March 29, 2017

Aidin Sarabi
District Department of Transportation

Re: Rhode Island Avenue NE Streetscape Project – Phase I

Dear Aidin Sarabi,

Casey Trees is a Washington, D.C.-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 government officials, developers, and residents to prioritize the District’s trees and to encourage tree planting on both public and private property. We are dedicated to helping the District reach its 40 percent tree canopy goal by 2032 – an achievable goal only if the District actively grows the city’s urban forest. The streetscape improvement project provides an opportunity to expand tree canopy and improve the pedestrian experience on Rhode Island Avenue and contribute to the Districts’ numerous environmental goals.

The District Department of Transportation’s (DDOT) 2014 master plan for Rhode Island Avenue NE affirmed this street as an essential corridor for commuters and destination for residents and visitors. During the planning process, community members requested improved tree box design and more street trees. The addition of streetside bioretention, better tree box designs, and 65 additional trees in the Phase I plans for Rhode Island Avenue are moves we applaud.

In addition to these steps, we urge DDOT to consider the following for its Phase I designs:

Prioritize Large Trees
Streets lined with large shade trees have a traffic calming effect, keeping drivers and pedestrians safer. Plant large trees to cool streets and maximize environmental benefits. Select medium or large trees for all tree boxes or planting strips with at least 1,000 cubic feet of soil.

Maintain Tree Diversity
Planting multiple tree species along Rhode Island Avenue will increase resilience, helping to achieve one of the District’s top goals in its Climate Ready DC plan. Therefore, we applaud DDOT’s commitment to planting 17 different tree species along the corridor. However, we recommend alternative tree species for two of the proposed street trees (Figure 1). Casey Trees’ Urban Tree Selection Guide can also be consulted to identify street trees ideal for Rhode Island Avenue.

Include Trees in Bioretention Areas
Bioretention areas with at least 1,000 cubic feet of soil should include trees to absorb excess stormwater. Trees in bioretention areas further slow stormwater runoff and reduce pollution through interception, evapotranspiration, and nutrient removal. Casey Trees’ Urban Tree Selection Guide may be consulted to select trees that perform best in bioretention areas.

Protect Existing Trees
During construction, ensure that all street trees scheduled to remain are adequately protected. Adding tree protection fencing will prevent damage from equipment and debris. Install clear signage and metal fencing beyond the critical root zone of any trees on or near construction sites, as specified on sheet 41 of the phase 1 planting plan (DWG NO. 608.10).

Thank you for the opportunity to comment. Casey Trees would be happy to work with you to provide tree-related analyses for the Rhode Island Avenue Streetscape Improvement Project. If you have any questions about these recommendations, please feel free to contact me at ktaddei@caseytrees.org.

Sincerely,
Kristin Taddei
Planning Advocate