r200409 dunvegan hydraulics report 022205 · r200409 dunvegan hydraulics report 022205.doc ....

DUNVEGAN HYDROELECTRIC PROJECT

HYDRAULICS REPORT

Submitted To:

Calgary, Alberta

Submitted By:

Calgary, Alberta

January 2005

R200409 Dunvegan Hydraulics Report 022205.doc

Glacier Power Ltd. 200409 Dunvegan Hydroelectric Project January 2005 Hydraulics Report Page i

Table of Contents

1.0 INTRODUCTION................................................................................................................1 1.1 Background ...........................................................................................................1 1.2 Project Description ................................................................................................2 2.0 EXISTING INFORMATION AND WORK BY OTHERS.....................................................9 3.0 HYDRAULIC ANALYSES .................................................................................................9 3.1 Pre-Project Peace River Hydraulics ......................................................................9

3.1.1 General ......................................................................................................9 3.1.2 HEC-RAS Model Input Data ......................................................................9

3.1.2.1 River Cross Section Data...............................................................9 3.1.2.2 WSC Rating Curve at Town of Dunvegan ...................................11 3.1.2.3 Surveyed Water Surface Elevations ............................................11

3.1.3 Model Calibration.....................................................................................14 3.1.4 Project Tailwater Rating Curve ................................................................14

3.2 Project Hydraulics ...............................................................................................14 3.2.1 General ....................................................................................................14 3.2.2 Plant Flows ..............................................................................................16

3.2.2.1 Daily Flows...................................................................................16 3.2.2.2 Flood Flows..................................................................................16

3.2.3 Plant Configuration ..................................................................................23 3.2.4 Project Operational Rules and Guidelines...............................................25

3.2.4.1 Turbine Operation ........................................................................25 3.2.4.2 Upstream Fish Passage...............................................................26 3.2.4.3 Downstream Fish Passage ..........................................................26 3.2.4.4 Low Level Sluice Operation .........................................................26 3.2.4.5 River Flows That Exceed Full Powerhouse Capacity ..................27

3.2.5 Turbine, Spillway, and Powerhouse Rating Curves.................................27 3.2.6 Project Operating Rule Curves ................................................................34 3.2.7 Apportionment of Flows...........................................................................34

3.2.7.1 General ........................................................................................34 3.2.7.2 Turbine Sequencing and Utilization .............................................36

3.2.8 Flood Management..................................................................................36 3.2.8.1 General ........................................................................................36 3.2.8.2 Frequency of Powerhouse Overtopping ......................................41

3.2.9 Headpond Characteristics .......................................................................42 3.2.9.1 General ........................................................................................42 3.2.9.2 Water Surface Profiles .................................................................42 3.2.9.3 Velocities in the Headpond .........................................................48 3.2.9.4 Inundation ....................................................................................48 3.2.9.5 Headpond Volume .......................................................................48 3.2.9.6 Mean Resident Time....................................................................58

3.3 Screening Level Powerhouse and Spillway Structure Breach Inundation...........58

Glacier Power Ltd. 200409 Dunvegan Hydroelectric Project January 2005 Hydraulics Report Page ii

3.3.1 General ....................................................................................................58 3.3.2 Model Input Data .....................................................................................58 3.3.3 Dambreak Simulation ..............................................................................59

3.3.3.1 Failure Scenarios and Breach Parameters ..................................59 3.3.4 Results.....................................................................................................61

3.3.4.1 General ........................................................................................61 3.3.4.2 Town of Dunvegan and Highway 2 Bridge...................................61 3.3.4.3 Town of Peace River....................................................................69 3.3.4.4 Spillway Gate Failure ...................................................................69 3.3.4.5 Summary of Screening Level Analysis ........................................72

4.0 CORPORATE AUTHORIZATION ...................................................................................72

List of Appendices

Appendix I Monthly Operating Rule Curves Appendix II Headpond Water Levels and Average Velocities

List of Tables

Table 3.1 Water Surface Elevation Surveys........................................................................13 Table 3.2 Peace River at Dunvegan – Flood Flows ............................................................23 Table 3.3 Annual Operating Rule Curve..............................................................................35 Table 3.4 Flow Apportionment – Mean Weekly Discharge (1972-2003) .............................37 Table 3.5 Flow Apportionment – Mean Weekly Discharge (Wet Year 1976) ......................38 Table 3.6 Flow Apportionment – Mean Weekly Discharge (Dry Year 1980) .......................39 Table 3.7 Flow Apportionment – Mean Weekly Discharge (Normal Year 1994) .................40 Table 3.8 Frequency of Powerhouse Overtopping..............................................................41 Table 3.9 Naturalized and Post-Bennett Dam River Flows .................................................43 Table 3.10 Summary of Modelled Peace River Water Surface Elevations ...........................44 Table 3.11 Summary of Modelled Peace River Water Surface Elevation Changes from

Current Conditions ..............................................................................................44 Table 3.12 Summary of Modelled Peace River Mean Cross Section Flow Velocity .............49 Table 3.13 Summary of Modelled Peace River Mean Cross Section Velocity Changes from

Current Conditions ..............................................................................................49 Table 3.14 Comparison of Headpond Characteristics – Project Headpond vs. Current

Regime ................................................................................................................53 Table 3.15 FLDWAV Breach Modelling Data Inputs .............................................................59 Table 3.16 Failure Scenario Parameters...............................................................................60 Table 3.17 Summary of Modelling Results – Rapid (12 min) Failure Time ...........................62 Table 3.18 Summary of Modelling Results – Longer (60 min) Failure Time .........................63

Glacier Power Ltd. 200409 Dunvegan Hydroelectric Project January 2005 Hydraulics Report Page iii

List of Figures Figure 1.1 Overall Site Layout ................................................................................................3 Figure 1.2 Headworks, Plan ...................................................................................................4 Figure 1.3 Headworks, Elevation............................................................................................5 Figure 1.4 Powerhouse, Plan .................................................................................................6 Figure 1.5 Powerhouse, Sections...........................................................................................7 Figure 1.6 Spillway, Plan and Sections ..................................................................................8 Figure 1.7 Ramp Fishway and Boat Lock, Plan and Sections..............................................10 Figure 3.1 Rating Curve for WSC Peace River at Dunvegan Station...................................12 Figure 3.2 Tailwater Rating Curve........................................................................................15 Figure 3.3 Annual Flow Exceedance Curve .........................................................................17 Figure 3.4 Monthly Flow Exceedance Curves January, February, and March .....................18 Figure 3.5 Monthly Flow Exceedance Curves April, May, and June ....................................19 Figure 3.6 Monthly Flow Exceedance Curves July, August, and September .......................20 Figure 3.7 Monthly Flow Exceedance Curves October, November, and December ............21 Figure 3.8 Peace River Annual Flow Exceedance Curves – Regulated vs. Naturalized......22 Figure 3.9 Turbine Rating Curve ..........................................................................................28 Figure 3.10 Spillway Rating Curve (Gates Fully Down)..........................................................29 Figure 3.11 Spillway Rating Curve – Gates Operated............................................................30 Figure 3.12 Powerhouse Overtopping Rating Curve..............................................................31 Figure 3.13 Low Level Sluice Rating Curve ...........................................................................32 Figure 3.14 Upper Level Sluice Rating Curve ........................................................................33 Figure 3.15 Modelled Water Surface Profiles 5% Exceedance Flow .....................................45 Figure 3.16 Modelled Water Surface Profiles 50% Exceedance Flows..................................46 Figure 3.17 Modelled Water Surface Profiles 95% Exceedance Flows..................................47 Figure 3.18 Modelled Cross Section Velocity Profiles for 5% Exceedance Flow ...................50 Figure 3.19 Modelled Cross Section Velocity Profiles for 50% Exceedance Flow .................51 Figure 3.20 Modelled Cross Section Velocity Profiles for 95% Exceedance Flow .................52 Figure 3.21 Effect of Project Headpond on Inundated Areas (%)...........................................54 Figure 3.22 Effect of Project Headpond on Inundated Areas (ha)..........................................55 Figure 3.23 Effect of Project Headpond on River Volume (%) ...............................................56 Figure 3.24 Effect of Project Headpond on River Volume (dam3) ..........................................57 Figure 3.25 Screening Level Dam Breach Results – Maximum Water Level .........................64 Figure 3.26 Screening Level Dam Breach Results – Maximum Water Depth ........................65 Figure 3.27 Screening Level Dam Breach Results – Average Velocity..................................66 Figure 3.28 Screening Level Dam Breach Results – Peak Flow Rate ...................................67 Figure 3.29 Screening Level Dam Breach Results – Time to Peak Discharge ......................68 Figure 3.30 Peace River at the Town of Peace River Annual Flow Exceedance Curve ........70 Figure 3.31 Peace River at Town of Peace River Maximum Daily Discharge........................71

Glacier Power Ltd. 200409 Dunvegan Hydroelectric Project January 2005 Hydraulics Report Page 1

1.0 INTRODUCTION Glacier Power Ltd. is proposing a run-of-the-river hydroelectric plant located on the Peace River approximately two kilometres upstream of the Town of Dunvegan, Alberta. The proposed project entails constructing a powerhouse and spillway across the full width of the Peace River. The Project proposes to increase the water level in the river at the powerhouse by approximately six to seven metres to create differential head for the operation of a 100 MW low-head hydroelectric plant. The plant would produce power from the flow of the river without storing water; consequently, the project would not regulate or significantly change the river flows downstream of the plant.

The Project has evolved to a conceptual design level in consideration of alternatives from an engineering, environmental, and cost perspectives. Canadian Projects Limited (CPL) is Glacier Power Ltd.’s prime engineering consultant. Mack, Slack & Associates Inc. (MSA) has been retained by CPL to provide engineering services for the hydrologic and hydraulic aspects of the Project.

The objective of this study is to investigate the effects of the proposed Project on the hydraulic regime of the Peace River both upstream and downstream of the Project. To assess the Project impacts on the Peace River, the existing and historic hydraulic regime of the Peace River is compared to the predicted post-Project river regime. The results of this study are to be used by others to evaluate the Project effects on fish habitat and migration, navigation, fluvial geomorphology, valley slope stability, and ice mechanics.

All river hydraulic analyses and results presented herein presume open water conditions (i.e. not accounting for ice effects). The impacts of ice on the Project hydraulics and the impact of the Project on the Peace River ice regime is reported by others in a separate report.

1.1 Background Flows in the Peace River have been regulated since the construction of the W.A.C. Bennett Dam (constructed from 1967 to 1972) by B.C. Hydro, located near the Town of Hudson’s Hope, British Columbia, approximately 260 km upstream of Dunvegan. The Finlay and Parsnip Rivers were flooded forming Williston Lake, the reservoir impounded behind the Bennett Dam, to form the largest man-made lake in British Columbia. Williston Lake supplies the Bennett Dam’s hydroelectric generators, and the Peace River now flows from the reservoir’s eastern arm. The flow of water below the Bennett Dam marks the beginning of the Peace River. The Bennett Dam has significantly altered the flow and characteristics of the Peace River. The dam regulates flow releases seasonally to ensure peak energy generation during the winter months and daily during high electrical demands. Daily flows within the Peace River can fluctuate 250 m3/s approximately 50% of the time. Unregulated (i.e. prior to the Bennett Dam), the flows and levels within the Peace River varied seasonally, high flows in the spring during freshet, and lower flows in the winter. Regulation within the Peace River has significantly reduced the magnitude of spring floods, and significantly increased flows in the river in the winter.

From Bennett Dam, the Peace River flows eastward to the Peace Canyon Dam. The Halfway River flows into the Peace upstream of the Town of Fort St. John, British Columbia before it crosses the border into Alberta’s northern agricultural region.


The river continues east to the Town of Dunvegan. At Dunvegan the river valley is approximately 230 metres deep with steep valley slopes or escarpments. The river thalweg is approximately at elevation 337 m and the upland elevation is around 570 m above sea level.

Downstream of Dunvegan, the Peace River continues east to the Town of Peace River. The Town of Peace River is located approximately 96 km downstream of the Town of Dunvegan. Approximately six kilometres upstream of the Town of Peace River, the Smoky River joins the Peace River. Together with its tributaries, the Smoky River basin makes up approximately 20% of the Peace River basin at this point.

The Peace River flows into the Peace-Athabasca River delta, approximately 2,000 kilometres downstream of Bennett Dam, to form the Slave River.

The feasibility of a large dam hydroelectric facility at Dunvegan was previously studied by the Alberta Hydro Committee in the mid-1970s. Previous hydraulic studies carried out specifically for the Dunvegan Hydroelectric Project are “Dunvegan Hydro Project, Hydrology and Hydraulics Report, UMA Engineering Ltd., March 16, 2000.” This report updates and builds upon the UMA 2000 report.

1.2 Project Description The Dunvegan Project entails constructing a powerhouse, spillway, boat lock, and fishway structures across the Peace River. The project is located approximately two kilometres upstream of the Highway 2 bridge crossing at Dunvegan, Alberta. The Project will increase the water level in the river, upstream of the Project, by around six to seven metres to create adequate water level differential for the operation of a 100 MW low-head hydroelectric facility. Figure 1.1 shows the overall project layout and its vicinity to the Town of Dunvegan.

The powerhouse consists of 40 turbine units. Thirty units are located on the south side of the river and ten units are located on the north side. The powerhouse is separated by a 110 m wide gated, overflow spillway. Figures 1.2 and 1.3 show the plan and an elevation view of the proposed hydroelectric facility.

The powerhouse will contain the modular turbine units. The general arrangement of the powerhouse plan and sections are shown on Figures 1.4 and 1.5, respectively. The riverbed elevation at the powerhouse is 337 m. The top of the powerhouse is at elevation 348.4 m giving the structure a total height of 11.4 m. The powerhouse is approximately 285.7 m long. The powerhouse is designed to overtop during flood events that exceed the capacity of the turbines and gated overflow spillway.

The gated overflow spillway structure is 110 m long and has a fixed crest elevation of 344.4 m. The fixed ogee crest is approximately 7.4 m above the river bed. Adjustable overflow gates are proposed on the ogee crest in order to achieve headpond containment up to elevation 347.9 m (headpond level at powerhouse discharge capacity). Figure 1.6 shows the general arrangement of the spillway.


Fishways are required to provide safe passage of fish migrating upstream and downstream of the Project. As shown on Figure 1.2, a fishway is proposed to be located on each river bank. The fishways consist of a submerged vertical slot inlet (fish exit) to a ramp fishway to the outlet (fish entrance). The ramp fishway is shown on Figure 1.7.

As shown on Figures 1.2 and 1.7, a 8.5 m wide boat lock is proposed adjacent to the fishway ramp structure on the south bank of the river to retain navigability through the Project.

2.0 EXISTING INFORMATION AND WORK BY OTHERS Hydraulic studies for the characterization of the Project have been completed by several methods and consultants. Northwest Hydraulic Consultants’ (nhc) reports entitled “Dunvegan Hydroelectric Project, Right Bank Section Model, Technical Report, May 2003” and “Dunvegan Hydroelectric Project, Right Bank Section Model, Addendum to Technical Report, December 2003” present the results of numerous physical model tests of the powerhouse, spillway, and fishways. The UMA 2000 report presents the overall project hydrology and hydraulics. This MSA report, in conjunction with the MSA report entitled “Dunvegan Hydroelectric Project, Hydrology Report, August 2004”, are essentially an extension of the UMA 2000 report.

3.0 HYDRAULIC ANALYSES

3.1 Pre-Project Peace River Hydraulics

3.1.1 General

A one-dimensional hydraulic model was developed to characterize the open-water hydraulics of the Peace River in the vicinity of the Project. The hydraulic model was used to derive the predicted water levels at varying discharge immediately downstream of the Project and within the reach of river inundated in the proposed Project headpond.

The U.S. Army Corps of Engineers HEC-RAS v3.1.1 water surface profile computer program was used to characterize the river hydraulics.

3.1.2 HEC-RAS Model Input Data

Key input to the HEC-RAS computer model includes the geometric properties of the river (i.e. cross section shape and riverbed profile) and surveyed river water levels at varying discharges. The river water levels and corresponding flows are used to calibrate the hydraulic channel roughness characteristics of the river (Manning’s “n”) by re-running the HEC-RAS model with varying channel roughness’ until the surveyed water level at the corresponding river discharge is predicted in HEC-RAS. Once calibrated, the hydraulic model can be used to predict the river hydraulics for a range of flows.

3.1.2.1 River Cross Section Data

River cross section data was available from the following:

• River cross sections from Alberta Environment (AENV) at Sta. 0+599, -0+351, -0+771, -1+431, -2+141, -2+991, -3+661 circa 1987;


• River cross section from Water Survey of Canada (WSC) at Station -2+270; and,

• River cross sections surveyed by Skybase Surveying & Positioning (Skybase) (hired by Glacier Power) in 2001 at Station -0+120, -0+060, 0+000, 0+280, 4+095, 8+597, 11+691, 15+985, 18+239, and 26+000. Cross sections were derived using Global Positioning System (GPS) methods in conjunction with a depth sounder.

3.1.2.2 WSC Rating Curve at Town of Dunvegan WSC operates a streamflow monitoring gauge (WSC 07FD003) on the Peace River near the Dunvegan bridge approximately 2.27 km downstream of the Project. The rating curve and associated river cross section were obtained from WSC for inclusion in the HEC-RAS model to provide a calibrated water level at the downstream end of the study reach from which the hydraulic modelling upstream starts from. Having a calibrated reach of the Peace River in close proximity to the Project greatly improves the accuracy of the hydraulic model.

Figure 3.1 presents WSC’s rating curve for the Dunvegan gauge and the simulated rating curve based on the HEC-RAS modelling calibration both downstream and upstream of the WSC gauge. As evident in Figure 3.1, the HEC-RAS model calibrates closely to the WSC rating curve over the range of flows reported.

The WSC rating curve was used as the starting water elevation for the HEC-RAS simulations upstream.

3.1.2.3 Surveyed Water Surface Elevations Water surface elevations with corresponding river discharge are important in the calibration of the HEC-RAS model. Specifically, the river channel roughness, Manning’s “n” is adjusted to calibrate the model to accurately predict water levels based on available surveyed water elevations.

Water levels were surveyed throughout the study reach during site surveys undertaken in July and August 1999. The time of the water level observations were recorded and the corresponding discharge at this time was obtained from WSC flow measurement data. The water level elevation information from the 1999 survey program is included in Table 3.1.

Water elevation and discharge data encompassing a portion of the Project area was also obtained from AENV’s 1987 survey program. Nine (9) river cross sections and water levels were surveyed. The AENV cross section chainage was converted to the Project chainage to be able to incorporate the cross sections in the HEC-RAS model. The water level and corresponding discharge from AENV’s 1987 surveys are included in Table 3.1.

In November 2000, a GPS mounted small watercraft with an ultrasonic depth probe measured water level, water depth, and time at a 30 second time step as the boat floated down the river through the Project study reach. WSC hourly flow records at the Dunvegan gauge were obtained to provide the corresponding river discharge at the surveyed water level. Table 3.1 presents the surveyed water level and corresponding river discharge at the surveyed river cross sections.

MSA 200409Dunvegan Hydroelectric Project

10/18/04 - 8:39 AMFig 3.1 WSC Gauge 101104.xls - Fig 3.1 WSC Gauge

Figure 3.1Open Water Rating Curve for WSC Gauge 07FD003 - Peace River at Dunvegan Station

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Table 3.1 Water Surface Elevation Surveys

Date Water Elevation Discharge (m3/s)

River Station (m)

Source

July 7, 1999 339.91 1,152 -2+270 Glacier Power August 8, 1999 339.58 711 -2+100 Glacier Power July 7, 1999 340.78 1,186 -0+120 Glacier Power July 7, 1999 340.76 1,247 -0+060 Glacier Power July 7, 1999 340.79 1,186 0+280 Glacier Power July 9, 1999 342.19 1,251 4+095 Glacier Power July 8, 1999 342.85 1,352 8+597 Glacier Power July 8, 1999 344.21 1,326 11+691 Glacier Power July 8, 1999 344.98 1,331 15+985 Glacier Power July 8, 1999 346.01 1,360 18+239 Glacier Power August 8, 1999 347.35 719 26+000 Glacier Power July 25, 1987 340.96 2,714 -5+321 AENV July 25, 1987 340.96 2,714 -4+441 AENV July 25, 1987 341.22 2,714 -3+661 AENV July 25, 1987 341.39 2,714 -2+991 AENV July 25, 1987 342.56 2,714 -2+141 AENV July 25, 1987 341.57 2,714 -1+431 AENV July 25, 1987 341.77 2,714 -0+771 AENV July 25, 1987 342.15 2,714 -0+351 AENV July 25, 1987 342.40 2,714 0+599 AENV Nov. 3, 2000 340.41 1,529 -2+270 Skybase Nov. 3, 2000 340.55 1,529 -2+141 Skybase Nov. 3, 2000 340.72 1,529 -1+431 Skybase Nov. 3, 2000 341.04 1,529 -0+771 Skybase Nov. 3, 2000 341.28 1,529 -0+351 Skybase Nov. 3, 2000 341.38 1,529 -0+120 Skybase Nov. 3, 2000 341.40 1,529 -0+060 Skybase Nov. 3, 2000 341.44 1,529 0+000 Skybase Nov. 3, 2000 341.47 1,529 0+280 Skybase Nov. 3, 2000 341.40 1,529 0+599 Skybase Nov. 3, 2000 342.12 1,529 4+095 Skybase Nov. 3, 2000 343.10 1,529 8+597 Skybase Nov. 3, 2000 343.93 1,529 11+691 Skybase Nov. 3, 2000 345.06 1,529 15+985 Skybase Nov. 3, 2000 346.16 1,529 18+239 Skybase Nov. 3, 2000 348.52 1,529 26+000 Skybase Nov. 3, 2000 348.58 1,580 26+240 Skybase Nov. 3, 2000 348.61 1,580 26+360 Skybase


3.1.3 Model Calibration

The HEC-RAS model was calibrated such that the water levels simulated in the model closely matched the measured water levels at the surveyed cross sections presented in Table 3.1. The hydraulic roughness, Manning’s “n”, was varied at each cross section to calibrate the model to the measured water levels at the measured river discharges. Simulated water levels were within 0.02 to 0.24 m of the measured water levels. The calibrated Manning’s “n” values vary from 0.019 to 0.028 which is within the range expected for the hydraulic characteristics, bed material, and riparian vegetation evident within the Project study reach.

