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Topic 24: Safety in Hydropower

RossWinter's picture

The biggest disaster in terms of fatalities in the energy industry was the 1975 Banqiao Dam failure in China which killed over 170,000 people. However this is not the only hydroelectric dam failure which has cause loss of life and major damage in the surrounding area. The accidents in this sector are rare but when something does go wrong then the consequences are usually fatal. Planners need to take a lot of geological and environmental issues into account when they plan building new hydroelectric plants but sometimes the events can’t be predicted.

How extreme events should be predicted in building these dams?

Ross Winter



RossWinter's picture

Hydropower incidents are usually cause by 3 main factors; poor planning, unpredictable natural events or equipment failure.Sometimes developers of new dams don’t take all geological factors into account, this was the case in the 1963 Vajont Dam disaster in Italy. It was cause by a tidal wave overtopping the dam and flooding the valley below, killing around 2500 people. The wave was cause by a the water in the dam eroding the rock, causing a landslide and this created a massive wave, which didn’t destroy the dam, but swept down the valley completely destroying several towns on its way.The Banqiao Dam was cause by a typhoon which cause the areas yearly precipitation levels in a few hours which no-one would have predicted happening. Another dam failure cause by unpredictable natural causes was the Kyzyl-Agash dam failure in Kazakhstan. In 2010 the dam burst due to increased rainfall and early snowmelt due to unseasonably warm weather, this incident killed at least 43 people but some figures quoted are over 200 people. Could these deaths have been predicted, it is hard to tell because of the severity of the water rises over prediction. It is hard to make previsions for events on this scale without spending millions more than needed.

Ross Winter Msc Renewable Energy

Fungisai N Nota's picture

Fungisai Nota BEng(Hons) MIET

Fungisai N Nota's picture

Fungisai Nota BEng(Hons) MIET

Fungisai N Nota's picture

 Adding to what Ross has said I do believe that it is down to
unexpected events and poor construction that can lead to major disasters within
the hydropower industries. There should be due diligence and the right
assessment carried out before constructing a dam or a hydro-plant that is will
it withstand the capacity that will flow and in the event of natural disasters
what measure are there to cope with the extra pressure like the disasters in
chine we so that there was no measures in place and the dam walls were poorly constructed
and hence leading to the deaths of many people.  

Fungisai Nota BEng(Hons) MIET

Maria Christou's picture


I agree with Ross above that hydropower might hide some
risks which lead to a disaster; however hydropower in general is considered to
be one the safest sources of power. First of all, hydroelectricity is a
renewable source of energy since it only uses water to generate electricity. In
addition to that, the usage of fuel is not necessary which means that
hydropower does not emit greenhouses gases and it does not pollute the environment;
it provides us with fresh air. Plus, hydropower has low operating costs and it
requires little maintenance. We can definitely say that hydropower promises a
better future.

What is important is that people need to learn how to manage
the hydropower in order to improve their quality of life and keep the environment





It is true that hydropower does not produce greenhouse gases and does not create pollution directly,
it still does have a number of detrimental effects on the environment. The
activities involved in the construction of the dam disrupt the environment on a
large scale. When the course of water is changed the surrounding areas may get
flooded disturbing natural flora and fauna. The large quantities of water
collected due to the flood emit a lot if GHG like carbon dioxide. Also talking
about maintenance not so slightly expensive, you have to put in consideration
that the average dam in the world is about 30 years of age and these dams get
weak. So you are looking at an increase in the safety checks of these old dams,
which obviously costs more money.


Okechukwu Chukelu (51231798)

Richard Sedafor's picture


Maria, even though Dams do not produce direct emissions like coal, oil and gas plants, the production of materials used in the construction of these dams and the construction phase itself produces emissions. Therefore if you analysing the Life-cycle of the Hydroplant you will realize that it is not soo clean as it may appear. With regards to deaths per KWh energy produced, Hydropower is relatively safer than Coal, peat, oil and gas sources of energy. The death per KWh for Hydropower is estimated at 1.4 world wide.[1]

More alarming is the social impacts that are associated with Dam construction and its related activities. Displacement and its associated risks are a concern to every society. WCD(2000) reports that about 40 to 80 million people have been displaced as a result of dam construction.[2]. This displacements often have the consequence of impoverishment, hunger and even death.

Who are we preventing effects of greenhouse emissions from? Isnt it humans and wild life? If it is, then hydropower is not soo safe looking at it in totality.


Richard Sedafor.

Msc Oil and Gas Engineering.




[3]WCD (world Commission on Dams) Dams and Development, Earthcan, 2000



It’s very risky
to have hydropower plant around human population especially in seismic active areas. Of
recent have been seismic activities recorded five tremors with the strongest
one measured at 4.2 on the Richter scale (culled from
near Song Tranh 2 hydropower plant in Quang Nam Province. Although the tremors
did not affect the dam and the plant is still running normally, what happens if
there is another earthquake? Its been said so far that each one is always
stronger than the other even though the latest one did nothing to the dam,
previous ones had left cracks and leaks in the hydropower plant. These earthquakes
cannot be controlled by man, they happen whenever they want to. When you have a
population of 30,000 people living in the downstream area of Song Tranh 2
hydropower plant, I really think having a hydropower plant is a bad idea unless
you have measures in place on how to detect these earthquakes way before they
happen and have a plan on how to relocate these people if the worst thing


Okechukwu Chukelu (51231798)

Harrison Oluwaseyi's picture

The science behind hydropower or
hydroelectricity as it recently called now involves transferring the energy in
moving water for more useful reasons. This  principle has been used from the ancient days
for agricultural purposes(irrigation)  and
the movement of mechanical devices(mills, lifts, water clocks).Hydroelectricity
as the name signifies involves transfer energy from moving water to generate
electricity for domestic and industrial uses.

Hitherto electricity has been
generated from moving water through the use of dams. The earliest dams constructed
were for agricultural uses, water storage, and domestic uses. A dam is a large
barrier in the path of a body of flowing water, river. These barriers could be
made of different materials (timber, concrete, steel).A water dam is used to
generate electricity by using the potential energy in the moving or dammed
water to drive a turbine and the generator.

 This form of energy generation technique
releases no green houses and is considered one of the cleanest forms of energy,
but the water released back to the environment has caused more harm than good. According
to recent studies which blame major dam accidents on faulty construction,
natural disasters, life time of dam etc. Several accidents have occurred in this
field that has changed the dams are designed and located.

Examples of these events include:

1) 2009, Russia,
Sayano-Shushenskaya Dam, 75fatalities. (Turbine failure)

2) 1975, China, Banqiao Dam,
171,000fatalities (flooding, famine and epidemics). (dam failed as a result of overtopping)

3) 1956, USA, Schollkopf Power
Station, 1fatality, cost $100million. (Destruction of the plant).

4) 2000, Switzerland, Bieudron
Hydroelectric Power Station, 3fatalities, flooding and loss of generating
capacity. (Penstock rupture)  

About seven dam failures have occurred
till date, there has been only one case where the dam failed as a result of
natural disaster. Most of the other disasters occurred as a result of mechanical
failure of the turbine or overtopping of the dam. The solution to these problems
should be tackled by improving and adhering to the regulations of dam
construction and maintenance policies. The earth we live on is covered by 70% water;
I believe we should make use of this advantage by using water to generate more








Like my colleagues have already said,hydro power is one of the safest and reliable renewable source of energy unlike other energy sources.It may not be 100% safe  but as Harrison has already noted,most of the accidents associated with hydro power are due to equipment failures and poor maintenance practices and these should be blamed on human negligence/errors during the design,construction and maintenance of hydro power stations.I still beleive that it is very possible to acheive maximum safety in hydro power stations if proper safety procedures and regulations are adhered to.About the flooding that  Okechukwu Chukelu is talking about,i think this can be avoided by a proper design of the dam and i dont see any carbondioxide emissions coming out of a hydropower plant because water just runs through the turbines,it is not effluent  neither is there a combustion process however they do have some impact on the  environment  through damming ,diversion and or hydro-peaking (1). Since dams and weirs  interrupt the flow of streams ,they act as barriers restricting fish from reaching their spawn areas especially salmon.There fore dams affect the feeding habits of fish.Also the natural transport of sediments is altered (1).Other impacts of hydro power is the change of land scape and creation of reservoirs  that act as breeding places for mosquitoes which cause malaria to  humans. Most of the above safety and environmental concerns can however be mitigated or avoided by ensuring proper planning before the construction process of the dams. 

It should however be noted that Hydro power plants are even much safer than the other renewable sources of energy and present a very bright future.


John Bosco Aliganyira

Msc.Oil and Gas Engineering


energy improved, sustainable and clean options for our planet by
T. M
Letcher (Trevor M.); c2008

sreehariprabhu's picture

In our ever increasing demand of world, hydro power is one of the main source of production of electricity. Also it is a renewable energy and thus doesn't cause any pollution. Eventhough the hydro power is safer than fossil fuel systems and nuclear systems, still a lot of safety aspects are needed to be considered. As demand for electricity rises and falls throughout each day, operators
stationed many kilometres away open and close dams, and start and stop
generating units as needed. This results in frequent and rapid changes
in water levels and flows around our facilities, changes that can
affect the safety of people living nearby. A spot that looks calm and safe one moment can become dangerous
within a few seconds as water levels and flows change, often without
warning. Calm waters or a dry riverbed could change quickly into one
with rapidly moving, dangerous waters. So it is important to set signs where the water may rise and people should take care of going beyond the signs for safety.

Other safety measures include the design of the dams. These dams should be safely designed by considering all loads and stresses. Even after the construction is complete, it is very important to frequently inspect the dams. Often, it is the lack of inspection of dams which turns to be a factor leading to unfortunate incidents.



