Flood Control in the Capital

Many museums, memorials, and federal office buildings lie within the most flood-prone areas of Washington, DC. NCPC is coordinating federal and local efforts to improve the city’s flood defenses and stormwater management.

National Mall Levee Improvements

Improvements to the temporary closures of the National Mall levee are necessary to prevent Potomac River overbank flooding of the Mall, the Federal Triangle, and portions of central Washington. Without this upgrade, these areas will fall within the boundaries of the 100-year floodplain.

The National Park Service has proposed a removable post and panel closure system for the area near the corner of Constitution Avenue & 17th Street, NW.

Improvements to the temporary closures of the National Mall levee are necessary to prevent Potomac River overbank flooding of the Mall, the Federal Triangle, and portions of central Washington. Without this upgrade, these areas will fall within the boundaries of the 100-year floodplain.

The National Park Service has proposed a removable post and panel closure system for the area near the corner of Constitution Avenue & 17th Street, NW.

   Diagram of proposed levee system
  Overhead view of proposed post and panel closure system

The project will be implemented in 2 phases:

Phase 1: Construction of the closure system
Phase 2: Improvements to the system's appearance & integration with the surrounding landscape

NCPC approved final site development plans for Phase 1 and commented favorably on the concept design for Phase 2.

Construction of Phase 1 is scheduled for completion in November 2009.

 

Stormwater Management

NCPC examined flooding risks in the capital city after a June 2006 rainstorm shut down federal buildings in the monumental core and disrupted vital government services.

The Report on Flooding and Stormwater in Washington, DC:

  • Identifies flood risks to the monumental core
  • Outlines regulations governing flood control and stormwater management
  • Describes flood risks east of the Anacostia River
  • Recommends further actions to coordinate policymaking efforts

NCPC—along with other federal, local, and regional agencies—is currently modeling stormwater activity under a variety of conditions and developing strategies to reduce the risk of flooding.

Read more about the capital's flood risks.