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Latin America and Carribbean Region Sustainable Development Operating Paper sixteen Good Public works and Bad Dams: Environmental Criteria pertaining to Site Selection of Hydroelectric Projects November 2003 George Ledec Juan David Quintero The World Bank Latin America and Caribbean Location Environmentally and Socially Sustainable Development Department (LCSES) Latina America as well as the Caribbean Place Sustainable Creation Working Conventional paper No . sixteen Good Atteinte and Awful Dams: Environmental Criteria for Site Number of Hydroelectric Projects November the year 2003

George Ledec Juan David Quintero The earth Bank Latin America plus the Caribbean Region Environmentally and Socially Sustainable Development Sector Management Device George Ledec has worked together with the World Lender since 1982, and is at present Lead Ecologist for the Environmentally and Socially Sustainable Development Device (LCSES) worldwide Bank’s Latin America and Caribbean Local Office. He specializes in the environmental assessment of development tasks, with particular focus on biodiversity and related conservation oncerns.

He did extensively with all the environmental aspects of dams, tracks, oil and gas, forest management, and guarded areas, and it is one of the main experts of the World Bank’s Natural Demeure Policy. Doctor Ledec received a Ph. D. in Wildland Useful resource Science from the University of California-Berkeley, a Masters in public places Affairs coming from Princeton College or university, and a Bachelors in Biology and Environmental Studies from Dartmouth College.

Juan David Quintero joined the World Bank in 1993 which is presently Lead Environmental Consultant for LCSES and Manager of the Bank’s Latin America and Carribbean Quality Assurance Group, which watches compliance with environmental and social safeguard policies. He specializes in environmental assessment of infrastructure assignments, mainly streets, hydropower, gas and oil, urban travel, and hydrant and sanitation. He has received the Regional Award from your International Association for Impact Assessment (IAIA) for advertising improvements in environmental influence assessments throughout Latin America.

He is a civil engineer with postgraduate degrees in Environmental and Sanitary Engineering. The conclusions, interpretations, and conclusions through this document happen to be those of the authors, and should not end up being attributed in any manner to the World Traditional bank, its connected organizations, associates of its Board of Executive Administrators, or the countries they symbolize. This working paper series is manufactured by the Ecologically and Socially Sustainable Creation Sector Management Unit in the Latin America and Caribbean Regional Office. Additional copies may be extracted from the experts or coming from LCSES System Assistant Philip Brandriss ([email, protected] rg, or tel. 1-202-473-9379). Cover photos (clockwise from top left): Loksop Dam, South Africa Guavio Atteinte, Colombia Yacyreta Dam, Argentina/Paraguay All photographs by George Ledec 2 Contents Acknowledgments , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,.. iv Foreword , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,.. v Executive Summary, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ii Intro , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , 1 Negative Environmental Impacts of Hydropower Development , , , , , , , , , , , , , , , , 3 Key Symptoms of Most likely Environmental Impacts , , , , , , , , , , , , , , , , , , , , , , ,.. 9 Overview of Ecologically Good and Bad Hydroelectric Dam Sites , , , , , , , , , , , 13 Conclusions , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,.. 5 Bibliography, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,. 17 Dining tables 1 . Hydroelectric Projects: Undesirable Impacts and Mitigation Choices 4 installment payments on your Land Region Flooded and folks Displaced in Large Hydropower Projects 3 12 Acknowledgments Doug Mason (consultant) compiled data in more than twenty completed Latina American hydroelectric projects, this information was very helpful in our analysis of environmental and interpersonal impacts, minimization measures, and site collection criteria.

Many current and former Community Bank Group staff members presented useful remarks and much encouragement, including Alessandro Palmieri, John Briscoe, Teresa Serra, Tony a2z Whitten, Robert Goodland, Durchgang Ziegler, Warren Van Wicklin, William Partridge, Maria Clara Mejia, Kristine Ivarsdotter, Mateen Thobani, Salman Salman, and A. L. Glauber. This paper likewise reflects the helpful remarks provided by Dominique Egre and Gaitan Guertin (Hydro-Quebec), Jose Goldemberg (World Commission on Dams), and Paul Dulin. Peter Brandriss helped edit and put together the report for publication. iv Foreword

Few types of creation projects excite as much controversy as hydroelectric dams. Their particular often serious environmental destruction has been nicely documented inside the past ten years. non-etheless, various countries, in Latin America and around the world, rely upon hydroelectric dams for any major area of their energy. Electricity remains a key component for improving the lives of the indegent almost everywhere. In developing countries, rapid estate and extended population development will ensure increased demand for electrical power for decades to come, even with the most effective of demand management and energy effectiveness measures.

Strength planners in several developing countries are therefore likely to continue seeing hydroelectric dams being a promising method to obtain renewable electric power. This report provides crucial advice for substantially reducing the environmental harm from long term hydroelectric dams (whether or perhaps not they will receive World Bank Group financing) through good task site variety. Although the report’s conclusions are drawn generally from an assessment Latin American dams, its innovative strategy for atteinte site selection, based on powerful environmental and social requirements and straightforward, quantitative indicators, should prove valuable worldwide.

