Washington DC's Urban Tree Canopy in 2020

The launch of Sustainable DC in 2011 established a goal of achieving a citywide tree canopy goal of 40% by 2032. To track our progress toward this goal, DDOT's  Urban Forestry Division  performs land cover assessments every five (5) years. To date, four (4) studies have been conducted, spanning the period between 2006 and 2020.

The 2020 assessment utilized high-resolution (1-meter) multispectral imagery from the Pleiades satellite constellation collected 2020 and LiDAR data from the District of Columbia also collected in 2020 to derive the land cover data set. The satellite imagery was used to classify all types of land cover, whereas the LiDAR data was primarily used to determine vegetation height and distinguish tree canopy from other types of vegetation. The land cover data set was aggregated into the below eight (8) geographies.

Despite a recent loss of 565 acres between 2015 - 2020, The city has experienced a net gain overall of 425 acres since the initial analysis in 2006. While any overall loss of tree canopy is unwelcome, there are promising signals for future canopy growth and evidence that the District's regulatory framework is effectively balancing the pressures imposed by economic development on the urban forest resources of the city.

While most major land cover types suffered a decline of UTC in the past five (5) years, the public right-of-way has seen sustained growth over not only the most recent study period, but consistently since 2006. These results validate the data driven approach applied by DDOT's Urban Forestry Division, whereby urban forest resources are prioritized and delivered to areas where opportunities are greatest.

Several phases of development have occurred in the Ft Lincoln & New Town Neighborhoods. You can explore the change, both loss and gain, since 2006 below. While a net loss has occurred, due to the fundamental shift in land use, regrowth of canopy can be seen in both the residential and commercial areas.

Oxon Run Park is the District's largest municipal park and has been the focus of many tree canopy enhancement efforts. Zoom in on the area below to reveal how the trees planted ~15 years ago by Casey Trees along Valley Ave SE have grown and contributed to canopy expansion in the intervening 15 years.

By leveraging insights from earlier land cover assessments, possible planting area can be identified and prioritized. The Wheeler Creek community in Southeast DC provides an excellent example of how land cover assessments enable land managers to direct resources to areas of greatest opportunity. This community was largely devoid of street trees in 2006. By aggressively directing tree planting resources over many years, DDOT has achieved robust canopy growth at the neighborhood scale. Observe the change over time in the Wahler Ct median, which is highlighted in the image gallery below.

Additional examples of tree canopy expansion in the ROW can be seen in the Shipley Terr SE neighborhood, where a new street trees installed nine (9) years ago are beginning to deliver important benefits to residents.

The neighborhoods surrounding the St Elizabeth's campus has undergone many substantial changes in the past 15 years. The District-managed parcel is now home to several new residential, cultural and entertainment facilities, with the development of a new hospital planned for near term development. While the federal component is now home to major federal installations. All of this activity promises to invigorate a promising region of the city, yet it has come at the cost of significant and prolonged tree canopy reduction.

In 2016, legislation designated trees with a circumference of 100" or more as Heritage Trees, and provided them protection from removal. While land owners are prevented from removing non-hazardous trees, they are able to relocate them to accommodate development interests. The first instance of Heritage Tree relocation in the District occurred at the former Fannie Mae Headquarters, located on Wisconsin Ave NW. While the site is dominated by tree loss and ongoing development activity, the mature tree relocations are also evident, along the building frontage. Zoom in to see the relocated Heritage Trees in their new locations.

Another example of Heritage Tree protections in action can be observed at the Ferebee Hope Recreation Center site, in Southeast DC. While most of the site has been cleared to make way for a new school and recreation center, a mature Heritage Tree has been shifted ~150 feet north. You can swipe the view below to see the prior site conditions, compared with the recent changes; the relocated Heritage Tree had been directly in the center of the project site, and has since been moved to the northern edge of the parcel.

The Urban Forestry Division's number one priority is to expand, preserve, and improve the urban forest. To accomplish this important mission, urban tree canopy needs to be increased across all ownership types, including public land, private property, and institutional land. This will be done by:

a.  Working with  Casey Trees  ,  MWCOG  and other NGOs in close coordination with the  DOEE  to increase tree planting on private property, with a prioiritzed focus on low density residential land

b.  Continuing to sustain full stocking of the street tree population

c. Working with fellow government agencies, including DCPS, DCPL, DCHA, DGS, and DPR, to continue strategic tree planting and maintenance on District land

d.  Increasing coordination with district agencies to review and advise on Capital Improvement Projects

e.  Completing land cover assessments at 5-year increments, and using these analyses to inform planting decisions

f.    Increasing tree species diversity when planting on District property