N-3NSPI (CA) RIR-1 to 18 - Redacted
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2.2 Proposed Refurbishment Activities The proposed maintenance activities are as follows: - installation of fish conveyance system near the entrance of the fish ladder; - lowering of Ruth Falls reservoir approximately 7‐15 feet; the actual...
AI summary The proposed refurbishment activities include the installation of fish conveyance systems, reservoir lowering, dewatering, concrete refacing, and the installation of new spillway and sluiceway components at Ruth Falls. These activities aim to improve fish passage, maintain proper water flow, and upgrade infrastructure.
NSPI Response: The water management plan will be developed in conjunction with the selected contractor upon award of the project. The construction sequencing plan will be the responsibility of the selected contractor. Due to liability issu...
AI summary NSPI outlines the process for managing water levels during construction, including lowering the reservoir through generation and controlled release, maintaining a minimum flow, and managing high inflows. Contractors are responsible for construction sequencing and cofferdam design, if needed. Environmental monitoring will be conducted during the drawdown.
EXECUTIVE SUMMARY Strum Consulting completed a rare species assessment, wetland delineation, and functional assessment at the Ruth Falls Dam on behalf of Nova Scotia Power Inc. in September 2017. The Ruth Falls Dam is located within the Ma...
AI summary Strum Consulting conducted a rare species assessment, wetland delineation, and functional assessment at the Ruth Falls Dam in September 2017 on behalf of Nova Scotia Power Inc. The study identified four wetlands and one rare bird species near the dam site.
1.0 INTRODUCTION Strum Consulting completed a rare species assessment, wetland delineation, and functional assessment study (the Study) on behalf of Nova Scotia Power Inc. (NSPI) in September 2017 at the Ruth Falls Dam Site. The Ruth Falls...
AI summary Strum Consulting conducted a rare species assessment, wetland delineation, and functional assessment study for Nova Scotia Power Inc. at the Ruth Falls Dam Site in September 2017. The study aimed to determine the biophysical characteristics of the area, including wetlands, watercourses, and species of conservation interest.
CI 50518 CA IR-5 Attachment 5 Page 19 of 160 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Rare Species Assessment, Wetland Delineation, and Functional Assessment September 29, 2017 Ruth Falls Dam Ms. Jenny LeBlanc Nova Scotia Power Inc. Pro...
AI summary This document discusses the Rare Species Assessment, Wetland Delineation, and Functional Assessment conducted on September 29, 2017, for the Ruth Falls Dam project by Nova Scotia Power Inc. It references appendices that provide delineation methodologies and a glossary of terms.
aea ( Spiraea tomentosa ). The species composition of these wetlands is characteristic of early successional wetlands. Shore marsh is the most abundant wetland type around the margin of Governor Lake. Tall shrub dominated shore swamp is fo...
AI summary The text describes the wetland ecosystems around Governor Lake reservoir, detailing the types of wetlands present, their characteristics, and the plant species that dominate them, including shore marsh, tall shrub dominated shore swamp, and low shrub dominated shore swamp.
Ruth Fall Flowage Reservoir Twenty-one wetlands were encountered and mapped around the Ruth Fall Flowage reservoir during the field survey (Figure 2A and 2B, Table 4). Six of these wetlands were described during the field survey. Most wetl...
AI summary During a field survey of the Ruth Fall Flowage Reservoir, twenty-one wetlands were identified and mapped. The wetlands were primarily shore bogs, with some larger complexes composed of coniferous treed shore bog and floating bog. Wetland types were categorized and further subdivided based on plant communities, with species composition data provided in Appendix E.
Table F1 Vascular Plant Cover of Dominant Species Found in the Six Wetlands Surveyed in the Ruth Falls Flowage Reservoir Wetland Common Name Scientific Name 3a ctb 3b ctb 4 sb 6a fb 6b fb 6c ctb 7 sb 11 sb 15a cts 15b ctb Balsam Fir Abies...
AI summary The table presents the vascular plant cover of dominant species found in six wetlands surveyed in the Ruth Falls Flowage Reservoir, detailing the percentage cover of each species across different wetland sites.
CI 50518 CA IR-5 Attachment 7 Page 13 of 103 REDACTED (CONFIDENTIAL INFORMATION REMOVED) NS Power will evaluate the use of silt curtains downstream during the construction of the downstream access path – silt curtains are applicable for st...
AI summary NS Power plans to use silt curtains during construction and will monitor sedimentation during re-watering. Contractors must submit erosion and sedimentation control plans, and NS Power may request conditions in approvals to ensure these measures are in place before construction begins.
3.1 Identification of Potential Monitoring Stations A total of seven monitoring stations will be established at several wetlands on the shores of Lake Vaughan, Gavels Lake, The Narrows, and Kings Lake, as identified from mapping from the N...
AI summary Seven monitoring stations will be established at wetlands near Lake Vaughan, Gavels Lake, The Narrows, and Kings Lake to monitor potential impacts from water level decreases. Eleven candidate sites are identified, with a mix of large and small wetlands included. Accessible sites will be prioritized for monitoring.
Station ID Location PID V1 Lake Vaughn (Southwest) 90315789; 90312893 V2 Lake Vaughn (East) 90331091; 90127622; 90313271 V4 Lake Vaughn (East) 90129909; 90129933; 90129941 Station ID Location PID V5 Lake Vaughn (East) 90127606; 90127622; 9...
AI summary The text presents a table with station IDs, locations, and PID numbers, followed by a section titled '3.2 Baseline Assessment'. The table lists various stations with their respective locations and PIDs, but no further details are provided in the excerpt.
Chapter 4 Monitoring Schedule During the preconstruction and construction periods, each monitoring station is proposed to be visited multiple times per year, as detailed below. Information on data to be gathered is also summarized. Note th...
AI summary The document outlines a monitoring schedule for wetland and hydrological conditions during the preconstruction and construction periods, including specific visits and data collection activities from August 2020 through summer/fall 2021.
3.2 SIGNIFICANT AREAS The GIS scan identified 2 biologically significant sites in the vicinity of the study area (Map 3 and attached file: \ sa\ .xls).
AI summary The GIS scan identified 2 biologically significant sites near the study area, as shown in Map 3 and the attached file *sa*.xls.
Phase 2 – Dam construction: - Lowering of Ruth Falls Headpond approximately 18 ft. - Dewatering of the Ruth Falls fishladder and canal during the construction activities. - Installation of temporary access for machinery on both the upstrea...
AI summary Phase 2 of the dam construction involves lowering the Ruth Falls Headpond, dewatering the fishladder, installing temporary access roads, and modifying the spillway and dam structure, including the installation of new rubber dam bladders and a free overflow spillway section.
CI 50518 CA IR-5 Attachment 11 Page 10 of 34 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Sluice Gate Installation Project and Environmental Description the Ruth Falls Headpond will be lowered appro...
AI summary The Ruth Falls Dam sluice gate installation project involves lowering the headpond by 18 ft to facilitate construction. This includes dewatering the canal, fishladder, and fish bypass, while maintaining a 35 cfs flow downstream. The drawdown will be managed using the centre vertical lift gate/deep sluice bay, and flow velocities will decrease as the headpond elevation lowers over a 4-day period.
Table 1: Estimated Flow Velocities Table Time (day) Beginning Elevation (ft) Middle Sluice Opening (ft) Discharge (cfs) Velocity through gate(fps) Downstream Velocity (fps) 0 109.2 1 211 21 2.4 0.5 108.8 1 209 21 2.4 1 108.0 1 204 20 2.4 1...
AI summary The table presents estimated flow velocities and discharge rates at different times during a drawdown process. The text discusses measures to control downstream flow to prevent scour and sedimentation, ensuring fish passage and temporary access once the headpond is lowered to 91ft.
CI 50518 CA IR-5 Attachment 11 Page 12 of 34 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Sluice Gate Installation Project and Environmental Description water levels remain below the spillway sectio...
AI summary The document discusses the construction of the sluice gate at the Ruth Falls Dam as part of the Sheet Harbour Hydro System project. It outlines the management of water levels, temporary access roads, and contingency planning for headpond elevation fluctuations. The use of vertical lift gates is highlighted as a key measure to ensure water passage during construction.
Table 4. Monitoring and Reporting Schedule for Wetland Monitoring Monitoring Event Wetland Monitoring WESP-AC Reporting Submission to NSECC Pre-construction Baseline ✓ ✓ Post-construction Year 1 ✓ ✓ Year 2 ✓ ✓ Year 3 ✓ ✓ Year 4 ✓ ✓ · · · ·...
AI summary Table 4 outlines the schedule for wetland monitoring and reporting, including pre-construction baseline assessments and post-construction monitoring over five years. Post-construction data will be compared to baseline data to evaluate vegetation, hydrology, and soils, with long-term impacts assessed after Year 5 and required consultation with NSECC.
CI 50518 CA IR-5 Attachment 14 Page 4 of 59 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Sluice Gate Installation Project and Environmental Description naturally from the sluice bay opening downstre...
AI summary The document discusses the Sheet Harbour Hydro System Ruth Falls Dam Sluice Gate Installation Project, focusing on cofferdam standards, water discharge capacity, construction scheduling, wetland monitoring methods, and the location of monitoring sites. NS Power provides references to sections in the document for detailed information.
Phase 2 – Dam construction: - Installation of downstream access road and bridge (to start prior to drawdown activities) - Lowering of Ruth Falls Headpond approximately 18 ft. - Dewatering of the Ruth Falls fishladder and canal during the c...
AI summary Phase 2 of the dam construction involves several key activities including the installation of access roads and bridges, lowering of the headpond, dewatering of fishladder areas, and the installation of new spillway sections and walkways. These activities are part of the overall dam construction process.
Table 3: Estimated Flow Velocities Table Time (day) Beginning Elevation (ft) Middle Sluice Opening (ft) Discharge (cfs) Velocity through gate(fps) Downstream Velocity (fps) 0 109.2 1 211 21 2.4 0.5 108.8 1 209 21 2.4 1 108.0 1 204 20 2.4 1...
AI summary Table 3 presents estimated flow velocities at different times during a drawdown process. The flow downstream is managed to prevent scour and sedimentation, with a 35 cfs maintenance flow and fish passage ensured. NS Power personnel will monitor water quality and conduct fish rescues during the drawdown.
Prior to the drawdown taking place, the temporary downstream access roads and bridge will be installed. The rockfill access road will be equipped with a bridge that will be located over the discharge channel -see Appendix C- Proposed Water...
AI summary Before the drawdown, temporary access roads and a bridge will be installed. The rockfill road will have a bridge over the discharge channel. Ice buildup is not expected due to constant water flow, and excavators will help break up any ice. If significant ice accumulates, the contractor will remove it.
CI 50518 CA IR-5 Attachment 14 Page 13 of 59 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Sluice Gate Installation Project and Environmental Description fluctuations in Ruth Falls Headpond throughou...
AI summary The document discusses the installation of a sluice gate at the Ruth Falls Dam as part of the Sheet Harbour Hydro System project. It outlines the plan to manage water flow during construction, including the use of the middle sluice bay and the construction sequence of the outer and center gates.
Baseline Monitoring Results Initial baseline monitoring was conducted on July 4-5, and September 6, 2022. All wetlands were accessed via boat over the Reservoir, and each wetland was accessed successfully, as locations provided by the JW (...
