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HomeMy WebLinkAboutSUS380®BCHydro Liard River Hydroelectric Studies Information Bulletin No.4 Dece mber 1982 Community Relations Department 970 Burrard Str eet Vancouver, B.C. V6Z IY3 TR23 Sec tion 1.0 2 .0 3 .0 4 .0 5 .0 6 .0 Figure No. 1 2 3 4 LIARD RIVER HYDROELECTRIC STU DIES IN FOR MATION BULLETIN NO . 4 CO I:TEN TS Subject INTRODUCTION STATUS OF LIARD DEVELOPMENT PLANNING AND LICENSING (a) The Planning Process (b) Public Consultation (c) The Project Certification Procedure ENGIN EERING STUDIES (a) Study Region (b) Alternative Development Schemes ENVIRONMENTAL AND SOCIO -E CO NOMI C STUDIES (a) Studies Upstream of Beavercrow (b) Studi es Downstream of Beavercrow TRANSMISSION STUDIES FIGURES Liard-Mackenzie River System Project Area River Profile Transmission Line Study Corridors -i - Page 1 1 2 3 4 5 6 9 9 11 14 ISSN 0228 -9377 1.0 INTRODUCTION This is the fourth information bulletin on B.C. Hydro 's inve~tigations of the hydroelectric power potential of the liard River. The earlier information bulletins were issued in February 1979, September 1979, and Ma rch 1981. Copies are available upon request. Hydro 'S in its fifth year of studies of the engineering and environ- mental feasibility of developing the hydroelectric potential of the Liard River. This bulletin outlines the nature of these investigations, and describes some p reliminary findings. Fo r further ~nformation, please contact: Community Relations S.C. Hydro 970 Burrard Street Vancouver , B.C. VoZ 1Y3 or te 1 ephone ( o 11 ect): 604-663-2405. 2.0 STATUS OF LIARD DEVELOP MENT The Liard River studies program was cut back in 1982 as a result of reductions in the electrical lean forecast for British Columbia and financial restraints implemented during the year by B.C. Hydro. Major segments of the program planned for 1982 were deferred. Howev er, some of the field studies in progress at the time of the cutback were continued. At the present time it appears that the restraints on the liard study program wi 11 continue through 1983 and possibly 1 onger. TR23 -1 - TR23 Studies completed to date show that the liard River development would provide more power, at lower unit cost , than any other river basin currently unrler investigation in British Colu mbia. However, recent long-range projections of B.C . Hydro system requireme nts indicate that po~er from the Liard would not be needed until the year 2000 or later, a deferral of at least two years from previous estimates. No decision has been made by B.C. Hydro whet her or not to 1pply for regulatory approval for any of the Liard River projects, and such a de cision will not likely be made for some time. On the basis of an a ssumed year 2000 in-service date , B.C. Hydro would need to appl y by 1988 to allow sufficient time for regulatory reviews and, if the development wer e approved, construction of the first project and associated transmission facilities. As a result of the s lowd own i n the Liard program, work in 1983 will consist mainly of office studies . Engineering site explorations and environmental fie ld studies previously planned for 1983 have been deferred. However, a limited program of hy drological and environmental data collection will continue, to prov ide additional information for the environmental impact asse ssment studies when they resume. 3.0 PLANNING AND LICENSING (a) The Planning Process It takes 10 to 20 years to plan, desig n, li cense and build a major hydroelectric project. For thi s reason, Hydro mu st look years ahead in examining potential sites . When the need arises for more electricity, projects must be operating to meet that need. There- fore, Hydro's plans must be flexible enough to accommodate events such as a change in electrical demand or the loss of a project (due -2 - TR23 to high cost, environmental or other factors, or rejection at the licensing stage). Hydro selects a sequence of projects to meet projected electricity needs . This sequence is reviewed annually, and adjusted if neces- sary, in the light of new information about projects and electrical demand. Lower-cost energy sources, assuming they could be built in time to meet expected electrical demand, are generally schec1uled first. Such scheduling is in keeping with Hydro's objective of sup~lying electricity at the lowest long-term cost to British Columbia customers. (b) Public Consultation Du ring the planning of potential new projects, B.C. Hydro