Ecological Impacts of Ecological Impacts of DamsDams

Lora StoyanovaLora StoyanovaViara TzvetkovaViara TzvetkovaGoran GeorgievGoran Georgiev

10/310/3

Impact on FishesImpact on Fishes

Dams obstruct fish movement, Dams obstruct fish movement,

especially their migration. especially their migration.

This can have a great influence This can have a great influence

on the fish population in the area.on the fish population in the area.

Very bad ecological impact for species such Very bad ecological impact for species such

as bears (1)as bears (1)

http://blog.mlive.com/chronicle/2008/04/07deadfish.jpg

Water QualityWater Quality

Water becomes still Water becomes still

with little to no flow of new with little to no flow of new

water – gather of pollution.water – gather of pollution. Alters water’s natural seasonal Alters water’s natural seasonal

temperatures – affects oxygen levels and temperatures – affects oxygen levels and chemical reactions.chemical reactions.

Huge amounts of water evaporates.(2)Huge amounts of water evaporates.(2) Release of pesticides which contaminate Release of pesticides which contaminate

water. water.

http://upload.wikimedia.org/wikipedia/commons/8/8b/Dam_with_water.jpg

Water Quality - CarbonWater Quality - Carbon

Still water stores and releases a lot of Still water stores and releases a lot of carbon.carbon.

Vegetation starts to rot also releasing a Vegetation starts to rot also releasing a lot of carbon as well as other lot of carbon as well as other greenhouse gases such as methane.greenhouse gases such as methane.

Carbon is both an air and water Carbon is both an air and water polluting agent.polluting agent.

Stored carbon forms organic pesticides Stored carbon forms organic pesticides which start killing the river’s species (5)which start killing the river’s species (5)

Loss of SedimentLoss of Sediment

Water flow stops making the sediment Water flow stops making the sediment sink to the bottom of the reservoir (4)sink to the bottom of the reservoir (4)

Overtime the sediment builds up, which Overtime the sediment builds up, which rises water levels and puts pressure on rises water levels and puts pressure on dam walls.dam walls.

The dam might not be able to hold up and The dam might not be able to hold up and can eventually bursts with the water can eventually bursts with the water flooding towns and killing people. flooding towns and killing people.

There is no way of removing this There is no way of removing this sediment. (1)sediment. (1)

Impact on PeopleImpact on People

Dam bursts because of sediment can Dam bursts because of sediment can lead to hundreds of death and lead to hundreds of death and destruction. (1)destruction. (1)

The side of the dam with less water, The side of the dam with less water, famers struggle to keep their crops, etc. famers struggle to keep their crops, etc. alive.alive.

Fisherman suffer the reduction of fish Fisherman suffer the reduction of fish greatly and must fish next to the dam or greatly and must fish next to the dam or simply move out (3).simply move out (3).

Three Reasons for DamsThree Reasons for Dams

Agriculture, irrigation, and water supplyAgriculture, irrigation, and water supply EnergyEnergy Flood managementFlood management

Water can be saved, not wastedWater can be saved, not wasted Better irrigation systems (40% of the food is Better irrigation systems (40% of the food is

gotten from 17 % of irrigated land)gotten from 17 % of irrigated land) Better water harvesting techniquesBetter water harvesting techniques Better energy efficiencyBetter energy efficiency Renewable sources of energy (wind, sun, Renewable sources of energy (wind, sun,

etc)etc) IRBM- IRBM- Integrated river basin management  Integrated river basin management 

Managing, developing, and conserving the Managing, developing, and conserving the use of water and land within a river basinuse of water and land within a river basin

SSustainable use of freshwater resources ustainable use of freshwater resources PPreventing disastrous floodsreventing disastrous floods (12) (12)

Changed Environmental Changed Environmental Requirements Requirements

Aerial photography and photogrammetryAerial photography and photogrammetry Streamflow measurement and yield Streamflow measurement and yield

estimationestimation Flood hydrologyFlood hydrology Spillway, diversion and outlet hydraulicsSpillway, diversion and outlet hydraulics Geotechnical investigationsGeotechnical investigations Site selectionSite selection Selection of dam type and layout (13)Selection of dam type and layout (13)

