The old swamp river is a cold-water fishery resource and anadromous fish run that historically supported a wild population of brook trout and currently provides critical spawning habitat for river…

The U.S. Fish and Wildlife Service Region 5 awarded $120,000 to the Town of Weymouth under the Coastal Program (CFDA 15.630) on June 18, 2025, for a dam removal project on the Old Swamp River in Massachusetts. The primary deliverable is the removal of a low-head dam constructed in the late 1980s that has severely impeded fish passage for river herring and other anadromous species. Upon completion, the dam removal will restore aquatic connectivity across approximately 20.34 miles of river habitat, including 4.65 miles on the mainstem of the Old Swamp River and 15.69 miles of tributary habitat, enabling river herring spawning migrations and restoring critical cold-water fishery resources historically supporting brook trout populations.

The project is expected to be completed by September 30, 2026, and represents a restoration initiative aligned with the Coastal Program's mission of providing technical and financial assistance for habitat protection and improvement projects benefiting federal trust species. The dam removal addresses both the historical operational failure of the associated sediment nutrient uptake pond system and the documented obstruction to fish passage documented by Weymouth herring wardens, thereby supporting ecosystem resilience and coastal fish habitat restoration goals.

The old swamp river is a cold-water fishery resource and anadromous fish run that historically supported a wild population of brook trout and currently provides critical spawning habitat for river herring. The old swamp river DAM is a low-head DAM originally constructed in the late 1980 s to direct water from old swamp river into a sediment nutrient uptake pond (snup) system. However, the system has never operated as designed, and does not provide the nutrient reduction benefits as intended. Instead, the weymouth herring wardens have documented that the DAM severely impedes fish passage for river herring. The DAM removal will open 4.65 miles on the mainstem of the old swamp river, and 15.69 miles including tributaries, so 20.34 miles total.