DC’s Aging Infrastructure is NOT Ready for Climate Change — Khan Will Fix That

Washington, D.C.'s infrastructure faces significant resilience challenges due to climate change, driven primarily by its location on two tidal rivers, an aging combined sewer system, and a dense "urban heat island" effect. The District is experiencing accelerated sea-level rise and increased heavy rainfall, which frequently overwhelm existing systems, causing "nuisance flooding" in low-lying areas like Federal Triangle and forcing sewage discharge into the Potomac and Anacostia rivers.

DC’s infrastructure is not resilient to climate change:

1. Water and Sewer System Vulnerability

• Combined Sewer System Overload: One-third of the District is served by a combined sewer system designed before 1900, which carries both sewage and stormwater in the same pipes. Intense rain events, which are increasing in frequency, overwhelm this system, forcing it to discharge raw sewage into the Anacostia River, Rock Creek, and the Potomac River.

• Low-Lying Treatment Facilities: The Blue Plains Advanced Wastewater Treatment Plant, which handles most of the region’s sewage, is located at a very low elevation to allow sewage to flow downhill. Rising sea levels and tidal storm surges threaten the ability of this critical facility to operate, as rising river levels make it harder for the plant to discharge treated water.

• Stormwater Drainage Limitations: The increased intensity of storms—such as in July 2019 and September 2020—regularly dumps more water than the city's storm drains can handle, resulting in flash flooding that stalls traffic and floods homes.

2. Sea Level Rise and Coastal Flooding

• Sinking Land and Rising Water: The Potomac and Anacostia rivers are experiencing rapid sea-level rise, aggravated by the fact that the land in the D.C. area is simultaneously sinking due to subsidence. Water levels for these rivers have increased 11 inches in the past 90 years.

• "Nuisance" and Severe Flooding: Nuisance flooding, which sloshes water over roads and sidewalks during high tides, has increased by more than 300% since the 1950s. A 2015 study projected a "near-certain" chance of major flooding above 10 feet by the end of the century.

• Vulnerable Low-Lying Areas: Critical infrastructure at Buzzard Point and Federal Triangle, including federal buildings and metro stations, are at risk of inundation.

3. Urban Heat Island Effect and Energy Grid

• Intense Heat Islands: D.C. has high concentrations of impervious surfaces (concrete and asphalt) that absorb and re-emit heat, creating "heat islands" where temperatures can be up to 165°F warmer than surrounding areas.

• Vulnerable Neighborhoods: Historic underinvestment in green spaces has left neighborhoods like Ivy City, Trinidad, and parts of Southeast D.C. with limited tree cover, resulting in dangerous temperatures during heatwaves that disproportionately affect residents.

• Electrical Grid Stress: Rising temperatures and increasing heatwaves (projected to increase from an average of 7 days per year above 94.6ºF to 38 days by 2050) create immense demand for air conditioning, straining the power grid and increasing the risk of blackouts.

4. Transportation and Structural Vulnerability

• Flash Flooding of Transit: Intense storms have historically overwhelmed the Metrorail system, as seen with the flash flooding of the Cleveland Park station in 2016.

• Impervious Surface Runoff: A 4% increase in impervious surfaces between 1984 and 2010 reduced the city's ability to absorb rainwater, increasing the volume of runoff that causes flash floods