It’s not often (if ever) you hear of non-profit volunteers being asked to turn up in numbers to supply free labor to enhance a golf course, but that’s exactly what happened last week in Bristol.

This particular course, the new and vastly improved Bristol Golf Course, is still a season away from opening for golfers. But a key element of its not-so-secret secondary purpose — watershed filtration — was put into place last week.

Under the direction of Save the Bay’s Wenley Ferguson, 20 volunteers descended on the site beginning last Tuesday. In all, 1,600 shrubs, trees and herbaceous freshwater wetland plants were set in place in predetermined locations on the course.

“Save the Bay turned out their great network of volunteers,” said Bristol Town Planner Ed Tanner, who has been guiding this project since its inception several years ago. “We also had a big showing from Save Bristol Harbor, other Bristol residents, and Mt. Hope High School students — and I think every member of the conservation commission showed up, too.”

Volunteers served from two hours to two days, in weather that was favorable for working outside (though Mr. Tanner would like to see a little rain in the forecast now that this massive plant purchase is in the ground and looking to establish itself).

Planting locations were very specific, according to the landscape plan, to frame water features — so wherever there’s a stream, pond or wetland, there are new, native plants surrounding that feature. They will take some time to thicken and fill in the space they are meant to occupy, and when they do, they won’t serve just an aesthetic purpose but a functional one: helping to filter runoff from the industrial neighborhood around the course to keep it from entering the fragile Silver Creek watershed.

The team planted a range of species, including silky dogwoods, pussy willows, tulip trees and sweet gum.

The nuts-and-bolts of finalizing the project continues under Mr. Tanner’s leadership — he has just confirmed contractor U.S. Pitchcare as the lowest qualified bidder for phase 2 of the the project, which will start next week, visible on the north side of Broadcommon Road. Getting the course up and running, powering the irrigation pumps, and hiring a contractor to operate the course itself, under town authority, are all projects to be tackled in the near future.