” Dams have harmed our wildlife and made rivers less useful for recreation.”

Stephen Ambrose, Historian

The Pros & Cons of Dams

advantages and disadvantages of dams

Dams are a kind of barrier which aims to restrict or stop the natural flow of water. Dams have a variety of purposes, including energy generation, irrigation purposes, the creation of habitats for the local flora and fauna or the construction of reservoirs for leisure activities.

Even though they can provide many benefits, the construction of dams also implies serious problems. In this article, the pros and cons of dams are examined.

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Advantages of Dams

  1. Production of large amounts of hydropower
  2. Relatively green energy source
  3. Reservoirs for leisure activities
  4. Additional recreation areas
  5. Irrigation of fields
  6. Assurance of water supply for locals
  7. Water flows can be controlled to a certain extent
  8. Protective measure against floods
  9. Local job creation
  10. Waterways can be used for transportation purposes
  11. May be crucial for the energy transition process
  12. Attraction of tourists
  13. Dams may be able to clean up the water
  14. Increase in food production capacities

Production of large amounts of hydropower

One important advantage of dams is that they enable us to produce large amounts of energy. Hydropower is one of the most promising alternative energy sources and hydropower plants can produce more energy than a nuclear power plant.

Since our world population is growing at an alarming rate and we will need an increasing supply of energy in the future, hydropower may be a great measure to be able to meet this increasing energy demand.

Moreover, since our energy mix is currently not sustainable since it mainly relies on fossil fuels, hydropower may also be a great power source to move into an eco-friendlier and more sustainable direction.

Relatively green energy source

Compared to other conventional energy sources like coal, oil or gas, which imply the emission of large amounts of harmful gases into our atmosphere, hydropower can also be considered to be relatively green.

By using dams for energy production, the air is not polluted and also greenhouse gas emissions will be lower compared to the energy production with fossil fuels.

Thus, by using hydropower instead of fossil fuel power plants, we can vastly improve our overall air quality. Apart from that, there are many other advantages and disadvantages of hydropower.

Reservoirs for leisure activities

Apart from the energy production aspect, dams also provide us with reservoirs which may be suitable for plenty of joyful leisure activities.

For instance, if you live nearby one of those reservoirs, you can go fishing or swimming with your family. You can also rent a boat.

All of those activities can be fun and living near one of those reservoirs may therefore significantly improve your quality of life since you do not have to drive long hours for those kinds of fun leisure activities.

Additional recreation areas

The reservoirs that are created through the construction of dams can also be used for recreational purposes. For instance, many people in our nowadays society suffer from high stress levels since they have a quite demanding job and have to work long hours while also having to take care of their kids.

Thus, during the week, there will be not much time for relaxing and it may therefore be especially important for those people to leave the city on weekends and to enjoy their time at those recreational reservoirs in order to relax and get back some mental power in order to stay healthy in the long run.

Therefore, especially for people who live in big cities and have stressful jobs, reservoirs nearby cities may be a great place to spend their weekends and to relax from their demanding daily life.

Irrigation of fields

Dams have been used in the history of mankind for a quite long time for irrigation purposes. This is still the case in many rural areas of our planet.

Farmers have to tilt their fields and ensure their water supply in order to assure the optimal growth of their crops and to maximize their yields.

Especially in the Southern hemisphere of our planet where water will become an even scarcer resource due to global warming in the near future, dams may be quite important in order to ensure the water supply of farmers.

Assurance of water supply for locals

Apart from agricultural purposes, dams can also be quite important to assure the water supply of the local population in order to avoid water scarcity.

Especially in areas where there is not too much rain, the local population often depends on the water supply from reservoirs in order to get enough drinking water and also to get water for washing and showering purposes.

Thus, depending on the region, dams may also be a great tool to effectively supply locals with enough water so that they can carry out all the tasks of their daily life.

Water flows can be controlled to a certain extent

Without dams, people have to rely on natural water flows and do not have control over where the water will actually end up. This can lead to serious problems since in case of droughts, people may be quite helpless since they might not have enough water to survive without reservoirs from dams.

Therefore, dams are also an important tool to control the water flows and to regulate the water supply of whole regions.

Protective measure against floods

Another advantage of dams is that they can protect locals from serious floods. For instance, if there are heavy rainfalls, villages may become flooded in a relatively short period of time and many people might die due to that.

However, through the use of dams, a high fraction of those rainfalls can be stored in reservoirs, which takes away plenty of water and nearby villages will not have to suffer from floods too much anymore.

Therefore, dams can also be a valid tool to protect the local population from all kinds of unpleasant surprises that come along with heavy rainfalls and floods.

Local job creation

The construction of dams can also lead to the creation of many jobs. On the one hand, plenty of work is needed in order to plan and construct a dam. On the other hand, there is plenty of maintenance, supervision and regulation around the proper operation of those hydropower plants that are located inside dams.

