Dam Removals Restore Fish Populations in Northeastern U.S.

Dam removals are bringing fish back across the Northeastern United States, one small barrier at a time. While large dam demolitions in the West attract more attention, numerous obsolete dams are being removed from northeastern streams and rivers, allowing herring and other fish to return in droves. Dams block river flow to create reservoirs for agriculture, recreation, household use, or industry, and can generate hydroelectric power, but aging structures are being dismantled nationwide to restore natural river flow.

Historical efforts to remove dams date back to 1859, when farmers in Billerica, Massachusetts, sought to destroy the Talbot Mills Dam on the Concord River, which powered a textile factory owned by Charles Talbot and was flooding their fields. They hired a surveyor, and Henry David Thoreau—who despised the dam for blocking spawning fish like American shad—took the job partly to oppose it, though his survey supported the farmers’ case, the state allowed the dam to remain.

Since 1912, over 2,300 dams have been removed from U.S. waterways, most in the last 25 years. In 2024, dam removals reconnected more than 2,500 miles of fragmented waterways, per American Rivers. Notable projects include the Blake Higgins Dam in Vermont, Edes Falls Dam in Maine, Kimball Brook Dam in New Hampshire, and 27 obsolete barriers in Pennsylvania, none taller than 20 feet. The Talbot Mills Dam, a three-century-old structure Thoreau opposed, remains a symbol of long-standing ecological impact.

Source: Hacker News · Summarized by HeadlinesBriefing