OPINION | by Enrico Nardone |

Suffolk County recently opened the valves at Canaan Lake in Patchogue and drained the water out of the 26-acre impoundment of the Patchogue River.

When the mud dries, contractors will excavate out tons of sediment, re-close the dam and let the lake refill. The project – at a cost of $2.5 million – is aimed at addressing the invasive aquatic plants that overrun the lake each summer.

The new, deeper Canaan Lake won’t be as susceptible to plants taking over.

Having put up with a clogged and unsightly lake for many summers, the neighborhood will – understandably – be pleased by the results. Homeowners have the “water” back in their waterfront views. Anglers will have a much easier time accessing their favorite fishing spots.

It’s not the first such a project in the area. A few summers ago, the Town of Brookhaven spent nearly $4 million to address similar problems at Upper Lake on the Carmans River.

Later this summer, the town will spend even more to address invasive plants just downstream at Lower Lake.

While welcome by the immediate communities, these projects should give us pause. Many of the man-made impoundments on Long Island’s rivers and streams are facing similar problems, or soon will. All impoundments fill with sediment over time; when sunlight reaches the bottom, plants grow. Eventually the impoundments are choked completely and fail to provide any recreational or beneficial ecological services.

Dredging out sediment and invasive plants is one solution to the problem, but it’s expensive. And it’s only temporary; eventually the impoundments fill back in and plants return.

Over the long-term, dredging becomes an economically untenable strategy, especially since the dams (built decades, even centuries ago for purposes – grist mills, ice harvesting, cranberry production – they’re no longer serving) also impose significant ecological costs.

Dams break the connectivity of our flowing waterways. They prevent sediment from reaching our marshes (which is desperately needed in an era of rising seas).

And they block ecologically important migratory fish, such as River Herring, American Eel and Brook Trout, from moving freely and reaching the habitat they need to thrive.

Another solution?

Remove the dams and let the rivers and streams run freely. It’s a one-time expense that serves as a permanent fix. Natural stream channels will reform, tidal and freshwater meadows will take hold and usable parkland and private property will be expanded.

And, migratory fish populations will rebound, which will benefit our entire coastal ecosystem.

Dam removal is clearly not preferred or even possible in every situation; some lakes and ponds provide important recreational opportunities or are an integral part of their community.

On the other hand, we can’t afford – economically or ecologically – to keep every manmade lake and pond on Long Island.

Canaan Lake may have been an impoundment worth keeping, but in the long run, it has to be the exception and not the rule.

Dams are coming down across the country as communities increasingly recognize that it makes good economic and ecological sense. There has yet to be an intentional dam removal on Long Island. It’s time for us to let our rivers and streams run!

Enrico Nardone is the Executive Director of the Seatuck Environmenal Association. In March of 2017, Seatuck launched the “Long Island River Revival Project,” an island-wide effort to restore the ecological health of the region’s coastal rivers and streams.

More information can be found at www.seatuck.org.