Washington, D.C. and the Surging Sea
Description: A vulnerability assessment with projections for sea level rise and coastal flood risk.
Date: September 2014
Executive Summary
Washington, D.C. is likely to see record flooding by 2040 under a mid-range sea level rise scenario. A low-range scenario leads to a better-than-even chance by 2030 of flooding more than 6 feet above the local high tide line – a level topped just once in the last 70 years. And under high-range projections, there is a near certain chance of flooding above 10 feet by end of century – the highest level incorporated into our analysis.
1,350 acres of land lie less than 6 feet above the high tide line in Washington D.C. Some $4.6 billion in property value, and 1,400 people in 400 homes, sit on this area. These figures jump to $9 billion and 4,833 people residing in 1,900 homes on 2,500 acres of land under 10 feet.
The District has 21 miles of road below 6 feet, plus 2 military facilities; 1 hospital; 1 museum; and 12 EPA-listed sites such as hazardous waste dumps and sewage plants. At 10 feet, these numbers grow to 46 miles of road, 4 military facilities, 1 hospital, 3 museums, and 26 EPA-listed sites.
Sea levels are rising at an accelerating rate, and the scientific community is confident that global warming is the most important cause. Higher sea levels translate to more and higher coastal floods. To forecast future risk, this analysis integrates historic local sea level trends and flood statistics with global sea level rise scenarios, developed by a multi-agency federal task force led by NOAA in support of the recent U.S. National Climate Assessment.
This report is being released as a high-level summary of findings and methods, coincident with the online launch of a Surging Seas Risk Finder tool for the District, providing much more detailed and localized findings, and accessible via https://sealevel.climatecentral.org/ssrf/dc.
The tool includes:
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Interactive local projections of sea level rise and increasing coastal flood risk from 1-10 feet by decade;
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A zooming, zip-searchable map of low-lying areas threatened, plus layers showing social vulnerability, population density and property value;
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Detailed assessments of populations, property, infrastructure and contamination sources exposed, for each implicated county, city, town, zip code, planning district, legislative district and more;
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State- and county-wide heat maps facilitating high-level vulnerability comparisons; and
- Brief customized “fast look” reports that integrate key findings from across all analyses for each locality, and provide interpretation and context.
Detailed knowledge of vulnerability is a critical tool for communities seeking to build resiliency to the climate challenges of today and the future.