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The Trust for the National Mall is teaming up with the National Trust for Historic Preservation to help #SaveTheTidalBasin:

The first phase of this three-year campaign is to design, host, and share results from an Ideas Lab presented by American Express, which will invite five world-class architecture and landscape design firms to re-imagine the future of the Tidal Basin with innovative and forward-thinking historic preservation solutions. Together, we will overcome the complex preservation issues affecting the Tidal Basin.


About the Tidal Basin

The National Mall Tidal Basin sits in America’s front yard and comprises beloved national monuments such as the Jefferson Memorial, Franklin Delano Roosevelt Memorial and the Martin Luther King, Jr. Memorial. This complex, iconic public landscape’s architecture and open space captures individuals and events that have defined our nation and celebrates cherished American values. The iconic National Mall cherry trees that encircle the basin also bring 1.5 million visitors to the Tidal Basin annually for the National Cherry Blossom Festival in just a three-week period.

The need for the Tidal Basin arose out of a disastrous flood in 1881, which devastated the District so severely that much of the southern part of city was accessible only by boat. Flooded areas included parts of the National Mall such as the Washington Monument, White House Ellipse, and the Capitol. After the flood, the Army Corps of Engineers dredged the Potomac River and used sediment from the shipping channel to fill in the tidal wetlands that are now West and East Potomac Park. In 1887, engineers installed gates at the entrance and exit of a newly formed pond (now the Tidal Basin).

At high tide, the gates open and fill the pond with water. At low tide, the water exits into the Washington Channel, and the rush of water is designed to sweep the leftover sediment away. The Tidal Basin also uses a pumping system to keep the reflecting pool at the Lincoln Memorial full of water.

Saving the Tidal Basin

The instability of the land underneath the Tidal Basin, daily flooding, and crumbling infrastructure threaten its sustainability and visitor enjoyment. The silt and water of the Potomac Flats make the Tidal Basin unstable—despite the gate system designed to protect it—and the conditions they create compromise both historic resources and visitors’ experiences. Each day at high tide, water floods the sidewalks surrounding the Tidal Basin, making them impassable for visitors and damaging the roots of the cherry trees. During inclement weather, conditions are even worse; the edge of the sidewalk is indistinguishable from the deeper waters in the basin. This flooding is expected to grow more severe in coming years as sea level rise causes increasingly high tides.

 Other issues include non-compliant ADA access, perimeter and safety challenges, substandard visitor facilities, and inadequate interpretation. And all the challenges facing the Tidal Basin are compounded by chronic annual under-funding of the National Park Service maintenance budget. The NPS National Mall Plan, a 50-year vision for the nation’s most visited national park, estimates as much as $500 million in needed upgrades at the Tidal Basin and more than $800 million in total at the National Mall, constituting the largest portion of the $11.6 billion National Park System deferred maintenance backlog.