Construction has begun on a major project to replace the sinking seawalls around the Tidal Basin and along the Potomac River in West Potomac Park in Washington, D.C.

The Great American Outdoors Act Legacy Restoration Fund is providing approximately $113 million for a long-needed restoration of the seawalls and sidewalks of one of the country’s most iconic landscapes.

“The Great American Outdoors Act enables the National Park Service to tackle critical large-scale infrastructure repairs and improvements in national parks throughout the country,” said National Park Service Director Chuck Sams. “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.”

The project started with a bang as a crowd gathered Thursday morning to watch the ceremonial driving of the first 80-foot piling deep into bedrock. In all, nearly 700 additional pilings will be added to create a sturdy foundation for the expanded stone and concrete seawall that will protect the area from future high tides, sea level rise, and storm surges

This crucial investment will protect some of the nation’s most iconic memorials and landscapes, including the famous Japanese flowering cherry trees, from the immediate threats of failing infrastructure and rising sea levels for the next century. Work on the Tidal Basin seawall is expected to finish in late spring of 2026, and the Potomac River construction is scheduled for completion in the winter of 2026.

Age, rising sea levels and poor drainage have severely impacted the Tidal Basin and West Potomac Park seawalls. Portions of the seawalls have settled as much as five feet since their original construction about a century ago. The settling, combined with over a foot of sea level rise, results in water flowing over portions of the seawalls twice daily during normal high tides. Despite various repairs over the decades, the seawalls are no longer structurally sound, posing a threat to visitor safety and the historic landscape, including the cherry trees around the Tidal Basin.

The repairs will include:

* Rehabilitating approximately 6,800 linear feet of seawall to extend its lifespan by approximately 100 years.

* Rebuilding the seawall with a piling-supported platform foundation to prevent settling and allow for future height extensions if needed due to rising sea levels or increasing storm surge elevations.  

* Increasing the seawall height to 4.75 feet within the Tidal Basin and to 5.50 feet along West Potomac Park to account for wind and wave conditions.

* Salvaging and reusing stones from the historic wall in the rehabilitated seawalls, where possible.

* Repairing, replacing, and widening walkways around the Tidal Basin to improve accessibility.

* Regrading landscaping adjacent to the seawalls as necessary to provide proper drainage.