AI summary Baseline monitoring of wetlands was conducted in 2022 using WESP-AC protocols. Wetlands were accessed by boat, and monitoring wells and vegetation plots were installed. One wetland (WL17) was identified as an island within the reservoir. Results from the assessments are detailed in attachments and drawings.
CI 50518 CA IR-5 Attachment 19 Page 78 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Wetland and Wetland Fish Habitat Monitoring Plan, Ruth Falls Reservoir December 14, 2022 Ms. Kailey Osborne Nova Scotia Power Inc. Project # 21-7960...
AI summary The document discusses a wetland and wetland fish habitat monitoring plan for the Ruth Falls Reservoir, noting that water quality measurements were collected only at specific locations due to accessibility constraints. It highlights the presence of riparian buffers and forestry impacts around the reservoir.
CI 50518 CA IR-5 Attachment 19 Page 94 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED) 3 # Indicators Condition Choices Data Definitions/Explanations 29 100 to 1000 hectares. 1 30 >1000 hectares. [This is nearly always the answer in rel...
AI summary This section outlines criteria for measuring the distance from a site to large vegetated tracts, specifying conditions based on area and separation factors. The measurement method involves using Google Earth Pro and references the Fundy Model Forest Project's 375-ha criterion.
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 The area of wetlands and surface water ponded during most of the growing season that is both (1) in or adjacent to the AA and (2) within 1 km is: <0.01 hectare (about 10 m x 10 m). 0 0.01 - 0.1...
AI summary The text provides detailed instructions for measuring wetland and surface water areas adjacent to an area of assessment (AA), as well as the size of the largest nearby vegetated tract or corridor within 1 km. It also includes guidance on measuring distances to the nearest population and using tools like Google Earth Pro for accurate measurements.
CI 50518 CA IR-5 Attachment 19 Page 135 of 423 2 127 <10 m. 0 Nova Scotia Topo as the Basemap. Also enable the layer Forestry>WAM Predicted Flow. Then 128 10 - 50 m. 1 measure the inlet-outlet distance. [NR, OE, PR, SR, WS] 129 50 - 100 m....
AI summary The text provides instructions for measuring inlet-outlet distances and using a KMZ file in Google Earth for calculating growing degree days. It also includes guidance on assessing fish access or use for a specific area, referencing local biologists and reports.
Table 1B. Ruth Falls Reservoir - Wetland Monitoring Results Project # 21-7960 Wetland 5 Herbs Vaccinium oxycoccus Bog Cranberry 40 40 Iris versicolor Norther Blue Flag 5 5 Carex spp. Carex 30 Linnaea borealis Twinflower 10 25 Oclemena nemo...
AI summary Table 1B presents wetland monitoring results for the Ruth Falls Reservoir, including vegetation data such as species, common names, and percentages observed in baseline assessments from July and September 2022 across multiple plots.
CI 50518 CA IR-5 Attachment 19 Page 233 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED) - 1. Existing weir configurations and louvres outflow configurations were modelled and resulted in poor attraction flows (see Figure 3) - 2. The lou...
AI summary The text discusses various configurations of weirs and louvres outflow in an effort to improve fish passage. Multiple redesigns and tests were conducted, including changes to weir drops, flow distributions, and the addition of a rock diversion weir. Despite improvements, challenges with attraction flows and back currents persist, and field verification is expected post-construction.
3D CFD Modelling Once the details of the geometry were fully available and completely understood, a geometric model of the proposed structure (fully constructed), together with the fishway and downstream channel was assembled in Civil3D. T...
AI summary A 3D CFD model using OpenFoam was created to analyze fish passage quality around a proposed structure, including the fishway and downstream channel. The model was developed based on geometric data from Civil3D and considers various flow scenarios to assess fish movement and attraction flows throughout the year.
Modelling Results Each scenario (S1 to S7) contains 13 figures. Both plan views of the velocity magnitude, as well as cross-sections at regular intervals, with velocity vectors, are shown in panoramic views. - Figure 1 to Figure 3 : presen...
AI summary The document describes the modelling results for seven scenarios (S1 to S7), each containing 13 figures that depict plan views of velocity magnitude, cross-sections with velocity vectors, and panoramic views. The figures are categorized by focus areas such as water surface, fishway, and bottom velocities. The colour scale was adjusted based on a request to highlight velocities from 0 to 2m/s.
CI 50518 CA IR-5 Attachment 19 Page 330 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED) # Proposed Refurbishment / Change Explanation 4 Fishway entrance The notch in the entrance weir is located to the dam side of the fishway channel an...
AI summary The document outlines proposed changes to a dam's fishway and surrounding structures, including the relocation of louvres, removal of rock flow diversion, and flattening of riverbed bathymetry. CFD 3D modelling was conducted using OpenFoam software to assess the impact of these changes on fish passage.
2.3 Proposed Scenarios Based on 3D Model Results Using the OpenFOAM model results, Thaumas, evaluated the routes the fish are anticipated to select in the river below the dam based on their swimming abilities and endurance, required water...
AI summary The document outlines seven flow scenarios (Scenarios 1-7) evaluated using 3D model results from OpenFOAM to determine optimal fish passage conditions. Fish passage is primarily considered under Scenarios 1 and 2, which align with the required supplementary flows of 50 cfs under the current operating licence.
Proposed Scenario Based on the evaluation of the OpenFOAM model results, Scenario 1, with 6 cfs from the upper fishway and 29 cfs from the louvres (combining to provide 35cfs at the fishway entrance), and an additional 65cfs from the gates...
AI summary Scenario 1, involving specific flow rates from the fishway and gates, is recommended for upstream fish passage, particularly benefiting Eels. However, elvers and young eels may perform better in reality than modeled due to their movement patterns. An Eel pass is proposed for American Eels to improve passage past the dam.
CI 50518 CA IR-5 Attachment 19 Page 336 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED) all upstream migrating age classes of eels. The best location for an American Eel pass is depicted on Figure 1 in Appendix A. This scenario provides...
AI summary The text discusses the impact of supplemental flow releases on fish passage, particularly for American Eels and Salmon. It outlines the timing and volume of flows required to ensure adequate passage depths for Salmon while also accommodating other species.
Table 5: Proposed Scenario Based on Estimated Fish Passage of Selected Fish Species Scenario Fishway Louvre Gate Flow Supplementary Total Flow Flow (cfs) Outflow (cfs) (cfs) Flow (cfs) (≥10 (cfs) Scenario 1 with Eel Pass 6 29 65 Events) 50...
AI summary Table 5 presents a proposed scenario based on estimated fish passage for selected fish species, including flow rates for different components of the fishway system and total flow estimates under Scenario 1 with Eel Pass.
Closure This memo has been prepared for the sole benefit of NSP based on the information provided by Thaumas Environmental Consultants Ltd. The memo may not be relied upon by any other person or entity without the express written consent o...
AI summary This memo, prepared for NSP by Thaumas Environmental Consultants Ltd. and reviewed by CBCL, outlines findings and recommendations related to a 3D modelling and fish passage assessment project. The document is not to be relied upon by third parties without consent from CBCL or NSP.
CI 50518 CA IR-5 Attachment 19 Page 344 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED) 3 From June 15 to July 15 and September 26 to November 30 there are weekly supplemental flow events when the Ruth Falls headpond elevation is at 33....
AI summary The document describes supplemental flow events at Ruth Falls during specific periods to assist salmon migration. These events occur during significant inflow events and involve releasing water exceeding 50 cfs overnight. The flows are not modeled and fall between existing modeled flow ranges.
CI 50518 CA IR-5 Attachment 19 Page 345 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED) 4 cfs from the east gate closest to the fishway. The rock in front of the west gate will be removed and the bathymetry in front of the fishway has b...
AI summary The document discusses the configuration of fishway operations and gate flows, noting that the bathymetry in the area is not detailed, which may affect the accuracy of flow predictions. Fish passage migration routes are based on species-specific requirements for swimming abilities, velocity, and water depth.
Yellow stage American eel (600 mm) These eels will be too big for the eel pass, but they do have a strong swimming ability 0.87 m/sec for 60 sec and modeling shows they can pass though the fishway near the bottom surface or along the edge...
AI summary Yellow stage American eels (600 mm) are too large for the eel pass but can swim at 0.87 m/sec for 60 seconds. Modeling indicates they can navigate the fishway near the bottom or along the edge of notches, though their preference for short-distance travel may limit passage. They also use drain hole orifices at the bottom of baffles.
Yellow stage eels Figure 11: S1 routes for yellow stage eels shown on velocities 0.2 m from the bottom. The yellow stage eels will be oriented to the bottom. They can navigate comfortably in the blue colors and can't go more than a few met...
AI summary The passage of yellow stage eels through specific routes near a dam is analyzed, highlighting challenges with high velocities and color-coded zones. Larger eels (60 cm) have significantly higher passage rates compared to smaller ones (20 cm), and resting areas are crucial for their recovery. The orange route along the right bank margin is more navigable due to lower velocities.
Gaspereau Using the orange route gaspereau will have 12.5% passage overall. Over the first sill there is 5.5 m where the gaspereau must pass through velocities of up to 2.5 m/sec. 87.5% can pass over the first sill. Then they enter resting...
AI summary The document discusses the passage rates of gaspereau fish through different routes around sills. The orange route allows 12.5% passage, while the blue route offers 50% passage if resting areas are available but drops to 2.5% when the pool fills. Other routes also provide limited passage.
CI 50518 CA IR-5 Attachment 19 Page 383 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED) level and the drop is taken up on 7 weirs. The first weir is located approximately 35 ft downstream of the concrete fishway then the weirs are space...
AI summary The document describes the current structure and flow conditions of a fishway and associated weirs, including notch dimensions, weir spacing, and supplemental flow events. It also outlines the impact of the new dam on future fishway operations and flow management.
CI 50518 CA IR-5 Attachment 19 Page 385 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED) backwater on the notch slope, to one that is a combination of plunging and streaming flow. This improves passage for all species. It also introduces...
AI summary The text describes a modification to a notch slope that changes the flow from backwater to a combination of plunging and streaming, which improves passage for aquatic species and increases energy dissipation, reducing turbulence and velocity in pools.
Downstream passage The diadromous fish need to come back down past the dam at some point in their life cycle and resident species may choose to migrate down seeking suitable habitat. Some may come back down through the fishway or exit thro...
AI summary The document discusses the downstream passage of diadromous fish and resident species through a dam, highlighting the current design of louvers and the need for improvements, such as a solid wall for eels and a slated ramp to guide them to the surface outlet. It also mentions partial barrier stop log sections and the installation of a trap funnel to prevent fish from returning upstream.
CI 50518 CA IR-5 Attachment 19 Page 388 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED) orifices vs the overflow weirs in the concrete transition channel. This will ensure quick passage through a barrier free transition channel to the l...
AI summary The document discusses the design of a fish passage system, including orifices, overflow weirs, and a louver outflow pipe. The system is designed to ensure safe downstream passage for fish, adhering to USFW guidelines. The pipe discharges into a pool that dissipates energy from the head drop.
Summary This completes the full loop of fish passage from the upstream river passage routes, the fishway sections and the downstream louver system discharging between the two fishway sections to provide good attraction flow to the fishway...
