Drainage scavenger tube wells can sustain rural livelihoods: evidence from Sindh Pakistan

Pakistan is an agricultural country. The supply of irrigation water to crops is being made through a network of surface irrigation systems and groundwater. The left Bank of Lower Indus covers administrative boundaries of ten districts which includes districts of Nawabshah and Sanghar. The government of Sindh Province installed more than 350 scavenger (saline and fresh bores together) tubewells in Districts Nawabshah and Sanghar with the main objective of providing drainage and to recover shallow fresh groundwater for irrigation supplements. The study was carried out in a command area of 79 tube wells of District Nawabshah to examine the effect of these tube wells on sustainable rural livelihood of irrigated agriculture community. The continuous pumping from the scavenger tube wells for more than two days indicated that there was not any significant change in water quality, thus it is concluded that the scavenger tube well is a good method to control saltwater movement in to freshwater zone by balancing or keeping interface at constant level provided that the ratio of saline water to freshwater pumping is I:1. Pre-project findings reveal that 91% of irrigated agricultural land had a severe water logging situation and 9% of the area was moderately water logged. The recorded average water table depth was <0.15 m. The cropping intensity was recorded at <30% and the maximum yield of major crops such as cotton, wheat and rice was 1080, 1400 and 1400 kg/acre and the maximum land value was less than Rs. 40000 per acre. The women and children were the most affected because more than 85% of rural women were engaged in agricultural activities. Post project (1999-2007) results indicated that the average water table depth was below 1.5 m depth from the surface. However, the categorical decrease in water table was: 60% area was below 1.75 m depth and 40% area was between 0.75 and 1.5 m depth. The maximum crop yield of major crops such as cotton, wheat and rice was increased to 148%, 55% and 55%, respectively, and the cropping intensity was increased to 149%. The land value of agriculture command area was also increased to more than Rs. 150 000 per acre (274%). Operation and maintenance of tube wells was determined as Rs. 315/acre, which includes charges of electricity, person deployed for operation, maintenance of tube well and disposal channels. Presently, all this cost is borne by the government of Sindh. The influence of reverse seepage of saline water from the disposal channels has been investigated, which indicated that when channels were constructed above ground surface level, then the seepage of saline water affected about 30 m width in each side of the channel area (Kori etal., 2009). It is concluded that the scavenger tube well was a good approach to control water logging, protect salt water intrusion into the freshwater zone, increase cropping intensity and sustain rural livelihood of irrigated agriculture community. Further, if the operation and maintenance is given to the farmer community then it would be unacceptable to the farmer community because its operation and maintenance is beyond the scope of farmer due to cost and technicality. Also, the scavenger tube wells maintain an unchangeable saline-freshwater interface.