YARMOUTH — For as long as anyone living can remember, two dams have impounded portions of the Royal River as it flows through North Yarmouth and Yarmouth on its way to Casco Bay.

These dams have been in place since the late 18th century, when they or their predecessors were built to control flows and harness the river’s power for manufacturing purposes. Today the mills and others that once depended on the dams for energy are gone; the dams have become a relic of a bygone time.

Because they block the Royal River’s natural flow, the dams have also become an impediment to the migration of diadromous fish – alewives, shad, eels, perhaps Atlantic salmon – that once ascended the Royal from the sea. A fishway on one of the dams no longer works. The river above the upper dam, at Elm Street in Yarmouth, is now essentially a long, freshwater pond.

Both of the dams are now owned by the town of Yarmouth, which must decide what to do with them. The dams are old; if they remain in place, there will be capital costs for repairs and maintenance over time. If the town decides to remove them, there will be costs as well. Mother Nature may remove the dams regardless, with unplanned consequences.

A healthy discussion is getting under way. Defenders of the upstream “pond” and its recreational value have been heard from, as have the users of the harbor below the dams, where there’s understandable concern about increased siltation if the dams aren’t there. On the other side are advocates for a free-flowing river, migrating fish and other recreational and ecological benefits.

The Royal River Conservation Trust is a regional land trust headquartered in Yarmouth conserving land, trails and farms across the entire Royal River watershed. We are naturally concerned about the dams, their effects on the river and what should be done about them. We have conserved land above the dams, below the dams and between the dams in order to protect clean water, open space and habitat.

Until now, the Royal River Conservation Trust has refrained from taking a position in this debate, in the belief that it can best function as a clearinghouse for information about the river and the dams, helping everyone understand what’s at stake.

But with a decision drawing near – the Yarmouth Town Council is now more actively wrestling with the competing concerns and goals – it’s time for the trust to state its views publicly.

Our position: Move forward on the removal of the lower dam, at Bridge Street, while undertaking a more deliberate process for continued focus on the Elm Street dam. This process should include the convening of an advisory committee that includes all interested parties, particularly the three marinas and other waterfront users in Yarmouth harbor.

We support the dredging of Yarmouth harbor with no delay, and will support public funding for harbor dredging. Consultants have found that dam removal will not add toxins to the harbor; the Royal River Conservation Trust believes these findings should be rigorously confirmed.

The Royal River is already changing: Today, it’s cleaner than it has been in a century. It’s becoming more accessible as the Royal River Conservation Trust, various towns and organizations create opportunities to use it.

A dam in Pownal was recently removed by a private landowner with the conservation trust’s help. And the entire river is increasingly protected from unwelcome changes, thanks to the efforts of the state, other regional programs, local land trusts and the Royal River Conservation Trust.

As we debate the future of this magnificent resource, we need to consider its changing role in the communities through which the Royal River passes. Over the years, the river has been a transportation corridor, a significant fishery, a carrier of waste, a source of energy, a place for summer and winter recreation. Today, it no longer carries waste or makes power, but it’s still significant in myriad other ways.

The river is resilient and connects habitats, communities and recreational destinations. It’s time to restore it fully, beginning with the removal of the Bridge Street dam.

— Special to the Press Herald