Towns immersed in storm water tales

Tactics taught to minimize flooding

By Steven H. Foskett Jr. TELEGRAM & GAZETTE STAFF

BLACKSTONE— On any given night, at any Planning Board meeting in the area, there is bound to be talk of storm water management.

As development in the area increases and open space shrinks, where that drop of rain goes after it falls from the sky is an increasingly bedeviling problem for planners, residents, environmental activists and developers, and the Blackstone River Coalition hosted a conference at the Blackstone Public Library yesterday to discuss the challenges communities face.

Of course, the area saw about as much storm water as it will see for decades during the devastating October storms that dropped more than a foot of rain in some places and caused the Blackstone River to overflow in several towns along its banks. Joseph Buckley, assistant director of sewer operations for the Worcester Department of Public Works, and N. Kim Wiegand, town engineer in Lincoln, R.I., offered case studies of how storm water management functioned during the rains and flooding.

Overall, Mr. Buckley said, he felt Worcester got off easy during the October storm, although there were problems. A complex system of culverts and hundreds of miles of sewer pipes helped the city avoid a flooding disaster, and Mr. Buckley said improvements made after the city’s last disastrous flood, in 1955, have held up reasonably well.

He said the DPW received more than 200 complaints from residents and businesses during the October storms, mostly pertaining to cellar flooding and sewage backups, but said the number of people affected was probably much higher.

“People probably saw railway cars floating around on television, and figured, ‘Why bother?’ ” Mr. Buckley said.

As a result of lessons learned from the storm, Mr. Buckley said, the city is working with homeowners in certain areas to install one-way valves that will prevent sewage backflow in a flood.

He said the city keeps a close eye on its sewer system, and cleans out its catch basins on a two-year cycle. He said the DPW closely monitors 50 to 55 “choke points” on the sewer grid to make sure things are operating smoothly. For example, he said, a tree branch, a tire, or a shopping cart blocking a culvert on a normal day have the potential to cause the same amount of flood damage as a major storm.

Ms. Wiegand said Lincoln, a town of about 18,000 people near Providence, experienced severe flooding, and the rains blew out a small state road that left a subdivision cut off from the rest of the town. Problems the town encountered included flooding because of catch basins that had been clogged by grass clippings, and disputes over control of a canal along the Blackstone River.

But she said the town has become more aggressive in recent years about enforcing its storm water management rules and regulations, and said some measures may have prevented worse flooding.

For example, she said, the town mandates the use of dry wells for new construction, and enforces subdivision regulations that require that the 9,000 square feet the town requires for a buildable lot not include wetlands.

Richard Claytor Jr., an engineer with the Horsley Witten Group, outlined some low-impact development strategies.

Referring to the October storms, Mr. Claytor said that at a certain point, even the best storm water management plan will be overwhelmed.

“Watersheds that get over 5 inches of rain don’t care if it’s paved or if it’s a forest,” Mr. Claytor said. “With 10 to 12 inches of rain, you’re going to see some flooding.”

But smart, environmentally friendly residential development can help ease the strain on watersheds.

He said proper management of the water cycle should try to mimic a natural forest system, where soils, trees and plants absorb rainfall.

Impervious surfaces such as roofs and parking lots increase runoff into streams and rivers, and town planning boards should encourage development that uses alternative construction techniques and site designs to reduce the amount of impervious surface, he said.

He said solutions can be as simple as using rain barrels and permeable parking lot surfaces, building wide swales along a roadway, using “green” rooftops that have vegetation to absorb rainfall before it hits the ground as runoff, and installing rain gardens that use vegetated areas in parking lots to absorb runoff.

Mr. Claytor pointed to a mall parking lot design that used a turf-like surface for spaces that motorists typically don’t fill except on heavy shopping days such as the day after Thanksgiving. It was more aesthetically pleasing, and it reduced runoff in a rarely used portion of the lot, he said.

Andrea Cooper, smart growth coordinator in the office of coastal zone management at the state Executive Office of Environmental Affairs, urged towns to support local initiatives for open space residential design that maximizes open space by using creative design and incentives to developers, and Nathan Kelly of Horsley Witten, outlined how open space residential design is implemented with bylaws or ordinances.

Donna Williams, advocacy coordinator for the Massachusetts Audubon Society, said suburban sprawl development that does not incorporate ways to lessen storm water impact hampers the Blackstone River Coalition’s efforts to make the river fishable and swimmable by 2015. She said that as more communities along the Blackstone feel the effects of increased development, they should enact measures now that will prevent further degradation of the area’s rivers and streams.

Also at the conference yesterday, the Blackstone River Coalition announced that it has received a $15,000 grant from the John H. Chaffee Blackstone River Valley National Heritage Corridor Commission to hire a storm water management circuit rider to help communities.

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