Designers of the proposed 11,300-square-foot pharmacy worked with the Conservation Commission to develop a plan to capture rainwater in the store's parking lot. That plan includes a 20-foot-wide strip of elm trees and shrubs between the store and Providence Highway that will absorb water and return it to the soil.
But Planning Board members wanted to know last week whether the depressed patch of vegetation would be attractive and regularly cleaned and maintained.
"I want people to know that the reason we are concerned about this swamp is that we approved one before and could not get it cleaned up," said board member Robert Aldous.
Board member John Bethoney asked whether there would be standing water in the rain garden that would make people think it was a swamp.
"No. We are not creating a swamp," said Conservation Commissioner Jonathan Briggs. "If it performs like it should, you will not see standing water."
Briggs earlier outlined the benefits of designing buildings to minimize the amount of stormwater runoff and said the town's zoning bylaws often did not encourage good building practices.
Briggs said developments should minimize the amount of asphalt, or other impermeable surfaces covering the ground as much as possible. He said returning storm runoff to the ground not only saves water, but prevents streams and ponds from becoming contaminated with chemicals and debris washed off the street.
Stormwater from much of the Providence Highway area runs into Wigwam Pond.
Don Yonika, the head administrator of the Conservation Commission, said standing water would be quickly absorbed by the sandy soil mixture in the garden. He said a path had been built into the vegetation to make it easy to clean and, if a storm happened to dump more rain than could be immediately absorbed, an overflow system would release it into more conventional drainage.
"I have worked long and hard with the developer to make sure this will work," Yonika said. "This is the entrance to Dedham and it will look great."
After being reassured about the garden by the Conservation Commission, the Planning Board approved four waivers to town bylaws to allow the project's stormwater plan.
Planning Board Chairman Michael Podolski said a draft approval would be written and considered Wednesday. He said requirements for regularly scheduled cleaning of the rain garden could be included in any approval.
Podolski also said the board was considering prohibiting lefthand turns into the store from Elm Street and out of the store onto Elm Street during rush hours.
Daily News staff writer Patrick Anderson can be reached at 781-433-8336 or by e-mail at panderso@cnc.com.