As mentioned in Section 3.1.2.3, the floatdown survey performed on November 3, 2000, provided a continuous measurement of water level and water depth at a 30 second time step. This data has been invaluable in calibrating the HEC-RAS model. The floatdown survey and the WSC rating curve at Dunvegan facilitate the creation of a one-dimensional hydraulic model that is deemed to be very accurate in characterizing the hydraulics, water level and average channel velocity of the Peace River within the Project study reach.

3.1.4 Project Tailwater Rating Curve

Figure 3.2 shows the derived project tailwater rating curve (water level versus Peace River discharge). The tailwater rating curve is taken immediately downstream of the Project and forms the basis for the proposed headpond water levels upstream of the Project. The tailwater rating curve is for open water conditions.

3.2 Project Hydraulics

3.2.1 General

The Dunvegan Hydroelectric Project consists of a powerhouse, spillway, boat lock, and fishway structures. The project spans the Peace River and will increase the water level in the river, upstream of the Project, by 5.4 to 7.8 m to create adequate water level differential for the operation of a 100 MW low-head hydroelectric facility. The Project hydraulics were analyzed at various river flows (i.e. low, average and high flows) and for river discharges representative of specific periods of the year to aid in assessing the implications of the Project on the Peace River hydraulic regime (i.e. water depth, velocity, sedimentation in the headpond, ice mechanics, etc.), fish passage, navigation, and flood management.

The project hydraulics presented herein presume open water conditions (i.e. not accounting for ice effects). The impact of ice on the project hydraulics and the impact of the Project on the Peace River ice regime is reported by others under separate cover.


10/18/04 - 8:40 AMFig 3.2 Tailwater Rating Curve 101104.xls - Rating Curve Chart

Figure 3.2Dunvegan Hydroelectric Project

Open Water Tailwater Rating Curve

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3.2.2 Plant Flows

3.2.2.1 Daily Flows MSA’s report entitled “Dunvegan Hydroelectric Project, Hydrology Report, August 2004” presents the project hydrology including pre and post-Bennett dam flows in the Peace River. The post-Bennett Dam flow regime has been utilized to assess the expected plant flows. The annual and monthly flow-exceedance curves (i.e. percentage of time that river flows are equal or exceeded) for the Peace River at Dunvegan since regulation by the Bennett Dam are used to characterize the Project daily flows. The WSC gauge at Dunvegan is not operated in the winter; consequently, the WSC gauge, Peace River at Peace River (WSC 07HA001), minus the WSC gauge, Smoky River at Watino (WSC 07GJ001), has been used to fill in the historic record at Dunvegan to include winter flows. The resulting annual flow exceedance curve, based on recorded mean daily discharge, is presented in Figure 3.3. Figure 3.3 shows that the flows in the Peace River exceed 753 m3/s, 1,540 m3/s, and 2,500 m3/s, 95%, 50%, and 5% of the time, respectively. Flow exceedance curves on a monthly basis were also determined and are included as Figures 3.4, 3.5, 3.6, and 3.7 for January to March, April to June, July to September, and October to December, respectively. Monthly flow exceedance curves are required to determine the Project hydraulics on a monthly basis to assess the implications on river hydraulics, powerhouse discharge, upstream and downstream fish passage hydraulics (i.e. guidance, attraction, and fish passage flows) during specific times of the year.

The effect of regulation on the Peace River due to the operation of the W.A.C. Bennett Dam is shown on Figure 3.8 which shows the annual flow exceedance based on the naturalized record of the Peace River (assuming that the Peace River was not regulated) versus the recorded post-Bennett Dam flows. As shown in Figure 3.8, regulation has had a significant impact on Peace River flows. Floods have been lessened and flows in the winter are substantially higher since regulation. Since the Dunvegan Hydroelectric Project is located downstream of the Bennett Dam, the regulated flow regime in the Peace River reduces the frequency of both extremely high and low river flows through the Project.

3.2.2.2 Flood Flows As mentioned previously, flows in the Peace River are regulated dependant on the releases of hydroelectric flows from the Bennett Dam. The operation of Williston Lake and the Bennett Dam has a significant impact on the expected flood flows at the Dunvegan Project. Depending on the reservoir water level in Williston Lake, floods could be significantly attenuated or completely stored in Williston Lake. To account for the significant attenuation of flood events in Williston Lake, the maximum instantaneous discharges recorded post-Bennett Dam have been used to determine expected flood flows through the Project. A flood frequency analysis is not strictly valid for a regulated Peace River since Williston Lake and the operation of Bennett Dam significantly attenuate peak flows and increases low flows which negates the randomness of the river flow data needed for the frequency analysis to be statistically valid. The approach, methodology, and results of the flood frequency analyses for the Dunvegan Project are included in the MSA 2004 Hydrology Report. Table 3.2 presents the results of the peak instantaneous discharge for the 1:2, 1:5, 1:10, 1:20, 1:50, 1:100, 1:200, 1:500, and 1:1000 year floods.

MSA 200409Dunvegan Project

8/05/04 - 11:02 AMP:\Projects\MSA 2004\200409 Dunvegan Hydrology and Hydraulics\Hydrotechnical Report\

Fig 3.3 to 3.7 Dunvegan regulated FDC.xls - Fig 3.3

Figure 3.3Annual Flow Exceedance Curve

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Fig 3.3 to 3.7 Dunvegan regulated FDC 022205.xls - Fig 3.4

Figure 3.4Monthly Flow Exceedance Curves

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Fig 3.3 to 3.7 Dunvegan regulated FDC.xls - Fig 3.8 Post and Nat Flow Exc

Figure 3.8Peace River Annual Flow Exceedance Curves - Regulated vs. Naturalized Flow

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)

Naturalized FlowPost-Bennett Dam


In this report, “naturalized discharge or flow” at Dunvegan is defined as the discharge that would have occurred in the Peace River at Dunvegan if Bennett Dam had not been constructed. A data set of natural daily flows at Dunvegan was obtained by combining historical pre-Bennett flows with naturalized flows for the post-Bennett period (since 1972). The naturalized flow record was developed by routing Williston Reservoir inflows from Hudson Hope to Dunvegan, accounting for intermediate inflows. A detailed description of the derivation of daily naturalized discharges is included in the MSA 2004 Hydrology Report. Table 3.2 presents the results of frequency analyses carried out on the naturalized discharge at Dunvegan. As evident in Table 3.2, the routing effect of Williston Lake has significantly reduced the flood flows at Dunvegan.

Table 3.2 Peace River at Dunvegan – Flood Flows

Return Period (Years)

Post-Bennett Dam Peak Instantaneous Discharge

(m3/s)

Naturalized Discharge Peak Instantaneous Discharge

(m3/s) 1:2 3,680 7,490 1:5 4,920 9,120

1:10 5,750 10,200 1:20 6,540 11,300 1:50 7,570 12,700

1:100 8,330 13,800 1:200 9,100 14,900 1:500 10,100 16,600

1:1000 10,900 17,800

3.2.3 Plant Configuration

The proposed Project is a run-of-river hydroelectric facility that does not rely on storage for power production. Rather, the facility requires differential head across the plant for power production. As there is no flow attenuation, flows into the headpond are the same as the flows out of the Project.

The general arrangement of the powerhouse is shown on Figures 1.4 and 1.5. The top of the powerhouse is at elevation 348.4 m giving the powerhouse structure a total height of 11.4 m. The powerhouse discharge capacity is approximately 1,800 m3/s based on 40 turbine units, each with a discharge capacity of approximately 45 m3/s. In actuality, the turbine units have a discharge capacity varying between 42.3 m3/s and 46.7 m3/s for differential heads of 5.4 m and 7.6 m, respectively. The 40 turbine units are simple propeller turbines (i.e. Kaplan turbines without regulated blades or wicket gates). At full capacity each unit produces 2.5 MW. Some turbines will be shut down entirely when the river flows are less than the powerhouse capacity.

The powerhouse is designed to overtop during significant flood events that exceed the capacity of the turbines and gated overflow spillway. When the powerhouse is overtopped, it is assumed that significant flow over the discharge outlets of the turbine units will create undesirable pulsations and require the plant to shutdown.


The gated overflow spillway structure general arrangement is shown on Figure 1.6. The fixed crest elevation of the spillway is 344.4 m. The fixed ogee crest is approximately 7.4 m above the river bed. Adjustable overflow gates are proposed on the ogee crest in order to achieve headpond containment up to an elevation of 347.9 m. This water level corresponds to the headpond level at full powerhouse discharge capacity. At flows greater than the powerhouse discharge capacity, the overflow gates are lowered to maintain water levels below the top of the powerhouse (El. 348.4 m). The gates are fully lowered during larger, more extreme flood events. Overflow gates are selected because they do not impede flow during significant flood events. The gates are well suited for the Dunvegan Project because trees, ice and other large debris can be passed unimpeded over the spillway gates and powerhouse.

Two submerged orifice ramp fishways are proposed, one per riverbank. Locating one fishway per riverbank ensures that migrating fish along each riverbank can pass through the Project. The submerged orifice ramp fishways are shown on Figure 1.7. Extensive physical model testing has been carried out by Northwest Hydraulic Consultants (nhc) on the performance of the fishway structures (nhc May 2003 and December 2003). As a result of these studies, the optimum design discharge for each fishway is 2 m3/s. An auxiliary water system is currently being considered to introduce additional flow into the ramp fishway at different locations along the ramp to provide attraction flow for upstream migrating fish. The auxiliary water system (AWS) may have a total discharge capacity of 100 m3/s.

The ramp is 10 m wide and approximately 132 m long. The ramp configuration has been optimised to facilitate upstream fish passage for the target fish species and life stages within the Peace River. The design discharge of 2 m3/s provides the velocity distribution and flow depths within the ramp fishway suitable for upstream fish passage. The submerged orifice fishway at the upstream end of the ramp is 5.25 m wide and is 48.3 m long. The submerged orifice fishway consists of nine vertical slot orifices (a lower level orifice with an invert elevation of 341 m and an upper level orifice with an invert elevation of 346 m) to convey the fishway design discharge of 2 m3/s over the expected range of headpond levels while providing suitable velocities across the orifices to facilitate the upstream passage of the target fish species and life stage. The top of the walls at the upstream side of the ramp fishway are at elevation 354 m; thereby, diverting all flood events out of the fishway.

In addition to the two submerged orifice ramp fishways, ten low-level and nine upper-level fish sluices are located within the powerhouse to facilitate downstream fish passage through the facility. The low-level fish sluices consist of a 2.5 m wide by 2.8 m high conduit with a 600 mm diameter orifice incorporated into a vertical slide gate. The 600 mm diameter orifice facilitates finer gate operation at lower river flows. During large river flows that exceed the capacity of the powerhouse and overflow spillway, the vertical slide gates in the low-level sluices are opened.

In addition to the low-level fish sluices, nine upper-level fish sluices consisting of 400 mm diameter conduits are provided in the powerhouse. Figure 1.5 shows the low-level and upper-level fish sluices through the powerhouse.

An 8.5 m wide boat lock is proposed adjacent to the submerged orifice, ramp fishway structure on the south bank of the river to retain navigability through the Project. The general arrangement of the boat lock is shown on Figure 1.7.


3.2.4 Project Operational Rules and Guidelines

The Project is a run-of-river hydroelectric facility. Consequently, river flows into the Project flow through the project unimpeded. The operational rules and guidelines adopted for the proposed Project account for the fact that the river discharges vary considerably from day to day and even hour to hour depending on the releases from Bennett Dam. In addition to the operational rules and guidelines for power generation, operational rules are required to accommodate upstream and downstream fish passage and boat navigation through the Project. The operational rules accommodate the following project premises:

• The powerhouse discharge capacity is approximately 1,800 m3/s; 40 turbine units at a capacity of between 42 m3/s and 46.5 m3/s for differential heads of 5.7 m and 7.6 m, respectively. The width of the powerhouse is 285.7 m.

• Two submerged orifice ramp fishways, one per riverbank, are provided. The design discharge for each fishway is 2 m3/s. An auxiliary water system (AWS) may also be provided within the fishways to introduce flows into the ramp at different locations depending on tailwater levels. The auxiliary water system would have a capacity of 100 m3/s per fishway. The auxiliary water system operates during the upstream fish migration period only. At low river flows (i.e. 95% exceedance), the AWS design discharge is 3 to 5 m3/s per fishway. At the 50% exceedance flow, the AWS discharge is 10 m3/s per fishway and 25 to 30 m3/s per fishway at the 5% exceedance flow.

• Ten low-level and nine upper-level fish sluices are located within the powerhouse. The low-level fish sluices are sized to convey approximately 20 m3/s at a differential head of 6 m. The upper level fish sluices consist of a 400 mm diameter conduit.

• The spillway consists of a fixed ogee crest and an overshot gate. The fixed crest elevation is 344.4 m and the gates are 3.5 m high. The effective spillway ogee crest length is 100 m.

• The upstream fish migration season is primarily from April to June; however, the submerged orifice ramp fishways are operated during the open water season (April 1 to October 31st). Fishway attraction flow is provided by the adjacent turbine units with guidance flow being provided via a guidewall located at the downstream end of the powerhouse.

• In combination with the AWS system, the low level fish sluice adjacent to the ramp fishway is required to pass 5 to 10 m3/s per sluice at the 95% exceedance flow, 14 m3/s at the 50% exceedance flow, and 40 to 45 m3/s at the 5% exceedance flow.

• The downstream fish migration season is from July to October.

3.2.4.1 Turbine Operation The turbine units will be turned on or off depending on the river flows. For the operation of the turbine units, the combination of which turbines are on or off is dictated firstly by the river discharge. Secondly, the preferential operation of the turbines is dependant on the following:

• During the upstream fish migration period (April to July), the turbine units and low-level fish sluice adjacent to the fishway ramp and the auxiliary water system will be operated to provide optimum guidance/attraction flow. During the downstream fish migration period


(July to October), the turbine units and the fish sluices will be operated to obtain optimum entrainment/attraction flow to the fish sluices.

• Whenever possible, turbine units will be shutdown for a practical minimum period. That is, the operational plan for the turbines attempts to limit the degree of operation required by minimizing the number of start/stops for all of the units. The current assumption is that, as much as practicable, the turbine units will be shutdown for a minimum two week period.

• The sequencing of selective operation will be determined to run all of the turbines for approximately the same length of time (i.e. the percentage of time each turbine is operating is relatively the same based on an annual basis).

3.2.4.2 Upstream Fish Passage Upstream fish passage is accommodated in the current project configuration via the submerged orifice ramp fishway structures located on each riverbank. The submerged orifice fishway design discharge is 2 m3/s. The flows into the submerged orifice fishways are dependant on the headpond level; therefore, a trimming gate is proposed adjacent the inlet to augment flows in the fishway ramp.

Fishway attraction/guidance flows are provided via the ramp fishway, the adjacent fish sluice located between the ramp fishway and the powerhouse, the auxiliary water system within the ramp fishway, and the submerged orifice conduits in a guidewall at the outlet (fish inlet) of the fishway. Flow to the submerged orifice conduits in the guidewall is via the turbine units and low-level fish sluices located adjacent each fishway. The operational rule for the critical upstream fish passage season of April to June is to run selected turbine units, the auxiliary water system, and fish sluice closest to the fishway throughout the upstream fish passage season. In instances when the river discharge is less than full powerhouse discharge, turbine units located away from the fishways (i.e. in the middle of the powerhouse) would be selectively shutdown.

3.2.4.3 Downstream Fish Passage Downstream fish passage is accommodated in the current project configuration via:

• Ten low-level and nine upper-level fish sluices located through the powerhouse; • The submerged orifice ramp fishways; • For larger river flows that exceed powerhouse capacity, via the overflow spillway; and, • For small fish, via fish-friendly turbines. Three of the ten low-level fish sluices are operated during the critical downstream fish passage season (July to October). When possible, the turbine units adjacent the operating low-level fish sluice will be selected and operated to improve guidance/attraction flow to the low-level fish sluice.

3.2.4.4 Low Level Sluice Operation The turbine units have a discharge capacity varying between 42 m3/s and 46.5 m3/s for differential heads of 5.7 m and 7.6 m, respectively. The 40 turbine units are simple propeller turbines (i.e. Kaplan turbines without regulated blades or wicket gates) and do not have the capability of fine discharge control; consequently, depending on flows available for power


generation, multiple turbines are operated to convey the power generation flow but turbine operation alone will likely not be able to exactly convey all of the river flow without resulting in minor changes in headpond level. To allow fine discharge control, while maintaining a more constant headpond level, the operational plan assumes that one or several of the low-level fish sluices are operated to match the river inflow. The low-level fish sluice adjacent the control tower is operated preferentially for fine discharge control while providing guidance/attraction flow to the adjacent ramp fishway.

3.2.4.5 River Flows That Exceed Full Powerhouse Capacity When river flows are below or near full powerhouse capacity, the low-level fish sluices are used to fine tune water levels and avoid discharge over the spillway. When the inflows exceed powerhouse and low-level fish sluice capacity, the spillway is then used to maintain headpond levels. In the event of a load rejection, the sequence of operation will be dependant on the inflow at the time of the event. If the inflows are greater than the total low-level fish sluice capacity, the spillway will be the primary release facility. The turbine units, upper-level fish sluices, submerged orifice fishways, and the fishway ramp auxiliary water system are shutdown when the river flows result in overtopping of the powerhouse.

3.2.5 Turbine, Spillway, and Powerhouse Rating Curves

Rating curves were produced for each hydraulic conveyance structure. Figure 3.9 shows the turbine rating curve (i.e. project head versus discharge) for one turbine unit. Figure 3.10 shows the spillway rating curve (headpond level versus spillway discharge) assuming that the adjustable overflow gates are fully down. The rating curve for when spillway flows are over the adjustable overflow gates in either the fully up or partially operated position (i.e. between fully up and fully down) are dependant on the desired headpond level. Figure 3.11 shows the rating curve for the spillway when the adjustable overflow gates are operated to maintain a headpond level at the top of the powerhouse (elevation 348.4 m) assuming that all of the spillway gates are operated. A combination of one or all of the spillway gates could be operated to maintain headpond levels. Figure 3.12 shows the rating curve (headpond level versus overflow discharge) of the powerhouse when it is overtopped. Figure 3.13 shows the rating curve for one low level fish sluice (project head versus discharge) and Figure 3.14 shows the rating curve for one upper level fish sluice.



project rating curve 100804.xls - Fig 3.9 Turbine Rating Curve


Turbine Rating Curve

5

5.5

6

6.5

7

7.5

8

42.0 42.5 43.0 43.5 44.0 44.5 45.0 45.5 46.0 46.5 47.0

Turbine Discharge per Unit (m3/s)

Diff

eren

tial H

ead

Hea

dpon

d Le

vel -

Tai

lwat

er L

evel

(m)



project rating curve 100804.xls - Fig 3.10 Spillway Rating Curve

Figure 3.10 Dunvegan Hydroelectric Project

Spillway Rating Curve (Gates Fully Down)

342

344

346

348

350

352

354

356

358

0 1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000 9,000

Spillway Discharge (m3/s)

Hea

dpon

d El

evat

ion

(m)

Top of PowerhouseEl. 348.4 m

Spillway Fixed CrestEl. 344.4 m



project rating curve 100804.xls - Fig 3.11 Gate Rating Curve

Figure 3.11 Dunvegan Hydroelectric Project

Spillway Gates Rating Curve

344

344.5

345

345.5

346

346.5

347

347.5

348

0 200 400 600 800 1,000 1,200 1,400 1,600 1,800

Discharge over Spillway Gates (m3/s)

Top

of G

ate

Elev

atio

n (m

)



project rating curve 080304.xls - Fig 3.12Powerhouse Rating Curve


Powerhouse Rating Curve (Overtopping)

348

349

350

351

352

353

354

355

356

357

0 2,000 4,000 6,000 8,000 10,000 12,000

Overtopping Discharge (m3/s)

Hea

dpon

d El

evat

ion

(m)

Top of PowerhouseEl. 348.4 m



project rating curve 100804.xls - Fig 3.13 Low Level Sluice Curve


Low Level Fish Sluice Rating Curve

4

4.5

5

5.5

6

6.5

7

7.5

8

8.5

9

40 41 42 43 44 45 46 47 48 49 50 51 52 53 54

Low Level Sluice Discharge (m3/s)

Proj

ect H

ead

(m)

Low Level Sluice (one sluice only)



project rating curve 080304.xls - Fig 3.14 Upper Sluice Rat Curve


Upper Level Fish Sluice Rating Curve

346

346.5

347

347.5

348

348.5

349

0.5 0.6 0.7 0.8 0.9

Upper Level Sluice Discharge (m3/s)

Hea

dpon

d Le

vel (

m)

Upper Level Sluice (one sluice only)


3.2.6 Project Operating Rule Curves

Table 3.3 presents the annual plant operating rule curve which includes the plant headpond, tailwater elevations, and gross project heads for a range of river flows and incorporates the hydraulic rating curves presented in Section 3.2.5. River flows presented include the 100% to 0% exceedance flow (defined as the percentage of time the river flows are equal to or greater) and the 1:2, 1:5, 1:10, 1:20, 1:50, 1:100, 1:200, 1:500, and 1:1000 year flood events. The rule curve presents the proposed allocation of river flow for the various Project components. For example, the river flow proposed for fish passage via the upper and low-level fish sluices and ramp fishways, and the remaining flow available for power generation are presented. As discussed in Section 3.2.4.5, a turbine unit conveys a discharge of between 42.3 and 46.7 m3/s depending on the available head. Table 3.3 shows the number of turbines operating at a given river flow. Residual river discharge (i.e. discharge in excess of what the turbines can convey) is conveyed via the low-level sluices to provide fine flow control.

Tables I.1 to I.12 in Appendix I present the project rule curves on a monthly basis. The monthly rule curves present the differing operational requirements depending on upstream and downstream fish passage. For example, the ramp fishways are operated in the open water season only (April to October).

The key items to note as shown in Table 3.3 and I.1 to I.12 are:

• Normal operating gross head varies from 5.4 m to 7.6 m depending on river discharge.

• Headpond level fluctuates during plant operation from a minimum elevation of 347.3 m to the top of powerhouse elevation of 348.4 m.

