The sharp fall in the use of canal water for irrigation has resulted in the steep decline in the ground water table in Punjab.
The fact came to light in the latest report of the Central Ground Water Board titled "Water Quality Issues and Challenges in Punjab".
The report accessed by HT categorically stated that there has been a reduction of over 35 percent in canal-irrigated area since 1990, due to reduction in the water capacity of canals. The situation resulted in increase in the number of tubewells, which were used for irrigation.
At present, there are 12.32 lakh tubewell connections in the state as compared to 1.92 lakh in 1970 and the area under irrigation by ground water in the state has increased from 55 percent to 73 percent.
The report said that the use of ground water at present in the state is 145 percent and out of 137 blocks, 103 blocks are overexploited, 5 blocks are at a critical stage, 4 at a semi-critical stage and only 25 blocks are in the safe category.
Due to excessive use of water for agriculture purposes, especially for paddy, the water table is depleting at an alarming rate in the entire state, except in the low-lying pockets in southwestern districts.
The report also blamed the excessive use of fertilisers, pesticides, insecticides, herbicides for excessive use of water mentioning that the ground water table was at an alarming stage in the Malwa region (cotton belt), which accounts for nearly 75 percent of the pesticides used in the state.
The use of N & NPK fertilisers has also increased 8 times since 1971.
Stressing upon the need to encourage canal water irrigation, the report said that there has been continuous rise in water levels in the canal command areas and it has increased after the development of the new canal system.
"The areas experiencing declining water level trends in both pre- and post-monsoon periods are the central and northwestern parts of the state as about 66 percent of the area shows the declining water level trend in pre-monsoon period while 59 percent of the area shows the decline in the post-monsoon period", reads the report.
As per the report, the average annual rainfall has also decreased during the last two decades by 45 percent from 755 mm in 1990 to 418 mm, but the irrigated area of the state has increased from 71 percent in 1970-71 to 97.4 percent, as compared to 40.5 percent national average.
Though the state has a fully developed network of a planned irrigation system consisting of about 14,500 kms of canals, distributaries and minors, but the area irrigated by canals dwindled from 12,860 sq km in 1970-71 to 11,100 sq km, said the report. The surface water resources cover only 29 percent of the total irrigated area, while the area under irrigation by ground water through tubewells has increased to 73 percent.