Climate change makes DC even swampier

Emily Mulderig

As a typically hot and sticky DC July came to a close this summer, I learned that it had been the hottest month recorded by humans, ever. Worrying as this fact was, I can’t say I was shocked. Growing up in the twenty-first century, I am unphased by wacky weather, extreme highs and lows, and frequent news of devastating natural disasters. But I couldn’t help but wonder what’s in store for our city as the climate crisis worsens and its effects become clearer.

So far this summer, each month in DC has been hotter than the past average and as of late August, there were 51 90+ degree days, which is more than two weeks over the average amount. According to Jason Samenow, the weather editor of the Washington Post, “once you get over 50 [90+ degree days], you’re kind of in rare territory. So the heat was fairly persistent, and at times intense, and the humidity also just made that hot air feel even hotter.” Humidity levels in the DC area have increased five to ten percent since 1970, and that extra moisture in the air can make for more intense rainstorms.

According to Samenow, “the heaviest precipitation events and the heaviest downpours may become more extreme as we head to the future just because the hot air accelerates or speeds up evaporation.” The more water there is in the air, the more intense the storm. This summer brought a few memorable rainstorms, including the morning of July 8th, when the DC area got a month’s worth of rain in an hour. Social media was flooded with images of rain pouring into metro stations and rushing through the streets. Water surged out of overflowing drains, caused traffic stoppages on busy roads, and even caused leaks in the White House basement (you won’t be surprised to hear that Wilson faced severe flooding too). Unfortunately, heavy rainstorms in DC have a much deeper effect. 

More than one-third of the District uses a “combined sewage overflow” system, designed before 1900. In dry weather, a barrier blocks sewage water from getting piped out to the rivers. But on rainy days, sewage water is combined with the extraneous rainwater, causing both to flow over the barrier, emptying a combination into the Potomac River, Anacostia River, and Rock Creek. 

Fortunately, DC Water’s Clean Rivers Project is aiming to contain and clean wastewater before it reaches these bodies of water, thus combating the negative effects of increasing rainfall. Their technology includes more than 18 miles of underground tunnels, rain gardens, and permeable pavement which will prevent 98 percent of the sewage that would otherwise be entering the Anacostia River from doing so. It should keep 2.8 billion gallons of the potential sewage/stormwater combination from entering our waterways. Phase one of the project began in 2011 and the rest should be built by 2022. 

The rising of the Tidal Basin has caused significant erosion and flooding. Visitors who came to see the cherry blossoms this year found segments of concrete crumbling and submerged underwater. Plus, the average peak bloom date of the cherry blossoms has been slowly becoming earlier due to warmer temperatures. 

This summer was not a record-breaking year, per se, but it fits the trend that scientists have been observing in DC for several years now. So what can DC expect to see in the future? Temperatures will continue to get warmer. Humidity will continue to rise. Rainstorms and downpours will get more and more intense. Hopefully, there will continue to be more and more initiatives like the Clean Rivers Project that help our city cope with the effects of climate change and lead us to a greener, more efficient, and a more environmentally friendly future.

Courtesy of Creative Commons