Earth Day : India in search of hidden sources of water

The search for fresh sources of water to meet the expanding need of a burgeoning population has prompted the water resources ministry to conduct an extensive mapping of the country's aquifers ahead of the environment & earth day 2011. The proposed mapping, backed by the Planning Commission, will include a search for palaeowater or groundwater that has remained hidden for several thousand years.

Interestingly, palaeowater aquifers as a potent source for freshwater was discovered recently while conducting hydrological experiments. These aquifers lie hidden deep into the earth and cannot be easily located. Nevertheless, the quality of water extracted from such confined and deep sources is better in comparison with water obtained from the shallow or first- level aquifers which may be contaminated.

Besides, the shallow aquifers located 30 to 40 meters below the earth are over exploited and hence there is an urgent need to look for alternative sources of freshwater.

“ The first- level water is being dried up or getting contaminated,” said Bhishm Kumar, scientist and head, hydrological investigation division, National Institute of Hydrology (NIH) , Roorkee, under the water resources ministry.

The aquifer mapping, which is likely to be carried out by the Central Ground Water Board, will help in identifying dynamic aquifers at greater depths that can be utilised for drinking and irrigation.

“ There may be thousands of palaeowater sources in India, but no systematic survey has been conducted yet to find this out,” Kumar said.

A study conducted by NIH to ascertain the intrusion of seawater into groundwater in the Krishna-Delta region of Andhra Pradesh found that water samples in the region were more than 25,000 years old, according to a paper published by the institute in December last year.

Similarly, an environmental isotope study to ascertain the age of water in the Bhadka- Bheemda area in Barmer, Rajasthan in 1996, confirmed the existence of palaeowater which was between 4,000 and 9,500 years old.