GORHAM – With water quality improved after a pulp mill’s closing, conservationists are now aiming at restoring once-abundant sea run fisheries in southern Maine’s Presumpscot River.

Several nonprofit groups and public agencies are working with Sappi Fine Paper on a plan to manage one of the nation’s oldest industrial rivers and possibly restoring the Presumpscot’s fisheries.

Sappi closed its pulp-making facility in Westbrook three years ago and the 26-mile-long river is cleaner than it’s been in a century.

The pending removal of the Smelt Hill dam in Falmouth will restore sea run fisheries on seven miles of the river, and the re-licensing of five other hydropower dams will likely lead to the installation of fish ladders on at least three dams.

The state also may require a fish ladder at the Cumberland Mills dam in Westbrook. The river has nine dams in all.

A coalition of groups called the Presumpscot River Steering Committee has been working on a plan to restore the fishery and will invite the public next fall to sessions aimed at refining its mission. Sea run species include American shad, river herring, alewives and Atlantic salmon.

Once the plan is completed in the fall, the steering committee will implement it, whether the state adopts the plan or not, said Catherine Groves, director of the Casco Bay Estuary Project.

“We don’t want to create a plan that sits on the shelves,” Groves told residents at a forum in Gorham on Tuesday. A second forum was to take place Thursday night at Falmouth Town Hall.

The Casco Bay Estuary Project brought the groups together after its board decided that improving the river’s water quality and habitat would bring significant benefits to the bay. The planning process is expected to cost about $100,000. It is being funded by a variety of federal and foundation sources.

In addition to Sappi, the key participants are the Portland Water District, the Friends of the Presumpscot River, the University of Southern Maine and the Maine Departments of Environmental Protection and Marine Resources.

Also included are the Natural Resources Council of Maine, the Coastal Conservation Association, the U.S. Environmental Protection Agency and the U.S. Fish and Wildlife Service.

A restoration could involve fish ladders, removal of dams or other approaches.