How will removing the dam affect fish and wildlife?

Decades of data support that dams have negative impacts on river systems and that removing them most often improves fish and wildlife habitat quality. Dams increase water temperatures at least seasonally, alter natural water flows and sediment transport, inundate and transform upstream floodplains, and disrupt river continuity for migratory fish and other aquatic animals to pass upstream. Restoring the natural flow of a river promotes improved habitat quality and as a result, can increase the overall biodiversity of both the river and the surrounding wetlands and associated plants and animals linked to rivers.

In the case of the Pawcatuck River, removing the Potter Hill dam will improve fish passage for spring-migrating river herring, American shad and American eel, which are important species in the food chain for birds and other animals along the river and marine life in Rhode Island’s coastal waters and beyond. . Spotted and wood turtle populations, which are listed as endangered by the International Union for Conservation and Nature, will be able to move up and down the river freely.

Other dam removal projects such as the White Rock and Lower Shannock Falls Dams, have led to an increased passage by river herring and other fish species, as well as the return of osprey, great blue heron and other wildlife that rely on fish as a primary food source. Overall, the project partners seek to restore the natural free-flowing river conditions so the Pawcatuck River is more resilient to the effects of climate change.

Show All Answers

1. Why is the dam being removed?
2. Could the dam be repaired or partially removed?
3. Could a design similar to that of the Bradford fish passage project be used for the Potter Hill project?
4. What alternative designs have been considered and why was the proposed design selected?
5. What safety hazards are associated with the mill and dam structures?
6. How will removing the dam affect water levels in the river?
7. Will my household well be affected?
8. Many properties along the Pawcatuck River have private drinking water wells, especially on the Hopkinton side of the river. How many homeowners’ wells could be affected by the predicted drop
9. Will Westerly’s municipal water wells adjacent to the Pawcatuck River be affected?
10. How will removing the dam reduce flood risk to upstream and downstream properties? Will larger flood events (i.e., the 500-year recurrence flood) be worse upstream or downstream following dam removal?
11. Will removal of the dam cause increased flooding to downstream areas, including downtown Westerly?
12. How will removing the defunct dam and mill affect public access to and uses of the river?
13. How will removing the dam affect fish and wildlife?
14. How will removing the dam affect wetland systems upstream of the dam?
15. Is the proposed design accounting for climate change projections and worst-case future hydrologic scenarios?
16. Who is the project team?
17. What are the next steps?
18. Where can I get more information on the project?