UPSC 2020 Mains Model 01 (Ans): ‘Water and Related Statistics 2019’, published by the Central Water Commission (CWC), had assessed that the annual replenishable ground water resources of the country (2017) have been assessed as 432 BCM.
According to the report, there are many ways groundwater resources get replenished, including rainfall and other sources. Other sources include return flow from irrigation, recharge from water bodies, canal seepage. However, rainfall continues to be the biggest source of replenished water, contributing nearly 67% of the total annual replenishable resources.
As per the report, fifteen states account for about 90 per cent of the groundwater potential in the country. Uttar Pradesh accounts for 16.2 per cent, followed by Madhya Pradesh (8.4%), Maharashtra (7.3%), Bihar (7.3%), West Bengal (6.8%), Assam (6.6%), Punjab (5.5%) and Gujarat (5.2%).
- The total annual extractable ground water availability of the country has been assessed as 393 BCM.
- Ground water extraction is 249 BCM.
- The largest user of groundwater is irrigation sector.
Groundwater resources have been classified into several categories depending on their status. These categories are: safe, semi critical and over exploited ground water resources.
Punjab has the highest proportion of over-exploited area. Punjab is followed by y Delhi, Rajasthan and Haryana, Himachal Pradesh and Tamil Nadu.
Role of CGWB
UPSC 2020: Prelims & Mains Pointers:
Central Ground Water Board (CGWB) assesses the situation of groundwater in India. To know the exact situation of groundwater resources in India, it has drilled various types of bore holes in the country.
The types of bore holes are Exploratory Well (EW), Pizo Metre (PZ), Observation Well (OW), Slim Hole (SH) and Deposit Well (DW).
It has also built a network of more than 20,000 “National Hydrograph Monitoring Stations. Through these stations it monitors water levels and quality in January, March-May, August and November every year.
It also monitors irrigation potential of the country. Uttar Pradesh and Bihar are the two largest States in terms of potential due to Major & Medium Irrigation Projects.
According to the report prepared by the CGWB, the number of over-exploited units has increased to 1,186 in 2017, from 839 in 2004. In the north, more than 60% of the assessment units in Delhi, Punjab, Haryana and Rajasthan are either over-exploited or critical.