• The powerhouse is overtopped at a river discharge of 3,380 m3/s. As mentioned previously, it is assumed that the turbines, fishways and upper-level fish sluices are shutdown once the powerhouse is overtopped.

• At the 1:100 year flood event of 8,330 m3/s, the headpond elevation is 352.2 m and the tailwater level is 346.0 m, a difference of 6.2 m in water level. During the 1:1000 year flood event of 10,900 m3/s, the headpond elevation is 353.2 m and the tailwater level is 347.2 m, a difference of 6.0 m in water level.

• Based on the annual rule curve presented in Table 3.3, all of the turbines operate approximately 20% of the time.

• The spillway operates approximately 10% of the time on an annual basis.

3.2.7 Apportionment of Flows

3.2.7.1 General The rule curves presented in Table 3.3 and Table I.1 to I.12 present the allocation of river flows across the various Project components (i.e. powerhouse, spillway, sluices, and fishways) on an annual and monthly basis. To be able to assess the percentage of time the individual turbine units are operating, the project operational requirements and guidelines were applied to the mean weekly discharge for the following:

Table 3.3Annual Operating Rule Curve

% Exceedance and Flood Events

River Discharge

Turbine Status

Tailwater Elevation

Headwater Elevation

Project Head

Number of Units

Operating

Power Flow

Powerhouse Overflow

Spillway Flow

Submerged Orifice

Fishways

Fishway Attraction

Flow - AWS

Upper-Level Fish

Sluices

Low-Level Fish

Sluices

(m3/s) (m) (m) (m) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s)100% 425 Operating 339.5 347.1 7.60 7 324 0 0 4 10 2 8598% 619 Operating 339.9 347.5 7.60 11 509 0 0 4 10 2 9495% 753 Operating 340.1 347.7 7.60 14 648 0 0 4 10 2 8890% 905 Operating 340.4 347.9 7.50 17 784 0 0 4 11 2 10480% 1,120 Operating 340.7 347.9 7.20 22 1,003 0 0 4 13 2 9870% 1,290 Operating 340.9 347.9 7.00 26 1,177 0 0 4 16 2 9160% 1,430 Operating 341.1 347.9 6.80 29 1,302 0 0 4 18 2 10450% 1,540 Operating 341.2 347.9 6.70 32 1,431 0 0 4 20 2 8240% 1,640 Operating 341.4 347.9 6.50 34 1,508 0 0 4 29 2 9630% 1,750 Operating 341.5 347.9 6.40 37 1,635 0 0 4 38 2 7120% 1,880 Operating 341.6 347.9 6.30 40 1,760 0 0 4 47 2 6710% 2,150 Operating 341.9 348.4 6.50 40 1,775 0 171 4 56 3 1425% 2,500 Operating 342.2 348.4 6.20 40 1,752 0 543 4 60 3 1392% 3,020 Operating 342.7 348.4 5.70 40 1,713 0 1,107 4 60 3 133

At Overtopping 3,380 Operating 343.0 348.4 5.40 40 1,691 0 1,492 4 60 3 130Overtopping 3,380 Shut-Down 343.0 349.7 6.68 0 0 745 2,427 0 0 0.0 209

1:2 yr. 3,680 Shut-Down 343.2 349.9 6.66 0 0 907 2,552 0 0 0.0 2211:5 Year 4,920 Shut-Down 344.1 350.6 6.47 0 0 1,644 3,065 0 0 0.0 2111:10 Year 5,750 Shut-Down 344.6 351.0 6.39 0 0 2,144 3,383 0 0 0.0 2231:20 Year 6,540 Shut-Down 345.1 351.4 6.28 0 0 2,645 3,688 0 0 0.0 2061:50 Year 7,570 Shut-Down 345.7 351.9 6.15 0 0 3,295 4,067 0 0 0.0 208

0% 7,600 Shut-Down 345.7 351.9 6.16 0 0 3,310 4,075 0 0 0.0 2151:100 Year 8,330 Shut-Down 346.0 352.2 6.18 0 0 3,779 4,340 0 0 0.0 2111:200 Year 9,100 Shut-Down 346.4 352.5 6.10 0 0 4,269 4,611 0 0 0.0 2201:500 Year 10,100 Shut-Down 346.9 352.9 6.02 0 0 4,942 4,974 0 0 0.0 1841:1000 Year 10,900 Shut-Down 347.2 353.2 6.02 0 0 5,442 5,239 0 0 0.0 219

Powerhouse Fish Sluices Low Upper Spillway Gate Up Gate Down Note: Presumes open water conditions onlyC 1.8 C 0.6 0.98 C varies 1.6 2.0 (not accounting for ice effects)Width (m) 285.7 Size/Dia. 2.5x2.8 0.4 Width (m) 100Fixed Crest 348.4 Number 10 9 Fixed Crest 344.4

# Operating 3 3 Max. Gate Height (m) 3.5 3.5Invert El. 337 345.7

P:\Projects\MSA 2004\200409 Dunvegan Hydrology and Hydraulics\Hydrotechnical Report\Dunvegan Rule Curves msa 111704.xls11/18/04 Table 3.3 Annual Rule Curve


• from 1972-2003 (i.e. post Bennett Dam);

• a normal river flow year (1994);

• a wet year (1976); and,

• a dry year (1980).

3.2.7.2 Turbine Sequencing and Utilization Tables 3.4 to 3.7 present the flow apportionment on a mean weekly basis for the aforementioned time periods presented in Section 3.2.7.1. Flows required for upstream and downstream fish passage are included in Tables 3.4 to 3.7 assuming that the ramp fishways are operational during the open water season (i.e. April to October) and the low-level sluices are operated to facilitate downstream fish passage from July to October. It is assumed that the upper-level sluices are operated at the same time as the immediately adjacent low-level sluices.

As shown on Table 3.4, the turbines operate approximately 83% of the time on average for the mean weekly discharge since the construction of the Bennett Dam and 81%, 81%, and 60% of the time for a normal river flow year (Table 3.5), a wet year (Table 3.6), and a dry year (Table 3.7), respectively. Turbines are, as much as practicable, shutdown for a minimum two week period. The turbine units located closest to the ramp fishways are preferentially operated during the critical upstream fish migration season of April to June.

3.2.8 Flood Management

3.2.8.1 General During low river flows (i.e. river flows less than the discharge capacity of the 40 turbine units), the spillway gates would be raised to their fully up position (i.e. top of gate elevation of 347.9 m), and all of the river flow would be conveyed via the turbines, fish sluices, and ramp fishways depending on the time of year. During higher river flows that exceed the total discharge capacity of the 40 turbine units, the spillway gates would be lowered to safely convey the net spillway flow (river flow minus the turbine, sluices, and ramp fishway flows) without overtopping the powerhouse (top of powerhouse elevation of 348.4 m). During extreme flood events (i.e. river discharges exceeding the 1.5% annual exceedance flow of 3,380 m3/s), the spillway gates are fully down and the powerhouse is overtopped. As mentioned previously, it is assumed that the turbines, upper-level sluices, and ramp fishways are shutdown once the powerhouse is overtopped.

Table 3.3 shows the differential head (i.e. difference between headpond and tailwater level) when the powerhouse is overtopped. During the 1:2 year annual flood, the differential head is approximately 6.7 m lessening to around 6 m during the 1:1000 year flood. Tables I.1 to I.12 present the project rule curves on a monthly basis. As shown in Tables I.1 to I.12, the powerhouse is not expected to be overtopped in the months of January, November, and December for flood events up to, and including, the 1:1000 year flood for these respective months.

Table 3.4Dunvegan Hydroelectric Project

Flow Apportionment - Mean Weekly Discharge (1972-2003)

Week Date Mean Weekly Tailwater Project Headwater Fishway S.W. Turbines (T1 to T5) S.W. Turbines (T6 to T10) S.W. Spillway/Powerhouse Overtopping S.W. Turbines (T11 to T15) S.W. Turbines (T16 to T20) S.W. Turbines (T21 to T25) S.W. Turbines (T26 to T30) S.W. Turbines (T31 to T35) S.W. Turbines (T36 to T40) Tower Fishway Boat Launch Total Project DifferenceStarting River Discharge Elevation Head Elevation & AWS S1 T1 T2 T3 T4 T5 S2 T6 T7 T8 T9 T10 S3 S4 T11 T12 T13 T14 T15 S5 T16 T17 T18 T19 T20 S6 T21 T22 T23 T24 T25 S7 T26 T27 T28 T29 T30 S8 T31 T32 T33 T34 T35 S9 T36 T37 T38 T39 T40 S10 & AWS Operating/ Flow

(cms) (m) (m) (m) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) (cms) Not Operating (cms) (cms)

1 Jan-01 1549.1 341.3 6.6 347.9 0 0 44 44 0 44 44 0 44 44 44 44 0 0 0.0 0 44 44 44 44 44 0 44 44 0 44 44 0 44 44 0 44 44 0 44 44 0 44 44 0 44 44 44 44 44 0 44 44 44 44 44 9 0 Not Operating 1549.1 0.02 Jan-08 1554.5 341.3 6.7 348.0 0 0 45 0 0 45 45 0 45 45 45 45 0 0 0.0 0 45 45 45 45 45 0 45 45 0 45 45 0 45 45 0 45 45 0 45 45 0 45 45 0 45 45 45 45 45 0 45 45 45 45 45 25 0 Not Operating 1554.5 0.03 Jan-15 1507.0 341.2 6.7 347.9 0 0 45 0 0 45 45 0 45 45 45 45 45 0 0.0 0 45 45 0 45 45 0 45 45 0 45 45 0 45 45 0 45 45 0 45 45 0 45 45 0 45 45 0 45 45 0 45 45 45 45 45 22 0 Not Operating 1507.0 0.04 Jan-22 1470.5 341.2 6.7 347.9 0 0 45 0 0 45 45 0 45 45 0 45 45 0 0.0 0 45 45 0 45 45 0 45 45 0 45 45 0 45 45 0 45 45 0 45 45 0 45 45 0 45 45 0 45 45 0 45 45 45 45 45 31 0 Not Operating 1470.5 0.05 Jan-29 1475.1 341.2 6.7 347.9 0 0 45 45 0 45 45 0 45 45 0 45 45 0 0.0 0 45 45 0 45 45 0 45 45 0 45 45 0 45 45 0 45 45 0 45 45 0 45 45 0 45 45 0 45 45 0 45 45 0 45 45 35 0 Not Operating 1475.1 0.06 Feb-05 1495.8 341.2 6.7 347.9 0 0 45 45 45 45 45 0 45 45 0 0 45 0 0.0 0 45 45 45 0 45 0 45 45 45 0 45 0 45 45 45 0 45 0 45 45 45 45 45 0 45 45 45 0 45 0 45 45 0 45 45 11 0 Not Operating 1495.8 0.07 Feb-12 1516.8 341.2 6.7 347.9 0 0 45 45 45 45 45 0 45 45 45 0 45 0 0.0 0 45 45 45 0 45 0 45 45 45 0 45 0 45 45 45 0 45 0 45 45 45 45 45 0 45 45 45 0 45 0 45 0 0 45 45 42 0 Not Operating 1526.8 10.08 Feb-19 1434.4 341.1 6.8 347.9 0 0 45 45 45 0 45 0 45 45 45 0 45 0 0.0 0 45 45 45 0 45 0 45 0 45 0 45 0 45 45 45 45 45 0 45 45 45 0 45 0 45 45 45 0 45 0 45 0 0 45 45 39 0 Not Operating 1434.4 0.09 Feb-26 1392.6 341.1 6.8 347.9 0 0 45 45 45 0 45 0 45 45 45 0 45 0 0.0 0 45 45 45 0 45 0 45 0 45 0 45 0 45 45 45 45 45 0 45 45 45 0 45 0 45 45 45 0 0 0 45 0 0 45 45 43 0 Not Operating 1392.6 0.010 Mar-05 1387.0 341.1 6.8 347.9 0 0 45 45 45 45 45 0 45 45 0 45 45 0 0.0 0 45 0 0 45 45 0 45 45 45 45 45 0 45 0 45 45 0 0 45 0 45 45 0 0 45 0 45 45 0 0 45 0 45 45 45 37 0 Not Operating 1387.0 0.011 Mar-12 1369.6 341.0 6.9 347.9 0 0 45 45 45 45 45 0 45 0 0 45 45 0 0.0 0 45 0 0 45 45 0 45 45 45 45 45 0 45 0 45 45 0 0 45 0 45 45 0 0 45 0 45 45 0 0 45 45 45 45 45 20 0 Not Operating 1369.6 0.012 Mar-19 1389.5 341.1 6.8 347.9 0 0 45 45 45 45 45 0 45 0 45 45 45 0 0.0 0 45 0 45 45 45 0 45 0 0 45 45 0 45 0 0 45 45 0 45 45 0 45 0 0 45 0 0 45 45 0 45 45 45 45 45 40 0 Not Operating 1389.5 0.013 Mar-26 1389.0 341.1 6.8 347.9 0 0 45 45 45 45 45 0 45 0 45 45 45 0 0.0 0 0 45 45 45 45 0 0 0 0 45 45 0 45 45 0 45 45 0 45 45 0 45 0 0 0 45 0 45 45 0 45 45 45 45 45 39 0 Not Operating 1389.0 0.014 Apr-02 1461.3 341.1 6.8 347.9 12 14 45 45 45 45 45 0 45 45 45 45 0 0 0.0 0 0 45 45 45 0 0 0 45 45 45 45 0 0 45 45 45 45 0 0 45 0 45 45 0 0 45 0 45 45 0 45 45 45 45 45 28 12 Operating 1461.3 0.015 Apr-09 1557.8 341.3 6.6 347.9 12 14 44 44 44 44 44 0 44 44 44 44 0 0 0.0 0 0 44 44 44 0 0 44 44 44 44 44 0 0 44 44 44 44 0 0 44 44 44 44 0 0 44 44 44 44 0 44 44 44 44 44 24 12 Operating 1557.8 0.016 Apr-16 1728.6 341.5 6.4 347.9 12 14 44 44 44 44 44 0 44 44 44 44 44 0 0.0 0 44 44 44 44 0 0 44 44 44 44 44 0 0 44 44 44 44 0 44 44 44 44 44 0 44 44 44 44 44 0 44 44 44 44 44 19 12 Operating 1728.6 0.017 Apr-23 1976.0 341.7 6.7 348.4 12 14 45 45 45 45 45 0 45 45 45 45 45 0 124.0 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 14 12 Operating 1976.0 0.018 Apr-30 1886.5 341.6 6.3 347.9 12 14 44 44 44 44 44 0 44 44 44 44 44 0 74.5 0 44 44 44 44 44 0 44 44 44 44 44 0 44 44 44 44 44 0 44 44 44 44 44 0 44 44 44 44 44 0 44 44 44 44 44 14 12 Operating 1886.5 0.019 May-07 1871.6 341.6 6.5 348.1 12 14 44 44 44 44 44 0 44 44 44 44 44 0 59.6 0 44 44 44 44 44 0 44 44 44 44 44 0 44 44 44 44 44 0 44 44 44 44 44 0 44 44 44 44 44 0 44 44 44 44 44 14 12 Operating 1871.6 0.020 May-14 2005.8 341.8 6.6 348.4 12 20 45 45 45 45 45 0 45 45 45 45 45 0 141.8 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 20 12 Operating 2005.8 0.021 May-21 1942.4 341.7 6.7 348.4 12 14 45 45 45 45 45 0 45 45 45 45 45 0 90.4 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 14 12 Operating 1942.4 0.022 May-28 2045.5 341.8 6.6 348.4 12 20 45 45 45 45 45 0 45 45 45 45 45 0 181.5 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 20 12 Operating 2045.5 0.023 Jun-04 2003.3 341.8 6.6 348.4 12 20 45 45 45 45 45 0 45 45 45 45 45 0 139.3 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 20 12 Operating 2003.3 0.024 Jun-11 2199.6 342.0 6.4 348.4 12 30 44 44 44 44 44 0 44 44 44 44 44 0 355.6 0 44 44 44 44 44 0 44 44 44 44 44 0 44 44 44 44 44 0 44 44 44 44 44 0 44 44 44 44 44 0 44 44 44 44 44 30 12 Operating 2199.6 0.025 Jun-18 1940.4 341.7 6.7 348.4 12 20 45 45 45 45 45 0 45 45 45 45 45 0 76.4 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 20 12 Operating 1940.4 0.026 Jun-25 1735.7 341.5 6.4 347.9 12 14 44 44 44 44 44 0 44 44 0 44 44 0 0.0 0 44 44 0 44 44 0 44 44 44 44 44 0 44 44 44 44 44 0 44 44 44 44 44 0 44 44 44 44 44 0 44 44 44 44 44 26 12 Operating 1735.7 0.027 Jul-02 1676.8 341.4 6.5 347.9 12 0 44 44 44 44 44 20 44 44 0 44 44 20 0.0 20 44 44 0 44 0 0 0 44 44 44 44 0 44 44 44 44 44 0 44 44 44 44 44 0 44 44 44 44 44 0 44 44 44 44 44 9 12 Operating 1677.0 0.228 Jul-09 1667.3 341.4 6.5 347.9 12 20 44 44 44 44 44 20 0 44 44 44 44 20 0.0 20 0 44 0 44 0 0 0 44 44 44 44 0 44 44 44 44 44 0 44 44 44 44 44 0 44 44 44 44 44 0 44 44 44 44 44 23 12 Operating 1667.3 0.029 Jul-16 1695.9 341.4 6.5 347.9 12 0 44 44 44 44 44 0 44 44 44 44 44 0 0.0 0 44 44 44 44 44 0 44 44 44 44 44 20 44 44 44 44 0 20 0 44 44 0 0 20 44 44 44 44 44 20 44 44 44 44 44 8 12 Operating 1695.9 0.030 Jul-23 1523.4 341.2 6.7 347.9 12 0 45 45 45 45 45 0 0 45 45 45 45 0 0.0 0 45 45 45 45 45 20 45 45 45 45 45 20 45 45 45 45 0 20 0 45 45 0 0 0 0 45 45 45 0 20 45 45 45 0 0 24 12 Operating 1523.4 0.031 Jul-30 1415.1 341.1 6.7 347.8 12 0 45 45 45 0 0 0 0 0 45 45 0 20 0.0 20 45 45 45 45 45 20 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 0 0 45 45 45 0 0 0 0 45 0 0 26 12 Operating 1415.1 0.032 Aug-06 1310.0 341.0 6.7 347.7 12 20 0 45 45 0 0 0 0 0 45 45 0 20 0.0 20 0 0 45 45 45 0 45 45 45 45 0 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 0 0 0 0 0 45 45 45 11 12 Operating 1310.0 0.033 Aug-13 1207.3 340.8 7.1 347.9 12 20 0 45 45 45 45 0 45 45 45 0 45 0 0.0 0 45 0 0 0 45 20 0 0 45 0 0 20 0 0 45 0 0 20 0 0 45 45 45 0 45 45 45 0 45 0 45 45 45 45 45 23 12 Operating 1207.3 0.034 Aug-20 1250.3 340.9 7.0 347.9 12 20 0 45 0 45 45 0 45 45 45 45 45 0 0.0 0 45 45 0 0 0 20 0 0 45 0 0 20 0 0 45 0 0 20 0 0 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 21 12 Operating 1250.3 0.035 Aug-27 1212.0 340.8 7.1 347.9 10 0 0 45 0 0 0 20 0 0 45 0 0 20 0.0 20 0 0 45 45 45 0 45 45 45 45 45 0 45 45 0 45 45 0 45 45 45 45 45 0 45 45 45 0 0 0 0 0 45 45 45 7 10 Operating 1212.0 0.036 Sep-03 1189.9 340.8 7.1 347.9 10 0 0 45 0 0 0 0 0 0 45 0 0 20 0.0 20 0 0 45 45 45 20 45 45 45 45 45 20 45 45 0 45 45 0 45 45 45 45 45 0 45 45 45 0 0 0 0 0 45 45 0 10 10 Operating 1189.9 0.037 Sep-10 1310.4 341.0 6.9 347.9 12 0 45 45 45 45 45 0 45 45 45 45 45 0 0.0 0 45 45 45 0 0 20 0 0 45 0 0 20 0 0 45 0 0 20 0 0 45 45 45 0 45 45 45 0 45 0 45 45 45 45 45 11 12 Operating 1310.4 0.038 Sep-17 1375.4 341.0 6.9 347.9 12 0 45 45 45 45 45 0 45 45 45 45 45 0 0.0 20 45 45 45 0 0 20 0 0 45 0 0 20 0 0 45 0 0 20 0 0 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 11 12 Operating 1375.4 0.039 Sep-24 1328.5 341.0 6.9 347.9 12 0 45 45 45 0 0 20 0 0 45 0 0 20 0.0 20 0 45 45 45 45 0 45 45 45 45 45 0 45 45 45 0 45 20 45 0 45 0 0 0 0 0 45 45 45 0 45 45 45 45 45 10 12 Operating 1328.5 0.040 Oct-01 1364.5 341.0 6.9 347.9 12 0 45 45 45 0 0 20 0 0 45 0 0 20 0.0 20 0 45 45 0 45 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 0 0 0 0 0 45 45 45 0 45 45 45 45 45 21 12 Operating 1364.5 0.041 Oct-08 1412.6 341.1 6.8 347.9 12 0 45 45 45 45 0 0 45 45 45 45 45 0 0.0 0 45 45 45 0 0 20 0 0 45 0 0 20 0 0 45 45 45 0 45 45 45 45 0 20 0 45 45 45 45 0 45 45 45 45 45 24 12 Operating 1412.6 0.042 Oct-15 1469.9 341.2 6.7 347.9 12 0 45 45 45 45 0 0 45 45 45 45 45 0 0.0 0 45 45 45 45 0 20 0 45 45 0 0 20 0 0 45 45 45 20 45 45 45 45 45 0 45 45 45 45 0 20 0 45 0 45 45 16 12 Operating 1469.9 0.043 Oct-22 1475.7 341.2 6.7 347.9 12 0 45 45 45 45 45 0 45 45 45 45 45 20 0.0 0 45 45 45 45 45 0 45 45 45 45 0 0 45 45 45 0 0 20 0 0 45 45 45 20 45 45 45 0 0 20 0 0 0 45 45 22 12 Operating 1475.7 0.044 Oct-29 1490.7 341.2 6.7 347.9 11 0 45 45 45 45 45 0 45 45 45 45 45 0 0.0 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 0 0 20 0 0 45 0 45 20 0 0 45 45 45 20 45 0 45 45 0 13 11 Operating 1490.7 0.045 Nov-05 1521.1 341.2 6.7 347.9 0 0 0 0 45 45 45 0 45 45 45 45 45 0 0.0 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 0 45 0 0 0 45 45 45 20 45 45 45 0 0 16 0 Not Operating 1521.1 0.046 Nov-12 1501.0 341.2 6.7 347.9 0 0 0 0 45 45 45 0 45 45 45 45 45 0 0.0 0 45 0 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 0 0 45 0 0 0 16 0 Not Operating 1501.0 0.047 Nov-19 1570.5 341.3 6.6 347.9 0 0 45 0 45 45 45 0 45 45 45 45 45 0 0.0 0 45 0 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 0 45 45 20 0 45 0 0 45 21 0 Not Operating 1570.5 0.048 Nov-26 1617.9 341.3 6.6 347.9 0 0 45 0 45 45 45 0 45 45 45 45 45 0 0.0 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 0 45 45 45 45 45 0 45 0 0 45 45 20 0 45 45 0 45 23 0 Not Operating 1617.9 0.049 Dec-03 1641.3 341.4 6.5 347.9 0 0 44 44 0 44 44 0 44 44 44 44 44 0 0.0 0 44 44 44 44 44 0 44 44 44 44 44 0 44 44 44 44 44 0 44 44 44 44 44 0 44 44 0 44 44 0 44 44 44 44 0 13 0 Not Operating 1641.3 0.050 Dec-10 1639.1 341.4 6.5 347.9 0 0 44 44 0 44 44 0 44 44 44 44 44 0 0.0 0 44 44 44 44 44 0 44 44 44 44 44 0 44 44 44 44 44 0 44 44 44 44 44 0 44 44 44 44 44 0 44 44 44 0 0 11 0 Not Operating 1639.1 0.051 Dec-17 1648.0 341.4 6.5 347.9 0 0 44 0 44 44 44 0 44 44 44 44 44 0 0.0 0 44 44 44 44 44 0 44 44 0 44 44 0 44 44 44 44 44 0 44 44 44 44 44 0 44 44 44 44 44 0 44 44 44 0 44 20 0 Not Operating 1648.0 0.052 Dec-24 1517.7 341.2 6.7 347.9 0 0 45 0 45 45 0 0 45 45 0 45 45 0 0.0 0 45 45 45 45 45 0 45 45 0 45 45 0 45 45 45 45 45 0 45 45 0 45 45 0 45 45 0 45 45 20 45 45 45 0 45 13 0 Not Operating 1517.7 0.0