AI summary The document describes a completed fish passage system that includes upstream river passage routes, fishway sections, and a downstream louver system. The system includes 11 new fishway weirs, an eel pass, and modifications to the power canal to remove barriers for downstream passage.
CI 50518 CA IR-5 Attachment 19 Page 393 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Major changes were undertaken during the rebuild of the louver bypass exit and monitoring shed operations based on Nova Scotia Power plans dated in...
AI summary The document describes modifications to the louver bypass exit and monitoring shed operations at a hydroelectric facility, including changes to the outlet pipe and canal reconstruction to improve fish migration and conveyance capacity.
CI 50518 CA IR-5 Attachment 19 Page 398 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Silver eels travel on the bottom of the watercourse with occasional movements up in the water column. They tend to spend considerable time migrating...
AI summary Silver eels migrate along the bottom of watercourses and are often insensitive to velocity changes until encountering obstructions. Deep bypasses are more effective for downstream migration than surface bypasses. Eels may move upward in the water column near dams and lakes, which can lead them to surface bypasses, spillways, or leakage from stoplog sections.
5.1 Lead the Eels to the Surface Outlet and Remove All Barriers Delaying Passage. The surface outlet is just 5 ft above the bottom but for eels traveling on the bottom, in fact usually in close contact with the bottom, this becomes a barri...
AI summary The document discusses the need to design a sloping ramp to help eels navigate past a 5 ft barrier at the surface outlet. The ramp is based on EPRI research and similar designs used elsewhere, ensuring ideal velocities for downstream passage and minimizing habitat loss.
5.2 Keep the Fish in the Bypass Channel and Improve Downstream Passage In the concrete channel, it is proposed that a trap funnel be installed at the most upstream stop log guide. This funnel would narrow the opening to 1.25ft and lead the...
AI summary The proposal involves installing a trap funnel in the concrete channel to prevent fish from returning upstream and modifying stop log sections to improve downstream passage for all species by creating larger orifices and eliminating resting pools.
4.2 Flow Conditions Hydraulic modeling was used to identify flow patterns, velocities, and depths, downstream of the dam that support fish passage (including eels) under various flow scenarios. The results of this flow modelling have been...
AI summary Hydraulic modeling was used to determine flow conditions downstream of a dam to support fish passage, particularly for eels. The model identified optimal locations for eel pass entrances and highlighted the use of low-velocity areas along the river banks and bottom for eel movement and resting.
4.3 Concept Design As previously noted, for upstream eel passage at the refurbished Ruth Falls dam, it is recommended to use a modern eel pass. The modern eel pass will consist of a covered linear metal, plastic or wooden channel lined wit...
AI summary The concept design for an upstream eel pass at the refurbished Ruth Falls dam includes a covered linear channel with climbing substrate and pumped water. Modifications include a re-designed baffled fishway, removal of a boulder, and flow distribution between gates to improve eel passage. The eel pass will follow specific engineering guidelines and use products from Aquatic Control and Barry and Escott.
4.4 Design Criteria To meet the USFW service recommendations, the final design will include: - Construction Materials: - o Ramps, pools, and supporting structural elements will be built of rust-resistant metal (typically aluminum) or UV-st...
AI summary The design criteria for the eel ramp include construction materials, cover specifications, entrance design, climbing substrate, and exit elevation to ensure functionality and minimize predation. The entrance must accommodate site-specific conditions and allow eels to enter at any depth.
CI 50518 CA IR-5 Attachment 21 Page 10 of 465 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project and Environmental Description - Dewatering of the Ruth Falls fishladder and canal and...
AI summary The text describes the Ruth Falls Dam Refurbishment Project, including activities such as dewatering, installation of new structures, fishway improvements, and demobilization. The project involves environmental considerations and infrastructure upgrades at the dam site.
CI 50518 CA IR-5 Attachment 21 Page 11 of 465 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project and Environmental Description - Construction activities associated with the sluiceway...
AI summary The Ruth Falls Dam Refurbishment Project involves construction activities starting in mid-July 2024, including dam refurbishment, fish passage improvements, and installation of new sluice gates. The project is expected to be completed by April 2025, with an approval expiry date requested for December 31, 2025.
CI 50518 CA IR-5 Attachment 21 Page 17 of 465 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project and Environmental Description important to note that the headpond would need to rise...
AI summary The document discusses the Ruth Falls Dam Refurbishment Project, focusing on the headpond elevation requirements for spillway operation and bridge removal. Table 2 provides details on discharge flows through various dam components.
CI 50518 CA IR-5 Attachment 21 Page 21 of 465 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project and Environmental Description removed. Once elevations hit 104 ft, the water would be...
AI summary The document discusses the Ruth Falls Dam Refurbishment Project, focusing on water management during construction. It outlines how the dam can handle high return period rain events, the measures to be taken during such events, and the design of access roads to avoid impacting discharge capacity.
Upstream Eel Passage An eel ramp is proposed to facilitate upstream eel passage as it was determined through the evaluation that a separate stand-alone structure was required for effective upstream eel passage, beyond the existing fishway....
AI summary A metal eel ramp is proposed to facilitate upstream eel passage, in addition to the existing fishway. The ramp will be placed outside the upper fishway and include pumped water and climbing substrate. Engineering designs for the ramp and other fish passage improvements are detailed in appendices.
CI 50518 CA IR-5 Attachment 21 Page 78 of 465 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Wetland and Wetland Fish Habitat Monitoring Plan, Ruth Falls Reservoir December 14, 2022 Ms. Kailey Osborne Nova Scotia Power Inc. Project # 21-7960...
AI summary The document outlines a wetland and wetland fish habitat monitoring plan for the Ruth Falls Reservoir, noting that water quality measurements were collected at LS locations and that significant forestry impacts exist around the reservoir, with riparian buffers generally separating the water's edge from forested areas.
CI 50518 CA IR-5 Attachment 21 Page 192 of 465 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Cover Page: Basic Description of Assessment WESP-AC version 2 Site Name: Ruth Falls Wetland 19 Investigator Name: Darcy Kavanagh & Angus Doane Date...
AI summary This document is a field assessment form for the Ruth Falls Wetland 19 conducted on July 5, 2022, by Darcy Kavanagh and Angus Doane. The assessment includes details about the site, investigator, and the use of the WESP-AC version 2 methodology. The form indicates that the entire assessment area was visited and that the investigators intentionally surveyed for rare plants and animals.
Netland 6 Wetland 6 - HYDROLOGICAL II NDICATORS Baseline (July 2022) Baseline (September 2022) Notes HYDROLOGICAL OBSERVATIONS (POST ALTE RATION) 111211020010/12 11 N.S. C. C. C. C. C. C. C. C. C. C. C. C. C. (301y 2022) Y/N Y/N Notes 1112...
AI summary The table provides data on hydrological indicators and vegetation composition for Wetland 6, including baseline measurements from July and September 2022, and notes on changes in surface water, saturation, drainage patterns, and species percentages.
Flow Assessment Spill flow data was available from 2015 to 2022. The full timeseries of the spill flow data is presented below in Figure 1: CI 50518 CA IR-5 Attachment 21 Page 231 of 465 Figure 1: Spill flow Timeseries from 2015 to 2022 at...
AI summary Spill flow data from 2015 to 2022 at Ruth Falls Dam shows infrequent spills, with increased frequency in 2021 and 2022 due to construction. Data from those years were excluded to reflect typical conditions. Flow duration curves were analyzed for seasonal variations, and current spill flows were found to provide suitable conditions for fish passage. Adjustments were made to improve fish passage conditions.
CI 50518 CA IR-5 Attachment 21 Page 233 of 465 REDACTED (CONFIDENTIAL INFORMATION REMOVED) - 1. Existing weir configurations and louvres outflow configurations were modelled and resulted in poor attraction flows (see Figure 3) - 2. The lou...
AI summary Various configurations of weirs and louvres were tested to improve fish passage and attraction flows. Initial models showed poor attraction flows, and several redesigns were attempted, including moving louvres, adjusting weir drops, and testing rock diversion. Despite improvements, strong currents from gate flows still disrupted attraction flows. An optimal flow distribution of 20 cfs, 40 cfs, and 5 cfs from the west, centre, and east gates was identified, but field verification may be necessary.
3D CFD Modelling Once the details of the geometry were fully available and completely understood, a geometric model of the proposed structure (fully constructed), together with the fishway and downstream channel was assembled in Civil3D. T...
AI summary A 3D CFD model using OpenFoam was created to analyze fish passage quality around a proposed structure, including the fishway and downstream channel. The model was developed based on geometric data from Civil3D and considers various flow scenarios to assess fish attraction and passage effectiveness.
Modelling Results Each scenario (S1 to S7) contains 13 figures. Both plan views of the velocity magnitude, as well as cross-sections at regular intervals, with velocity vectors, are shown in panoramic views. - Figure 1 to Figure 3 : presen...
AI summary The document describes the modelling results for scenarios S1 to S7, which include plan views of velocity magnitude, cross-sections with velocity vectors, and panoramic views of the study domain, fishway area, and river channel. The colour scale was adjusted based on Bob Rutherford's request to better visualize velocities from 0 to 2m/s.
3. Model Results of Scenario S3 with 925 cfs from the gates Figure S3-1: Plan view of the Water Surface Velocities Figure S3-2: Plan view of the Mid-Surface Velocities Figure S3-3: View of the Bottom Velocities Figure S3-4: Zoom-in view of...
AI summary This section presents the model results for Scenario S3 with 925 cfs from the gates, including detailed velocity vector diagrams across various areas of the channel, such as the fishway, downstream of the gates, and the middle and end of the channel.
6. Model Results of Scenario S6 with 4308 cfs from the gates Figure S6-1: Plan view of the Water Surface Velocities Figure S6-2: Plan view of the Mid-Surface Velocities Figure S6-3: View of the Bottom Velocities Figure S6-4: Zoom-in view o...
AI summary This section presents model results for Scenario S6, which involves a flow rate of 4308 cfs from the gates. It includes multiple figures illustrating velocity vectors at various points in the channel, such as the fishway area, downstream of the gates, and the middle and end of the channel, providing a detailed analysis of water surface and mid-surface velocities.
CI 50518 CA IR-5 Attachment 21 Page 336 of 465 REDACTED (CONFIDENTIAL INFORMATION REMOVED) all upstream migrating age classes of eels. The best location for an American Eel pass is depicted on Figure 1 in Appendix A. This scenario provides...
AI summary The text discusses the impact of supplemental flow releases on fish passage, particularly for American Eels and Salmon. It outlines the need for specific flow releases to ensure adequate passage depth for Salmon while also accommodating other species. The best location for an American Eel pass is referenced in Appendix A.
CI 50518 CA IR-5 Attachment 21 Page 344 of 465 REDACTED (CONFIDENTIAL INFORMATION REMOVED) 3 From June 15 to July 15 and September 26 to November 30 there are weekly supplemental flow events when the Ruth Falls headpond elevation is at 33....
AI summary The document describes supplemental flow events at Ruth Falls, scheduled during specific periods to complement significant inflow events, with the purpose of attracting salmon migration. These flows are not modeled and occur in addition to existing modeled flows.