The report likewise helpfully summarizes the environmental mitigation options pertaining to the superior operation of existing hydroelectric dams. As such, this record should be of considerable curiosity to people interested in hydroelectric atteinte, whether with the World Lender, other multilateral and bilateral development organizations, government agencies, personal energy businesses, consulting companies, environmental and also other NGOs, and academia. This kind of report can be part of the LCR Sustainable Expansion Working Conventional paper Series released by the Latin America and the Caribbean Region’s Environmentally and Socially Eco friendly Development Sector Management Unit (LCSES).

This course seeks to disseminate the results of our analytical and operational operate, present preliminary findings, and describe “best practices with respect to major eco friendly development problems facing the region. The studies, interpretations, and conclusions portrayed in these papers are entirely those of the authors and really should not be attributed to the earth Bank, associates of it is Board of Executive Directors, or the countries they represent. John Redwood Director Ecologically and Socially Sustainable Expansion Latin America and Caribbean Region The earth Bank v Executive Brief summary

Large dams vary noticeably in their adverse environmental and related interpersonal impacts. Coming from an environmental standpoint, you will find relatively good dams and bad public works. While some large dams are relatively harmless, others possess caused major environmental harm. The severity of environmental impacts coming from a hydroelectric project is essentially determined by the dam site. While public works at great sites can be extremely defensible by an environmental standpoint, these proposed at bad sites will inherently be extremely problematic, even if all feasible mitigation procedures are effectively implemented.

This kind of paper supplies a simple, yet robust, strategy for assessing proposed hydroelectric project sites in terms of their particular expected unfavorable environmental effects, and relating these to power technology benefits. The paper as well summarizes the environmental mitigation choices for significant dams. In the event that properly implemented, these mitigation measures can effectively prevent, minimize, or perhaps compensate for various (though not all) of the hydroelectric project’s negative affects.

Nonetheless, the best environmental mitigation measure is good site collection, to ensure that the proposed dam will cause relatively little destruction in the first place. The paper presents quantitative indicators (using info that are not too difficult to obtain) for rating and rating proposed new hydroelectric assignments in terms of their particular likely unfavorable environmental impacts. Projects having a small water tank surface area (relative to electricity generation) usually be most desirable via both a great environmental and social viewpoint, in part because they minimize natural habitat losses along with resettlement needs.

In general, the most environmentally harmless hydroelectric atteinte sites are on upper tributaries, while the most problematic kinds are on the top main comes of rivers. Power growth planning should certainly ensure that environmental criteria, of the type defined in this conventional paper, are given suitable weight in hydroelectric task site collection. Many of the even more problematic dam sites are best left undeveloped, because the environmental or related social influences are likely to be unacceptably high. In those cases, other electric power generation solutions are likely to be even more environmentally desired.

Conversely, hydroelectric dams at good sites (with comparatively low unfavorable impacts) and with successful implementation of proper mitigation measures are likely to be more attractive by an environmental standpoint than the most likely electrical power generation alternatives. vii Intro 1 . Large hydroelectric atteinte are among the most controversial of types of development assignments. They have been the focus of much criticism of the World Financial institution and other intercontinental financing companies. The “large dams issue is often highly polarized.

Experts of large hydroelectric projects indicate a wide range of unfavorable environmental and related social impacts, from your destruction of unique biodiversity to the displacement of susceptible human populations. Defenders of large dams be aware that they are often the economically least-cost source of energy available, especially to large urban centers, they are a renewable electrical energy source, and a lot other electrical power generation systems also mean significant unfavorable environmental affects. 2 .

Throughout the world, many countries rely upon hydropower for a substantial portion of their electricity. In developing countries, rapid urbanization and continuing population progress will ensure improved demand for electric power for decades to come, in spite of the most successful of demand management and energy efficiency measures. Electricity remains a key ingredient to get improving the lives of millions of the indegent throughout the developing world. Strength planners in many countries are likely to continue seeing hydroelectric dams being a promising, renewable source of electricity.

Major recent foreign initiatives, like the World Summit on Eco friendly Development (Johannesburg, 2002), World Water Community forum (Kyoto, 2003), World Commission payment on Dams (1997-2002), and the ongoing Public works and Advancement Project from the United Nations Environment Program, have reaffirmed the commitment of numerous governments and international agencies (including the World Bank) to hydropower development, but in a manner which totally reflects modern day environmental worries. 3. From this context, it is important to remember that every large hydroelectric dams are generally not alike.

Large hydroelectric projects vary greatly in the degree of their undesirable environmental and related interpersonal impacts. (In this daily news, we define large hydroelectric dams as those with twelve megawatts or even more of set up generating potential, to distinguish these people from small or micro-dams which generate power on a smaller size. ) For instance , the 500″megawatt Pehuenche Hydroelectric Project in Chile inundated only about four hundred hectares of land (with minimal harm to forest or wildlife resources) and has had no water quality concerns.

