Final Report for Alberta Utilities Commission Calgary, Alberta. Update on. Alberta's Hydroelectric Energy Resources

Transcription

1 Final Report for Alberta Utilities Commission Calgary, Alberta Update on Alberta's Hydroelectric Energy Resources H Rev. 1 February 26, 2010

2 Alberta Utilities Commission - Update on Alberta's Hydroelectric Energy Resources - February 26, 2010 Alberta Utilities Commission Update on Alberta's Hydroelectric Energy Resources Prepared by: January 28, 2010 LCB/JG/SM/BA Date Approvals Hatch Approved by: February 26, 2010 Lance Bendiak Date Alberta Utilities Commission Completed according to terms of reference: February 26, 2010 Don Popowich Date Distribution List Don Popowich - AUC ISO 9001 AUC Energy Study, Rev. 1, Page i Hatch 2010/02

3 Alberta Utilities Commission - Update on Alberta's Hydroelectric Energy Resources - February 26, 2010 PREFACE Hatch Ltd. (Hatch) was retained by the Alberta Utilities Commission to update the Energy Resources Conservation Board May 1981 Report, Alberta Hydroelectric Energy Resources, which was originally published in April While most of the basic information contained in 1981 report remains unchanged, the hydrologic data recorded and published since that time have been examined to determine their effect on the appraisal of hydroelectric resources. A few studies considering hydroelectric development were completed since that time. These recent studies have been considered in re-examining the underlying basis of the appraisal. ISO 9001 AUC Energy Study, Rev. 1, Page ii Hatch 2010/02

4 Alberta Utilities Commission - Update on Alberta's Hydroelectric Energy Resources - February 26, 2010 EXECUTIVE SUMMARY In Alberta there are five main river basins, the Athabasca, North Saskatchewan, Peace, Slave and South Saskatchewan. The ultimate hydroelectric energy potential that could be extracted from these river basins is about 53,000 gigawatt hours per year, or 42,000 gigawatt hours per year at identified sites. These figures refer to what might be developed under favourable economic and other circumstances over a long period into the future. Approximately 75 percent per of this ultimate potential is contained in the Athabasca, Peace and Slave River basins within the northern part of the province. The remaining 25 percent is in the Red Deer River basin and the North and South Saskatchewan River basins within the southern part of the province. Between 1911 and 1972, thirteen hydroelectric plants were completed in the Bow (a tributary of the South Saskatchewan) and North Saskatchewan River basins. These thirteen plants have a total installed capacity of 800 megawatts, operate at an average capacity factor of about 25 percent and produce about 3 percent of the total 53,000 gigawatt hours per year of ultimate potential. Since about 1990 another nine hydroelectric plants were completed in Southern Alberta with a combined capacity of about 100 megawatts. Their average capacity factor is about 45 percent and they produce about 1 percent of the ultimate potential of the province. Since publication of the original report in , various studies have been carried out for projects located on both northern and southern rivers. Northern projects have been examined for hydro electric potential, while southern projects have been examined for water supply purposes with supplementary investigation of the associated hydroelectric potential. The results of these studies have varied according to the type of project envisioned. In the early 1980 s there were studies completed for both the Dunvegan hydro project on the Peace River and Slave River hydro project. Although these projects appeared feasible they have not been developed further as large hydro projects. The Dunvegan site has recently been approved for a 100 MW low head run of river development which is not yet under construction. The Slave River hydro project has been looked at again recently by private developers. Basically, in the southern basins, hydroelectric plants appear feasible if the costs of dams and spillways are borne by some other water oriented purpose. This is the case for both the Dickson Dam and Oldman River Dam which have both had hydro facilities added after construction of the dams and spillways by Alberta Environment. 1 The Energy Resources Conservation Board April 1973 Report, The Hydro And Hydro Electric Energy Potential of Alberta - A Preliminarily Appraisal ISO 9001 AUC Energy Study, Rev. 1, Page iii Hatch 2010/02

5 Alberta Utilities Commission - Update on Alberta's Hydroelectric Energy Resources - February 26, 2010 Hatch believes that major projects in the northern basins and smaller projects in the southern basins may be developed in the next 30 years. Total development in this period might be as high as 20 percent of the province's ultimate potential of 53,000 gigawatt hours per year. However, to realize this capacity, 2 major projects would likely have to be constructed. If feasible, such development would serve the interests of energy conservation, reducing carbon emissions and providing renewable energy for the provincial electric system. ISO 9001 AUC Energy Study, Rev. 1, Page iv Hatch 2010/02

6 Alberta Utilities Commission - Update on Alberta's Hydroelectric Energy Resources - February 26, 2010 Table of Contents PREFACE... ii EXECUTIVE SUMMARY... iii Table of Contents... v List of Tables... vi List of Figures... vii 1. INTRODUCTION PHYSIOGRAPHY, CLIMATE AND HYDROLOGY PHYSIOGRAPHY CLIMATE HYDROLOGY TECHNICAL BASIS OF THE APPRAISAL DEFINITIONS AND ABBREVIATIONS DEFINITION OF ENERGY POTENTIALS Theoretical Maximum Hydroelectric Energy Potential (TMHE) Ultimate Developable Hydroelectric Energy Potential (UDHE) Developed Hydroelectric Energy (DHE) Remaining Developable Hydroelectric Energy Potential at Identified Sites (RDHE-I) Remaining Developable Hydroelectric Energy Potential at Unidentified Sites (RDHE-U) GROSS HEAD AND AVERAGE FLOW THE ATHABASCA RIVER BASIN GENERAL DESCRIPTION INVESTIGATIONS ENERGY POTENTIALS THE CHURCHILL RIVER BASIN GENERAL DESCRIPTION ENERGY POTENTIALS THE HAY RIVER BASIN GENERAL DESCRIPTION ENERGY POTENTIALS THE MILK RIVER BASIN GENERAL DESCRIPTION ENERGY POTENTIALS THE NORTH SASKATCHEWAN RIVER BASIN GENERAL DESCRIPTION INVESTIGATIONS AND DEVELOPMENT ENERGY POTENTIALS ISO 9001 AUC Energy Study, Rev. 1, Page v Hatch 2010/02

