How DC plans to address the impacts of climate change on transportation infrastructure

This summer’s extreme weather events have had a harmful impact on transportation infrastructure throughout the US. In June, streetcar service in Portland, Oregon was forced to shut down after a heatwave melted power cables. Roads cracked and buckled across Washington State, and had to be closed for repairs.

In New York City, flooding in July and September shut down subway service, with closures and delays lasting for days. Streets flooded in New York as well, and thousands were stranded on public transit during the flooding caused by Hurricane Ida. Streets and rail lines in Philadelphia were closed due to flooding from the Schuylkill River. Climate change has affected DC as well.

Ida flooded roads and knocked out power in the region. Heavy rains in September trapped cars, closed roads, and flooded the Dupont Metro station. Rains have continued to grow more intense, as the region had its wettest year on record in 2018 and its seventh-wettest year on record in 2020. Even without rain, flooding is a potential threat in the region. The Potomac River has risen by 11 inches in the last century, which is far ahead of the global average, and it is projected to rise by 3.4 feet by 2080. This makes the area in its watershed far more vulnerable to flooding. Between April 2018 and May 2019, DC had a record-setting 22 days of sunny day flooding, which occurs without rain to trigger it.

So what is the District doing to curb the damage climate change causes our transportation infrastructure? Here’s what local agencies have planned so far.

DOEE

The most comprehensive plan for addressing questions of climate resiliency in the District has been drafted by the Department of Energy & Environment (DOEE), the District agency that works to promote “environmentally responsible behavior.” DOEE conducted a series of vulnerability assessments, which it released in a report in 2016. The report concluded that, while roadways in DC are not highly vulnerable to heat right now, the possibility of 9.5-12 day long heatwaves occurring by 2080 should be considered in road construction.

Aboveground Metro lines are considered to be more vulnerable to heat than roads, with the segments of the Yellow Line between Pentagon and L’Enfant Plaza, the Orange Line between Stadium Armory and Deanwood, and the Red Line between NOMA/Gallaudet University and Brookland CUA being the most vulnerable.

Flooding is a greater risk to transit in DC than heat is, as several major roadways and Metro lines were projected to be at risk of flooding as early as 2020. In addition, the Archives Navy Memorial, Federal Triangle, and Federal Center SW Metro stations were projected to be vulnerable to flooding by 2020, 2050, and 2080 respectively. Flooding also carries a more indirect risk for transit, as the disruptions to power caused by extreme precipitation could disrupt transportation. I reached out to DOEE via email about what its plans were to address these concerns, but they could not be reached for comment.

DDOT

In 2013, the District Department of Transportation (DDOT) released its own Climate Change Adaptation Plan, which analyzed the vulnerability of the district’s transportation assets to climate change. The plan concluded that the risks to transportation infrastructure posed by increased temperatures, such as pavement buckling, premature infrastructure deterioration and the thermal expansion of joints on bridges, were low. The threats to transportation posed by flooding were judged as being more likely, as drainage overloading and failure and the flooding of roadways in low-lying areas were given a medium vulnerability ranking.

In a set of potential recommendations published at the end of the report, the plan suggested that efforts be made to increase the pumping capacity of drainage systems and that climate change be considered in the construction and design of future infrastructure.

I reached out to DDOT Acting Director Everett Lott to ask what strategies the department was pursuing to protect DC’s infrastructure from climate change. He identified that flooding poses a major threat to DC transportation infrastructure, as “today’s one in 100-year precipitation event could become a one in 25-year event by mid-century, and a one in 15-year event by the 2080s.”

To address this threat, DDOT is upgrading its culvert infrastructure, which channels water from rivers and storms under bridges, roads, and railways without disrupting traffic.

Another priority for DDOT is installing green infrastructure, including rain gardens, permeable pavement, green alleys, and urban tree canopies that will capture rainfall, reduce runoff, and absorb pollutants. It also is analyzing flood-prone areas and updating its Flood Emergency Plan to address changing conditions.

Lott also commented on the threat posed by rising temperatures in the District. He stated that both rail tracks and electrical components are at risk at times of prolonged excessive temperatures and that DDOT would consider suspending streetcar service if those temperatures posed a threat to riders and employees.

The green infrastructure that DDOT is installing would help mitigate increased temperatures as well by lowering the urban heat island effect, which takes place when buildings and roads in areas without many plants absorb high amounts of heat from sunlight.

WMATA

WMATA has developed plans for climate resilience as well. In order to reduce the Metro’s vulnerability to extreme weather events, WMATA has invested in upgrading pumping stations, securing vent shafts, and repairing interior damage within Metro tunnels. It also has measures in place to address heat waves.

Sherri Ly, a spokesperson for WMATA, stated that Metro implements enhanced visual inspections called “heat rides” when there is a risk of high temperatures that determine when rail segments reach temperatures of 130 degrees. If they do, “Metro may implement a speed restriction on rail segments above ground.”

WMATA currently relies on plans including its Severe Weather Plan and its Flood Emergency Response plan to address the effects of climate change, but it is developing a specific climate resilience implementation strategy to more directly address these concerns.