Groundwater is the water that seeps into the ground due to rain and other sources and keeps accumulating underneath. It plays an important role in ensuring food security and agricultural sustainability in the country. The advent of Green Revolution in the 1970s saw a significant increase in the use of ground water, which has so far continued, rather increased, resulting in decrease and decline in water level, wells and other irrigation sources in the long term. Apart from this, ground water is no longer potable due to contamination of water sources.
Figures show that on average, ground water level is declining by one meter every year. Earlier, whereas water was found within 30 meters of ground level, now the situation is such that in many areas water is available only 60 to 70 meter below the ground level.
Despite the continuous decline in ground water level, no proper system of water conservation has been developed in the country. Every year billions of cubic meters of rain water goes waste. According to groundwater experts, given the pace water is being exploited in the country, the level of ground water will go further down in the coming years.
Availability of Water in India
Life cannot be imagined without water, but clean and adequate water is still not accessible to most of the people in India. India receives 90 percent of the water from major or medium rivers. It has 14 major rivers each having catchment area of 20,000 sq. km and above; while there are 44 medium rivers with a coastline between 2000-20,000 sq. kms. Then there are 53 small rivers each with catchment area of 2000 sq. kms.
According to the 2011 census, annual per capita water availability in the country decreased to 1545 cubic meters from 1816 cubic meters as per the 2001 census. At present, this situation is even more worrisome. Scientists believe that by 2050 there will be a 30 percent decrease in the availability of water per person. The World Health Organization (WHO) recommends the availability of 200 litres of water per person per day in urban areas. On the contrary, 140 litres of water is supplied per person per day in the country.
Water resources in India are predominantly dependent on the monsoon. India receives an average rainfall of 4000 BCM (Billion Cubic Metre) every year from the rain, but most of it is vapourized and goes down the drains. Statistics show that a dearth of storage procedure, lack of adequate infrastructure, inappropriate water management have created a situation where only 18-20% of the water is actually used. The remainder just gets wasted, aggravating the problem of ground water depletion.
Causes of Groundwater Depletion
Increase in Irrigated Area
Our country’s economy primarily rests on agriculture. Agriculture contributes 40 percent to the GDP of the country, and accounts for 60 percent of the total export revenues. Also, 60 percent of the country’s population is engaged in agriculture and related work. One of the major reasons for water crisis in the country is that as the area of irrigated land has increased, the level of groundwater has declined. Currently, India has a gross irrigated crop area of 82.6 million hectares (215.6 million acres), which is the largest in the world. As the population increases, the water storage capacity of ponds decreases. In fact, wells and ponds go dry after the water decreases at the ground level.
Unbridled tapping of ground water has made the situation even more alarming. Due to the uninterrupted exploitation of ground water by deep wells and tube wells to meet the shortage of water, the level of ground water is continuously decreasing. In fact, whatever amount of water is recharged into the ground, even more of it is extracted.
Extraction only results in further lowering of groundwater level. The water table dips after tubewells and borewells are dug up indiscriminately. As a result, the level of ground water goes down, and small wells, which are not deeply bored, dry up.
Trees hold the rain water and slowly drop it to the ground, absorbing up to 18 inches of precipitation before gradually releasing it to natural channels and recharging ground water. But the way the forests are being destroyed on the Earth, the problem of ground water depletion is becoming even graver. It is believed that for the last 150 years, the forest equivalent to the area of Greece is disappearing from the Earth every year. And, the trees which are planted to compensate for this loss are too inadequate in number. It is estimated that 13 million hectares of forest are lost every year across the world.
The rain cycle has gone haywire in India, due to melting of glaciers. In fact, the amount of rainfall has reduced over the years. The Gangotri glacier has retreated by over 3 kilometres since 1817 from its original place; it is expected to become even smaller by the end of the 21st century. Around 7 km behind Kedarnath Dham, the Chorwadi glacier has also been retreating. According to scientists, glaciers of the Himalayan region have been melting at an average rate of 131.4 square kilometres (50 square miles) per year. All this may imperil the existence of several rivers of Nepal, India and China. When glaciers melt, they initially contribute more water to the rivers they feed. After this there is a decline in water contributed to the seasonal melt cycle, as shrinking glaciers provide a smaller contribution to the overall river flow. It increases the pressure on the water resources as water levels dip in the rivers they feed.
Ground water plays a key role in sustaining ecosystems. Due to global warming, the threat of climate change is very much on the horizon. The fear is that by 2050, half of the world’s population will be destroyed due to hunger, water and disease. Climate change accentuates water stress as it reduces useable groundwater availability for agriculture globally.
Politics of subsidy
Politics of subsidies has led to volatile extraction of ground water leading to its scarcity. Farmer tends to use water for irrigation without any restriction due to availability of cheap, subsidized electricity, thanks to politics of populism.
Wrong Agricultural practices
In rural India, water scarcity is also the result of untested agricultural practices, such as cultivating more water-consuming crops – paddy, cotton and sugarcane – in areas riddled with water scarcity.