Thus, many jobs can be created through the construction of dams, which may be especially beneficial in areas where people suffer from high unemployment rates and urgently search for jobs in order to survive.

Therefore, the construction of dams can also be a way to reduce unemployment and poverty, especially in poor developing countries of our planet where the economic infrastructure is often quite bad and where well-paying jobs are rare.

Waterways can be used for transportation purposes

Since through the construction of dams, the water flows can be changed to a certain extent, dams can also be a great tool to create waterways for transportation purposes. For instance, transportation on waterways has been a quite important tool to carry around all kinds of goods a few decades ago.

Even in our current age, the transportation of goods on waterways is still of importance in some regions of our planet. Therefore, dams can also be quite beneficial in order to assure the supply of goods for the local population.

May be crucial for the energy transition process

Since hydropower can be considered to be a sustainable and relatively green energy source, it will also play a crucial role in the transition process from fossil to alternative renewable energies.

We as humanity have to switch to renewable green energy sources as soon as possible in order to slow down global warming and to mitigate all kinds of pollution issues.

In order to achieve these goals, the energy that can be produced with the help of dams will be a crucial part of the future energy mix.

Attraction of tourists

Dams may also be kind of a tourist magnet. For instance, some dams like the Hoover Dam in the US or the Three Gorges Dam in China are visited by millions of tourists every year.

This not only increases the popularity of a whole region, it also leads to plenty of income for the local economy since tourists will have to sleep in hotels and eat in restaurants.

Thus, dams can also be an important economic factor, which can vastly increase the income of municipalities as well as for many small businesses.

Dams may be able to clean up the water

Our technological progress is astounding and we are now even able to build dams that can clean up the water through different filters. Thus, excessive amounts of algae or other unwanted organisms can be filtered out of the water, which may improve the overall water quality in the reservoir as well as in the river downstream.

In turn, people may be able to enjoy a higher drinking water quality, which may contribute to an increase in the overall health of the local population.

Increase in food production capacities

Due to the control over water flows through the construction of dams, we can also significantly increase the yields of farmers. Since farmers will have access to plenty of water for irrigation purposes, their plants can grow in an ideal manner and yields can be maximized.

Therefore, also the food production capacities in the respective region will increase substantially, which will be especially important in poor regions where the local population is dependent on the yields of farmers in order to survive.

Problems of Dams

  1. Dams can break
  2. People may have to relocate
  3. Construction costs are quite high
  4. Construction takes a long time
  5. Significant maintenance and adjustments required
  6. Experts needed to control water flows
  7. Sedimentation patterns are changed
  8. Problems for the aquatic life
  9. Slowing down water flows may lead to excessive algae
  10. Deforestation
  11. Methane production
  12. Ecological imbalance
  13. Some people may be cut off from water flows
  14. Challenges and conflicts in times of droughts
  15. May become a political tool

Dams can break

From the previous analysis, it has become clear that there are many upsides related to dams and that they can be quite important and useful in certain regions. However, dams also imply some downsides. For instance, nothing is perfect and through construction or maintenance mistakes, dams can eventually break.

If dams break, large amounts of water will flood nearby valley and cities. In turn, many people will likely die from those dam breaks. Even though the chances for dam breaks are rather low in our current age, there had been dam breaks in the past and we should be aware of this con of dams in order to make profound decisions whether dams should be built in a specific area or not.

People may have to relocate

Another problem with the construction of dams is that in some cases, many people have to give up their homes and move to other locations. This displacement of people had been subject to plenty of discussions in the past.

Nobody is keen on living his or her home just for the purposes of the construction of dams and it should be evaluated on an individual basis whether the benefits for society outweigh the negative effects for those people who have to give up their homes and their former lives.

Construction costs are quite high

Also the construction costs for dams are significant. At our current point in time, the construction of dams can cost many billions of USD since it involves the use of large amounts of material. Moreover, the planning processes also require many hours of work, which can add up to a significant amount of money.

Thus, the construction of dams can be quite expensive and it might take a quite long time until the power that is generated with those dams can offset the tremendous construction costs.

Therefore, depending on the region and the energy production potential, the construction of dams may also not make too much sense from an economic perspective.

Construction takes a long time

Since it is quite time-intensive to plan those dams, it will also take a quite long time until the construction of dams is finished. How long it really takes depends on the complexity and the size of the project.

However, from past experiences, it is fair to say that it can take many years or even decades until the construction of big dams is finished. Thus, decision-makers should take this fact into account and realize that dams are not a short-term solution to overcome certain problems.

Dams should rather be considered as a long-term investment and also the decision regarding whether it makes sense to build those dams should be made by taking a long-term perspective rather than evaluating the project on a short-term gain basis.

Significant maintenance and adjustments required

As we have seen before, the construction of dams can be quite demanding and time-intensive. However, also the maintenance and supervision related to dams can be significant. In order to avoid dam breaks or other issues, those dams have to be observed and maintained on a regular basis.

