Testimony of
Kristin Taddei, Planning Advocate, Casey Trees
December 14, 2016

Before the Zoning Commission
on
The DC United Stadium Development
ZC Case No. 16-02: DC Stadium, LLC

Good evening, Commissioners. Casey Trees is a Washington DC-based nonprofit with a mission “to restore, enhance, and protect the tree canopy of the nation’s capital.” To fulfill this mission, we plant trees; monitor the city’s tree canopy; and work with decision makers, developers, and residents to encourage tree planting and protection on both public and private property. We are dedicated to helping the District reach its 40 percent tree canopy goal by 2032. As a city, we will achieve this goal when development projects protect existing trees and achieve a net gain in tree canopy. We are excited to work with the development team to ensure that trees are prioritized in the development of the D.C. United Stadium (the stadium).

The stadium will be located in the Southwest neighborhood of Ward 6, which is the ward with the lowest tree canopy in the District. By selecting a diverse tree palette and preserving space for trees around the stadium, the development team has the opportunity to increase tree canopy, showcase the best sustainability practices, and create an attractive destination for fans on game day and beyond.

It is also crucial that the design for the stadium and the land surrounding it upholds the principles of the Buzzard Point Urban Design Framework Summary. This framework, released in 2014, outlines the environmental issues present in the Buzzard Point area of Southwest, and sets goals for “improving the public realm and physical environment.” To achieve the framework objectives; work toward the District’s environmental goals; and create an appealing, resilient public green space in this community, we recommend the following:

1. Adopt a 15% tree canopy goal. Our analysis shows that this site formerly had a 15% tree canopy (Figure 1). Currently, plans show a proposed tree canopy of 3% (Figure 2). However, the development team could achieve a 15% tree canopy on site without altering building plans (Figure 3).

2. Preserve Parcel B as a public park. Architects have proposed that Parcel B be partially developed as part of this PUD. We propose that the remaining space in Parcel B be considered under this PUD and transformed into a forested park to account for lost tree canopy and help to reach 15% tree canopy cover. Preserving this green space in a conservation easement would provide a fan friendly experience and an amazing space for community members year round. It would also give trees a permanent space to grow. Casey Trees is available to serve as a conservation easement holder for this property.

3. Plant a diverse tree palette: The proposed planting plan only includes two tree species in separate installations, London planetree and Eastern redbud. Monocultures, or groups of only one plant species, reduce the resilience of plant communities and increase the risk of disease. We suggest planting a mix of at least 5 tree species around the new stadium to ensure that trees remain healthy and continue to offer benefits to this community in the future. To be truly resilient, the 10-20-30 rule for tree diversity should be followed. The rule suggests planting plans should include only 10% of any one species, 20% of any one genus and 30% of any family of trees. Casey Trees’ Urban Tree Selection Guide can be consulted as a reference.

4. Select canopy trees for the canopy garden: The development team has proposed a tree canopy garden east of the stadium. While we are excited to see trees incorporated into public space design, the tree canopy garden currently only includes Eastern redbuds, which are not canopy trees. The term “canopy trees” generally refers to trees that will be large at maturity thereby offering tremendous environmental benefits when compared to small trees. We suggest selecting a palette of large canopy trees with red fall color like red maple, black gum, and scarlet oak (D.C.’s state tree) to represent D.C. United.

5. Use advanced tree growth systems to maximize soil volume: Project renderings show trees lining the development’s interior streets and plazas. To allow these trees to thrive and provide maximum canopy benefits, install soil cells or structural soils under new sidewalks. These systems provide adequate soil volume for roots, allow soil to remain uncompacted by pedestrian traffic, and facilitate canopy growth.

Thank you for the opportunity to testify. We would be happy to work directly with the development team or provide any additional information.

Figure 1. Tree canopy previously covered 15% of the DC United Stadium site.

Figure 2. Current plans show a 3% tree canopy surrounding the DC United Stadium.

Figure 3. Our analysis shows that by transforming the remainder of Parcel B into a forested park, DC Stadium
LLC could achieve a 15% tree canopy.