The primary objective of ground water regime monitoring  is to record information on ground water levels and quality through representative sampling in space and time. Board regularly monitors ground water level through a network of ~ 15640 ground water observation wells located all over the country. Water level is measured four times in a year i.e in the month of January, April/May, August and November and ground water quality samples are collected once in a year i.e during April/May.

 Ground Water Level Scenario in India  during January- 2007

          A perusal of depth to water level map of India for the January 2007 reveals the following:

          In sub-Himalayan area, north of river Ganges, generally the depth to water level ranges from 2-5 meter below ground level (mbgl). Isolated pockets of shallow water level less than 2m has also been observed. In the eastern part of the country in the Brahmaputra valley water level generally ranges from 2-5 mbgl, except in isolated pockets where depth to water level is less than 2 mbgl. However, in Upper Assam, isolated pockets of deeper water level, 5-10 mbgl have been observed. In major parts of Indus basin, depth to water level generally ranges from 10-20 m.bgl. In the western part of the country covering states of Gujarat and Rajasthan, deeper water level is recorded in the range of 10-20 m.bgl. Depth to water level more than 40m has also been observed in Jodhpur, Churu, Jalore, Nagaur, Jhunjhunu and Jaipur districts of Rajasthan. In the West Coast, water level generally ranges from 5-10 m . Western part of Maharashtra recorded water level of less than 5m. In the east coast i.e. coastal Andhra Pradesh and Orissa, generally the water level ranges between 2-5m. However, isolated pockets of water level less than 2m have also been recorded. In eastern part of Ganga basin, water level in general ranges from 2-5 mbgl. Eastern most part of West Bengal recorded water level in the range of 5-10 mbgl. In Central India, water level generally varies between 2-10 mbgl. except in isolated pockets where water level is more than 10 mbgl. In the peninsular part of country, generally water level ranges between 2-10 mbgl except in pockets where water level ranges from 10-20m bgl. Isolated patches of water level in the range of 20-40m and more than 40m have also been observed in pockets.

A comparison with previous year’s water level for the same season ( January,2006) reveals that there is mixed (rise/fall) trend in water levels in the entire country. The fall in water level is observed mostly in the states of Andhra Pradesh, Karnataka and Tamil Nadu. In Andhra Pradesh, there is general fall in water level in major part of the state. More than 25% of the monitoring wells show fall in water levels of more than 2m. Fall of 2-4m has been observed in various parts such as Khammam, Karimganj, Rangareddy, Nalgonda and Mahbubnagar districts of Telengana region, Prakasam and Nellore districts of Coastal region and in parts of Rayalseema districts. In Karnataka more than 2m fall in water levels is observed in parts of Raichur, Bellary, Chitradurga, Chikmaglore, Mandya, Kolar, Simoga, Haveri, Gadag, Kopal, Gulbarga, Mysore, Banglore urban and Tumkur districts. In Tamilnadu, the fall in water level in the range of 2-4 m bgl has been observed in 10% of the wells analyzed and noted in all the districts except in Kanyakumari, Nagapattanam, Nilgiri and Tuticorin districts.

Water level fluctuation between Jan’07 and average water level (1997-2006) indicates that more than 20% of the monitoring wells in the state of Punjab, Haryana, Chandigarh, Bihar, West Bengal, eastern parts of Madhya Pradesh and eastern Rajasthan show a decline in water level of more than 2m. In hilly terrain of West Bengal, Assam, parts of Meghalaya, Tripura and Jharkhand, there is rise in water levels by  more than 2m. In Karnataka fall has been observed in major parts.  In Andhra Pradesh, rise of water level more than 4m is noticed in Adilabad, Karimnagar, Medak, Nalgonda, and Mehbubnagar districts and in small isolated areas in West Godavari, Cuddapah and Chitoor districts. In the state of U.P, rise in water level upto 2m is observed in parts of Aligarh, Bahraich, Balrampur, Bijnour, Chandoli, Jhansi, Maharajganj districts. Fall of more than 4m is observed in Agra, Allahabad, Banda, Jhansi, Kanpur, Mathura, Pratapgarh, Moradabad and Varanasi districts.

Fig.1 Depth to Water Level for January 2007

Fig.2 Annual water Level Fluctuation- ( January06- January 07)

Fig.3 water Level Fluctuation During January 07-Decadal Mean