex on College Street:
County plans to pave the parking lot are contradictory to the efforts to reduce stormwater loads as a component of the restoration of the Bay. Plans for extensive grading, tree removal, and installation of impervious asphalt cover will increase pollutant loading as well as total volume and peak runoff. It is recommended that pervious pavers be used and bio-retention treatment area be incorporated into low corner of the lot to clean and retain runoff water.
2) Vacant lot across from Government Complex:
This area has tremendous potential to treat stormwater as it is a naturally low depression that would easily accommodate a bio-retention facility, but more importantly its position in the watershed would allow to treat much of the stormwater drainage from above Old Bridge Street. However, the Team was made aware of the fact that this lot is extremely valuable, and so more than likely could not be used for stormwater infrastructure. The feasibility of using this site may improve by incorporating multiple use facilities for a park, open space, or meeting area as well as an stormwater education demonstration facility.
3) Thompson Elementary School Playground:
Stormwater drainage from approximately 5 acres of rooftops and paved areas drains through the stormwater ditch on this site. Two planted areas of approximately 0.5 acres could provide the necessary treatment. Potential locations and types recommended are a bio-retention garden adjacent to the sidewalks, and a linear constructed wetland garden to hide the sewer pipe in the lower portion of the play area. Walks, swings, signs, and benches could increase the use of this space as well as support educational opportunities. A partnership with the County Schools systems would be needed. The potential of this site to reduce peak, total volume as well as pollutant loading to the adjacent stream is very good.
4) Privately Owned Wooded lots along Court, Wardola, and Ford Streets:
These lots are low and offer little development potential but a significant amount of restoration potential for stormwater treatment. These areas should be incorporated into the wetland restoration plans for the Bay area.
5) Residential Lot at intersection of W. Bayshore and Warlick:
This area was frequently identified by the workshop participants because of its critical location. It is estimated that more than 20 acres of the watershed drain to this area. The are is not large enough for a bio-retention facility, but the reviewers felt that the first 1" of stormwater runoff could be treated if a stormwater wetland were installed. An association with the homeowner needs to be established. Issues of long term maintenance and land ownership will need to be addressed.
6) Park on Bayshore at the Bay:
This area is very low in the watershed so offers little treatment potential. Additionally adjacent homeowners have expressed negative reactions to "naturalized" treatments and exhibit a propensity for lawns, bulkheads and rip rap. The site assessment by the reviewers generally yielded the opinion that little opportunity exists in this location.
7) Stream, East Bayshore side and adjacent to Marine Base:
Land above the Park Street and E. Bayshore intersection could be flooded using a simple water control structure to re-establish wetland functions. Elevation assessment is needed to determine the extent of flooded area, but the potential for treatment is good using land that is currently not developed or managed. Landowners on both sides of the creek would need to be amenable to providing a conservation easement and long term maintenance issues would need to be addressed.
8) Street IslandăBayshore, Park, and Stratford:
This area could be excavated to make a bio-retention area that could process runoff water from all three streetsăif they were re-graded to drain to this area. An existing Crape Myrtle would need to be relocated, curb and gutter removed, under drains installed connecting to the storm water infrastructure as well as the rest of the bio-retention area structure. An existing sewer line would need to be relocated or designed around. Putting a bio-retention area at this site makes good use of existing public property. Total drainage area and depth to ground water need to be assessed to determine volume treatment potential.
9) Street IslandăBayshore and College:
Existing Crape Myrtle and Cedar trees are too valuable and large to be removed or relocated. Recommend that the upper portion of the island be retrofitted as a bio-retention area and that street drainage be directed to that portion of the island for treatment. This area could provide additional treatment for water draining from New Bridge St.
10) Woodmen of the World Parking Lot:
This area appears to be a highly underutilized parking facility that has potential to be an excellent site for stormwater treatment. Recommend that the back side of the lot be used as a bio-retention facility, and the remainder of the lot be refurbished using pervious material.
1) Encourage the use of pervious pavements whenever possible.
2) Reduce the use of curb and gutter whenever possible. The use of concrete swales or flat aprons on the road edge helps reduce road-edge crumbling and increase the appearance of a "neat" edge.
3) Center - inverted streets can be used to direct water to areas for filtration and capture without having to use road edges or curb and gutter.
4) Strongly recommend commissioning a water resource study to develop a plan to help direct stormwater and water resource management.
Wilson Bay Water Quality Iniative