WATER resources are becoming increasingly defenceless the world over as a result of intensified demand arising from increasing population, the need for escalated food production, pollution due to various anthropogenic activities, mushrooming industrialisation and the impact of global warming.
In Pakistan, the agriculture sector roughly utilises 95 per cent of all water resources. The share of cultivated area in water utilisation is 80pc in the form of irrigation, which results in 90pc agricultural production in the country. The remaining production originates from rain-fed (barani) lands.
The water resources of Pakistan include surface water, rainfall and groundwater. The scope of availability of these resources is location-specific. Surface water resources of the country are mainly based on the flows of the Indus river and its tributaries.
Rivers in Pakistan have independent flow characteristics. However, all of them generally start to rise in the spring and early summer and the flows are minimum during winters.
The mean annual rainfall distribution in Pakistan has a broad regional variation. It ranges between 125 millimetres in Balochistan (south-east) to 750mm in the country’s north-west. Rainfall is neither sufficient nor regular.
Most of the groundwater resources of Pakistan exist in the Indus Plain, extending from Himalayan foothills to the Arabian Sea, and are stored in alluvial deposits. Water resources of Pakistan are depleting whether it is underground, in streams, rivers, ponds, etc.
The significant issues related to water availability in Pakistan are that there is annual and seasonal variability in the availability of surface water and impact of global warming.
In our region, there is a reduction in the capacity of storage reservoirs due to sedimentation and increase in domestic and industrial use of water.
Karachi is facing extreme water shortage where water is available at around 1,200 feet to operate a tube well. Same is the case with Lahore where the water table level is 800 feet.
Low rainfalls over the years have resulted in low river flows and drought conditions, affecting agricultural crops.
The surface and ground-water quality is degenerating day by day. Besides, the haphazard discharge of industrial and domestic wastewater into open water bodies and groundwater continues unabated.
The absence and non-implementation of legislative measures and standards has been the basic cause of the deterioration in water quality.
The issue is becoming serious as lakes, rivers and streams are being increasingly contaminated by pollution from industrial, agricultural and municipal wastes.
We have three major reservoirs in our country, i.e. Mangla, Tarbela and Chashma, and sedimentation is going to decrease their storage potential in the last few years by 40pc.
In Pakistan, water logging and salinity is another major problem which emanates from poor management of irrigated agriculture, seepage from unlined earthen canals, flat topography, scanty provision of drainage and the use of poor quality drainage.
An extensive social work is required, using the mass media and a village-to-village campaigns of extension services.
Effective extension service operation must be developed to transfer new and efficient irrigation methods, technologies, and practices to farmers.
Efforts should be done to introduce up-to-date methods and cost-effective locally developed technology should be encouraged.
Improved surface irrigation methods should be adopted, for example, in plain areas, where row crops like cotton, wheat and maize, etc, are grown, bed and furrow irrigation methods should be made obligatory for adoption by farmer.
The writers teach at a public sector university in Pakistan
Published in Dawn, The Business and Finance Weekly, September 5th, 2017