7 Alberta Utilities Commission - Update on Alberta's Hydroelectric Energy Resources - February 26, THE PEACE RIVER BASIN GENERAL DESCRIPTION INVESTIGATIONS ENERGY POTENTIALS THE RED DEER RIVER BASIN GENERAL DESCRIPTION ENERGY POTENTIALS THE SLAVE RIVER BASIN GENERAL DESCRIPTION INVESTIGATIONS ENERGY POTENTIALS THE SOUTH SASKATCHEWAN RIVER BASIN GENERAL DESCRIPTION INVESTIGATIONS AND DEVELOPMENT ENERGY POTENTIALS THE PROVINCE AS A WHOLE BIBLIOGRAPHY List of Tables 1 The Hydroelectric Energy Potential of the Athabasca River Basin 2 The Hydroelectric Energy Potential of the Churchill River Basin 3 The Hydroelectric Energy Potential of the Hay River Basin 4 The Hydroelectric Energy Potential of the Milk River Basin 5 The Hydroelectric Energy Potential of the North Saskatchewan River Basin 6 The Hydroelectric Energy Potential of the Peace River Basin 7 The Hydroelectric Energy Potential of the Red Deer River Basin 8 The Hydroelectric Energy Potential of the Slave River Basin 9 The Hydroelectric Energy Potential of the South Saskatchewan River Basin 10 The Hydroelectric Energy Potential of Alberta ISO 9001 AUC Energy Study, Rev. 1, Page vi Hatch 2010/02

8 Alberta Utilities Commission - Update on Alberta's Hydroelectric Energy Resources - February 26, 2010 List of Figures 1 Hydroelectric Capacity in Alberta 2 Alberta's Peak Load and Installed Capacity 3 Alberta River Basins 4 Alberta Bedrock Geology 5 Athabasca River Basin 6 Profile of the Athabasca River and its Major Tributaries 7 Average Flow - Drainage Area Relationships - Athabasca River Basin 8 Churchill River Basin 9 Profile of the Beaver River (Churchill River Basin) 10 Average Flow - Drainage Area Relationship - Beaver River (Churchill River Basin) 11 Hay River Basin 12 Profile of the Hay River 13 Average Flow - Drainage Area Relationship - Hay River Basin 14 Milk River Basin 15 Profile of the Milk River 16 Average Flow - Drainage Area Relationship - Milk River Basin 17 North Saskatchewan River Basin 18 Profile of the North Saskatchewan River and its Major Tributaries 19 Average Flow - Drainage Area Relationship - North Saskatchewan River Basin 20 Peace River Basin 21 Profile of the Peace River and its Major Tributaries 22 Average Flow - Drainage Area Relationships - Peace River Basin 23 Red Deer River Basin and its Major Tributaries 24 Profile of the Red Deer River 25 Average Flow - Drainage Area Relationship - Red Deer River Basin 26 Slave River Basin 27 Profile of the Slave River 28 South Saskatchewan River Basin 29 Profile of the South Saskatchewan River and its Major Tributaries 30 Average Flow - Drainage Area Relationships - South Saskatchewan River Basin ISO 9001 AUC Energy Study, Rev. 1, Page vii Hatch 2010/02

9 Alberta Utilities Commission - Update on Alberta's Hydroelectric Energy Resources - February 26, INTRODUCTION Hydroelectric development commenced in Alberta in 1896 with the construction of the Eau Claire plant at the end of the Eau Claire Sawmill log canal on the south side of Prince's Island in the City of Calgary. This plant had many problems with ice. For this reason and because of its small size and poor efficiency, it was later closed and removed. The earliest of the existing hydro plants commenced operating in 1911 when the Horseshoe Plant on the Bow River was commissioned to serve a cement plant located at Exshaw. This plant was subsequently connected to serve the City of Calgary. Since that time, 10 additional hydro plants have been built in the Bow River basin, 2 hydro plants on the North Saskatchewan River and 1 plant has been built in the Athabasca River basin. More recently there was 1 hydro plant built in the Red Deer River basin and 8 plants built in the South Saskatchewan River basin. The 1980 total installed capacity of the operating plants was 800 megawatts whereas in 2010 the capacity is about 900 megawatts. Figure 1 shows the historic sequence of hydro capacity additions. In the early years, hydroelectric plants were built as close as possible to the loads to be served. Recent technological advances in transmission and automation, the size of modern projects and the multi-purpose use of waters flowing through hydroelectric projects have altered the economic determining factors for developing hydroelectric plants. Presently, there is interest in developing hydroelectric plants at locations more remote from load centers. While hydro energy had played a significant role in Alberta and is still important, its role has been diminished in relative terms. In the early 1950 s, about half the province's installed capacity was hydroelectric. Currently the hydro capacity is about 7 percent of the total. This trend is shown in Figure 2. A number of rivers, either with headwaters in or flowing through Alberta, possess large hydro energy potential. Those rivers still undeveloped are mainly in the northern and sparsely settled part of the Province, whereas the rivers in the southern part of Alberta are substantially developed or already committed to other uses such as irrigation or municipal water supply. Studies and investigations dating as far back at 1916 have been undertaken from time to time by Government agencies and private companies on nearly all rivers of Alberta. Hatch presents an appraisal of the overall inventory and perspective of the hydroelectric energy resources in Alberta. Listed in the inventory are the theoretical hydro energy resources, the portion of that which considered potentially developable and the energy potential of known sites for which reports of previous investigations are available. Hatch also presents preliminary estimates of hydro energy which could be developed under favorable economic, environmental and social circumstances. However, Hatch does not propose to define the hydro energy which would actually be developed on any particular site or any particular river. The evaluation of any particular site for development must be based on detailed engineering and economic investigations and studies of ISO 9001 AUC Energy Study, Rev. 1, Page 1 Hatch 2010/02