This will also be quite costly and those costs should also be factored in when it comes to the initial decision regarding whether it makes sense to build a dam or not.

Experts needed to control water flows

Dams can be a great tool to adjust and control water flows. However, in order to do a good job in this regard, plenty of experience is needed since it is not easy to assure the optimal amount of water in many different areas at the same time.

Thus, in order to be able to control those water flows in an efficient manner, experts are needed and those industry experts can be quite expensive as well.

These experts may also be quite rare and municipalities may have a hard time finding the right staff to operate those dams, especially in regions where education levels are rather low.

Sedimentation patterns are changed

Another issue related to the construction of dams is that sedimentation patterns in rivers can be changed. If water flows are changed, also the level of sediments that settle at a specific location in the river will be altered.

In turn, this could lead to a change of nutrient levels in the water and many water organisms may have to adjust to those new conditions or might be forced to move if they do not like those conditions at all.

Problems for the aquatic life

In general, dams are often quite problematic for aquatic life. For instance, fishes often have to travel quite long distances upstream in order to mate. However, if there is a dam or a weir which suddenly blocks their way, those fishes may not be able to reach their mating location and the population of those fishes may greatly decrease due to that.

Thus, the construction of dams may imply serious problems for fishes and other kinds of aquatic life.

Slowing down water flows may lead to excessive algae

Through the construction of dams, also the water flows are often slowed down, which in turn contributes to higher contamination with algae.

Excessive levels of algae often lead to lower levels of oxygen in the water, which in turn can hurt many aquatic animals.

Many fishes might even die since they do not get enough oxygen anymore.

Deforestation

In many cases, the construction of large dams also implies significant deforestation. In order to be able to construct those dams, large areas of land have to be used and forests have to be cleared for this purpose.

However, deforestation is known to be quite harmful to our environment since large amounts of carbon dioxide are emitted into the air when forests are cleared.

Methane production

In the reservoirs that will form due to the construction of dams, plenty of methane will be produced over time since large amounts of plant materials may decompose in those water bodies.

Even though the greenhouse gas emissions related to those reservoirs are much lower compared to the use of fossil fuels in energy production, hydropower cannot be regarded to be entirely eco-friendly due to those methane emissions.

Ecological imbalance

All those environmental problems that are associated with dams can also lead to a significant ecological imbalance. For instance, if too many fishes are no longer able to reproduce since they are no longer be able to travel to their mating area, chances are that their prey will explode in population, which may in turn significantly decrease water quality.

In the long run, water bodies may be covered with algae and the whole ecosystem may collapse.

Some people may be cut off from water flows

Even though water flows can be controlled quite well due to the construction of dams, it doesn’t mean that everyone will profit from these altering opportunities.

For instance, while some villages may profit since they will have better access to water, others will suffer since the water flows have been changed and they might no longer have access to their river at all.

Challenges and conflicts in times of droughts

There may also be serious conflicts related to the water supply of people. Since water is crucial for all life on earth, the supply of sufficient amounts of water is crucial for a civilization to sustain itself.

However, due to global warming, water will become a quite scarce resource in the future and people may literally fight over water in the near future.

Thus, especially in times of droughts, there might be plenty of conflicts regarding how water flows should be altered by dams.

May become a political tool

Since water will become so precious in the near future, dams may also become a political tool to control the local population.

If people are dependent on the water supply from reservoirs and dams, chances are that politicians will gain great power over them, which may lead to unpleasant outcomes in the long run if the government has the wrong intentions.

Top 10 Dams Pros & Cons – Summary List

Dams ProsDams Cons
Power productionDam breaks
Hydropower as relatively green energyPeople may get displaced
Altering of water flowsHigh construction costs
Irrigation of fieldsConstruction of dams can take quite long
Transportation waterwaysRegular adjustments needed
Creation of local jobsSedimentation pattern is changed
Tourist attractionProblems for water animals
Reservoir may be used for leisure activitiesDeforestation
Recreation areasEcological imbalance
Increase in food production capacitiesPolitical tool to control people

Conclusion

Dams have been quite important over the history of mankind. The use of dams implies several advantages. However, there are also some issues related to the construction of dams.

Thus, the decision whether the construction of a dam is reasonable or not should be made on an individual basis in order to maximize the benefits of as many people as possible.

Sources

https://en.wikipedia.org/wiki/Dam

https://www.britannica.com/technology/dam-engineering

https://watershed.ucdavis.edu/shed/lund/dams/Dam_History_Page/History.htm

https://foreignpolicy.com/2020/04/22/science-shows-chinese-dams-devastating-mekong-river/

About the author

My name is Andreas and my mission is to educate people of all ages about our environmental problems and how everyone can make a contribution to mitigate these issues.

As I went to university and got my Master’s degree in Economics, I did plenty of research in the field of Development Economics.

After finishing university, I traveled around the world. From this time on, I wanted to make a contribution to ensure a livable future for the next generations in every part of our beautiful planet.

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