Work began Thursday on rebuilding seawalls around the Tidal Basin and Potomac River in the District of Columbia, aiming to extend the breakwaters’ lifespan by a century.
The seawalls, first built a century ago, have settled into the sediment in places and been inundated by a 1-foot rise in the sea level. Despite prior repairs, the walls are no longer structurally sound, thus requiring a more dramatic overhaul, the National Park Service said in a release.
The new walls, starting with the first 80-foot piling driven into the bedrock Thursday, will use 700 more pilings to support a platform that prevents the levees from settling.
About 6,800 linear feet of seawall is being repaired. In addition to the new foundation, the repaired walls will be higher, at 4.75 feet around the Tidal Basin and 5.5 feet around West Potomac Park, as a bulwark against wind and waves, NPS officials said.
Work is also being done around the walls. Walkways near them will be widened and repaired to make the area more accessible, and the landscaping is being altered to improve water drainage.
The construction along the Potomac River is slated for completion in the winter of 2026, while the work around the Tidal Basin is expected to be done in the spring of that year.
“This vital seawall project will eliminate hazards, improve accessibility and ensure long-term protection of this world-famous setting that attracts millions of visitors each year,” National Park Service Director Chuck Sams said in a statement.
Another feature of the area, the famous cherry trees, will grow in number once the seawall reconstruction is finished.
NPS officials removed 140 of the trees to prepare for the project and plan to plant 274 new ones once it’s completed. Japan is also planning to contribute 250 trees to D.C., although NPS officials haven’t specified whether that donation factors into their plan for 274 new trees.
The seawall reconstruction is being paid for with $113 million in federal funding, making it “the largest design-build contract in the history of the National Park Service,” National Mall and Memorial Parks Superintendent Jeff Reinbold told WTOP-FM.
• Brad Matthews can be reached at bmatthews@washingtontimes.com.