Sreehari Ramachandra Prabhu

Andreas Kokkinos's picture

Hydropower is among the most
significant sources of exploiting energy falling from water used mainly for
electricity production but also for other purposes such as operation of
mechanical devices. The major issue associated with hydropower is the failure
risks of water dams or hydropower stations. [1] The most notable incident
globally is the Benqiao Dam disaster in China where 26,000 people were killed
from direct flooding and other 145,000 people dead from famine and epidemics. Another
very important incident was the Sayano – Shushenkaya Dam disaster in Russia
where 75 people were killed and 6GW of power generation was lost due to turbine
failure. [1]

There are multiple reasons for
causing a water dam or a hydropower station to fail. The most significant are
inappropriate planning, poor design and improper construction. Besides that, the
number of fatalities in such incidents tends to increase when these stations and
dams are constructed near residential or highly dense locations in which the residents
may not have the time to react. Additionally, landslide in an extremely
dangerous event for water dams because may result in disaster. Such event occurred
in Italy in 1963 when a landslide in the Vaiont Dam generated tidal which overflowed
the dam killing over 2000 people. [2]



Andreas Kokkinos

MSc Oil and Gas Engineering

faizakhatri's picture

Though the hydroelectric power plants do not require any fuel, don’t produce greenhouse gases and don’t create pollution directly, it does have a number of detrimental effects on the environment. The construction activity of the dam itself disturbs the environment to a great scale.When the course of water is changed the surrounding areas may get flooded disturbing natural flora and fauna. Human beings living in these areas also get displaced. The large quantities of water collected due to the floods also emit a lot of greenhouse gases like carbon dioxide. Thus though the hydroelectric power plants don’t generate greenhouse gases directly, they generate it indirectly. it is important  for take  safety in first place when plant is constructed and  Commission's hydropower  as a top priority. Before projects are constructed, the Commission staff reviews and approves the designs, plans, and specifications of dams, powerhouses, and other structures. During construction, Commission staff engineers frequently inspect a project, and once construction is complete, after that it also  continue to inspect it on a regular basis  to keep life and the environment safe 

Igwe Veronica Ifenyinwa's picture

Hydropower is considered the most energy efficient means of
power generation because it’s capable of converting majority of the available
energy into electricity unlike fossil fuel plant whose efficiency is about

Hydro power does not release dangerous emissions. it is
clean, green and renewable which means that if it is well controlled it will
have zero impact on the environment and it also has very low operating cost
when compared to other means of power generation. Its hydrological cycle is
being driven by the energy from the sun, with uninterrupted renewable supply of
water. The water used to for hydropower generation can also be reused.


Craig Donaldson's picture

I disagree, even if the design of a dam is controlled and monitored closely it cannot have zero impact on the environment. The very fact that you are creating a dam means that a lake will form behind it and is often overlooked when people think about hydropower. This new lake has to form on something which could be land used for farming or effect whole ecosystems upstream. The river which the dam is placed on will be affected and as mentioned before fish, which use the river as a migratory path will be substantially disturbed. However, it is unlikely these days that a dam would be placed someone which would require a large relocation of a human population.

I believe this striking picture of the Merowe Dam in Sudan highlights the problem.

Marinos Ioannou's picture

Inside Hydropower
facilities or near them a lot of dangerous conditions may exist. The project
structures and operations may cause drowning, accidental deaths and injuries.
The Federal Energy Regulatory Commission (FERC)
and project owners and managers are concerned with this hazard issues and they
try to limit the risk probabilities.  Law enforcement agencies and local
authorities deal with all the other probable hazard issues that are not
associated with project structures or operation. Risks like these have to be
considered also in personal level, because everyone who gets close to the
facilities has to know and understand the risk issues that he/she may deal with.

Marinos Ioannou

Trevor Strawbridge's picture

This is a sustainable energy source. Even though there have been some major disasters in the Hydro power sector these have been attributable to poor design, poor geological survey or poor site selection or even a combination. Norway is a major producer of North sea gas and exports 80% of this to the UK and other neighbouring countries. The reason for this is that the majority of Norways energy is produced from Hydro power. Currently in the UK, North Wales Power have been developing and indeed generating hydro electicity for some years. They adopt 2 methods namely "High head" & " Low head". Low head is a method traditionally associated with Dams, but High head uses diverted natural flow of mountain side water through pipes that have turbine constructions within. Both of these methods use enviromentally friendy techniques but the consequences of failure for either method differ by far. However so long as the risks are managed in this sector and the facilities maintained for the design life and decommisioned appropriately thereafter; this is a genuine power source. The Hydropower plant in Snowdonia North Wales is open to the public , its a beautiiful part of the country. I would recommend a visit

The first house in the world powered by Hydroelectric

Frixos Karletides's picture

A hydropower project has
the ability to use the water’s momentum and generate electricity. It is a clean
renewable energy and does not produce any greenhouse gases or harmful waste
during its operation. The construction process of such a project is very
demanding and takes a lot of time to finish since it involves significant
risks. Special care in every construction phase is needed due to the fact that
a dam failure can result to momentous consequences. A hydropower dam can be
very dangerous since the smooth river water can change instantly when a turbine
starts or a spillway opens. These changes can affect the safety of people who
are nearby since eddies sudden changes in water level can be formed. It is
important for people to know the potential dangers near a hydropower river or


Frixos Karletides

Angelos Hadjiantoni's picture

Dear Frixos,

I totally agree with you that care must be taken when constructing dams which is the case for every operation in the power industry.
 Moreover studies should be carried out regarding possible side effects.
But I would like to add to the discussion the fact that hydropower is not the dangerous energy source that some people present it to be.
To support my opinion I am including here a figure taken by the “Sunstainable Energy- without the hot air” by JC McKay.

From the graph above we can see that hydropower is ranked 6th with around 1.3 deaths/GWy and althouth is one of the higher rating among renewables,
it is very low compared to conventional sources.
As a result I think that the focus now should be on small scale hydro
in order to minimize some of the disadvantages and because it is more practical (even though more costly regarding to output).

Best regards,
Angelos Hadjiantoni
MSc Renewable Energy

Source: Sunstainable Energy- without the hot air, JC McKay ,2009

Kelvin Osaro's picture

In regards to the environment, hydropower is essentially safe as compared to nuclear and fossil fuel systems due to fact that there is no thermal degradation of water, no waste and no location involving air emission [3].  However there are several factors that are hazardous to public safety in the hydropower projects these are given below:

Construction of Dams:
The environmental impacts caused by the construction of dam can be through land loss due to the filling up of reservoirs leading to flooding which is the main impact on the local population, especially when agricultural land or house property is affected. This can lead to resettlement and compensation schemes, which is a major issue in the hydropower context. More so, businesses or industries are affected by any alteration of water bodies, landscape and habitats that occurs in hydropower generation schemes either through negative or positive effects[1].

Health Impacts:

In the large hydropower scheme, health issues are of great importance in tropical regions such as South America, Africa and the Caribbean, it has been reported that the existence of reservoirs at hydropower plants have triggered diseases such as malaria, bilharzias (schistosomiasis), and other mosquito-borne infections. More so, biological toxins such as methyl-mercury or algae can be observed in most large reservoirs which are also a further problem to health. Finally, resettlement and loss of habitat and livelihood leads to mental health issues when resettling people thereby leading to individual depression to violence and social breakdown[1].

Sedimentation Impacts:

This is a major issue for reservoirs in that, natural transported sediments alter the lifetime of most hydropower schemes due to the head ponds or reservoirs being filled up with inflowing sediment that causes flooding or reduction in power generation. Also causes existence of fishes impossible or creates habitat too rough for most river ecosystems and effects of low flows and hydro-peaking downstream[1].

Weather Factors:

Weather conditions such as snow, rain, fog and ice can make or cause visible signs of hazardous areas during daytime more dangerous during the night when the visibility of these hazardous areas cannot be seen due to bad weather conditions. More so, wind gust is also an issue in that, the higher the wind the harder for boaters to control the boats thereby, making it difficult to react to warning signs when they are forced into hazardous locations [2].  





Soseleye F. Ideriah's picture

Yes, hydropower utilises an abundant and renewable source in generating electricity but like all major forms of energy in use, it has its shortcomings. When these dams fail, they fail with devastating effects; the Banqiao reservoir dam despite being designed to withstand large floods, failed due to flooding, and eventually claimed an estimated 171,000 lives, destroying the homes of 11 million people in the process [1]. Beyond the dangers of hydropower already identified in earlier posts on this topic, this energy generation option also creates certain environmental challenges. Hydropower dams are very large structures, requiring a vast land area and plenty of water. Building a new dam often leads to relocation of established settlements. Dangers posed to marine life are a major concern as dams may cause obstruction to fish migration and affect their populations [2]. Hydroelectric power plants have been known to also change the water temperature and river flow, causing harm to native plants and animals. Safety is closely linked with environmental issues and in my opinion, negative effects on animal life are additional safety concerns.



Kelvin Osaro's picture

All projects require different types of safety devices, warning systems or other safety measures in order to ensure the safety of the public prone to these hazardous environments. However, the higher the public exposure to these hazardous environments leads to an increase in the amount of safety needed for their protection [1]. These safety devices and measures can be categorised in five (5) such as:

Educating and Informing the Public:

In general, it is important to inform the public of any hazards that can exist close to hydropower projects or any project in order to ensure safety awareness of possible risks. This public awareness can be done through company literature, recreational brochures, television or radio announcements, video tapes, advertisements and newspaper articles [1]. More so, showing warning signs were high risk is to be avoided at any project.

Visual and Audible Warnings of Hazardous Areas:

Hazardous areas require warning devices such as: danger and warning signs, audible warning devices, power communication lines, canoe portage signs, beacons and strobe lights, buoys, verbal warnings, and lights and illumination. These devices are required where essential to warn the public of hazardous areas like powerhouse intake areas, spillways, tailraces, and other hazardous areas and conditions [1].

Procedures for Safer Project Operations:

In most cases, altering procedures for safer project operation can improve safety conditions at a project. For example, modifying gate opening procedures may reduce or eliminate sudden surges in flows or may be used to direct flows to less hazardous areas. More so, imposing or changing ramping rates for generating units can prevent sudden increases in tailwater levels. Nevertheless, it is vital for all project operators to encourage the review of operating procedures as they affect public safety and to ensure that any necessary developments are consistent with good public safety practices and the primary purposes of the project [1].

Escape Devices:

Escape devices serve as a means of escape for people who are otherwise or unable to get out of hazardous waters. These devices are such as safety ropes, life preservers, escape ladders, suspended cables and escape nets [1].

