N-1Work Order - Redacted
15 passages
DESCRIPTION: The purpose of this project is to mitigate the risk of fish entrainment at a tidally influenced pool downstream of the Tusket Powerhouse. By raising berms along the pool and altering the northern entrance, NS Power can better...
AI summary The project aims to mitigate fish entrainment at a tidally influenced pool downstream of the Tusket Powerhouse by modifying berms and water flow management. This ensures fish are not stranded during migration, with measures including controlled water inflow and adjusted pool drainage rates.
REDACTED CI C0064966 Page 2 of 6 REDACTED (CONFIDENTIAL INFORMATION REMOVED) As this tidally influenced pool is located on NS Power controlled lands adjacent to the Tusket powerhouse, thereby the Company has the responsibility to mitigate...
AI summary The document states that NS Power, which controls lands near the Tusket powerhouse, must implement a permanent solution to mitigate fish mortality in a tidally influenced pool located on those lands.
Why do this project now? This project must be completed before the 2026 gaspereau migration season starts and large numbers of fish migrate upstream. Once the fish begin to move upstream, there will be no opportunity to perform work in the...
AI summary NS Power must complete a project before the 2026 fish migration season to prevent avoidable fish mortality, comply with DFO directives, and reduce costs. The project includes tidal pool modifications and fish entrapment mitigation, with a Final Cost Date set for May 2027. DFO requires permanent solutions to address risks identified after a 2023 mortality event.
Why do this project this way? NS Power engaged Wood Canada through a competitive procurement process to perform an investigation of the site and provide design alternatives to mitigate the issue. The report completed by Wood Canada in 2023...
AI summary NS Power selected Option A-2, the least-cost design alternative from Wood Canada's 2023 report, to remediate a tidally influenced pool. The solution raises a berm, restricts fish access to a single entrance, and installs a timber crib and piping system to maintain water levels and ensure fish survival during low tides, following discussions with environmental services and the Mi'kmaq of Nova Scotia.
REDACTED CI C0064966 Page 4 of 6 Title: Tusket Tidal Pool Fish Passa cution Year: 2024 - 2026 age . Environmental Staff
AI summary The document discusses the Tusket Tidal Pool Fish Passa project, with a focus on environmental considerations and stakeholder involvement. It includes a table with an environmental staff section, indicating the project's timeline from 2024 to 2026.
begins to fall. The flow in and out of the tidal pond area during every tidal cycle attracts fish before they reach the powerhouse fishway. Once in the tidal pond, they have no access to the fishway. The environmental conditions that resul...
AI summary The document details fish mortality events at the Tusket Powerhouse, attributing them to shallow outlet channels trapping gaspereau during low tides, leading to oxygen depletion. While environmental conditions contributing to the 2023 fish kill require further study, the text emphasizes the need for remediation measures to prevent future mortalities during the 2024 migration season.
Options A-1 and A-2 The first options A-1 and A-2 were intended to provide designs that would minimize the ecological impact to the tidal pond and wetland, minimize permitting with just a minor watercourse alteration, no HADD, no or minima...
AI summary Options A-1 and A-2 aim to minimize ecological impact on tidal ponds and wetlands, reduce permitting requirements, and address archaeological concerns. Work must be completed by April 1, 2024, due to seasonal constraints, limited access, and the need for stabilization during tidal fluctuations.
Options A-3 to A-5 Options A-3 to A-5 require more disturbance of the wetland function and fish habitat and will take more, permitting time and also have a higher risk of siltation than Options A-1 and A-2.
AI summary Options A-3 to A-5 involve greater wetland and fish habitat disruption, longer permitting timelines, and higher siltation risks compared to Options A-1 and A-2, according to the analysis.
For all A options The idea of putting the outlet at the downstream end is to maintain the health of the tidal pond's water quality by having a flow through the full area during low tide. The watercourse flow only in Option A-1 was consider...
AI summary The text discusses options for maintaining tidal pond water quality by ensuring sufficient flow during low tide. Option A-1's flow is deemed insufficient in dry periods, while Options A-2 to A-5 propose adding 6 cfs of water to sustain a minimum 1ft depth at the outlet, facilitating fish egress.
3.12 Other Options Considered 1. The option of widening the inlet / outlet by removing a length of the berm (up to 40ft long) was considered. In this option, the fish would still enter the tidal pool area as the tide rose, and move back ou...
