DAMS AND ENVIRONMENT Case histories. Commission Interпatior1ale des Graпds Barrages 151, bd Haнssmanп, 75008 Paris - Tel. : 47 64 67 33 - Hlex : 64 1320 F (ICOLD) NOTICE – DISCLAIMER : The information, analyses and conclusions referred to herein are the sole responsibility of the author(s) thereof. The information, analyses and conclusions in this document have no legal force and must not be considered as substituting for legally-enforceable official regulations. They are intended for the use of experienced professionals who are alone equipped to judge their pertinence and applicability and to apply accurately the recommendations to any particular case. This document has been drafted with the greatest care but, in view of the pace of change in science and technology, we cannot guarantee that it covers all aspects of the topics discussed. We decline all responsibility whatsoever for how the information herein is interpreted and used and will accept no liability for any loss or damage arising therefrom. Do not read on unless you accept this disclaimer without reservation. СОММIТТЕЕ ON ТНЕ ENVIRONMENT (*) (1985- 1991) Chairman Great Britain Е.Т. HAWS Members Brazil J.A. BANDEIRA DE MELLO Canada G. GUERТIN China ZHANG ZEZHEN Finland Т. KOVANEN France Р. SAVEY Indonesia М. UMAR Italy С. LОТТI Japan Т. KANEYASНIKI Malaysia DATO' MOHD JALALUDDIN N etherlands Н. ENGEL New Zealand Е. HEINE Portugal А. GON<;:ALVES Spain Е. R. PARADINAS Sri Lanka W.M.S.C. PIYADA SA Sweden Во. STEN Switzerland N. SCHNIТТER USA J. W. MORRIS USSR L. Р. MIKHAILOV Co-opted member L. О. ТIMBLIN (*) Membership in April 1988. 2 CONTENTS INTRODUCTION GENERAL SUMMARIES 1. POWER STATIONS ON ТНЕ DANUBE AND INN RIVERS (Austria) 2. ТНЕ LOKKA AND PORTТl­ PAHTA RESERVOIRS (Finland) 3. ТНЕ SUORVA DAM (Sweden) 4. ТНЕ SELINGUE DAM (Mali) 5. ТНЕ SANTE E COOPER PRO­ JECT (USA) 3 TABLE OF CONTENTS INTRODUCТION GENERAL SUMMARIES 1. POWER STAТIONS ON ТНЕ DANUBE AND INN RIVERS (Austria) 1. Introductioп 2. Descriptioп of schemes 2.1. Оп the Inn river 2.2. On the Daпube river 2.3. The maiп purposes of the projects 3. Impact оп the eпviroпmeпt 3 .1. The 1 nn reservoirs 3.2. Giessgaпg-Greifeпsteiп power scheme on the Daпube References 5 figures - 2 colour photos 2. ТНЕ LOKKA AND РОRТТIРАНТА RESERVOIRS (Fiпlaпd) 1. Descriptioп of the project 2. Project outputs 3. Significaпce to the economy апd socio­ logy 4. Eпviroпmeпtal impacts of reservoirs 5. Significaпce of eпvironm'eпtal impacts Summary Referreпces 6 figures - 5 photos 5 З. ТНЕ SUORVA DAM (Swedeп) 1. The project апd its sigпificaпce 1.1. Locatioп 1.2. ConstrL1ction phases 1.З. ProЬ\ems dL1riпg constrL1ction and transport conditioпs. 1.4. The import;шce оГ the Suorva Dam INSET OF COLOUR PHOTOS FOR CHAPTLRS 1, 3, 4 2. Eпvironmeпtal impact 2. 1. General 2.2. The Suorv-a Dam and reiпcieer husbaпdry 2.3. The Suorva [)am and f'ishing 2.4. The SL1orva f)am and tourism Ret'erences 5 figures - 4 colour photos 4. ТНс SELINGUE DЛМ (Mali) 1. Caracteristics о/' the dam 2. Environmeпtal issues 3. The sitllatioп after the dam coпstrL1c- tioп З. 1. PopL1latioп transfer 3.2. fnergy 3.3. AgricL1lture З.4. PiscicL1ltL1re 3. 5. Health 3.6. Education 4. ConclL1sions 2 colour photos 5. ТНЕ SANTEE COOPER PROJECT (USA) 1. 1 ntrodL1cti oп 2. Settiпg and early history 3. Description б INTRODUCTION The Committee on the Environment of the lnternational Commission on Large Dams (ICOLD) has previously puЫished three Bulletins (35, 37 and 50). The Гirst was largely of а technical nature, and the second for the better information of the general puЫic. The third distilled the experiences of engineers involved with dam projects located in broadly defined climatic regions of' the world, the regions chosen being designated as temperate, tropical, sub-tropical and arid; and severe winter. This Bulletin, the t'ourth of the series presents а number of case histories. They are dams and reservoirs generally of а signiГicant age. Thus а realistic picture is now availaЫe ot'the performance ot'each scheme related both to achievement ot' the main project purpose and to the various environmental impacts involved. lt is intended that the reader should Ье аЫе, through these descriptions, to assess the overall impact ot' each project in its tota\ity on the communities and countries involved. Не сап thence make his own judgement of the overall degree ot' success ot' the project. It must Ье emphasised that since projects ot'sign iГicant age have been selected, for reasons given above, the cases рrоЬаЫу do not indicate the most modern practice in dealing with environmental matters. lndeed in several instances lessons learned are recorded which all add to the current state of the art and best practice. Cases have been contributed herein t'rom the National Committees ot' Austria, Finland, Swedc:п, ltaly (f'or Selingue Oam, Mali) апd USA and acknowledgement is made to the authors. It is hoped to add to the list of case