Gaspereau Using the orange route gaspereau will have 12.5% passage overall. Over the first sill there is 5.5 m where the gaspereau must pass through velocities of up to 2.5 m/sec. 87.5% can pass over the first sill. Then they enter resting...
AI summary The document discusses the passage rates of gaspereau fish through different routes around sills. The orange route allows 12.5% passage, while the blue route offers 50% passage if resting areas are available but drops to 2.5% when the pool fills. Other routes also provide limited passage.
S3: 6 cfs from the fishway, 29 cfs from the louvre outfall, 925 cfs from the gates At these flows the resting areas in the middle of the channel are almost gone, but there are some eddies with resting velocities that form on the right bank...
AI summary At the specified flow rates, resting areas in the channel are reduced, and high velocities over the first sill may hinder passage for certain fish species, including gaspereau, trout, and eels, with limited passage for salmon.
CI 50518 CA IR-5 Attachment 21 Page 383 of 465 REDACTED (CONFIDENTIAL INFORMATION REMOVED) level and the drop is taken up on 7 weirs. The first weir is located approximately 35 ft downstream of the concrete fishway then the weirs are space...
AI summary The document describes the current fishway structure at Ruth Falls, including weir configuration, notch dimensions, and flow conditions. It also outlines supplemental flow events intended to assist salmon migration and notes that the new dam will eliminate leakage and additional flow in this section.
CI 50518 CA IR-5 Attachment 21 Page 385 of 465 REDACTED (CONFIDENTIAL INFORMATION REMOVED) backwater on the notch slope, to one that is a combination of plunging and streaming flow. This improves passage for all species. It also introduces...
AI summary The text discusses modifications to a notch slope that change the flow from backwater to a combination of plunging and streaming, improving passage for aquatic species and increasing energy dissipation, which reduces turbulence and velocity in pools, creating more resting areas.
Downstream passage The diadromous fish need to come back down past the dam at some point in their life cycle and resident species may choose to migrate down seeking suitable habitat. Some may come back down through the fishway or exit thro...
AI summary The document discusses the downstream passage of diadromous fish and resident species through a dam, highlighting the current design of louvers and the need for improvements, such as a solid wall for eels and a slated ramp to guide them to the surface outlet. It also mentions partial barrier stop log sections and the installation of a trap funnel to prevent fish from returning upstream.
CI 50518 CA IR-5 Attachment 21 Page 388 of 465 REDACTED (CONFIDENTIAL INFORMATION REMOVED) orifices vs the overflow weirs in the concrete transition channel. This will ensure quick passage through a barrier free transition channel to the l...
AI summary The document discusses the design of a fish passage system, including orifices, overflow weirs, and a louver outflow pipe. The system is designed to ensure safe downstream passage for fish, adhering to USFW guidelines, with specific details on the slope, drop, and pool depth.
Summary This completes the full loop of fish passage from the upstream river passage routes, the fishway sections and the downstream louver system discharging between the two fishway sections to provide good attraction flow to the fishway...
AI summary The document describes a completed fish passage system that includes upstream river passage routes, fishway sections, and a downstream louver system. The system includes 11 new fishway weirs, an eel pass, and modifications to the power canal to remove barriers for downstream passage.
CI 50518 CA IR-5 Attachment 21 Page 390 of 465 REDACTED (CONFIDENTIAL INFORMATION REMOVED) the louvers will greatly improve efficiency. The passage was further hindered by stoplog overflow weirs in the outlet transition channel combined wi...
AI summary The text discusses modifications to fish passage systems, including the installation of louvers, trap funnels, and orifice openings in stop logs to improve fish movement and efficiency. These changes aim to reduce barriers and assist fish in returning to the power canal.
CI 50518 CA IR-5 Attachment 21 Page 394 of 465 REDACTED (CONFIDENTIAL INFORMATION REMOVED) canal. The fish bypass is located at the vertex of the louver V array. As previously noted, the original bypass entrance design extended the full de...
AI summary The document describes the design and modifications of a fish bypass located at the vertex of a louver V array in a canal. The bypass was modified in 2006 to improve flow and include a concrete block and metal bypass, ending with a 32-inch diameter pipe that diverts flow to the river downstream of the fishway entrance.
CI 50518 CA IR-5 Attachment 21 Page 398 of 465 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Silver eels travel on the bottom of the watercourse with occasional movements up in the water column. They tend to spend considerable time migrating...
AI summary The text discusses the migration behavior of silver eels, noting that they travel near the bottom of watercourses and are often insensitive to velocity changes until encountering obstructions. It also highlights that deep bypasses are more effective for downstream migrant eels compared to surface bypasses.
5.1 Lead the Eels to the Surface Outlet and Remove All Barriers Delaying Passage. The surface outlet is just 5 ft above the bottom but for eels traveling on the bottom, in fact usually in close contact with the bottom, this becomes a barri...
AI summary The text discusses the design of a sloping ramp to help eels navigate past a 5 ft barrier at the surface outlet. The ramp, with a 15-degree slope and specific spacing between plates, is intended to guide eels along the bottom to the bypass opening, reducing delays and crowding during migration.
5.2 Keep the Fish in the Bypass Channel and Improve Downstream Passage In the concrete channel, it is proposed that a trap funnel be installed at the most upstream stop log guide. This funnel would narrow the opening to 1.25ft and lead the...
AI summary The proposal involves installing a trap funnel in the concrete channel to prevent fish from returning upstream and modifying stop log sections to improve downstream passage for all species by creating larger orifices and eliminating resting pools.
4.2 Flow Conditions Hydraulic modeling was used to identify flow patterns, velocities, and depths, downstream of the dam that support fish passage (including eels) under various flow scenarios. The results of this flow modelling have been...
AI summary Hydraulic modeling was used to determine flow patterns and velocities downstream of a dam to support fish passage, particularly for eels. The model identified optimal locations for eel pass entrances and highlighted resting areas along the river bottom and banks that eels use to navigate.
4.3 Concept Design As previously noted, for upstream eel passage at the refurbished Ruth Falls dam, it is recommended to use a modern eel pass. The modern eel pass will consist of a covered linear metal, plastic or wooden channel lined wit...
AI summary The document outlines the concept design for an upstream eel pass at the refurbished Ruth Falls dam. It recommends a modern eel pass with specific features such as a covered channel, climbing substrate, and pumped water. The design includes modifications to the fishway channel and gate flow distribution to facilitate eel passage.
4.4 Design Criteria To meet the USFW service recommendations, the final design will include: - Construction Materials: - o Ramps, pools, and supporting structural elements will be built of rust-resistant metal (typically aluminum) or UV-st...
AI summary The design criteria for the eel ramp include construction materials, cover specifications, entrance design, climbing substrate, and exit elevation to ensure functionality and minimize predation. The entrance must accommodate site-specific conditions and allow eels to enter at any depth.
CI 50518 CA IR-5 Attachment 21 Page 414 of 465 REDACTED (CONFIDENTIAL INFORMATION REMOVED) - o Location: the exit is situated at the head pond between the fishway exit and the utility shed away from turbine intakes, spill gates, and spillw...
AI summary The document outlines specifications for a fish passage ramp, including location, dimensions, slope, water depth, and resting sections. The design aims to ensure safe passage for eels while avoiding structures that may entrain them.
3.2 SIGNIFICANT AREAS The GIS scan identified no biologically significant sites in the vicinity of the study area (Map 3).
AI summary The GIS scan identified no biologically significant sites in the vicinity of the study area, as shown in Map 3.
N-6NSPI (NSUARB) RIR-1 to 13 - Redacted
106 passages
REFURBISHMENT OPTIONS Four different refurbishment options and one new dam option were reviewed with NSPI and are described below. The feasibility of each option was evaluated by modifying the hydraulic model used for the 2015 Sheet Harbou...
AI summary The document evaluates five refurbishment options and a new dam option for Ruth Falls Dam, analyzing their feasibility using hydraulic models and stability software. Options 1 and 3 could avoid raising the dam, while Option 2 may require raising it by 1 foot. The analysis also includes an opinion of probable construction costs and conceptual sketches for visual representation.
OPTION 3: REMOVE THE STOPLOGS AND INSTALL A LABYRINTH SPILLWAY AND REPLACE REMAINING STOPLOGS WITH SCREW STEM VERTICAL GATES Option 3 would replace stoplog bays and piers with a labyrinth spillway section, which would pass lower frequency...
AI summary Option 3 proposes removing stoplogs and installing a labyrinth spillway with vertical slide gates. This design allows more flow at lower headpond elevations, avoids raising the embankment, and provides freeboard during peak flood conditions. Stability analysis suggests minimal modifications may be needed, and rock anchors were considered for stabilization.
CI 50518 NSUARB IR-7 Attachment 1 Page 6 of 34 REDACTED (CONFIDENTIAL INFORMATION REMOVED) The length of the uncontrolled spillway section modelled was 200 feet, with a crest elevation equal to 109.2 feet, which would maintain the FSL. The...
AI summary The document discusses the design and stability considerations of a spillway section being converted from stoplog to rubber dam. It includes details on the dimensions of the spillway, hydraulic modeling results, and the need for stabilization methods such as rock anchors. The proposed design avoids the need to raise the embankment and ensures adequate freeboard during flood conditions.
Noise? п - 6. Tag line on load? ä п 3. Overhead power lines in area?
AI summary The text contains a table with questions related to noise, tag lines on load, and overhead power lines in an area, suggesting a discussion around infrastructure planning and grid-related concerns.
3.1 DRAWDOWN SCHEDULE NS Power intends to approach the drawdown of Ruth Falls Headpond the same way as all previous drawdowns conducted on its various hydro systems. Based on operational experience, the drawdown of Ruth Falls to elevation...
AI summary NS Power plans to draw down Ruth Falls Headpond slowly to minimize erosion and protect fish. The drawdown will initially use generating units and later stoplog bays, with additional time incorporated for controlled operation.
4.5.1 Drone Surveys NS Power will apply the following methodology to characterize the habitat in Ruth Falls Headpond during the drawdown. A baseline drone survey, completed within 1 week of the drawdown will be conducted using a drone‐ mou...
AI summary NS Power plans to use drone surveys to assess habitat changes in Ruth Falls Headpond during a drawdown. Baseline and monthly surveys will be conducted to monitor shoreline and aquatic vegetation changes, which will inform potential temporary HADD measures.
4.5.2.1 Sediment characterization The sediment classes used for the identification of sediment types are described in Table 6. Percent coverage of each type of substrate will be determined within each zone, delineated, and documented with...
AI summary The sediment characterization process involves identifying sediment types using classes described in Table 6. Percent coverage of each substrate type will be determined, delineated, and documented with digital imagery within each zone.
nt River and other sources will provide enough water for salmon and sea trout to spawn in Grant River. NS Power will lower the headpond to 91ft to create dry conditions while still ensuring enough water is available to maintain a 35 cfs fl...
AI summary NS Power plans to lower the headpond to 91ft to ensure sufficient water flow for salmon and sea trout spawning in the Grant River. Mitigation measures include offsetting habitat loss through actions described in section 16.
that would typically pass over top of the existing stoplog bays; • Potential changes to entrance conditions of the Ruth Falls fish ladder as a result of submerged discharge through the new gates (vs. surface overflow from stoplog bays). da...