By contrast, the Brokopondo Dam in Suriname inundated regarding 160, 500 hectares of biologically valuable tropical jungle and is known for serious normal water quality and aquatic pot problems, when providing comparatively little electrical generating capability (only 40 megawatts). four. We conducted a review of much more than twenty finished hydroelectric atteinte projects in Latin America, along with several recognized projects from the other regions. Each of our study discovered that some large public works are relatively benign, while some have caused substantial environmental and related social destruction.

This daily news provides a methodology for quickly comparing suggested hydroelectric task sites with regards to their predicted adverse environmental impacts, relative to their power generation benefits. The technical criteria and quantitative signals in this conventional paper should be considered as complementary to 1 2 LCR Sustainable Expansion Working Conventional paper No . of sixteen the broader and often more process-oriented suggestions of different recent reports about dams, such as 2000 Public works and Expansion report on the planet Commission in Dams.

This paper’s recommendations are totally compatible with the World Bank’s Normal water Resources Sector Strategy, although this paper provides even more technical depth regarding particular environmental affects, mitigation choices, and site selection standards. Adverse Environmental Impacts of Hydropower Creation 5. The number of undesirable environmental and related social impacts that could result from hydroelectric dams is remarkably various. While some influences occur only during construction, the most important affects usually are because of the long-term living and procedure of the atteinte and tank.

Other significant impacts may result from complementary civil performs such as gain access to roads, power transmission lines, and quarries and borrow pits. Desk 1 summarizes the unfavorable environmental and social influences associated with dams and reservoirs, along with the standard kinds of minimization measures frequently proposed (and, less often , effectively implemented). 6. The analysis indicates that with properly executed mitigation steps, many of the bad environmental and related interpersonal impacts of hydroelectric projects can be reduced to extremely acceptable amounts.

As discussed in Table 1, minimization measures can effectively prevent, minimize, or perhaps compensate for the majority of adverse impacts, but only if they are properly implemented. In our review of Latin American hydroprojects, we located wide deviation in the extent to which environmental mitigation measures were planned, budgeted, and actually implemented. six. Moreover, for a few types of negative influences, at some job sites, the available minimization measures”even once properly implemented”are inherently bad.

Examples of unfavorable environmental influences which arise at some hydroelectric projects and cannot be completely mitigated contain (i) permanent biodiversity damage, if essential natural habitats not occurring elsewhere are submerged (or left dry) by the dam, (ii) fish passage establishments frequently cannot restore the pre-dam ecological balance of the river, in terms of species formula or seafood migrations, and (iii) a lot of cultural property (including sacred sites) cannot be adequately salvaged prior to tank inundation. 8.

Thus, since mitigation actions are often certainly not fully applied, and are occasionally inherently not enough, the single most critical environmental minimization measure for any new hydroelectric project is good site selection, to ensure that the proposed atteinte is will probably be largely not cancerous in the first place. In the following overview of common adverse environmental impacts and corresponding mitigation options, it is necessary to keep in mind that all these types of impacts can be either avoided or minimized through good job site collection. 3 5

Note: Most of these impacts could be avoided or minimized when i say good dam web page selection, the only most important environmental measure. Environmental Impacts Minimization Options Effects of the Atteinte and Reservoir Flooding of Natural Habitats Some reservoirs permanently flood extensive all-natural habitats, with local and in many cases global disparitions of animal and grow species. Very large hydroelectric reservoirs in the tropical forests are especially prone to cause species extinctions (although such deficits are only seldom documented due to the lack of scientific data).

Specifically hard-hit happen to be riverine jungles and other riparian ecosystems, which usually naturally occur only along rivers and streams. From a biodiversity conservation standpoint, the terrestrial natural habitats lost to flooding are generally much more useful than the marine habitats created by the reservoir. One periodic exception to the rule is that shallow reservoirs in dry out zones can offer a permanent oasis, sometimes very important to migratory waterfowl and other terrestrial and marine fauna.

To offset losing natural demeure to tank flooding or other task components (such as acquire pits), one or more compensatory protected areas could be established and managed underneath the project. In the event that an existing area is protected “on paper only, a helpful project choice is to strengthen its onthe-ground protection and management. The spot protected beneath the project should certainly ideally carry comparable or greater size and ecological quality towards the natural location lost towards the project.

Underneath the World Bank’s Natural Refuge Policy, hydroelectric and other projects should not be placed where they will cause the significant conversion or perhaps degradation of critical normal habitats which experts claim not arise elsewhere (and, hence, may not be adequately compensated). Loss of Terrestrial Wildlife The losing of terrestrial creatures to too much water during tank filling is usually an inherent effect of the water damage of terrestrial natural habitats, although generally treated like a separate effects. Although they might be useful for pr purposes, wildlife rescue work rarely succeed in restoring crazy populations.