10 Installed Capacity (MW) Time (Years) HYDRO ELECTRIC CAPACITY IN ALBERTA FIGURE 1

11 Net Capacity (MW) Time (Years) Hydro Wind Biomass & Other Thermal Peak Load FIGURE 2 ALBERTA'S PEAK LOAD AND INSTALLED CAPACITY

12 Alberta Utilities Commission - Update on Alberta's Hydroelectric Energy Resources - February 26, 2010 many factors which are beyond the scope of this appraisal. Hatch also recognizes that a complete evaluation of any potential hydroelectric development must have regard for multipurpose possibilities and for social and environmental impacts. In this report, consideration has been limited to the main rivers and the major tributaries of each of the nine river basins of the Province as identified in Figure 3. Minor tributaries have not been considered because of lack of adequate hydrologic and geotechnical data related to them. Notwithstanding the lack of relevant data, Hatch believes that the minor tributaries would make only a small contribution to the total hydro energy resources of the Province and recognizes that a small part of this additional potential may be developed in conjunction with other projects. The inventory is broadly based upon topographic information obtained from the National Topographic Series maps and stream flow data from Water Survey of Canada stream gauging stations. ISO 9001 AUC Energy Study, Rev. 1, Page 2 Hatch 2010/02

13 SASKATCHEWAN II I III IV V Map Legend Rivers VI Watershed Boundary Drainage Basins For purposes of this report the province is divided into basins as follows: VII X HAY I SLAVE II PEACE III ATHABASCA IV CHURCHILL V NORTH SASKATCHEWAN VI RED DEER VII SOUTH SASKATCHEWAN VIII MILK IX NON-CONTRIBUTING X BRITISH COLUMBIA VIII X IX km FIGURE 3 ALBERTA RIVER BASINS

14 Alberta Utilities Commission - Update on Alberta's Hydroelectric Energy Resources - February 26, PHYSIOGRAPHY, CLIMATE AND HYDROLOGY 2.1 PHYSIOGRAPHY Figure 4 presents the bedrock geology of the Province and shows Alberta comprised of four main divisions: the Canadian Shield in the northeast, the Interior plains region in the central and southeast, the Foothills in the south central region, and the Rocky Mountain Cordillera region covering the south-western portion of the Province. Each region is further divided into geologic periods where typical rock types are listed. The regions marked as undivided in the legend refer to areas where Geologic Periods cannot easily be differentiated. Rock types in these regions resemble a mixture of those in adjacent regions. The Rocky Mountains region is bounded by the Continental Divide on the west and by the most easterly ridge of the Rocky Mountains on the east. Local topography shows large elevation variations, from 1,200 metres in the large river valleys to over 3,000 metres at the mountain peaks. The sources of the Smoky, Athabasca, North Saskatchewan and South Saskatchewan rivers are in this region. The bedrock of the region is Paleozoic and Precambrian sedimentary rock consisting of limestone, dolomite, shale and quartzite. The valleys contain glacial gravel deposits, sometimes to great depths. In places, the mountains are capped by permanent snowfields and glaciers and the lower slopes are covered by alpine forests up to an elevation of about 2,100 metres. Paralleling the mountains and extending eastward from the eastern most ridge of the Rockies is the Foothills region, a transition zone between the Rocky Mountains and the Interior Plains regions. The characteristics of the transition zone are reflected in the vegetation. Alpine forest covers the higher elevations of the region and, as the elevation decreases, the vegetation changes to deciduous trees and finally to rolling grassland. The bedrocks of the region are Cretaceous, Jurassic, and Triassic formations composed of sandstone, shale, coal, carbonate rocks and gypsum. Rivers that originate in the mountains enter this zone at an elevation of about 1,200 metres and emerge on the plains at about 900 metres. A few rivers, such as the Berland, Nordegg and Little Red Deer Rivers originate in this region. The Interior Plains region is of low topographic relief, sloping gently eastward and northward, with poor drainage patterns and many small landlocked lakes, sloughs and marshes. Semi-arid conditions and "badlands" in the southeast part of the Province between the North and South Saskatchewan rivers change gradually to grassland, parkland, and bush country in the more moist central and northern parts of the plains. The soil deposited by the last continental glaciation is varied in texture and depth and mantles the bedrock by as much as 150 metres at some points. The bedrock beneath the plains may be generalized into four groups as shown in Figure 4. Eastward from the foothills are Tertiary sandstone, shale and coal; then Upper Cretaceous sandstone, shale, coal and bentonite. Further north is the Lower Cretaceous shale and the oil sands, and finally Devonian limestone, dolomite, shale and gypsum to the Canadian Shield. The flat or gently rolling topography of the plains is broken by a few ISO 9001 AUC Energy Study, Rev. 1, Page 3 Hatch 2010/02