AI summary The document discusses potential changes to the entrance conditions of the Ruth Falls fish ladder due to submerged discharge through new gates, as opposed to surface overflow from stoplog bays. It also mentions that dams are remotely operated and can be adjusted to manage water flow and mitigate impacts on fish passage.
3.1 DRAWDOWN SCHEUDLE NS Power intends to approach the drawdown of Ruth Falls Headpond the same way as all previous drawdowns conducted on its various hydro systems. Based on operational experience and employing a gradual drawdown to minim...
AI summary NS Power plans to gradually draw down the Ruth Falls Headpond to 91.0 ft over four days, using generating units and a vertical lift gate to control the process and minimize environmental impact. The drawdown will avoid exceeding 500 cfs flow and will be managed to prevent fish passage through the bypass once the canal becomes non-operational.
tion will be clean and fee of debris and all material will be removed in a responsible manner. Clean rock fill will be used, and geotextile / poly liner will be available to use should the need arise. During the drawdown, water will pass t...
AI summary The document discusses the process of removing debris and using clean rock fill during a drawdown operation, which will lower the headpond level from 109.25 ft to 91 ft over a 4-day period. Flow velocities are expected to decrease as the elevation lowers, as shown in Table 3.
4.6.2 Monitoring Transects Monitoring transects will also be completed once per month to supplement the drone surveys. One (1) monitoring transect will be selected on Ruth Falls Headpond. The position of the transect will not be located ra...
AI summary Monitoring transects will be conducted monthly at Ruth Falls Headpond to assess ecological changes, complementing drone surveys. Transects will be placed based on ecological value and include riparian and littoral zones. Data from transects and drone surveys will evaluate habitat impacts from drawdowns, with NS Power noting that short-term changes may not indicate permanent harm.
CI 50518 CA IR-5 Attachment 1 Page 108 of 132 REDACTED (CONFIDENTIAL INFORMATION REMOVED) would make for an unnatural baseline. Physical habitat monitoring will be able to show; improved migration pools, increased natural thalweg, establis...
AI summary The text discusses the development of a baseline monitoring plan for physical habitat improvements, including migration pools, riparian vegetation, and salmonid migration corridors, to be developed in collaboration with the NSSA's Fresh Water Biologist as part of a large-scale instream restoration project.
CI 50518 NSUARB IR-12 Attachment 10 Page 11 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) right end of the dam will also be replaced as part of the construction works. NS Power is anticipating an additional permanent instream footprin...
AI summary NS Power is replacing parts of a dam, including the right end and adding a permanent instream footprint. Changes will be made to improve the fishway's efficiency, such as adding weirs and adjusting weir and notch sizing. Construction materials and additional products will be submitted for approval based on health, safety, and environmental parameters.
3.2 Drawdown The reservoir will be temporarily drawn down approximately 18 feet, which serves as the primary method of isolating the existing dam structure for refurbishment activities. During the time the water is drawn down, the intent i...
AI summary The reservoir will be drawn down by approximately 18 feet to allow refurbishment of the dam structure. This will expose concrete sections for repair and ensure fish passage during construction. The drawdown will be managed using the Ruth Falls generating units and spillway stoplogs, with flow directed through normal channels. The process involves multiple stages and will temporarily halt operations at Ruth Falls until completion.
CI 50518 NSUARB IR-12 Attachment 10 Page 30 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) - Based on 2009 study, the louvre system and associated bypass is very effective for pelagic species such as alewife and trout. - The bypass may...
AI summary The document discusses the effectiveness of the louvre system and bypass for pelagic species like alewife and trout, based on a 2009 study. It notes that the bypass may have limited effectiveness for eels, as it was not possible to determine whether eels downstream of the dam used the bypass or the spillway.
CI 50518 NSUARB IR-12 Attachment 10 Page 42 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) potential to create access from the west side;however, it will be accessible once the downstream access roads and bridge are installed. Temporar...
AI summary The document discusses temporary access road construction for a project, noting that the roads will be built using clean rockfill and will be removed after completion. Fish monitoring and rescue will be conducted during the installation of access roads. The salmon trap is tied to the operation of the fish ladder.
1.0 STUDY OVERVIEW In 2009 and 2010, NSP completed tagging studies to assess the downstream movement of two migrating species at the Ruth Falls Dam: Atlantic salmon smolts and American eels. The intended outcome of the studies was to deter...
AI summary In 2009 and 2010, NSP conducted studies on fish passage efficiency at the Ruth Falls Dam, focusing on Atlantic salmon smolts and American eels. The studies assessed the effectiveness of the louvre diversion system and found that 57% of eels successfully passed downstream, with 70% evading the louvres and 40% surviving passage through the turbines.
REDACTED (CONFIDENTIAL INFORMATION REMOVED) CI 50518 NSUARB IR-12 Attachment 10 Page 113 of 591 Figure 1: Spill flow Timeseries from 2015 to 2022 at the Ruth Falls Dam As shown on the figure, spills are rather infrequent at this site. Spil...
AI summary The document discusses spill flow data from 2015 to 2022 at Ruth Falls Dam, noting increased spills in 2021 and 2022 due to construction. Data from these years were excluded for more representative analysis. Seasonal flow duration curves are presented, and modeling suggests that current leakage through the dam structure provides suitable conditions for fish passage, though improvements to weir configurations were made to enhance fish passage.
CI 50518 NSUARB IR-12 Attachment 10 Page 115 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) - 1. Existing weir configurations and louvres outflow configurations were modelled and resulted in poor attraction flows (see Figure 3) - 2. Th...
AI summary The document outlines various configurations and modifications to fish passage weirs and louvres outflow to improve attraction flows for fish. Despite several redesigns and adjustments, including the addition of a rock diversion weir and changes to weir orientation and notch placement, challenges remain with back currents disrupting attraction flows. Flow distribution from gates was optimized, but field verification may be needed post-construction.
3D CFD Modelling Once the details of the geometry were fully available and completely understood, a geometric model of the proposed structure (fully constructed), together with the fishway and downstream channel was assembled in Civil3D. T...
AI summary A 3D CFD model was created using OpenFoam to analyze fish passage quality around a proposed structure and fishway. The model was developed after the geometry was defined in Civil3D, and simulations were run for various flow scenarios to assess fish passage for different species throughout the year.
Modelling Results Each scenario (S1 to S7) contains 13 figures. Both plan views of the velocity magnitude, as well as cross-sections at regular intervals, with velocity vectors, are shown in panoramic views. - Figure 1 to Figure 3 : presen...
AI summary The document describes the visual representation of modelling results for scenarios S1 to S7. Each scenario includes 13 figures showing plan views of velocity magnitude, cross-sections with velocity vectors, and panoramic views of the study domain and fishway area. The colour scale has been adjusted to highlight velocities from 0 to 2m/s.
2.3 Proposed Scenarios Based on 3D Model Results Using the OpenFOAM model results, Thaumas, evaluated the routes the fish are anticipated to select in the river below the dam based on their swimming abilities and endurance, required water...
AI summary The document evaluates seven flow scenarios (1-7) based on 3D model results to determine optimal conditions for fish passage through a revised fishway. The scenarios consider the interaction between fishway attraction flow and gate flow, with fish passage primarily occurring under Scenarios 1 and 2. Supplementary flows of 50 cfs are required, and Scenario 1 would result in total flows of approximately 150 cfs.
CI 50518 NSUARB IR-12 Attachment 10 Page 218 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) all upstream migrating age classes of eels. The best location for an American Eel pass is depicted on Figure 1 in Appendix A. This scenario pro...
AI summary The text discusses the impact of supplemental flow releases on fish passage, particularly for American Eels and Salmon. It outlines the need for specific flow releases to ensure adequate passage depth for Salmon while accommodating other species. The best location for an American Eel pass is referenced in Appendix A.
Introduction Nova Scotia Power Inc has requested 3D hydraulic modeling to be completed at the Ruth Falls dam East River Sheet Harbour for the purpose of assessing post-refurbishment downstream river flow conditions. The main refurbishments...
AI summary Nova Scotia Power Inc requested 3D hydraulic modeling for the Ruth Falls dam to assess post-refurbishment downstream river flow conditions, particularly fish passage impacts. The modeling was completed by CBCL and provided in a January 27th, 2023 memo, including results for fish passage route analysis.
CI 50518 NSUARB IR-12 Attachment 10 Page 226 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) 3 From June 15 to July 15 and September 26 to November 30 there are weekly supplemental flow events when the Ruth Falls headpond elevation is a...
AI summary The document outlines supplemental flow events at Ruth Falls during specific periods to attract salmon migration. These events occur when there is significant rainfall and involve releasing water exceeding 50 cfs overnight. The flows are not modeled and fall between modeled minimum and maximum flows.
11 Table 2: Swimming Speeds by Time for 350 mm Trout in m/sec (Katopodis & Gervais, Ecohydraulic analysis of fish fatigue data, 2012; Di Rocco, 2020) Percent passage Sprint speed 5 seconds Burst speed 20 seconds Prolonged speed 200 seconds...
AI summary The table presents swimming speeds of 350 mm trout under various time intervals, highlighting differences in speed for different swimming durations. The text also mentions resident Brook trout, which are smaller and may need to pass upstream at dams for spawning or feeding, with the same criteria applied as for larger sea run Brook trout.
Yellow stage eels Figure 14: S2 routes for yellow stage eels on velocities 0.2 m from the bottom Some yellow stage eels will be able to navigate up to the fishway with 165 cfs of spill, but there are areas of fast velocity that will preven...
AI summary The text discusses the movement of yellow stage eels through fishways, noting that while some eels can navigate up with 165 cfs of spill, high velocities prevent most, especially smaller eels, from passing. Both routes allow 12.5% of 60 cm yellow stage eels to proceed.
CI 50518 NSUARB IR-12 Attachment 10 Page 267 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) backwater on the notch slope, to one that is a combination of plunging and streaming flow. This improves passage for all species. It also intro...
AI summary The text describes a modification to a notch slope that changes the flow from backwater to a combination of plunging and streaming, improving passage for aquatic species and increasing energy dissipation, which reduces turbulence and velocity in pools, creating more resting areas.
Downstream passage The diadromous fish need to come back down past the dam at some point in their life cycle and resident species may choose to migrate down seeking suitable habitat. Some may come back down through the fishway or exit thro...
AI summary The text discusses the downstream passage of diadromous and resident fish species through a dam, highlighting the need for improvements to the current louver system. It notes that eels require specific design modifications, such as a solid wall near the bottom and a slated ramp to guide them to the surface outlet. The text also mentions the use of trap funnels and stop log sections to manage fish movement.
CI 50518 NSUARB IR-12 Attachment 10 Page 272 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) the louvers will greatly improve efficiency. The passage was further hindered by stoplog overflow weirs in the outlet transition channel combin...
AI summary The passage discusses modifications to fish passage infrastructure, including the replacement of stoplog overflow weirs with a trap funnel and orifice openings to improve fish movement and efficiency. The changes aim to facilitate fish return to the power canal and reduce the length of the fishway.
CI 50518 NSUARB IR-12 Attachment 10 Page 276 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) canal. The fish bypass is located at the vertex of the louver V array. As previously noted, the original bypass entrance design extended the fu...