carries out a publ~c consultation p r ogram to discuss its studies and preliminary plans with interested parties. The public consultation program for the Liard River hydroelec ~ric development provides for participation by government representatives, 1 oca l interest groups and the general p ublic. The program's objectives are: 1. to ensure tha t interested members of the public are informed about the proposed development; 2. to provide opportunities for the public to consult with Hydt·o representative s about the implications of the proposal; 3. to enab l e Hydro to work with representatives of the public in dealing with i ssues pertaining to the proposal, and 4. to assist Hydro in obtaining the information necessary to make informed, responsive decisions. - 3 - TR23 (c) The Project Certification Procedure (i) Regulatory Approvals For Hydro to proceed with construct ion of a major hydro- electric generation or transmission project, it must obtain various approvals, certifica tes , permits and licences. Depending upon the 1 ocat ion, nature and scope of the hydro- electric generation project, provincial statutes which may app ly i ncl ude the Utilities Commission Act, the Water Act, the Agricultural Land Commission Act, the Heritage Conservation Act, the Park Act, the Environment and Land Use Act, the Highway Act, the Envi ronment Managemen t Act and the Forest Act. Federal s tatutes which may apply include the Na vigabl e Waters Protection Act, the Fisheries Act, the Indian Act, the No rthe rn Inland Waters Act and the Canada Water Act. For certain projects o nly some of these statutes would be applicable while for others, s uch as the Liard project, it is anticipated that most or all of the approvals required by the above statutes might be involved. (ii) The Provincial Energy Review Process The Utilities Commissi on Act established a comprehensive me chanism for decision-making on major ene rgy projects. Major hydroelectric generation projects and 500 kilovolt (kV = 1000 volts) transmission lines are su bject to review by and decisions of the Mini ste r of Energy, Mine s and Petroleum Resources, the B.C. Utilities Commission and the Provincial -4 - TR23 Cabinet, in accordance with the p;ocess es tab 1 i shed by the Utilities Commission Act. The Act requires that an applicant for d project provide certain detailed information and an analysis of the impacts created by the project. It makes provisions for a pub 1 i c hearing process which can allow for input from the general public and other interested parties. The Act also provides that the Commission will report and make recommendations after s uch hearings. On receiving the report and recommendations of the Commission , the Cabinet will decide whet~er t o approve or reject the proposal and may set down terms and conditions that it believes to be appropriate. 4.0 ENGI NEERING STUDIES (a) Study Region The Liard River rises in the Yukon and flows southeasterly into British Columbia near Lower Post. The river flows in an easterly direction t hrough British Columbia for about 480 kilometres (km = 5/8 mile) before crossing into the Northwest Territories . A further 370 km downstream, the Liard di s charges into the Mackenzie River at Fort Simpson. From there, the Mackenzi e flows 1390 km to the Beaufort Sea. (See Fig. 1). The Alaska Highway runs parallel to the Li ard River over the western half of the river 's course through British Columbia, as shown in Fig. 2. The principal sett lements and facilities in the Liard s tudy area are located along the highway. Two comm u nities, Lower Post, B.C., and Upper Liard, Y.T., are located near the B. C. -Yukon boundary. The residents of these communities are predominantly native Indians belonging to the Liard River Band - 5 - TR23 (1975 popu 1 at ion, 595). The Muddy River Indian Reserve, 1 ocated near the confluence of the Liard and Kechi~a rivers, has an area of 71 hectares (ha = 2.47 acres). The Liard River Hot Springs and the associated 670 ha Class A provincial park are located at Mil e 496 of the A 1 aska Highway, near Lower Liard Crossing. Larg e areas between Lower Post and Liard River Hot Springs park were burned by forest fires in 1982. (b) Alternative Development Schemes The Liard River development, consisti ng of projects at Devils Gorge and Beavercrow, could provide an installed capacity of about 4410 megawatts (MW = 1 mi 11 ion watts ) and generate about 26 000 gigawatt-hours (GW.h = 1 million