it has also been noted that the rate of exploitation of groundwater is more than recharge across India. From 1980 onwards the share of use of groundwater becoming higher and the depletion of groundwater resource due to less recharge become critical. Excessive use of groundwater in agricultural sector creates hydrological imbalance and affects sustainability of the natural resources and water quality is also deteriorating with various contaminants such as arsenic, fluoride etc.
The number of groundwater schemes has increased in India rapidly, while that of surface water schemes has gone down across the country between 2006-07 and 2013-14, resulting in growing dependency of farmers on subsurface resources. The number of surface water schemes such as flow and lift irrigations, however, has dropped from 1.24 million to 1.19 million. Groundwater still accounts for the lion ' s share 94.5 % of all the minor irrigation schemes in the country. At the national level, groundwater schemes are increasing but surface water schemes are declining.
Across India more than half of wells show declining groundwater levels. Declining surface water availability is forcing desperate and agitated farmers to increase groundwater use. If current trends continue northern India will face steadily declining agricultural outputs and severe shortages of potable water. Parts of Delhi
Newsletter No. 63; IRBMS consistently suffer serious water shortages every summer. The crisis, however, is not isolated to the north; it is spreading slowly to other regions. A recent decade-long study of wells in Maharashtra, a west-central state, found that 70 % show a decline in groundwater levels.
In addition to scarce supply, water quality is a serious threat. India’ s groundwater reserves are not only overexploited but also contaminated. The parliamentary report stated that deep-level groundwater is contaminated by sewage, fluoride, arsenic, and uranium. Incidence of arsenic contamination, as measured by number of affected habitations, doubled between 2013 and 2016. In early 2017, the Union Minister for Water Resources River Development and Ganga Rejuvenation stated that the need to raise awareness about arsenic contamination is urgent. In many West Bengal villages, residents have been drinking arsenic-contaminated water unwittingly for decades.
In India Groundwater is under constant threat from both agricultural and urban uses. The rates of natural replenishment are declining steadily threatening the sustainability of aquifers in the Indo-Gangetic Basin, which constitute one of Asia’ s most densely populated and agriculturally productive regions. The Indus Basin, which accounts for a significant share of India’ s
8
Integrated River Basin Management Society