Everyone Wins: A Stormwater Retrofit in a Public Park

摘要

As many other communities, the City of Rockville, Maryland struggles to add stormwaterrnmanagement (SWM) to older neighborhoods. Pollutant and erosion reduction goals vie withrnresident demands for recreation, mature trees, and open space. It is hard to convince residentsrnthat a SWM pond also can be an attractive community feature. With the new College GardensrnPark SWM pond, the City has proven that big SWM can be beautiful. Further, it can be arncommunity-wide design experience that provides a little something for everyone.rnCollege Gardens Park was built in the 1960s as a neighborhood amenity. The 2.4-hectare (6-rnacre) public park incorporated an old, spring-fed farm pond, and added play areas, a gazebo andrnpaths. A storm drain traversed the park, unconnected to the farm pond. The storm drain’s 32-rnhectare (79-acre) drainage area of mixed residential and commercial areas was 63% impervious,rnwith hardly any SWM. Canada geese had colonized the farm pond, leading to goose droppingsrnthroughout the park and algae blooms in the pond. At the storm drain’s outfall downstream,rnuncontrolled runoff was eroding adjacent backyards.rnIn the 2001 Watts Branch Watershed Management Plan, the City recommended reconstructingrnthe College Gardens Park farm pond as a SWM wet pond. It would triple the size of the farmrnpond, intercepting the nearby storm drain and routing runoff from smaller storms (up to the 1-rnyear storm) through the pond. The pond expansion would take grassed play area and causernrelocation of several park features. Although some residents embraced the new pond and parkrnupgrades, others feared loss of trees and usable open space.rnThe City spent several years exploring alternatives with the community, such as widespread LowrnImpact Design SWM. A new College Gardens Task Force spent two more years on concepts andrndetailed engineering design for the pond and park. The task force included representatives fromrnthe civic associations, the elementary school, the Department of Public Works, the City Foresterrnand Parks Manager, the City Manager’s office, and the City’s civil engineer and landscapernarchitect consultants. The process involved more than 20 public meetings. The Task Forcernwrestled with priorities and design issues, a park user survey, community selection of parkrnfeatures (such as deck materials, bridge and fountain styles, and stone veneers for walls and pondrnstructures), and landscaping plan reviews from the local garden club. By 2006, the communityrnand the City concluded that the pond reconstruction was the most practical and cost-effectivernwatershed improvement, and that both a new SWM pond and improved park features could coexist.rnAfter seven years of sometimes intense debate, the residents enthusiastically endorsed buildingrnthe College Gardens Park and Pond. It is the most collaborative and long-term water resourcesrneffort undertaken by Rockville Department of Public Works, which managed the originalrnwatershed study, the project alternatives analysis, engineering design and eventual constructionrnfor the SWM work, stream restoration and park improvements.rnThe College Gardens Park and SWM Pond project achieved more than its goal of full waterrnquality and downstream channel erosion protection, based on the State’s 2000 stormwaterrnmanagement standards. The pond incorporated two viewing decks, interpretive signage, dam andrnretaining wall designs to maximize tree preservation around the pond, and nearly 300 trees andrnshrubs. 4,000 plants were added in and around the pond for a lush wetland bench surrounding thernpond’s edge. Park improvements included a new basketball court, park shelter, and portablernbathrooms. Park paths were resurfaced and made compliant with Americans with DisabilitiesrnAct grade requirements.rnThe City completed construction in early 2010, eleven years from the first concept’s debut. Thernproject has re-designed and renovated the park, created a functional SWM facility with extensivernaesthetic and interpretive features, and installed stream restoration below the park. Achievingrnmodern stormwater control here means substantially less pollution and erosion to therndownstream tributary of Watts Branch.rnAs important, the new park exceeded everyone’s expectations and the community is extremelyrnpleased with the results. The park displays stormwater management in action in a way thatrnnobody imagined prior to this project. Other neighborhoods are now asking for similar SWMrndesigns for their parks. The College Gardens Park SWM pond is the result of a truly cooperativerneffort between residents and the City of Rockville.rnCity staff gained many insights during the eleven year process, especially due to the teamrnapproach this project required. Lessons learned included:rn1. Try to incorporate something in the proposal to suit all the users, reviewers, or critics. Itrnmay not be much, but a small feature, an added safety measure, saving one tree, or evenrnanswering a particular question keeps people engaged.rn2. Look for ways to make design features as attractive as possible. Look for chances to addrncolors, textures, veneers or concrete tinting, pavers, or other landscape architecturernfeatures.rn3. Let the community choose. The City can offer several acceptable options, but let thernresidents pick a style, color, placement or priority.rn4. Bring the varied stakeholders, interests and experts to the thinking table. Then ask themrnto listen to each other, so they understand the basics about all the issues. rnThey shouldn’trnsit at the decision table until they spend a lot of time at the thinking table.rn5. The end result has to work for all the City departments that manage the park and pond.rnCity staff buy-in is as essential as resident buy-in.rn6. Make sure the original project goals will be met (in this case, effective SWM).rn7. Take the time to build the necessary community and staff supportrn8. A good project may take years to come to fruition.rn9. Good post-construction maintenance is as essential as good initial design.