kilowatt-hours) of electricity annually. This is greater than the combined output of B.C. Hydro 's two largest generating stations G.M. Shrum on the Peace River and Mica on the Columbia River. The decision to select the Devils Gorge and Beavercrow scheme for detailed investigation was based on preliminary studies of 11 potential development scheme s involving various combinations of six project s ites. Studies of alternative project combinations are reviewed and brought up-to-date from time to time for comparison with the Devils Gorge-Beavercrow scheme. The Devils Gorge (572) project would form a reservoir extending upstream to a point near Lower Post, and Beavercrow (390) would impound water back to Devils Gorge. [Numbers in brackets refer to the nominal maximum normal reservoir elevations, expressed in metres (m = 3.28 feet) above sea level. l Devils Gorge, previously ca 11 ed Site E, is 1 ocated at the head of the Grand Canyon of the Liard approximately 25 km downstream from Lower Liard Crossing, while Beavercrow, previously called Site A, is about 110 km upstream from the B.C.-N.W.T. boundary. -6 - TR23 Due to the nature of the foundation rock at Beavercrow there may be advantages in deve 1 oping the river with a three-project scheme rather than with the two-project scheme described above. The three-project scheme would include projects at Devils Gorge (572), Hell Gate (390) and Beavercrow (342). The Devils Gorge dam would be i dent i ca 1 to the one in the two-project scheme, whi 1 e the Beavercrow dam would be approximately 48 m lower than in the two-project scheme . The profile of the river (Fig. 3) shows the differences in the two scheme s. Preliminary s tudies of the three- project scheme indicate that it would produce slightly less energy than the two-project scheme but might have certain offsetting benefits. Following are descriptions of the components of the two schemes. (i) Devils Gorge (572) Project The Devils Gorge site is located approx imately 25 km down- s tream from Lower Liard Crossing at the upstream end of the Grand Canyon of the Liard. Facilities at this site would consist of an earthfill dam, 200m high, an underground power- house with a capacity of 2490 MW and a gated concrete spill- way. Two saddle dams would be required on the perimeter of the reservoir, one 4 km east and the other 8 km southwest of the main dam. Devils Gorge reservoir would have a surface area of about 890 square kilometres (km2 = 0.3861 mile2) and would be 240 km long at the normal maximum elevation. It would provide 21 x 109 m3 of usable water storage capacity, slightly more than half that of Willi ston Lake, the largest reservoir in British Columbia. The Devils Gorge reservoir would store water during the spring -summer high runoff period, and the stored water would -7 - TR23 be discharged through the turbines during the 10\·1-flow fall- winter period. In a year of average runoff in the Liard River basin, the lowest water level in the Devils Gorge reservoir would be about 17 m below normal maximum reservoir level. Maximum drawdown in a year of extreme low flows would be 30 m. Normally the Devils Gorge reservoir would reach its lowest level of the year in Apri 1, just before the onset of spring runoff. The reservoir would fill or reach its highest level in late summer or early fall. (ii) Beavercrow (390) Project The Beavercrow project would be located about 110 km upstream from the B.C. -N.W .T. bounda ry, about 50 km upstream of the confluence of the Fort Nel son and liard rivers. This prc ject wo uld incla!de an earthfill dam approximately 160m high with a 1920 MW, surface powerhouse and a gated concrete spillway. At its normal maximum elevation of 390 m, the Beavercrow reservoir would have a sur face area of about 190 km 2 and would extend 125 km upstream to Devils Gorge. Under normal opera ting cond itions the Beavercrow reservoir would be held at or near its normal maximum level. However, to meet short-term storage requirements and to mini mize the amount of water that would have to be spi 11 ed, it would be subject to relatively small (about 2 m) water level fluctua- tions, daily and we ekly. (iii) Beavercrow (342) Project The Beavercrow (342) project would con sist of an earthfill dam approximately 112m high, a gated concrete spillway and an 1150 MW surface powerhouse. The reservoir at a normal maximum -8 - TR23 level of 342m would extend to Hell Gate. Reservoir operating conditions would be