15 SASKATCHEWAN MAP LEGEND BEDROCK GEOLOGY Geologic Period CANADIAN SHIELD Aphebian - Granite, Quartzite Helikian - Sandstone, Siltstone Archean - Granite, Gneiss, Quartzite INTERIOR PLAINS Cretaceous - Sandstone, Shale, Coal, Bentonite Devonian - Limestone, Dolomite, Salt, Gypsum FOOTHILLS Tertiary - Sandstone, Shale, Coal CORDILLERA Lower Paleozoic - Limestone, Dolomite, Shale, Quartzite Upper Paleozoic - Limestone, Dolomite, Shale Middle - Limestone, Dolomite, Shale OTHER Undivided BRITISH COLUMBIA km Source: Alberta Geological Survey ALBERTA BEDROCK GEOLOGY FIGURE 4

16 Alberta Utilities Commission - Update on Alberta's Hydroelectric Energy Resources - February 26, 2010 ridges of hills in which most of the small streams of the region have their source. Water yield from the plains is relatively low and in some areas almost negligible. The northeast corner of the Province is the Canadian Shield region, composed of hard Precambrian rocks which represent the roots of ancient mountains worn down through eons of time to a relatively level plain like surface. This Shield region is now characterized by numerous rounded and bare knobs of hard granite, gneiss and quartzite rocks, abundant angular lakes and marshy depressions, and an ineffective drainage system. Much of the land is lacking fine-grained surface material. The sparse vegetation is rooted in cracks in the rocks and only in a few sandy areas does jackpine exist in any abundance. No large streams originate in this region within Alberta, although minor streams provide drainage to the Slave River and Lake Athabasca. 2.2 CLIMATE Alberta is in the central belt of the northern cool temperate zone. It has cold winters and short, cool summers. Its climate is influenced by its latitude, altitude and distance from the ocean. Perhaps the most important factors affecting temperature and precipitation in Alberta are the height and width of the Rocky Mountains, and the direction of the prevailing winds which are from the west, southwest and northwest. The mean January temperature is -9 C in the most southern portion of the Province and decreases gradually to -23 C in the far northern parts. The mean temperature in July is about 16 C in the northern, central and south central part of the Province. It increases to about 20 C towards the southeast corner, and decreases to about 13 C in the mountain regions. The average annual precipitation of snow and rain is about 300 mm in the south eastern part of the Province, 460 mm in the central region and about 400 to 460 mm in the far northern area. Along the foothills and in the mountains precipitation ranges from 500 to 670 mm each year. 2.3 HYDROLOGY As shown in Figure 3, the Province is divided into nine river basins for the purpose of this appraisal. The Hay, Slave, Peace and Athabasca Rivers flow to the Arctic Ocean; the North Saskatchewan, Beaver (a tributary of the Churchill River), Red Deer and South Saskatchewan Rivers flow to the Hudson Bay; and a small area in the south is drained by the Milk River into the Missouri River system and the Gulf of Mexico. Almost all streams in the Province exhibit one general characteristic - stream flow begins to rise as the snowmelt season begins and, depending upon the incidence and intensity of rains, reaches an annual maximum during the months of May and June. Recession from the maximum usually continues through the rest of the summer and the succeeding winter with, however, significant differences between the various regions because of the variations in topography and in the timing and intensity of precipitation. ISO 9001 AUC Energy Study, Rev. 1, Page 4 Hatch 2010/02

17 Alberta Utilities Commission - Update on Alberta's Hydroelectric Energy Resources - February 26, 2010 On the plains, spring runoff from snowmelt begins in March or April and 80 percent or more of the total annual stream flow usually occurs in the next few weeks. In the Shield region, spring runoff is later than in the plains area further south. In the foothills, spring runoff occurs about the same time as on the plains, however, it tends to be prolonged as the warming trend gradually reaches the snow at higher elevations. The melt season in the region is closely followed by a rainy season and the streams do not recede from spring peaks but continue to rise and reach their maximum during periods of heavy precipitation in the early summer. Water yield is much higher in this region than in the plains and severe local floods may occur during the rainy season. In the mountain region, snowmelt starts later than in the plains and, while the streams originating in the plains are at their peak, the mountain streams may still be at their minimum flow. Spring thaw begins in the high snowfields in June and is completed in July. The rainy season usually begins in late May and peak flows are the result of the combination of rain and snowmelt anytime between late May and mid July. The July flows are also augmented by glacial melt, which tends to prolong the peak flows of summer. Almost all precipitation on the high snowfields is in the form of snow. Annual carry-over of snow accumulation in these areas depends on the summer temperatures. Winter flows on all rivers are affected by ice formation in winter. As the temperature drops below freezing, large quantities of ice are formed in the rivers. ISO 9001 AUC Energy Study, Rev. 1, Page 5 Hatch 2010/02

18 Alberta Utilities Commission - Update on Alberta's Hydroelectric Energy Resources - February 26, TECHNICAL BASIS OF THE APPRAISAL 3.1 DEFINITIONS AND ABBREVIATIONS Key definitions and abbreviations used in the energy assessment are listed below. Megawatt (MW) Gigawatt (GW) Gigawatt hour (GWh) Cubic metre per second (m 3 /s) Capacity Factor One million Watts One billion Watts One billion Watt hours a flow rate of one cubic metre of water passing a particular point in one second. the percentage of the actual output of a power plant over a year or other period of time and its output if it had operated at full capacity the entire time. 3.2 DEFINITION OF ENERGY POTENTIALS Estimates of the following energy potentials are made: Theoretical maximum hydroelectric energy potential (TMHE), gigawatt hours per year; Ultimate developable hydroelectric energy potential (UDHE), gigawatt hours per year; Developed hydroelectric energy (DHE), gigawatt hours per year; Remaining developable hydroelectric energy potential at sites which have been identified or studied (RDHE-I), gigawatt hours per year; and Remaining developable hydroelectric energy potential at unidentified sites (RDHE-U), gigawatt hours per year. Below is an illustration of the various energy potential definitions that have been used in this study to estimate the energies for the river basins and potential sites. The definitions and explanatory discussions of each of the energy terms follow the illustration. ISO 9001 AUC Energy Study, Rev. 1, Page 6 Hatch 2010/02