AI summary The text evaluates engineering options for modifying a tidal pool's inlet/outlet to improve fish passage during low tide. Options include widening the berm, constructing dual outlets, or maintaining a single upstream outlet. Each approach faces challenges related to silt management, water flow adequacy, fish behavior, and environmental impacts like oxygen depletion in stagnant water.
Description Pros Cons Potential Risks (Same as Option A-1, but Provide an Additional 6 cfs Inflow) in the exit for fish to leave during low tide. A single outlet will provide a single stronger current for the fish to follow when falling ba...
AI summary The document evaluates an option (A-2) that involves providing an additional 6 cfs inflow, which is compared to Option A-1. This option is discussed in terms of its benefits, such as lower risk of fish kill and improved water flow, as well as its potential risks, like minor spawning potential and attraction of fish to a dead-end flow.
The 6 cfs will require a pump or a siphon from the headpond. more fish. Less risk of the berm overtopping and bringing in Working with tidal influence water levels flood in the site. Description Pros Cons Potential Risks Option A-3: Block...
AI summary The text discusses engineering options for managing water levels in a tidal pond, focusing on fish passage and risk mitigation. It outlines a proposal involving a 6 cfs inflow and control structures to maintain water levels and reduce fish kill risks, while noting potential challenges such as limited access and seasonal constraints.
Description Pros Cons Potential Risks Option A-4: Block All Inflow to Tidal Pond to Unusual High Water Levels, Except Channel at Most Downstream End, Provide Additional Entrance to Existing Fishway to Provide 6 cfs Inflow (Same as Option A...
AI summary The document discusses Option A-4, which involves blocking all inflow to a tidal pond except for a channel at the most downstream end and providing additional entrance to an existing fishway to allow 6 cfs inflow. This option aims to improve fish passage and reduce the risk of fish kill, but it also carries potential risks such as increased predation and changes in water levels.
Description Pros Cons Potential Risks Cast-in-place concrete and earthworks will be required for the aboiteau (difficult during winter conditions). Poorer quality of work and increased risk of weather related construction delays. Cofferdam...
AI summary The document outlines potential construction challenges and risks related to building an aboiteau and associated earthworks, including weather-related delays, environmental impacts, and sediment runoff. It also mentions efforts to minimize the construction footprint and its effects on wetlands and wildlife.
5.1 Conclusions - 1) There are several options and different combinations of aspects of the options presented. The choice is basically between: - a) allowing the tidal pond area to continue as a wetland with the ecological benefits that su...
AI summary The document outlines options for managing a tidal pond to prevent fish mortality due to oxygen depletion, balancing ecological benefits with infrastructure constraints, and emphasizes the need for minimal environmental impact and timely construction.
N-2NSPI (NSEB) RIR 1 to 9 - Redacted
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NON-CONFIDENTIAL 1 assess and validate the existing conditions of the tidal pool as part of the design alternatives 2 evaluation, as referenced in NS Power's application. Studies also confirmed that the tidal 3 pool was wetland habitat and...
AI summary The text discusses the assessment and validation of the existing conditions of a tidal pool as part of design alternatives, noting that the area is wetland habitat and that archaeological monitoring is required for all alternatives considered.
CI C0064966 – Tusket Tidal Pool Fish Passage (NSEB M12746) NSPI Responses to Nova Scotia Energy Board Information Requests 1 Request IR-2: 2 3 Were there any fish mortality, fish distress, stranding, or similar incidents observed during 4...
AI summary The response to the Nova Scotia Energy Board's information request indicates that temporary mitigation measures during the 2024 and 2025 migration seasons were successful in preventing fish mortality and stranding. However, the use of diesel pumps and temporary cofferdams is noted as an unacceptable long-term solution due to environmental and operational risks.
NON-CONFIDENTIAL 1 The expected useful life of the piping system is between 15 and 30 years, as the pipe is 2 located in coastal conditions. No significant maintenance is anticipated before that point. 3 However, minor maintenance activiti...
AI summary The document discusses the expected useful life of a piping system in a coastal area, with minimal maintenance anticipated over 15-30 years. It also outlines the monitoring of fish in a tidally influenced pool and the reduction of manual intervention through a permanent valve system compared to temporary diesel pumps.
REDACTED 1 ISNetworld company grade. The commercial/technical criteria for the engineering design 6 species at risk, species of cultural significance at the project site, the construction schedule, 7 and the anticipated environmental permi...
AI summary The text discusses the environmental and engagement considerations for a tidal power project, including species at risk, cultural significance, and consultation with the Mi'kmaq of Nova Scotia. It emphasizes early engagement as part of project management and notes that no additional First Nations-related costs are expected over the project's life.