the same as for Beavercrow (390). (iv) Hell Gate (390) Project Hell Gate is located about 40 km downst:eam from Devils Gorge and 85 km up stream of Beavercrow. Facilities at this site would include a concrete gravity dam and gated spillway and a 720 MW surface powerhouse. The reservoir at a normal maximum elevation of 390m would extend back to Devils Gorge. S.O ENVIRONMENTAL AND SOCIO -ECONOMIC STUDIES (a) Studies Upstream of Bea vercrow 1. Physical Terrain and soil mapping of the Liard River valley has been completed and the information will be used in various other studies, including those concerning highway and access route location. B.C. Hydr o p lans to continue collect- ; ng informati on ab out sediment, temperature and other hydro- logical matters. Further studies on the physical character- istics of the proposed reservoirs have been deferred. Binlnoical Fisheripc: ~t:.:~~c::. 1n the upper Liard dra inage have been completed. Eighteen species of fish occur naturally in the rivers and smaller tributaries. At least 14 species are expecterl to be able to colonize the proposed reservoirs; whitefish and longnose suckers would probably be the dominant ones. The 1 a rgP drawdown zone of the Dev i 1 s Gorge storage reservoir would be an impediment to productivity; most fish species wou1u rely on inflowing tributaries for spawning and rearing habitat. Large proportions of whitefish in the - 9 - 3. drainage have been found to harbour tapeworm cysts (Triaenophorus species, not infective lo humans). Studies of wildlife and wildlife habitat are near completion. Although detailed mapping and study of wildlife habita·:s within the future reservoir area have been completed, the;e and other studies such as those concerning forestry will likely have to be revised due to the changes in vegetation caused by extensive forest fires in mid-1982 . Socio-Economic A preliminary :;tudy of suitabl e sites .1nd corridors for location and relocation of highways, acc·'!ss roads, construction camps and towns i tes is being comp 1 eted . Several potentially suitable corridors for relocation of the Alaska Highway have tentatively been identified, base d on er.gi neeri ng, economic and envi ronmenta 1 cons ide rat i C•ns. Specific alignments would be examined in detail in later investigations. Severa l sections of the existing Alaska Highway and several small settlements wou ld require reloca- tion, but Lower Post and Upper Liard would not be flood·~d. Heritage resource surveys have been undertaken throughout the parts of the the Liard River valley that wou ·l d be flooded. Prehistoric artifacts are sparse throughout the area but relatively more numerous at the confluences of major streams. A prehistoric quarry was found close to the Devils Gor!Je damsite. The remains of Fort Halkett , established at the mouth of the Smith River during the fur trade era, form tt1e most significant historic discovery recorded to date. No further socio-economic studie s within B.C. have take1 place, althoug h liaison has been maintained with communitie:; close to the project areas. -10 - TR2::S (b) Studies Downstream of Beavercrow 1. Physical Hydrological studies have been done of the Liard River below Beavercrow , the mainstem Mackenzie River below the Liard confl uence, the Mackenzie delta and adjacent portions of the Beaufort Sea. B. C. Hydro has maintained a program of hydrological data collection in addition to making use of information collected by various federal government agencies. The effects of the proposed hydroelectric devel opme nt would generally be to reduce high summer flood peaks and increase low winter flows. The effects would diminish with distance downstream from the Beavercrow damsite. Summer flows in the Liard near its confluence with the Mackenzie would average approximately 40 percent lower than non-regulated summer flows, while winter flows would be increased by three to four times. Summer flows in the Mackenzie River just above the delta would be reduced by a bout 15 percent, while winter flows would be increased by 30 to 40 percent. Considerable vari-\ ation in flows, sediments and ice occurs within the present system from year to year. This would continue to occur if hydroelectric development took place; however, there would be changes in the timing and degree of the variations. Although the Liard is a major contributor of suspended sediment to the MacKenzie system, much of the suspended sediment in the Liard River