TR(BR)-120 : Effect of water table depth on recharge due to rainfall

Abstract

The earlier practice of planning surface irrigation without much consideration of ground water status has been often resulted in waterlogging and salinity problems in the command areas after a time due to gradual rise of ground water. Even where due to availability of good natural or artificial drainage, waterlogging and salinity problems are not likely to result, the independent planning leads to loss of opportunity for mopping up the losses from surface irrigation for benefit of the command area.

The upland alluvial valley of Narmada river in Madhya Pradesh is one of the most promising area for development of its surface water and ground water resources. Ground water, till recently, was the main source for irrigation and the area recorded a phenomenal rise in the number of tube wells during the last decade. Also, a new fillip has been given to the development of surface water resources. Bargi dam, the longest masonry and earthen dam in Madhya Pradesh, has been constructed across river Narmada with a network of canal system for surface irrigation and power generation. The Left Bank Canal (LBC) is 137.2 Km long and designed to irrigate about 1 .57 lakh hectares of land in Jabalpur and Narsinghpur districts of Madhya Pradesh. The command area forms a part of Narmada alluvial valley which is quite rich in its ground water resources. A network of branch canals and distributaries are being constructed extending upto river Narmada to achieve the targeted area under surface irrigation. In view of the hydrogeological setup of the area, it is apprehended that with a widespread canal irrigation, problems of waterlogging followed by salinity hazards may crop up in the area in the long run. The advent of surface irrigation may also have a dampening effect on the present development of ground water resources because of its availability at lower tariffs, thereby indirectly aggravating the waterlogging problem in the area. The impact of surface water development on the existing ground water regime therefore needs to be studied for judicious use of surface water and ground water to derive optimal benefits.

The purpose of this study is to present the ground water availability in the Bargi Left Bank Canal (LBC) command area. Ground water recharge has been estimated for pre-Bargi LBC situation i.e. before introduction of extensive irrigation in the canal command area.