SUM OF WEEKLY FLOWS 367.35 302 2012 1923 1880 1967 1922 100 1968 1922 1969 1922 1879 180 1243.7 180 1924 1922 1880 1877 1881 180 1879 1922 1924 1877 1967 180 1924 1922 1923 1922 1878 200 1879 1922 1923 1968 1923 80 1878 1967 1878 1877 1877 180 1922 1877 1922 1924 1969 1076.13 367.35MEAN ANNUAL FLOW 7.1 5.8 38.7 37.0 36.2 37.8 37.0 1.9 37.8 37.0 37.9 37.0 36.1 3.5 23.9 3.5 37.0 37.0 36.2 36.1 36.2 3.5 36.1 37.0 37.0 36.1 37.8 3.5 37.0 37.0 37.0 37.0 36.1 3.8 36.1 37.0 37.0 37.8 37.0 1.5 36.1 37.8 36.1 36.1 36.1 3.5 37.0 36.1 37.0 37.0 37.9 20.7 7.1TURBINES

2012 1923 1880 1967 1922 1968 1922 1969 1922 1879 1924 1922 1880 1877 1881 1879 1922 1924 1877 1967 1924 1922 1923 1922 1878 1879 1922 1923 1968 1923 1878 1967 1878 1877 1877 1922 1877 1922 1924 196986.9% 83.1% 81.2% 85.0% 83.1% 85.0% 83.1% 85.1% 83.1% 81.2% 83.1% 83.1% 81.2% 81.1% 81.3% 81.2% 83.1% 83.1% 81.1% 85.0% 83.1% 83.1% 83.1% 83.1% 81.2% 81.2% 83.1% 83.1% 85.0% 83.1% 81.2% 85.0% 81.2% 81.1% 81.1% 83.1% 81.1% 83.1% 83.1% 85.1%

Average Percent of Time Turbine Running 82.9%Minimum Percent of Time Turbine Running 81.1%Maximum Percent of Time Turbine Running 86.9%

Note: Presumes open water conditions only (not accounting for ice effects).

Total Weekly Discharge Per TurbinePercent of Time Turbine Running


11/18/049:44 AMP:\Projects\MSA 2004\200409 Dunvegan Hydrology and Hydraulics\Hydrotechnical Report\

Apportionment of mean weekly river flows 111704.xls-Mean Weekly


Flow Apportionment - Mean Weekly Discharge (Wet Year 1976)




SUM OF WEEKLY FLOWS 607 482.9 1906 1907 1863 1906 1862 180 1817 1861 1860 1816 1818 260 19194.9 320 1817 1861 1859 1862 1818 320 1817 1815 1905 1906 1905 300 1861 1906 1905 1860 1861 240 1862 1860 1905 1905 1905 220 1905 1863 1905 1905 1861 190 1907 1949 1860 1907 1904 1269.6 607MEAN ANNUAL FLOW 11.7 9.3 36.7 36.7 35.8 36.7 35.8 3.5 34.9 35.8 35.8 34.9 35.0 5.0 369.1 6.2 34.9 35.8 35.8 35.8 35.0 6.2 34.9 34.9 36.6 36.7 36.6 5.8 35.8 36.7 36.6 35.8 35.8 4.6 35.8 35.8 36.6 36.6 36.6 4.2 36.6 35.8 36.6 36.6 35.8 3.7 36.7 37.5 35.8 36.7 36.6 24.4 11.7TURBINES

1906 1907 1863 1906 1862 1817 1861 1860 1816 1818 1817 1861 1859 1862 1818 1817 1815 1905 1906 1905 1861 1906 1905 1860 1861 1862 1860 1905 1905 1905 1905 1863 1905 1905 1861 1907 1949 1860 1907 190482.4% 82.4% 80.5% 82.4% 80.5% 78.5% 80.4% 80.4% 78.5% 78.6% 78.5% 80.4% 80.3% 80.5% 78.6% 78.5% 78.4% 82.3% 82.4% 82.3% 80.4% 82.4% 82.3% 80.4% 80.4% 80.5% 80.4% 82.3% 82.3% 82.3% 82.3% 80.5% 82.3% 82.3% 80.4% 82.4% 84.2% 80.4% 82.4% 82.3%






Apportionment of mean weekly river flows 111704.xls-Wet Year 1976 new


Flow Apportionment - Mean Weekly Discharge (Dry Year 1980)




SUM OF WEEKLY FLOWS 319.5 212.7 1408 1406 1498 1446 1448 120 1408 1405 1403 1403 1402 180 30.6 180 1363 1447 1401 1451 1449 100 1358 1406 1404 1405 1451 100 1406 1357 1403 1450 1450 180 1406 1403 1401 1407 1409 80 1408 1400 1402 1359 1403 340 1404 1401 1359 1405 1411 834.919 321MEAN ANNUAL FLOW 6.1 4.1 27.1 27.0 28.8 27.8 27.8 2.3 27.1 27.0 27.0 27.0 27.0 3.5 0.6 3.5 26.2 27.8 26.9 27.9 27.9 1.9 26.1 27.0 27.0 27.0 27.9 1.9 27.0 26.1 27.0 27.9 27.9 3.5 27.0 27.0 26.9 27.1 27.1 1.5 27.1 26.9 27.0 26.1 27.0 6.5 27.0 26.9 26.1 27.0 27.1 16.1 6.2TURBINES

1408 1406 1498 1446 1448 1408 1405 1403 1403 1402 1363 1447 1401 1451 1449 1358 1406 1404 1405 1451 1406 1357 1403 1450 1450 1406 1403 1401 1407 1409 1408 1400 1402 1359 1403 1404 1401 1359 1405 141160.2% 60.1% 64.0% 61.8% 61.9% 60.2% 60.0% 60.0% 60.0% 59.9% 58.2% 61.8% 59.9% 62.0% 61.9% 58.0% 60.1% 60.0% 60.0% 62.0% 60.1% 58.0% 60.0% 62.0% 62.0% 60.1% 60.0% 59.9% 60.1% 60.2% 60.2% 59.8% 59.9% 58.1% 60.0% 60.0% 59.9% 58.1% 60.0% 60.3%






Apportionment of mean weekly river flows 111704.xls-Dry Year 1980 new


Flow Apportionment - Mean Weekly Discharge (Normal Year 1994)




SUM OF WEEKLY FLOWS 408 372.5 1912 1909 1870 1865 1865 160 1910 1866 1868 1867 1865 180 1515.0 180 1866 1865 1868 1867 1864 160 1866 1866 1912 1865 1862 140 1865 1862 1864 1909 1866 120 1864 1908 1869 1865 1866 60 1866 1863 1866 1913 1910 235 1864 1866 1866 1868 1867 1133.9 408MEAN ANNUAL FLOW 7.8 7.2 36.8 36.7 36.0 35.9 35.9 3.1 36.7 35.9 35.9 35.9 35.9 3.5 29.1 3.5 35.9 35.9 35.9 35.9 35.8 3.1 35.9 35.9 36.8 35.9 35.8 2.7 35.9 35.8 35.8 36.7 35.9 2.3 35.8 36.7 35.9 35.9 35.9 1.2 35.9 35.8 35.9 36.8 36.7 4.5 35.8 35.9 35.9 35.9 35.9 21.8 7.8TURBINES

1912 1909 1870 1865 1865 1910 1866 1868 1867 1865 1866 1865 1868 1867 1864 1866 1866 1912 1865 1862 1865 1862 1864 1909 1866 1864 1908 1869 1865 1866 1866 1863 1866 1913 1910 1864 1866 1866 1868 186782.6% 82.5% 80.8% 80.6% 80.6% 82.5% 80.6% 80.7% 80.7% 80.6% 80.6% 80.6% 80.7% 80.7% 80.6% 80.6% 80.6% 82.6% 80.6% 80.5% 80.6% 80.5% 80.6% 82.5% 80.6% 80.6% 82.5% 80.8% 80.6% 80.6% 80.6% 80.5% 80.6% 82.7% 82.5% 80.6% 80.6% 80.6% 80.7% 80.7%






Apportionment of mean weekly river flows 111704.xls-Normal Year 1994 new


3.2.8.2 Frequency of Powerhouse Overtopping Table 3.3 indicates that the powerhouse is overtopped for river flows that are greater than the 1.5% annual exceedance flow of 3,380 m3/s. The turbines are shutdown when the powerhouse is overtopped. Historic daily river discharges recorded since 1972 (post-Bennett Dam) were analysed to determine the number of days per year the powerhouse would have been overtopped if the Project existed since 1972. Table 3.8 presents the number of days that the powerhouse is overtopped.

In 1972 and 1996 abnormal releases occurred from Bennett Dam. In 1972, Williston Lake was still filling and in 1996 emergency releases were made to accommodate repairs at Bennett Dam.

As shown in Table 3.8, the powerhouse is overtopped on average 4.4 days per year (i.e. approximately 1.5% of the time since 1972) when discounting the significant releases that occurred in 1996.

Table 3.8 Frequency of Powerhouse Overtopping

Year Number of Days Powerhouse is Overtopped

Year Number of Days Powerhouse is Overtopped

1972 29 1989 0 1973 0 1990 8 1974 7 1991 0 1975 0 1992 0 1976 20 1993 0 1977 3 1994 1 1978 0 1995 0 1979 1 1996 62 1980 0 1996 (revised) 12 1981 0 1997 18 1982 0 1998 0 1983 14 1999 0 1984 11 2000 0 1985 0 2001 8 1986 0 2002 3 1987 5 2003 0 1988 0

Total Number of Days Including 1996 190 Average Number of Days/Year 5.9 Total Number of Days Revised for 1996 140 Average Number of Days/Year Revised for 1996 4.4


3.2.9 Headpond Characteristics

3.2.9.1 General The Project will form a headpond that extends approximately 27 km upstream; consequently, water levels would increase and flow velocities would decrease in this reach of the Peace River. To be able to assess the implications that the Project would have on water levels and flow velocities within the headpond, the U.S. Army Corps of Engineers water surface profile program, HEC-RAS, was used to characterize the river hydraulics. River hydraulics within the headpond were determined for the naturalized discharges (i.e. historic flows that would have occurred without regulation at the Bennett Dam), post-Bennett flows (i.e. historic flows recorded since the operation of the Bennett Dam), and post-Dunvegan flows (i.e. historic flows recorded since the operation of the Bennett Dam routed through the proposed Dunvegan Project). Water levels and average channel velocities were determined for the aforementioned three flow scenarios and the results are discussed in the following sections.

3.2.9.2 Water Surface Profiles The calibrated HEC-RAS model discussed in Section 3.1 was used to determine the water surface elevations at surveyed river cross sections located within the headpond upstream of the Project. Specifically, water surface elevations were determined at 11 locations (Project Station 0+000, 0+280, 0+599, 4+095, 8+597, 11+691, 15+985, 18+239, 26+000, 26+240, and 26+360).

Naturalized and post-Bennett river flows were used to assess the implications of the Project on river water levels within the headpond. The river flows analysed are summarized in Table 3.9.

The results of the analysis are summarized in Table 3.10 which presents the modelled water level within the headpond for the 5%, 50%, and 95% exceedance flows for the naturalized flow, and the post-Bennett Dam flow with, and without, the Project. Table 3.11 presents a comparison of the changes in water level from the current flow regime (i.e. post-Bennett Dam flows) to naturalized discharges (no regulation due to Bennett Dam) and post-Bennett Dam water levels with the Project. Figures 3.15 to 3.17 show the computed water surface profiles for the naturalized discharges and post-Bennett Dam flows with, and without, the Project for the 5%, 50%, and 95% exceedance flows, respectively. As shown in Table 3.11 and Figures 3.15 to 3.17, the water level increase at the Project (Station 0+000) varies from 6.07 m for the 5% exceedance flow to 7.57 m for the 95% exceedance flow. The naturalized discharge would be 2.15 m greater than the post-Bennett Dam regime (3.92 m less than the water level proposed for the Project) for the 5% exceedance flow and 1.32 m less than the post-Bennett Dam flow regime (8.89 m less than the water level proposed for the Project). The increase in water level within the Project headpond diminishes farther upstream of the headworks. As evident in Table 3.11, the increase in water depth at Station 26+360 is 0.46 m, 0.31 m, and 0.61 m for the 5%, 50%, and 95% exceedance flows, respectively. Essentially, the impact of the Project headpond is that the water levels in approximately 26.4 km of river are increased independent on the flow within the river.

Table II.1 in Appendix II presents the computed water levels within the proposed headpond for the post-Bennett Dam flow regime, with and without the Project, and the naturalized discharges


at each surveyed river cross-section within the reach of river inundated by the Project. Table II.1 presents the water levels for the 100% to 0% exceedance flows and the 1:2, 1:5, 1:10, 1:20, 1:50, 1:100, 1:200, 1:500, and 1:1000 year flood events. As shown in Table II.1, the water level increase due to the Project headpond diminishes during the larger flood events.

Figures II.1 to II.5 present the water level exceedance curves (i.e. percent of time that the computed water level is expected to equalled or exceeded) at Stations 0+000, 4+095, 8+597, 15+985, and 26+000, respectively.

Table 3.9 Naturalized and Post-Bennett Dam River Flows

% Annual Exceedance and Annual Flood Events

Naturalized Peace River Flows (m3/s)

Post-Bennett Dam Peace River Flows

(m3/s) 100% 127 425 98% 195 619 95% 218 753 90% 250 902 80% 306 1,120 70% 395 1,290 60% 573 1,430 50% 822 1,540 40% 1,120 1,640 30% 1,580 1,750 20% 2,520 1,880 10% 4,130 2,150 5% 5,450 2,500 2% 6,690 3,020

Powerhouse Overtopping n.a. 3,380 1:2 Year Flood 7,490 3,680 1:5 Year Flood 9,120 4,920

1:10 Year Flood 10,200 5,750 1:20 Year Flood 11,300 6,540 1:50 Year Flood 12,700 7,570

0% 15,400 7,600 1:100 Year Flood 13,800 8,330 1:200 Year Flood 14,900 9,100 1:500 Year Flood 16,600 10,100

1:1000 Year Flood 17,800 10,900

Flow ConditionDischarge 5450 cms 2500 cms 2500 cms 822 cms 1540 cms 1540 cms 218 cms 753 cms 753 cms

River Station (m) Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project

Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project

Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project26+360 352.14 349.70 350.16 347.63 348.69 348.99 346.28 347.50 348.1126+240 352.11 349.67 350.14 347.60 348.66 348.97 346.25 347.47 348.0926+000 352.04 349.61 350.09 347.54 348.60 348.93 346.20 347.42 348.0718+239 349.63 347.18 349.01 344.89 346.07 348.22 343.21 344.74 347.7915+985 348.84 346.41 348.82 344.25 345.31 348.11 342.76 344.12 347.7611+691 347.60 345.05 348.63 342.81 343.92 348.01 341.41 342.69 347.738+597 346.73 344.15 348.54 341.73 342.95 347.97 339.91 341.58 347.724+095 345.74 343.27 348.47 340.91 342.09 347.94 339.17 340.77 347.710+599 344.49 342.37 348.40 340.29 341.31 347.90 338.84 340.17 347.700+280 344.51 342.36 348.40 340.27 341.29 347.91 338.82 340.15 347.700+000 344.48 342.33 348.40 340.24 341.26 347.91 338.81 340.13 347.70-0+060 344.47 342.32 342.32 340.23 341.25 341.25 338.81 340.12 340.12-0+120 344.47 342.31 342.31 340.23 341.25 341.25 338.80 340.12 340.12-0+351 344.36 342.20 342.20 340.06 341.11 341.11 338.57 339.95 339.95-0+771 344.14 341.85 341.85 339.64 340.68 340.68 338.30 339.53 339.53-1+431 343.88 341.57 341.57 339.49 340.46 340.46 338.26 339.39 339.39-2+141 343.69 341.39 341.39 339.36 340.27 340.27 338.20 339.27 339.27-2+270 343.66 341.36 341.36 339.35 340.24 340.24 338.20 339.25 339.25



Post Bennett

Dam

With Dunvegan

Project

Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project

Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project26+360 2.44 0.00 0.46 -1.06 0.00 0.31 -1.23 0.00 0.6126+240 2.44 0.00 0.47 -1.06 0.00 0.32 -1.22 0.00 0.6226+000 2.43 0.00 0.48 -1.06 0.00 0.33 -1.22 0.00 0.6518+239 2.45 0.00 1.83 -1.17 0.00 2.15 -1.53 0.00 3.0515+985 2.43 0.00 2.42 -1.06 0.00 2.80 -1.36 0.00 3.6411+691 2.55 0.00 3.59 -1.11 0.00 4.10 -1.29 0.00 5.048+597 2.58 0.00 4.39 -1.22 0.00 5.02 -1.67 0.00 6.134+095 2.47 0.00 5.20 -1.18 0.00 5.85 -1.60 0.00 6.940+599 2.12 0.00 6.03 -1.02 0.00 6.60 -1.34 0.00 7.530+280 2.15 0.00 6.04 -1.02 0.00 6.62 -1.33 0.00 7.550+000 2.15 0.00 6.07 -1.02 0.00 6.64 -1.32 0.00 7.57-0+060 2.16 0.00 0.00 -1.02 0.00 0.00 -1.32 0.00 0.00-0+120 2.16 0.00 0.00 -1.02 0.00 0.00 -1.32 0.00 0.00-0+351 2.16 0.00 0.00 -1.05 0.00 0.00 -1.38 0.00 0.00-0+771 2.29 0.00 0.00 -1.04 0.00 0.00 -1.24 0.00 0.00-1+431 2.31 0.00 0.00 -0.97 0.00 0.00 -1.14 0.00 0.00-2+141 2.29 0.00 0.00 -0.91 0.00 0.00 -1.07 0.00 0.00-2+270 2.29 0.00 0.00 -0.89 0.00 0.00 -1.06 0.00 0.00

95% Exceedance Flow

Summary of Modelled Peace River Water Surface ElevationsTable 3.10

5% Exceedance Flow 50% Exceedance Flow

5% Exceedance Flow 50% Exceedance Flow 95% Exceedance Flow

Table 3.11Summary of Modelled Peace River Water Surface Elevation Changes from Current Conditions



RiverHydraulicsResults wsel 101504.xls-Table 3.10&3.11 WL Comparison

MSA 200409Dunvegan Hydrology and Hydraulics


RiverHydraulicsResults wsel 101504.xls - Fig 3.15 WSEL 5% Chart

Figure 3.15Modelled Water Surface Profiles 5% Exceedance Flow

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-5+0000+0005+00010+00015+00020+00025+00030+000

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)

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5% Exceedance Flow 5450 cms Naturalized Flow

5% Exceedance Flow 2500 cms Post Bennett Dam

5% Exceedance Flow 2500 cms With Dunvegan Project

Invert Elevation (m)





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95% Exceedance Flow 753 cms With DunveganProjectInvert Elevation (m)


3.2.9.3 Velocities in the Headpond The calibrated HEC-RAS model was used to determine the average velocities within the headpond. Table 3.12 presents the modelled average velocities at each river cross-section within the headpond for the naturalized Peace River flows and the post-Bennett Dam river flows, with and without the Project. Table 3.13 presents a comparison of the changes in average velocity from the current flow regime (i.e. post-Bennett Dam flows) to naturalized flows (no regulation due to Bennett Dam) and post-Bennett Dam water levels with the Project. Figures 3.18 to 3.20 show the computed average velocity for the naturalized flows and post-Bennett Dam flows with and without the Project for the 5%, 50%, and 95% exceedance flows, respectively. Table II.2 presents the average channel velocity for the post-Bennett Dam flow regime, with and without the Project, and the naturalized flows at each surveyed river cross-section within the reach of river inundated by the Project. Table II.2 presents the average velocities for the 100% to 0% exceedance flows and the 1:2, 1:5, 1:10, 1:20, 1:50, 1:100, 1:200, 1:500, and 1:1000 year flood events. As shown in Table 3.13 and Figures 3.18 to 3.20, the most significant change in average velocity is immediately upstream of the Project where velocities are decreased by approximately 0.8 m/s during low flows and 1.2 m/s during flood flows. At Station 26+360, average velocities are approximately 0.2 m/s to 0.3 m/s lower with the Project than without.