Physical Restraining Devices:

In general, in order to ensure the safety of the public against hazardous areas, physical restraining devices should be in place. These are boat restraining barriers, fences, guardrails, natural barriers, trashracks, debris deflector booms, and other similar devices [1].




FELIXMAIYO's picture

I would like to agree with most of the people that hydropower is one of the cleanest and the safest form of energy. Some of the key factors that have to be taken in consideration to meet the above standards are: proper planning, proper designing and proper maintenance. But project people work towards all those they impact on various sectors of the environment and also the population
One of the disadvantages is that it interferes with the aquatic ecosystem because dams have to be constructed; this leads to large scale destruction of the aquatic life. One the turbines have installed there is a chance of fish and other water animals entering the penstock and ultimately the power generation where they will be killed.
There is the disruption of the surrounding areas :plants and animal life tend to do well along the fresh flowing rivers and construction of the dam will force them to move to a different place, also the trees along the rivers will have to be cut down to give way for the dam.
Construction of a dam will always occupy a large area and for this area to be found human displacement has to take place and this leads to loss of property. This is to avoid a similar accident as the 1975 Banqiao Dam failure in China

YAKUBU ABUBAKAR 51126107's picture

There are a number of safety and environmental concern of
hydroelectric power generation, In most  places all over the world the integrity of the
dam is not totally unquestionable due to the large volume of water it collect
every year which consistently weaken the structural strength of the dam.

There are always a risk dam breaks and flooding that kills
and displaced millions of people around the dam and destroyed property with
uncountable environmental consequences to the flora and fauna every year around
the globe.

During the construction of the Dams it involves a lot of
heavy engineering machinery with a lot of Greenhouse emission which pollutes
the environments. During flooding the water displaced also produces CO2
emission which is detrimental and unsafe to the environment.


Yakubu Abubakar.

Ref. › ... › Renewable Energy  Hydroelectricity

chukwuemeka uzukwu's picture

electricity is another term for power generation by harnessing the power of
moving water.

Overall hydro power
is safer than fossil fuel systems and nuclear as there are no site air
emissions, no waste and no thermal degradation of water.
The creation of hydro power usually requires the diversion of the water at an
existing waterfall or the creation of a reservoir.

While hydro electricity seems
relatively clean and safe in comparison to burning fossil fuels
(coal or
oil or natural gas), nearly all large hydro electric installations in the world
have had significant impacts on nearby environmental habitats once they are
brought online.
The diversion of a waterfall may not cause problems as the water is
eventually released to the same water course. The hydro power reservoir with
its associated dams is another case.
 This is because they significantly impede the
flow of water in rivers and lakes at the point where the generating dam is
installed In turn, this causes significant increases in water levels in
corresponding upstream water systems while at the same time creating much lower
water levels downstream. A typical example is the flood being experienced in
Nigeria at the moment.

Omololu Oyebola's picture

Hydropower’s renewable nature, little or no greenhouse gases and other noxious emissions makes it advantageous over other forms of energy generation. At the same time, hyropower has negative effect on the environment, and some of the safety issues are earthquake vulnerability, wildlife and fishes get affected, tail risk and dam failure.

Hydropower stations situated close to settlement areas can expose people to flooding, the building of large dams can cause serious geological damage. For example, the building of the Hoover Dam in the USA triggered a number of earth quakes and has depressed the earth’s surface at its location. About 1,500,000 have been relocated away from the Three Gorges Dam[1].

Dam development can have adverse effect  on the quality of water in that region in several different ways, destroying the natural vegetation can result in soil erosions and land slide, which can cause a buildup that of sediments that can clog up the streams.

In summary, safety problems associated with hydropower are, area exposed to flood, ecosystem will be altered, and displacement of human settlement.


Deinyefa S. Ebikeme's picture

People always come first in the "cause and effect scale" of any projects and when they are affected from such projects negativity especially in the event of any accidents to a great magnitude they tend to castigate and tag it as unsafe sometimes ignoring its initial benefits (ie 1975 China Banqiao Reservoir Dam failure with 26,000 dead from direct flooding, 145,000 dead from subsequent famine and epidemics, 11 million homeless. Caused loss of generation, dam failed by overtopping. Russia 2009 Sayano-Shushenskaya hydro accident, 6 GW power generation loss, 75 fatalities, due to turbine failure etc). It's true that hydroelectric power generation has affected humans over times going by the records of hydroelectric power failures were several lives had been lost but its benefits cannot be neglected (renewable source, zero green house gas emission compared to fossil fuel plant, environmentally friendly to an extend etc). Majority of these accidents experienced from hydropower had to do with human negligence to boardly and properly tactle the area of design stage flaws, apply viable technology to withstand the energy in turbulent flowing water and maintenance culture inactiveness for these plants. This falls have now been taken into full considerations which includes enivronment impacts such as natural disasters with dam now constructed to "safely" withstand earthquakes up to 8 on the Richter scale and also the ecosystem of aquatic mammals in such regions and are been checked by various legislative bodies.

Deinyefa Stephen Ebikeme IBIYF

Ekaterina Pavlichenko's picture

I am surprised at any contribution on this topic that can be seen as positive and I’d suggest that to take a look at Hydro Electric Power we have to look at this in a global context, as to the greater extent ingenious peoples that live in the location of a Hydro Electric Dam, live in a nightmare scenario.

There are considerable health impacts for the people living in the location of a hydroelectric dam such as the spread of malaria, hepatitis, schistosomiasis and river blindness.

More often than not frequent engineering and safety problems as these projects are mostly funded by the world bank; dams thrown up by companies keen to maximize their profits on what is often seen as ‘money for jam’, with little regard to quality and safety.

Dams with shoddy construction are easy targets for saboteurs and given that these projects are often undertaken in less politically stable counties they become pawns in the game of political control.

Also, the construction of a hydroelectric dam often means the destruction of unique local natural resources such as historical archeological sites. Unfortunately, this never deters the financial backers or construction companies from moving ahead with these projects, which also usually involves the relocation of the indigenous peoples and destruction of local wildlife.

The consequences of building a Hydro Electric Power Station are far more disastrous than any potential benefit.


Dam is constructed for multiple purposes which
mean generate electricity, preventing flooding, controlling water supply. Also,
hydropower itself has a positive perspective as environmental friendly
renewable energy.  

However, dam construction influence on
ecosystem nearby area. Once water is not flowing consistently, water quality in
the upstream could be worse easily. e.g. increased algae and severe eutrophication
and increased humidity in dam area can cause respiratory diseases. Especially
in case of Hartbeespoort Dam, its water quality was exacerbated because of
polluted water supply to the river [1] On the other hand, water ecosystem in
downstream will be destroyed and cause a damage in fishing industry.

Additionally, unplanned dam operating could
be a safety issue. Hwang gang dam in North Korea had opened its gate suddenly
at 2009 and 6 people in the downstream area are dead because unawareness of
operation. Accident is happened mainly because military tension between South
and North Korea. [2] Anyway this shows hazard from unplanned operation can be

To sum up, Hazard from hydropower could be change
in climate and ecosystem in nearby area, unplanned dam operation puts people in
downstream in danger.









Ekaterina Pavlichenko's picture

Chang Hwan is right, Hartbeespoort Dam is a classic example of regime failure, with two million liters of sewage (some of it raw) flowing daily down the Jukskei River into the dam, all done ‘legally’, but this is not the worst of it; the Pelindaba nuclear plant is licensed to routinely dump vast quantities of nuclear waste into the Crocodile River, just above the dam; it’s been reported that radioactive liquid waste has been released into the Crocodile River at the rate of over half a million litres per day!

The Hartbeespoort Dam is a major source of local drinking water, is massively polluted and yet the authorities in control deny any concern.


Where will this end?


Ber_Mar's picture

Altough most of the dear collegues seem to adress the safety or not of the operation of a water dam, i would like to adress a diferent matter which is related to the construction phase of hydroelectrical power plants.

 Due to their specific construction method and the need to divert water streams or not to produce a barrier for the forthcoming artificial lake to be sustained, these type of construction can be in fact "tricky". In Portugal a Hydro Power plan is beeing set into motion with the construction of 15 to 20 diferent hydropower plants. 

 Even considering the risk managment and taking into care all the pro active preventive mathers, the earthworks stability the level of uncertainity related to soil mechanics is so big, that accidents end up happening. From the beginning year have died 3 people just in one accident and then other 2 in another. 


Elvis.E.Osung's picture

Hydropower can be considered fairly green because of the near absence of carbon emissions. This does not entirely imply that dams are safe. Identifying the hazards and assessing the risks involved in Hydropower includes considering the environmental impact of both the construction and operation phase, besides affecting aquatic habitat in the construction phase, in the operation phase dams are subject to the risk of collapse, some times to prevent failure of dams as a result of increased water levels, the gates are opened which causes flooding among people living downstream.

 A recent event of increased water levels in a dam in Cameroun led to flooding in many states in Nigeria killing several people and displacing thousands.

