Follow a stream or river on Long Island and you will undoubtedly run across a dam or two. Beaver Lake is a result of a dam. Two streams run into Beaver Lake: Kaintuck Creek and Beaver Brook. Kaintuck has at least two dams on it of which I am aware. There are probably more. On Beaver Brook there is one at Frost Mill Road (Lower Francis Pond), the dam at Upper Francis Pond, and one more at the intersection of Oyster Bay Road and Beaver Brook. Among the tiny tributaries that feed into Beaver Brook within the Shu Swamp Nature Preserve there are three and possibly more that are on private property. So that’s a grand total of nine dams for a fairly small watershed! Now think about not just one watershed on Long Island, but the entire island, and even further, the entire US:
No wonder anadromous fish populations have collapsed.