BANGOR, ME, July 17, 2023 – An unexplained shut down of Brookfield Renewable Energy Partner’s McKay Hydro-electric Station below Ripogenus Dam occurred on July 7, 2023, that left the West Branch of the Penobscot River virtually dry for over 4 hours and resulted in devastating impacts to fish and aquatic communities, harmed the river system, and impacted boating and recreational activities.
According to Brookfield’s own data, McKay outflows normally range from 3000 to 1800 cubic feet per second (CFS). The Brookfield SafeWaters website posted an “outage” flow of 100 CFS at 7:00 p.m. on July 7 and it remained low at 11 p.m. Brookfield has offered no explanation for the extreme flow reduction. The resulting water flow drop was catastrophic for the recently hatched landlocked salmon in the river and shut down recreational activities for residents and visitors alike. Ripogenus Dam is located 30 miles west of Millinocket, Maine.
“Essentially, the entire West Branch 2023 salmon year class was eliminated,” said Ed Spear, retired fisheries biologist formerly employed by Great Northern Paper, an owner of the Ripogenus Dam before Brookfield. “The timing of this disastrous outage could not be worse as it occurred during the peak fish and aquatic growing season and a prime angling period and it occurred during daylight hours. Recently emerged alevin (larval salmon) are extremely vulnerable to rapid flow change and the initial dewatering and subsequent flooding of the riverbed. The Holbrook Spawning, Incubation, and Nursery Channel (FERC License Article 406) would have been completely dewatered during this event on July 7.”
The Ripogenus Dam (Project No. 2572) is currently facing FERC relicensing.
In a letter to the Federal Energy Regulatory Commission (FERC) which oversees such dams, in response to the Brookfield Ripogenus disaster, Spear wrote: “FERC has the ability to prevent and/or minimize future catastrophic flow interruptions caused by outages. Long-term and short-term mitigation measures are needed. Initially, FERC should order that a McKay Dam Tender position be created and staffed during the aquatic growing season, housing is readily available. Secondly, McKay Station emergency flow mechanism should be “reengineered” and maintained. Thirdly, during the ongoing licensing, the appropriate emergency outage flow should be determined as well as methods of delivering that flow to the river. Long term mitigation is needed to rebuild salmon stocks, notable the loss of 2023 hatchlings (alevin) and aquatic insects. This can be accomplished by requiring minimum flows of 2200 CFS accompanied by requiring the Licensee to follow a Ripogenus Impoundment storage curve that guarantees storage will be available to meet the year-long minimum flow goal.”
Many Problems at Ripogenus
The July 7 incident is the most recent in a series of events hurting the West Branch of the Penobscot River below Ripogenus Dam and Ripogenus-Chesuncook Lake, Maine’s third largest.
During the summers of 2020 and 2021, the lake was not filled and the drawdowns exceeded 20 feet making boat launches unusable, navigation of lake hazardous impossible, and shoreline travel treacherous with users having to carry boats and gear over hundreds of feet of exposed, unstable rock to the water. Loon nesting was severely impacted as well. Although these were dry years, McKay Station had generated heavily and not refilled the reservoir over the winters. Finally, the lake was refilled over the winter of 2021-2022 by drastically reducing power generation at McKay Station below the flow levels required to protect salmon spawning and incubation.
Bill Houston of the Chesuncook Caribou and Chesuncook Camp Associations stated: “We are very concerned the severe drawdowns of the lakes under Brookfield’s operation of Ripogenus Dam and McKay Station are having a negative impact on the fish, aquatic communities, wildlife and recreational use and enjoyment of one of Maine’s premier lakes.”
On April 20, 2022, seepage at the Ragged Lake Dam was discovered causing Brookfield to execute an emergency release of all the water in this reservoir that feeds Caribou Lake that connects to Ripogenus-Chesuncook Lake. The Ragged Lake bridge leading to the Greenville Road was washed out in the process requiring camp owners to take a much longer route from the Golden Road to a dewatered lake. The reservoir is being refilled in 2023.
Maine Trout Unlimited Calls for Action
Maine Chapter of Trout Unlimited requested that Brookfield conduct a study to determine the degree of stranding and mortality that was occurring during McKay Station generator trip events when flows fall quickly to 500 CFS. FERC approved the request and Brookfield conducted a drawdown mimicking a trip. This study was conducted on October 5, 2022. The results were shocking with numerous strandings of both fish and macroinvertebrates observed by the Brookfield contractor conducting the study as well as TU observers.
Stonefly nymphs and landlocked salmon young-of-the-year or fry were especially impacted with the young-of-the-year or fry being the most affected. Brookfield reported: “Stranded fish were observed throughout seven distinct reaches of the West Branch between McKay Station and the Nesowadnehunk Deadwater. Approximately 450 stranded fish were observed during the study, representing nine species: landlocked salmon, brook trout, slimy sculpin. Most stranded fish were young-of-year landlocked salmon (55 percent) followed by blacknose dace (31%) and banded killifish (5%). Of the stranded fish observed, approximately half were classified as mortalities.” This is even though the study was conducted under relatively benign weather conditions: water and air temperatures in the 60s.
The Trout Unlimited website has instructions on how to submit comments to FERC at http://tumaine.org/interacting-directly-ferc Reference project number P-2572.
The post NEWS: Brookfield Dam Empties West Branch of Penobscot River first appeared on On The Water.
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