DC s Flood of History: Recalling the Past Flooding in Washington, DC Jason Elliott Senior Service Hydrologist DC Flood Summit September 8, 2016
Those who cannot remember the past are condemned to repeat it. -George Santayana (1905) This quote has been re-interpreted in many ways since Image adapted from DeepLifeQuotes on Flickr. Used under CC BY-NC-SA 2.0 license.
Freshwater Interior / Urban Images above are public domain. --- Map OpenStreetMap contributors. Tidal
Did you know? Flood History in this region dates back to at least 1748! Per historical accounts, as a young surveyor, George Washington was blocked by flooding of the Potomac, which had been caused by the sudden runoff of snowmelt high in the Appalachians (Randall, 1998).
Did you know? Five of the seven biggest floods in the Potomac region have decadal anniversaries within a one year period (Nov 2015 Oct 2016): October 1896 March 1936 November 1985 January 1996 September 1996 Also major anniversary this year: June 2006 (flash flood) 120 years ago 80 years ago 30 years ago 20 years ago 20 years ago 10 years ago
Our history is of defying mother nature! Map #1 adapted from Mitchell, 1850. Public domain image. --- Map #2 OpenStreetMap contributors. C&O Canal Extension Slash Run Wash. City Canal Tiber Creek James Creek Canal
Our history is of defying mother nature! Map #1 adapted from Mitchell, 1850. Public domain image. --Map #2 OpenStreetMap contributors. Slash Run C&O Canal Extension Tiber Creek Wash. City Canal James Creek Canal
10/17/1942 Freshwater 3/19/1936 Freshwater Isabel (2003) Tidal 1933 Hurricane Tidal Agnes (1972) Freshwater 4/28/1937 Freshwater Fran (1996) Freshwater January 1996 Snowmelt Election Day (1985) Tidal Fran (1996) Tidal 7 7.5 8 8.5 9 9.5 10 10.5 11 11.5
The stream was nearly twice its normal width, and flowed six feet and more deep through the streets along the river front. The loss was enormous. Flood of June 1, 1889 on 14 th Street in Washington, DC. Image and quote from W.F. Johnson, 1889, a publication which is in the public domain.
Most significant flood on the Potomac to that time. Led to the Flood Control Act of 1936 Photos from Library of Congress and U.S. Naval History & Heritage Command. No known restrictions on usage.
Record flood, which still stands today Photos from NOAA Library and U.S. Naval History & Heritage Command. No known restrictions on usage.
Significant flood on the Potomac Flood of record on SB Potomac and headwaters of Shenandoah Hains Point, DC 1985 Photo from Library of Congress
Flood Frequency Study conducted by NWS Baltimore/ Washington shows major floods are fairly frequent: Location Avg. Frequency Last Major Little Falls Every 7 years 1996 Georgetown Every 8 years 2010* SW Waterfront Every 6 years 2003 Interior Flooding ** 2006/2012 * In March 2010, the peak of a moderate freshwater flood coincided with high tide, leading to exceeding major flood level at Georgetown. ** Interior flooding frequency varies at any given location. Rock Creek experiences major flooding about once every 14 years, on average. Other spots may have only seen significant interior flooding once or twice in history.
According to 2010 census data, 16.8% of persons in Washington, DC are under the age of 18. These people have never seen the Potomac in a major freshwater flood. The percentage is even higher in the suburbs. Anyone under the age of 13 was not here for the Isabel tidal flood either. Additionally, tens of thousands of adults have moved into this area during that time.
Floods are the Mid-Atlantic s #1 weather killer Turn Around Don t Drown A major flood on the Potomac is overdue Know your flood risk Questions? Jason Elliott Senior Service Hydrologist National Weather Service Baltimore/Washington jason.elliott@noaa.gov