originates in tributaries below the Beavercrow site. Construction of impoundments on the Liard is expected to reduce average suspended sediments in the lower Liard by about 20 percent . A 10 percent reduction in suspended sediments in the Ma ckenzie River and delta is predicted on the basis of the pre 1 i mi na1·y studies . -11 - TR23 B.C. Hydro has recorded water levels in the Mackenzie delta since the beginning of 1981. Fluctuations in various types of 1 ake s and sma 11 channe 1 s are monitored throughout the open water season . This information is being used to study the distribution and seasonal changes in delta vegetation, and to predict how vegetation and wildlife habitats might change following liard River flow regulation. Extensive investigations of annual break-up and freeze-up on the liard and Mackenzie rivers and in the delta have been undertaken. Under regulated conditions break-up near Fort liard would probably occur from 1 to 2 weeks earlier, while freeze-up would take place 3 to 4 weeks later than under natural conditions. Break-up and freeze-up dates on the Mackenzie River are not expected to change by more than 2 or 3 days . Observations of break-up and freeze-up are continu- ing . Satellite imagery of the Beaufort Sea is being used as a means of studying any possible effects of Mackenzie River flow changes on the seasonal distribution of ice along the coast and in the offshore areas north of the delta. 2. Biological Detailed mapping of vegetation in seven study areas in the Mackenzie delta has been completed, and factors such as sedimentation rates , flooding frequency, and various plant and lake characteristics have been measured. Studies of colonization of point bars by wi llow seedlings are being undertaken. Studies of muskrats and waterfowl in the Mackenzie delta have been under way since spring 1982. The major objectives are to relate the distribution, local abundance, breeding success and other population parameters to hydrological and vegetational characteristics . Studies may not extend beyond 1982, due to the present fiscal restraint program, but may be resumed -12 - TR23 later. Surveys of the migratory waterfowl populations using the Mackenzie River valley as a flyway were undertaken in 1981 and 1982. The largest concentrations of geese and ducks tend to make use of the valley during the annual spring break-up. Fisheries studies have proceeded throughout the lower Liard River, the Mackenzie River, and in specific study areas in the Mackenzie delta. The Beavercrow dam would block upstream migrations of some fish such as Arctic cisco and inconnu, and flow changes within the mainstem Liard may affect habitats of some species. Fish habitat changes in the mainstem Mackenzie ) would be expected to be small in relation to naturally- occurring variations. The main aspects being studied in Mackenzie delta lakes include seasonal influx of nutrients following flooding, movements of young and adult fish into and out of the lakes, and the productivity of lakes, some of which are flooded annually, others periodically and some very seldom . 3 . Socio-Economic - A preliminary socio-economic study of N.W. T. communities along the Liard and Mackenzie is being comp 1 eted, based on pub 1 i shed and other data in federa 1 and territorial government files . The purpose of this study is to identify communities, areas and resources which would be affected by the proposed project, and to enable B.C. Hydro to formulate detailed study plans . Detailed socio-economic studies have been deferred for the present, pending further project decisions. Extensive liaison with communities in the N.W.T . would be part of the eventual detailed socio-economic study program . -13 - 6.0 TRANSMISSIO N STUDIES Extra high-voltage transmission lines would be needed to take pQwer generated by the Liard River development to the existing province-wide transmission network. Liard transmission probably would be connected to the provincial system in the Prince George area . TR23 Transmission systems rated at 500 kV, 800 kV and 1000 kV are being considered, as well as direct current systems that would take Liard power directly to the Lower Mainland. At present, the most favourable alternative appears to be three 500 kV lines. However, more study would be required before a final decision could be made on transmission voltage, type and number of lines. The choice of transmission routes (see Fig. 4) would depend on the environmental