Dam Risk AssessmentDam Risk Assessment

Identification of potential hazardsIdentification of potential hazards Assessment of risk by assigning Assessment of risk by assigning

probabilities to failure modesprobabilities to failure modes Dam break modelling (1 and 2 Dam break modelling (1 and 2

dimensional)dimensional) Identification of unacceptable risksIdentification of unacceptable risks Investigation of appropriate risk Investigation of appropriate risk

reduction measures (13)reduction measures (13)

ExamplesExamples Aral SeaAral Sea •Three Gorges Dam

http://shipbright.files.wordpress.com/2009/08/aral_sea_1989-20081.jpg http://www.indraz.net/wp-content/uploads/2008/02/3gorges-before-and-during.jpg

Aral SeaAral Sea Location: between Location: between

Kazakhstan and UzbekistanKazakhstan and Uzbekistan Since 1960- shrank a lotSince 1960- shrank a lot ImpactImpact

in depth- more than two times in depth- more than two times less in 20 yearsless in 20 years

in width- a tiny water basin in in width- a tiny water basin in the western part (11)the western part (11)

http://maps.grida.no/go/graphic/shrinking_of_the_aral_sea_socio_economic_impacts

• Socio-economic and Ecological Impact- A former fishing zone is now

dry => many fishermen lost their jobs- Different crops are now grown (cotton and rice)- The remaining of the Aral sea- very polluted from drainage

water- Increased salinity => only one of the 20 living species in the

Aral sea survived (8)

Reason and SolutionReason and Solution

Reason- rivers flowing Reason- rivers flowing into the Aral Sea were into the Aral Sea were diverted by the Soviet diverted by the Soviet UnionUnion Result- water supply to the Result- water supply to the

Aral sea: cut off (10)Aral sea: cut off (10) ImprovementImprovement

a dam createda dam created for 2 years- level increased for 2 years- level increased

with 12 meter (9)with 12 meter (9)

http://www.orexca.com/aral_sea.shtml

Three Gorges DamThree Gorges Dam

Location: Eastern ChinaLocation: Eastern China World’s largest electricity- World’s largest electricity-

generating plantgenerating plant Reasons: mostly Reasons: mostly

economical, not concerning economical, not concerning environmentenvironment To produce electricityTo produce electricity Flood Control (15)Flood Control (15)

http://www.arch.mcgill.ca/prof/sijpkes/arch374/winter2001/dbiggs/chinamap.gif

ImpactImpact Advantages of dam Advantages of dam

createdcreated Reduces chances of flood Reduces chances of flood

(controls water levels)(controls water levels) Provides electricityProvides electricity NavigationNavigation

Disadvantages Disadvantages Causes ecological changesCauses ecological changes During the process of During the process of

building- a lot of floodsbuilding- a lot of floods Very expensiveVery expensive In order to be built, many In order to be built, many

people moved away (14)people moved away (14)

Works CitedWorks Cited1.1. "The Effects of Dams." "The Effects of Dams." Stream Biology and EcologyStream Biology and Ecology. Web. 9 June 2010. . Web. 9 June 2010.

<http://chamisa.freeshell.org/dam.htm>. <http://chamisa.freeshell.org/dam.htm>. 2.2. McCully, Patrick. "Dams and Water Quality." McCully, Patrick. "Dams and Water Quality." International RiversInternational Rivers. Web. 8 June . Web. 8 June 2010. 2010.

<http://www.internationalrivers.org/en/node/1638>. <http://www.internationalrivers.org/en/node/1638>. 3.3. Mirand, Ane. "Dams Cutting Off 400 Million People From Food and Income «." Mirand, Ane. "Dams Cutting Off 400 Million People From Food and Income «." Peak WaterPeak Water. 05 June . 05 June

2010. Web. 9 June 2010. 2010. Web. 9 June 2010. <http://peakwater.org/?p=1526>. <http://peakwater.org/?p=1526>. 4.4. "Sedimentation Problems with Dams." "Sedimentation Problems with Dams." International RiversInternational Rivers. Web. 9 June 2010. . Web. 9 June 2010.

