CRANSTON, R.I. — Dams coming down are good for the environment, but what if those dams can be used for hydroelectric power?

Last Friday, a host of state officials and environmental leaders praised the removal of the Pawtuxet River Dam as vital for improving fish habitats and reducing floods waters.

Free-flowing water will allow American shad and river herring to reach spawning grounds up river. Flood crests should be lower and the water will be cleaner, cooler and more accessible for recreation.

“Our rivers are an unsung resource,” Sen. Sheldon Whitehouse, D-R.I., said.

Gov. Lincoln Chafee also spoke favorably of the need to remove dams for the benefit of the environment. Yet, he has also singled out hydroelectric power as one of the potential sources for lowering the cost of renewable energy in the state.

In August, Chafee toured a hydroelectric plant in Labrador, Canada, to show support for the expansion of an existing hydro plant. Rhode Island, he said, would draw from the souped-up power source to lower the cost of electricity in the state’s alternative energy portfolio. Chafee also seems to be showing support for building them in the state.

The Rhode Island Department of Environmental (DEM), the state Economic Development Corporation, and the Conservation Law Foundation are exploring hydro projects, some with municipalities, along the Blackstone River. So far, the organizations have identified several existing dams for potential hydroelectric installations, and permits have already been sought for studies at the Ashton and Albion dams in Lincoln and Cumberland, respectively.

Four dams along the lower Blackstone in Pawtucket and Central Falls also are being considered. The Elizabeth Webbing Dam, recently acquired by the DEM, has received federal permitting for a study to determine if the dam can generate power once again. It stopped generating energy in 2001.

Reaction to the initiative has been mixed. “It’s a very contentious subject,” said Peter Coffin of the Blackstone River Coalition. Fishermen are generally opposed to the idea of hydropower instillation, Coffin said, over potential harm to fish stock and impediments to upstream passage. His organization and other environmental groups, such as the Save The Bay, don’t want to see additional hurdles to the flow of the river. But in principal, at least, they are willing to see if the studies can find a balance between protecting the environment and building a power source.

“Save The Bay’s priority is on river restoration so we want to look carefully at these,” said John Torgan, the organization’s baykeeper.

Concerns also exist over water quality and the construction impacts on historical sites, which are being touted in the the bid to make the Blackstone Valley a national park.

Hydroelectricity accounts for less than 4 percent of power supplied to National Grid. Hydroelectric is considered green energy, and under the state’s new renewable energy laws, it has the potential to help it reach greenhouse gas reduction benchmarks. But the potential for harm to natural habitats does exist.

“It’s a dilemma for environmentalists,” Coffin said.

Thomas Ardito, a restoration program manager with the Narragansett Bay Estuary Program, has worked on licensing of hydroelectric dams as well as dam removal, including the Pawtuxet River Dam. The cost of customized equipment and height of the dam, preferably 20 feet or higher, often determine if a project is profitable.

“The reality is the economics on these small dams is not there at all,” Ardito said.

Rhode Island currently has a handful of smaller hydroelectric plants on former mill dams along the Blackstone and Pawtuxet rivers. The Thundermist Dam in Woonsocket generates 1.2 megawatts of power, or enough power for about 600 homes.

Ardito said the licensing process for installing power generation at an existing dam is much more rigourous than it was in the past, especially if the dam is in need of major repair.

Proponents of hydro maintain that adding hydro to some dams is economically viable and will help pay for long-term maintenance to the dams and adjoining ponds, while making sure fish can move upstream and downstream.

And environmental groups want to be sure the power projects won’t slow plans to build new fish ladders to create access for spawning at the Lonsdale Marsh in Central Falls.

Like most environmental officials, Ardito suggests taking a wait-and-see approach, but with an abundance of skepticism.

“Hydro has a place, but we need to look where it makes sense,” he said.

A tour of the Thundermist Hydroelectric Plant in Woonsocket is scheduled to be held Oct. 13 at 5 p.m.