What Is a Dam? | What Is a Barrage?| Difference Between Dam and Barrage | Components of a Dam
What Is a Dam? | What Is a Barrage?| Difference Between Dam and Barrage | Components/Parts of a Dam | Types of a Dams | Purposes of a Dam
What Is a Dam?
A dam is a barrier, typically of earth and concrete, built across the top of a valley to hold backwater.
Dams serve an important function in nearly all aspects of our lives. But what is a dam? Dams are simply barriers that are built to retain water, some are used to channel water and power it, while others are used for their aesthetic qualities.
These structures are usually built near rivers with the intention of stopping water from flowing downstream either for storage or to help maintain a constant level.
Dams can also be used to produce electricity and other sources of renewable energy. They are popular in the US and majorly used for power generation.
An example of a dam is the Hoover dam, which is a major tourist destination in the US, and produces electricity for the surrounding area.
The Hoover dam was built, in the 1930s, with the intention of not only producing hydro-electric power but also providing water storage for the farmers and cities around it.
The purpose behind the building of dams is to control water for both humans and nature. Dams are very expensive to build and require a great deal of specialized engineering skills.
There are many kinds of dams and they come in many different shapes and sizes. They are often made of concrete or mud rock.
Some types of dams are designed to hold back water from going into the oceans in order to try to prevent the Earth of getting saltier.
There are a number of different types of dams, including a gravity dam, rock-fill dam, embankment dam, and a concrete dam.
A dam is built to control the flow of a waterway by holding back water, and is typically made of earth, concrete or rock.
The purpose of a dam is to provide protection from floods, generate electricity, or control water flow for irrigation or the production of hydroelectricity.
Depending on the type of dam, it can serve one or more purposes. The Granite Dam in British Columbia is used to create hydropower and at the same time conserve water.
The Hoover Dam in the United States helps to control the Colorado River flow while used for hydropower generation.
Purposes of a Dam
Dam construction can be accomplished in a variety of ways. Dams can be built in natural valleys, or they may be built across the tops of hills to form “hydroelectric” dams.
The purpose of a dam is to control the flow of water in the desired way, such as diverting it through a particular route. A dam also helps prevent flooding downstream from during periods of heavy rain or melting snow in springtime by storing water in reserve.
They can be used to produce hydroelectric power, provide water supplies in arid regions, prevent floods and preserve river downstream, enhance the natural habitat, and provide a variety of recreational and
Dams require location and design, usually with consultation from the local inhabitants, to accomplish the best and safest possible outcome.
Components/Parts of a Dam
The parts of a dam include;
1. Embankment
An embankment is a hillside that is leveled by constructing a wall of rocks or earth that increases the wall’s capacity to hold water, and creates an outward slope towards the site of the dam.
A dam should be built in such a way as to not alter the natural topography of a site, so as to preserve the ecosystem.
2. Dam wall
The outer part of a dam that carries the full load of water behind it. It is the last barrier within a dam to contain water in times of flooding.
The height and thickness of the dam wall is dependent on the amount of water pressure that is expected to be exerted against it.
For example, a dam built in a narrow valley with high vertical sides requires both sides to be further supported by buttresses or natural rock formations above ground level.
3. Reservoir
A reservoir is a collection of water behind a dam. The mass of this water can be used for a variety of purposes.
This can include irrigation, hydroelectric power, fish and wildlife habitats, flood control and drinking water for towns.
After the area is flooded, it may become home to new species of vegetation and animals.
4. Spillway
A spillway is an opening in the wall that allows excess water to flow through the dam rather than over or under it.
Types of dams include earthen, embankment and rock. Earthen dams are constructed from dirt or rocks, with the material used forming the dam’s core.
An embankment dam is built on an even surface generated from a slope made by digging out the loose material and removing debris.
A rock-fill dam is one in which concrete or earth is used to form the dam’s outer layer.
5. A Buttress
A buttress helps hold an embankment dam in place. A buttress is a protrusion of rock that pushes against the dam, and helps to prevent the mass from sliding down towards the reservoir.
The soil in an abutment can be dirt, rock or concrete.