<http://www.internationalrivers.org/en/node/1476>. <http://www.internationalrivers.org/en/node/1476>. 5.5. "Tillegra Dam to Pump out CO2." "Tillegra Dam to Pump out CO2." Carbon Offsets DailyCarbon Offsets Daily. Web. 9 June 2010. . Web. 9 June 2010.

<http://www.carbonoffsetsdaily.com/news-channels/australasia/tillegra-<http://www.carbonoffsetsdaily.com/news-channels/australasia/tillegra- dam-to-pump-out-dam-to-pump-out-co2-21892.htm>. co2-21892.htm>.

6.6. "Water Quality." "Water Quality." KenyonKenyon. Web. 8 June 2010. . Web. 8 June 2010. <http://www2.kenyon.edu/projects/Dams/beb01coa.html>. <http://www2.kenyon.edu/projects/Dams/beb01coa.html>.

7.7. "Why Are Dams Potentially Harmful to Fish?" "Why Are Dams Potentially Harmful to Fish?" WiseGEEK: Clear Answers for WiseGEEK: Clear Answers for Common QuestionsCommon Questions. . Web. 8 June 2010. <http://www.wisegeek.com/why-Web. 8 June 2010. <http://www.wisegeek.com/why- are-dams-potentially-harmful-to-fish.htm>. are-dams-potentially-harmful-to-fish.htm>.

8.8. "Aral Sea Disaster – Cause and Effect « All That Is Manfred." "Aral Sea Disaster – Cause and Effect « All That Is Manfred." All That Is ManfredAll That Is Manfred. Web. 15 June 2010. . Web. 15 June 2010. <http://allthatismanfred.wordpress.com/2009/09/30/aral-sea-disaster-cause-and-effect/>. <http://allthatismanfred.wordpress.com/2009/09/30/aral-sea-disaster-cause-and-effect/>.

9.9. Antelava, Natalya. "Dam project aims to save Aral Sea". BBC MMX. 8/06/010 Antelava, Natalya. "Dam project aims to save Aral Sea". BBC MMX. 8/06/010 <http://news.bbc.co.uk/2/hi/asia-pacific/6538219.stm>.<http://news.bbc.co.uk/2/hi/asia-pacific/6538219.stm>.

10.10. "The History of the Aral Sea". OrexCA. 8/06/2010 <http://www.orexca.com/aral_sea.shtml>."The History of the Aral Sea". OrexCA. 8/06/2010 <http://www.orexca.com/aral_sea.shtml>.

11.11. Lambroschini, Antoine. "Aral Sea Revived by Dam". Discovery Communications, LLC. 8/06/2010 Lambroschini, Antoine. "Aral Sea Revived by Dam". Discovery Communications, LLC. 8/06/2010 <http://dsc.discovery.com/news/2008/06/24/aral-sea.html>.<http://dsc.discovery.com/news/2008/06/24/aral-sea.html>.

12.12. "WWF - Dam Solutions - Flood Management." "WWF - Dam Solutions - Flood Management." WWF - WWFWWF - WWF. Web. 15 June 2010.. Web. 15 June 2010. <http://wwf.panda.org/what_we_do/footprint/water/dams_initiative/dams/floods/>.<http://wwf.panda.org/what_we_do/footprint/water/dams_initiative/dams/floods/>.

13.13. "Dams Capability." "Dams Capability." Hydro Tasmania ConsultingHydro Tasmania Consulting. Web. 15 June 2010.. Web. 15 June 2010. <<http://www.hydrotasmaniaconsulting.com/files/00526-Dams-Capability.pdhttp://www.hydrotasmaniaconsulting.com/files/00526-Dams-Capability.pdf>. f>.

14.14. "Benefits from Three Gorges Dam". Travel China Guide. 8/06/2010"Benefits from Three Gorges Dam". Travel China Guide. 8/06/2010 <http://www.travelchinaguide.com/attraction/hubei/yichang/three-gorges-dam-project.htm>. <http://www.travelchinaguide.com/attraction/hubei/yichang/three-gorges-dam-project.htm>.

15.15. O’Hara, Laura. “The Three Gorges Dam Project”. 8/06/2010 <http://www.mtholyoke.edu/~lpohara/>.O’Hara, Laura. “The Three Gorges Dam Project”. 8/06/2010 <http://www.mtholyoke.edu/~lpohara/>.