A dam is a structure made of bricks, clay, concrete etc. over a river or a stream to control its water flow. This structure helps in holding back the water flow and subsequently forms artificial lakes or reservoirs.
These artificial lakes or reservoirs serve a handful of purposes; they help in irrigation, industrial usage of water and household usages. Moreover, these lakes help to prevent floods by controlling the water flow.
Even though lakes are essential, they often affect the biodiversity and natural flow of water. Thus, alternatives to big dams are being considered and planned to maintain the natural course of actions.
Big dams have their advantages as they aid in multiple regions and overall development of surrounding areas. However, it has its drawbacks too. Thus, alternatives to big dams are a need of the hour to save ecosystems.
Conserving water and efficient use of water is touted as one of the primary solutions. Additionally, water recycling is another alternative to large dams. However, the acceptance of these processes may take time, but they can save the ecosystems.
An alternative to big dams can restore the ecological balance of a river and its surroundings.
Dams play an essential role in distributing water as per requirements. Moreover, it helps in irrigation by supplying the needed water and prevent flooding of agricultural lands. Additionally, industries and families living around the area are also benefitted from a dam and its controlled water flow.
Dams aids in generating hydropower. When the water is released via gates and passed through turbines, the force of water generates electricity. Moreover, hydropower is a source of renewable energy. Additionally, it has a high demand around the world.
Apart from distributing water and generating electricity, dams play a crucial role in controlling the flood. Certain dams are purpose-built to manage flood, and they can reduce it by almost 30%-50%. On the other hand, some dams are equipped with this secondary function. With appropriate planning, they can prevent areas from flooding.
Dams are often built to contain various types of wastes. These dams do not let such waste to mix in the river water and contaminate it.
Artificial lakes created by dams promote various recreational activities. Individuals can take their boats for a trip, or go for a fishing trip, etc. Several tourism prospects can be developed surrounding a dam.
These are some primary purpose of building a dam. However, the adverse effects of large dams and reservoirs are numerous and varied. Moreover, it directly impacts the chemical and physical properties of a river and its ecosystem.
The walls of such dams hinder fish migration. It totally or partially separates spawning habitats from rearing habitats. Additionally, these large dams tap various sediments that are essential for the survival of fishes and other aquatic creatures that live downstream.
Another significant impact of dams is that they transform a free-flowing ecosystem of a river or a stream to an artificial slack-water habitat. Sudden changes of temperature, oxygen level, the chemical composition of the water, etc. often leave an adverse effect on various species.
Aquatic creatures that evolve in a particular ecosystem can face the threat of extinction because of this sudden change. Additionally, these reservoirs usually house different invasive and non-native species, which harms the typical ecosystem of a particular river. Thus, the demand for an alternative to big dams is only logical to save such ecosystems.
Apart from the ecosystem of rivers, these dams have a substantial environmental impact on lives around particular rivers. The changes in a river’s flow along with sediment transportation alters the overall ecosystem surrounding that river.
Over time, the demand for alternatives to big dams has also increased as its adverse effects have come forward.
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1. What is the largest Dam in India?
Ans. Tehri Dam in Uttarakhand is the largest dam in India. It has a height of 260 meters and length of 575 meters. Moreover, it can generate up to 1000 MW of hydropower.
2. Which is the oldest Dam in the world?
Ans. Jawa dam in Jordan is the oldest dam in the world. It dates back to 3,000 BC. The remains of this dam are still there, 100 km from the capital Amman.
3. What is the alternative to big Dams?
Ans. The alternatives to big dams are water conservation and recycling water. Proper utilisation of these methods can offer better solution than that of conventional dams.