DAM REMOVAL AND ROCK RAMP FISH PASSAGE TO RESTORE SEDGEUNKEDUNK STREAM ALEWIFE AND ATLANTIC SALMON POPULATIONS

Sedgeunkedunk Stream, a tributary of the lower Penobscot River, drains a watershed of 54 square kilometers, including two mainstem lakes impounded by dams. These two dams, and a third dam that diverts water from a location near the stream mouth, were used to regulate and divert water for paper-making processes. These three dams and several historic mill dams contributed to the loss of alewife and Atlantic salmon populations from the Sedgeunkedunk watershed. Because these dams currently have no provisions for upstream fish passage, restoration of alewife and salmon is precluded. This restoration project addresses fish passage at the lower two dams. The City of Brewer will remove the Lower Dam as part of a mitigation agreement, thereby providing Atlantic salmon with access to suitable habitat upstream of the dam. The Town of Orrington and their partners have replaced the Meadow Dam (located five kilometers upstream at the outlet of Fields Pond) with a rock ramp fishway. Alternatives analyses demonstrated that a rock ramp fishway best met the goals of fish passage efficacy, wetlands protection, social acceptability, reasonable cost, and engineering feasibility. An intensive outreach program provided information to stakeholders and documented support from natural resource agencies, non-governmental organizations, local government, abutting landowners, recreational users and the general community. Stakeholder support was fostered by the efforts to include stakeholder issues in the alternatives analyses and implementation of the preferred alternative. The structure includes an innovative use of a liner to retain baseflows in the channel. Baseline biological sampling suggested by the Gulf of Maine Council's Barrier Removal Monitoring Guide is currently underway to assess changes in the aquatic community after restoration. Adult alewife will be stocked in 2009, and passively reintroduced from the Penobscot River over time. Restoring alewife runs to the watershed will reinforce the key trophic link of a littoral/pelagic zooplanktivore in the pond (currently represented by only one species, golden shiner), potentially allowing for increased diversity and resilience within the fish community.