Monday, November 25, 2013

The National Coalition to Save Our Mall is a group that is dedicated to preserving the National Mall in Washington, D.C., in its current form.

Anyone who knows anything about the history of D.C. knows that the Mall is highly dynamic. From the city's founding in 1789 to 1881, only the eastern half of the Mall existed. It was bordered on the north by a canal, and another canal formed its eastern boundary in front the Capitol building. It was mostly natural trees, lots of shrubs, and some open patches of grass until the Civil War, when most of the trees and shrubs were cut down to provide camping grounds for Union troops and places for cows (which fed the troops) to graze. In the 1870s, a huge series of winding gravel walkways, some gazebos, some fountains, and a huge number of trees and shrubs were planted on the National Mall to turn it into a Victorian garden. It remained that way into the 1920s.

The National Mall as we know it came into existence after the Senate Park Commission set out a master plan for the Mall in 1902. Although never adopted by Congress, the plan was immensely influential and commission members, who were someof the most respected landscape architects and urban planners of the day, fought tooth-and-nail against anything that would encroach on it. The "McMillan Plan", was their master plan was called, was slowly adopted by various federal agencies, the U.S. Commission of Fine Arts, the National Capital Planning Committee (NCPC), and other bodies.

The McMillan Plan envisioned the National Mall as a vast tapis vert or grass carpet extending all the way from the U.S. Capitol to the Lincoln Memorial. It even placed the Lincoln Memorial where it is today, and created the Reflecting Pool in front of it. All buildings had to be set back 300 feet from the Mall's centerline.

Not all of the McMillan Plan's proposals were adopted. The plan envisioned a north-south crossbar for the Reflecting Pool near the Washington Memorial, but this was abandoned. It envisioned a vast series of terraces, gardens, and colonnades around the base of the Washington Memorial, which was also never created (it would have destabilized it). Instead of the Jefferson Memorial, it planned a huge number of athletic fields, a stadium, bathhouse, beaches, and gymnasiums at the northwestern tip of East Potomac Park. A vast ceremonial plaza was planned where the Capitol Reflecting Pool is instead, and a vast complex of office buildings were to be built around the Capitol (where there is nothing today). Indeed, where the Tidal Basin is today was supposed to be filled in and a "South Arm" of the Mall created. Only a four tiny ponds were supposed to exist, to the west of this arm.

The National Mall has changed radically over time. No one envisioned the Vietnam Veterans Memorial, the Korean War Veterans Memorial, the Franklin D. Roosevelt Memorial, or the National World War II Memorial. The Rainbow Pool, created at the behest of the McMillan Plan, is gone. Maryland Avenue Southwest, once envisioned as a boundary for the Mall, is fragmented and will get even more so with the construction of the Dwight D. Eisenhower Memorial. Beginning in 1917, temporary War Department building were constructed on the north side of the Reflecting Pool. They were not torn down until 1970. Constitution Gardens was constructed on the site.

The National Coalition to Save Our Mall basically likes what they've got now. They don't want it to change one dot. The body was formed in 2000 to fight the placement of the National World War II Memorial on the axis line of the Mall between the Washington Memorial and Lincoln Memorial. They lost that battle, but they've been fighting to stop any additional changes.

Oddly, the National Coalition to Save Our Mall does favor turning the National Mall into a big amusement park. In 2009, the organization proposed adding food kiosks and small restaurants all over the Mall; building additional amphitheaters, theaters, stages, and hard-packed grounds where entertainment can be set up; constructing a large number of fountains and water parks (for the kids, ya know); adding "historic walks" with lots of signage; creating a "President's Garden" to memorialize all presidents on The Ellipse; construction of temporary memorials on sites through the National Mall; building a big National Mall Visitors' Center; permitting lots more large events (like the Folklife Festival) to use the Mall; and adding commercial (not just government) buildings.

So let's go back to Feburary 2013. The National Coalition to Save Our Mall released a plan to create a huge underground parking garage beneath the National Mall. They argue that it can serve double-duty as a stormwater run-off cistern, and hold lots of water for drinking and watering flowers. You can see their little slide show here.

The National Coalition to Save Our Mall makes three points in support of its proposal:

1) The National Mall lacks parking. Street parking is limited to 2 or 3 hours, and is eliminated during rush hour. There is too much traffic congestion caused by buses and cars searching for parking, and buses often parking in front of museums and government buildings -- obstructing views and causing security concerns.

2) The National Mall needs water for the grass, trees, gardens, reflecting pools, and fountains.

3) A 2006 thunderstorm and 2012's Hurricane Sandy led to extensive flooding of the basements of buildings on the north side of the National Mall. A 2009, a planning body recommended building a giant stormwater cistern beneath the National Mall as a stopgap measure.

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Some people have called the proposal by the National Coalition to Save Our Mall "innovative".

I don't find it innovative, as it's just doing what people have done in D.C. before (most notably over at Washington Harbour). It also has a huge number of problems. Let's talk about them:

First, adding vast underground parking worsens the traffic problem in downtown D.C. and surrounding roadways by creating a huge amount of parking space. This does not mean that the above-ground spaces (which the slide show detests so much) have gone away or won't be used. They will continue to be used. All the underground parking garage does is create more parking space, and hence more traffic on roads. It doesn't solve any problem.