AI summary The document describes the design and modifications of a fish bypass system located at the vertex of the louver V array in a canal. The bypass entrance was modified in 2006 to include a concrete block and a metal bypass with a vertical opening that curves and widens into a concrete channel, ultimately directing flow to a pipe that discharges into the river downstream of the fishway entrance.
5. American Eel ( Anguilla rostrata ) Silver Stage Downstream Passage With the recent focus on the American eel, NSPI has been asked to review potential options for improving the effectiveness of the louvers to bypass downstream migrating...
AI summary NSPI has been asked to improve the effectiveness of louvers for downstream passage of silver stage American eels. Studies show that while louvers provide suitable attraction flow, the bypass channel design allows eels to move back upstream, potentially reducing the success of downstream migration.
CI 50518 NSUARB IR-12 Attachment 10 Page 280 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Silver eels travel on the bottom of the watercourse with occasional movements up in the water column. They tend to spend considerable time migr...
AI summary Silver eels migrate near the bottom of watercourses and are insensitive to velocity changes until encountering obstructions. Deep bypasses are more effective for downstream migration than surface bypasses. Eels may move upward in water columns near dams and lakes, which can lead them to surface bypasses, spillways, or leakage points.
CI 50518 NSUARB IR-12 Attachment 10 Page 281 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) the Alden modeling (Allen et al 2005) that indicates the velocities are good for guiding the eels to the bypass both at the bottom and along th...
AI summary The document discusses the effectiveness of louvers in guiding eels to a bypass, noting that large numbers of eels have been observed at the bypass entrance. It also highlights the need for checking and repairing gaps in the louvers and suggests design changes to improve passage efficiency through the existing surface outlet.
5.1 Lead the Eels to the Surface Outlet and Remove All Barriers Delaying Passage. The surface outlet is just 5 ft above the bottom but for eels traveling on the bottom, in fact usually in close contact with the bottom, this becomes a barri...
AI summary The text discusses the design of a sloping ramp to help eels navigate a 5 ft barrier at the surface outlet. The ramp is intended to guide eels along the bottom to the bypass, reducing delays and crowding. The design is based on research by EPRI and has been used in similar projects.
5.3 The Transition from the Bypass Channel to the Pipe The next problem location is where the cement channel connects to the pipe to the river. This is a very turbulent pool as the flow drops over the stop logs down to a bottom the outlet...
AI summary The document discusses the transition from the bypass channel to the pipe, highlighting concerns about turbulence and potential harm to fish due to the flow dynamics at the connection point.
6. Conclusions - 1) The installation of a ramp and bottom walls along the louver will greatly improve entrance conditions for eel and other benthic species traveling along the bottom. This option would provide passage for yellow stage eels...
AI summary The document discusses improvements to fish passage through the installation of a ramp and bottom walls along the louver, which would enhance downstream migration for eels and other species. It also addresses the need to prevent upstream movement of fish by using trap funnels and bottom orifices in stop logs, while ensuring flow velocities remain within safe limits for fish passage.
3. Modern Eel Passes Generally, technical upstream fishways, such as fish ladders and fish lifts, are ineffective at passing juvenile eels. Therefore, specialized eel pass structures are required to provide a path for them over the dam (Vo...
AI summary Modern eel passes are specialized structures designed to help juvenile eels navigate dams. They consist of linear channels with climbing substrate and pumped water flow, and in some cases, attraction water. These structures are necessary because traditional fishways are ineffective for juvenile eels.
3.5.1 Study Plan The duration of the drawdown is scheduled to take 8 days starting no earlier than July 10.The planned late start date of the drawdown will provide time for juvenile fish to grow and increase their chance of survival during...
AI summary The study plan outlines an 8-day fish monitoring period during a drawdown, starting no earlier than July 10, with monitoring conducted before, during, and after the drawdown. An adaptive sampling approach will be used based on equipment retrieval and fish catch rates, using various gear types to capture different species and life stages.
3.6.1 Drone Surveys NS Power will apply the following methodology to characterize the habitat in Ruth Falls Headpond during the drawdown. A baseline drone survey, completed within 1 week of the drawdown will be conducted using a dronemount...
AI summary NS Power plans to use drone surveys and GIS to monitor habitat changes in Ruth Falls Headpond during and after a drawdown. Baseline surveys will be conducted early in the drawdown process, with follow-up surveys to track shoreline evolution and habitat suitability for fish.
Potential effects on Localized: Ruth Falls Low High Improve No residual HADD anticipated upstream fish passage due Headpond, East River ments to change from stoplog Sheet Harbour to controlled to vertical lift louvre gate sluiceway and sys...
AI summary The text discusses potential effects on upstream fish passage due to changes in sluiceway and spillway systems, including modifications from stoplog controlled to vertical lift gate and rubber dam spillway. It also mentions localized areas such as Ruth Falls and Sheet Harbour.
CI 50518 NSUARB IR-12 Attachment 10 Page 373 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) A B C D E 243 2-5%. 1 large (longer than ~1 km), this may be estimated using Google Earth to determine the minimum and 244 6-10%. 0 maximum ele...
AI summary The text outlines a methodology for evaluating vegetated buffers around a zone extending 30 m from the edge of an area of assessment (AA), focusing on the percentage of perennial vegetation cover and the type of upland land cover adjacent to wetlands.
CI 50518 NSUARB IR-12 Attachment 10 Page 385 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) A B C D E 48 F8 Downed Wood The number of downed wood pieces longer than 2 m and with diameter >10 cm, and not persistently submerged, is: Excl...
AI summary The document provides a table with criteria for assessing downed wood in a specific area, including measurements and exclusions. It outlines thresholds for the number of downed wood pieces and their relevance to vegetated cover and habitat assessment.
CI 50518 NSUARB IR-12 Attachment 10 Page 405 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) 2 90 river flooding unrelated to tidal storm surges. A B C D E OF18 Relative Elevation in In Google Earth, enable the Terrain layer (lower left...
AI summary This section discusses the calculation of relative elevation in a watershed using Google Earth's Terrain layer and a KMZ file. It provides instructions for determining an area's elevation and comparing it to the watershed's maximum and minimum elevation.
CI 50518 NSUARB IR-12 Attachment 10 Page 413 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) A B C D E Potential For an average person, walking is physically possible in (not just near) >5% of the AA during most of the growing season, e...
AI summary The text discusses potential accessibility and visitation metrics for an Area of Concern (AA), focusing on factors such as walking accessibility, infrastructure proximity, and human visitation rates. It outlines criteria for determining the percentage of the AA that is unvisited and includes considerations for inhabited buildings and trail visibility.
CI 50518 NSUARB IR-12 Attachment 10 Page 425 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) 3 # Indicators Condition Choices Data Definitions/Explanations OF18 Relative Elevation in In Google Earth, enable the Terrain layer (lower left...
AI summary The text outlines indicators related to elevation and water quality sensitivity for a specific area. It provides instructions for determining relative elevation using Google Earth and defines criteria for identifying water quality sensitive areas based on protected water supply classifications and sampling data.
CI 50518 NSUARB IR-12 Attachment 10 Page 433 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) A B C D E F17 Forb Cover Within parts of the AA having herbaceous cover (excluding SAV), the areal cover of forbs reaches an annual maximum of:...
AI summary The text discusses the classification and measurement of herbaceous plant cover, specifically forbs and sedges, with criteria for their areal coverage in different percentages. It also identifies the dominant herbaceous species and includes notes on what types of plants are excluded or included in the assessment.
CI 50518 NSUARB IR-12 Attachment 10 Page 453 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) A B C D E 243 2-5%. 0 large (longer than ~1 km), this may be estimated using Google Earth to determine the minimum and 244 6-10%. 0 maximum ele...
AI summary The text outlines procedures for evaluating the vegetated buffer and land cover surrounding a wetland area (AA). It provides guidelines for estimating elevation changes and determining the percentage of perennial vegetation cover within a 30-meter buffer zone.
2.2.3 Substrate and Cover A 0.5 m x 0.5 m quadrat was employed to determine substrate composition. The quadrat was divided into 20 squares with equal area such that each square represented 5% of the total quadrat area. Substrate compositio...
AI summary This section describes the methodology used to assess substrate composition and cover in a study area. A 0.5 m x 0.5 m quadrat was used, divided into 20 equal squares to assess substrate size classes, including fines, gravel, cobble, boulder, and bedrock. Embeddedness and unembedded cover were also evaluated, along with juvenile and adult fish concealment.
CI 50518 NSUARB IR-12 Attachment 10 Page 547 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Figure 4 A - H Thermal (left) and visible (right) imagery of the site of a proposed restoration in West River Sheet Harbour. Images are ordered...
AI summary The document includes a figure showing thermal and visible imagery of a proposed restoration site in West River Sheet Harbour, with images ordered from upstream to downstream.
Alewife Previous monitoring studies and observations from NSPI personnel suggest that the East River alewife run consists likely of a few thousand fish; however, this is only a qualitative statement. NS Power will work with Innovasea to in...
AI summary NSPI plans to install AI-powered cameras in the fish ladder of the East River to monitor alewife migration, with daily checks and visual observations to assess the impact of dam refurbishments. Similar programs have been used successfully at other sites.
CI 50518 NSUARB IR-12 Attachment 10 Page 587 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) wet weight, following a calibration made on the measure of a representative number of individual fish (likely 50- 100; elver size is usually si...
AI summary The document discusses the methods used to monitor eel migration, including daily counts from April to June and the use of fyke nets to assess the efficiency of new elver ladder traps. It highlights the behavior of eels and the need for time to establish chemical signatures for optimal trap efficiency.
Study design Downstream monitoring of migrating alewife and American eels will be conducted using High Resolution (HR) acoustic tags and hydrophones. Hydrophones are proposed to be deployed in the headpond (4), the entrance to the intake c...
AI summary The study design outlines the use of high-resolution acoustic tags and hydrophones to monitor migrating alewife and American eels. Hydrophones will be placed in several locations within the watershed, including the headpond and intake canal, to track the movement of tagged fish and determine their migration paths.
CI 50518 NSUARB IR-12 Attachment 10 Page 589 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Figure 2 Proposed hydrophone deployment locations downstream of louvres and downstream of tailrace confluence Similar to the studies conducted...
AI summary NSPI proposed using a bypass facility to catch and hold sample fish, similar to studies conducted in 2009 and 2010. The bypass flow will be redirected through a holding facility, and captured fish will be transferred to a holding cage.
2.4 Data analysis and reporting Depending on the environmental conditions, hydrophones will be recovered at least four weeks after the final fish release to ensure that all tagged fish have completed their downstream movement past the Ruth...
AI summary Hydrophones will be recovered four weeks after the final fish release to analyze acoustic data for tagged fish detections, with recovery likely around the end of October depending on the American eel migration timing.
CI 50518 NSUIARB IR-12 Attachment 12 Page 5 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) migrating around the dam to complete their lifecycle. The addition of an upstream eel pass will also be installed to support specific upstream p...
AI summary The project involves modifying the Ruth Falls dam to improve fish passage and install a new rubber dam system. Construction will begin in July 2024 and include the installation of upstream and downstream access roads, dewatering, and the construction of a new control building. The project will not alter discharge flows after completion.