19 Alberta Utilities Commission - Update on Alberta's Hydroelectric Energy Resources - February 26, Theoretical Maximum Hydroelectric Energy Potential (TMHE) This is the maximum electric energy which could be generated during a year if all the flowing water were passed through turbines to generate electric energy. The conversion efficiency, which accounts for reservoir drawdown, unavoidable spill, and conduit, turbine and generation losses, has been estimated to be 70 percent. This percentage is 10 percent lower than in the previous studies because it provides better estimates of energy generation which are more in line with existing and anticipated hydroelectric developments. It has been based on a comparison of the actual generation at existing plants versus the value predicted with Equation 1. Therefore, the theoretical maximum hydroelectric energy (TMHE) which could be generated during a year is given by the following formula: TMHE = Q H (GWh per year) (Equation 1) where Q = the average flow in the reach during the year in cubic metres per second (m 3 /s), H = the gross head or elevation change over the reach in metres. ISO 9001 AUC Energy Study, Rev. 1, Page 7 Hatch 2010/02

20 Alberta Utilities Commission - Update on Alberta's Hydroelectric Energy Resources - February 26, Ultimate Developable Hydroelectric Energy Potential (UDHE) A certain portion of the theoretical maximum hydroelectric energy potential cannot be considered to be practically developable under any foreseeable technology or economic condition because of the nature of the river gradient and the elevation of the banks and the surrounding land; the lack of suitable sites; major social or environmental restriction - national parks, historical or archaeological treasures, urban development; other water uses such as irrigation; and other similar factors. For these reasons, the ultimate developable hydroelectric energy (UDHE) potential will in most cases be substantially less than the theoretical maximum hydroelectric energy potential. In this appraisal, the UDHE is determined by reducing the TMHE through the application of broad judgment based upon a general assessment of the above listed factors. The fraction of the TMHE which were considered to be developable under any such foreseeable circumstances varies for individual rivers, or for individual reaches of a river, from 0 to 90 percent. For the Province as a whole, the fraction of the theoretical hydro electric potential which could be considered developable under favourable economic and other circumstances is estimated at about 50 percent Developed Hydroelectric Energy (DHE). This is the portion of the ultimate developable hydroelectric energy (UDHE) potential which is already developed Remaining Developable Hydroelectric Energy Potential at Identified Sites (RDHE-I) The further portion of the developable hydroelectric energy, which could be developed at sites studied or identified by past investigations, is designated RDHE-I. The identified sites include those investigated for irrigation, water supply, flood control and the regulation of river flow in addition to those investigated for hydro energy potential. The hydroelectric energy potential of such sites has been calculated using equation 1. The stream flow of any river in Alberta is far from uniform and varies not only on an irregular annual cycle but also from day to day and month to month. For example, the Athabasca River records show that the river at the Town of Athabasca receded to a minimum monthly flow of 50 m 3 /s in February of 1923, reached a maximum monthly flow of 2,500 m 3 /s in May of 1948, and has a long term average flow of 417 m 3 /s. Such records of wide variations in actual rivers flows show that without an appropriate combination of onsite and upstream reservoir storage, plus ample installed generating capacity at each site, the developable energy at any identified site will be less than the ultimate values tabulated in this report. ISO 9001 AUC Energy Study, Rev. 1, Page 8 Hatch 2010/02

21 Alberta Utilities Commission - Update on Alberta's Hydroelectric Energy Resources - February 26, Remaining Developable Hydroelectric Energy Potential at Unidentified Sites (RDHE-U) The remaining developable hydroelectric energy potential at unidentified sites is the ultimate potential (UDHE) less the developed potential (DHE) and less the identified developable potential (RDHE-I). The estimates of the RDHE-U reflect the same broad judgment referred to in the identification of the ultimate potential (UDHE). On a few river reaches where identified sites are overlapping each other the largest developable site has been used to develop totals for that river reach. 3.3 GROSS HEAD AND AVERAGE FLOW All energy calculations are based upon the gross head and the annual average stream flow. In this appraisal, the gross head or elevation change has in every instance been taken as the difference between head pond or reservoir full supply level and the tailwater level below a hydro site or plant at average flow. Stream gauging stations having long term records exist at several points along most rivers but the locations of the gauging stations rarely coincide with specific points of interest. Average annual flow estimates of individual river reaches or at identified sites are based on regional regressions of the available stream gauging records to the applicable drainage area. The technique is illustrated in Figure 7, Section 4. An important part of updating the estimation of hydroelectric energy potential is the re-examination of the hydrologic record to determine whether the previous estimates of average flows should be revised in light of the additional hydrologic records available. Water Survey of Canada publishes stream flow data annually. At the time of the last report, stream flow data to 1978 was used to estimate average flows. At the time of writing of this report, data were available to Mean flows incorporating all data to 2008 were compared to the flow reported in the previous report. It is worth noting that in the updating of the hydrology from the 1981 version, it was observed in the hydrometric data that rivers have shown a general reduction in recorded flows. Although some of this reduction can be attributed to new irrigation and industrial uses, this province wide trend suggests that annual rainfall accumulations are declining in Alberta and it is a dryer region than previously observed. While it is not certain, the trends observed are based on significantly more years of record and have therefore been used for the present analysis of hydroelectric potential. ISO 9001 AUC Energy Study, Rev. 1, Page 9 Hatch 2010/02

