Water is the most precious natural resource, unfortunately, the world is facing a severe shortage of water as a result of pollution and poor monsoon in many geographic areas. Around the world, many cities have already been declared dry and exhausted. If this continues, species cannot exist due to the severe dehydration. Water is a fundamental necessity for every life-form. India is not an exclusion from this, because many parts of our country is facing an acute shortage of water from the past 2 decades. On the other hand, India is probably the only country with a wide monsoon variation across various parts of the country ranging from extremely dry to the wettest areas. Furthermore, each state differ in the type of reservoirs, sources through which they are receiving water and also the monsoon levels. Apart from monsoon variations, poor management of available water reservoirs is resulting in the water crisis. Many cases, people are not aware of available options through which they can save rainwater which can eventually increase the groundwater tables. In some areas, despite a healthy monsoon, we are failing to store the rainwater. Eventually, this can result in an unexpected shortage of underground water tables resulting in the loss of vegetation cover.
Water pollution in India
As our country chiefly depends upon agriculture, there is an enormous demand for rainwater. This is especially true in the open-field agriculture method where a lot of water is being dried out by sunshine. Despite the fact that; the rainwater is being collected, it is hardly being used as the majority of the collected water is polluted as a result of sewage water, industrial effluents, agricultural wastes such as pesticides. Furthermore, dams, canals and other forms of water reservoirs are poorly maintained in many states of India. Although the idea of large scale water projects such as dams and canals was introduced by British people but many mega-projects were left unfinished when they left India. From the 1970s, people once again started the local irrigation methods, and the government has also increasingly took over the administration of these systems.
Water dams -Why we need dams?
Damsare an essential part of the water reservoir system as the stored water is used at times of crisis. They serve a vital role by evenly distributing across wide landmasses. Dams have the advantage of pushing water into the geographic locations that have poor rainfall. In addition, large-sized dams assist in the production of electricity with the same water that is being used for farming. India`s dam water is being distributed through the canal systems. AS many canals are being rightly placed above the sea level, they are capable of transferring a large amount of water to the greater distances. But building dams incur a lot of one-time investment, the political pressures and the different opinions of the people regarding where to build dams is causing problems. If the dams are being planned near the residential areas, people lose their houses. Some of the examples of this kind are the construction of Tehri Dam on the river Ganga and the protests by the Narmada Bachao Andolan (‘Save the Narmada Movement’) about raising the height of the Sardar. They have opposed because of the following reasons
1. Social problems have Rosen because the government has displaced a large number of inhabitants to build the dam. The government has failed to pay adequate compensation or rehabilitation for those inhabitants.
2. Economic problems have started because the contractors and officials have involved in laundering public money.
3. Many environmental issues araised causing a great loss of biological diversity due to the enormous deforestation.
Water harvesting is a scientific method help to preserve the quality of the soil. Water harvesting help in retaining the levels of biomass production. Biomass is the total plant or animal products found in a specified geographical area at a given point of time. Water harvesting methods help to manage the severe water shortage as well as it creates a balance in the ecosystem, this is because the water-harvest system is adapted scientifically. Water harvesting help to provide safe and hygienic drinking water as well as water for irrigation. A good water harvesting strategy can increase the underground water tables. By using water harvesting system, we can reduce stormwater discharges, urban floods, overloading of sewage treatment plants and also we can reduce seawater ingress in coastal areas.
Water harvesting can be carried out through the following ways
Capturing runoff from rooftops during the rainy season
Capturing runoff from local catchments
If possible capture the seasonal floodwaters from local streams
Preservation of water through watershed management
In general, water harvesting is the activity of direct collection of rainwater. The rainwater collected can be stored for direct use or can be recharged into the groundwater. Rain is the first form of water that we know in the hydrological cycle, hence is a primary source of water for us. Rivers, lakes and groundwater are all secondary sources of water. In present times, we depend entirely on such secondary sources of water. In the process, it is forgotten that rain is the ultimate source that feeds all these secondary sources and remain ignorant of its value. Water harvesting means to understand the value of rain and to make optimum use of the rainwater in those places with good rains. In India, there are a wide variety of harvesting systems, the following table has some of the examples of water harvesting projects;
Khadin, tanks, nadis
Madhya Pradesh and U.P.
Delhi and surrounding areas.
Advantages of the water harvesting system
It is easy to maintain as we are utilizing the natural rain instead of extracting from the underground level.
It helps to reduce the water bills as we do not install an underground pumping system, instead, we are allowing water to flow from highland area to low land area.
Water from the water harvesting is most suitable for irrigation as it is not treated with any reagents.
It reduces pressure on the groundwater so that we can save underground water levels.
By collecting rain, we can reduce floods and soil erosion.
This water can be used for many non-drinking purposes.