3.2.9.4 Inundation As shown in Figures 3.15 to 3.17, the Project would form a headpond that would extend approximately 27 km upstream of the Project. The area inundated by the proposed Project was calculated for naturalized flows and post-Bennett Dam flows with and without the Project. The results are summarized in Table 3.14 which shows the change in water level, river volume, flooded area, and mean resident time for the post-Bennett flows with and without the Dunvegan Project. Figures 3.21 to 3.24 present the total effect of the Project on the inundated area and river volume within the headpond. Figures 3.21 and 3.22 present the increase in inundated area based on percent and area, respectively. Figures 3.23 and 3.24 present the increase in river volume in percent and volume, respectively.

Headpond volume and inundated area were determined using HEC-RAS output of flooded area and water top width at each surveyed river cross-section.

As shown in Table 3.14 and Figures 3.21 and 3.22, the increase in inundated area varies from 38% at the 100% exceedance flow to 2% during the 1:1000 year flood.

3.2.9.5 Headpond Volume The headpond volumes for a range of river flows are presented in Table 3.14 and Figures 3.23 and 3.24. For the 5%, 50%, and 95% exceedance flows, the increase in headpond volume is 80%, 120%, and 232%, respectively. For the 1:2 year flood the headpond volume is 73% greater than the existing regime diminishing to 34% for the 1:1000 year flood.



Post Bennett

Dam

With Dunvegan

Project

Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project

Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project26+360 2.26 1.71 1.54 1.12 1.40 1.27 0.71 1.09 0.8426+240 2.24 1.68 1.51 1.08 1.37 1.24 0.67 1.05 0.8126+000 2.22 1.66 1.49 1.06 1.35 1.22 0.64 1.03 0.7918+239 2.09 1.72 1.10 1.40 1.55 0.81 1.17 1.39 0.4415+985 2.25 1.70 1.04 1.05 1.41 0.72 0.54 1.01 0.3811+691 2.18 1.71 0.85 1.40 1.52 0.58 1.75 1.39 0.308+597 2.33 1.71 0.84 1.15 1.44 0.56 0.75 1.11 0.284+095 2.05 1.44 0.68 0.93 1.18 0.44 0.62 0.90 0.220+599 2.91 2.00 0.80 1.15 1.59 0.52 0.54 1.09 0.260+280 2.21 1.48 0.64 0.84 1.16 0.41 0.40 0.80 0.210+000 1.99 1.33 0.58 0.76 1.05 0.37 0.40 0.73 0.19-0+060 1.99 1.34 1.34 0.80 1.08 1.08 0.44 0.77 0.77-0+120 1.92 1.30 1.30 0.78 1.05 1.05 0.44 0.75 0.75-0+351 2.14 1.66 1.66 1.58 1.56 1.56 1.81 1.56 1.56-0+771 2.22 2.06 2.06 1.67 2.02 2.02 0.95 1.62 1.62-1+431 2.30 1.92 1.92 1.21 1.61 1.61 0.53 1.15 1.15-2+141 2.32 1.78 1.78 1.20 1.60 1.60 0.60 1.15 1.15-2+270 2.29 1.73 1.73 1.11 1.51 1.51 0.52 1.05 1.05

Flow ConditionDischarge 5450 2500 cms 2500 cms 822 cms 1540 cms 1540 cms 218 cms 753 cms 753 cms


Post Bennett

Dam

With Dunvegan

Project

Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project

Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project26+360 0.55 0.00 -0.17 -0.28 0.00 -0.13 -0.37 0.00 -0.2526+240 0.56 0.00 -0.17 -0.29 0.00 -0.12 -0.38 0.00 -0.2426+000 0.56 0.00 -0.18 -0.29 0.00 -0.13 -0.39 0.00 -0.2418+239 0.38 0.00 -0.62 -0.15 0.00 -0.74 -0.22 0.00 -0.9515+985 0.56 0.00 -0.66 -0.35 0.00 -0.69 -0.47 0.00 -0.6311+691 0.47 0.00 -0.85 -0.12 0.00 -0.94 0.35 0.00 -1.108+597 0.61 0.00 -0.87 -0.29 0.00 -0.88 -0.37 0.00 -0.834+095 0.61 0.00 -0.77 -0.25 0.00 -0.74 -0.28 0.00 -0.680+599 0.91 0.00 -1.20 -0.44 0.00 -1.07 -0.56 0.00 -0.830+280 0.73 0.00 -0.84 -0.33 0.00 -0.75 -0.39 0.00 -0.590+000 0.66 0.00 -0.75 -0.29 0.00 -0.68 -0.33 0.00 -0.54-0+060 0.64 0.00 0.00 -0.28 0.00 0.00 -0.32 0.00 0.00-0+120 0.62 0.00 0.00 -0.26 0.00 0.00 -0.31 0.00 0.00-0+351 0.48 0.00 0.00 0.03 0.00 0.00 0.25 0.00 0.00-0+771 0.17 0.00 0.00 -0.35 0.00 0.00 -0.67 0.00 0.00-1+431 0.38 0.00 0.00 -0.41 0.00 0.00 -0.62 0.00 0.00-2+141 0.55 0.00 0.00 -0.39 0.00 0.00 -0.55 0.00 0.00-2+270 0.57 0.00 0.00 -0.41 0.00 0.00 -0.54 0.00 0.00

95% Exceedance Flow

Summary of Modelled Peace River Mean Cross Section Flow Velocity (m/s)Table 3.12

5% Exceedance Flow 50% Exceedance Flow 95% Exceedance Flow

Table 3.13Summary of Modelled Peace River Mean Cross Section Flow Velocity Changes from Current Conditions (m/s)

5% Exceedance Flow 50% Exceedance Flow



RiverHydraulicsResults Velocities 101504.xls-Table 3.12&3.13 Vel Comparison



RiverHydraulicsResults Velocities 101504.xls - Fig 3.18 Vel 5% Chart

Figure 3.18Modelled Cross Section Velocity Profiles for 5% Exceedance Flow

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5% Exceedance Flow 2500 cms With DunveganProject





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50% Exceedance Flow 1540 cms With DunveganProject





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Table 3.14Comparison of Headpond Characteristics - Project Headpond vs. Current Regime

Project vs. Current Regime

Flow Event

Post-Bennett Discharge

(m3/s)

Water Level at Proposed Headworks

(m)

Headpond

Volume1

(dam3)

Mean Headpond Hydraulic Residence

Time (hours)

Headpond

Surface Area2

(ha)

Water Level at Headworks

(m)

Headpond

Volume1

(dam3)


Time (hours)

Headpond

Surface Area2

(ha)

Water Level at Headworks

(m)

Headpond Volume

(%)

Headpond Surface

Area

(%)


Time (hours)

100% 425 339.46 12,491 8.16 741 347.10 54,156 35.40 1,025 7.65 334% 38% 27.298% 619 339.87 16,048 7.20 796 347.50 58,514 26.26 1,036 7.63 265% 30% 19.195% 753 340.13 18,296 6.75 825 347.70 60,774 22.42 1,040 7.57 232% 26% 15.790% 905 340.39 20,710 6.36 856 347.90 63,081 19.36 1,044 7.51 205% 22% 13.080% 1,120 340.71 23,883 5.92 894 347.90 63,623 15.78 1,045 7.19 166% 17% 9.970% 1,290 340.93 26,220 5.65 918 347.90 64,096 13.80 1,047 6.97 144% 14% 8.260% 1,430 341.12 28,089 5.46 934 347.90 64,513 12.53 1,048 6.78 130% 12% 7.150% 1,540 341.26 29,502 5.32 946 347.91 64,859 11.70 1,049 6.64 120% 11% 6.440% 1,640 341.38 30,746 5.21 955 347.91 65,180 11.04 1,050 6.53 112% 10% 5.830% 1,750 341.53 32,092 5.09 962 347.91 65,542 10.40 1,051 6.38 104% 9% 5.320% 1,880 341.66 33,611 4.97 972 347.91 65,980 9.75 1,052 6.25 96% 8% 4.810% 2,150 341.93 36,651 4.74 989 348.40 71,287 9.21 1,082 6.47 95% 9% 4.55% 2,500 342.33 40,404 4.49 1,001 348.40 72,548 8.06 1,107 6.07 80% 11% 3.62% 3,020 342.87 45,696 4.20 1,021 348.40 74,409 6.84 1,112 5.54 63% 9% 2.60% 7,600 345.66 81,456 2.98 1,123 351.86 117,320 4.29 1,161 6.20 44% 3% 1.3

At Overtopping 3,380 343.14 48,996 4.03 1,030 348.40 75,756 6.23 1,116 5.26 55% 8% 2.21:2yr 3,680 343.36 51,648 3.90 1,039 349.86 89,285 6.74 1,134 6.50 73% 9% 2.81:5yr 4,920 344.17 62,220 3.51 1,102 350.57 99,081 5.59 1,141 6.40 59% 4% 2.11:10yr 5,750 344.66 68,531 3.31 1,110 350.99 105,004 5.07 1,147 6.33 53% 3% 1.81:20yr 6,540 345.10 74,240 3.15 1,117 351.38 110,475 4.69 1,153 6.28 49% 3% 1.51:50yr 7,570 345.65 81,257 2.98 1,123 351.85 117,161 4.30 1,161 6.21 44% 3% 1.3

1:100yr 8,330 346.03 86,208 2.87 1,127 352.18 121,874 4.06 1,163 6.15 41% 3% 1.21:200yr 9,100 346.41 91,019 2.78 1,130 352.50 126,465 3.86 1,165 6.09 39% 3% 1.11:500yr 10,100 346.88 97,037 2.67 1,135 352.92 132,377 3.64 1,166 6.04 36% 3% 1.01:1000yr 10,900 347.25 101,719 2.59 1,140 353.22 136,735 3.48 1,167 5.97 34% 2% 0.9

1 Headpond volumes based on cross sectional flow areas for given scenario. Areas assumed to vary linearly between sections.2 Headpond surface areas based on cross sectional top widths for given scenario. Topwidths assumed to vary linearly between sections.

Flow Condition Current Regime Post Project


1/16/0510:20 AMP:\Projects\MSA 2004\200409 Dunvegan Hydrology and Hydraulics\Hydrotechnical Repor

RiverHydraulicsResults Headpond 10152004.xls-Table 3.14 Headpond



RiverHydraulicsResults Headpond 10152004.xls - Fig 3.21 Areas (%)

Figure 3.21 Effect of Project Headpond on Inundated Areas (%)

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Inundated Area with ProjectInundated Area - Existing Regime% Increase in Inundated Area



RiverHydraulicsResults Headpond 022205.xls - Fig 3.22 Areas (ha)

Figure 3.22 Effect of Project Headpond on Inundated Areas (ha)

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RiverHydraulicsResults Headpond 022205.xls - Fig 3.23 Volumes (%)

Figure 3.23 Effect of Project Headpond on River Volume (%)

0

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iver

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ume

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RiverHydraulicsResults Headpond 022205.xls - Fig 3.24 Volumes (dam3)

Figure 3.24 Effect of Project Headpond on River Volume (dam3)

0

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er V

olum

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iver

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ume

(dam

3 )

River Volume with ProjectRiver Volume - Existing Regime% Increase in River Volume (dam3)


3.2.9.6 Mean Resident Time Mean resident time (i.e. travel time) is the time taken for water to travel through the headpond (Station 27+000 to Station 0+000). Table 3.14 shows the net effect that the headpond would have on the rate of water exchange. The increase in resident time, due to the headpond, is 15.7 hours, 6.4 hours, and 3.6 hours for the 95%, 50%, and 5% exceedance flows, respectively.

3.3 Screening Level Powerhouse and Spillway Structure Breach Inundation

3.3.1 General

Hydraulic simulations were completed to provide a preliminary or screening level analysis of the the extent, depth, velocity and timing of flood discharge which could result from a failure of the main powerhouse or spillway structure.

The preliminary analyses address fair weather failure conditions, rather than extreme loading or overtopping induced failures. Under fair weather conditions, breach development is sudden, occurring in response to a structural deficiency, seismic activity or some other unexpected cause, excluding excessive ice or flood loading from upstream.

Fair weather failures generally result in the greatest downstream incremental inundation, since the effect of the breach superimpose over relatively low, downstream flow and level conditions associated with typical river discharge. By contrast, overtopping failures normally involve much higher initial flooding, with greater river and/or floodplain width activated, so that the incremental stage increase due to breach discharge is less pronounced. Maximum incremental damages along any floodway do depend, however, in part, on the elevations of adjacent infrastructure or resources, and may not be associated with conditions that give the greatest increase in water level.

For this preliminary analysis, no attempt was made to identify a critical combination of initial discharge and breach conditions, or to quantify the maximum incremental damages. Instead, fair weather breach scenarios were simulated to provide conservative, upper estimates of the maximum potential water level rise. Further, since Project involves a relatively low height structure and one that is specifically designed to withstand overtopping up to the PMF, failure under flooding conditions may be much less probable than under fair weather scenarios.

As discussed below, based on the assessment of this preliminary analysis, more detailed risk assessment, hazard classification, and inundation mapping may be considered, along with a more detailed assessment of the scenarios resulting in maximum incremental damage, development of an Emergency Preparedness Plan (EPP) and Operation, Maintenance, and Surveillance (OMS) Manual.

3.3.2 Model Input Data

The United States National Weather Service (NWS) FLDWAV (v 2.0.0) model was used to simulate dam breach and downstream hydraulic river routing. The model numerically solves the continuity, energy and momentum equations of unsteady flow, facilitating evaluation of time-varying breach outflow to simulate impoundment failures. Key data inputs are summarized in Table 3.15.


It is noted that only two cross sections (aside from interpolated sections) were included between Station 10+000 and Station 102+000. Due to the relatively consistent geometry of the river valley, distance of the reach in question from the breach, and the scale of the river / valley geometry, this was considered suitable to the preliminary nature of the analyses.

Table 3.15 FLDWAV Breach Modelling Data Inputs

Input Source or Value

Headpond Stage Volume Relationship Table 4.7 - UMA Dunvegan Hydro Project Hydrology and Hydraulics Report, March 2000

Powerhouse Crest Elevation 348.4 m

Powerhouse Crest Width 213 m on south; 72.7 m on north river bank

Spillway Fixed Crest Elevation 344.4 m

Spillway Crest Elevation with Gate Up 347.9 m

Spillway Crest Width 100 m

Downstream Cross Section Geometry Sta. 0+000 to Sta. 5+321

Topwidth vs elevation based on combination of survey data collected by Skybase Surveying and Positioning Oct. 22, 2000, Nov. 3 2000, AENV 1987, and Glacier Power 1999.

Downstream Cross Section Geometry Sta. 5+321 to 102+000

1:50,000 NTS maps with 50 ft contour informationWSC stream gauging section at Peace River at Peace River gauging station Effective bed verified against reported thalweg elevations presented in "Hydraulic Flood Routing Models of the Peace and Slave Rivers, Hudson Hope to Great Slave Lake", Northern River Basins Study Project Report No. 77

Channel Roughness 0.025 - based on hydraulic analyses of the Peace River in the vicinity of the project site (see Section 3.1)

Steady state simulations (i.e. with constant river discharge) were undertaken prior to any failure analyses, to verify modelled levels against other hydrotechnical observations (WSC gauge records, surveyed levels) and modelling (steady state HECRAS modelling). Steady state water levels were verified to agree with previous level data to within 0.1 m, which was considered adequate given the preliminary nature of this assessment and highly dynamic breach response expected.

3.3.3 Dambreak Simulation

3.3.3.1 Failure Scenarios and Breach Parameters Table 3.16 summarizes the breach parameters employed for the four scenarios considered.


Table 3.16 Failure Scenario Parameters

Failure/Breach Parameters Scenario 1 Scenario 2 Scenario 3 Scenario 4

Failure occurs at: Powerhouse/ Spillway

Powerhouse orSpillway

Powerhouse or Spillway Spillway

Time to Complete Failure (min) 12, 60 12, 60 12, 60 6

Final Breach Width (m) 200 125 50 100

Proportion of Total Structure Breached 70% 44% 18% 100%

Lowest Breach Elevation (m) 336.5 336.5 336.5 344.4

Breach Side Slopes Vertical Vertical Vertical Vertical

Failure with Water Level at Elevation (m) 348.4 348.4 348.4 348.4

Initial Condition River Flow Rate (m3/s) 1,640 1,640 1,640 1,640

In all cases, failure was initiated at a water level equivalent to the top of powerhouse elevation of 348.4 m. This water level was presumed to develop following turbine shut-down with the spillway overshot gate operating in an attempt to maintain headpond level.

Flow within the river downstream of the facility (initial conditions discharge) was presumed to remain relatively close to 1,640 m3/s. A flow of 1640 m3/s corresponds to a discharge that is expected to be exceeded about 40% of the time (see Table 3.3).

Tributary inflows to the Peace River along the 102 km downstream study reach were neglected, providing for a more conservative representation of the water level increase due to the breach/failure. Moreover, tributary inflows under fair weather conditions are expected to be small, relative to increases in discharge due to the breach.

As shown in Table 3.16, a range of breach widths between 50 and 200 m were evaluated. Typically, concrete gravity embankments, like the proposed structure, would be expected to fail in sections, with individual monoliths separately yielding. Accordingly, widths up to 200 m would likely be considered highly conservative, since the data on observed and modelled breach width suggest observed values equal to roughly half of the structure (i.e. 125 m for the powerhouse and 50 m for the spillway). Since the Project structures are of relatively low height with individually stable monoliths (each 32 m wide), designed to withstand overtopping, widths of even 125 m is considered to be conservative.

Concrete gravity dams have also been observed to fail relatively quickly, with full breach width developing within about 0.2 hr (12 minutes). Due to the low height and overtopping design of the Project structures, a less rapid failure time could be expected. As such Scenarios 1, 2, and 3 were re-analyzed using a 1.0 hr breach width development time.

Scenario 4 evaluated the conditions following rapid (6 minute) failure of the overshot gates along the spillway ogee crest, with the spillway and main powerhouse structures remaining intact.


3.3.4 Results

3.3.4.1 General Tables 3.17 and 3.18 and Figures 3.25 to 3.29 illustrate computed maximum water level, maximum water depth, average velocity, peak flow rate, and time to peak flow rate for the four scenarios modelled, respectively. Table 3.17 summarizes the results at key river stations for the rapid (12 minute) powerhouse failure times while Table 3.18 summarizes results for 1 hour (60 minute) powerhouse failure simulations. The spillway overshot gate failure simulations are presented in both tables for comparison.

As shown in Tables 3.17 and 3.18, the larger breach width of 200 m results in the largest peak flow rates (varying from 11,000 m3/s immediately downstream of the Project diminishing to 9,320 m3/s at the Town of Dunvegan and 3,355 m3/s at the Town of Peace River), and greatest increase in downstream water levels (varying from 4.3 m immediately downstream of the Project diminishing to 3.8 m at the Town of Dunvegan and 1.5 m at the Town of Peace River).

The time to breach has little effect on the maximum water level rise downstream of the project. The shorter time to breach results in slightly higher peak flow rates (approximately 6% higher immediately downstream of the Project quickly diminishing to approximately 1% greater at the Town of Dunvegan) and faster time to peak flow (approximately 0.75 hours sooner at the Town of Dunvegan and 0.82 hours sooner at the Town of Peace River). For this level of study, the time to breach is not deemed to be significant.

The difference in peak flow rate, maximum downstream water level rise, and time to peak flow are significantly different depending on the presumed breach width within the powerhouse. As shown in Tables 3.17 and 3.18 and Figures 3.25 to 3.29, the peak flow rate immediately downstream of the Project varies from 3,511 m3/s for Scenario 3 (50 m breach width), 8,192 m3/s for Scenario 2 (125 m breach width), to 11,028 m3/s for Scenario 1 (200 m breach width). The maximum water level rise immediately downstream of the Project is 1.5 m, 3.5m, and 4.3 m for Scenarios 3, 2, and 1, respectively.

3.3.4.2 Town of Dunvegan and Highway 2 Bridge At the Town of Dunvegan, the peak flow rate is 3,187 m3/s, 7,138 m3/s, and 10,210 m3/s and a maximum water level increase of 1.4 m, 3.3 m, and 3.9 m for Scenarios 3, 2, and 1, respectively. A peak discharge of 3,187 m3/s corresponds to around the 1.5% to 2% annual exceedance flow at Dunvegan, while a peak discharge of 10,210 m3/s corresponds to the 1:500 year flood, approximately.