histories in а t'uture bulletiп. Е. Т. Haws Chairmaп Committee on the Enviroпmeпt For а comprel1ensii'e aide memoire and met/10dology approach /o r environmental impact studies, t/1e matrix о/' Bulletin 35 is recommended, and it тау he notecl that tl1e matrix is availahle in hatcl1es as а separate set. 9 GENERAL When dealing with environmental alteration, it is necessary to clearly distin­ guish between two terms which are often and erroneously being used as synonyms while, in fact, they have а distinct meaning ; preservation and conservation. " Preser­ vation" means to keep something -- in this case the environment - free from injury and alteration in its original state, whilst " Conservation " admits, in this context, some adaptation to а new though equiv<1lent or improved equilibrium that is to Ье maintained. Mankind depends more and more on the development and exploitation оГ natural resources. Consequently, n<1ture cannot Ье preserved everywhere in an un<1ltered condition. On the other hand, it is оГ utmost importance to conserve nature and its resources and to protect the physical environment Гrom avoidaЫe harm and disturb<1nces. Formerly, man's achievements were welcomed, and great hopes were held Гоr continuing the advance into new are<1s оГdevel opment. Recent puЫic awareness has leaned towards conservation and developers must now clearly р<1у the gre<1test <1ttention to ecolological proЫems, and to any aspect of' <1 scheme which may <1ppear as а threat to the environment. It must Ье possiЫe to t<1ke <1dvantage оГ natur<1I resources without d<1maging nature. This concern must Ье m<1nif'est both ЬеГоrе and during the implement<1tion оГ works, <1nd during the entire oper<1ting lif'e оГ the structures. The descriptions in this bulletin describe specif'ic w<1ter resource projects <1nd their overall еГГесts, both economic <1nd environmental. However, the re<1der should <1lso have in mind the wider comparison between the water resource project <1nd <1 substitute scheme which could achieve the same main objective. Thus in the case оГ <1 hydroelectric power project the altern<1tive might Ье а thermal station fu elled Ьу oil, coal or ur<1nium with all the associated environmental implic<1tions. Also, the hydroelectric scheme utilises а renewaЫe energy source, whilst burning Гuel Гоr <1 thermal station represents disposing оГ а natural resource which has fi nite limit. Experience has shown that neglect оГ environmental aspects linked to the construction оГ large dams and reservoirs can le<1dto ecologic<1I proЫems. However, the need is now recognised for modern engineering science to Ье used in conjunction with the ecological and soci<1I sciences and in combination they now provide the proven capability to plan, design, build and operate dam projects with minimum unexpected or unaccept<1Ьle environmental еГГесts, as m<1y Ье observed in the descriptions оГ the projects presented in this bulletin. An essential assessment is the balance between e/Tects and impacts on the environment <1ndthe benefits expected from а dam. Such an assessment necessarily takes into account the physical needs and economic situation ofthe country concerned. А nation starving Гоr energy with water power as the only availaЫe source, Гоr instance, is certainly more inclined to change the environment оГ а particul<1rspecies than another which has the choice between 11 several viaЫe power alternatives. Nevertheless necessary dam projects should always Ье engineered to fit into the environment in an optimum way. There is а .need to make the best overall use of the world's finite natural resources, and in the case of water this requires that the best possiЫe advantage Ье taken of а reservoir Ьу using the dammed waters for as many purposes as reasonaЫy fe asiЫe. Even when а dam is built initially for а sing\e purpose, those who have the responsibility for the management of the water retained in the reservoir, should evaluate the operating conditions taking into account other future uses of the dam. The reader may observe the effect of some of these influences in the project descriptions which fo llow ( chapters 1 to 5). The five case histories deal with projects in Arctic, Alpine, temperate and tropical regions. The range of environmental aspects involved is enormous. Nevertheless the responsiЫe engineers and develo­ pers have showed great flexiЬility and imagination in maximising benefits and minimising or mitigating proЫems. The original project aims have all been subs­ tantially achieved and in every case the overall effect is recognised as highly beneficial to the populations and countries involved. 13 SUMMARIES OF CASES 1. The Danube and lnn developments, in Austria, are large Поw, low head developments. Although only а few power schemes were originally planned, it was soon realised that а continuous cascade of power schemes was desiraЫe both from the power generation and river morphology points of view.