Rather than drowning, the captured and relocated pets typically starve, are killed by competition or predators, or neglect to reproduce efficiently, due to the limited carrying potential of their new habitats. Animals rescue is most likely to be validated on preservation grounds in the event (a) the species preserved are globally threatened with extinction and (b) the relocation an environment is environmentally suitable and effectively protected. However , the money spent on save would usually do considerably more for wildlife conservation if this were invested in compensatory guarded areas.

The simplest way to minimize creatures mortality in hydroelectric projects is to select dam sites which reduce the wildlife habitat overloaded. LCR Sustainable Development Operating Paper Zero 16 Table 1 . Hydroelectric Projects: Undesirable Environmental Influences and Mitigation Options Environmental Impacts Mitigation Options Involuntary Displacement Unconscious displacement of individuals is often the main adverse social impact of hydroelectric tasks. It can also include important environmental implications, such as with the conversion of natural habitats to accommodate resettled country populations.

To get physical shift, the main minimization measure is the resettlement of displaced populations, including new housing, substitute lands, and other material assistance, as necessary. Success generally requires discussion and participatory decisionmaking simply by both the resettled and host populations (mandatory for World Bank”supported resettlement). Effective resettlement of vulnerable ethnic hispanics is particularly challenging because some of these people are remarkably vulnerable to negative social alterations.

Accordingly, the earth Bank’s Involuntary Resettlement and Indigenous Peoples policies afford special consideration to these masse, specifying that, among other requirements, most viable substitute project styles should be explored before looking at physical displacement for these organizations. For people who are not physically out of place but go through an economic decrease of livelihoods (based on the fishing industry, agricultural or perhaps grazing lands, river-edge clay-based for brick and floor tile production, or perhaps other resources), mitigation steps should entail the dotacion of alternative resources, new job teaching, or additional income recovery assistance, since needed.

Degeneration of Normal water Quality The damming of rivers can cause serious drinking water quality deterioration, due to the reduced oxygenation and dilution of pollutants by relatively still reservoirs (compared to fast-flowing rivers), flooding of biomass (especially forests) and resulting underwater corrosion, and/or tank stratification (where deeper pond waters lack oxygen).

Water quality control actions (such while sewage treatment plants or perhaps enforcement of business regulations) could possibly be needed to increase reservoir drinking water quality. In which poor drinking water quality might result from the decay of flooded biomass, selective forest clearing inside the impoundment place should be completed before reservoir filling. Downriver Hydrological Alterations These unfavorable impacts can be minimized through careful administration of normal water releases.

Targets to look into optimizing water releases through the turbines and spillways include adequate downriver water supply pertaining to riparian ecosystems, reservoir and downriver seafood survival, reservoir and downriver water top quality, aquatic marijuana and disease vector control, irrigation and also other human uses of normal water, downriver avalanche protection, entertainment (such while whitewater boating), and, of course , power era. From a great ecological standpoint, the ideal normal water release design would generally closely mimic the organic flooding regime (although it’s not always feasible for densely settled floodplains where avalanche protection is actually a high priority).

Dams that generate baseload electricity are typically more competent of replicating near-natural downriver flows than those that develop peaking electricity (where daily water emits may change sharply, as often as you can the detriment of aquatic organisms that are adapted to less repeated flow changes). Environmental supervision plans pertaining to hydroelectric assignments should identify environmental drinking water releases, including for public works owned or operated by private sector. Good Atteinte and Poor Dams your five

Major downriver hydrological alterations can destroy riparian ecosystems dependent on regular natural surging, exacerbate water pollution during lowflow periods, and increase deep sea intrusion around river mouths. Reduced crud and nutritious loads downriver of dams can increase river-edge and coastal chafing and damage the natural and economic productivity of rivers and estuaries. Caused desiccation of rivers beneath dams (when the water is usually diverted to one more portion of the river, in order to a different river) kills fish and other fauna and botánica dependent on the river, additionally, it may damage agriculture and human water supplies.

Mitigation Options Water-Related Diseases Some contagious diseases can spread around hydroelectric reservoirs, particularly in warm areas and densely populated areas. Some conditions (such while malaria and schistosomiasis) will be borne by simply water-dependent disease vectors (mosquitoes and marine snails), other folks (such as dysentery, cholera, and hepatitis A) will be spread simply by contaminated water, which usually becomes worse in stagnant reservoirs than it absolutely was in fast-flowing rivers.