22 Alberta Utilities Commission - Update on Alberta's Hydroelectric Energy Resources - February 26, THE ATHABASCA RIVER BASIN 4.1 GENERAL DESCRIPTION The Athabasca River, one of the larger rivers in Alberta, is the most southerly of the major tributaries of the MacKenzie River. The major tributaries of the Athabasca considered in this appraisal are the Berland, Wildhay, McLeod, Pembina and Clearwater Rivers. The Athabasca River has its source in the Rocky Mountains area near Mt. Columbia. It flows through most of the different geological formations to be found in the Province and, after following a north-easterly and northerly course for slightly less than km, empties into Lake Athabasca. From there its waters are conveyed by the Slave River to Great Slave Lake and from there to the Arctic Ocean by the MacKenzie River. Figures 5 and 6 show the plan and profile of the Athabasca basin. In its upper reaches, the river valley has low banks, increasing in height from Hinton to Whitecourt. From Whitecourt to Fort McMurray, the valley is deep with a gradual tapering from there to Lake Athabasca. The average flow of the river at the Town of Athabasca is 417 m 3 /s. The maximum monthly recorded flow at Athabasca is 2,500 m 3 /s, the minimum recorded monthly flow is 50 m 3 /s. Lakes in the upper reaches of the drainage basin tend to regulate the flow and spring floods are not so prominent as in most mountain and foothills streams. However, flood conditions can occur, and the most likely period is the latter part of June and early July. The maximum daily flow at Athabasca was recorded as 5,440 m 3 /s on June 10, INVESTIGATIONS Until 1951, the Athabasca River was considered to be the most favourable river for power development after the Bow River. Closer examinations in the early 1950's by the Alberta Power Commission and Calgary Power Ltd. (currently known as TransAlta) indicated certain advantages to developing the North Saskatchewan River. For the purposes of assessment of the energy potentials, the Athabasca River is divided into four reaches starting with Reach A from the source at the Columbia Glacier to Hinton; Reach B extending from Hinton to just above the mouth of the Pembina, at approximately Vega; Reach C extending from Vega to Fort McMurray; and Reach D from Fort McMurray to Lake Athabasca. Reach A, from the Columbia Glacier to Hinton, is almost entirely within the Jasper National Park and has a fall of approximately 550 metres in a distance of 215 km. This is an extremely large drop but on examination it would appear that good natural development sites are not present. On examining the old reports prepared by the Commission of Conservation Canada, the only sites considered were at Jasper Lake and at Brule Lake, both of which have limited storage and head and would result in difficulties with both the existing railway and the highway. When permission was requested in the early 1950's to examine the Maligne and Snake Indian Rivers, it was refused by the Parks Department of the Federal Government. The only development is a small hydro plant on the Astoria ISO 9001 AUC Energy Study, Rev. 1, Page 10 Hatch 2010/02

23 Athabasca River SASKATCHEWAN Moberly Rapids Site Crooked Rapids Site Fort McMurray Clearwater River Brule Point Site Whitemud Falls Site Grand Rapids Site Pelican Rapids Site Lesser Slave Lake Moose Portage Site Mirror Site Athabasca Pinto Creek Site Labyrinth Site Berland Site Berland River Wildhay River Hinton Oldman Site Edson McLeod River Image Rock Site Whitecourt Athabasca River Pembina River Vega McLeod Site Pembina Site McLeod Valley Site BRITISH COLUMBIA Jasper Astoria Hydro Athabasca River km ATHABASCA RIVER BASIN FIGURE 5

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25 Alberta Utilities Commission - Update on Alberta's Hydroelectric Energy Resources - February 26, 2010 River, a minor tributary upstream of Jasper. This plant has a total capacity of 1.4 megawatts operating at a head of 152 metres. Reach B from Hinton to Vega just above the mouth of the Pembina has a fall of approximately 380 metres. This reach was given a cursory examination many years ago by the Commission of Conservation Canada and private consultants but was not considered attractive for early development. Early in the 1950's the same area was given another preliminary examination by the Alberta Power Commission and Calgary Power Ltd., and again was discarded due to the magnitude of the possible developments and the topographical and geological problems. The Alberta Water Resources Division has also examined this reach from Hinton to the mouth of the Berland River. Some potential should be placed on the sites within the reach but even with multi-purpose use the developments do not appear very attractive at this time. The confluence of both the Berland and McLeod Rivers with the Athabasca occurs in reach B. The Berland is a relatively low flow tributary and foundation examination, although preliminary, indicates difficult construction problems. The average flow is approximately 43 m 3 /s and the amount of the potential energy is not significant in terms of present energy requirements. The McLeod River, with an average flow of 53 m 3 /s, may have slightly more potential. Reach C from Vega to Fort McMurray, has a fall of approximately 365 metres in 600 km and appears to be the most attractive reach from the standpoint of power development. Sites have been located in the past and one has had preliminary drilling. This section may also benefit from the large storage at Lesser Slave Lake, which discharges into the main river through the Lesser Slave River above the most upstream site in the reach. It appears that storage created by the Mirror site (see Figure 5) would drown out any sites on the Lesser Slave River. In 1975, a study of the Crooked Rapids site examined the feasibility of dam heights of 165 metres and 78 metres. Because of the geological problems of this site, the technical feasibility of a high dam could not be established and the overall costs of the lower dam and power facilities were judged to be excessive at that time. Since that time, ice-jamming problems at Fort McMurray have prompted the investigation of means of alleviating those problems. Such studies suggest that some benefits other than hydro power may accrue to a Crooked Rapids development. These benefits, however, would be relatively minor and would not substantially improve the feasibility of this project. Alternative means of alleviating ice-jamming problems include a small ice control structure upstream of Fort McMurray. A small power plant could be associated with this structure if built. The development of such a power plant, of possibly 30 megawatt size, has not been evaluated. Other tributaries such as the Calling and the Lac La Biche Rivers are too small to be considered for development. Reach D of the river from Fort McMurray to Lake Athabasca, with a gradual fall of approximately 30 metres in 290 km, has a lack of developable sites and is used for navigation. ISO 9001 AUC Energy Study, Rev. 1, Page 11 Hatch 2010/02