Kii Cajetan Barisi's picture

potential issues in hydropeaking
Where reservoir hydro schemes are operated primarily to provide peak load services, there are
particular environmental risks that should be considered in any environmental impact
assessment. With a sound understanding of the potential environmental issues, there are
strategies that can be employed at the siting and design stage to minimise or mitigate these
With any hydro scheme, the downstream river environment has an altered hydrograph due
to the curtailing of major floods and a flow range restricted to the turbine discharge capacity.
For a peaking station, a typical hydrograph shows twice-daily fluctuations from off to full
capacity discharges often with weekend shutdowns. A peaking station may show consistent
daily to weekly patterns of discharge throughout the year rather than the strong seasonal
pattern that might be shown for base load providers, and depending on the scale of the scheme
inter-annual variability may be low.
Downstream effects on water quality depend on the storage configuration and offtake
depth. If the storage is deep and stratifies and the offtake is low, the downstream
environment may experience frequent temperature and dissolved oxygen fluctuations
particularly during the summer period, with the power station injecting cold water from deep
in the reservoir into the warmer waters of the receiving environment. In situations where
there are downstream pollution sources draining into the river system, peaking power station
discharges can cause pulses of polluted water downstream rather than a general dilution effect
when operating to meet baseload demand.
Downstream effects on the fluvial geomorphology and dominant geomorphic processes
differ if a power station is operating to meet base versus peak demand. Major issues with any
hydro operations are with the reduced sediment supply to the downstream environment and
the erosive capabilities of continuous larger than natural baseflows for baseload operations.
With peaking operations, the significant flow discharge patterns affecting the channel form
are the rate and frequency of water level rise, the time the station is at its maximum discharge
level, and the rate and frequency of water level drop. A rapid increase in water level has
considerable bank scouring capabilities. The amount of time the power station discharges at
its full capacity influences the degree of saturation of the river banks, which in turn influences
the degree of seepage-induced erosion that may occur when the power station turns off.
Frequent and rapid drawdowns in water level result in considerable pore water pressures as
the water drains out of the banks, so with peaking operations the frequency of seepageinduced erosion events increases, however the severity of any one event may be less than
otherwise if the power station has not been on long because the banks will not be as saturated.
Downstream effects on riparian vegetation with any hydro operations can be a loss of
species cover and diversity in the riparian zone due to waterlogging and inundation, lack of
regeneration and recruitment, and habitat alteration due to bank erosion. Inundation is the
submergence of vegetation that prevents gas exchange, and prevents plants carrying out
photosynthesis and respiration through their leaves. Waterlogging is the submergence of the
root zone, which causes depletion of oxygen in the soil and prevents respiration by plant
roots. Light limitation is also a stress because plants require adequate daylight hours without inundation or waterlogging to acquire carbon through photosynthesis. With peaking
operations there are reduced risks of impact due to waterlogging and inundation, as the
riparian zone is drained and exposed to sunlight on a daily basis. However there is still the
case of limited regeneration and recruitment, because seedlings can not establish on the banks
where water levels rise rapidly several times per day and wash them away. Banks close to the
power station may eventually end up with a high percentage cover of mineral substrates, and
riparian tall woody shrub species may be replaced with ephemerals such as grasses,
gramonoids (grass-like plants) and tolerant semiaquatic herb which may provide some
structural stability to river banks.
Downstream effects on macroinvertebrates (e.g. aquatic insects and micro-crustaceans) for
any hydro operations are often a reduction in species diversity and abundance, as well as loss
of edge and snag habitat. The significant drivers of these impacts are that the water levels
with the power station off are often lower than mean summer baseflows resulting in less
habitat availability for colonisation, and water levels with the power station on are often
higher than mean winter baseflows resulting in greater depths and current velocities than
optimal for some species. With peaking operations, water levels change across this range
several times per day, and frequent water level as well as temperature changes would cause
high stresses on the instream biota. For example, high shear stresses, that is the force applied
to the river bed from rapidly rising water levels, is associated with faunal displacement and
possibly bed movement under rapidly varying flows.
Hydropower schemes can affect migratory aquatic species due to the physical barrier to
upstream migration presented by the dam itself. Baseload discharge patterns can reduce fish
populations in the downstream environment due to reduced macroinvertebrate food supplies,
loss of snag habitat, and impacts on spawning and migration cues due to changes in the
seasonality of flows (and in cases temperature). Where there are natural downstream
obstacles to fish migration such as river gorges, baseload discharge patterns may cause fish
migration difficulties due to sustained high flow releases, whereas peaking discharge patterns
may provide more frequent opportunities for migration through these gorges.
Social issues can also arise due to peaking operations, for example human safety issues
with rapidly changing water levels, risks of stock strandings, and issues with pump set-ups for

Kii Cajetan Barisi's picture

Hydropower and its Impacts
Hydropower raises specific environmental issues,
related to the transformation of land use and of
river flow patterns. These issues vary substantially
from one geographic context to another. Every
hydropower plant has unique characteristics: It
may be located in desert or semi-desertic ecosystems, in high mountain areas, in tropical forests,
in agricultural valleys or urban areas. It may be
in a populated or unpopulated area, it may have
a large or small reservoir, or none at all. Examples
of major concerns include involuntary population
displacement, the flooding of natural habitats, or
the threat of increased water-borne diseases in
tropical countries, among others.
The case of involuntary resettlement is symptomatic of the challenges confronting hydropower
development, and the analysis of its impacts.
Resettlement is a very significant impact for
certain specific projects, and must be managed
competently and fairly. Otherwise, human
tragedies may result, where people are dispossessed of their livelihoods, communities are
uprooted and vulnerable populations dispersed.
There are cases of such occurrences associated
with various major public infrastructure projects
- highways, urban development, power stations -
including major dams. Nevertheless, many
governments are convinced that with good
resettlement programs these projects generate
collective benefits, in terms of power, irrigation
or other uses, which largely exceed the adverse
It is essential that the significant social impacts
of involuntary resettlement must be avoided
whenever possible, or properly dealt with when
unavoidable. The challenge is to ensure that
hydropower projects foster regional social and
economic development by providing clear-cut
benefits to local people, whether displaced or

human population over the last 3 generations.
In 1990, 28 countries experienced water stress
or scarcity. By 2025, the figure will rise to 50 countries and 3 billion people will be adversely affected, the majority in least developed countries.
There is a need to reverse the trend whereby
demand is outrunning supply of fresh water,
while its quality is declining due to human abuse.
Worldwide competition for water is increasing,
Faced with such daunting prospects, national
and international organizations are developing
frameworks for integrated water management.
These approaches stress the need for basin-wide,
participatory management involving water users,
planners and policy-makers. Hydropower projects
and their dams are inevitably an important issue
in such debates. 

Kii Cajetan Barisi's picture

Hydropower, a Source of
Environmental Debate

Hydropower is one of the many demands exerted
on fresh water. Much of the environmental controversy about hydropower may be related to this
fact, as it may be perceived as an extra "burden"
on an already severely degraded resource. Unlike
hydropower, the consumption of fossil fuels for
thermal power generation actually "depletes"
resources by burning the fuel, but the fuels
used - coal, oil, gas - are not perceived as lifesustaining resources.
Hydropower, which was long seen as a "clean" and
"renewable" way of generating electricity and regulating floods, is now often perceived, particularly
in developed countries, as a "threat" to ecosystems
and a net loss for the environment and society
alike. The most vocal opponents to hydropower
today are environmental interest groups
, some of
which recommend to stop building dams, and to
dismantle some of the existing ones. Interestingly,
the controversy often focuses on dams rather thanWhat are the environmental impacts of available
electricity production alternatives?

Elle Allswell David's picture

Hydropower or Water power is power derived from the energy
of falling water, which is harnessed for useful purposes. (

Hydropower is used for the generation of electricity in most
Countries. In Nigeria there is the oldest dam Kainji dam across the River Niger
which generates about 960 megawatts of electricity for the country.

Their fuel supply been water is clean which means they will
not contribute to the emission of greenhouse gases and it also helps at times
in controlling flood.

Hydropower dams also have their disadvantages and risks.  It can affect water quality, it can also
result in flooding when it is opened if the water in the reservoir is too large
for it to contain. The case of Nigeria presently is a good example; presently
more than one fifth of Nigerian states has been flooded as a result of water
from the reservoir of a Hydropower dam. This has cost the Nigerian government
Billions of Naira to take care of its displaced citizens. This means that the ecosystem
has been destroyed, so while we talk of the safety of a Hydropower the Negative
aspect should also be taken care of.

Ryan Grekowicz's picture

After scrolling down through my fellow classmate's posts, there was one environmental impact that wasn't mentioned.  I grew up in the Northwestern part of the United States where there are many dams that were constructed to provide electricity to the region.  The once mighty Columbia River has now been reduced to a several hundred mile long reservoir as a result of the numerous number of dams, which is sad, but has no measurable impact.  The one impact it did have, which was a very big deal in that part of the United States, was that the dams nearly decimated the once very strong salmon runs.  (FYI- salmon are a type of fish that live their first year in a river, then migrate to the ocean, where they live for a couple years before returning to the same river they were born in, to spawn and then die)  The salmon play a very important cultural and economic role in the region, and it was a huge blow to both when their populations started decreasing.

The electric companies attempted to mitigate the issue by installing "fish ladders" which allowed the salmon to swim around the dam, and they also started allowing additional water over the spill way when the baby salmon were migrating downriver so that they weren't chewed up by the turbines.  These measures have allowed it so the salmon haven't become extinct, but their populations are so low that fishing isn't allowed in many regions.

Besides the salmon issue, I know of no other problems with hydroelectricity production; therefore, I would say unless there is a similar environmental impact, then hydroelectricity is a terrific option for renewable energy. 

Siwei Kang's picture

It is obvious that hydropower is one of the safest and most reliable energy. Except flawed design and poor consturct, it could be operated safely, at least its lower FAR and AFR compared with other industry, like oil and gas. However, should we really encourage to build more hydropowers? Personally speaking, the risk of hydropower is the biggest problem.

One of the risks need to be considered is the regional ecology could be affected after hydropower commission. Take China for example, during the past five decades, more than 230 large and medium-sized hydropower stations have been built. The Three Gorges Hydropower Station, total installed capacity of 18.2 million kilowatts, is now the world's largest hydropower station. After commission, it provides large amount of electricity generation and largely eases energy shortage. However, it also significantly deteriorates the ecological environment along the Yangzte River, even the climate in China. From 2008, the Three Gorges Hydropower as-built two years later, the areas along the Yangzte River experienced frequent abnormal climates. Due to damming, the Dongting and Boyang lakes, which is located in the dwonstream of Yangzte Rizer, has already dried up. It is said that the WenChuan earthquake happened in 2008 was induced by the Three Gorges hydropower. 

Another risk is the terror attack or war. If the dam is exploded by terroists, the downstream could be flooded and all people in that region will die. The effect is devastated. On the other hand, if there is a war between countries, the dam could be the first attack target. Although the destrust of dam due to war or terror attack has not happened, it is a big risk.

Nowadays, with the hydropower construction is increased, it is better to know its potential risk firstly.

