National Mall flood levee project nears initial testing phase after three year delay
By Michael E. Ruane
The U.S. Army Corps of Engineers said Tuesday it plans to test the installation procedures for the new 17th Street flood levee on the National Mall this week or next week.
The levee is designed to keep flood waters from flowing north on 17th Street from the Tidal Basin and surging into parts of downtown Washington.
The levee, in part, is made of two concrete walls on either side of 17th Street. In the event of a flood, a barrier of metal posts and panels would be installed with a crane to span the street and connect with the two walls.
A corps spokeswoman said after the first installation test is complete, a second test must be scheduled for National Park Service crews to handle the procedure. The levee will eventually be turned over the park service to operate.
The project is the result of the Federal Emergency Management Agency’s nationwide review of flood-zone maps after Hurricane Katrina devastated New Orleans and parts of the Gulf Coast in 2005.
When FEMA reviewed the District’s flood zones, it concluded that the usual plans to use sandbags and Jersey barriers to prevent potential floodwaters from flowing up 17th Street were inadequate.
FEMA foresaw a scenario in which a flood could inundate a huge crescent of downtown Washington from 17th Street and Constitution Avenue east to the Capitol and south toward Fort McNair.
The new zone could have required property owners to buy expensive flood insurance, officials said. The levee was designed to satisfy FEMA and avoid that.It proposed placing the area — including Federal Triangle, the east end of the Mall and several Smithsonian museums — in the 100-year flood zone unless a better flood-prevention system was devised.