Nobody knows where the styrofoam that washed up on Alexandria’s shore came from, but it was one part of the haul of debris that got swept up in a recent deep clean of Alexandria’s waterfront.
“We have a debris problem on the river,” said Jack Browand, division chief of Parks and Cultural Activities.
Alexandria is no stranger to flooding, but the city frequently struggles with debris not just from floods, but the common currents and tides that make Alexandria’s waterfront the region’s dumping ground.
Browand said the Potomac River’s flow pushes materials up into the city’s waterfront areas. High tides push those up into pools or riprap and they get stuck.
Browand said the city recently allocated $50,000 in funding to clean the waterfront, which paid for an initial cleaning from late December to Jan. 10. There’s enough funding for another major cleaning in the spring, likely around May, he said.
There are some areas that Browand said didn’t get the same level of treatment. If Alexandrians notice more debris in the northern portion of Windmill Hill Park, for instance, Browand said there is a contract to do planting there in the spring as part of a park renovation; it wouldn’t have been efficient to take the debris out just to re-clean that area after the planting.
“It just takes one strong storm with a northwest wind and we get a large accumulation overnight,” Browand said. “It’s consistently inconsistent with where debris lands.”
The city does implement some measures to try to cut down on debris. In the marina, Browand said there are “bubblers” that are partially submerged and create turbulence that keeps debris from becoming stuck. Even those solutions have their own problems, though, and Browand said the bubblers have to be adjusted regularly and are useless if there’s a low tide. There are also booms that keep debris out, but they’re not foolproof — they get breached and have to be manually cleared.
On a larger scale, there are several flood mitigation measures included in the city’s multi-year capital program for the waterfront. A study released last year included a review of plans for new bulkheads, a rehabilitated local storm sewer, and pumping stations.
“There’s no shortage of potential solutions, but they all cost money, time, and have environmental impacts,” Browand said. “The city’s waterfront is three miles long. That’s a lot of waterfront.”
One of the worst offenders for flooding is the riprap — man-placed stone obstacles meant to reinforce the shore and break up waves. Browand said the riprap has a tendency to collect and hold onto the debris pushed up by the tides. On the bright side, however, Browand said sometimes flooding during high tides pushes the trapped debris up onto the parks, which is unsightly but easier to clean up.
As for the styrofoam, Browand said the city doesn’t know where it came from and may never know.
“It was kind of odd,” Browand said. “It was a large concentration of it. Since then, we haven’t had that problem. Usually, there are things based on the weather, like tiny pieces of things will show up.”