26 Alberta Utilities Commission - Update on Alberta's Hydroelectric Energy Resources - February 26, ENERGY POTENTIALS The hydroelectric energy potentials of the Athabasca River basin along with the basic data from which they are determined are shown in Table 1. The drainage area of each reach, tributary or site was measured from the National Topographic Series maps at a scale of 1:500,000. The average flow is estimated from the best available stream flow data obtained from Water Survey of Canada. These data are plotted versus the applicable drainage areas in Figure 7. Data was used from the six gauging stations on the main stem of the Athabasca River, at Jasper, near Windfall, at Athabasca, below Fort McMurray, at Entrance and at Hinton. Records from other stations on the Athabasca River were disregarded because of their sparse data. The station at Athabasca has 94 years of records and the long term average flow value there should be close to true average. Most other stations have somewhat shorter records. The Berland, McLeod and Pembina River tributaries rise in the same area, drain similar topographic regions and are under similar climatic conditions, and therefore, similar relationships based on gauging data or inferred data are established for these rivers in Figure 7. The Clearwater River is a low-profile river which rises in a non-mountainous area and has different characteristics than the other major tributaries in the basin. The gauging station at Draper has relatively long and continuous records and the data from the station above Christina River was adjusted against that from Draper to give continuous records. A regression was completed using this data to represent the average flow - drainage area relationship for the Clearwater River. The gross head for each reach, or tributary or site is taken from the profile given in Figure 6. The TMHE (Theoretical Maximum Hydroelectric Energy) is calculated from the average flow and the applicable gross head using equation 1. The UDHE (Ultimate Developable Hydroelectric Energy Potential) for each reach of the main river and each major tributary is derived by the application of broad judgment and a "development factor" as shown. Reach A, from the headwater to Hinton is almost entirely situated inside the boundary of the Jasper National Park and past investigations did not reveal any attractive sites. Therefore, only a small portion of the hydro energy potential in this reach of the river was considered developable in the foreseeable future. Reach D, between Ft. McMurray and Lake Athabasca was also considered developable for only a small portion because of the flat gradient, low banks, wide valley and the potential interference with recovery of bitumen from the oil sands in the reach. The UDHE is accompanied by estimates of the equivalent plant installed capacities at four arbitrarily assumed capacity factors. The DHE (Developed Hydroelectric Energy) is the minor development on the Astoria River. This plant will not affect, or be affected by, any future hydro development in the basin. ISO 9001 AUC Energy Study, Rev. 1, Page 12 Hatch 2010/02

27 Athabasca River Average Flow (cms) Berland River Clearwater River Pembina River 12 McLeod River Drainage Area (Km 2 ) 1. Athabasca River near Jasper 07AA Athabasca River at Entrance 07AD Athabasca River at Hinton 07AD Athabasca River near Windfall 07AE Athabasca River at Athabasca 07BE Athabasca River below McMurray 07DA Berland River near the mouth 07AC McLeod River Above Embarras River 07AF McLeod River near Wolf Creek 07AG McLeod River near Whitecourt 07AG McLeod River near Rosevear 07AG McLeod River near Cadomin 07AF Pembina River near Entwistle 07BB Pembina River at Jarvie 07BC Pembina River below Paddy Creek 07BA Clearwater River Above Christina River 7CD Clearwater River at Draper 07CD001 AVERAGE FLOW - DRAINAGE AREA RELATIONSHIP ATHABASCA RIVER BASIN FIGURE 7

28 Alberta Utilities Commission - Update on Alberta's Hydroelectric Energy Resources - February 26, 2010 The RDHE-I (Remaining Developable Hydroelectric Energy Potential at Identified Sites) is calculated in the same manner as the UDHE from equation 1. The RDHE-U (Remaining Developable Hydroelectric Energy Potential at Unidentified Sites) is simply the difference between the UDHE and the sum of the DHE and the RDHE-I for each reach, or tributary into each reach of the river. ISO 9001 AUC Energy Study, Rev. 1, Page 13 Hatch 2010/02