Second, the National Malll is already inundated with visitors. Indeed, there are so many visitors that the quality of the Mall has been rapidly degraded. Giving more people access to the Mall worsens the problem by magnitudes!

Third, those fountains and sprinkler systems so lovingly talked about by the slideshow are fed by the public water supply system. There is no crisis in the water supply system. None. Zilch. Zippo. Plenty of water is available. There is no need for a vast cistern belowground. Indeed, the NCPC has argued that the National Park Service (NPS) needs to move away from the invasive species and exotic plants that it has planted on the Mall and toward more native plants which can weather drought far more successfully. Adding water to maintain the current unsustainable plantings is like trying to build a watermelon ranch in the desert. You can do it, but it's wasteful and dumb.

Fourth, who is going to move those vehicles in the event of a storm? Look at Washington Harbour's experience: They use the lower two levels of their parking garage as a flood control system, and cars down there are routinely destroyed when it happens. Ditto for what happens with any underground parking garage on the National Mall.

Fifth, the flooding of the Federal Triangle is NOT due to Hurricane Sandy or massive thunderstorms, but rather due to the existence of Tiber Creek -- half of which is currently buried in a sewer tunnel beneath Constitution Avenue and half of which is still flowing through the surround earth north of Constitution Avenue. In fact, the basement levels of most of the buildings on the south side of Federal Traingle leak: Every day, eight buildings -- including the Commerce Department and the FBI -- collectively pump 1.7 million gallons of groundwater from their basements because of submerged Tiber Creek. The east wing of the Smithsonian's National Museum of Natural History is pulling away from the main building because Tiber Creek is beneath it. Stormwater floods these basements even more -- not because the city sewer system cannot handle the runoff. It can: There is an overflow system that dumps stormwater directly into the Potomac River (a massive problem, BTW). The problem is the existence of Tiber Creek, which leaves the ground below and north of Constitution Avenue so wet that any large amount of rainwater will flood these buildings. And no "emergency cistern" is going to stop that.

Sixth, emergency stormwater runoff cisterns like this will be collecting water contaminated with eveything that is on the city streets nearby. This includes a vast array of petroleum products, trash, food, plant debris, human waste, dead animals, and more. Who is going to pay for the cleaning of this underground parking garage? Taxpayers. When the garage is being cleaned for a week after the storm, where do all the thousands of buses and cars go that used to use the parking garage? Right up onto the streets, which are already full of buses and cars.

Seventh, the National Mall is already in crisis over a major influx of crime. This includes vandalism, but also several armed and unarmed robberies, several beatings by two or more people, and several sexual assaults. Adding a vast, dim parking garage only worsens the problem. Look at the tremendous problems Union Station is having -- and it is above ground, well-lit, and exceptionally busy.

Eighth, this "underground parking garage-cum-cistern" seems to be a plan to avoid what the Park Service is already doing: raising the levees on the National Mall. As everyone knows, West Potomac Park, the northwestern end of East Potomac Park, and the western National Mall (past the grounds of the Washington Memorial) were created primary as flood control. Instead of a Potomac River bay about two feet deep, we have earth an average of six feet in height above the mean high-water mark. The earthen berms along both sides of the western mall are designed to hold back floodwaters. As the NCPC has pointed out, however, flat roadways act as channels through these berms for floodwaters (which defeats their purpose), and the NPS' plan to close the roads and erect walls of sandbags is a lousy one. Indeed, the berms themselves have settled, and were never really high enough to defeat the highest type of floods that the city has seen in the past. NPS is engaged in a plan to raise the berms, and address the street-as-channel problems. National Coalition to Save the National Mall doesn't like these changes. So it's proposing a flawed plan for a parking-garage-cum-cistern.... Hmmm....

Ninth, just how is transportation an issue on the National Mall? Most of the Mall is very adequately served by Smithsonian, Capitol South, and Federal Triangle Metro stations. Only the Washington Monument, and West Potomac Park lack good transporattion options. Instead of creating a problematical parking garage, why not create a Circulator bus route that begins at Smithsonian and has stops near Jefferson Memorial, FDR Memorial, Lincoln Memorial, South Ellipse, and Washington Monument? It's cheap, it uses the existing infrastructure, and can easily be adjusted to run less frequently during low levels of tourism.

Tenth, I think we also need to raise the eqarthquake stability of such a structure. After all, the western part of the National Mall is reclaimed land. During a significant seismic event, this land is going to liquify and settle. The effect on the eastern mall will be far less, but it's also not clear what the effect will be on the Washington Monument to have several million tons of water on the east side. Seismologists have already rejected any attempt to build structures around the base of the Washington Monument, for fear that they will depress the ground and destabilize the memorial (which is massively heavy and has already sunk into the soil some; a survey was going on this month to determine how much). Just how will an underground parking garage, potentially filled with water, handle a major seismic event?

Yeah, I don't think the idea of a parking garage that doubles as a stormwater cistern is a good idea...

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