Alewife basin on horizon
Fears of flooding can’t stop project
Opponents say it will cause more flooding in East Arlington and other vulnerable areas, but after multiple failed appeals and more than two years of delays, Cambridge is preparing to begin construction on a project that city officials say is critical to reducing sewage overflows into the Alewife Brook.
This fall, the city will start building a 3.4-acre storm-water detention basin just west of the MBTA’s Alewife Station that will catch runoff before it reaches the waterway.
The basin is part of a $117 million project funded by Cambridge and the Massachusetts Water Resources Authority to cut overflows into the brook from old sewer lines that combine storm runoff with domestic sewage. The effort to reduce the overflows must be completed by 2015 under the federal court order controlling the cleanup of Boston Harbor and streams flowing into it, including the Mystic and Charles rivers.
But opponents say the $14 million collection basin will cause more flooding around the Alewife Brook in areas such as East Arlington and North Cambridge, which are already plagued by repeated floods during heavy storms.
Stephen Kaiser, a Cambridge resident who took part in a series of unsuccessful appeals to stop the project, said even a five-year storm would overwhelm the basin, which is being built in the Alewife Reservation floodplain. He said Cambridge and the MWRA are just shifting flooding from around Fresh Pond to the Alewife.
“They have not proved that they are not increasing flooding,’’ said Kaiser.
But the state Department of Environmental Protection has ruled in favor of the basin’s construction, and an appeal to a Superior Court failed, said DEP spokesman Joe Ferson.
Ferson said that the project would significantly reduce the level of contaminants entering the brook, and noted that agency officials do not see any potential for causing additional flooding.
Michael Hornbeck, chief operating officer for the MWRA, said the basin would not ease or worsen flooding in the area, but it would perform a critical role in reducing pollution in the Alewife. The detention basin is projected to help cut the combined sewer overflows reaching the brook to about 7.3 million gallons a year by the end of 2015, he said, down from about 50 million gallons in 1998.
He said appeals have delayed the project by 27 months. “We’ve been anxious to move forward and get some improvements to the water quality in the Alewife Brook,’’ Hornbeck said.
Even if the basin does cause a “tiny bit of increased flooding,’’ Arlington Selectwoman Clarissa Rowe said, the point of the program is to reduce the combined sewer overflows into the brook.
“It’s worth it,’’ said Rowe, who also chairs the Arlington-Belmont-Cambridge Flooding Control Group. But she said Arlington would seek mitigation from Cambridge if the basin causes additional flooding.
Wendi Goldsmith, CEO of Salem-based Bioengineering Group Inc., which has worked with the state and Cambridge on the basin’s design, said large amounts of storm water will enter and slowly be absorbed by the basin before being released into the Little River, an Alewife Brook tributary. Much of the water that enters the basin will sink into the ground and migrate into the brook, she said, and the basin would not add in any way to flooding.
“This project contributes substantially to cleaning up the Alewife and the Charles River and, ultimately, Boston Harbor,’’ Goldsmith said.
While the basin has faced some opposition, it has long been supported by the Friends of the Alewife Reservation, said Ellen Mass, the group’s president.
Mass said the project will greatly improve water quality and help restore habitats for animals in the reservation, which include fox, coyote, deer, and otter.
“I think the right won out in this case,’’ she said.
The basin project is expected to take about two years, said Owen O’Riordan, Cambridge’s city engineer and assistant commissioner of engineering. The city expects to award the construction contract to Gioiso & Sons Inc., of Hyde Park, in the coming weeks, he said.
The project will also involve improvements to the Alewife Reservation’s recreational facilities, including the construction of an amphitheater, new signs, and boardwalks that can be used for educational programs about the watershed.
Once the basin is near completion, O’Riordan said, Cambridge can move forward with additional portions of the cleanup, including the separation of storm-water drains from sewage lines in the area around Concord and Huron avenues.
“Unless we can get this basin constructed, it puts every other project associated with sewer separation for the Alewife in jeopardy,’’ he said.
Brock Parker can be reached at brock.globe@gmail.com. 
