The study area is located in the town of Yarmouth, Maine, which is located in Cumberland County, approximately 12 miles north of the state’s largest city, Portland. The Royal River originates in Sabbathday Lake, New Gloucester, ME and flows downstream for about 39 miles and empties into Casco Bay, Yarmouth, ME.
The Royal River is a freshwater system that transitions into an estuarine, tidally-influenced aquatic environment in Yarmouth. The head of tide is located approximately at the East Main St. /Route 88 Bridge in Yarmouth. The project location extends from the East Elm Street Dam, past the Bridge Street Dam to the Route 295 bridge.
The purpose of the study was to assess aquatic ecosystem restoration alternatives in the Royal River. This entails the assessment of the first two dams above the head of tide on the Royal River owned by the town of Yarmouth: the Bridge Street Dam and the East Elm Street Dam. Both dams have nonfunctioning/minimally functioning fishways. The project has the potential to restore access to about 71 miles of river habitat for federally listed fish species and non-listed anadromous fish species, providing the fish with upstream access to historic reproductive habitat for adults and nursery habitat for the development of eggs and juvenile life stages.
STUDY UPDATE (September 2025): The Royal River Aquatic Ecosystem Restoration study was successfully completed during the summer of 2025. The recommended plan was approved, and the final Detailed Project Report and environmental assessment were signed. The final report and appendices are located in the “Related Documents” section of this webpage
The Recommended Plan includes the following elements:
Removal of the Bridge Street Dam & Fish Ladder
- Removal of the entire fish ladder and
- Removal of the entire dam (275 ft)
Removal of the East Elm Street Dam & Fish Ladder
- Removal of the entire fish ladder
- 120 LF of dam on the right descending bank.
Construction of a Diversion at Middle Falls
- Placement of large boulders to increase flow to the side channel
- Chipping of rock ledges to optimize flow conditions and support fish passage
The next steps in the USACE Continuing Authority Program process are:
The project will move into the Design/Implementation (D/I) Phase. During this phase project designs will be completed, and construction of the project will take place. Prior to the D/I Phase, the town of Yarmouth will negotiate and sign a Project Partnership Agreement that will describe the cost share arrangement and operations and maintenance responsibilities.