Related public health steps should include preventive steps (such while awareness advertisments and home window screens), monitoring of vectors and disease outbreaks, vector control, and clinical remedying of disease circumstances, as required. Control of floating aquatic weeds (see below) near filled areas can reduce mosquito-borne disease hazards. Fish and Other Aquatic Lifestyle Hydroelectric projects often have significant effects about fish and other aquatic your life. Reservoirs efficiently affect certain fish species (and fisheries) by ncreasing the area of available aquatic habitat. However , the net impacts in many cases are negative since (a) the dam hindrances upriver fish migrations, although downriver verse through generators or over spillways is often unsuccessful, (b) a large number of riveradapted seafood and other marine species simply cannot survive in artificial lakes, (c) within downriver stream patterns detrimentally affect a large number of species, and (d) drinking water quality degeneration in or below reservoirs (usually low oxygen amounts, sometimes gas super-saturation) gets rid of fish and damages marine habitats.

Fresh water molluscs, crustaceans, and other benthic organisms are actually more sensitive to these changes than most fish kinds, due to their limited mobility. Administration of drinking water releases may be needed for the survival of certain fish species, in and under the reservoir. Fish passage features (fish ladders, elevators, or perhaps trap-and-truck operations) are intended to help migratory seafood move upriver past a dam, they are usually of limited effectiveness pertaining to various causes (including the issue of ensuring safe downriver verse for many adults and fry).

Fish hatcheries can be useful for retaining populations of native species which can make it through but not successfully reproduce inside the reservoir. Also, they are often used pertaining to stocking the reservoir with economically wanted species, even though introducing non-native fish is often devastating to native kinds and not ecologically desirable. Angling regulation is normally essential to keep viable masse of commercially valuable kinds, especially in the seas immediately beneath a atteinte where migratory fish kinds concentrate in high figures and are unnaturally easy to get.

Floating Aquatic Vegetation Floating aquatic vegetation can rapidly proliferate in eutrophic reservoirs, causing challenges such as (a) degraded environment for most species of fish and other aquatic your life, (b) increased breeding grounds pertaining to mosquitoes and also other nuisance species and disease vectors, (c) impeded navigation and going swimming, (d) blockage of electro-mechanical equipment in dams, and (e) increased water reduction from some reservoirs. Pollution control and pre-impoundment selective forest removing will make reservoirs less favorable to aquatic weed development.

Physical removing or hold of floating aquatic weeds is effective nevertheless imposes a high and repeated expense to get large reservoirs. Where suitable for other targets (power technology, fish success, etc . ), occasional drawdown of tank water levels may be used to get rid of aquatic weeds. Chemical poisoning of weeds or related insect pests needs much environmental caution which is usually best avoided. LCR Sustainable Creation Working Newspaper No of sixteen Environmental Affects (table goes on on next page) 6 Table 1 .

Hydroelectric Tasks: Adverse Environmental Impacts and Mitigation Alternatives (continued) Environmental Impacts Mitigation Options Lack of Cultural Real estate Cultural house, including archaeological, historical, paleontological, and religious sites and objects, could be inundated by reservoirs or destroyed simply by associated quarries, borrow starts, roads, or perhaps other functions. Structures and objects of cultural interest should undergo salvage exactly where feasible through scientific products on hand, careful physical relocation, and documentation and storage in museums or other ideal facilities.

However , it is often impossible to replace losing, or injury to, unique or perhaps sacred sites which may have great religious or etiqueta significance to indigenous or perhaps other local people. Reservoir Sedimentation Over time, live storage and power era are reduced by reservoir sedimentation, in a way that much of several projects’ hydroelectric energy is probably not renewable above the long term. In the event effectively executed, watershed supervision can decrease sedimentation and extend a reservoir’s beneficial physical your life, through the control over road construction, mining, agriculture, and other area use in the top catchment place.

Protected areas are sometimes proven in top catchments to lower sediment moves into reservoirs, as with the Fortuna Atteinte in Compared with and the recommended Rio Amoya (Colombia) and Nam Theun II (Laos) projects. Apart from watershed management, other crud management techniques for hydroelectric reservoirs may at times be literally and monetarily feasible, that they include, among others, upstream examine structures, protecting dam shops, reservoir flushing, mechanical removal, and raising the dam’s height.

Green house Gases Green house gas produces from reservoirs can be lowered by a thorough salvage of commercial timber and fuelwood, even though frequently that is not happen due to (a) large extraction and transportation costs, (b) marketing constraints, or (c) personal and monetary pressures to never delay reservoir filling. The surest way to minimize greenhouse gas emits from reservoirs is to choose dam sites that decrease the water damage of land in general, and forests specifically. table continues on pursuing page) Good Dams and Bad Public works 7 Green house gases (carbon dioxide and methane) happen to be released into the atmosphere by reservoirs that flood forests and other biomass, either slowly and gradually (as inundated organic matter decomposes) or rapidly (if the forest is slice and burned up before reservoir filling). Green house gases are widely regarded as being the main reason behind human-induced global climate transform. Many hydroelectric reservoirs overflow relatively little forest or perhaps other biomass.