Table 3.17 Summary of Modelling Results – Rapid (12 min) Failure Time

Base Case Flow

1640 m3/s

Scenario 1 12 min Failure Time, 200 m Wide Breach



Scenario 4 6 min Failure Time,

Overshot Gate Failure

Station

Flow Rate

(m3/s)

Max. Depth

(m)

Peak Flow Rate

(m3/s)

Max Water Level Rise1 (m)

Max. Depth

(m)

Time of

Peak Flow(hr)

Peak Flow Rate

(m3/s)


Max. Depth

(m)

Time of

Peak Flow (hr)

Peak Flow Rate

(m3/s)


Max. Depth

(m)

Time of

Peak Flow(hr)

Peak Flow Rate

(m3/s))


Max. Depth

(m)

Time of

Peak Flow(hr)

Powerhouse 1,640 12.1 14,493 0.0 12.1 0.20 8,896 0.0 12.1 0.20 3,525 0.0 12.1 0.20 2,062 0.0 12.1 0.10

Station 0+500 1,640 5.3 13,889 4.4 9.7 0.22 8,437 3.5 8.8 0.22 3,407 1.5 6.8 0.40 2,029 0.4 5.7 0.29

Station 1+000 1,640 6.0 12,665 4.3 10.3 0.23 7,993 3.5 9.5 0.36 3,342 1.5 7.5 0.55 2,011 0.4 6.4 0.42

Station 2+200 Dunvegan Bridge 1,640 5.3 10,902 4.0 9.3 0.31 7,499 3.3 8.6 0.45 3,229 1.4 6.7 0.92 1,980 0.3 5.6 0.53

Station 3+000 (Dunvegan Settlement) 1,640 4.9 10,210 3.9 8.8 0.35 7,138 3.3 8.2 0.49 3,187 1.4 6.3 1.06 1,964 0.3 5.3 0.98

Station 5+000 1,640 5.4 8,588 3.6 9.1 0.49 6,541 3.1 8.5 0.70 3,121 1.3 6.7 1.40 1,947 0.3 5.8 1.39

Station 10+000 1,640 5.8 7,023 3.2 9.0 0.77 5,808 2.8 8.6 1.09 3,027 1.2 7.0 2.03 1,926 0.3 6.1 2.07

Station 82+000 (Shaftsbury Ferry) 1,640 4.6 3,670 2.0 6.6 7.11 3,488 1.9 6.5 7.64 2,600 1.1 5.7 10.11 1,831 0.2 4.8 10.63

Station 102+000 (Town of Peace River) 1,640 5.3 3,453 1.6 6.8 9.13 3,301 1.4 6.7 9.70 2,543 0.7 6.0 12.37 1,819 0.2 5.5 13.03

1. From 1640 m3/s Base Case.


Table 3.18 Summary of Modelling Results – Longer (60 min) Failure Time

Base Case Flow

1640 m3/s


200 m Wide





Station

Flow Rate

(m3/s)

Max. Depth

(m)

Peak Flow Rate

(m3/s)


Max. Depth

(m)

Time of

Peak Flow(hr)

Peak Flow Rate

(m3/s)


Max. Depth

(m)

Time of

Peak Flow (hr)

Peak Flow Rate

(m3/s)


Max. Depth

(m)

Time of

Peak Flow(hr)

Peak Flow Rate

(m3/s))


Max. Depth

(m)

Time of

Peak Flow(hr)

Powerhouse 1640 12.1 11028 0.0 12.1 1.00 8395 0.0 12.1 1.00 3511 0.0 12.1 1.00 2062 0.0 12.1 0.10

Station 0+500 1640 5.3 10837 4.3 9.6 1.00 8192 3.5 8.8 1.05 3427 1.5 6.8 1.05 2029 0.4 5.7 0.29

Station 1+000 1640 6.0 10444 4.3 10.3 1.00 7907 3.5 9.5 1.05 3351 1.5 7.5 1.25 2011 0.4 6.4 0.42

Station 2+200 (Dunvegan Bridge) 1640 5.3 9791 3.9 9.2 1.05 7368 3.3 8.6 1.10 3242 1.4 6.7 1.60 1980 0.3 5.6 0.53

Station 3+000 (Town of Dunvegan) 1640 4.9 9320 3.8 8.7 1.10 7073 3.2 8.1 1.15 3198 1.4 6.3 1.75 1964 0.3 5.3 0.98

Station 5+000 1640 5.4 8445 3.6 9.0 1.15 6489 3.1 8.5 1.35 3132 1.3 6.7 2.10 1947 0.3 5.8 1.39

Station 10+000 1640 5.8 6863 3.1 8.9 1.40 5753 2.8 8.5 1.75 3036 1.2 7.0 2.75 1926 0.3 6.1 2.07

Station 82+000 (Shaftsbury Ferry) 1640 4.6 3565 1.9 6.5 7.90 3442 1.8 6.4 8.35 2604 1.1 5.7 10.85 1831 0.2 4.8 10.63

Station 102+000 (Town of Peace River) 1640 5.3 3355 1.5 6.8 9.95 3258 1.4 6.7 10.45 2545 0.7 6.0 13.10 1819 0.2 5.5 13.03

1. From 1640 m3/s Base Case.



Prelim FLDWAV Results Figures 080304.xls-Fig 3.25 Water Surface Chart


Screening Level Dam Breach Results - Maximum Water Level

305

310

315

320

325

330

335

340

345

350

0 10 20 30 40 50 60 70 80 90 100

Station (km)

Elev

atio

n (m

)

Effective Invert Elevation

Max. Water Surface - 200 m Wide Breach




Initial Conditions Q=1640 m3/s

Tow

n of

Dun

vega

n km

3.0

Sha

ftesb

ury

Ferry

km

82

Tow

n of

Pea

ce R

iver

km

102

Dun

vega

n H

ydro

elec

tric

Pro

ject

km

0



Prelim FLDWAV Results Figures 080304.xls - Fig 3.26 Water Depth Chart


Screening Level Dam Breach Results - Maximum Water Depth

4

5

6

7

8

9

10

11

12

0 10 20 30 40 50 60 70 80 90 100

Station (km)

Dep

th (m

)

Max. Water Surface - 200 m Wide BreachMax. Water Surface - 125 m Wide BreachMax. Water Surface - 50 m Wide BreachOvershot Gate FailureInitial Conditions Q=1640 m3/s

Dunvegan Hydroelectric Project km 0

Tow

n of

Dun

vega

n km

3.0

Sha

ftesb

ury

Ferry

km

82

Tow

n of

Pea

ce R

iver

km

102



Prelim FLDWAV Results Figures 080304.xls - Fig 3.27 Velocity Chart


Screening Level Dam Breach Results - Average Velocity

0

1

2

3

4

5

6

0 10 20 30 40 50 60 70 80 90 100

Station (km)

Ave

rage

Cha

nnel

Vel

ocity

at P

eak

Dis

char

ge (m

/s)

Max. Water Surface - 200 m Wide BreachMax. Water Surface - 125 m Wide BreachMax. Water Surface - 50 m Wide BreachOvershot Gate Failure


Tow

n of

Dun

vega

n km

3.0

Sha

ftesb

ury

Ferry

km

82

Tow

n of

Pea

ce R

iver

km

102



Prelim FLDWAV Results Figures 080304.xls - Fig 3.28 Flow Rate Chart


Screening Level Dam Breach Results - Peak Flow Rate

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

0 10 20 30 40 50 60 70 80 90 100

Station (km)

Peak

Flo

w R

ate

(m3 /s

)

Max. Water Surface - 200 m Wide BreachMax. Water Surface - 125 m Wide BreachMax. Water Surface - 50 m Wide BreachOvershot Gate FailureInitial Conditions Q=1640 m3/s


Tow

n of

Dun

vega

n km

3.0

Sha

ftesb

ury

Ferry

km

82

Tow

n of

Pea

ce R

iver

km

102



Prelim FLDWAV Results Figures 080304.xls - Fig 3.29 Peak Time Chart


Screening Level Dam Breach Results - Time to Peak Discharge

0

2

4

6

8

10

12

14

0 10 20 30 40 50 60 70 80 90 100

Station (km)

Tim

e of

Pea

k Fl

ow R

ate

From

Bre

ach

(hrs

)





Dun

vega

n H

ydro

elec

tric

Pro

ject

km

0

Tow

n of

Dun

vega

n km

3.0

Sha

ftesb

ury

Ferry

km

82

Tow

n of

Pea

ce R

iver

km

102


The water level at the Town of Dunvegan at a peak discharge of 10,210 m3/s, based on the WSC 07FD003 (Peace River at Dunvegan) rating curve (see Figure 3.1), is approximately 347 m. This is significantly lower than the ground level within the Town of Dunvegan which is above elevation 350 m. Consequently, it appears that a possible structure breach (200 m wide) would not result in significant flooding within the Town of Dunvegan.

The elevation of the north and south Highway No. 2 abutments is approximately 358 m and 380 m, respectively. The low chord of the bridge appears to be significantly above the peak water level; however, there could be some impact on the bridge piers.

The time to peak flow varies from 0.35 hours for Scenario 1 to 1.06 hours for Scenario 3. Essentially, the time to peak discharge is very short at the Town of Dunvegan regardless of the presumed time to breach or breach width.

3.3.4.3 Town of Peace River At the Town of Peace River, the peak flow rate is 2,543 m3/s, 3,301 m3/s, and 3,453 m3/s with a maximum water level increase of 0.7 m, 1.4 m, and 1.6 m for Scenarios 3, 2, and 1, respectively. The time to peak flow varies from 9.1 hours for Scenario 1 to 12.4 hours for Scenario 3. The current 1:100 year flood peak discharge for the Peace River at the Town of Peace River is 23,700 m3/s (AENV pers comm. July 30, 2004), which is significantly larger than the predicted peak discharge of 3,453 m3/s for Scenario 3. Figure 3.30 presents the annual flow exceedance curve for the WSC gauge (WSC 07HA001) on the Peace River at the Town of Peace River. The flow exceedance curve is based on the recorded river flow recorded since Bennett Dam (1972 to 2003). As shown on Figure 3.30, a peak flow rate of 2,543 m3/s (Scenario 3) corresponds approximately to the 16% annual flow exceedance and a peak discharge of 3,453 m3/s (Scenario 1) corresponds to the 6% annual flow exceedance. Figure 3.31 presents the maximum daily discharge recorded at WSC 07HA001 post Bennett Dam (1972 to 2003). As shown in Figure 3.31, the recorded maximum daily discharge is greater than the maximum computed peak discharge of 3,453 m3/s (Scenario 1) for all years since 1972 except for 1995 and 1998. This would seem to indicate that existing infrastructure (i.e. houses, commercial buildings, roads, bridges, etc.) within the Town of Peace River are likely above, or protected from, the peak discharges that could occur due to a structure breach of the Project.

3.3.4.4 Spillway Gate Failure Scenario 4 presents the inundation that could occur if the spillway gates were to fail resulting in an uncontrolled flow release downstream. The resulting peak discharge immediately downstream of the Project is 2,062 m3/s, an increase of approximately 420 m3/s or 25% greater than the initial river discharge of 1,640 m3/s. A total spillway gate failure is not deemed to be significant since the increase in flow and maximum water level increase is well within the daily river flow and water level variation currently experienced within the Peace River.



TPR Annual Flow Exceedance 080304.xls - Fig 3.30 TPR Flow Exceedance

Figure 3.30Peace River at the Town of Peace River

Annual Flow Exceedance Curve

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

18,000

0 10 20 30 40 50 60 70 80 90 100

Percent of Time Flow Equalled or Exceeded

Dai

ly D

isch

arge

(m3 /s

)



TPR Annual Flow Exceedance 080304.xls - Fig 3.31 TPR Max Daily Q

Figure 3.31Peace River at Town of Peace River (WSC 07HA001)

Maximum Daily Discharge (1972 to 2003)

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

18,000

1972 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002

Year

Max

imum

Dai

ly D

isch

arge

(m3 /s

)


3.3.4.5 Summary of Screening Level Analysis The screening level dam breach inundation study identifies that a wide structure breach (200 m) could result in significantly increased flows downstream of the Project. This increased flow results in a maximum water level increase downstream of the Project of around 1.6 to 5.3 m; consequently, further dam breach inundation analyses may be warranted in further phases of design to assess the impact on downstream infrastructure (if any). Depending on these studies, a Project Emergency Preparedness Plan in the event of structure failure may be required.

4.0 CORPORATE AUTHORIZATION Mack, Slack & Associates Inc. has prepared this report entitled “Dunvegan Hydroelectric Project Hydraulics Report” dated August 2004.

Prepared by, Reviewed by,

Chuck Slack, P.Eng. Wes Dick, M.Sc., P.Eng. Principal Engineer Senior Water Resources Engineer

P:\Projects\MSA 2004\200409 Dunvegan Hydrology and Hydraulics\Hydrotechnical Report\R200409 Dunvegan Hydraulics Report 022205.doc

APPENDIX I

Monthly Operating Rule Curves

Table I.1Operating Rule Curve - January


River Discharge

Turbine Status

Tailwater Elevation

Headwater Elevation

Project Head

Number of Units

Operating

Power Flow

Powerhouse Overflow

Spillway Flow

Submerged Orifice

Fishways

Fishway Attraction

Flow - AWS

Upper-Level Fish

Sluices

Low-Level Fish

Sluices

(m3/s) (m) (m) (m) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s)100% 503 Operating 339.6 347.2 7.60 10 463 0 0 0 0 0 4098% 652 Operating 339.9 347.5 7.60 13 602 0 0 0 0 0 5095% 810 Operating 340.2 347.8 7.60 17 787 0 0 0 0 0 2390% 988 Operating 340.5 347.9 7.40 21 965 0 0 0 0 0 2380% 1,280 Operating 340.9 347.9 7.00 28 1,267 0 0 0 0 0 1370% 1,400 Operating 341.1 347.9 6.80 31 1,392 0 0 0 0 0 860% 1,510 Operating 341.2 347.9 6.70 33 1,476 0 0 0 0 0 3450% 1,560 Operating 341.3 347.9 6.60 35 1,559 0 0 0 0 0 140% 1,620 Operating 341.3 347.9 6.60 36 1,604 0 0 0 0 0 1630% 1,710 Operating 341.4 347.9 6.50 38 1,686 0 0 0 0 0 2420% 1,800 Operating 341.5 347.9 6.40 40 1,767 0 0 0 0 0 3310% 1,910 Operating 341.7 348.4 6.70 40 1,789 0 121 0 0 0 0

1:2 Year 1,929 Operating 341.7 348.4 6.70 40 1,789 0 140 0 0 0 05% 1,970 Operating 341.7 348.4 6.70 40 1,789 0 181 0 0 0 02% 2,090 Operating 341.8 348.4 6.60 40 1,782 0 308 0 0 0 0

1:5 Year 2,168 Operating 341.9 348.4 6.50 40 1,775 0 393 0 0 0 00% 2,260 Operating 342.0 348.4 6.40 40 1,767 0 493 0 0 0 0

1:10 Year 2,328 Operating 342.1 348.4 6.30 40 1,760 0 568 0 0 0 01:20 Year 2,488 Operating 342.2 348.4 6.20 40 1,752 0 736 0 0 0 01:50 Year 2,687 Operating 342.4 348.4 6.00 40 1,736 0 951 0 0 0 01:100 Year 2,837 Operating 342.6 348.4 5.80 40 1,721 0 1,116 0 0 0 01:200 Year 2,987 Operating 342.7 348.4 5.70 40 1,713 0 1,274 0 0 0 01:500 Year 3,187 Operating 342.8 348.4 5.60 40 1,706 0 1,481 0 0 0 01:1000 Year 3,336 Operating 343.0 348.4 5.40 40 1,691 0 1,600 0 0 0 45

Powerhouse Fish Sluices Lower Upper Spillway Gate Up Gate Down Note: Presumes open water conditions onlyC 1.8 C 0.6 0.98 C varies 1.6 2.0 (not accounting for ice effects)Width (m) 285.7 Size/Dia. 2.5x2.8 0.4 Width (m) 100Fixed Crest 348.4 Number 10 9 Fixed Crest 344.4

# Operating 0 0 Max. Gate Height (m) 3.5 3.5Invert El. 337 346

P:\Projects\MSA 2004\200409 Dunvegan Hydrology and Hydraulics\Hydrotechnical Report\Dunvegan Rule Curves msa 111704.xls11/18/04 Table I.1 Jan

Table I.2Operating Rule Curve - February

% Exceedance andFlood Events

River Discharge

Turbine Status

Tailwater Elevation

Headwater Elevation Project Head

Number of Units

Operating

Power Flow

Powerhouse Overflow

Spillway Flow

Submerged Orifice

Fishways

Fishway Attraction

Flow - AWS

Upper-Level Fish

Sluices

Low-Level Fish

Sluices

(m3/s) (m) (m) (m) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s)100% 478 Operating 339.6 347.2 7.60 10 463 0 0 0 0 0 1598% 638 Operating 339.9 347.5 7.60 13 602 0 0 0 0 0 3695% 781 Operating 340.2 347.8 7.60 16 741 0 0 0 0 0 4090% 946 Operating 340.4 347.9 7.50 20 923 0 0 0 0 0 2380% 1,160 Operating 340.8 347.9 7.10 25 1,136 0 0 0 0 0 2470% 1,310 Operating 341.0 347.9 6.90 29 1,307 0 0 0 0 0 360% 1,440 Operating 341.1 347.9 6.80 32 1,437 0 0 0 0 0 350% 1,570 Operating 341.3 347.9 6.60 35 1,559 0 0 0 0 0 1140% 1,650 Operating 341.4 347.9 6.50 37 1,641 0 0 0 0 0 930% 1,690 Operating 341.4 347.9 6.50 38 1,686 0 0 0 0 0 420% 1,780 Operating 341.5 347.9 6.35 40 1,763 0 0 0 0 0 17

1:2 Year 1,839 Operating 341.6 348.3 6.70 40 1,789 0 50 0 0 0 010% 1,870 Operating 341.6 348.4 6.80 40 1,796 0 74 0 0 0 05% 1,930 Operating 341.7 348.4 6.70 40 1,789 0 141 0 0 0 02% 2,000 Operating 341.8 348.4 6.60 40 1,782 0 218 0 0 0 0

1:5 Year 2,138 Operating 341.9 348.4 6.50 40 1,775 0 363 0 0 0 01:10 Year 2,338 Operating 342.1 348.4 6.30 40 1,760 0 578 0 0 0 01:20 Year 2,538 Operating 342.3 348.4 6.10 40 1,744 0 794 0 0 0 0

0% 2,640 Operating 342.4 348.4 6.00 40 1,736 0 904 0 0 0 01:50 Year 2,787 Operating 342.5 348.4 5.90 40 1,729 0 1,058 0 0 0 01:100 Year 2,977 Operating 342.7 348.4 5.70 40 1,713 0 1,264 0 0 0 01:200 Year 3,167 Operating 342.8 348.4 5.60 40 1,706 0 1,461 0 0 0 0

At Overtopping 3,380 Operating 343.0 348.4 5.40 40 1,691 0 1,600 0 0 0 89Overtopping 3,380 Shut-Down 343.0 349.7 6.67 0 0 736 2,420 0 0 0 2241:500 Year 3,406 Operating 343.0 349.7 6.69 0 0 753 2,433 0 0 0 219

1:1000 Year 3,596 Operating 343.2 349.8 6.61 0 0 861 2,517 0 0 0 218



P:\Projects\MSA 2004\200409 Dunvegan Hydrology and Hydraulics\Hydrotechnical Report\Dunvegan Rule Curves msa 111704.xls11/18/04 Table I.2 Feb

Table I.3Operating Rule Curve - March


River Discharge

Turbine Status

Tailwater Elevation


Number of Units

Operating

Power Flow

Powerhouse Overflow

Spillway Flow

Submerged Orifice

Fishways

Fishway Attraction

Flow - AWS

Upper-Level Fish

Sluices

Low-Level Fish

Sluices

(m3/s) (m) (m) (m) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s)100% 472 Operating 339.6 347.2 7.60 10 463 0 0 0 0 0 998% 541 Operating 339.7 347.3 7.60 11 509 0 0 0 0 0 3295% 700 Operating 340.0 347.6 7.60 15 695 0 0 0 0 0 590% 865 Operating 340.3 347.9 7.60 18 834 0 0 0 0 0 3180% 1,010 Operating 340.5 347.9 7.40 21 965 0 0 0 0 0 4570% 1,210 Operating 340.8 347.9 7.10 26 1,181 0 0 0 0 0 2960% 1,360 Operating 341.0 347.9 6.90 30 1,352 0 0 0 0 0 850% 1,450 Operating 341.1 347.9 6.80 32 1,437 0 0 0 0 0 1340% 1,520 Operating 341.2 347.9 6.70 33 1,476 0 0 0 0 0 4430% 1,600 Operating 341.3 347.9 6.60 35 1,559 0 0 0 0 0 4120% 1,680 Operating 341.4 347.9 6.50 37 1,641 0 0 0 0 0 39



1:10 Year 2,258 Operating 342.0 348.4 6.40 40 1,767 0 491 0 0 0 01:20 Year 2,468 Operating 342.2 348.4 6.20 40 1,752 0 716 0 0 0 01:50 Year 2,727 Operating 342.5 348.4 5.90 40 1,729 0 998 0 0 0 01:100 Year 2,927 Operating 342.6 348.4 5.80 40 1,721 0 1,206 0 0 0 01:200 Year 3,127 Operating 342.8 348.4 5.60 40 1,706 0 1,421 0 0 0 0

At Overtopping 3,380 Operating 343.0 348.4 5.40 40 1,691 0 1,600 0 0 0 89Overtopping 3,380 Shut-Down 343.0 349.7 6.67 0 0 736 2,420 0 0 0 2241:500 Year 3,386 Shut-Down 343.0 349.7 6.68 0 0 745 2,427 0 0 0 215

1:1000 Year 3,576 Shut-Down 343.2 349.8 6.60 0 0 852 2,510 0 0 0 214



P:\Projects\MSA 2004\200409 Dunvegan Hydrology and Hydraulics\Hydrotechnical Report\Dunvegan Rule Curves msa 111704.xls11/18/04 Table I.3 Mar

Table I.4Operating Rule Curve - April


River Discharge

Turbine Status

Tailwater Elevation


Number of Units

Operating

Power Flow

Powerhouse Overflow

Spillway Flow

Submerged Orifice

Fishways

Fishway Attraction

Flow

Upper-Level Fish

Sluices

Low-Level Fish

Sluices

(m3/s) (m) (m) (m) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s)100% 519 Operating 339.7 347.3 7.60 10 463 0 0 4 10 0 4298% 631 Operating 339.9 347.5 7.60 12 556 0 0 4 10 0 6195% 804 Operating 340.2 347.8 7.60 16 741 0 0 4 10 0 4990% 1,010 Operating 340.5 347.9 7.40 21 965 0 0 4 11 0 3080% 1,220 Operating 340.8 347.9 7.10 26 1,181 0 0 4 13 0 2270% 1,400 Operating 341.1 347.9 6.80 30 1,347 0 0 4 16 0 3360% 1,520 Operating 341.2 347.9 6.70 33 1,476 0 0 4 18 0 2250% 1,620 Operating 341.3 347.9 6.60 35 1,559 0 0 4 20 0 3740% 1,720 Operating 341.4 347.9 6.50 37 1,641 0 0 4 29 0 4630% 1,850 Operating 341.6 347.9 6.30 40 1,760 0 0 4 38 0 4820% 2,050 Operating 341.8 348.4 6.60 40 1,782 0 167 4 47 0 50


1:5 Year 3,087 Operating 342.8 348.4 5.60 40 1,706 0 1,227 4 60 0 902% 3,280 Operating 342.9 348.4 5.50 40 1,699 0 1,427 4 60 0 90