Consequences and Effects of Groundwater Depletion
Contamination of ground water
According to the Report of Central Ground Water Board, more than half of India’s groundwater is contaminated. The report says that at least 276 districts have a high level of fluoride, nitrate is above the safe level in 387 districts, and 86 districts have a high level of arsenic. Bad environmental management system leads to the discharge of toxic water with the result that surface and underground water sources – used for irrigation and domestic operations – have been contaminated.
Due to excessive exploitation of ground water, chemicals lying in the womb of the Earth come up. Toxic substances such as arsenic and fluoride lie dormant in the lower part of the underground ponds. By digging deep tubewells, these chemicals come up and by mixing in drinking water, breed several diseases. For instance, by digging deep wells in the coastal states of Gujarat, and mixing of sea water, the water does not only become unfit for drinking but is also not suitable for irrigation.
Drying up rivers
Major rivers are gradually drying up with excessive tapping of water. Earlier, Yamuna’s water was reach Delhi all through the year, now due to the digging of deep tube-well near the rivers in Haryana and Uttar Pradesh, enough water is not able to reach Delhi. After releasing water from Hathinikund barrage, water is completely absorbed in the soil up to 20-25 km, impeding its flow.
Impact on living organism
Fisheries and turtles are dying in the Yamuna. Pilgrims are unable to find water for bathing. The trees on the river bank are dying. Environment of entire areas is being destroyed.
Ground water level is declining in major states of the country. The mountains are facing acute water crisis. Water bodies are drying up. According to the report of Central Water Board, the way water level is dipping; the day is not far when water will have to be imported.
Among hill areas, Udham Singh Nagar in Uttarakhand has registered 40% decline in water level. The state has also registered decline in water level in Rudrapur, Haridwar, and Dehradun. The same situation prevails in the plain and lowland regions. All this becomes a major cause of migration. People who get exhausted after traversing miles to quench their thirst are forced to leave their villages, increasing further pressure on ground water resources.
Prevention and Solutions of Groundwater Depletion
Limit of water-extraction
To deal with excessive tapping of ground water, maximum depth should be determined in each area. Drilling up to 400 feet can be carried. Prior to it, deep tubewells should be filled up, so that water can be removed only up to 400 feet. Thus, water level will not fall below this.
Change in crop-patterns
Ground water can be preserved by the determination of crop cycle. Low water consuming crops should be grown in not so water-rich areas and where there is high intake of water, high-water consumption crops should be cultivated. Crop should be allowed to grow as per the availability of water in every area.
Protection and enrichment of water resources
In addition, groundwater centres should be set up in each state. Illegal exploitation of ground water should be banned. Tapping the inner water of the land for personal use without any information can cause problems in the future. Water is needed for drinking as well as irrigation, industry, power generation etc. For proper utilization of available water resources for this, their protection and enrichment are also important.
Diverting River Streams
In many countries of the world, the problem of water has been solved by diverting the water of a river on the other side. There has been some work in this direction in India. In Tamil Nadu’s eastern parts, water has been diverted to Periyar. Yamuna’s water has also been diverted towards the western part. The river Sindhu has been flown towards Rajasthan. But there is a need to take concrete steps in this direction at the national level. The Central Government has set up a National River Project, which aims to connect all major rivers together so that availability of water in all areas can be ensured but nothing can be said when the plan will be implemented.
There is a need to deepen old reservoirs along with building new reservoirs. Besides increasing the depth of boring of new tubewells, there is a need to coordinate between geologists and engineers at the time of selection of space.
Several measures need to be taken to protect the earth from the threat of climate change, including undertaking extensive plantation.
Many schemes have been made at the government level for water conservation, but the lack of awareness among the people and due to official apathy, the schemes have so far not been able to achieve the desired level.
How groundwater is recharged?
India receives lots of water in the rainy days. This water can be collected in small reservoirs and dams. Later this water can be used for irrigation and electricity purpose. Conservation and storage of rain water is not only important in terms of the continuous falling ground water level but it can also overcome water shortage. The process of rain water conservation is adopted at many levels from the houses and public places, through natural sources such as ponds and wells. For this, first of all, the list of areas should be prepared where the pools and wells dry out and the water level decreases in the ground in the summer season. In such areas, by creating large reservoirs, the depletion of ground water can be stopped and water can also be provided for irrigation.
Water is the biggest need of the future. If efforts are not made to ensure availability of ground water along with purity of its sources, then we can never be certain that enough water will be saved for our future generations. Among other measures outlined above, community involvement should be ensured in the fight against ground water pollution through public awareness and capacity building campaign. Through the implementation of water conservation structures with appropriate designs to offset the ground water resources of the country, efforts should be made to preserve the ground water by restricting the waterfalls in mountainous areas and restricting the indiscriminate construction of borewells. In order to meet current and estimated water shortages in relation to agricultural needs, climate change strategies should include ground water management.