Moreover, most hydroprojects generate sufficient electric power to much more than offset the greenhouse gases which will otherwise have been produced by using fossil fuels (natural gas, gasoline oil, or perhaps coal) in power vegetation. However , several projects which flood comprehensive forest areas, such as the Balbina Dam in Amazonian Brazil, appear to give off greenhouse fumes in increased amounts than would be produced by burning natural gas for many years of comparable electrical power generation. Minimization Options Impacts of Complementary Civil Performs Access Tracks

New access roads to hydroelectric dams can cause major property use changes” particularly deforestation”with resulting loss in biodiversity, accelerated erosion, and other environmental problems. In some tasks (such as Arun II in Nepal), the environmental affects of get roads can greatly surpass those of the reservoir. The siting of any fresh access streets should be in the environmentally and socially least damaging corridors. Forests and also other environmentally sensitive areas over the chosen highway corridor should receive legal and on-the-ground security.

Road architectural should guarantee proper drainage, to protect waterways and decrease erosion. Environmental rules intended for contractors (including penalties for noncompliance ) should cover construction camp siting, small extraction, garbage disposal, avoiding water quality, worker habit (such since no hunting), and other development practices. Find Ledec and Posas (2003) for specifics. Power Transmission Lines Power transmission line rights-of-way typically reduce and fragment jungles, indirectly, they occasionally assist in further deforestation by increasing physical access.

Large wild birds are sometimes slain in accidents with electric power lines, or by electric shock. Power lines can also be visually objectionable. Electrical power lines needs to be sited to reduce these worries and constructed using great environmental techniques (as with roads). In areas with concentrations of vulnerable parrot species, the most notable (grounding) cable should be produced more obvious with plastic-type material devices. Electric shock (mainly of large birds of prey) ought to be avoided through bird-friendly structure design and proper spacing of doing wires.

Quarries and Get Pits Quarries and acquire pits are more comfortable with provide material for building of the dam and supporting works. They can considerably increase the area of all-natural habitats or agricultural royaume that are shed to a hydroelectric project. For the greatest degree feasible, quarries and borrow pits needs to be sited inside the future inundation zone. Wherever this is not feasible, the starts should be rehabilitated after make use of, ideally for conservation functions such as wetland habitats. Affects of Induced Development

Linked Development Jobs Hydroelectric dams often make possible fresh development projects with major environmental affects, including irrigation, urban development, and production facilities (due to new drinking water supplies). New development tasks should be organized to minimize unfavorable environmental and social impacts. Environmental effect assessment research should be carried out in the early stages of project preparing, the resulting environmental mitigation plans needs to be fully implemented. Additional Dams

The construction from the first dam on a river can make the subsequent construction of additional dams cheaper, because circulation regulation by the upriver atteinte can improve power generation at the downriver dam(s). Environmentally friendly impact analysis study intended for the initial dam in any riv should include a cumulative environmental assessment in the likely impacts of proposed additional atteinte on the same water system. Implementation of minimization measures to get cumulative (rather than dam-specific) impacts must be completed or perhaps well underway prior to construction of the second dam on the river. LCR Sustainable Creation Working Daily news No of sixteen

Environmental Affects 8 Desk 1 . Hydroelectric Projects: Negative Environmental Impacts and Minimization Options (continued) Key Indications of Likely Environmental Influences 9. Ahead of a atteinte site is usually chosen (with a project-specific environmental effect assessment), sector-level environmental evaluation can ranking potential sites according for their degree of environmental desirability. A sectoral environmental assessment (SEA) should be completed prior to making major electric power sector organizing decisions, particularly in the comparison of hydroelectric and other electricity generation (and demand management) alternatives.

However , even without an in depth SEA, it is possible to carry out a simple environmental and ranking of different hydropower sites using basic, often easily available technical info. There can be found various quantitative, easily worked out indicators you can use to calculate the degree of adverse environmental effects for any suggested hydroelectric task. 10. This kind of paper reveals 13 quantitative, easily computed indicators that individuals consider especially useful for hydroproject site variety from an environmental standpoint. These symptoms have substantial predictive worth for probably adverse environmental (and related social) influences.

The initially nine symptoms (A”I) use information that is normally easy to attain from fundamental dam organizing data, without even a separate environmental study. The other four indicators (J”M) are also very important in the environmental comparison of substitute dam sites, but entail data that may require further environmental (or resettlement) study to obtain. Signal A (hectares of property inundated) is probably the single most successful one in predicting the degree of environmental damage, because indicator can be positively linked to many of the other folks.

From a social perspective, the number of persons requiring resettlement (Indicator J) is an especially important. A. Reservoir Surface Area 11. The area flooded by reservoir is a strong proxy variable for most environmental and social affects (Goodland, 1997). A large water tank area indicates the loss of very much natural environment and wildlife and/or the displacement of many people. Substantial reservoirs are typically in the lowlands (often with tropical disease and aquatic weed problems) and usually impound larger estuaries and rivers (with more fish and also other aquatic species at risk).

