The Bassett Creek Watershed Management Commission is proceeding with a plan that would cut down nearly 1,000 trees in the western suburb of Plymouth to improve water quality in a nearby lake.

But hurdles still remain for the controversial project, and commissioners want to review it one more time next month.

The decision came Thursday on a 6-2 vote after more than two hours of discussion and pleas from residents to spare the woods and explore alternatives. Several commissioners said they don’t like the idea of removing that many trees, and they directed Plymouth project managers to inventory the forest and identify some trees that might be spared.

Commission Chairwoman Ginny Black said that the vote represents final approval of the $1 million project’s design but that the matter has to return to the commission next month with more information about the trees for a “final-final” approval.

The City Council would decide later this fall whether to award a contract for work to begin this winter. The commission will pay for the project with property taxes.

Homeowners said they were both frustrated and angry.

“This is so sad,” said JoAnn Atkins, who lives on Orleans Lane, which borders the woods. “We can just bulldoze hundred-year-old trees to build a ditch.” Atkins said she watches scarlet tanagers, pileated woodpeckers and owls in the forest, which also is habitat for foxes, deer and other wildlife. Others walk their dogs, jog or bike along the deteriorating asphalt trail through the woods.

The project would remove trees from the park because a stream that runs through it flushes too much phosphorus into Northwood Lake in New Hope, about a half-mile away. The unnamed stream flows about 50 days per year, during spring snowmelt and after heavy rains.

Derek Asche, Plymouth water resources manager, said the proposed plan would cut down trees along 30 feet on each side of the creek channel in the hilly terrain and also would build a holding pond to capture runoff and prevent erosion. He said that 785 trees are along the creek corridor, and 214 are in the proposed holding pond area.

Asche said the mature forest has shaded most ground cover, so too much bare soil on the forest floor and channel is eroding and carrying phosphorus downstream. The solution, he said, is to remove the trees, open up the creek bed to sunlight and plant its borders with wildflowers and shrubs.

Asche said the channel restoration and holding pond would reduce phosphorus into Northwood Lake by about 25 percent of what’s needed for the lake’s water quality to begin to improve. The project was proposed, he said, because the lake violates state water quality standards. The commission needs to be “proactive and stay ahead of the curve” in correcting such problems, he said.

Those opposed said alternatives need to be studied that would be more effective and less disruptive. They noted that trees provide many benefits that have not been factored into the decision, including better air quality, shade and energy conservation, reduced noise from nearby traffic, higher property values, wildlife habitat and recreation.

“Something’s backwards here,” said Erich Schroeder, another neighbor. “Northwood Lake is a neighborhood lake that I do want to take care of, but we need to keep this in perspective.”

Robert White, who lives along the lake, was the only citizen who spoke in favor of the project. White said the lake flunks water quality tests, and the phosphorus makes the water so green and thick with weeds that people can’t canoe on it by midsummer. “It’s in bad shape,” he said. “Something’s got to be done.”