MALL AREA FLOODING
By and large, the biggest threat to this historic landscape is flooding. The Mall, sitting in the lowest part of the City of Washington, has experienced periodic flooding since the 1880s. In the past decade alone, Washington, DC has suffered from the effects of devastating, costly floods from both Potomac River flooding and stormwater (interior) flooding. In June 2006, heavy rains inundated Constitution Avenue and the Mall and Federal Triangle area (visualized here), causing millions of dollars of damage and forcing government facilities to close for several days. These effects are expected to intensify with global climate change. Read more below.
Working in unison in response to the 2006 flood, Federal and District agencies completed their Federal Triangle Stormwater Drainage study in 2011, concluding that cisterns could be installed under the Mall to address what they saw as an ongoing/recurring flood problem. The National Mall Coalition has taken this study, answered the initial call for flood protection, and developed it a step further in creating the Underground’s dynamic, multi-use solution.
Most visitors travel to the Mall by car or bus and struggle to find a place to park. For families with young children and those with limited mobility, parking limitations impose a particular hardship. Underground parking has been proposed for the Mall since the 1960s but never implemented. The National Mall Underground will finally realize this goal, providing easy, convenient access to the Mall’s museums, monuments, and cultural activities.
Tour buses and commuter buses clog the streets surrounding the Mall, adding to traffic congestion, blocking views of iconic structures, and polluting the air. Federal and DC agencies have been seeking for decades tour bus parking, with no success. The National Mall Underground solves both the parking and the pollution problem.
IMPROVED AND CONVENIENT VISITOR AMENITIES
Visitors to Mall museums and cultural events complain about the lack of basic orientation materials as well as restrooms and food service. The National Mall Underground offers of Mall Welcome Center with convenient access to all the necessary visitor amenities.
PUBLIC SAFETY AND SECURITY
The National Mall Underground offers key safety and security features, such as:
- Providing a safety office with first aid available to Mall visitors
- Providing for screening of vehicles – just as vehicles are screened as they enter the parking garage beneath the Ronald Reagan Building
- Serving as a safe haven for Mall visitors during inclement weather and other circumstances requiring the public to shelter in place. Although Smithsonian museums on the Mall are only between open 10:00 am and 5:00 pm, the National Mall Underground would be accessible for extended hours to serve this function.
The U.S. Department of Homeland Security, U.S. Secret Service, U.S. Department of the Interior’s Office of Law Enforcement and Security, and U.S. Park Police have evaluated the National Mall Underground proposal and found no security risks associated with the proposed underground facility. It is understood that the facility would be closed to the public and/or restricted to security/safety vehicle parking during Presidential Inaugural ceremonies, Fourth of July fireworks, and other events where security concerns are elevated. An added benefit, the Underground could serve as a Shelter in Place facility during emergencies, providing protection for Mall visitors, federal workers, and local residents alike.
LIVELY CONNECTION TO THE LOCAL COMMUNITY
The Mall is dark and lonely at night after the museums close, creating a barrier between Downtown and the emerging Southwest Waterfront neighborhoods. The National Mall Underground is a step towards helping the Mall become a livelier, pedestrian-friendly centerpiece for the local as well as for visitors to the nation’s capital.
ECONOMIC ENGINE FOR THE WASHINGTON METROPOLITAN AREA
The National Mall Underground is largely self-funding. Ultimately, revenues to build and support the facility will come from parking revenues, stormwater credits, District and/or federal government contributions, and concession and lease revenues. Cost-benefit analysis using new resilience and sustainability measures indicate a positive sustainability net present value, using measures such as non-market or societal benefits (such as lower carbon emissions and less urban heat effect).
RESPONSE TO EFFECTS OF CLIMATE CHANGE
This FEMA Flood Map below shows the continuing threat to the Mall and Federal Triangle area of Washington. The area outlined in blue, where stormwater pools, is the location of historic Tiber Creek now buried under Constitution Avenue. The overlapping red area illustrates Potomac River flooding.
City, Federal, and civic leaders have searched for solutions to control or prevent flooding and drought, but these efforts have fallen short. Current flood protection, like the recently constructed 17th Street Levee, only mitigates some of the Potomac River flooding threat, not the stormwater pooling effect.
Already the nation’s capital ranks eight on the list of cities with the biggest increases in flood days, as shown at right and documented in a report by the National Oceanic Administration. Climate change data indicates that this danger will continue to worsen in coming years.