The story of water is intriguing and forms the basis for human interpretation of science. Rainfall triggers the trickling streams from several pockets which merge into larger ones like the speeding river which goes on to join the mighty ocean. This journey of water from the cloud to the open ocean is not without obstacles; especially in the new age when there are bulk walls in the form of dams that block the free flow of water.
Why dams?Dams came into existence early as humans were evolving. They have been an essential invention to ease human life. A free flowing channel of water is blocked with boulders/rocks or finely engineered walls to not waste water and to make optimum use of it. There are several positives to a dam. But, as in every case, they carry a certain degree of damage too. For most of us living in urban spaces, we have very little understanding of the forest terrain and the changes that happen there.
For human needs, we alter the face of any terrain or natural resource and stretch it until we get what we need. The benefits that one gets from a dam are many — if water continues to run to the oceans whenever it rains, there is limited or no storage of fresh water, thereby leading to dry days during summer. To get around this problem came the concept of harvesting fresh water. That is, fresh water is stored and not allowed to run down the stream, uncontrolled. These structures came to be known as “Check Dams” which regulated the flow of water and ensured its conservation. With water getting stored behind these walls there came into existence a lake.
These lakes are artificial and change the entire ecosystem. Now, there is standing water in large quantities restricted by a wall, and thereby creating a huge pressure on the ground below. Sheets of water in enormous quantity standing still, adds weight to the ground, and this could trigger plate movements underground.
In the past, there have been tremors and mild earthquakes in regions where there are large dams. With advanced technology, care is being taken to ensure safety measures are in place to build earthquake-resistant and balanced dam structures that do not affect the surrounding neighbourhood. With water in the dams and the pressure it creates, we can harvest electricity by running it through turbines. thereby transforming energy from one form to another. The speeding water is stopped and its speed in force is now used to run a turbine. This then produces heat which lights our homes. Hydroelectricity is one of the main reasons why dams are built. This has benefited several million people.
Water conservation, energy production and beautiful locales for tourism are advantages that a dam enjoys; however, the irreversible damage that is caused to the ecosystem is a cause of worry. By cutting down large forests and relocating people and animals, we are destroying the livelihoods of some so that a few others can have electricity. In an energy-hungry country like India, finding the balance between conservation and population has always been a tough task. Dams are inevitable and preferred by the development gurus, in a world where it is mostly about what humans want; environment and other life forms are always the forgotten entities.
Some dams in India
TEHRI DAM, Uttaranchal: It is 260 metres high, on the Bhagirathi River with a reservoir capacity of 2,100,000 acre feet.
HIRAKUD DAM, Odisha: It is 60.96 metres high, on the Mahanadi River with a reservoir capacity of 4,779,965 acre feet.
NAGARJUNA SAGAR DAM, Andhra Pradesh: It is 124 metres high, on the Krishna River with a reservoir capacity of 9,371,845 acre feet.
KRISHNARAJASAGAR DAM, Karnataka: It is 125 metres high, on the Cauvery River with a reservoir capacity of 1, 134, 998 acre feet.
KOYNA DAM, Maharashtra: It is 103.2 metres high, on the Koyna River with a reservoir capacity of 2, 267,900 acre feet.
