National Park Service Director Chuck Sams (left) and National Mall and Memorial Parks Director Jeff Reinbold watch the driving of the first 88-foot stake of the Great American Outdoors Act/NPS-funded Tidal Basin restoration project.
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, DC.
The Great American Outdoors Act Legacy Restoration Fund is providing approximately $113 million for the long-overdue restoration of the seawalls and walkways of one of the country’s most iconic landscapes.
“The Great American Outdoors Act enables the National Park Service to undertake important large-scale repairs and infrastructure improvements in national parks across the country,” said Director of the National Park Service, Chuck Sams“This important seawall project will remove hazards, improve accessibility and ensure the long-term protection of this world-famous landscape that attracts millions of visitors each year.”
The project began with a bang as a crowd gathered Thursday morning to witness the ceremonial driving of the first 80-foot pile deep into bedrock. In total, nearly 700 additional piles will be added to create a stable foundation for the expanded stone and concrete seawall that will protect the area from future floods, rising sea levels and storm surges.
This important investment will protect some of the nation’s most iconic monuments and landscapes, including the famous Japanese cherry blossom trees, from the immediate threats of failing infrastructure and rising sea levels for the next century. Work on the Tidal Basin seawall is scheduled to be completed in late spring 2026, and construction on the Potomac River is scheduled to be completed in winter 2026.
Age, rising sea levels, and poor drainage have severely impacted the seawalls of the Tidal Basin and West Potomac Park. Portions of the seawalls have subsided by as much as 5 feet since they were originally constructed about a century ago. The subsidence, combined with a sea level rise of over a foot, causes water to flow over portions of the seawalls twice a day during normal 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 surrounding the Tidal Basin.
The repairs include:
- Renovation of an approximately 2,000 m long embankment to extend its lifespan by approximately 100 years.
- Reconstruction of the seawall with a pile-supported platform foundation to prevent settlement and to allow for future elevation if required due to rising sea levels or increasing storm surge heights.
- Increase seawall height to 4.75 feet in the Tidal Basin and to 5.50 feet along West Potomac Park to accommodate wind and wave conditions.
- Salvage and reuse of stones from the historic wall in the renovated embankments, where possible.
- Repair, replace and widen walkways around the Tidal Basin to improve accessibility.
- To ensure proper drainage, landscaping adjacent to seawalls must be realigned as needed.