Ekaterina Pavlichenko's picture

With the majority of the world’s rivers dammed at some point, we are coming to the point where room for additional hydro plant is getting more and more limited. Wouldn’t it be really nice to allow the environment some space; this desire to plant a major earthwork across every available damming location to supposedly meet the power needs of this or that industry really isn’t worth it.

Not only the major environmental and social impact that surrounds the building of the dam in the first place, but once built we’re left with an environmental mess that costs millions to try to maintain; all for what is in most cases, at the end of the day a source of ‘top-up’ power for periods of peak demand and usually something that could easily have been sourced by either upgrading an existing turbine or expanding existing power stations close to the industries that required the power in the first place.

With the tight restrictions on the operation of fosil fuelled power stations (scrubbers in cooling towers, etc.) and the even tighter constraints that will be applied year after year, looking to the future the case for supposedly 'green' hydro falls away drastically.    

Ekaterina Pavlichenko's picture

Anyone who supports the building of more dams should try to read the book, Deep Water: The Epic Struggle over Dams, Displaced People, and the Environment, by Jacques Leslie. In his book Leslie points out that as far as resources go, Water is going to be the Oil of the 21st Century.

We need to carefully think out our water strategy for the future; currently most British water companies cannot go a week without rain before crying ‘drought’, perhaps being facetious here but the point is that there is little regard for the long term future for the water supply in most countries and the sooner we look globally at this issue and come up with sustainable programs the better the future prospects for the human race; building more dams is not the solution!

I’d like to include some points from Leslie’s book:  

•Although the perception is dams provide clean energy, dams in the tropics can produce dangerous greenhouse gases in the form of methane (a particularly bad greenhouse gas) as plants in the base of a reservoir rot after being flooded

•All dams are a temporary solution because they eventually fill up with silt which means they are not a sustainable solution

•The amount of water captured in dams has shifted the weight of the earth toward the equator which in turn effects the earth's gravitational field

•Throughout the world, the large dams symbolize the power and authority of central governments

•One of the biggest problems with the world's biggest dams is the enormous consequences borne by the people who are displaced by the reservoir created and the people downstream who no longer have the dynamic river ecosystem that created their environment

•As with many large construction efforts, the greatest effect is to enrich those in the government that built them and to encourage graft and corruption

•The United States has come to realize that dams are not an unmitigated blessing and now are dismantling dams that don't provide much benefit.

•Yet, the World Bank is still financing dams like the Three Gorge Dam in China despite the huge cost to the people and the environment.

t01sik12's picture

Developing the hydropower potentially offers many challenges, and pressures from some environmental action groups over its impact has tended to increase over time. Hydropower throughout the world provides 17% of our electricity from an installed capacity of some 730 GW, making hydropower by far the most important renewable energy for electrical power production.

Hydropower stations situated nearby residential or settlement areas can expose people to flooding, the building of dams around the settlement areas can cause serious geological damage and also affect water quality.

In order to ensure the safety of the public, physical restraining devices should be implemented.examples:boat restraining barriers, fences, guardrails, natural barriers, trashracks, debris deflector booms, and other similar devices's picture

Hydropower  Hydropower system uses rivers and lakes that have gravitational potential energy of water, to transform into kinetic energy of the turbine. Then, through the turbine rolls, to promote the generator to produce electricity. Generally, we often consider it as renewable energy as it is clean and inexhaustible. However, in my view, this kind of energy is double-edged sword. there are also some disadvantages which will lead to environment pollution and other issues. 

advantages: clean energy and long-term investment benefit;                  

                   renewable energy, almost inexhaustible;                   

                   relieve the flood and drought disasters;                 

                   high water level benefits the shipping; 

disadvantages: block the migration path of fish;                    

                       high water level will destroy the upstream landform, ruin some towns;                  

                      destroy the ecological environment;

                       high water level will change local crustal stress which associates with geological disaster;


Consequently, there are lots of protential risks in this technology. The experts just tell the public how impossible of the risk become disaster. However, when the catastrophe really happen, nobody can image the horrible results.

Bassey Kufre Peter's picture

My colleagues have spoken intensively well on what  hydropower and its mode of generation is all about.

But it will interest us to know that Hydropower accounts for 16 PERCENT of global electricity consumption, and 3,427 terawatt-hours of electricity production in 2010, which continues the rapid rate of increase experienced between 2003 and 2009.

Hydropower is produced in 150 COUNTRIES, with the Asia-Pacific region generating 32 PERCENT of global hydropower in 2010. Statistics also revealed that CHINA is the largest hydroelectricity producer, with 721 terawatt-hours of production in 2010, representing about 17 PERCENT of  domestic electricity use.

The cost of hydroelectricity is relatively low, it makes it a competitive source of renewable electricity. Also giving room to developing countries to generate their power.

Considering the unending list of benefits of hydroelectricity, and also from its mode of generation already talked about by my colleagues and comparing its safety relative to other sources of power generation, I categorically affirmed that Hydroelectricity  eliminates the FLUE GAS EMMISSIONS FROM FOSSIL FUEL COMBUSTION, including POLLUTANTS such as SULFUR DIOXIDE, NITRIC OXIDE, CARBON MONOXIDE, DUST, AND MERCURY IN COAL. Hydroelectricity also avoids the hazards of coal mining and indirect health effect of coal emissions.

Comparing it with NUCLEAR POWER, hydroelectricity generates no NUCLEAR WASTE, has none of the dangers associated with URANIUM MINING, nor NUCLEAR LEAKS, Unlike  uranium, hydroelectricity is also a renewable energy source.

Comparing it with Wind Farm, hydroelectricity power plants have more predictable load factor. If the project has a stage reservoir, power can be generated whenever it is needed. Hydroelectricity plants can be easily regulated to follow variations in power demand.

With the right application of Goal Setting Legislation, the risks in Hydropower are reduced to as low as reasonably. 




Bassey, Kufre Peter
M.Sc-Subsea Engineering-2012/2013
University of Aberdeen.

Sineenat Kruennumjai's picture

Discussion Topic 24 Safety in Hydropower
 Hydropower is the power comes from the extraction of the energy of water cycles, for example the energy from water falls from dams. Hydropower can produce renewal energy by does not require any fuel, and also does not directly emit any greenhouse gas. So, this technology is seen to be an environmental friendly resource. But it is still have some hidden risks, such as the failure of the Banqiao Dam in China. This accident killed more than 171,000 people and made almost a million of people to be rendered homeless. The cause of this accident might be the quality of constructions. The quality of materials for construct dams have to be of very high, because any breakage in dams can create very large scale of damage of plant, human, and animals. Moreover, the location which will be constructed dams; it should be where abundant quantity of water is sufficient high. This is because when the water level is significant changed, such large quantities of water can cause flooding and disturbing natural flora and fauna.
 Posted by
 Sineenat Kruennumjai
 Student ID 51126536


Hydropower energy uses water to produce energy. So it is renewable,clean and with no greenhouse gas emission. In addition, it has alot of advantages and it is inexpensive way of energy generation.But it has some dangers on marine species and disturbs ecosystem. First, fish may be killed in turbines. Second,Installations are like barriers for their migration. Last of all, supersaturation of air may cause problem for their lives. It is patently clear that the most significant risk of hydropower energy is the failure of dams as we have experienced it alot from the time hydropower has started to generate energy. It can pose risks to the people live nearby since the failure of dam causes flood. It comes to be be more hazardous when the land is likely to have seismic activities.

In order to make hydropwer risk issues more tangible, pay heed to an example. Sayano-shushenskaya dam is the world's six-largest hyropower plant which is located in Russia. It has had four accidents in 1979, 1985 1988 and 2009 respectively. In the last accident 75 were confirmed dead.

Oluwasegun Onasanya's picture

In overall, hydropower is safe than fossil fuel systems and nuclear system as there are no site emissions of green house gases, no
waste and no thermal degradation of water.
The creation of hydropower usually requires the diversion of the water at an existing waterfall or the creation of a reservoir.
The diversion of a waterfall may not cause problems as the water is eventually released to the same water course.

The hydropower just like any other energy system, have its own peculiar issues, some of which are enumerated below,
1. The possibility of flooding the surrounding ecosystems.
2. There is likely going to be impediment for spawning fishes and other aquatic creatures.
3. There is the issue of methane losses from decomposing drowned vegetation.
4  The hydrodynamics of the lower reaches of rivers could be changed.

Among others are some of the safety considerations that needs to be critically looked into for the hydopower systems and facilities
to be considered safe.

1. Safety on reservoirs: Reservoir water levels can rise or fall daily in response to the demand for electrical production, resulting
in floating debris and conceal hazards. Diving or boating can be dangerous.

2. Dam Failure: Dam safety is an important aspect of hydro power, since a dam failure could have serious consequences, causing substantial
property damage and a threat to human life.


1. How is hydropower safe.

2. Operational safety.

Liu Yishan's picture

There are about 90,000 dams in China including the world's largest power station in terms of installed capacity (22,500 MW) - The Three Gorges Dam. It has been a controversial topic since the beginning of installation both in China and the world. The dam not only flooded archaeological and cultural sites and dislocated about 1.3 million people, but also is causing significant ecological changes, including an increased risk of landslides.

The dam locates on a seismic fault. According to the current research, 80% of the land in the area is experiencing erosion, depositing about 40 million tons of sediment into the Yangtze annually. Because the flow is slower above the dam, much of this sediment will now settle there instead of flowing downstream, and there will be less sediment downstream.

The absence of silt downstream has three effects:

  • Some hydrologists expect downstream riverbanks to become more vulnerable to flooding.
  • Shanghai, more than 1,600 km away, rests on a massive sedimentary plain which depending on the arriving silt to strength the bed. If the arriving sediment becomes less, the city may have more risks of inundation. 
  • Benthic sediment buildup causes biological damage and reduces aquatic biodiversity.


The erosion causes a number of landslides which may lead to earthquakes. The people and property downstream would be in dangerous. Therefore, the risk management of dam is in demand to monitor the safety of dams.

