Groundwater resources in Kerala have come under increasing stress from rising levels of exploitation and pollution, the first aquifer atlas of Kerala has revealed.
The atlas, compiled by the Central Ground Water Board, estimates the net annual groundwater availability in the State at 6.01 billion cubic metres as on March 2011. The stage of “groundwater development” for the State as a whole has been computed at 47 per cent. The utilisation pattern is, however, uneven across the State, with groundwater-stressed conditions in some parts and sub-optimal groundwater development in some others.
Chittur block in Palakkad district has been classified as overexploited (above 100 per cent), while Malampuzha block in Palakkad and Kasaragod block have been categorised as critical (between 90 per cent and 100 per cent). As many as 23 of the 152 blocks in different districts are classified as semi-critical and the remaining 123 blocks as safe. The document notes that shortage of water for drinking and domestic uses and contamination of water from natural and human cases were felt in different parts of the State in spite of the relatively low level of groundwater development.
Titled Aquifer Systems of Kerala, the atlas has grouped the water-bearing formations of the State into 10 principal aquifer systems and an equal number of major aquifer systems. It has maps depicting various aspects of the groundwater regime, including water levels, chemical quality, status of groundwater utilisation and vulnerability to overexploitation and contamination. It also features information on rainfall distribution, population density, feasibility of the area for groundwater development, artificial recharge and water conservation.
The atlas says Palakkad district has aquifer systems covering 4,480 sq km, the highest in Kerala. Idukki has 4,358 sq km of aquifers and Malappuram, 3,550 sq km. Alappuzha has 1,414 sq km, the lowest area under aquifers. Charnockite, the principal aquifer system in Kerala, covers 17,167 sq km in 13 districts, while Banded Gneissic Complex covers 6,940 sq km in seven districts and Gneiss, 6,047 sq km in 10 districts.
“The atlas lays the foundation for scientific management of groundwater resources in the State in the face of the pressures posed by human activities and environmental and climate change factors. It will help planners and policy-makers in framing strategies for water and food security,” P. Nandakumaran, Regional Director, CGWB, said.
He said the document would provide baseline information for the National Aquifer Mapping Programme to be carried out during the 12{+t}{+h}and 13{+t}{+h}Plan period. Under the programme, the aquifer systems in Kerala would be mapped on a 1:50,000 scale to provide a comprehensive database.
The atlas released last month stresses the need for a long-term monitoring programme to assess the quantity, quality and sustainability of groundwater in aquifers. It is expected to enable Kerala to migrate towards participatory management of groundwater resources involving local communities to overcome the pressures from population rise, urbanisation, industrial activities and human interventions in the ecosystem.
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