India's groundwater crisis

India's groundwater crisis

This is the Ganges River in India. Compared with the surface water that can be seen to be clear and turbid, the situation of India's groundwater hidden in the strata is even more grim.

India is the world's largest groundwater user, with an average annual groundwater consumption of 230 billion cubic meters, accounting for more than a quarter of the world's total groundwater consumption. In India, 60% of irrigated agriculture and 85% of drinking water supply rely on groundwater, which is India's lifeline.

Compared with seriously polluted surface water

People are more willing to use groundwater that is not polluted

(The car is the groundwater that the government has concentrated on extracting)

However, in recent years, India's groundwater has not only become less and less, but the water quality has deteriorated. What exactly caused this?

According to the hydrogeological environment, India's groundwater aquifers can be divided into six categories. The two largest categories are hard rock aquifers and loose impact aquifers.

The former is mainly distributed in the central region of the Indian peninsula, accounting for about 65% of the total surface area of ​​India's aquifers. As its name suggests, these aquifers are covered by hard rock layers, with poor permeability and low water storage capacity. Even if there is precipitation recharge, they will dry up quickly.

The latter flows on the vast Indus-Ganges-Brahmaputra Plain and is the source of 70% of India's available groundwater. The groundwater here is not only abundant but also of good quality, and hot springs gush out in many places.

In addition, there are underground aquifer types in different geological environments such as the mountain system in the Himalayas, the soft sedimentary system and hard sedimentary system in the dry land in central India, and the volcanic system in the western region. These groundwaters are highly heterogeneous.

In 2020, India's total annual groundwater recharge reached 436 billion cubic meters, more than 3,300 times the maximum annual runoff of the Ganges. Among them, precipitation from the atmosphere accounted for nearly 64% of the total groundwater recharge.

Affected by the southwest monsoon, precipitation recharge in most parts of India comes from June to September each year, and groundwater is no exception. The groundwater level in some areas can differ by more than 5 meters before and after the monsoon. Last year, the groundwater level in Asthawan, Noorsarai and Rahui in Bihar, which benefited from monsoon precipitation, rose by as much as 9 meters.

However, India's groundwater is not always so abundant, and of course not all of it can be mined. Some are too deep, some have complex geological structures, and only about 91% can be mined. Among this part of the exploitable groundwater, only 70% is "safe", and the remaining 30% is in "overexploited", "critical" and "semi-critical" states.

For a large water-consuming country like India, even unsafe groundwater is worth mining. In Delhi, Haryana, Punjab and Rajasthan in northwest India, the groundwater development rate exceeds 100% - the annual groundwater consumption is much greater than the annual recharge. In Himachal Pradesh, Tamil Nadu and Uttar Pradesh, the groundwater development level can also reach more than 70%, and the development efforts are also relatively large.

In recent years, due to excessive exploitation of groundwater by humans and low recharge rates, aquifers in many parts of India are facing the crisis of overexploitation, and their current situation continues to challenge the psychological defenses of Indians.

Ideally, when water pollution conflicts with economic development, economic development needs to give way to water resource protection, but the reality is often the opposite. In India, 89% of groundwater is used for irrigation, 9% for domestic water, and 2% for industrial production. It can be seen that irrigation is the biggest part of all groundwater use.

In the past 40 years, with the continuous advancement of the green revolution and the continuous growth of the population, intensive water use and fertilizer input have become the two major highlights of India's agricultural production. The planting intensity and irrigation area in various places have shown an upward trend, resulting in excessive exploitation of groundwater.

In agricultural planting, the most water-consuming crops are water-intensive crops such as wheat and rice. The huge population has forced India to plant these crops on a large scale, thus consuming a lot of groundwater resources.

It is estimated that by 2025, large areas in northwest and southern India will face a groundwater supply crisis, which may lead to a 20% drop in total crop production in India, and a 68% drop in severe areas, threatening the food security of millions of people.

In addition to over-exploitation and waste, the pollution of groundwater in India is also very worrying.

Normal groundwater is usually colorless and tasteless. After infiltration and filtration through rock formations, the water quality is also good. Some are also rich in minerals and trace elements that are beneficial to the human body. Moreover, compared with surface runoff, groundwater stored in the gaps of geological media is generally not easily polluted. However, once it is polluted, it will be a big trouble. It will not only endanger people's health, but also affect the stability and sustainable development of society.

