Is Arlington Ready for the Next Flood?

Karen Vasquez with some of the items salvaged from her Arlington basement. Photo by Skip Brown

Aileen Winquist, watershed outreach program manager at the Arlington Department of Environmental Services, says the issue was on the county’s radar well before last summer’s freak storm. Arlington has been studying how to improve its storm-sewer system and has built several improvement projects since the launch of its 2014 Stormwater Master Plan. It’s added increased sewer pipe capacity in areas with a history of flooding issues, such as sections of John Marshall Drive, North Kensington Street and Ninth Road North, among others. A “green street” project on Williamsburg Boulevard, completed in 2018, introduced new canopy trees and rain gardens to collect runoff. Now engineers and policymakers are looking at the impact of climate change on the overall system.

“It hasn’t been something we haven’t been working on,” says Winquist.

Arlington officials are pushing ahead with a multipronged flood mitigation approach that could cost county taxpayers tens of millions of dollars. Various studies are in the works, and the county has launched a public education campaign—including workshops for civic associations and homeowners—to help people understand what they can do to protect their homes and businesses.

It’s a complicated endeavor, according to Arlington County Board member and immediate past chair Christian Dorsey. The county needs to upgrade its stormwater pipes, create places for runoff to flow to when those pipes fill up, and make sure new development doesn’t contribute to flooding.

But in order to be effective, the solutions must consider the entire watershed, Dorsey says. That takes time, study and a lot of engineering. Superstorms like the one on July 8 and the intensifying effects of climate change make it impossible to completely flood-proof any place, he says.

“This is one of the quintessential issues you get as a public official—something you are vulnerable to, that you can’t entirely fix by your own actions,” Dorsey says. “We have this incredible sense of urgency to move as quickly as we can.”

The Vasquez residence during the flood. Photo courtesy of Karen Vasquez

Development patterns that started in the middle of the last century have contributed to the flooding problem Arlington now faces. Back then, builders took the streams that crisscrossed the county and channeled them through underground pipes so they could develop the land.

The pipe capacity they installed was designed for the population at the time—not the higher density Arlington that exists today. Infrastructure decisions made in 1950 also didn’t anticipate more intense rainfall driven by global warming.

Now pervasive redevelopment is exacerbating Arlington’s flood risk. Driven by market demand, new homes and buildings are gobbling up green space that used to absorb runoff from heavy storms. Larger homes are occupying bigger footprints on single-family lots. Grassy areas are being replaced with impervious surfaces like roofs, driveways and parking lots.

“It’s worse in Arlington because of the density,” says Rob Groff, president of Groff Landscape Design, who lives in Rosslyn. “We have all these huge roof structures and there’s no place for the water to go.”

Still, some residents are disappointed the county hasn’t moved faster to address flooding that is leaving homeowners with repair bills in the tens of thousands of dollars, sometimes repeatedly.

Cole, of Westover Village, worries the county won’t expand more stormwater pipes because doing so is expensive and difficult. “Climate change is real; the neglect of our stormwater infrastructure also is real,” he says, noting that the water at his back door reached 27 inches high during the July storm. “The combination of the two is disastrous.”

He would like to see rain gauges installed throughout the county, and meters in storm pipes to collect more data about how rain affects different neighborhoods.

Photo courtesy of Karen Vasquez

Though Westover Village isn’t in a flood zone—it’s categorized as an “area of minimal flood hazard” on the Federal Emergency Management Agency (FEMA) Flood Map—the July flash floods left more than a dozen neighborhood homes underwater and sent rivers gushing through local businesses such as Westover Market & Beer Garden and Ayers Variety & Hardware, causing them to close temporarily.

Waverly Hills resident Keating says issues like obtaining easements (which are required for the county to access private residential property) have gotten in the way of expanding the stormwater system. “It’s taken a back burner because of the difficulty of coming up with engineering solutions,” he says. “Who wants a 30-foot ditch going through their backyard?”

Snelling, of the Arlington County Civic Federation, points out that more than half the county’s $2 million stormwater management budget is devoted to water quality issues that, while important, don’t help mitigate flooding. And though the 2014 Stormwater Master Plan includes more improvement projects beyond the six that have already been completed, she feels the process is moving too slowly. At this rate she doesn’t expect to be alive to see them built.

It doesn’t help that the goalposts keep moving. The accelerating impact of global warming is making it harder to anticipate future needs, says Demetra McBride, chief of the county’s Office of Sustainability & Environmental Management. To do that, county planners intend to identify three watersheds (out of 35 countywide) and estimate the risks/cost of inaction over the next 20 and 50 years.

“It’s to make the case for the types of investments improving the system will require,” McBride says.

Arlington County’s capital improvement plan, which is updated every two years and will be voted on in July, offers a forum for renegotiating what the county spends on flood mitigation. McBride says public hearings are expected.

Not all of the solutions will be complicated or lengthy, she says, and even some longer-term projects could offer quick relief for residents. “People don’t have to wait to see some improvement in the flooding level until all the phases are done.”

But the necessary measures will require more than larger underground pipes; there simply isn’t enough land to solve the problem that way. Another option is the installation of underground water retention areas under county parks and parking lots to hold excess water and release it slowly back into the ground.

“Nature is always going to throw you a larger storm,” McBride says, “which is why we are looking for a more elastic system.”