Lower Great Falls, also known as Somersworth Dam, is a captivating hydroelectric structure located in Rollinsford, New Hampshire.
Wind
Humidity
Completed in 1984, this concrete, gravity, and masonry dam stands at a height of 36 feet and spans 270 feet in length. With a storage capacity of 472 acre-feet and a maximum discharge of 8460 cubic feet per second, it plays a crucial role in managing the Salmon Falls River's flow and supporting the surrounding ecosystem.
Managed by the Federal Energy Regulatory Commission, Lower Great Falls is a state-regulated dam that undergoes regular inspections to ensure its structural integrity and operational efficiency. The dam features a controlled spillway with a width of 178 feet and is equipped with two slide (sluice gate) outlet gates. Its hazard potential is assessed as significant, indicating the importance of proactive risk management measures to mitigate potential dangers and ensure the safety of downstream communities.
With a risk assessment rating of very high, Lower Great Falls poses a critical focal point for water resource and climate enthusiasts. Its strategic location, impressive design, and vital role in hydroelectric power generation make it a significant landmark in the region. As efforts continue to monitor and maintain this essential infrastructure, it stands as a testament to human ingenuity in harnessing the power of water resources while respecting the natural environment.
Year Completed |
1984 |
Dam Length |
270 |
Dam Height |
36 |
River Or Stream |
Salmon Falls River |
Surface Area |
32 |
Drainage Area |
220 |
Nid Storage |
472 |
Outlet Gates |
Slide (sluice gate) - 2 |
Hazard Potential |
Significant |
Nid Height |
36 |