29 Table 1 - Hydroelectric Energy Potential of the Athabasca River Basin RIVER, TRIBUTARY, REACH AND SITE CHARACTERISTICS TMHE UDHE DHE RDHE - I RDHE - U DRAINAGE AVERAGE GROSS ANNUAL DEVELOPMENT ANNUAL MW POWER AT CAPACITY ANNUAL CAPACITY CAPACITY ANNUAL MW POWER AT CAPACITY ANNUAL MW POWER AT CAPACITY AREA FLOW HEAD ENERGY FACTOR ENERGY FACTOR OF ENERGY FACTOR INSTALLED ENERGY FACTOR OF ENERGY FACTOR OF (km 2) (m 3 /s) (m) (GWh) % (GWh) (GWh) % MW (GWh) (GWh) ATHABASCA RIVER REACH A - HEADWATER TO HINTON 0-10, ,510 4% ASTORIA PLANT % 1 REACH B - HINTON TO VEGA 10,100-35, ,690 50% 2,850 1, , OLDMAN SITE 11, IMAGE ROCK SITE 11, WILDHAY RIVER % LABYRINTH SITE 1, PINTO CREEK SITE 2, BERLAND RIVER 0-5, % BERLAND SITE 5, MCLEOD RIVER 0-9, ,450 40% MCLEOD VALLEY SITE 8, MCLEOD SITE 9, REACH C-VEGA TO FT. MCMURRAY 35, , ,270 80% 8,220 4,690 2,350 1,560 1, MOOSE PORTAGE SITE 72, , MIRROR SITE 75, ,990 1, PELICAN RAPID SITE 82, ,210 1, GRAND RAPIDS SITE 86, ,770 1, BRULE POINT SITE 88, ,510 1, CROOKED RAPIDS SITE 90, ,310 1, MOBERLY RAPIDS SITE 102, , PEMBINA RIVER 0-14, ,250 40% PEMBINA SITE 4, CLEANWATER RIVER 14,000-31, % WHITEMUD FALLS SITE 14, REACH D-FT. MCMURRAY TO LAKE ATHABASCA 125, , ,280 15% TOTAL OF THE ATHABASCA RIVER BASIN 0-153, ,970 13,050 7,450 3,720 2,477 1, % 1 9,620 8,840 4,430 2,960 2,240 2,873 1, Abbreviation: TMHE: Theoretical Maximum Hydroelectric Energy Potential UDHE -: Ultimate Developable Hydroelectric Energy Potential DHE: Developed Hydroelectric Energy RDHE-I: Remaining Developable Hydroelectric Energy Potential at Identified Sites RDHE-U: Remaining Developable Hydroelectric Energy Potential at Unidentified Sites

30 Alberta Utilities Commission - Update on Alberta's Hydroelectric Energy Resources - February 26, THE CHURCHILL RIVER BASIN 5.1 GENERAL DESCRIPTION One of the headwater tributaries of the Churchill River is the Beaver River which has its source in the Cretaceous plateau, south of Lac La Biche, Alberta. It flows eastward for 370 km and then northward 140 km, emptying into the south end of Ile a la Crosse Lake in the Province of Saskatchewan. In the river section lying within the Province of Alberta there are a number of small lakes and river banks are low. The average flow of the river at Cold Lake reserve is approximately 19 m 3 /s. There appears to be no developable potential as both the river gradient and flow are quite low. Figures 8 and 9 show the plan and profile of the river basin and Figure 10 shows the average flow versus the drainage area relationship. 5.2 ENERGY POTENTIALS Since there is no developable potential for the Churchill River basin, only the theoretical potentials along with their basic data are shown in Table 2. As in the case of tributaries to the larger rivers, some hydro potential could be developed as a secondary benefit if development mainly for other purposes were to occur. ISO 9001 AUC Energy Study, Rev. 1, Page 14 Hatch 2010/02

31 SASKATCHEWAN Beaver Crossing Beaver River km FIGURE 8 CHURCHILL RIVER BASIN

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33 Average Flow (cms) 10.0 Beaver River Drainage Area (Km 2 ) 1. Beaver River near Goodridge - 06AA Beaver River near Dorintosh - 06AD Beaver River at Cold Lake Reserve - 06AD006 AVERAGE FLOW - DRAINAGE AREA RELATIONSHIP BEAVER RIVER (CHURCHILL RIVER BASIN) FIGURE 10

34 Table 2 - Hydroelectric Energy Potential of the Churchill River Basin RIVER, TRIBUTARY, REACH AND SITE CHARACTERISTICS TMHE UDHE DHE RDHE - I RDHE - U DRAINAGE AVERAGE GROSS ANNUAL DEVELOPMENT ANNUAL MW POWER AT CAPACITY ANNUAL CAPACITY CAPACITY ANNUAL MW POWER AT CAPACITY ANNUAL MW POWER AT CAPACITY AREA FLOW HEAD ENERGY FACTOR ENERGY FACTOR OF ENERGY FACTOR INSTALLED ENERGY FACTOR OF ENERGY FACTOR OF (km 2) (m 3 /s) (m) (GWh) % (GWh) (GWh) % MW (GWh) (GWh) BEAVER RIVER BEAVER RIVER 0-15, % Nil Nil TOTAL OF THE BEAVER RIVER BASIN 0-15, % Abbreviation: TMHE: Theoretical Maximum Hydroelectric Energy Potential UDHE -: Ultimate Developable Hydroelectric Energy Potential DHE: Developed Hydroelectric Energy RDHE-I: Remaining Developable Hydroelectric Energy Potential at Identified Sites RDHE-U: Remaining Developable Hydroelectric Energy Potential at Unidentified Sites

35 Alberta Utilities Commission - Update on Alberta's Hydroelectric Energy Resources - February 26, THE HAY RIVER BASIN 6.1 GENERAL DESCRIPTION The Hay River has its source north of the Clear Hills in the north western corner of Alberta. The stream flows west and crosses the (Alberta-British Columbia boundary, continues a distance of some 140 km in B.C. and returns to Alberta, flowing east through Zama and Hay Lakes. It then joins with its tributary, the Chinchaga River which rises just east of the British Columbia boundary. The Hay River then flows north to cross the Alberta-Northwest Territories boundary. Throughout its length in both Alberta and B.C., the Hay River has low banks limiting storage potential. The gorge for which power potential was earlier considered is within the Northwest Territories and therefore is not listed as a part of Alberta's power potential. The estimated average flow of the river just above the Meander River is 76 m 3 /s. Because of the low flow, lack of storage sites and the remoteness of the area, the energy potential of the Hay River considered developable in the foreseeable future was estimated to be small. The plan and profile of the river basin are shown in Figures 11 and 12. Figure13 shows the drainage area and average flow relationship. 6.2 ENERGY POTENTIALS As there is only minor developable potential for the Hay River basin, the theoretical and developable potentials along with their basic data are shown in Table 3. ISO 9001 AUC Energy Study, Rev. 1, Page 15 Hatch 2010/02