A very useful way of measuring environmental costs relative to financial benefits is the ratio of inundated hectares per megawatt (ha/MW) of electricity, that varies simply by four orders of size for large power jobs (see Table 2). A global average for any large hydroelectric dams made to date (not just all those in Table 2) is about 60 ha/MW (J. Goldemberg, pers. comm. ), it might be environmentally extremely desirable with this average being much lowered in future hydroprojects. B. Water Retention Time in Water tank 12.

Indicate water retention time during normal operation (the shorter, the better) is very useful in price the degree to which reservoirs will have long lasting water quality problems. This figure (number of days) is calculated as a function of tank volume (cubic meters) and mean water flow (cubic liters per second). being unfaithful 10 LCR Sustainable Advancement Working Newspaper No . of sixteen C. Biomass Flooded 13. Biomass bombarded is determined in loads per hectare based on the percent cover of different vegetation types inside the reservoir location.

For good water tank water quality, dams will need to minimize water damage of forests (which have high biomass content). Surging native woodlands also threatens biodiversity and releases greenhouse gases. D. Length of River Impounded 16. To conserve aquatic and riparian biodiversity (including riverine forests), dam sites should decrease the length (kilometers) of riv (main come plus tributaries) impounded by reservoir (measured during high flow periods). Elizabeth. Length of Lake Left Dry out 15. This kind of measures the kilometers of river kept dry (with less than 50 % of dry out season imply flow) under the dam, due to water curve.

The length of dried-up river bed (before the next important downstream tributary) ought to be minimized, because of the loss of fish and other aquatic life, problems for riparian ecosystems, and dysfunction of man water supplies, agriculture, and fishing. F. Number of Downriver Tributaries 18. The more (major, undammed) tributaries downriver of the dam site, the better, in terms of retaining accessible environment for migratory fish, the natural flooding regime pertaining to riverine environments, and nutrient or residue inputs required for the large biological productivity of estuaries. G. Probability of Reservoir Stratification 7. Couche in a water tank occurs when the lake’s upper sector (epilimnion) is usually thermally divided from the much deeper zone (hypolimnion), the latter turns into stagnant and lacking in mixed oxygen (anaerobic), thereby unsuitable for most aquatic life. A rapid estimate of stratification traits in a reservoir can be obtained while using Densimetric Froude Number (F). F can be calculated as: F sama dengan 320(L/D)(Q/V), exactly where L = length of the water tank (meters), G = suggest reservoir depth (meters) (for which dam height can be quite a proxy), Queen = imply water inflow (cubic metres per second), and Sixth is v = eservoir volume (cubic meters). In the event that F is less than 1, several stratification is expected, the severity which increases using a smaller F. When F is more than 1, couchette is not going. H. Useful Reservoir Existence 18. Valuable reservoir a lot more the expected number of years ahead of a reservoir’s dead storage area is completely packed, so that further sedimentation reduces the live storage and curtails electric power generation. Useless storage includes all reservoir water underneath the level of the intakes to get the dam’s turbines, each of the water at or above this consumption level is usually part of the live storage.

Valuable reservoir life is a function of dead storage area and river-borne sediment tons. Useful reservoir life is a great indicator of the relative durability of electric electric power generation, that varies from below ten years before dead safe-keeping is filled (such as the Paute Dam in Ecuador) to probably thousands of years. In general, reservoirs with all the longest useful life will be relatively profound and located on waterways with low sediment lots. Maintaining low sediment loads over time typically requires good watershed administration. Good Dams and Bad Dams 10 I. Get Roads through Forests nineteen.

Where the dangers of caused deforestation will be high, task siting should minimize the kilometers of required fresh or upgraded access highways passing through or near natural forests. M. Persons Necessitating Resettlement twenty. The number of people physically displaced by hydroelectric projects varies from no (e. g. Pehuenche, Chile) to over 60, 000 in Latin America (e. g. Yacyreta, Argentina-Paraguay) and more than 1 , 000, 000 in Asia (Three Gosier, China). Atteinte siting ought to generally strive to minimize the amount of individuals or perhaps households demanding resettlement by lands afflicted with the reservoir and contrasting civil performs.

A useful evaluate for relating resettlement costs to hydropower benefits may be the ratio of individuals displaced per megawatt (Table 2). Due to their usually higher vulnerability to social dysfunction, it is particularly significant to minimize the quantity of indigenous people who have traditional land-based models of production who would need resettlement. E. Critical Organic Habitats Influenced 21. It is necessary to know the amount of sites and hectares of critical natural habitats that might be lost to inundation, get pits, or perhaps other project components.

Critical natural refuge include existing and officially proposed shielded areas, and also unprotected areas of known substantial importance for biodiversity conservation. To abide by the World Bank’s Natural G?te Policy, hydroelectric projects should never cause virtually any significant reduction or wreckage of important natural refuge. On the other hand, some hydroelectric jobs imply very important conservation chances by providing a solid justification (sediment reduction) and financial resources required for protecting organic habitats in upper catchment areas.

