Recharging groundwater by water-harvesting measures
- November 13, 2022
- Posted by: OptimizeIAS Team
- Category: DPN Topics
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Recharging groundwater by water-harvesting measures
Subject: Geography
What is an Aquifer-
- An aquifer is a body of porous rock or sediment saturated with groundwater.
- Groundwater enters an aquifer as precipitation seeps through the soil. It can move through the aquifer and resurface through springs and wells.
India and Groundwater-
- India is the largest user of groundwater in the world, extracting groundwater to 253 billion cubic meters (bcm) per year.
- It is about 25% of the global groundwater extraction.
- Out of the total of 6584 assessment units, 1034 have been categorized as ‘Over-exploited’, 253 as ‘Critical’, 681 as ‘Semi-Critical’ and 4520 as ‘Safe’.
- The remaining 96 assessment units have been classified as ‘Saline’ due to the non-availability of fresh groundwater due to salinity problems.
Availability of Water:
- India has about 1123 billion m3 of water resources available, out of which 690 bcm is surface water and the rest 433 bcm is groundwater.
- Out of the total groundwater available, 90% of it is used for irrigation purposes which is mainly for agricultural purposes.
- The remaining 10% accounts for domestic and industrial purposes combined.
Water Crisis in India:
- According to the Composite Water Management Index (CWMI) report released by the NITI Aayog in 2018, 21 major cities (Delhi, Bengaluru, Chennai, Hyderabad and others) are racing to reach zero groundwater levels by 2020, affecting access for 100 million people.
- The CWMI report also states that by 2030, the country’s water demand is projected to be twice the available supply, implying severe water scarcity for hundreds of millions of people and an eventual 6% loss in the country’s GDP.
- Maharashtra and nearly half the country is facing an acute water shortage.
- Besides Maharashtra, Tamil Nadu, Karnataka, and Rajasthan, parts of Gujarat, Punjab and Haryana are facing a water shortage of unprecedented levels.
How to harvest the rainwater-
- Catchment– Used to collect and store the captured rainwater.
- Conveyance system – It is used to transport the harvested water from the catchment to the recharge zone.
- Flush– It is used to flush out the first spell of rain.
- Filter – Used for filtering the collected rainwater and removing pollutants.
- Tanks and recharge structures: Used to store the filtered water which is ready to use.
- The process of rainwater harvesting involves the collection and storage of rainwater with the help of artificially designed systems that run off naturally or man-made catchment areas like- the rooftop, compounds, rock surfaces, hill slopes, artificially repaired impervious or semi-pervious land surfaces.
Several factors play a vital role in the amount of water harvested are:
- The quantum of runoff
- Features of the catchments
- Impact on the environment
- Availability of the technology
- The capacity of the storage tanks
- Types of the roof, its slope and its materials
- The frequency, quantity and quality of the rainfall
- The speed and ease with which the rainwater penetrates through the subsoil to recharge the groundwater.
What are the Initiatives Taken by the Government?
Central Government:
- It is promoting the concept of conjunctive use of surface and groundwater based on the village/gram panchayat level water security plan prepared in a scientific manner through the participation of communities/stakeholders.
- Atal Bhujal Yojana (Atal Jal):
- It is a Rs. 6000 crore Central Sector Scheme with World Bank assistance, for sustainable management of groundwater resources with community participation.
- Jal Shakti Abhiyan (JSA):
- It was launched in 2019 in 256 water-stressed districts in the country to improve water availability including groundwater conditions in these areas.
- It has a special emphasis on the creation of recharge structures, rejuvenation of traditional water bodies, intensive afforestation etc.
- Aquifer Mapping and Management Programme:
- The CGWB has taken up Aquifer Mapping and Management Programme.
- The program is aimed to delineate aquifer disposition and their characterization for the preparation of aquifer/area-specific groundwater management plans with community participation.
- Atal Mission for Rejuvenation and Urban Transformation (AMRUT):
- The Mission focuses on the development of basic urban infrastructure in the AMRUT cities, such as water supply, sewerage & septage management, stormwater drainage, green spaces & parks, and non-motorized urban transport.
State Government:
- Mukhyamantri Jal Swavlamban Abhiyan’ in Rajasthan,
- ‘Jalyukt Shibar’ in Maharashtra,
- ‘Sujalam Sufalam Abhiyan’ in Gujarat,
- ‘Mission Kakatiya’ in Telangana,
- Neeru Chettu’ in Andhra Pradesh,
- Jal Jeevan Hariyali in Bihar,
- ‘Jal Hi Jeevan’ in Haryana,
- Kudimaramath scheme in Tamil Nadu.