Water main carries silt to lake

A burst water main near the dogleg where Doe Avenue becomes Warner Avenue, behind the Village of Winnipesaukee, sent a thick plume of silt into Lake Winnipesaukee yesterday morning.

While a crew from the Laconia Water Department worked to mend the break, water laden with silt flowed along a swale alongside the railroad track and into the lake at the Akwa Marina. Adam Mailloux of Atom Contracting, who is supervising construction at the Akwa Vista and Akwa Marina projects, said the incident merely highlighted a problem that recurs again and again with each rainfall. "The water travels three-quarters of a mile and it's still filled with sediment," he said. "It happens every time it rains."

Last year, following a citation by the New Hampshire Department of Environmental Services (DES) and a court order, the Village of Winnipesaukee constructed an extensive detention system. But formerly stormwater from the complex flowed into three pipes which emptied in the woods on the steep slopes above Centenary Avenue. The flow from largest pipe, located above the marina, gouged a gully fifteen deep in the hillside.

"Before they built the system," Mailloux said, "the run-off washed out the railroad bed, overflowed the swale, poured across the marina parking lot and took out the boat ramp."

The railroad tracks, he indicated, are filled with silt, which obscures the ballast and ties. The erosion also filled the marina with silt. Mailloux said that the previous owners of the marina, Charan Industries, took borings and found about five-and-half feet of silt had accumulated in the marina during the 1990s. Pointing to the slips nearest the shore, he said "these used to be six feet deep or more, but now they are maybe a foot-and-half or two feet deep. We can't rent them for anything other than a pontoon boat."

City Planning Director Shanna Saunders said yesterday that the detention system at the Village of Winnipesaukee was working as intended. However, she explained that the significant amount of silt that accumulated before the system was built is picked up during rain storms. Meanwhile, the municipal stormwater system cannot handle the volume of water, which has grown as the area has been developed. Saunders indicated that improvements to the municipal stormwater system would be required to overcome the problem.

Ironically, earlier this week Saunders toured the Akwa Vista site, where she'd halted work in February after determining that Atom Contracting's measures to control erosion failed to prevent excessive amounts of fill and waste from reaching the lake. Mailloux stressed that the water leaving the Akwa Vista site is now clear, free of sediment, while each rainfall carries more silt into the marina. "Are there two standards here?" he asked.