Sebasticook River Fish Passage Projects

The Sebasticook River is the largest tributary (946-square mile drainage) to the Kennebec River, joining it in Waterville. Historically, this productive river has supported large runs of sea-run (anadromous) fish species: American shad, river herring (alewives and blueback herring), striped bass, rainbow smelt, Atlantic and shortnose sturgeon, Atlantic salmon and American eel all have utilized the numerous and varied types of riverine habitats in the Sebasticook. While sturgeon, striped bass and rainbow smelt likely used areas in the lower section of the river, American shad migrated as far upstream as the Town of Newport, and alewives into Wassookeag Lake and Great Moose Pond.

The survival of these highly migratory species is dependent upon access to healthy riverine habitat areas. Restoration of anadromous fish has multiple benefits to not only our natural ecosystems, but also for society: they serve as important forage for other fish and wildlife species in both inland and coastal ecosystems, and have been a resource of commercial and recreational fisheries in Maine for hundreds of years.

In 1998, the Edwards Dam on the Kennebec River in Augusta was removed, permitting anadromous fish to migrate an additional 17 miles upstream to the lower Sebasticook River. The owner of the first hydroelectric dam on the river, the Fort Halifax hydroelectric project, will provide permanent fish passage by May 2003 or partially breach/fully remove the dam in 2003. Based on a 1998 agreement, the owners of the next two upriver hydroelectric dams, the Benton Falls and Burnham dams, will provide fish passage pending the completion of passage at four non-hydro dams located further upstream on the Sebasticook. These non-hydro sites include the outlet dam on Pleasant Pond, where a fish ladder was installed in 1999; the outlet dam on Plymouth Pond located in the Town of Plymouth; and the Guilford and Sebasticook Lake outlet dams, both located in the Town of Newport.

Upstream and downstream fish passage at these last three dams would restore currently inaccessible, critical riverine habitat to native anadromous fish species. Passage would allow fish to migrate to these habitat areas, as well as provide a river corridor connecting upstream and downstream stretches in the Sebasticook River. In addition, it would trigger construction of fish passage at the two downstream hydroelectric dams, giving anadromous fish access to approximately 28 miles of additional habitat in the Sebasticook. With passage at these dams, the Sebasticook drainage would provide the largest spawning and nursery habitat area for alewives in the Kennebec River watershed -- approximately 9,300 acres initially, capable of producing approximately 2.2 million adult alewives. Full restoration of the Sebasticook River will eventually provide access to approximately 19,000 surface acres of lake habitat, resulting in the potential production of 4.5 million alewives. American shad spawning and nursery habitat area (~1,400 acres) could provide a production potential of about 133,000 adult shad in the Sebasticook River.

Newport Dams

The Town of Newport owns the Sebasticook Lake outlet and Guilford dams. The Sebasticook Lake dam was constructed in the mid-1980s to maintain lake levels and allow a fall drawdown to flush nutrients from the lake. Upstream passage at this site will take the form of a pool and chute fishway on the eastern side. Concerns with fishway design included accessibility by the public for viewing, potential impacts on downstream bridge abutments, and maintaining minimum flow requirements in the fishway itself. The Maine Department of Marine Resources’ (DMR) approach to this project, with the design expertise of the engineering firm URS Corporation, was to fit the fishway into the existing abutment structure. It will be located on the east bank, where the public will be able to view it. The pool and chute design will minimize the amount of water needed for effective upstream and downstream passage.

The Town of Newport also owns the 80+ years-old Guilford dam. The structure is in poor condition; Newport views it as a maintenance liability and has expressed a desire to remove it. However, the dam provides water for fire control for Guilford of Maine, a textile industry. Other issues facing removal are the Rt. 2 bridge immediately upstream of the site and a town waterline crossing: there was concern regarding the potential for hydraulic damage to the bridge piers (footings) and the waterline if the dam was removed. In 2001, DMR worked with the Town of Newport and Guilford of Maine to provide an alternative supply of water for fire control; an existing water main was extended to the Guilford of Maine property and can be tied into when renovations of existing on-site fire control equipment are completed. DMR hired URS Corporation to design and oversee the removal of the Guilford dam. Final designs for removal include a breach in the center of the dam and reduction of the height of the remaining structure to four feet. A partial breach was chosen because the remaining structure will reduce the risk of hydraulic damage to the Rt. 2 bridge piers and waterline.