At present, nearly 60% of the areas in India have problems with groundwater supply and quality. According to statistics from the Indian Assessment Committee, the arsenic content in groundwater in 68 areas of 10 states, including Haryana, Punjab, Uttar Pradesh, Bihar, Jharkhand, Chhattisgarh, West Bengal, etc. is too high.

If you drink it for a long time, it may cause chronic arsenic poisoning, leading to changes in pigmentation, skin damage, and even cancer. In addition to high-arsenic water, groundwater problems such as high-fluoride water, bitter and salty water, and high-iodine water are also very prominent in India.

In addition, the current situation of groundwater in India is worsened by the non-standard landfills, septic tanks and fertilizer and pesticide discharges from humans. In the long run, regional complex pollution that is difficult to solve will gradually form, eventually affecting the water quality of surface rivers and destroying the entire water cycle.

With the intensification of global climate change and the impact of human production activities, nearly half of the people in India are currently facing a water crisis, and 200,000 people die every year due to lack of access to clean water. By 2025, the per capita available water will continue to decline to about 1,400 cubic meters, and by 2050 it will further decline to 1,250 cubic meters.

Since the problem is so serious, what measures has India taken to manage groundwater resources? Is there any effect?

First of all, someone has to manage it. At present, India has four major institutions including the Central Water Commission (CWC), the Central Groundwater Administration (CGWB), the Central Groundwater Council (CGWA) and the Central Pollution Control Board (CPCB), which manage groundwater resources throughout India.

The second is to formulate a governance framework. In 1882, India introduced the Easement Act, which details non-possessory rights of property and is still in use today. The law provides that those who own land in India are free to develop and treat the surface and groundwater resources in their area. This law has become one of the stumbling blocks for India to regulate groundwater extraction.

In 2011, the Indian government issued the Model Bills for Groundwater Management. The bill clarifies the use of groundwater and gives states and communities the power to regulate groundwater use. Two years later, the Indian government updated the National Water Policy, clarifying key principles for groundwater demand management, efficiency, infrastructure and pricing.

The most recent major groundwater plan is the Atal Bhujal Yojana plan proposed in 2019. The plan is expected to help water-scarce villages in seven states, including Haryana, Gujarat, Karnataka, Madhya Pradesh, Maharashtra, Rajasthan and Uttar Pradesh, get rid of the groundwater crisis and use water safely within five years.

The introduction of these bills and plans has alleviated the current situation of over-exploitation of groundwater in India to a certain extent.

Compared with the comprehensive assessment in 2017, the total annual groundwater recharge in India increased by 4 billion cubic meters in 2020. The total amount of groundwater that can be exploited throughout the year has also increased by 5 billion cubic meters, and the annual groundwater extraction for irrigation, household and industrial purposes has also decreased by 4 billion cubic meters. These positive development trends are attributed to India's increasingly detailed survey methods for groundwater resources and increasingly accurate parameter simulation operations.

The current Indian Central Groundwater Board (CGWB) will collect data from 22,730 groundwater level monitoring points across the country in January, April or May, August and November each year, and the states will also conduct regular monitoring and assessment based on regional water level cycle differences. Using these assessment data to draw aquifer maps and adopt engineering controls, Indian states will gradually achieve sustainable management of groundwater resources.

For example, in Andhra Pradesh, which is adjacent to the Bay of Bengal in the south, the government divided the state into 667 assessment units based on the characteristics of the rock formations and classified and assessed the groundwater resources. In addition, water-saving activities called Neeru-Chettu and water-saving irrigation models such as micro-irrigation were promoted. These operations have increased the groundwater resources in Andhra Pradesh by 300 million cubic meters in five years.

Today, many states in India have adopted an assessment model similar to that of Andhra Pradesh. These refined operations have significantly improved the groundwater in various states in India, at least in terms of data.

In the future, sustainable dynamic management of groundwater will also be the main goal of India to protect groundwater resources. However, for a populous country like India, where the level of groundwater resource management needs to be further improved, there is still a long way to go to achieve this goal.