and social impacts, transmission line design and construc- tion constraints, costs, and long-range requirements of the provinc ia l electric system. An overview study ident ifying potential transmission line corridors from the Liard and Stikine-Iskut hydroelectric developments has been comp 1 eted. (See Prospectus Northern Transmission Studies, July 1980). One of the most notable effects of transmission lines from the northern hydroelectric projects could be the creation of motor vehicle access into wilderness areas by rights-of-way and roads required to construct and maintain the lines. Transmission lines following any of the routes being considered would pass ~ear Indian reserves and lands used by local residents. Environmental and technical studies have begun to determine which o f the potential routes might be preferable. Among the factors that are being considered are the impacts that could occ ur to wildlife habitat, -14 - TR23 fisherie s , recreation potential, vegetation, heritage sites and land use. The s tudies are also examining the cos t and technical difficulty of transmission line construction on each of the potential routes. Field studies have been carried out. No further work is s cheduled , however, because c f the current restraint program and the uncertainty a s to when development of the Liard might be required. -15 - I I . ALASKA , IIIA C KlNZil I I D[LTA . I I I I I I I r o iiT lolc,.HOISOII j .. l.~ j \ ·, I I ~ YUKON TERRITORY ~ ') ) ' BR ITISH COLUMBIA ~ DRAINAGE BASIN FOR ~ LIARD RIVER DEVELOPMENT NORTHWEST TERRITORIES ALBE RTA SC ALE 0 100 200 300 km ~ LIARD RIVER HYDROELECTRIC STUDIES • -LI ARD-MACKENZIE RI V ER SYSTEM FIGURE I MUDDY RIVER I.R. 0 10 20 30 40 50 k m LIARD RIVER HYDROELECTRIC STUDIES PROJECT AREA FIGURE 2 DEVILS GORGE PROJECT BEAVERCROW PROJECT LIARD RIVER HOT SPRINGS · PROVINCIAL PARK HELL GATE) SITE HIGHWAY MUDDY RIVER I.R. 0 10 20 30 40 50 k m LIARD RIVER HYDROELECTRIC STUDIES PROJECT AREA FIGURE 2 DEVILS GORGE PROJECT BEAVERCROW PROJECT LIARD RIVER HOT SPRINGS · PROVINCIAL PARK HELL GATE) SITE HIGHWAY Ch w 0:: 1- w ~ z z 0 ~ <t > w _J w 750~ ~~~ 6501-t----+-~~ )-l<t a:-om ~::E -:::> O::...J a:::•o wu ~ ~ ~ Z ~ l l DEVILS GORGE <l:'w o,-m a::: ~~ ::E~ :::> 0:: EL.572 ~ ~-----+----~~~~>-m 3 o:: I ~ oo:: 550 0 -~ -=-~BE AVER CRO WI u ,w t-t----+----+ o:: ----+ll-t----+---+-~J_jt---==--+~__..;;::o-....__ \ I :r: ~ 450 ~ ~ ~~ -+--lft--.._ EL.390 " g ~ ~ ~-----+-----+-w ---~1-u u '4. ' _J 0:: 0::: ~ "15 01-+------+------+-8:: ~ <nl-~ ~ JU> ~ EL .3 4-2-... ~ ~ ffii:C ,J :::> ~ zu t..L-wC>~ <4l -....... 1-0: ~ I 0 ~;:! T 0:: >Zo:: w ~~ 0:: 0:: • T_J -~ zo • _J o: oc <ta.. ~ j«4:.__ e o 250 <t on.. <!> --I Z t-t------1-------+-----H, ,----+--+1 ju -+---+o o:: U> > ..J --r---._ 1 <; <tl-0 ..J I -., t-+----+-----+------+------+----11--4-----H-----+ -0 a: --w J--------il------+------+---1 I I -{r.a.. f 150~----~-----L----~--~--~----~--~L--L---~~-~----~---~--~ 1000 950 900 850 800 750 700 650 600 550 DISTANCE IN K ILOM ETRES F ROM FORT SI M PSO N LI ARD RIVER HYDROELECTRIC STUDIES RI VE R PR OFILE FIGURE 3 500 4 50 400 370 7 50 650 550 450 350 250 150 n n 0 (\ "' .,.. LIARD RIVER HYDROELECTRIC STUDIES TRANSMISSION LINE STUDY CORRIDORS F IGUR E 4 100 f ..... l l l •fl\e ' ""''~ 1/Ytll t ,, .• ·-·-·-·-·-·-·-· ·-·-·-· u S A. 0 100 200km "·\ • Mr. W. J. Wilson, Supervisor ®BC.Hydro IJ70 Burrard So-eel · Vancouver B.C. V6Z I Y 3 Telex04·54395 25 January 1983 Resource Science and Cultural Sciences Div. Arctic Environmental Information and Data Centre University of Alaska 707 A Street Anchorage, Alaska, 99501 Dear Mr. Wil son: Liard River Hydroelectric Studies Informati on Bulletin No. 4, December 1982 Enclosed for your information is a copy of the above bulletin. \ Hydro is in its fifth year of studies of the engineering and environmental feasibility of developing the hydroelectric potential of the Liard River. This bulletin ou tlines the nature of these investigations, and describes some preliminary findings. The bulletin has been distributed to elected representatives , government officials , community organizations, university and local public libraries and other interested individuals in the project area. Should you require further information or additional copies, please contact me at B. C. Hydro's Community Relations Department, 970 Burrard Street, Vancouver, B. C., V6Z 1Y3 or telephone 663-2405. Sincerely, Eric D. Powell Community Relations Coordinator Enclosure