Panorama of the Three Gorges Dam Panorama of the Three Gorges Dam



Giorgos Hadjieleftheriou's picture

Safety in Hydropower

Every effort to produce energy
has risks, so hydropower. For example producing electricity from hydropower can
harm the environment and the sea life of the area where the equipments are
installed. Having an assignment to do for electricity production with the help
of tides, I am aware of what are the safety precautions that have to be taken
and which are the advantages of the procedure. Hydropower and tidal power are
both renewable energies, they will never run out. Because they are renewable
they don’t pollute. Using water to produce energy is more efficient and almost
70% of the planet is covered from it. Electricity
production can affect negatively sea life and river life (depends on where
equipments are installed). Throw the cables electricity could make fishes to
leave from the area. Another problem could be caused by the turbines. Fishes
might swim towards them and die.

eddy itamah's picture

The process of capturing and turning the energy of flowing water into electricity is called hydroelectric power or hydropower. This process of exploiting the renewable energy inherent in flowing water is not without its safety issues. One of the environmental impacts of hydropower are related to interventions in nature as a result of damming of water, change water flow and the construction of power lines and roads. Nevertheless, this process of electricity generation by hydroelectric power plants can thus affect fish by distorting their complex interaction between the numerous physical and biological factors. Since fish habitants are shaped by physical factors such as water level, water velocity and shelter and access to food, draining would be completely devastating to these aquatic bodies.

The Other safety issues with hydropower is subdivided into various hazardous level relating to risk factor.

Level 1 risk is during scaffolding work: The basic safety risks identified during scaffolding are

- Falling from height which is extremely hadardous

- Collapse and object hitting

- Earth collapsing, mining hazards such as the use of explosives, uncontrollable contact between men and materials such as cranes and excavator

- The presence of inherent engineering hazards such as injurious gases and toxic dust.

Level 2 risk is electric shock and serious impact from equipment and material handling and fire.


Reference sources:  

eddy itamah's picture

It is a known fact that hydropower construction is extremely complicated with a lot of risks involved and also time consuming.  It is therefore important to carryout findings to identify, evaluate as well as monitor the source of risk, so as to strengthen the control of the potential accidents, to avoid and respond to the severe acciddents and to allocate the resources effectively for the construction safety programs during the process of construction of hydroelectric dam. The aim of this risk assessment and evaluation in hydropower is 

- To ascertain and estimate the level of hazard of the accident which may take place at the various works of the hydropower projects, based on the risk factor which may cause accidents.

- To carefully scrutinize and prioritize the most appropriate safety programs with the allocated resources through the specification of the relevant weight of each safety program for the construction safety of the hydropower project.




Ernest Appiah's picture

power is considered to be very safe as compared to fossil fuel systems and
nuclear since they do not result in the release of emissions or waste and also
do not lead to thermal degradation of water.
In building the hydro power dam usually requires the diversion of the water at
an existing waterfall or the creation of a reservoir. The diversion of a
waterfall may not cause problems as the water is eventually released to the
same water course. However, the hydro power dam could posse many problems. It
could serve as an impediment for free movement of fisheries and also result in
the displacement of local people.


are also concerned that the dams could result in methane losses from decomposing
drowned vegetation and ecosystems flooding. Some argues that the dams could
also change the hydrodynamics of the lower reaches of rivers and not to mention
the possibility of flooding as a result of the dam structural failure. Dam
failure could have serious consequences and could cause considerable damages to
human life. The good news is that the risk of a dam failure is extremely small.
Therefore hydro power cannot be said to be completely safe in this respect.



Ecology and BionomicsEnvironmental Issues

Keqin Chen's picture


As the most widely used renewable energy, hydroelectric power generation has risen steadily by an average 3%
per year in the last forty years. In 2011, the world’s 45,000-plus large dams
in over 160 countries produced 3,500 billion kilowatt-hours of hydroelectricity
which accounted for 16% of global electricity generation. [1]

Although this kind of clean resource has
numerous virtues, e.g. Flexibility and suitability, low costs, the safety concerns
still should be focused on.

Dam Failure

The facilities are designed to hold back
large volumes of water, and any tiny failure due to poor construction, natural
disasters or sabotage (such as terrorist attacks) can be catastrophic to
downriver settlements and infrastructures in numerous dam failures in human history.

2. Potential
Ecosystem Impact

Construction of hydropower station is bound
to take advantage of a drop of water level, which will require the construction
of dams to keep and control the artificial drop. The construction of dams will result
in permanent submersion of extensive areas of the banks of upstream and will force
animal migration, destruction of vegetation, disrupting the ecological balance.
At the same time, sediment concentration after a few years will cause water
level continuing to rise. Fish in downstream will permanently be impossible to
migrate to upstream. Lastly, the shortage of flow will do harm to the ecosystem
of downstream.

3. Relocation Impact

The life of local people will be affected seriously
by the relocation owing to the new build hydro station. And numerous important historically
and culturally sites can be flooded and lost. [2]

[1] Hydropower Continues Steady Growth,


[2] Hydroelectricity


Keqin Chen


Msc of Oil and Gas Engineering


Maxwell Otobo's picture

Hydropower, a form of energy and renewable source is considered as being safe to the environment as there are no site air emissions, no waste and no thermal degradation of water, in other words no land, air or water pollution. But how true is this??

There are a number of environmental issues associated with this form of renewable energy. While hydropower generators cannot be linked to greenhouse gas emissions, the operation of the generator, the hydropower dams and reservoirs can have other environmental impacts.

Dams built to create reservoirs do obstruct migration of fishes to their upstream spawning areas. Reservoir & operation of dams can lead to a change in natural water temperature, flow characteristics, chemistry and silt loads, all of which causes significant changes in the ecology (living organisms and the environment) and land form of river upstream and downstream. These may affect plants and animals. Reservoir may also lead to flooding of natural areas and cause the relocation of people.

Carbon dioxide and methane which are greenhouse gases may also form in reservoirs and be emitted to the atmosphere, though the amount of GHG produced from hydropower plant reservoirs is uncertain.

Hydroturbines are known to injure and kill fishes that passes through the turbines to spawning grounds or to the ocean. For example, in the columbia river situated along the Orejon and Washington, fishes (salmon) must upstream to their spawning grounds to reproduce but the dams along the river is a major obstacle for them. Although an approach known as 'Step-up' has been constructed in place around the damn to the spawning area upstream to fix this problem.

While hydropower is an attractive alternative to fossil fuels, the industry/technology must overcome several obstacles related to the building costs, environmental impact and displacement of people.


Angelos Hadjiantoni's picture


First of all I think there is confusion here between advantages/disadvantages of creating hydropower dams
and the safety and reliability issues related to their operation.

Dam failures are one of the major risks associated with hydropower. 
Now according to Ramage, in the US for instance even though there are 80000 dams, only the 2400 of them are actually used for hydropower.
As a result even though dam failures have happened in the past a cost a lot of deaths (35 major dams failures) only 5 or 6 have to do with hydro power.
Since dams are used for many other reasons except from hydropower, someone might wonder is it worth to have dams at all?
I think that the answer to this is quite obvious.

Now another risk which is more hydropower focused are the plant failures.
The most recent plant failure at Sayano-Shushenskaya power station in Russia caused 75 deaths and a lot of pollution.
Now before blaming hydropower reliability it is good to mention that an inspection to the plant the year before the accident,
stated that all the turbines were unfit for operation due to poor maintenance and age.
So once again the blame for the disaster goes to the human factor.

Best Regards,
Angelos Hadjiantoni
MSc Reneable Energy

Source : Ramage,J., Hydroelectricity. In: Boyle, G., ed. 2012 Renewable Energy: Power for a Sustainable Future, 3rd Edition, Oxford University Press. Chapter 5.

The utilization of hydropower may be associated with a series of
environmental problems.
The environmental issues caused
by construction and operation of hydropower station mainly include plant
destruction and water and soil loss, river channel sedimentation by abandoned
soil and debris, impact of dam on fish migration, the impact of river
dehydration or reducing on aquatic animals and plants, the noise produced by
construction and operation, etc. Based on these reasons, the environmental
evaluation is indispensable for hydropower station development which aims at
getting hold of the impacts on environment, how severe they are, whether there
exist measures to deal with them and how to take steps. After the evaluation is
done, the feasibility of hydropower station could be determined eventually.

Tianchi You's picture

Hydropower plant is one of the most efficient renewable energy in the world; however, there are still some potential hazards behind hydropwer. I want to talk about the postive effects and drawbacks of hydropower   

Postive effects:

  • Clean:Water can be reused again and again without pollution
  • Cheap management , efficient effect and mature technology
  • It can produce electricity depends on the demand
  • Not only be used for producing electricity, but also can prevent of flood
  • Providing the resevoir for irrigation
  • Improving the local economy


  • Potential damage to the eco-system: Decreasing the amount of water below the hydropower plant, and affect the eco-system around the river
  • Once somewhere is designed for the dam, people need to be moved away from the facility
  • Huge investment
  • Once drought happened, the efficiency definitely will be influenced,such as it may stop producing electricity when it does not have enough water in the plant
  • The dam is the target of military conflict 
  • If there was a gap on the dam, the flood will destroy farmlands and people's lives at the downstream 



Tianchi You


Oil&gas engineering

Kyeyune Joseph's picture

Hydropower represents one of the clean renewable energy sources. It is harnessed from energy of flowing water that is converted into flow of electrons. Water pressure rotates the turbine that also rotates the generator finally generating electricity. Hydropower has capacity to respond on short notice as demand for power peaks. Normally, huge water reservoirs are created upstream thus flow of water can be controlled.  Creation of dams on rivers to generate hydropower has a number of issues that include the following:

Impediment to marine life and other ecosystems due to reservoir inundation (rise in water volume and flow velocity) is one of the safety issues of hydropower. In many cases, migration between upstream and downstream is limited. This has negatives impacts especially reproduction of certain marine species.
Methane and carbon dioxide emissions from reservoirs due to deeper water and slower flowing rates as well as flora and fauna covered up in huge water reservoir. Effect of these gases in relation to global warming is well known.
Flooding of large reservoirs upstream especially in rainy seasons when river banks over flow, can put safety of those nearby at a risk submerging farmlands as well.
Navigation can be hampered by surge waves due to unsteady water flow as some power generation units undergo load shedding. This can occur in case where water diversion channels and ship-lock approach channels are in the same canal and can put safety of ships sailing across at risk.
Large hydropower dams are associated with huge construction projects that are well known for high fatality rates. In Norway for example, 23 fatalities were registered on the Tokke 1GW project (1956-1974), 3 fatalities on the Ulla FØrre 2GW project [1]. Therefore, safety is also an issue during the implementation phase of hydropower projects. 