CI 50518 NSUIARB IR-12 Attachment 12 Page 7 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Table 1 displays the decrease in flow velocities as the headpond elevation lowers over the course of the 8-day drawdown period.
AI summary Table 1 illustrates the reduction in flow velocities during an 8-day drawdown period as the headpond elevation decreases.
10.1 Eel and Salmon Study In 2009 and 2010, NS Power completed tagging studies to assess the downstream movement of two migrating species at the Ruth Falls Dam: Atlantic salmon smolts and American eels. The intended outcome of the studies...
AI summary In 2009 and 2010, NS Power conducted tagging studies to assess the downstream movement of Atlantic salmon smolts and American eels at the Ruth Falls Dam. The studies aimed to evaluate the efficiency of the louver diversion system for fish passage. Results indicated approximately 30% efficiency for eels and over 90% for salmon smolts, though uncertainty remains regarding eel bypass effectiveness.
12.2.3 Upstream Eel Passage NS Power engaged Wood and Thaumas Environmental to assess and design upstream eel passage to support the upstream migration of elvers and juvenile eels. It was determined through the evaluation that a separate s...
AI summary NS Power is proposing an eel ramp to facilitate upstream eel passage, beyond the existing fishway. The design includes a metal box with climbing substrate and pumped water. The ramp will be placed outside the upper fishway and will cross over the fish ladder, with entrance conditions deemed suitable for eels based on hydraulic modeling.
CI 50518 NSUIARB IR-12 Attachment 12 Page 38 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) temporary access roads sit within the drawdown area. On the upstream side, access roads will be placed after the headpond has been drawn down a...
AI summary The text discusses the temporary access roads within a drawdown area, specifying that they will be placed after the headpond is drawn down. It mentions that over 70% of the roads will be installed above 91 ft elevation, materials will be removed post-work, and fish monitoring will be conducted by qualified individuals during the installation.
1.0 STUDY OVERVIEW In 2009 and 2010, NSP completed tagging studies toassess the downstreammovement of two migrating species at the Ruth Falls Dam: Atlantic salmon smolts and American eels. The intended outcome of the studies was to determi...
AI summary In 2009 and 2010, NSP conducted studies to assess fish passage efficiency at the Ruth Falls Dam, focusing on Atlantic salmon smolts and American eels. The 2010 study found that 57% of tagged eels successfully passed downstream, with 70% evading the louvres and 40% of those passing through turbines surviving but not recaptured for health assessment.
3.0 STUDY DETAILS Following the completion of improvement work, the assessment offish passage and the efficiency of the louvre diversion system was conducted over 2 years – the first taking place in 2009 and the second in 2010. In May 2009...
AI summary A study conducted by NSP over two years (2009-2010) assessed the efficiency of the louvre diversion system for fish passage. The study tracked salmon smolts and American eels using pit tags and antennas installed in the bypass.
REDACTED (CONFIDENTIAL INFORMATION REMOVED) CI 50518 NSUIARB IR-12 Attachment 12 Page 103 of 576 2009 / 2010 Eel Study Summary Ruth Falls Downstream Louvre System 1). The bypass was monitored continuously for the duration of the study up t...
AI summary A 2009/2010 study monitored the bypass system at Ruth Falls Downstream Louvre System for 48 hours after the last fish release to assess fish passage effectiveness.
CI 50518 NSUIARB IR-12 Attachment 12 Page 117 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) - 1. Existing weir configurations and louvres outflow configurations were modelled and resulted in poor attraction flows (see Figure 3) - 2. T...
AI summary Various configurations of weirs and louvres were tested to improve fish passage attraction flows. Initial designs resulted in poor attraction flows, and subsequent modifications, including weir redesign, rock diversion testing, and flow distribution adjustments, showed incremental improvements. However, strong currents from gate flows still disrupted attraction flows, and field verification may be needed post-construction.
3D CFD Modelling Once the details of the geometry were fully available and completely understood, a geometric model of the proposed structure (fully constructed), together with the fishway and downstream channel was assembled in Civil3D. T...
AI summary This section describes the process of creating a 3D CFD model using OpenFoam to analyze fish passage quality for different species. The model includes the proposed structure, fishway, and downstream channel, with boundary conditions set based on various flow scenarios. The model helps assess how well fish can navigate the fishway and be guided by attraction flows.
Modelling Results Each scenario (S1 to S7) contains 13 figures. Both plan views of the velocity magnitude, as well as cross-sections at regular intervals, with velocity vectors, are shown in panoramic views. - Figure 1 to Figure 3 : presen...
AI summary The document describes the visual representation of modelling results for scenarios S1 to S7, including plan views, cross-sections, and panoramic views showing velocity magnitudes and vectors. The colour scale was adjusted to highlight velocities from 0 to 2m/s, with a single colour for velocities above 2m/s.
CI 50518 NSUIARB IR-12 Attachment 12 Page 218 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Scenario Fishway Min Flow (cfs) Louvre Min Outflow (cfs) Gate Flow (cfs) Supplementary Flow (cfs) Total Flow (cfs) Scenario 7 6 29 0 n/a 35 Re...
AI summary The text presents a table with different flow scenarios, including fishway minimum flow, Louvre minimum outflow, gate flow, supplementary flow, and total flow. It includes two scenarios with specific values for each category, and a note about required supplementary flow that was not modelled but considered.
Proposed Scenario Based on the evaluation of the OpenFOAM model results, Scenario 1, with 6 cfs from the upper fishway and 29 cfs from the louvres (combining to provide 35cfs at the fishway entrance), and an additional 65cfs from the gates...
AI summary Scenario 1, with specific flow rates from the fishway, louvres, and gates, is proposed as the best for upstream fish passage, particularly for Eels. However, elvers and young eels may perform better in reality than modeled due to their movement patterns. An Eel pass is suggested to improve passage for American Eels past the dam.
CI 50518 NSUIARB IR-12 Attachment 12 Page 220 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) all upstream migrating age classes of eels. The best location for an American Eel pass is depicted on Figure 1 in Appendix A. This scenario pr...
AI summary The document discusses the impact of supplemental flow releases on fish passage, particularly for American Eels and Salmon. It highlights the need for specific flow rates and timing to ensure adequate passage depth for Salmon while also accommodating other species.
CI 50518 NSUIARB IR-12 Attachment 12 Page 228 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) 3 From June 15 to July 15 and September 26 to November 30 there are weekly supplemental flow events when the Ruth Falls headpond elevation is...
AI summary The document outlines supplemental flow events at Ruth Falls during specific periods to assist salmon migration. These events occur during significant inflow events and involve releasing water exceeding 50 cfs for at least 12 hours overnight. The flows are not modeled and fall between modeled minimum and maximum flows.
CI 50518 NSUIARB IR-12 Attachment 12 Page 267 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) level and the drop is taken up on 7 weirs. The first weir is located approximately 35 ft downstream of the concrete fishway then the weirs are...
AI summary The document describes the current fishway structure, including weir placement and dimensions, and the supplemental flow events aimed at assisting salmon migration. It notes that future dam construction will eliminate leakage and additional flow in this section.
Downstream passage The diadromous fish need to come back down past the dam at some point in their life cycle and resident species may choose to migrate down seeking suitable habitat. Some may come back down through the fishway or exit thro...
AI summary The text discusses the downstream passage of diadromous and resident fish species through a dam, highlighting the need for improvements to the current louver system. It notes that eels require specific design modifications, such as a solid wall near the bottom and a slated ramp to guide them to the surface outlet. The text also mentions the use of trap funnels and stop log sections to manage fish movement.
CI 50518 NSUIARB IR-12 Attachment 12 Page 272 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) orifices vs the overflow weirs in the concrete transition channel. This will ensure quick passage through a barrier free transition channel to...
AI summary The document discusses the design of a fish passage system, including orifices, overflow weirs, and a louver outflow pipe. It emphasizes ensuring quick passage through a barrier-free transition channel and compliance with USFW guidelines for safe downstream passage.
CI 50518 NSUIARB IR-12 Attachment 12 Page 277 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Major changes were undertaken during the rebuild of the louver bypass exit and monitoring shed operations based on Nova Scotia Power plans dat...
AI summary The document describes modifications made to the louver bypass exit and monitoring shed operations based on Nova Scotia Power plans from 2006. Changes included replacing the bottom outlet pipe with a surface outlet to improve salmon smolt migration. The intake canal was also reconstructed and widened in 2000 to enhance conveyance capacity.
5. American Eel ( Anguilla rostrata ) Silver Stage Downstream Passage With the recent focus on the American eel, NSPI has been asked to review potential options for improving the effectiveness of the louvers to bypass downstream migrating...
AI summary The document discusses the effectiveness of louvers at Ruth Falls in helping American eels bypass a dam during their downstream migration. Studies show only 56.7% of eels survived the passage, and the bypass design may allow eels to move back upstream due to flow patterns and channel structure, reducing overall efficiency.
CI 50518 NSUIARB IR-12 Attachment 12 Page 282 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Silver eels travel on the bottom of the watercourse with occasional movements up in the water column. They tend to spend considerable time mig...
AI summary The text discusses the migration behavior of silver eels, noting that they tend to stay near the bottom of watercourses and are insensitive to velocity changes until encountering obstructions. It highlights the effectiveness of deep bypasses over surface bypasses for downstream migrant eels and mentions that movements in the water column can lead eels to surface bypasses, spillways, or leakage points.
CI 50518 NSUIARB IR-12 Attachment 12 Page 283 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) the Alden modeling (Allen et al 2005) that indicates the velocities are good for guiding the eels to the bypass both at the bottom and along t...
AI summary The document discusses the effectiveness of louvers in guiding eels to a bypass and the need for design changes and modifications to improve passage efficiency. Observations show that eels are successfully reaching the bypass entrance, but further checks and repairs are needed, particularly during dam construction.
5.1 Lead the Eels to the Surface Outlet and Remove All Barriers Delaying Passage. The surface outlet is just 5 ft above the bottom but for eels traveling on the bottom, in fact usually in close contact with the bottom, this becomes a barri...
AI summary The text discusses the design of a sloping ramp to help eels navigate past a 5 ft barrier at the surface outlet. The ramp is intended to guide eels along the bottom, reducing search behavior and delays. It references studies by EPRI and similar implementations at other sites.
5.2 Keep the Fish in the Bypass Channel and Improve Downstream Passage In the concrete channel, it is proposed that a trap funnel be installed at the most upstream stop log guide. This funnel would narrow the opening to 1.25ft and lead the...
AI summary The proposal includes installing a trap funnel at the upstream stop log guide to narrow the opening and prevent fish from returning upstream, as well as modifying stop log sections to include bottom orifices to improve downstream passage for all species.
6. Conclusions - 1) The installation of a ramp and bottom walls along the louver will greatly improve entrance conditions for eel and other benthic species traveling along the bottom. This option would provide passage for yellow stage eels...
AI summary The document discusses the installation of a ramp and bottom walls along a louver to improve fish passage, particularly for eels and other benthic species. It highlights the importance of preventing upstream movement after fish enter the bypass and addresses flow velocity concerns. Stop logs with orifices are proposed to maintain adequate flow while ensuring downstream passage.
