Weeks after Hurricane Sandy, swelling swale lingers at Roxborough Reservoir

A deluge of water from Hurricane Sandy proved a sudden test of the Philadelphia Water Department’s ongoing storm water management project around the Upper Roxborough Reservoir — and it barely passed.

Over the last few months, workers have carved away a wooded hillside off the corner of Summit Avenue and Eva Street, digging a deep swale meant to capture the first inch of storm water runoff and hold it no more than about 72 hours. Instead, the gorge filled up during Sandy, stayed that way for several days and has been slowly draining since.

By mid-week, two small ponds were left, but the swelling swale hosted a family of ducks, neighbors said. And while there is little traffic through the area right now because of work-related detours, the swale is unfenced, creating a safety hazard, said Bob Turino, who lives on Lare Street and is president of the Upper Roxborough Civic Association.

“If it was summertime, we’d have an additional 50 million mosquitos here,” Turino said.

Now the water department is trying to figure out exactly why the water collected, and has installed a pump to help speed up the drainage. PWD spokeswoman Joanne Dahme said it’s possible some of the soil in and around the swale was compacted by heavy equipment during the still-in-progress project and may have to be dug out.

“We didn’t expect it to hold so much water,” Dahme said.

The project around the reservoir is meant to manage the flow of storm water that cascades down from Ridge Avenue toward Green Tree Run, flooding streets along the way. The work to install inlets along Ridge Avenue that would carry water along new sewers on is a bit more than halfway done now, Dahme said. New sewers are in along two blocks of Shawmont, connections along two blocks of Eva Street are in progress, and the swale will be landscaped with native species when complete.

Turino said so far, the water department work hasn’t improved much of the runoff situation, and during recent rains, water still coursed down Evergreen Avenue. The Upper Roxborough group has been carefully monitoring the PWD work as well as the ongoing planning for the 34-acre reservoir area by the Natural Lands Trust.

The reservoir, now mostly dry, was created in the 1890s and was part of an early 20th-century revamping of the city’s water system that helped deliver clean water to a rapidly-growing area. By mid-century, it was outdated, and in 1962 was drained of its 147 million gallons, according to water department history.

It’s now part of the Fairmount Park system, though Turino said his group is wary of anything that would turn the reservoir into a destination, worsening neighborhood traffic and ruining its natural beauty.

“It’s not a park,” he said.

The NLT held several meetings to gather community input and may present its master plan at the URCA’s December meeting. Stay tuned to NewsWorks for details.

NewsWorks has partnered with independent news gatherer PlanPhilly to provide regular, in-depth, timely coverage of planning, zoning and development news. Contact Amy Z. Quinn at azquinn@planphilly.com.