The above issues call for environmentally sensitive technical improvements such as creation of passages for migration of marine species from upstream to downstream and vice versa. This and other measures can minimise environmental impacts of hydropower generation.

[1] Urban Kjellen, Managing safety in hydropower projects in emerging markets- experiences in developing from a reactive to a proactive approach. Available at ScienceDirect  (Elsevier).


Kingsley ENEM's picture

Generally hydro-power is safe than fossil fuel systems and nuclear as there are no carbon emissions, no waste and no thermal degradation of water. Safety is a fundamental aspect and basic requirement for all operations. Negative impact on human health and safety is reduced through comprehensive safety work and well-established risk management systems.
However the hydro-power plants do not require any fossil fuel, it does not produce greenhouse gases and don't generate pollution directly, it does have an amount of disadvantageous effects on the environment. The construction activity of the dam itself disrupts the environment to a great scale. The construction of hydro-power typically involves the alteration of the water at an existing waterfall or the construction of a reservoir. When the course of water is altered the surrounding areas may get flooded troubling natural flora and fauna. People living in these areas also get displaced.
Dam safety is an essential aspect of hydro-power, since dam's failure could have serious consequences, causing threat to human life, significant property and environmental damage. The risk of a dam failure is exceedingly small, and current requirements are calculated for water flows that statistically happen every 10,000 years.
The safety of dams operations is regulated by a number of different organizations. Since river operations are a main component of dam safety, licensees are required to document compliance with project flows and reservoir operation plan requirements.

Aleksandr Poljakov's picture

of all, I would like to disagree with people saying that it is one of the
cleanest energy sources. Hydropower development usually requires constructing a
concrete dam, and flooding the surrounding area. Vast amounts of concrete used
during construction of the dam, have quite high embodied energy and carbon
dioxide, which is due to cement used in concrete, which has one of the highest
embodied CO2 off all the materials used in construction. So throughout its life
span, hydro power station has similar total CO2 emissions as gas CHP plant with
integrated catalysts. High embodied energy of concrete (cement processing is a
very energy intensive process) makes hydropower hide its real cost over the
life cycle of the power plant.

Poljakov, MSc Oil and gas Engineering

Aleksandr Poljakov's picture

in terms of safety, hydropower plants are one of the safest energy production
facilities. However, the major influence on the safety is the design of the
structure and the initial design. Structural failure of the dam and/or failure
of mechanical systems are one of the main reasons for catastrophic failure of
the hydropower plant. Therefore, it greatly depends on structural design of the
system, process plant design, and maintenance are very important elements of
the system. Design lifespan of the structure should also be adequate and
include possible floods in the area. For instance, average lifespan a dam is
usually 50-100 years, withstanding 1 in 50 years worst case floods. There are
some extreme cases, however, one of which is Dutch dam, which was designed to
withstand water pressures and level happening one every thousand years.

Poljakov, MSc Oil and gas Engineering

Savitha Haneef's picture

 There is no doubt as hydropower is a cleaner source of renewable energy. In the modern world where global warming is a serious issue, hydropower stands out as a reliable and less pollutant energy.

Operational safety is not mucha challenge in hydropower.While considering the safety of hydropower generation, dam safety is a serious aspect to be discussed as said in the previous post.A dam failure would result in serious consequences causing a threat to human life and properties. The risk of a dam failure is relatively very low but with the changing climate and rainfall recieved this is not the case.Hence careful & safety  design considerations should go in the construction of any dams.The construction and design should respect the existing water course, ecosystem and fish passage.And for maintanence I believe good practises are followed  to ensure the safety like regular monitoring of any structural damage and checking of the chemical & physical quality of water to see if there is any accidental splillage of chemicals etc.

Savitha Haneef

MSC Safety & Reliability Engineering

amir masoud bayat's picture

The location and nature of Hydro power plants beside externel threats such as natural disaster and terrorists, makes it a high safety threat facility. The physical safety of Hydro power plants is planned to safeguard them in natural disaster.

The structure of hydro power plant occupaies big areas og geographical region. There ae several essencial significant components in a Hydro power plants which require focused safety measures.

  • Surge chambers
  • Pressure shaft
  • Surface and underground surface
  • Dam/Barrage
  • Heat race tunnels 

One of the most imortant aspects of Hydro power safety is Dam safety which can cause noticeable property damage and a significant threat to human life. However, the probability of a Dam damage is slim to none.


Hydro power is safer than fossil fuels and nuclear as they don’t have any emissions, harmful waste. Still there are some problems relating hydro power plants. In order to produce hydro power we need to create reservoir. This will alter the ecosystem of the surroundings. There are many such problems caused by the hydro power plant. Ecosystem damage is one of the main disadvantages of hydro power. The reservoirs constructed in the upstream will destroy the biologically rich and productive lowland. It affects the aquatic ecosystem of both upstream and downstream. Since the water in the catchment area is not flowing, the heavier particles settle down. This will reduce the production capacity of the dam and capacity to control the flood.These reservoirs will produce Methane gas. The methane gas is a greenhouse gas that cause global warming. This Methane gas is produced from the decaying of plants and animals in the flooded area of a dam. Failure in the dam construction will lead to the largest man- made disaster in history. Failure can be due to poor construction, by natural cause or sabotage

Patricia Fleitas's picture

Looking at the statistics of severe accidents from 1969 to 2000 reported by Burgherr and Hirschuberg (2008), the Hydropower industry represented the energy sector with the highest fatal accidents with immediate causes. Hydropower got 37% of the total worldwide fatalities related with energy-man in the period studied. Moreover, analysing the frequency-consequence curve (FN) it can be noticed that the frequency of fatality accidents in Hydropower is lower than Coal, LPG and Oil respect to less than 100 fatalities per event, however when the number of fatalities increase over 1000 death then Hydropower is more probable to occur than Coal or Oil energy-man severe accidents.

Figure 1. FN curves of severe accidents with more than 5 fatalities in non-OEC

This statistics give a clear indication about the severe damage that this technology can cause when poor design takes place and take emergency actions over an overflow situation or Dam failure is totally difficult to achieve. The best actions to take is PREVENTION by high designs, monitoring and control, determination of perimeter safety area of the community and release channels of rivers in case of emergency overflow. In the case of environmental concerns such as fish life affection, a good strategy of re-location of fish could reduce the environmental effects. To concluded, I support the hydropower technology because more environmental friendly technology than unconventional oil and gas, but good designs are required.


Burgherr P. and Hirschberg S. (2008). “ A comparative analysis of accidents risks in Fossil, Hydro, and nuclear energy chains”. Paul Scherrer Institut (PSI). Switzerland.

Edwin Lawrance's picture

From the posts above
several views can be seen related to the safety of dams. Is it completely safe?
How safe is a dam to the environment! According to my opinion dams are active
structures that pose a threat to the life and environment just like an active
volcano. If something happens it can wipe out a large area within few seconds.
If a dam ruptures nothing can be done in order to control it, and the only
thing to do is to maintain it in order to prevent something like that from
happening. During the construction of a dam vast area of land gets flooded, it
is not only that due to the large pressure exerted by the tonnes of litres of
water earthquakes take place. But all these quakes are not in a big magnitude,
but small tremors. Even if it is a cheaper way to generate electricity the urge
for creating new dams must be reduced. 

Edwin Lawrance's picture

In my state where I live
there is dam named Mullaperiyar, the dam is about 117+ old and is made with limestone,
burnt brick powder and faced with rubble. This is a gravity structure which holds
about 443,300,000 m3 of water. It is still active and has surpassed its
designed age limit, several repairs and strengthening measures were conducted.
This region is earthquake active and studies shows that if an earthquake of
magnitude 6.5 hits the area the dam will collapse flooding 3 districts and
threatens the life of 3 million people. Since this dam is leased to the nearby
state, proposal for the new dam was rejected.

What is your opinion on
this? Should we wait till the dam collapse? Should we decommission this
structure? What is important life or irrigation?

Another threat for
safety is politics

To know more about this
issue just google “mullaperiyar dam”

charlesggeorge's picture



As I go through the topic which
you mentioned “Mullaperiyar dam
”in your post, I believe that the safety
issue of the people living around that dam is very critical. As it is beyond is
life time period, that dam should be demolish or should do maintenance work. As
i look through the dam issue, there is a very big political issue behind the
dam ownership and the water in the dam between two states in India. As i going through
some data’s, I found that there is lot of earthquake tremors of low
magnitude happened in those surrounding area of the dam. So in my opinion, Safety
of the people first for this reason. 

According to the news
surrounding it shows that, if the dam collapse it will affect 1000 kilometers
in which people living and it will be destroy all the places within seconds.
Political attitude has an important role is this issue of safety.  And i don’t
know why government has no key interest to solve this issue.

 So consider the safety of the dam, there
should be

Complete Investigation

Adequate design needed

Checking the Quality of the Construction of the dam  

Regular Operation as well as supervision

Well adapted Emergency action plan required



Charles George

Msc in Oil and Gas Engineering


ROHIT NAIR's picture

I totally agree with your views about the
issue being the safety of people living around the dam. You have mentioned
about carrying out investigations to determine the safety of Mullaperiyar Dam.
I would like to state that as I had mentioned in my previous post the empowered
committee headed by former chief justice of India carried out an investigation
and they concluded by saying that it is a safe and hydrologically stable dam. But
what I don’t understand is that if there is a potential safety hazard and if
millions of life are at risk then why not take concrete steps like decommissioning
it and building a new dam. Is the value of human life less important than the
energy generated by this 116-year-old gravity dam? Also the factors that
influenced the outcome of this report is questionable.