6. Under-armor or foundation
A foundation prevents water from leaking through cracks within a dam’s structure that occur when the load of water on the structure increases or decreases significantly over time.
7. Aqueduct
A hollow steel or concrete pipe that carries water away from a reservoir to an area where it is needed.
8. Gate
A gate is a structure that can be used to block the flow of water through a spillway.
9. Service spillway
A service spillway has an overflow, as opposed to gates, which allows water to flow through the dam in times of high-water levels.
10. Fill
Fill is the material used in construction of embankments and dikes. This material can be earth, rock or sand.
11. Parapet wall
A parapet wall is a thin, steep wall of earth that helps strengthen the embankment dam.
12. Emergency spillway
An emergency spillway is an overflow structure in the main dam that serves as a backup system in case of failure of the main dam structure.
13. Flood control basin
Water can be held back by dams for use during times when there are high-water levels, such as rainfall or snowmelt, for later use during low-water periods.
14. Heel
The heel is at the bottom of a dam where the water flows out of the reservoir.
15. Face
The face is at the top of a dam where water flows into a reservoir.
16. Valley wall
The valley walls are usually made up of hillsides that help anchor an embankment dam, and hold it in place.
17. Crest
The crest is the highest point of a slope, and is where the wall of a dam meets the ground.
18. Base
The base is at the bottom of an embankment where water flows out of an embankment dam into a reservoir below.
19. Power Plant
The power plant is used to generate electricity using falling water. This is the most important element of any dam system.
20. Sluice way
A sluice is an opening in the dam that can be used to control and regulate water flow. The role of the sluiceway is to remove the silt accumulated.
21. Dike
The dike is a long wall of rock used to create a water barrier, typically across a valley to prevent flooding.
22. Buttress stone
A buttress stone is a protrusion of material that helps hold an embankment dam in place.
23. Dam
A dam is a structure built across a natural body of water to provide long-term storage or supply water for hydroelectric power and irrigation.
24. Retaining wall
A retaining wall is the wall of earth, rocks, tree stumps, concrete or other materials on which an embankment dam rests.
It serves to hold the embankment in place while also regulating the flow of water through its spillway.
25. Retaining wall top
The embankment dam’s retaining wall top is the highest point of the structure and serves as the last barrier to the flow of water through the dam.
26. Groined crest
A groined crest is the highest point of a slope, and is where the wall of a dam meets the ground.
27. Base
The base is at the bottom of an embankment where water flows out of an embankment dam into a reservoir below.
28. Embankment Dam
A dam is a long, narrow wall with one end formed with a sharp point and smooth side that can be built without the use of mortar or bulk concrete, such as earth or rocks.
29. Buttress stone
A buttress stone is a protrusion of material that helps hold an embankment dam in place.
The Different types of dams
The different types of dams include:
A. Gravity Dam.
They are designed to be self-supporting and are usually made of concrete, stone or earth. They look like a wall across the top that lets water flow through while still holding it back with a wall on both sides. They do not have any foundation on the ground.
B. Arch Dam.
They are similar to the gravity dam but will curve outwards more in a spherical form. They are appropriate for soft, unstable soils and they tend to be on steeper hillsides.
C. Buttress Dam.
These dams are made with slight inclines and appear as a series of steps that are anchored into the soil below it. They have high stability and can be used for storing water or hydroelectricity generation purposes
D. Gravity-Arch Combination or Masonry Dam.
These dams are made with several bricks and stones made in a V-shape. The V is filled with concrete, while the rest of the space is filled with rocks.
E. Multipurpose Dam (MPD).
These dams are used for flood control, irrigation, hydro power and electrical generation. They are designed to hold large amounts of water and have space for reservoirs or other purposes but are usually smaller than actual reservoirs.
F. Water Shed Dam.
These dams are built for the sole purpose of creating lakes or reservoirs for water storage and recreational purposes.
G. Check Dam.
These dams are built to control erosion along a channel or stream by developing a type of wall that reduces the velocity of the water flow.
They are usually made out of rocks and earth and can be either permanent structures or moveable depending on its location
H. Weeping Dam.
These dams allow the water level to be lowered as it passes through, thus preventing erosion and lowering the risk of erosion.
