Kolar's groundwater over-exploited in Karnataka, report says

Groundwater in Karnataka's Kolar district is most over-exploited, followed by Chikkaballapur district, said a new report on groundwater situation in the country prepared by the Central Ground Water Board.

The report, titled “Dynamic Ground Water Resources Assessment of India”, said that in the state, Kolar is categorised as groundwater over-exploited (199 per cent) district followed by Chikkaballapur (145 per cent) Bengaluru Rural (137 per cent) and Bengaluru Urban district (138 per cent).

The report was prepared by the Central Ground Water Board after assessing groundwater situation across the country covering all the districts.

In Kolar, of the total 399 million cubic meters (mcm) annual extractable ground water, 799 mcm is being extracted. Of the total current annual ground water extraction, total 753 mcm is being used only for irrigation purposes in the district, said the report.

Udupi district is categorised as having the lowest extraction of groundwater, where 143 mcm is being extracted annually against the total annual extractable groundwater of 604 mcm, which is just 23 per cent, said the report.

In Karnataka, a total of 227 units have been assessed, spreading across all districts, in which 130 units were categorised as safe, 35 units were semi-critical, 10 units were critical and 52 were over-exploited, said the report. In the state, 88 per cent of groundwater is being used for irrigation.

Annual groundwater recharge has been assessed as 18.15 bcm (billion cubic meters) and the annual extractable ground water resource is 16.4 bcm. The current annual groundwater extraction is 10.64 bcm and the extent of groundwater extraction is 64.85 per cent.

The total annual groundwater extraction of the entire country has been estimated as 244.92 bcm. Agriculture is the predominant consumer of groundwater resources, with about 89 per cent of total annual groundwater extraction i.e. 217.61 bcm being used for irrigation. Only 27.3 bcm is for domestic and industrial use, which is about 11 per cent, said the report.

The overall stage of groundwater development in the country is 61.6 per cent.The stage of groundwater extraction is very high in Delhi, Haryana, Punjab and Rajasthan, where it is more than 100 per cent, which implies that in these states, the annual groundwater consumption is more than annual extractable resources. In Tamil Nadu, Uttar Pradesh, Karnataka and Chandigarh and Puducherry, the stage of ground water extraction is between 60-100 per cent. In the rest of the states, the stage of ground water extraction is below 60 per cent, said the report.