Rohit C Nair
Subsea Engineering
Student id- 51231896

charlesggeorge's picture



I completely agree with your
point of views, now day’s safety of the common people is in the hands of
political people who making laws as well the safety regulations made by them.
As we know these political people will change the law when after the accident
happens only, there will never bother about the safety issues surrounding it.

One the best example for this
issue is the failure of Banqiao dam in china. It happened n 1975 which killed estimated
death of 171000 people and 11 million of people lost their homes. After this
incident only the Chinese government realized for repair and maintenance of
other dams in the country which estimate more than 80000 reservoirs across the
country. This give a clear idea in which people who have power in the government
has an important role for making safety laws and regulation which they will
implement only after when accident happen.

  I think every government
around the world should demolish dam which is beyond its life period and should
have regular inspections to avoid such disasters in future.



Oil and Gas Engineering


ROHIT NAIR's picture

Charles I also feel the same. Safety and well being of the people should always
be the top priority. I would like to draw your attention towards another
incident- Morvi Dam failure. This happened on August 11,1979 in India which
resulted in a causality of about 15000 life being lost. The dam Machchu-2 was
damaged because of the flooding of the reservoir eventually leading to the
disintegration of the earthen walls of the dam, which caused waves upto a
height of 8-10m flooding the city of Morvi in the Rajkot district of Gujrat, India.
Many people are not aware of this incident so I felt the need for bringing this
into debate.


Rohit C Nair
Subsea Engineering
Student id- 51231896

ROHIT NAIR's picture


I agree to your views about the safety of people in the districts
adjoining the Mullaperiyar Dam and also the concerns about the structural
integrity of the dam. But the thing to note is that this is a more politically
motivated issue rather than a factual one. I agree that it is a 116-year-old
gravity dam and it is located at a location prone to seismic activity. But an
Empowered committee headed by the former Chief Justice of India has concluded
after carrying out investigations that the dam is structurally and hydrologically
safe and after carrying out minor strengthening procedures the level of water
stored in the reservoir can be raised from 136 cm to 142 cm.

Now about my opinion, looking at the potential risk it carries and
the number of peoples life at stake, I think decommissioning the old dam and
constructing a new dam is a better and more practical option as how much more
can that dam take.


Rohit C Nair
Subsea Engineering
Student id- 51231896


Kelvin Arazu's picture

A common fact holds that hydro power is safer than fossil fuel systems and nuclear [1]. Since they are no site of air emissions, no waste and no thermal degradation of water is seen in this technology.

The creation of hydro power usually requires the diversion of the water at an existing waterfall or the creation of a reservoir. The diversion of a waterfall
may not cause problems as the water is eventually released to the same water course. The hydro power reservoir with its associated dams is another case.
These systems can:

Cause an impediment for spawning fish

Flooding of the ecosystems

Result in methane losses from decomposing drowned vegetation

Alter the hydrodynamics of the lower reaches

Improving this technology would require the building of walls along the coast, in addition building of bounds to accommodate the spilled water by volume is a
practicable safety measures and moving settlements away from this site could forestall the effect of this technology.


ROHIT NAIR's picture

I agree to your views about the safety of people in the districts
adjoining the Mullaperiyar Dam and also the concerns about the structural
integrity of the dam. But the thing to note is that this is a more politically
motivated issue rather than a factual one. I agree that it is a 116-year-old
gravity dam and it is located at a location prone to seismic activity. But an
Empowered committee headed by the former Chief Justice of India has concluded
after carrying out investigations that the dam is structurally and hydrologically
safe and after carrying out minor strengthening procedures the level of water
stored in the reservoir can be raised from 136 cm to 142 cm.

Now about my opinion, looking at the potential risk it carries and
the number of peoples life at stake, I think decommissioning the old dam and
constructing a new dam is a better and more practical option as how much more
can that dam take.


Rohit C Nair
Subsea Engineering
Student id- 51231896


SanjayVyas's picture

I agree with Aleksandr that Structure design is a core issue. The structural
failure can be initiated by a number of independent or of sequence of events
such as floods, earthquake, upstream dam failure, design failure, etc.

Dam Safety Risk Management is a useful tool that can be applied for management of
risk arising from risk associated with Dam safety issues. It comprises risk
assessment, risk control and decision-making on all aspects dam safety. Risk
assessment comprises risk analysis (identification and estimation), risk
evaluation (using ALARP Principles), and the formulation of decision

Dam Safety Risk
Management for Hydroelectric Projects
byDavid S Bowles

Vyas-51234203 - MSc in Safety and Reliability

amaka.ikeaka's picture

The Mullaperiyar Dam constructed about 116 years back, has
been a source of rising tension between Kerala and Tamil Nadu in India. The dam,
which was built by British Engineers, has been at the forefront of the
controversy, with Kerala demanding that the dam be demolished while Tamil Nadu
insists that the dam is safe, and demands that the water level is increased. I
believe that this issue should be looked at as a national problem, rather than
a problem between two states. If an earthquake were to occur, taking into
account that this dam was constructed during the time when there were no earth
quake proof technology, it could threaten the lives of 3.5 million people due
to the dam collapse.This structure has surpassed its lifespan by more than
66 years, and experts from IIT Delhi & Roorkee have mentioned that it will not
withstand an earthquake and is under serious threat. I believe that human life
is more valuable than anything in this world, and the Mullayeriyar dam should
be decommissioned, and a new dam should be reconstructed.

ZHANGYANAN's picture

Topic 24: Safety in hydropower

The hydroelectric power station first thing to consider flood prevention work of the flood season, the gate operation, as well as rescue organizations. To ensure the normal work and safety of hydropower station as well as nearby residents, Second, we must pay attention to the environment in the vicinity of hydropower station is compliant hydroelectric dam, hydropower diversion buildings, and hydropower tail water buildings whether there are hidden dangers, the last and most important, labor safety protection, electrical work, work at heights, lifting operations, welding, and mechanical compliance with the safety requirements to be responsible for the workers. To make sure at least the personal safety of the stuff


Zhang Yanan  ID: 51233945 


Oluwatadegbe Adesunloye Oyolola's picture

Hydroelectricity is a low-carbon, renewable energy source. Increasing the proportion of the UK's electricity generated using low-carbon energy sources can reduce the proportion that must be generated by higher-carbon sources. The working life of a large-scale hydroelectric power station can exceed 100 years, so when the average lifetime emissions of a hydroelectric power station are calculated, initial carbon dioxide (CO2) emissions are offset by subsequent decades of zero-carbon electricity generation.

These are the climate change challenges facing hydro:

In generating electricity, hydroelectric power plants do not release carbon dioxide (CO2). The carbon footprint associated with hydropower comes mostly from the
construction and decommissioning processes. Government research has found that a large hydroelectric power station emits the equivalent of between 10 and 30 grams of CO2 for each kilowatt-hour (kWh) of electricity it

Construction, decommissioning and decomposition

This figure takes into account the CO2 released during construction and decommissioning of the power station, and methane emissions from decomposing vegetation in the
area flooded to make the reservoir. Building a dam may require the removal of trees that help absorb carbon from the atmosphere. When land is cleared for construction, greenhouse gases also escape from the soil and future capacity to absorb carbon is lost too.  

The carbon footprint involved in making and transporting the concrete used to construct a large-scale hydroelectric power station is significant. Making cement, an ingredient of concrete, releases large quantities of CO2 into the atmosphere. But the working life of a large-scale hydroelectric power station can exceed 100 years, so when the average lifetime emissions of a hydroelectric power station are calculated, these initial CO2 emissions are offset by the subsequent decades of zero-carbon electricity generation.


Oluwatadegbe A.O

MSc Oil and Gas Engineering

Tilak Suresh Kumar's picture

Adding to the above discussion here is an extract from the engineering gudielines for the evaluation hydropower project presenting an over veiw of the dam safety monitoring program.

The integration of a Potential Failure Mode Analysis with a Surveillance and Monitoring Plan and the Supporting Technical Information document, results in a more efficient and effective dam safety program. The added value to dam safety includes:
• Uncovering data and information that corrects, clarifies, or supplements the understanding of potential failure modes and scenarios;
• Archiving the key technical information supporting the evaluation of the dam;
• Identifying the most significant potential failure modes;
• Identifying risk reduction opportunities;
• Focusing surveillance, instrumentation, monitoring and inspection programs to provide information on the potential failure modes that present the greatest risk to the safety of the dam; and
• Developing operating procedures to assure that there are no weak links that could lead to mis-operation failures.



Mehran Vakil's picture

However I am advocate of renewable source of energy, but when I have reviewed the previous comments, my attitude towards renewable energies seems to be negative. I become aware that due to Chinese dam (Banqiao) failure, about 180,000 people died(the daily BEAST, 2009).
Thus, I commenced searching about hydropower and its drawbacks. I achieved some data about hazard incidents associated with hydropower.
The capacity of intake area is finite. Changes in flow regime of rivers connected to the hydropower reservoir may result of flooding (FERC, 1992). Pursuant to the enormous potential energy storage in reservoir, the failure accident would be devastating Hazards consequences accompanied by flooding are famine, destruction of ecosystem and increasing mortality rate (wiki answer, 2012)
BUT, to be fair, from efficiency perspective, being renewable and also not emission of greenhouse gases, hydropower is one of the most significant safe methods in order to producing energy.

1)ANSWER, W. 2012. How is hydro power safe? [Online]. Available: [Accessed 27/11 2012].
2)BEAST, T. D. 2009. Natural Disasters You Never Heard About [Online]. Available: [Accessed 27/11 2012].
3)FERC. 1992. GUIDELINES FOR PUBLIC SAFETY AT HYDROPOWER PROJECTS [Online]. Available: [Accessed 27/11 2012].


is one of the longest used sources of energy and perhaps the most mastered in
the energy industry. However this proficiency has led to negligence from both
operators and regulators alike.

Consequence such apathy has lead to flooding, loss of lives and properties as
result of failure of dams which have earlier shown signs of structure weakness
as in the case of Nyco dam in Cameroun which currently threaten the existence
of lives and communities along the course of river Niger in west Africa.

such apathy must be dealt with if hydropower is to be harnessed safely. Structural
integrity test must be carried out frequently to enable proactive measures based
on forecasted water levels.

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