Closing The Gap: Leveraging GI to Enhance Public Improvement Projects in the City of Wilmington, DE

BACKGROUND
The City of Wilmington, Delaware (City) continues to explore opportunities to creatively manage stormwater as part of the City's Long Term Control Plan (LTCP) to implement green infrastructure (GI) as a means of source reduction in the combined sewer overflow system. The Department of Public Works (DPW) identified several publicly owned sites as prospective GI project sites to manage on and off-site drainage areas to demonstrate the benefit and value of GI to the community while also building a more robust GI program. Implementation of GI has traditionally been viewed as a regulatory challenge or financial hurdle to integrate into capital improvement projects; however, DPW has earned stakeholder buy-in through a series of collaboration projects, with other City Departments and partners, that have applied GI as a unique solution to not only address stormwater needs, but also provide additional funding opportunities and improve community spaces. DPW has worked closely with Arcadis on several projects to integrate GI as an asset to address the challenges and needs of each project site, providing benefits to all stakeholders.
OBJECTIVES / METHODOLOGY This presentation examines three case studies on different GI projects within the City that demonstrate how GI was utilized as a mechanism for intra-City partnerships leading to successful project outcomes for all stakeholders. Lessons learned and project success factors will be discussed, along with how each project contributed to the growth and progression of the City's GI program. Examples of project success factors to be examined include: - Approaching GI implementation as an asset, instead of a regulatory hurdle, resulting in more comprehensive site master planning for returning urban spaces to a more natural built environment. - Identifying and engaging with stakeholders such as intra-city departments, civic groups, governmental agencies, and the public in planning and design efforts to implement GI. - Establishing early relationships with stakeholders to create opportunities for mutual site programming and financial benefits through collaboration.
Case Study #1: Rodney Square Revitalization
Rodney Square is a historic public square at the heart of downtown Wilmington. The square is undergoing a multi-phased renovation through the Rodney Square Conservancy's Rodney Square Works initiative which is a public/private project. DPW's involvement began at an advanced stage of the design process for Phase 1 of the project with a mandate to review the site improvements and identify potential locations to implement GI as the site is comprised of mostly impervious surfaces. Phase 1 of the project, including the GI component, completed construction in June 2021. This phase demonstrates how, through careful coordination with all stakeholders, GI can be integrated into existing planned park improvements to complement the site renovation work and manage both on- and off-site runoff without impacting the site programming. Key design considerations:
1) Identifying opportunities to manage both on and off-site runoff to provide stormwater improvements for existing redevelopment of the park while also achieving LTCP goal of reducing stormwater impacts to CSO through implementation of GI.
2) Integrating GI into the existing design without negatively impacting site programming or project schedule.
3) Coordinating cost sharing of common restoration elements which allowed park funding to be reallocated to additional park and site programming improvements.
Case Study #2: Cool Spring Park Improvements
The Cool Spring Park Green Infrastructure Improvements project was initiated by DPW in partnership with the City's Department of Parks and Recreation to address nuisance flooding at the playground within the park, which is well utilized by the local community and schools. Even minor storm events rendered the playground spaces unusable and unsafe for the public. In this partnership, DPW identified the opportunity to mitigate the localized flooding at the playground, as part of the Department of Parks and Recreation's goal, and also manage the right-of-way runoff from the surrounding street and parking lot by implementing GI, which is aligned with the City's Long Term Control Plan. This project was funded through DPW's Capital Improvements Plan. The stormwater planters, rain garden, and subsurface systems completed construction in March 2020, providing the community a solution for the flooded playground and an enhanced green feature in the park. Key design considerations: 1) Partnering with the Department of Parks and Recreation to utilize park area to manage off-site runoff while providing DPW funding toward the Department of Parks and Recreation's overall master planning. 2) Integrating GI into the early phases on the master plan to unlock cost sharing opportunities and incorporating flexibility into the GI design to allow for additions of GI and other park improvements in future phases. 3) Engaging with all stakeholders to address the short-term goal of improving the playground condition to be safe for use and the long-term goal of maximizing the benefits of the site for all stakeholders' programming needs.
Case Study #3: Urban Artist Exchange (UAE) Renovation
The UAE project is a collaboration of DPW, City Fest, Inc. and the Urban Bike Project that features the redevelopment of the former Wilmington Police Department Mounted Patrol Stables in Wilmington. GI is proposed to be implemented in concert with the redevelopment of this underutilized public space which will include a cultural center and performance venue for the community. The GI will manage both on and off-site runoff, including stormwater runoff from the separate storm sewers from the two recently completed housing development projects adjacent to the site. This project is currently in the detailed design stage with a goal of construction beginning in mid-2022. The series of cascading rain gardens integrated with subsurface storage, pedestrian boardwalks, lawn areas, and performance stage will serve the community with stormwater management and multi-use park amenities. Key design considerations:
1) Collaborating early with stakeholders to develop a GI approach that both aligns with and strengthens the site programming needs of the park.
2) Utilizing the GI components as assets for attracting funding opportunities, including SRF loans and grants, not previously available to the project stakeholders.
3) Incorporating GI with other site features for mutual benefits and enhanced green benefits that provide on and off-site stormwater management.
SIGNIFICANCE OF STUDY
This series of case studies demonstrate how GI can be used beyond just a stormwater asset, but also as a collaborative solution to capital improvement funding and park renovations. Through these projects, DPW has built connections with stakeholders throughout the City and foundations for a GI program, inspiring future initiatives to standardize GI design and details, identify GI opportunities in other City parks, prioritize GI as a valuable solution for other capital improvement projects, and integrate GI education within the community.