Moving towards water famine

Per capita availability of water in Pakistan has gone down to only 1,070 cubic meters, from around 5,000 cubic meters in 1949-50, while the country has lost water storage capacity equivalent to 5.13 MAF to silting at Tarbela, Mangla and Chashma, says a Recorder Report quoting a high Wapda official.
This indeed portrays a serious situation that will have a long-term impact on our hydropower generation potential as well. The high rate of sedimentation in the country's reservoirs is a problem that has badly affected long-term sustainability of agriculture in the country.
High sedimentation load both in water reservoirs and the irrigation system acts as a major constraint, which is second only to waterlogging and salinity. The storage capacity of water reservoirs in the country has gone down from 16 MAF to 13 MAF, and experts believe that Pakistan is losing around one MAF of water every four years, which is a very high ratio indeed, for a water-stressed country like Pakistan.
Therefore, initiating proper water conservation and management practices, particularly in the catchment areas is of critical importance, as this can yield a very high payoff through a significant reduction in sedimentation flow into the rivers.
This will also contribute to agricultural production and environmental improvement through reduction in silting of irrigation channels, and improved fishing catches, as water quality improves with decrease in siltation, and reduced flood damage, which in turn helps reduce environmental damage.
According to a leading expert, the long-term sustainable average annual net inflow of the Indus Basin is 175 billion m3, while canal diversions over the same period have averaged 128 billion m3, with an average of 35 billion m3 flowing down the Kotri Barrage into the sea.
This provides a measure of the huge loss the country has sustained because of its inadequate water storage capacity. Similarly, the average groundwater availability stands at 63 billion m3 while the use of groundwater for irrigation and for urban and rural drinking water supplies has been estimated at about 52 billion m3.
Other evidence, such as increased salinity of groundwater due to redistribution of salts in the aquifer and declining water levels, suggests that there is little, if any, further potential for groundwater exploitation. According to this analyst, the bottom line is clear - Pakistan is overusing its available surface and groundwater.
It is projected that over 30 percent more water will be needed over the next 20 years to meet the country's increased agricultural, domestic, and industrial demands. There is an urgent need of greater use of water conservation techniques, modern water management methodologies and enhanced water storage capacity. However, on all three fronts our water bureaucracy's performance has been extremely disappointing.
There has been considerable loss of water due to inefficient irrigation application at the field level. Because of poor surface irrigation hydraulics and unlevelled fields, farmers apply enough water to cover the highest spot in the field.
The result is not only excessive non-beneficial use of water, but also loss of nutrients, especially nitrates, and pollution of the groundwater with these excess applications of agricultural chemicals. Secondly, there has been waste of water due to weeds, shrubs, and the plants that grow along waterways, weeds in fallow fields, and vegetation in wastelands.
As the weed infestation is very high in the Indus Basin, almost 20 to 30 percent of water is consumed by weeds. Thirdly, watercourses are the main source of weed seeds to the fields. Weeds grown along the watercourses shed seeds, which ultimately reach the fields through the irrigation water. Therefore, weeds in cropped fields not only reduce the crop yield, they also consume water which could have been used to secure higher crop yield.
A Planning Commission study has warned that Pakistan will have to enhance its per hectare farm yield if it wants to avoid being caught in a serious food crisis. The incremental shortfall in the quantum of Pakistan's food production, coupled with a rapidly increasing population which at present stands at over 160 million, is threatening the country's food security.
For instance, it has calculated that wheat production alone will have to be increased to 25.4 million tons by the year 2015 and to over 33 million tons by 2030 to meet the country's requirements. The question is: will the government be able to meet these targets with its leisurely pace of water project implementation? Under Wapda's Vision 2025 programme, we have to construct storage capacity of 65 MAF.
Obviously, things must be speeded up. As much as 30 MAF of water flows down into the sea unutilised each year, which can be put to productive use through construction of additional dams and reservoirs. Secondly, the government should launch a countrywide awareness campaign to educate the growers about water conservation and management techniques, to ensure optimum use of this precious resource.
Thirdly, it should undertake de-silting of all major reservoirs to increase their capacity. Fourthly, it should expedite construction of dams and water reservoirs in the country.