Dry Run

Dry Run. National Mall and Memorial Parks, Lincoln Memorial. , Most of downtown DC is at risk of flooding. The danger zone includes the museums, federal offices, residential buildings, and the spot where you're standing. The Army Corps of Engineers built a levee (raised mounds of earth that stop flood waters) around the National Mall in 1939. They left one gap at 17th Street for transportation. For over 70 years workers closed the gap with sandbags when flood waters rose. In 2014 local and federal government agencies worked together to install a modern post and panel levee closure. Once a year, the National Park Service tests this system that can close that gap within hours. As of 2024, the 17th Street levee closure system hasn't been used in a flood, but rising sea levels due to climate change make a flood event more likely each year., [Captions:] , This map shows the flood zone around downtown DC. The levee system prevents the areas in red from flooding., Steel beams are put in place across 17th Street. You can see metal plates in the sidewalk and across 17th Street covering the anchors for these beams., A crane lifts each aluminum panel and lowers it carefully into place between the steel beams., When all 27 panels are in place, the system creates a watertight barrier that completes the levee system.