In May 2001, the Guilford dam headpond was drawn down to facilitate surveys of the Rt. 2 bridge structure and the substrate beneath the piers. At that time, DMR and the Town of Newport decided it best to leave the gates at the dam open and the headpond drawn down to allow the area to re-vegetate over the course of the summer, thereby stabilizing the newly exposed soil. Stabilizing the riverbanks by natural means during the summer was desirable over artificial means at the time of dam removal, originally proposed for the fall of 2001.

All necessary permits have been secured for these projects and final designs have been completed. The Town of Newport solicited bids for the work in the fall of 2001. The engineering estimate for these two projects was $241,720. Newport, in consultation with DMR and Natural Resources Conservation Service (NRCS), decided to reject the bids. The headpond was not refilled, and as a result it became necessary to bury an exposed waterline just below the Center Street bridge. This work was part of the original project proposal and was funded by the NRCS and DMR. A request for bids for the Guilford dam breach was issued in May 2002 and a contract issued to Construction Divers, the low bidder, in June 2002 (the low bid was approximately the same as that received the previous fall). DMR reallocated state funds for the Sebasticook Lake fishway project so that the Guilford dam removal could proceed; work was initiated on July 15. The sponsors of the Guilford Dam Removal Project are DMR and the NRCS, with financial support from the National Fish & Wildlife Foundation's Maine Habitat Restoration Partnership grant administered by the US Fish & Wildlife Service (USFWS) Gulf of Maine Project, a USFWS Region V/ Wildlife Forever/ Fish America Foundation grant with financial support from D.M.F. Bait and Wal-Mart, and the Maine Corporate Wetlands Restoration Partnership. Guilford of Maine contributed to the cost of the new town water main.

Plymouth Pond Fishways

The Town of Plymouth owns the Plymouth Pond outlet dam. Upstream passage at this site will be accomplished through the use of two Alaskan steeppass fishways located on the north bank of Martin Stream. The Town has expressed concerns with the structural stability of the dam if it is modified with the installation of upstream fish passage and the amount of water required for its operation throughout the migration season. Other concerns include a series of ledges below the site that may hinder natural upstream migration. The outlet of Plymouth Pond is divided into two distinct channels by a ledge projecting from the middle portion of the dam in a westerly direction. A channel will be cut into this ledge to allow fish in the south channel to pass to the north and access the fishways. DMR met with the Town at a special town meeting and subsequently obtained a mutually satisfactory Lease Agreement that would allow DMR to construct, maintain, and operate a fishway at this dam. The Plymouth Pond fishways are scheduled for installation August 2002; the aluminum Alaskan steeppass sections and associated structures have been fabricated by Malatesta Machine & Welding. The contract for installation has been awarded to Building & Construction Services. Two fishways are being installed at this site: one in the dam and one at a small falls below the dam. It was discovered that a small section of the lower fishway was going to encroach on the property of a local telephone company, so a lease agreement had to be secured by DMR. By the time this was accomplished, nighttime temperatures were routinely below freezing, so installation was postponed until 2002. The sponsors for this project are DMR and the NRCS, with support from a National Fish & Wildlife Foundation Maine Habitat Restoration Partnership grant administered by the USFWS Gulf of Maine Project, a NOAA/Fish America Foundation grant, and Mid-Maine Communications.

Pleasant Lake Fishway, Stetson

In 1999, the Town of Stetson decided to rebuild the spillway of the Pleasant Lake outlet dam. DMR and the Town agreed it would be to everyone’s benefit if a fishway were installed during spillway reconstruction. The construction cost for the fishway (~$57,370) was completely funded by the NRCS ($39,734), USFWS ($15,000), and DMR ($2,635). In addition, DMR and Stetson worked with the NRCS, American Rivers, and the USFWS to remove the remnants of the Archer Sawmill Dam from Stetson Stream. This project included removal and disposal of up to five concrete piers; removal and disposal of up to 300 cubic yards of stone and dam debris; and removal and disposal of up to 500 cubic yards of sawdust, logs, and associated debris upstream of the dam. The cost of this project was completely funded by NRCS and the USFWS.

DEPT. OF MARINE RESOURCES

Sebasticook River Fish Passage Projects