L. Fish Kinds Diversity and Endemism 22. Fish species diversity is definitely the number of types known through the project location, including the dam and water tank site, in addition to the downstream sector of project influence. Fish species endemism is the number of native kinds known from the task area, or maybe the river system where the project is located, and nowhere else on Earth. Atteinte are ecologically less objectionable if they will affect waterways with a obviously low variety and endemism of native fish species.

In general, large, lowland streams in warm (tropical or subtropical) weather have a top diversity of native fish and other aquatic organisms, although small waterways in cold (tropical highland or temperate) climates include relatively low diversity. Large, lowland streams are also very likely to have significant seasonal seafood migrations, which are effectively obstructed by most dams. However , highland rivers and channels often have comparatively high endemism in their seafood fauna, especially if they are remote from other waterways by waterfalls or additional natural limitations.

River portions with threatened fish species found nowhere fast else should be classified as critical natural habitats and, ideally, will receive long term protection from atteinte or different potentially damaging civil works. However , atteinte and reservoirs in higher tributary waterways and avenues need not threaten the your survival of virtually any endemic fish (or mollusks, or additional aquatic life) if they will affect only an unimportant portion of the river region used by these species (see Indicators G and E), they should become sited so as not to block important fish migrations. Meters. Cultural Real estate Affected twenty three.

An indication with the cultural value of the area to be bombarded (or in any other case affected by the project) is a number (by type) of cultural (archaeological, historical, paleontological, or religious) objects or perhaps sites. It is important to note whether each type of cultural property at the job site is salvageable (totally, partially, or not at all). 12 LCR Environmentally friendly Development Working Paper Number 16 Table 2 . Property Area Flooded and People Out of place in Huge Hydropower Tasks Project (country) Arun II (Nepal) Pehuenche (Chile) Pangue (Chile) Guavio (Colombia) Tehri (India) Ghazi Barotha (Pakistan)

Nam Theun-Hinboun (Laos) Ertan (China) Fortuna (Panama) Chixoy (Guatemala) Grand Coulee (United States) Three Gorges (China) Tarbela (Pakistan) Salvajina (Colombia) Zimapan (Mexico) Itaipu (Brazil/Paraguay) Victoria (Sri Lanka) Kararao/Belo Monte (Brazil) Aguamilpa (Mexico) Betania (Colombia) Urra I actually (Colombia) Mangla (Pakistan) Bakun (Malaysia) Ataturk (Turkey) Un Cajon (Honduras) Ilha Solteira (Brazil) Guri Complex (Venezuela) Salto Grande (Argentina/Uruguay) Nam Theun II (Laos) Arenal (Costa Rica) Yacyreta (Argentina/Paraguay) Tucurui (Brazil) Narmada Sagar (India) Porto Primavera (Brazil)

Churchill Falls (Canada) Khao Laem (Thailand) Kedung Ombo (Indonesia) Kainji (Nigeria) Pak Mun (Thailand) Cabora Bassa (Mozambique) Aswan High (Egypt) Nam Ngum (Laos) Sobradinho (Brazil) Kariba (Zambia/Zimbabwe) Balbina (Brazil) Akosombo (Ghana) Bayano (Panama) Kompienga (Burkina Faso) Brokopondo (Suriname) Installed capability (MW) 402 500 400.00 1, 500 2, 4 hundred 1, 450 210 three or more, 300 three hundred 300 6th, 494 18, 200 three or more, 478 270 280 doze, 600 210 8, 381 960 510 340 you, 000 two, 400 a couple of, 400 three hundred 3, 200 10, three hundred 1, 890 1, 086 157 3, 100 a few, 980 1, 000 one particular, 815 a few, 225 300 29 760 34 a couple of, 075 a couple of, 100 a hundred and fifty 1, 050 1, 260 250 833 30 16 30 Water tank rea (hectares) 43 4 hundred 500 1, 530 4, 200 a couple of, 640 630 10, 100 1, 050 1, 400 33, 306 110, 1000 24, 280 2, 030 2, three hundred 135, 1000 2, 270 116, 1000 13, 000 7, 370 7, four hundred 25, three hundred 70, 000 81, seven hundred 11, 2 hundred 125, seven hundred 426, 1000 78, three hundred 45, 000 7, 500 165, 000 243, 1000 90, 820 225, 500 665, 1000 38, 800 4, six hundred 126, 000 6, 1000 380, 000 400, 1000 37, 1000 415, 000 510, 500 236, 000 848, two hundred 35, 500 20, 500 160, 000 People out of place 775 0 50 5, 959 75, 000 899 0 35, 000 446 3, 445 10, 1000 &gt, 1, 300, 500 96, 000 3, 272 2, 800 59, 500 45, 000 n. a. 1, 000 544 6th, 200 80, 000 9, 000 55, 000 some, 000 6th, 150 1, 500 and. a. 5, 700 a couple of, 500 50, 000 30, 000 80, 500 15, 000 zero 10, 800 29, 000 50, 000 4, 945

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