The U.S. National Park Service on Dec. 10 announced the completion of a new seawall along the banks of what is known as the Tidal Basin, off the Potomac River in the District of Columbia.
The seawall will protect not only the Japanese cherry trees from daily flooding but also the Thomas Jefferson, Franklin Roosevelt and Martin Luther King Jr. memorials.
The U.S. Army Corps of Engineers built the original seawall in the late 1800s to contain water from the Potomac River. But sea level rise and subsidence of the former wetland have progressed to the point that the area now floods with every high tide.
The rebuilding of the Tidal Basin seawall was the first phase of the project, raising it to about five feet above average the water level, giving it a deeper foundation and adding a wider walkway for improved accessibility.
The second phase of the project will focus on rebuilding the seawall along the Potomac River side, across West Potomac Park from the Tidal Basin. That phase is slated to be complete in May. According to the park service, the project is eight months ahead of schedule and about $30 million under budget.
In addition to the seawall work, the park service this spring will replace approximately 300 cherry trees lost during construction, planting a total of 426 trees, including 269 cherry trees. To ensure the new trees stabilize, the project area along the Tidal Basin and West Potomac Park will be off limits to visitors during the 2026 National Cherry Blossom Festival.