CI 50518 NSUIARB IR-12 Attachment 12 Page 291 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) APPENDIX J – UPSTREAM EEL PASSAGE ASSESSMENT
AI summary This section of the document provides an appendix titled 'Upstream Eel Passage Assessment,' which likely discusses the evaluation of fish passage issues related to eels in a hydroelectric or water management context.
3. Modern Eel Passes Generally, technical upstream fishways, such as fish ladders and fish lifts, are ineffective at passing juvenile eels. Therefore, specialized eel pass structures are required to provide a path for them over the dam (Vo...
AI summary Modern eel passes are specialized structures designed to help juvenile eels navigate dams. They consist of linear channels with climbing substrate and pumped water flow, and are designed to protect eels from predators. The entrance is uncovered to accommodate varying water levels over extended periods.
4.2 Flow Conditions Hydraulic modeling was used to identify flow patterns, velocities, and depths, downstream of the dam that support fish passage (including eels) under various flow scenarios. The results of this flow modelling have been...
AI summary Hydraulic modeling was used to determine flow conditions downstream of a dam that support fish passage, particularly for eels. The modeling identified suitable locations for eel pass entrances and highlighted resting areas along the river bottom and banks that eels use to navigate.
4.4 Design Criteria To meet the USFW service recommendations, the final design will include: - Construction Materials: - o Ramps, pools, and supporting structural elements will be built of rust-resistant metal (typically aluminum) or UV-st...
AI summary The design criteria for the eel ramp include construction materials, cover specifications, entrance design, climbing substrate, and exit elevation to meet USFW service recommendations. The design focuses on minimizing predation and ensuring accessibility for eels.
CI 50518 NSUIARB IR-12 Attachment 12 Page 298 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) - o Location: the exit is situated at the head pond between the fishway exit and the utility shed away from turbine intakes, spill gates, and...
AI summary This text describes the specifications for a fish passage ramp and resting sections, including dimensions, slope, water depth, and placement. The design aims to ensure safe passage for eels while avoiding structures that could cause entrainment.
5. Conclusions - 1) The young eels cannot effectively use the pool and weir fishway and require an eel pass to facilitate passage. - 2) A modern eel pass will be used at Ruth Falls, following the alignment shown in Figures 1 and 2. - 3) Th...
AI summary The conclusion outlines the need for an eel pass at Ruth Falls to assist young eels in navigating the fishway. The design will follow USFW 2019 criteria and include specific features such as an entrance on the downstream side and tiles suitable for eels of certain sizes.
3.6.1 Drone Surveys NS Power will apply the following methodology to characterize the habitat in Ruth Falls Headpond during the drawdown. A baseline drone survey, completed within one week of the drawdown will be conducted using a dronemou...
AI summary NS Power plans to use drone surveys to monitor habitat changes in Ruth Falls Headpond during and after a drawdown. Baseline surveys will be conducted before and after the drawdown, with follow-up surveys in November to assess shoreline evolution.
3.2.2 Fyke-Net Monitoring Fyke nets will be used during entrainment monitoring to assess other species and life stages of fish which may be entrained by the drawdown. Stantec proposes to set three fyke nets with ¼ inch mesh (6 mm) in suita...
AI summary Stantec proposes to use fyke nets with ¼ inch mesh during entrainment monitoring to assess fish species and life stages affected by the drawdown. Nets will be placed downstream of the dam, with alternate upstream locations available if needed. Deployment will occur at the start of the drawdown and nets will be checked periodically based on catch rates.
3.3 SHORELINE HABITAT CHARACTERIZATION Aerial imagery will be collected within the reservoir at set intervals to allow NS Power to document changes to aquatic habitat. Aerial imagery collection will consist of three surveys conducted durin...
AI summary Aerial imagery will be collected at specific intervals within the Ruth Falls Flowage reservoir to document changes in aquatic habitat. Surveys will be conducted in Early July 2024, August 2024, and November 2024 using a fixed-wing remotely piloted aircraft system operated by Aerovision. The imagery will be used by NS Power to produce geo-referenced orthomosaics and analyze habitat types and extents using GIS.
5.0 PROJECT SCHEDULE The proposed schedule for the 2024 Ruth Falls Entrainment Monitoring field program is outlined below. - Preliminary Field Visit for Site Selection (Completed) June 2022 - Baseline Aerial Shoreline Surveys Early July 20...
AI summary The 2024 Ruth Falls Entrainment Monitoring field program includes activities such as baseline surveys, flowage drawdown, and fish entrainment monitoring, with key milestones scheduled for July 2024 and March 2025.
CI 50518 NSUIARB IR-12 Attachment 12 Page 372 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) 3 # Indicators Condition Choices Data Definitions/Explanations OF18 Relative Elevation in In Google Earth, enable the Terrain layer (lower lef...
AI summary The text outlines indicators related to elevation and water quality in a specific area of assessment (AA). It provides instructions on using Google Earth and KMZ files to determine relative elevation and assess water quality sensitivity. The AA is evaluated for being in a protected water supply area and for signs of water degradation.
CI 50518 NSUIARB IR-12 Attachment 12 Page 420 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) A B C D E 213 Mostly passes through a pipe, culvert, narrowly breached dike, berm, beaver dam, or other partial obstruction (other than natura...
AI summary The text discusses criteria for identifying wetland characteristics, including water flow through natural and artificial features, tributary channels, and input water temperature. It outlines conditions for assessing wetland connectivity and water sources.
CI 50518 NSUIARB IR-12 Attachment 12 Page 440 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) A B C D E In the last column, place a check mark next to any item that is likely to have caused the timing of water inputs (but not necessaril...
AI summary The text discusses factors that may influence the timing of water inputs to a wetland, including stormwater from impervious surfaces, water subsidies from various sources, irrigation practices, flow regulation structures, and artificial modifications like dams, dikes, and drains.
CI 50518 NSUIARB IR-12 Attachment 12 Page 460 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) A B C D E 177 Zone within Wetland adjoining uplands from open water within the AA is: include wooded riparian areas if they have wetland soil...
AI summary The text discusses wetland evaluation criteria, specifically focusing on zones within wetlands, flat shoreline extent, and robust emergent vegetation. It provides guidelines for assessing the proximity of upland areas to wetlands, the percentage of flat shoreline, and the presence of specific vegetation types like cattail and bulrush.
1 Excavation within the wetland, e.g., dugout, artificial pond, dead-end ditch. Artificial drains or ditches in or near the wetland. Accelerated downcutting or channelization of an adjacent or internal channel (incised below the historical...
AI summary The text outlines various activities and factors that may affect wetland conditions, including excavation, drainage, logging, and contamination from stormwater or industrial sources. It provides a scoring system to assess the severity and spatial extent of these impacts on the wetland's timing of water conditions.
Table 1C. Ruth Falls Reservoir - Wetland Monitoring Results Net land 6 Wetland 6 HYDROLOGICAL I NDICATORS Baseline (July 2022) Y/N Baseline (September 2022) Y/N Notes HYDROLOGICAL OBSERVATIONS (POST ALT ERATION) Surface water er N Y Surfac...
AI summary Table 1C presents wetland monitoring results for the Ruth Falls Reservoir, focusing on hydrological indicators and vegetation data collected in July and September 2022. Key findings include changes in surface water saturation, drainage patterns, and shifts in plant species composition.
Table 1D. Ruth Falls Reservoir - Wetland Monitoring Results Netland 15 HYDROLOGICAL INDI CATORS Baseline (July 2022) Y/N Baseline (September 2022) Y/N Notes HYDROLOGICAL OBSERVATIONS (POST ALTERATION) Surface water N Y urface saturat Y Y •...
AI summary Table 1D presents wetland monitoring results for the Ruth Falls Reservoir, including hydrological indicators, vegetation plots, and soil type data collected in July and September 2022. The table highlights changes in surface water, vegetation percentages, and other environmental factors.
Monitoring strategy and techniques: - Visualization: - o Site pictures taken at each survey site and structure site. - Pictures will be taken with the same orientation and matched with the map(s) established in year 1 - o Will document pre...
AI summary The document outlines a comprehensive monitoring strategy for a river restoration project, including visualization techniques, habitat suitability index assessments, water temperature monitoring, and structure surveys. Methods such as site pictures, transect measurements, and drone usage are detailed to evaluate the project's environmental impact and effectiveness.
Larger View of project area Figure 2 Red marker indicates approximate area where restoration work will occur in comparison to the community of Sheet Harbour.
AI summary The document provides a visual representation of the project area, with a figure indicating the location of restoration work near the community of Sheet Harbour.
CI 50518 NSUIARB IR-12 Attachment 12 Page 569 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) - NSP tagged 148 eels, released them upstream the below Malay Falls dam, and detected 40 travelling through the bypass representing 30% effici...
AI summary The document discusses a study on fish passage at a dam in Nova Scotia, focusing on the migration of American eels and other species. NSP tagged and released eels, detecting a 30% efficiency in their movement through a bypass. The study also identified other species and outlines recommended modifications to the louver diversion system and fish ladder to improve passage.
2.2 Upstream migration monitoring It is worth noting that up to 15 sets of falls are located upstream on the East River between the Hydro generating station tailrace and the Ruth Falls dam. These natural outcroppings of bedrock represent a...
AI summary Upstream migration monitoring on the East River notes that 15 sets of falls between the Hydro generating station tailrace and the Ruth Falls dam act as partial barriers to alewife passage, particularly during high flow periods.
CI 50518 NSUIARB IR-12 Attachment 12 Page 571 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Innovasea to install two cameras in the fish ladder (one at the exit of the ladder and another at the entrance) and use AI technology to count...
AI summary Innovasea plans to install AI-powered cameras in a fish ladder to monitor fish movement, with similar programs already implemented at Whiterock and Tusket. Cameras will be installed in early April and monitored daily until June 15th in 2025 and 2026. Visual observations will also occur to assess any negative impacts from dam refurbishments.
Sea-run trout and Atlantic salmon NS Power will install pit tag antennas at the toe and the exit of the Ruth Falls fish ladder and will operate the trap in the fish ladder during the Atlantic salmon and trout migratory seasons to intercept...
AI summary NS Power plans to install pit tag antennas and operate a trap in the Ruth Falls fish ladder to monitor Atlantic salmon and sea-run trout during their migratory seasons. Fish will be tagged and released, and AI monitoring will be trained to recognize these species using camera data, though fish numbers may be insufficient for this goal.
Elvers A new elver rampwill be installed as part of the fish ladder upgrades. The structure will be designed to include a trap which will enable NS Powerto quantify the daily number of elvers ascending the ladder. This method is similar to...
AI summary A new elver ramp will be installed as part of fish ladder upgrades to help quantify elver migration. The method will be similar to one used on the East River Chester. Efficiency will be assessed using a fyke net and comparisons to sampling data. Elvers are expected to prefer previously used passage areas, and full efficiency may take time to achieve.
Pit Tagging Monitoring - For the proposed tagging study of downstream migrating Alewife, it is not clear if the target life stage is post spawn adult or juveniles. Please clarify. - Provide a more detailed description of the analysis to de...
AI summary The text includes several questions and requests for clarification regarding a proposed pit tagging monitoring study for Alewife and Gaspereau fish, including details on life stages, fish passage numbers, monitoring dates, and mitigation measures. The questions are posed by Alex Levy, Section Head at Regulatory Reviews – Ecosystems Management.