The National Park Service has a plan for protecting the Tidal Basin in Washington from flooding/NPS file

Efforts to protect the National Mall Tidal Basin in Washington, D.C., from rising waters would revolve around rebuilding the seawalls there under a plan open for public comment through September 12.

The work that needs to be tackled includes fixing a crumbling sea wall and halting daily tidal flooding that swamps sidewalks and adversely impacts roots of some of the roughly 3,000 cherry trees that color the mall each spring with their dazzling flowers.

The Park Service will hold a virtual public scoping meeting on July 19 for the development of an environmental assessment for a proposed project to repair and rehabilitate the seawalls around the Tidal Basin and in West Potomac Park. Following the meeting, comments may be submitted on the project website.  

In the years since their construction, the Tidal Basin and West Potomac Park seawalls have significantly settled and been compromised, leading to overtopping of the seawalls in some sections twice a day during normal tidal conditions, and the water does not dissipate in a timely manner due to poor drainage, according to the Park Service.

Under the proposed project, portions of the failing Tidal Basin seawall north and south of the Inlet Bridge, as well as the West Potomac Park seawall,  would  be  reconstructed using modern concrete and stone veneer technology that will  increase  durability and  maintain  the historic character of the seawall.  The sidewalk on top of the seawall along the Tidal Basin will be replaced and regraded to provide smoother, more accessible connections to other pathways. New, stronger foundations will be able to support height extensions of the wall if it is needed due to future rising sea levels or increasing storm surge elevations.  

Information on the proposed project will be presented from 6 p.m. to 8 p.m. on July 19 via a webinar accessible at https://parkplanning.nps.gov/SeawallRehabilitation. National Park Service officials will present an overview of the project and be available for questions. Comments from the meeting will not be recorded, so formal comments for the proposed improvements must be submitted online or by mail for consideration. The scoping meeting will be recorded, and the recording will be accessible at the project website after the meeting concludes.

This virtual scoping meeting will also serve as the initial public meeting for the Section 106 process of the National Historic Preservation Act of 1966, as amended. Interested parties are invited to identify ways to avoid and minimize the potential for adverse effects to historic properties in the vicinity of the project site. The planning and environmental compliance process for the proposed seawalls project is funded by the Great American Outdoors Act.

Interested parties are encouraged to provide written comments in addition to, or in lieu of, providing comments at the public meeting. The preferred manner for providing comments is via an online form through the National Park Service Planning, Environment, and Public Comment website, used by the agency to manage official correspondence and analyze public comment in the planning process. Starting July 19, from the project website (https://go.nps.gov/seawalls), navigate the menu on the left-hand side of the page to “Open for Comment,” then open the “Public Comment Period Open until 9/12” folder. The green “Comment Now” button will take you to the online form.

Comments may also be submitted in writing to:

Superintendent Jeff Reinbold
National Mall and Memorial Parks
900 Ohio Drive, SW
Washington, DC 20024