The Tidal Basin: An Endangered National Treasure
The Tidal Basin: An Endangered National Treasure
May 12, 2020 - The National Mall Tidal Basin is an extraordinary public space that plays an important role in crafting the collective memory and legacy of United States history. As part of “America’s front yard,” it is home to some of the most iconic landmarks and traditions in the nation’s capital, including memorials to Thomas Jefferson, Franklin Delano Roosevelt, and Martin Luther King, Jr., as well as the beloved cherry trees.
This cherished and deeply symbolic place is at a pivotal moment, as subsidence, daily flooding, increasing visitation, and crumbling infrastructure threaten its long-term sustainability. To ensure the National Mall Tidal Basin can meet the demands of a changing landscape, the public, and modern safety and accessibility needs, we need a bold, creative, and integrated approach respectful of the symbolism and history of this significant place.
The Tidal Basin was originally designed as a solution to flooding in the late 19th Century.
The Army Corps of Engineers first constructed the seawalls to hold back the river to allow for the land to be filled: This effort resulted in the creation of over 621 acres of reclaimed land from dredge materials and fill including the 118-acre Tidal Basin.
In the 1930’s people began using the newly created Tidal Basin as a recreational area. The parkland was developed with drives, bridle paths, swimming and boating facilities, and a bandstand. By the 1940s the site was chosen for the Thomas Jefferson Memorial. With the construction of the Jefferson Memorial, completed in 1943, the Tidal Basin began its shift from a recreational park to a setting for major memorials and monuments commemorating significant figures and events in United States History.
Washingtonian: Photograph courtesy of Herbert A. French/Library of Congress.
How the Tidal Basin Works
At high tide, the gates of the Tidal Basin were designed to open and fill the basin with water. At low tide, the water exited into the Washington Channel, and the rush of water was designed to sweep the leftover sediment away. That system no longer works today as the gates are silted shut.
Despite the gate system designed to protect it, the Tidal Basin is sinking due to the silt and water of the Potomac Flats. Twice each day at high tide, water floods the sidewalks surrounding the Tidal Basin, making them impassable for visitors, impacting infrastructure, and compromising the roots of the cherry trees. During inclement weather, circumstances are even worse as 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 and urban runoff causes increasingly high tides.
Saving the Tidal Basin
In April 2019, the National Trust for Historic Preservation announced it was naming the Tidal Basin to its portfolio of National Treasures, publicly signaling its partnership with the Trust for the National Mall, the National Park Service and American Express to mobilize the public and marshal new resources to “Save the Tidal Basin.” The National Treasure program is the National Trust for Historic Preservation’s signature advocacy program for recognizing places of national significance in need of a long-term preservation solution. This joint effort capitalizes upon the Trust for the National Mall’s deep technical knowledge and experience in advocating for the site, the National Park Service’s stewardship role, and the National Trust for Historic Preservation’s broad preservation and community outreach expertise.
The partnership led to the development of the National Mall Tidal Basin IDEAS LAB - a unique forum that will foster collaboration, encourage big thinking, and provoke innovative approaches to the profound challenges confronting this beloved cultural landscape in Washington, D.C. Unlike a design competition, which typically selects a winner with a conclusive master plan, the Ideas Lab is a platform for the exchange of solutions and approaches between designers, stakeholders, and the public. The results will showcase creative collaboration and design concepts that will enable the Tidal Basin to endure as a vital part of the National Mall for another 150 years.
New York-based firms DLANDstudio and James Corner’s Field Operations, Seattle-based GGN , Oakland-based Hood Design Studio, and Cambridge-based Reed Hilderbrand have been engaged to address the full range of environmental, ecological, historic preservation, and landscape design issues facing the Tidal Basin by working collaboratively and proposing necessary modern enhancements to the infrastructure and much needed enhancements for the visitor’s use. Challenges of this complex landscape to consider include:
Circulation—Pedestrians, Bicyclists, and Automobiles
Security—Safety and Emergency Response
Visitor Experience—Tourism, Recreation, Festivals, Urban Park, and Accessibility
Civic Stage—Expression of American Values; First Amendment Demonstrations
Cultural Landscape—Preservation and Interpretation
Connectivity—Transportation and Visual Connection Beyond the Tidal Basin Boundary
Conservation—Environmental Impact, Sustainability, Ecology, and Hydrology
Resilience—Floodplain, Climate Change, and Sea Level Rise
Infrastructure—Rebuilding and Reimagining
The participating firms are convening on May 27th to present their concepts to each other, and a curated virtual exhibition based on the Ideas Lab outcomes will premiere later this fall.