At Overtopping 3,380 Operating 343.0 348.4 5.40 40 1,691 0 1,535 4 60 0 90Overtopping 3,380 Shut-Down 343.0 349.7 6.68 0 0 745 2,427 0 0 0 2091:10 Year 3,546 Shut-Down 343.1 349.8 6.68 0 0 834 2,496 0 0 0 2171:20 Year 3,995 Shut-Down 343.5 350.1 6.55 0 0 1,090 2,686 0 0 0 2191:50 Year 4,565 Shut-Down 343.9 350.4 6.48 0 0 1,433 2,925 0 0 0 208

0% 4,440 Shut-Down 343.8 350.3 6.50 0 0 1,347 2,866 0 0 0 2271:100 Year 4,994 Shut-Down 344.2 350.6 6.41 0 0 1,690 3,095 0 0 0 2091:200 Year 5,413 Shut-Down 344.4 350.8 6.43 0 0 1,948 3,261 0 0 0 2041:500 Year 5,983 Shut-Down 344.8 351.1 6.31 0 0 2,294 3,476 0 0 0 212

1:1000 Year 6,402 Shut-Down 345.0 351.3 6.26 0 0 2,487 3,593 0 0 0 321



P:\Projects\MSA 2004\200409 Dunvegan Hydrology and Hydraulics\Hydrotechnical Report\Dunvegan Rule Curves msa 111704.xls11/18/04 Table I.4 Apr

Table I.5Operating Rule Curve - May


River Discharge Turbine Status Tailwater

ElevationHeadwater Elevation Project Head

Number of Units

Operating

Power Flow

Powerhouse Overflow

Spillway Flow

Submerged Orifice

Fishways

Fishway Attraction

Flow - AWS

Upper-Level Fish

Sluices

Low-Level Fish

Sluices

(m3/s) (m) (m) (m) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s)100% 670 Operating 340.0 347.6 7.60 13 602 0 0 4 10 0 5498% 811 Operating 340.2 347.8 7.60 16 741 0 0 4 10 0 5695% 965 Operating 340.5 347.9 7.40 20 919 0 0 4 10 0 3290% 1,240 Operating 340.9 347.9 7.00 26 1,177 0 0 4 11 0 4880% 1,480 Operating 341.2 347.9 6.70 32 1,431 0 0 4 13 0 3270% 1,640 Operating 341.4 347.9 6.50 36 1,597 0 0 4 16 0 2360% 1,760 Operating 341.5 347.9 6.40 38 1,679 0 0 4 18 0 5950% 1,900 Operating 341.6 348.3 6.70 40 1,789 0 57 4 20 0 3040% 2,030 Operating 341.8 348.4 6.60 40 1,782 0 175 4 29 0 4030% 2,180 Operating 341.9 348.4 6.50 40 1,775 0 313 4 38 0 5020% 2,390 Operating 342.1 348.4 6.30 40 1,760 0 519 4 47 0 6010% 2,670 Operating 342.4 348.4 6.00 40 1,736 0 804 4 56 0 70

1:2 Year 2,697 Operating 342.4 348.4 6.00 40 1,736 0 817 4 60 0 805% 2,980 Operating 342.7 348.4 5.70 40 1,713 0 1,113 4 60 0 90

1:5 Year 3,267 Operating 342.9 348.4 5.50 40 1,699 0 1,414 4 60 0 902% 3,350 Operating 343.0 348.4 5.40 40 1,691 0 1,505 4 60 0 90


0% 3,800 Shut-Down 343.3 349.9 6.64 0 0 983 2,608 0 0 0 2091:20 Year 4,005 Shut-Down 343.5 350.1 6.56 0 0 1,100 2,693 0 0 0 2121:50 Year 4,475 Shut-Down 343.8 350.3 6.52 0 0 1,368 2,881 0 0 0 2261:100 Year 4,824 Shut-Down 344.1 350.5 6.42 0 0 1,587 3,028 0 0 0 2091:200 Year 5,184 Shut-Down 344.3 350.7 6.41 0 0 1,806 3,170 0 0 0 2081:500 Year 5,643 Shut-Down 344.6 350.9 6.34 0 0 2,082 3,345 0 0 0 216

1:1000 Year 5,992 Shut-Down 344.8 351.1 6.32 0 0 2,307 3,484 0 0 0 201



P:\Projects\MSA 2004\200409 Dunvegan Hydrology and Hydraulics\Hydrotechnical Report\Dunvegan Rule Curves msa 111704.xls11/18/04 Table I.5 May

Table I.6Operating Rule Curve - June



ElevationHeadwater Elevation Project Head

Number of Units

Operating

Power Flow

Powerhouse Overflow

Spillway Flow

Submerged Orifice

Fishways

Fishway Attraction

Flow - AWS

Upper-Level Fish

Sluices

Low-Level Fish

Sluices


1:2 Year 3,177 Operating 342.8 348.4 5.60 40 1,706 0 1,317 4 60 0 90At Overtopping 3,380 Operating 343.0 348.4 5.40 40 1,691 0 1,535 4 60 0 90

Overtopping 3,380 Operating 343.0 349.7 6.68 40 0 745 2,427 0 0 0 2095% 3,500 Shut-Down 343.1 349.8 6.65 0 0 807 2,475 0 0 0 218

1:5 Year 4,385 Shut-Down 343.8 350.3 6.48 0 0 1,326 2,852 0 0 0 2082% 4,640 Shut-Down 343.9 350.4 6.52 0 0 1,476 2,954 0 0 0 209

1:10 Year 5,194 Shut-Down 344.3 350.7 6.41 0 0 1,806 3,170 0 0 0 2181:20 Year 5,963 Shut-Down 344.8 351.1 6.30 0 0 2,282 3,469 0 0 0 2131:50 Year 6,961 Shut-Down 345.3 351.6 6.27 0 0 2,902 3,840 0 0 0 219

0% 7,600 Shut-Down 345.7 351.9 6.16 0 0 3,310 4,075 0 0 0 2151:100 Year 7,710 Shut-Down 345.7 351.9 6.21 0 0 3,382 4,116 0 0 0 2121:200 Year 8,449 Shut-Down 346.1 352.2 6.13 0 0 3,855 4,382 0 0 0 2121:500 Year 9,437 Shut-Down 346.6 352.6 6.04 0 0 4,490 4,731 0 0 0 217

1:1000 Year 10,136 Shut-Down 346.9 352.9 6.02 0 0 4,942 4,974 0 0 0 220



P:\Projects\MSA 2004\200409 Dunvegan Hydrology and Hydraulics\Hydrotechnical Report\Dunvegan Rule Curves msa 111704.xls11/18/04 Table I.6 June

Table I.7Operating Rule Curve - July


River Discharge

Turbine Status

Tailwater Elevation


Number of Units

Operating

Power Flow

Powerhouse Overflow

Spillway Flow

Submerged Orifice

Fishways

Fishway Attraction

Flow - AWS

Upper-Level Fish

Sluices

Low-Level Fish

Sluices

(m3/s) (m) (m) (m) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s)100% 614 Operating 339.9 347.5 7.60 11 509 0 0 4 0 6 9598% 690 Operating 340.0 347.6 7.60 13 602 0 0 4 0 6 7895% 758 Operating 340.1 347.7 7.60 14 648 0 0 4 0 6 9990% 835 Operating 340.3 347.9 7.60 16 741 0 0 4 0 7 8380% 971 Operating 340.5 347.9 7.40 19 873 0 0 4 0 7 8770% 1,120 Operating 340.7 347.9 7.20 22 1,003 0 0 4 0 7 10660% 1,310 Operating 341.0 347.9 6.90 27 1,217 0 0 4 0 7 8250% 1,490 Operating 341.2 347.9 6.70 31 1,387 0 0 4 0 7 9340% 1,640 Operating 341.4 347.9 6.50 35 1,553 0 0 4 0 7 7630% 1,850 Operating 341.6 347.9 6.30 40 1,760 0 0 4 0 7 8020% 2,060 Operating 341.8 348.4 6.60 40 1,782 0 123 4 0 8 14310% 2,490 Operating 342.2 348.4 6.20 40 1,752 0 588 4 0 8 139


At Overtopping 3,380 Operating 343.0 348.4 5.40 40 1,691 0 1,547 4 0 8 130Overtopping 3,380 Shut-Down 343.0 349.7 6.67 0 0 736 2,420 0 0 0 224

1:5 Year 3,736 Shut-Down 343.3 349.9 6.60 0 0 945 2,580 0 0 0 2122% 4,280 Shut-Down 343.7 350.2 6.52 0 0 1,263 2,808 0 0 0 209

1:10 Year 4,485 Shut-Down 343.8 350.3 6.53 0 0 1,379 2,888 0 0 0 2181:20 Year 5,204 Shut-Down 344.3 350.7 6.42 0 0 1,817 3,178 0 0 0 209

0% 5,960 Shut-Down 344.8 351.1 6.30 0 0 2,282 3,469 0 0 0 2101:50 Year 6,132 Shut-Down 344.9 351.2 6.28 0 0 2,384 3,531 0 0 0 2171:100 Year 6,831 Shut-Down 345.3 351.5 6.21 0 0 2,820 3,792 0 0 0 2191:200 Year 7,520 Shut-Down 345.6 351.8 6.22 0 0 3,253 4,042 0 0 0 2251:500 Year 8,439 Shut-Down 346.1 352.2 6.12 0 0 3,840 4,374 0 0 0 226

1:1000 Year 9,128 Shut-Down 346.4 352.5 6.12 0 0 4,301 4,628 0 0 0 200



P:\Projects\MSA 2004\200409 Dunvegan Hydrology and Hydraulics\Hydrotechnical Report\Dunvegan Rule Curves msa 111704.xls11/18/04 Table I.7 July

Table I.8Operating Rule Curve - August


River Discharge

Turbine Status

Tailwater Elevation


Number of Units

Operating

Power Flow

Powerhouse Overflow

Spillway Flow

Submerged Orifice

Fishways

Fishway Attraction

Flow - AWS

Upper-Level Fish

Sluices

Low-Level Fish

Sluices

(m3/s) (m) (m) (m) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s)100% 445 Operating 339.5 347.1 7.60 8 371 0 0 4 0 5 6598% 534 Operating 339.7 347.3 7.60 10 463 0 0 4 0 6 6195% 588 Operating 339.8 347.4 7.60 11 509 0 0 4 0 6 6990% 646 Operating 339.9 347.5 7.60 12 556 0 0 4 0 6 8080% 793 Operating 340.2 347.8 7.60 15 695 0 0 4 0 7 8870% 906 Operating 340.4 347.9 7.50 18 830 0 0 4 0 7 6560% 1,040 Operating 340.6 347.9 7.30 21 961 0 0 4 0 7 6850% 1,190 Operating 340.8 347.9 7.10 24 1,090 0 0 4 0 7 8940% 1,330 Operating 341.0 347.9 6.90 27 1,217 0 0 4 0 7 10230% 1,450 Operating 341.1 347.9 6.80 30 1,347 0 0 4 0 7 9220% 1,580 Operating 341.3 347.9 6.60 33 1,470 0 0 4 0 7 9910% 1,780 Operating 341.5 347.9 6.40 38 1,679 0 0 4 0 7 90



At Overtopping 3,380 Operating 343.0 348.4 5.40 40 1,691 0 1,547 4 0 8 130Overtopping 3,380 Shut-Down 343.0 349.7 6.68 0 0 745 2,427 0 0 0 2091:10 Year 3,456 Shut-Down 343.1 349.7 6.62 40 0 780 2,454 0 0 0 2221:20 Year 4,065 Shut-Down 343.5 350.1 6.59 0 0 1,130 2,715 0 0 0 2211:50 Year 4,864 Shut-Down 344.1 350.5 6.44 0 0 1,610 3,043 0 0 0 2111:100 Year 5,463 Shut-Down 344.5 350.9 6.35 0 0 1,972 3,276 0 0 0 215

0% 5,740 Shut-Down 344.6 351.0 6.39 0 0 2,144 3,383 0 0 0 2131:200 Year 6,062 Shut-Down 344.8 351.2 6.35 0 0 2,345 3,507 0 0 0 2091:500 Year 6,851 Shut-Down 345.3 351.5 6.22 0 0 2,834 3,800 0 0 0 217

1:1000 Year 7,440 Shut-Down 345.6 351.8 6.19 0 0 3,210 4,018 0 0 0 212



P:\Projects\MSA 2004\200409 Dunvegan Hydrology and Hydraulics\Hydrotechnical Report\Dunvegan Rule Curves msa 111704.xls11/18/04 Table I.8 Aug

Table I.9Operating Rule Curve - September


River Discharge

Turbine Status

Tailwater Elevation


Number of Units

Operating

Power Flow

Powerhouse Overflow

Spillway Flow

Submerged Orifice

Fishways

Fishway Attraction

Flow - AWS

Upper-Level Fish

Sluices

Low-Level Fish

Sluices

(m3/s) (m) (m) (m) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s)100% 425 Operating 339.5 347.1 7.60 7 324 0 0 4 0 5 9298% 515 Operating 339.7 347.3 7.60 9 417 0 0 4 0 6 8995% 619 Operating 339.9 347.5 7.60 11 509 0 0 4 0 6 10090% 754 Operating 340.1 347.7 7.60 14 648 0 0 4 0 6 9580% 939 Operating 340.4 347.9 7.50 18 830 0 0 4 0 7 9870% 1,080 Operating 340.6 347.9 7.30 22 1,007 0 0 4 0 7 6260% 1,200 Operating 340.8 347.9 7.10 24 1,090 0 0 4 0 7 9950% 1,280 Operating 340.9 347.9 7.00 26 1,177 0 0 4 0 7 9340% 1,360 Operating 341.0 347.9 6.90 28 1,262 0 0 4 0 7 8730% 1,450 Operating 341.1 347.9 6.80 30 1,347 0 0 4 0 7 9220% 1,590 Operating 341.3 347.9 6.60 34 1,515 0 0 4 0 7 6510% 1,770 Operating 341.5 347.9 6.40 38 1,679 0 0 4 0 7 80



1:10 Year 2,438 Operating 342.2 348.4 6.20 40 1,752 0 536 4 0 8 1391:20 Year 2,687 Operating 342.4 348.4 6.00 40 1,736 0 802 4 0 8 1371:50 Year 3,017 Operating 342.7 348.4 5.70 40 1,713 0 1,159 4 0 8 133

0% 3,220 Operating 342.9 348.4 5.50 40 1,699 0 1,379 4 0 8 1311:100 Year 3,267 Operating 342.9 348.4 5.50 40 1,699 0 1,426 4 0 8 131

At Overtopping 3,380 Operating 343.0 348.4 5.40 40 1,691 0 1,547 4 0 8 130Overtopping 3,380 Shut-Down 343.0 349.7 6.67 0 0 736 2,420 0 0 0 2241:200 Year 3,506 Shut-Down 343.1 349.8 6.65 0 0 807 2,475 0 0 0 2241:500 Year 3,826 Shut-Down 343.4 350.0 6.55 0 0 992 2,615 0 0 0 219

1:1000 Year 4,075 Shut-Down 343.5 350.1 6.59 0 0 1,130 2,715 0 0 0 231



P:\Projects\MSA 2004\200409 Dunvegan Hydrology and Hydraulics\Hydrotechnical Report\Dunvegan Rule Curves msa 111704.xls11/18/04 Table I.9 Sept

Table I.10Operating Rule Curve - October


River Discharge

Turbine Status

Tailwater Elevation


Number of Units

Operating

Power Flow

Powerhouse Overflow

Spillway Flow

Submerged Orifice

Fishways

Fishway Attraction

Flow - AWS

Upper-Level Fish

Sluices

Low-Level Fish

Sluices

(m3/s) (m) (m) (m) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s)100% 561 Operating 339.8 347.4 7.60 10 463 0 0 4 0 6 8898% 777 Operating 340.2 347.8 7.60 15 695 0 0 4 0 7 7295% 915 Operating 340.4 347.9 7.50 18 830 0 0 4 0 7 7490% 1,050 Operating 340.6 347.9 7.30 21 961 0 0 4 0 7 7880% 1,170 Operating 340.8 347.9 7.10 24 1,090 0 0 4 0 7 6970% 1,270 Operating 340.9 347.9 7.00 26 1,177 0 0 4 0 7 8360% 1,380 Operating 341.0 347.9 6.90 29 1,307 0 0 4 0 7 6250% 1,450 Operating 341.1 347.9 6.80 30 1,347 0 0 4 0 7 9240% 1,510 Operating 341.2 347.9 6.70 32 1,431 0 0 4 0 7 6830% 1,580 Operating 341.3 347.9 6.60 33 1,470 0 0 4 0 7 9920% 1,680 Operating 341.4 347.9 6.50 36 1,597 0 0 4 0 7 7210% 1,840 Operating 341.6 347.9 6.30 40 1,760 0 0 4 0 7 70


1:5 Year 2,188 Operating 341.9 348.4 6.50 40 1,775 0 260 4 0 8 1421:10 Year 2,408 Operating 342.2 348.4 6.20 40 1,752 0 506 4 0 8 1391:20 Year 2,618 Operating 342.4 348.4 6.00 40 1,736 0 733 4 0 8 1371:50 Year 2,877 Operating 342.6 348.4 5.80 40 1,721 0 1,010 4 0 8 134

0% 3,000 Operating 342.7 348.4 5.70 40 1,713 0 1,142 4 0 8 1331:100 Year 3,077 Operating 342.8 348.4 5.60 40 1,706 0 1,227 4 0 8 1321:200 Year 3,277 Operating 342.9 348.4 5.50 40 1,699 0 1,436 4 0 8 131


1:1000 Year 3,736 Shut-Down 343.3 349.9 6.60 0 0 945 2,580 0 0 0 212



P:\Projects\MSA 2004\200409 Dunvegan Hydrology and Hydraulics\Hydrotechnical Report\Dunvegan Rule Curves msa 111704.xls11/18/04 Table I.10 Oct

Table I.11Operating Rule Curve - November



ElevationHeadwater Elevation

Project Head

Number of Units

Operating

Power Flow

Powerhouse Overflow

Spillway Flow

Submerged Orifice

Fishways

Fishway Attraction

Flow - AWS

Upper-Level Fish

Sluices

Low-Level Fish

Sluices




1:10 Year 2,308 Operating 342.1 348.4 6.30 40 1,760 0 548 0 0 0 01:20 Year 2,438 Operating 342.2 348.4 6.20 40 1,752 0 686 0 0 0 01:50 Year 2,598 Operating 342.3 348.4 6.10 40 1,744 0 854 0 0 0 01:100 Year 2,727 Operating 342.5 348.4 5.90 40 1,729 0 998 0 0 0 01:200 Year 2,857 Operating 342.6 348.4 5.80 40 1,721 0 1,136 0 0 0 01:500 Year 3,017 Operating 342.7 348.4 5.70 40 1,713 0 1,304 0 0 0 01:1000 Year 3,147 Operating 342.8 348.4 5.60 40 1,706 0 1,441 0 0 0 0



P:\Projects\MSA 2004\200409 Dunvegan Hydrology and Hydraulics\Hydrotechnical Report\Dunvegan Rule Curves msa 111704.xls11/18/04 Table I.11 Nov

Table I.12Operating Rule Curve - December


River Discharge

Turbine Status

Tailwater Elevation

Headwater Elevation

Project Head

Number of Units

Operating

Power Flow

Powerhouse Overflow

Spillway Flow

Submerged Orifice

Fishways

Fishway Attraction

Flow - AWS

Upper-Level Fish

Sluices

Low-Level Fish

Sluices



1:5 Year 2,208 Operating 342.0 348.4 6.40 40 1,767 0 441 0 0 0 01:10 Year 2,358 Operating 342.1 348.4 6.30 40 1,760 0 598 0 0 0 0

0% 2,490 Operating 342.2 348.4 6.20 40 1,752 0 738 0 0 0 01:20 Year 2,498 Operating 342.2 348.4 6.20 40 1,752 0 746 0 0 0 01:50 Year 2,687 Operating 342.4 348.4 6.00 40 1,736 0 951 0 0 0 0

1:100 Year 2,827 Operating 342.5 348.4 5.90 40 1,729 0 1,098 0 0 0 01:200 Year 2,967 Operating 342.7 348.4 5.70 40 1,713 0 1,254 0 0 0 01:500 Year 3,147 Operating 342.8 348.4 5.60 40 1,706 0 1,441 0 0 0 01:1000 Year 3,287 Operating 342.9 348.4 5.50 40 1,699 0 1,588 0 0 0 0



P:\Projects\MSA 2004\200409 Dunvegan Hydrology and Hydraulics\Hydrotechnical Report\Dunvegan Rule Curves msa 111704.xls11/18/04 Table I.12 Dec

APPENDIX II

Headpond Water Levels and Average Velocities

Table II.1Dunvegan Hydroelectric Project

Headpond Water Levels - Project, Existing, and Naturalized Flow Conditions

Water Surface Elevation Summary

Flow Event Naturalized Flow


Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project

Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project

Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project

Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project

(m3/s) (m3/s) (m) (m) (m) (m) (m) (m) (m) (m) (m) (m) (m) (m)100% 127 425 345.85 346.84 347.35 345.83 346.81 347.34 345.78 346.75 347.32 342.72 343.94 347.14

98% 195 619 346.19 347.24 347.84 346.17 347.21 347.83 346.12 347.15 347.81 343.10 344.44 347.57

95% 218 753 346.28 347.50 348.11 346.25 347.47 348.09 346.20 347.42 348.07 343.21 344.74 347.79

90% 250 905 346.41 347.77 348.38 346.38 347.75 348.37 346.33 347.69 348.34 343.35 345.05 348.02

80% 306 1,120 346.56 348.12 348.58 346.53 348.10 348.57 346.48 348.04 348.53 343.56 345.44 348.07

70% 395 1,290 346.77 348.36 348.75 346.74 348.33 348.73 346.68 348.28 348.69 343.85 345.70 348.13

60% 573 1,430 347.15 348.55 348.88 347.12 348.52 348.87 347.06 348.46 348.83 344.33 345.91 348.18

50% 822 1,540 347.63 348.69 348.99 347.60 348.66 348.97 347.54 348.60 348.93 344.89 346.07 348.22

40% 1,120 1,640 348.12 348.81 349.09 348.10 348.78 349.07 348.04 348.72 349.03 345.44 346.20 348.26

