The National Mall Underground

I’m pretty skeptical of most infrastructure construction projects, thinking them usually ill-considered and likely to create unanticipated environmental impacts. But one I support, and hope to see made a part of President Biden’s infrastructure program, is the National Mall Underground in Washington DC.

The Underground is the brainchild of the National Mall Coalition, a spunky little non-profit, and notably of its vice-president, the internationally acclaimed architect Arthur Cotton Moore. It would install a large structure under the Mall between the Smithsonian Castle and the National Museum of Natural History, theoretically invisible but for a couple of low-visibility access/egress structures. The structure would include:

·               Facilities to receive and store up to 30 million gallons of stormwater – the volume of a 200-year flood event like the one that swamped the Mall in 2006

·               Parking for a large number of tour busses and cars – the former especially contribute mightily to DC congestion and lousy air quality;

·               A field of geothermal rods to provide clean heating and cooling energy to nearby government and Smithsonian buildings;

·               A visitors center serving all the Mall’s museums, monuments, and public buildings, perhaps including exhibit space to augment what’s provided by the existing museums;

·               A “shelter-in-place” facility for tourists and others during inclement weather or other disaster; and

·               Cisterns to receive, store, and distribute groundwater to irrigate the Mall’s greenery.

It wouldn’t be a huge project – its cost is estimated to run about $300 million – but its location would make it a highly visible one, a symbol of the country’s determination to put the dark years behind us and build for the future. And the needs it would meet are serious ones. Flooding from interior sources as well as tidewater and the Potomac and Anacostia Rivers has been described as an “existential threat” to the Smithsonian museums, federal buildings, and National Archive facilities around the Mall, and nobody’s come up with better solutions than higher levees along the rivers and pumping plants to shoot floodwater over them. No better solutions other than the Underground, that is, which actually was inspired by the unrealized recommendations of interagency committees over the years.

Such committees have looked at the Coalition’s proposal too, and generally been supportive but unable to overcome the bureaucratic obstacles to doing anything. Governance of the National Mall is divided among half a dozen federal agencies, the District of Columbia government, and the Smithsonian. Nobody seems able to make the thing happen.

The Corps of Engineers has examined the Coalition’s proposal and concluded that:

The Underground offers an innovative, multi-purpose potential alternative for stormwater retention and flood risk management on Constitution Avenue and in the Federal Triangle area. Concurrently, it could address the documented need for tour bus parking, as well as provide a tourism visitor center, geothermal energy, and irrigation for the National Mall turf grass and gardens. Additionally, revenue potential from parking fees and water credits may offer self-financing opportunities that attracts a public-private partnership.

But the Corps can’t take action by itself, and neither can any other federal agency. Direction is needed from Congress, and maybe from the President, who after all lives on the Mall with his family, and whose basement (he wasn’t in residence then) was flooded in 2019.

Some of my historic preservation colleagues have asked me how such a project could possibly be permissible under the National Historic Preservation Act, given the requirement of that law’s Section 106 that federal agencies “take into account” the effects of projects on historic places like the Mall. I respond that “take into account” does not mean “don’t touch” – as the whole history of Section 106 review since the law’s enactment in 1966 vividly documents. A proposal to build the Underground would trigger consultation among interested parties – negotiations aimed at a Memorandum of Agreement as to how the project would be carried out; I don’t see much in the way of legitimate obstacles to achieving such an agreement. Of course, what’s “legitimate” to my eyes may be very unlike what’s “legitimate” to others, which is precisely why Section 106 review has multi-party consultation as its centerpiece.

But maybe I’m wrong. I invite everyone who’s interested to take a look at the Coalition’s Underground web page -- National Mall Underground | National Mall Coalition – and let me know of any objections.

Or additional ideas. For example, what might the visitors center contain in the way of fixed exhibitions? It’s been suggested that the workings of the Underground – its automated parking, its circulating groundwater cisterns, its geothermal plant – might be on display as examples of green engineering, and this seems to me a good idea. Perhaps the visitors center might also be a place to acquaint people with the indigenous Piscataway, Pamunkey, Nanichoke, Mattaponi, Chickahominy, Monacan, and Powhatan peoples of the area. One can learn about them at the National Museum of the American Indian on the Mall, but one has pretty much to go there by intention. A treatment of indigenous history and culture in the Underground’s visitors center might help all visitors meditate on our use and misuse of the lands occupied by the predecessors and victims of colonial governance. I’m sure there are lots of other good ideas out there, and the Coalition’s very keen to learn about them.

Incidentally, a lot of interesting ideas were discussed, leading to some refinements in the Underground’s design, during a presentation the Coalition made to the American Institute of Architects (AIA) last June; see https://www.nationalmallcoalition.org/2020/06/webinar-on-national-mall-resiliency-draws-record-audience-for-aia/ .

Take a look, and let me know what you think. And if you like it, you might mention it to your Congressperson. Thanks.