I. Sloping Dam.
These are dams built with a slope towards the bottom so that water will flow evenly on both sides of it. They can be made out of concrete or stone and have a foundation below them so that they do not shift too much when it is submerged.
J. Diversion Dam.
These dams are used to control the water flow in a different route. This can be to either redirect water to another area or redirect it in case of an emergency where the dam needs to be cleared. They vary in size and shape but are usually smaller than other types of dams.
K. Power-generating Dam.
These dams have a large reservoir that can help produce energy from flowing water that turns turbines blades. They are usually located where there is a river or waterway.
L. Stone Dam.
These dams are built out of large stones and usually have a concrete base that helps support the rest of them. They can be found in areas where they need support along hillsides or valleys in order to prevent soil erosion from landslides or mudflows.
M. Retention Dam.
These dams are built with one wall that is made of concrete and a slope on the other side that directs water down towards the bottom of it. They can be used for flood control and water storage purposes.
N. Off-stream Dam.
These dams are built to hold back water without involving gravity or gravity-arch form. They are built into a channel or stream and help maintain higher ground levels with the ability to control the flow of water in a more efficient manner.
O. Marsh Dam.
These dams have a small slope at the top that is less than 2% and are usually built on rivers or streams to help create shallow areas for wildlife, fish farming and recreational purposes.
What is a Barrage?
A barrage is an artificial dam often joined with other structures in order to control and apply pressure upon the upstream water level.
The barrage dam is a type of dam that is typically constructed over water. It is often used to control the flow or to redirect it. It is a wide structure that spans the waterway.
The construction of this type of dam begins with a foundation that is made across the river.
This foundation can either be made of concrete or steel and it will usually be built with open or closed sluices on the ends of the dam.
The top of the dam will usually also have open sluices on it. The water from one side of the dam is drawn off to the other side through these sluices.
Shutter or gates are used to control the discharge from either the lower or upper reservoir outlets, but are sometimes used as an alternative to dam gates.
These components allow for easy access to the reserve storage section and also provide a secondary spillway, in the event of a dam failure.
The water is then let through the sluices and into the lower watercourse.
The barrage will give much more reliability for load balancing than just depending on one reservoir for storage or hydroelectricity generation.
Difference Between Dam and Barrage |
A dam is a barrier that holds back water from flowing downstream. A barrage is a type of dam, but it’s designed to control the flow of water and/or generate power
Dams are usually built for irrigation, flood control, or hydroelectricity while barrages are often used for navigation
Barrages have gates that can be opened or closed to allow more or less water through them
The word “barrage” comes from the French word “barrier,” which means “to block.”
A dam is a barrier that blocks the flow of water or stops it from flowing where as a barrage is an artificial obstruction, typically in the form of a long wall built across the mouth of a river to control its flow and to provide increased capacity for shipping
Dams can be used for hydroelectric power generation, irrigation, flood control, and navigation. Barrage are often used as fish ladders to help migrating salmon get upstream past dams on their way back to spawn in the springtime
Dam building began with ancient civilizations such as Rome and China but reached its pinnacle during 19th century industrialization when many large projects were undertaken by governments all over the world including England’s Lake District (now known as Windermere) and America’s Hoover Dam (in Nevada).
Dam and Barrage FAQs
What is the difference between a Dam and a Barrage?
Although both are designed to hold back water the differences comes when one reservoir gets filled up. If the water level rises above the crest of the dam there is nowhere for it to go, so it will start to back up behind the barrier.
However, if this happens with a barrage, many of them are linked together by harnesses in order to store overflow on a different part of the river. This makes Barrage more favorable than Dam due to its flexibility.
What type of earth dam is the most popular?
The dam is made of earth and concrete and is generally made in either a gravity or arch form. The slope of the dam will vary with different types of dams depending upon the current depth, flow, velocity and other water parameters.
Can I use a weeping dam?
Yes, if you want reliable storage that is less prone to leaks than a building style dam.
Can you build a dam across a river?
You can build a dam across any waterway that is fairly large. You would want to make sure that you check with local authorities first to ensure that there are no obstacles.