30% 1,580 1,750 348.73 348.93 349.20 348.71 348.90 349.18 348.65 348.85 349.14 346.12 346.34 348.30

20% 2,520 1,880 349.72 349.07 349.33 349.69 349.04 349.31 349.63 348.99 349.26 347.20 346.51 348.36

10% 4,130 2,150 351.14 349.36 349.80 351.11 349.33 349.78 351.04 349.27 349.74 348.61 346.83 348.86

5% 5,450 2,500 352.14 349.70 350.16 352.11 349.67 350.14 352.04 349.61 350.09 349.63 347.18 349.01

2% 6,690 3,020 352.87 350.20 350.59 352.84 350.16 350.56 352.77 350.10 350.51 350.45 347.68 349.24

At Overtopping 3,380 3,380 350.51 350.51 350.87 350.48 350.48 350.85 350.41 350.41 350.79 348.00 348.00 349.41

1:2yr 7,490 3,680 353.32 350.77 351.52 353.29 350.73 351.50 353.22 350.67 351.45 350.95 348.25 350.55

1:5yr 9,120 4,920 354.19 351.81 352.50 354.16 351.78 352.48 354.08 351.71 352.44 351.90 349.26 351.47

1:10yr 10,200 5,750 354.73 352.32 353.10 354.69 352.29 353.08 354.62 352.22 353.03 352.49 349.83 352.03

1:20yr 11,300 6,540 355.26 352.79 353.63 355.22 352.76 353.61 355.15 352.69 353.57 353.07 350.35 352.55

1:50yr 12,700 7,570 355.90 353.37 354.28 355.87 353.33 354.26 355.80 353.26 354.22 353.77 351.00 353.17

0% 15,400 7,600 357.09 353.38 354.30 357.06 353.35 354.28 356.98 353.28 354.23 355.04 351.01 353.19

1:100yr 13,800 8,330 356.40 353.78 354.74 356.36 353.74 354.71 356.29 353.67 354.67 354.30 351.45 353.61

1:200yr 14,900 9,100 356.88 354.18 355.18 356.84 354.15 355.15 356.77 354.07 355.11 354.81 351.89 354.04

1:500yr 16,600 10,100 357.59 354.68 355.73 357.56 354.65 355.71 357.49 354.57 355.66 355.58 352.43 354.59

1:1000yr 17,800 10,900 358.08 355.07 356.15 358.05 355.03 356.13 357.97 354.96 356.08 356.10 352.86 354.99

River Station (m) 26+360 26+240 26+000 18+239



RiverHydraulicsResults wsel 101504.xls-Table II.1 WSEL Summary






(m3/s) (m3/s)100% 127 425

98% 195 619

95% 218 753

90% 250 905

80% 306 1,120

70% 395 1,290

60% 573 1,430

50% 822 1,540

40% 1,120 1,640

30% 1,580 1,750

20% 2,520 1,880

10% 4,130 2,150

5% 5,450 2,500

2% 6,690 3,020

At Overtopping 3,380 3,380

1:2yr 7,490 3,680

1:5yr 9,120 4,920

1:10yr 10,200 5,750

1:20yr 11,300 6,540

1:50yr 12,700 7,570

0% 15,400 7,600

1:100yr 13,800 8,330

1:200yr 14,900 9,100

1:500yr 16,600 10,100

1:1000yr 17,800 10,900

River Station (m)

Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project

Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project

Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project

Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project

(m) (m) (m) (m) (m) (m) (m) (m) (m) (m) (m) (m)342.32 343.42 347.13 341.12 342.05 347.11 339.36 340.72 347.11 338.67 339.94 347.10342.66 343.86 347.54 341.31 342.44 347.52 339.79 341.29 347.51 339.05 340.47 347.51342.76 344.12 347.76 341.41 342.69 347.73 339.91 341.58 347.72 339.17 340.77 347.71342.88 344.39 347.98 341.53 342.96 347.94 340.06 341.89 347.92 339.30 341.07 347.91343.07 344.72 348.02 341.72 343.31 347.96 340.30 342.28 347.94 339.52 341.45 347.92343.35 344.97 348.05 341.98 343.58 347.98 340.63 342.57 347.95 339.84 341.71 347.92343.76 345.16 348.09 342.35 343.77 348.00 341.18 342.79 347.96 340.36 341.93 347.93344.25 345.31 348.11 342.81 343.92 348.01 341.73 342.95 347.97 340.91 342.09 347.94344.72 345.44 348.14 343.31 344.05 348.03 342.28 343.09 347.98 341.45 342.22 347.94345.36 345.57 348.17 343.97 344.19 348.05 343.01 343.24 347.99 342.14 342.38 347.95346.43 345.74 348.21 345.07 344.34 348.07 344.18 343.41 348.00 343.29 342.53 347.95347.85 346.05 348.72 346.57 344.66 348.57 345.71 343.74 348.51 344.78 342.85 348.45348.84 346.41 348.82 347.60 345.05 348.63 346.73 344.15 348.54 345.74 343.27 348.47349.68 346.91 348.99 348.47 345.58 348.73 347.58 344.72 348.61 346.56 343.84 348.50347.23 347.23 349.12 345.92 345.92 348.81 345.06 345.06 348.66 344.16 344.16 348.52350.18 347.49 350.36 348.98 346.19 350.16 348.08 345.33 350.05 347.04 344.42 349.95351.14 348.45 351.25 349.96 347.20 350.99 349.03 346.34 350.84 347.95 345.37 350.70351.73 349.05 351.79 350.56 347.82 351.50 349.62 346.95 351.32 348.51 345.95 351.15352.30 349.58 352.28 351.15 348.37 351.96 350.19 347.49 351.76 349.06 346.47 351.57353.00 350.23 352.88 351.85 349.03 352.53 350.87 348.13 352.29 349.72 347.09 352.07354.25 350.25 352.90 353.11 349.05 352.54 352.09 348.15 352.31 350.90 347.10 352.08353.52 350.69 353.31 352.37 349.50 352.93 351.38 348.58 352.67 350.22 347.52 352.43354.02 351.13 353.72 352.88 349.95 353.32 351.87 349.02 353.04 350.69 347.94 352.77354.77 351.67 354.24 353.64 350.50 353.82 352.60 349.56 353.51 351.40 348.46 353.22355.28 352.10 354.63 354.15 350.94 354.19 353.09 349.98 353.86 351.88 348.86 353.55

15+985 11+691 8+597 4+095









(m3/s) (m3/s)100% 127 425

98% 195 619

95% 218 753

90% 250 905

80% 306 1,120

70% 395 1,290

60% 573 1,430

50% 822 1,540

40% 1,120 1,640

30% 1,580 1,750

20% 2,520 1,880

10% 4,130 2,150

5% 5,450 2,500

2% 6,690 3,020


1:2yr 7,490 3,680

1:5yr 9,120 4,920

1:10yr 10,200 5,750

1:20yr 11,300 6,540

1:50yr 12,700 7,570

0% 15,400 7,600

1:100yr 13,800 8,330

1:200yr 14,900 9,100

1:500yr 16,600 10,100

1:1000yr 17,800 10,900

River Station (m)

Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project

Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project

Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project

Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project

(m) (m) (m) (m) (m) (m) (m) (m) (m) (m) (m) (m)338.41 339.49 347.10 338.40 339.47 347.10 338.39 339.46 347.10 338.39 339.45 339.45338.73 339.91 347.50 338.72 339.89 347.50 338.71 339.87 347.50 338.70 339.86 339.86338.84 340.17 347.70 338.82 340.15 347.70 338.81 340.13 347.70 338.81 340.12 340.12338.95 340.43 347.90 338.93 340.41 347.90 338.92 340.39 347.90 338.91 340.38 340.38339.13 340.76 347.90 339.11 340.74 347.90 339.09 340.71 347.90 339.09 340.70 340.70339.39 340.98 347.90 339.38 340.96 347.90 339.36 340.93 347.90 339.35 340.92 340.92339.82 341.17 347.90 339.80 341.15 347.90 339.78 341.12 347.90 339.77 341.11 341.11340.29 341.31 347.90 340.27 341.29 347.91 340.24 341.26 347.91 340.23 341.25 341.25340.76 341.43 347.91 340.74 341.41 347.91 340.71 341.38 347.91 340.70 341.37 341.37341.35 341.57 347.91 341.34 341.55 347.91 341.31 341.53 347.91 341.30 341.52 341.52342.39 341.70 347.91 342.38 341.68 347.91 342.35 341.66 347.91 342.34 341.65 341.65343.68 341.97 348.40 343.69 341.96 348.40 343.67 341.93 348.40 343.65 341.92 341.92344.49 342.37 348.40 344.51 342.36 348.40 344.48 342.33 348.40 344.47 342.32 342.32345.17 342.90 348.40 345.20 342.89 348.40 345.18 342.87 348.40 345.17 342.86 342.86343.17 343.17 348.40 343.17 343.17 348.40 343.14 343.14 348.40 343.13 343.13 343.13345.58 343.38 349.85 345.63 343.39 349.86 345.60 343.36 349.86 345.59 343.35 343.35346.37 344.18 350.56 346.44 344.19 350.57 346.42 344.17 350.57 346.41 344.16 344.16346.87 344.66 350.98 346.94 344.68 350.99 346.93 344.66 350.99 346.92 344.65 344.65347.35 345.09 351.36 347.44 345.12 351.38 347.42 345.10 351.38 347.42 345.09 345.09347.92 345.62 351.83 348.03 345.67 351.85 348.02 345.65 351.85 348.01 345.63 345.63348.96 345.64 351.84 349.09 345.68 351.86 349.10 345.66 351.86 349.09 345.65 345.65348.35 346.00 352.15 348.47 346.05 352.18 348.47 346.03 352.18 348.46 346.02 346.02348.77 346.37 352.47 348.90 346.43 352.50 348.91 346.41 352.50 348.90 346.40 346.40349.40 346.82 352.88 349.54 346.90 352.91 349.55 346.88 352.92 349.55 346.87 346.87349.82 347.18 353.18 349.98 347.26 353.21 350.00 347.25 353.22 349.99 347.24 347.24

0+599 0+280 0+000 -0+060






RiverHydraulicsResults wsel 022205.xls - Fig II.1 Sta 0 WSEL Excedance

Figure II.1Station 0+000 Annual (Jan-Dec) Water Level Exceedence Curves

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349

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%% of Time Water Surface Elevation is Equalled or Exceeded (%)

Wat

er S

urfa

ce E

leva

tion

(m)

Station 0+000 Naturalized Flow

0+000 Post Bennett Dam

0+000 With Dunvegan Project



RiverHydraulicsResults wsel 022205.xls - Fig II.2 Sta 4+095 WSEL Exc


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leva

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(m)

4+095 Naturalized Flow


4+095 With DunveganP j t





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0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

% of Time Water Surface Elevation is Equalled or Exceeded (%)

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urfa

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leva

tion

(m)








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Headpond - Flow Velocity Summary



Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project

Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project

Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project

Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project

(m3/s) (m3/s) (m/s) (m/s) (m/s) (m/s) (m/s) (m/s) (m/s) (m/s) (m/s) (m/s) (m/s) (m/s)100% 127 425 0.62 0.89 0.66 0.57 0.85 0.63 0.54 0.83 0.61 1.23 1.24 0.30

98% 195 619 0.69 1.02 0.77 0.64 0.98 0.74 0.62 0.96 0.72 1.17 1.34 0.38

95% 218 753 0.71 1.09 0.84 0.67 1.05 0.81 0.64 1.03 0.79 1.17 1.39 0.44

90% 250 905 0.73 1.15 0.91 0.69 1.12 0.88 0.66 1.10 0.86 1.17 1.43 0.50

80% 306 1,120 0.79 1.24 1.05 0.75 1.20 1.02 0.72 1.18 1.00 1.19 1.47 0.61

70% 395 1,290 0.87 1.31 1.15 0.83 1.27 1.12 0.80 1.25 1.10 1.22 1.51 0.69

60% 573 1,430 0.99 1.36 1.22 0.96 1.33 1.19 0.93 1.31 1.17 1.32 1.53 0.76

50% 822 1,540 1.12 1.40 1.27 1.08 1.37 1.24 1.06 1.35 1.22 1.40 1.55 0.81

40% 1,120 1,640 1.24 1.43 1.32 1.20 1.40 1.29 1.18 1.38 1.27 1.47 1.57 0.85

30% 1,580 1,750 1.41 1.47 1.36 1.38 1.44 1.33 1.36 1.42 1.31 1.56 1.59 0.90

20% 2,520 1,880 1.72 1.52 1.41 1.69 1.49 1.38 1.67 1.47 1.37 1.72 1.60 0.96

10% 4,130 2,150 2.06 1.61 1.43 2.03 1.58 1.41 2.02 1.56 1.39 1.98 1.65 0.98

5% 5,450 2,500 2.26 1.71 1.54 2.24 1.68 1.51 2.22 1.66 1.49 2.09 1.72 1.10

2% 6,690 3,020 2.47 1.84 1.69 2.45 1.81 1.66 2.44 1.80 1.64 2.20 1.81 1.26

At Overtopping 3,380 3,380 1.92 1.92 1.78 1.89 1.89 1.75 1.88 1.88 1.74 1.87 1.87 1.36

1:2yr 7,490 3,680 2.59 1.98 1.71 2.57 1.95 1.68 2.56 1.94 1.66 2.27 1.92 1.19

1:5yr 9,120 4,920 2.81 2.16 1.92 2.79 2.14 1.90 2.78 2.12 1.88 2.39 2.05 1.37

1:10yr 10,200 5,750 2.94 2.32 2.05 2.92 2.29 2.03 2.91 2.28 2.02 2.47 2.12 1.48

1:20yr 11,300 6,540 3.06 2.45 2.17 3.04 2.42 2.14 3.03 2.41 2.13 2.55 2.19 1.57

1:50yr 12,700 7,570 3.21 2.60 2.30 3.19 2.58 2.28 3.18 2.57 2.27 2.64 2.28 1.69

0% 15,400 7,600 3.47 2.61 2.31 3.44 2.58 2.29 3.44 2.57 2.27 2.80 2.28 1.69

1:100yr 13,800 8,330 3.32 2.71 2.40 3.30 2.68 2.38 3.29 2.67 2.36 2.71 2.33 1.76

1:200yr 14,900 9,100 3.42 2.81 2.49 3.40 2.78 2.47 3.39 2.77 2.45 2.77 2.39 1.84

1:500yr 16,600 10,100 3.57 2.93 2.60 3.55 2.91 2.58 3.54 2.90 2.57 2.87 2.47 1.92

1:1000yr 17,800 10,900 3.67 3.02 2.69 3.65 3.00 2.67 3.64 2.99 2.65 2.94 2.52 1.99

26+360 26+240 26+000 18+239River Station (m)



RiverHydraulicsResults wsel 101504.xls-Table II.2 Velocity Summary





(m3/s) (m3/s)100% 127 425

98% 195 619

95% 218 753

90% 250 905

80% 306 1,120

70% 395 1,290

60% 573 1,430

50% 822 1,540

40% 1,120 1,640

30% 1,580 1,750

20% 2,520 1,880

10% 4,130 2,150

5% 5,450 2,500

2% 6,690 3,020


1:2yr 7,490 3,680

1:5yr 9,120 4,920

1:10yr 10,200 5,750

1:20yr 11,300 6,540

1:50yr 12,700 7,570

0% 15,400 7,600

1:100yr 13,800 8,330

1:200yr 14,900 9,100

1:500yr 16,600 10,100

1:1000yr 17,800 10,900

River Station (m)

Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project

Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project

Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project

Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project

(m/s) (m/s) (m/s) (m/s) (m/s) (m/s) (m/s) (m/s) (m/s) (m/s) (m/s) (m/s)0.41 0.75 0.24 1.92 1.38 0.19 0.63 0.92 0.17 0.54 0.76 0.130.51 0.92 0.32 1.89 1.38 0.25 0.72 1.03 0.24 0.60 0.85 0.190.54 1.01 0.38 1.75 1.39 0.30 0.75 1.11 0.28 0.62 0.90 0.220.58 1.11 0.44 1.63 1.41 0.34 0.78 1.19 0.33 0.65 0.96 0.260.64 1.22 0.54 1.51 1.44 0.42 0.83 1.29 0.41 0.69 1.04 0.320.73 1.30 0.61 1.40 1.47 0.49 0.90 1.35 0.47 0.74 1.10 0.370.88 1.36 0.67 1.37 1.49 0.54 1.00 1.40 0.52 0.82 1.15 0.411.05 1.41 0.72 1.40 1.52 0.58 1.15 1.44 0.56 0.93 1.18 0.441.22 1.44 0.77 1.44 1.54 0.61 1.29 1.47 0.59 1.04 1.21 0.471.42 1.48 0.81 1.53 1.56 0.65 1.45 1.51 0.63 1.19 1.24 0.501.70 1.52 0.87 1.71 1.59 0.70 1.72 1.55 0.68 1.45 1.28 0.542.04 1.60 0.91 1.98 1.64 0.74 2.08 1.63 0.73 1.80 1.36 0.582.25 1.70 1.04 2.18 1.71 0.85 2.33 1.71 0.84 2.05 1.44 0.682.43 1.82 1.22 2.34 1.80 1.02 2.54 1.83 1.01 2.25 1.55 0.811.89 1.89 1.33 1.86 1.86 1.13 1.92 1.92 1.12 1.64 1.64 0.912.53 1.95 1.21 2.44 1.91 1.03 2.66 1.98 1.05 2.38 1.70 0.862.73 2.17 1.45 2.62 2.10 1.25 2.90 2.23 1.30 2.60 1.96 1.072.85 2.30 1.60 2.73 2.22 1.39 3.04 2.38 1.45 2.74 2.10 1.212.97 2.41 1.72 2.83 2.32 1.51 3.17 2.50 1.59 2.87 2.23 1.333.11 2.54 1.87 2.96 2.45 1.65 3.34 2.66 1.76 3.03 2.39 1.483.35 2.55 1.88 3.19 2.45 1.66 3.63 2.66 1.76 3.30 2.39 1.483.21 2.63 1.98 3.06 2.53 1.76 3.46 2.77 1.87 3.14 2.50 1.583.31 2.72 2.08 3.15 2.61 1.85 3.58 2.87 1.99 3.26 2.60 1.683.46 2.84 2.20 3.29 2.72 1.97 3.75 3.00 2.12 3.42 2.73 1.813.56 2.92 2.30 3.38 2.79 2.06 3.87 3.10 2.23 3.53 2.82 1.91

15+985 11+691 8+597 4+095








(m3/s) (m3/s)100% 127 425

98% 195 619

95% 218 753

90% 250 905

80% 306 1,120

70% 395 1,290

60% 573 1,430

50% 822 1,540

40% 1,120 1,640

30% 1,580 1,750

20% 2,520 1,880

10% 4,130 2,150

5% 5,450 2,500

2% 6,690 3,020


1:2yr 7,490 3,680

1:5yr 9,120 4,920

1:10yr 10,200 5,750

1:20yr 11,300 6,540

1:50yr 12,700 7,570

0% 15,400 7,600

1:100yr 13,800 8,330

1:200yr 14,900 9,100

1:500yr 16,600 10,100

1:1000yr 17,800 10,900

River Station (m)

Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project

Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project

Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project

Naturalized Flow

Post Bennett

Dam

With Dunvegan

Project

(m/s) (m/s) (m/s) (m/s) (m/s) (m/s) (m/s) (m/s) (m/s) (m/s) (m/s) (m/s)0.39 0.79 0.16 0.30 0.58 0.12 0.32 0.54 0.11 0.37 0.59 0.590.50 0.98 0.22 0.38 0.72 0.17 0.38 0.66 0.16 0.43 0.70 0.700.54 1.09 0.26 0.40 0.80 0.21 0.40 0.73 0.19 0.44 0.77 0.770.58 1.21 0.31 0.44 0.88 0.24 0.43 0.80 0.22 0.47 0.83 0.830.66 1.35 0.38 0.49 0.98 0.30 0.47 0.89 0.27 0.52 0.92 0.920.76 1.46 0.43 0.56 1.07 0.35 0.53 0.97 0.31 0.57 0.99 0.990.94 1.53 0.48 0.69 1.12 0.38 0.64 1.01 0.35 0.67 1.04 1.041.15 1.59 0.52 0.84 1.16 0.41 0.76 1.05 0.37 0.80 1.08 1.081.35 1.64 0.55 0.98 1.20 0.44 0.89 1.09 0.40 0.92 1.11 1.111.61 1.69 0.59 1.18 1.24 0.47 1.07 1.12 0.42 1.09 1.14 1.142.00 1.76 0.63 1.48 1.29 0.51 1.33 1.16 0.46 1.35 1.18 1.182.53 1.88 0.69 1.91 1.39 0.55 1.71 1.25 0.50 1.72 1.27 1.272.91 2.00 0.80 2.21 1.48 0.64 1.99 1.33 0.58 1.99 1.34 1.343.21 2.15 0.96 2.46 1.61 0.77 2.22 1.44 0.70 2.20 1.45 1.452.28 2.28 1.08 1.71 1.71 0.87 1.54 1.54 0.78 1.54 1.54 1.543.38 2.38 1.02 2.61 1.79 0.83 2.35 1.61 0.75 2.33 1.61 1.613.69 2.76 1.28 2.88 2.10 1.04 2.59 1.89 0.94 2.56 1.88 1.883.88 2.98 1.44 3.04 2.28 1.18 2.74 2.05 1.07 2.71 2.04 2.044.05 3.17 1.59 3.19 2.43 1.30 2.88 2.19 1.18 2.84 2.18 2.184.27 3.39 1.77 3.37 2.62 1.45 3.04 2.36 1.32 3.00 2.34 2.344.64 3.40 1.77 3.70 2.63 1.46 3.34 2.37 1.32 3.29 2.35 2.354.42 3.54 1.90 3.51 2.75 1.56 3.17 2.48 1.42 3.12 2.45 2.454.57 3.69 2.02 3.64 2.87 1.67 3.29 2.59 1.51 3.23 2.56 2.564.79 3.86 2.18 3.83 3.02 1.80 3.46 2.72 1.63 3.40 2.69 2.694.93 3.99 2.30 3.96 3.13 1.90 3.58 2.82 1.73 3.51 2.78 2.78

0+599 0+280 0+000 -0+060




r200409 dunvegan hydraulics report 022205 · r200409 dunvegan hydraulics report 022205.doc ....

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