Tuesday, February 24, 2009

Utilization of Rain Water

Rajya Sabha 

The average annual precipitation is estimated as 4000 billion cubic Meters (BCM) in the country. After accounting for the natural process of evaporation etc., the average annual water availability in the country is assessed as 1869 BCM. It is estimated that owing to topographic, hydrological and other constraints, the utilizable water is 1123 BCM which comprises of 690 BCM of surface water and 433 BCM of replenishable ground water resources. Rest of the water could be considered to be flowing down to sea. 

National Water Policy states that "water resources available to the country should be brought within the category of utilizable resources to the maximum possible extent". Due emphasis has been laid on non-conventional methods for utilization of water such as through inter-basin transfer, artificial recharge to ground water and desalination of brackish or sea water as well as traditional water conservation practices like rainwater harvesting including roof top rainwater harvesting with a view to further increase the utilizable water resources. 

Storage capacity of about 225 BCM has been created so far. As per present assessment, the total estimated storage capacity of various projects under construction is about 64 BCM. Further, the State Governments have identified various other schemes for investigation and planning and the estimated storage for such schemes is about 108 BCM. The reservoir capacity for storing water is generally governed by topographical and hydrological features. Similarly, the potential for artificial recharge to ground water is considerably influenced by the aquifer characteristics. The National Commission for Integrated Water Resources Development in its report has projected the total storage capacity of about 458 BCM by the year 2050. The potential capacity for artificial recharge to ground water has been assessed as about 36 BCM. 

Due emphasis has been laid on rainwater harvesting including rooftop rainwater harvesting, artificial recharge to ground water etc. by the respective State Governments and Government of India. 

This information was given by the Minister of State for Water Resources, Shri Jai Prakash Narayan Yadav in a written reply in the Rajya Sabha today.

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