In order to build it, you must plan the structure out very carefully and proceed with caution.
What is the best form of barrage for water storage?
This depends upon several factors including the flow rate, soil type and what purpose it will serve.
If you are going to use it for hydroelectricity generation, it should not have any openings or openings that are more than 3 feet.
These types of barrage designs will give you a better quality than other forms in that they are more consistent with each other.
What are the advantages of using earthen dam?
The main advantage is that it is economical. They also have high resistance against erosion, which makes them safe from erosion and landslides after years of construction.
What is the biggest dam in the world?
Currently, the largest dam in the world is the Three Gorges Dam in China with a height of 181 meters. It was completed in 2012 and serves by generating energy for its neighboring areas along with creating a waterway for ships. The second largest dam is the Xiluodu Dam located in China with a height of 286 meters.
How does barrage work?
A barrage is a dam that is built across a waterway. The dam has gates that can be opened to allow for the passage of ships.
A barrage can either be built across a natural waterway such as in Sohra in Bangladesh or can be constructed by building an artificial channel and inserting it into an already existing waterway such as in Akosombo which connects the Volta River to Lake Volta located in Ghana, Africa.
What are the main types of barrage?
There are three main types of barrage that are built across water ways. They include:
- Channel Barrage. This is the most common type of barrage and is built as a dam across a waterway with gates attached to it so that ships can pass through freely by going underneath the dam without stopping or being impeded from flowing through the canal.
The construction process for this type of barrage usually includes digging a channel between two existing waterways.
The gates are then placed on either side on the new channel so that ships can pass through freely while also allowing water to flow through.
These types of barrages are usually built along wide, deep channels and can be used to help create a ship channel for ships to pass through while not impeding the movement of other ships that may be passing.
- Embankment Dam. This type of barrage usually involves creating a dam by piling up earth at the proposed waterway that is usually along a wide channel.
The earth will then be covered with asphalt and concrete so that it can lower the chances of erosion or erosion events.
These barrages are usually built where there is a shallow waterway that is not deep enough to hold an actual dam.
They are also used when the opening and closing of gates for ships passing through is not required which would fall under channel barrages.
- Spillway Barrage. This type of barrage is usually built to help control water levels so that they do not flood a particular area, create a fast moving current and cause currents to stir up sediment that can cause erosion.
Where does barrage are built?
Barrier barrages can be found around the world and are mostly built-in areas where river systems flow together and it helps to prevent damage caused by flooding and erosion.
Countries that have natural barriers to natural water flow such as sand dunes or rock formations usually have more barrages built than countries that do not have any natural barriers.
How is barrage used?
Barriers are usually only used to help prevent erosion and maintain a natural water flow. They should not be used to create flooding or trap sediment in water because doing so would cause permanent damage to the barrier and surrounding areas.
What are the key functions of barrage?
Barriers exist to help prevent damage due to water flow and erosion. They are also used to create a smoother flow of water for smaller vessels and slower moving objects such as boats, pleasure crafts and smaller types of commercial vessels.
Barriers can also be used in combination with other structures such as locks and boats can traverse over them without having to stop or slow down their speed.
What are the key benefits of barrage?
There are several benefits that can be obtained by using barrage type dams depending on the specific use. They include:
How is barrage used?
Barrier barrages are usually used to help prevent damage due to water flow and erosion. They are also used to create a smoother flow of water for smaller vessels and slower moving objects such as boats, pleasure crafts and smaller types of commercial vessels.
Barriers can also be used in combination with other structures such as locks and boats can traverse over them without having to stop or slow down their speed.
What are the advantages of barrage?
There are several advantages that can be obtained by using barrage type dams depending on the specific use. They include:
- They can help control the flow of water across a river
- They can help prevent erosion and sediment build up
- They can help create a deeper channel for a river that used to be shallow
- They are used to prevent flooding in areas where waterways are naturally shallow
- It can reduce the amount of silt or sediment that is trapped in areas where natural bodies of water have very slow movement. This is done by creating gates that allow excess water and sediment to be drained off without changing the movement of natural bodies of water.
