Small Dams and Restoring life line in Pakistan
By SYED MUJAHID ALI SHAH
Pakistan is a nation likely to struck with historical floods in the wake of climate change in the coming years, paralysing its single most important source of employment and base of export-agriculture which caters above 170 million people giving livelihood to 66% of national population employing 43.4% of work force is facing a historical economic crisis, Agriculture in Pakistan generates 20.9% of the state’s GDP mostly coming from agricultural land, irrigated with Indus Basin River System (IBRS). The sector under devastation, being strongly linked with food security, poverty alleviation, and rural development is going to generate multiplier effects. In all cultivated area of 19.63 million hectares, IBRS irrigates total agricultural land of18.22 million hectors which is above 90 percent of the total and makes the irrigation system of the country, the largest in the world.
The new born nation in the holy month of Ramadan, on August 14, 1947, initiated its life line project of Indus Basin Replacement Works Project (IBRWP) with the help of World Bank; initially the system irrigated 39.54 million acres. Now as IRBS it has been irrigating nearly 20 million hectors consisting the Indus River and its major tributaries of Ravi, Chenab, Sutluj, Jehlum and Kabul which pass through three major reservoirs of Mangla ( constructed in 1967), Chashma ( constructed in 1971) and Tarbela (constructed in 1975).There have been 19 barrages, 12 link canals, 43 canal commands, and over 107,000 watercourses. The length of canals of the sysetm in total makes 61,000 km with watercourses, farm channels, and field ditches which stretches another 1.6 million km. Typical watercourse commands range from 200 to 700 acres.
The hugest volume of water so far recorded in the history of Pakistan ,developed from monsoon rains in the northern higher mount belts in Khyber Pakhtunkhaw and Kashmir has totally devastated IBRS the nations life line by inundating it with floods going 40-50 Km wide and flowing with more than a million cusecs of water.
Although IRBS is fed with more than 90 percent of total flowing water by Upper Indus Basin comprising a high mountain formation of Himalayas, Karakoram, Hindukush and Pamir ranges containing the greatest area of 22,000 km2 perennial glacial ice outside the polar regions in the world recently named as Third Pole; in Gilgit Baltistan, Chitral and Kashmir regions ,but monsoon rains contribute much for Rabi crops in early summers when glaciers thaw is still slow and melt five times less than that of Kharif season. Monsoons are also becoming more important from a futuristic point of keeping the fast melting glaciers scenario in mind. Studies have shown that land surface temperatures have risen more than sea surface temperatures and that temperatures in higher elevations are rising more rapidly which means increase in monsoon as due to change in seasonal cycle but recession of glaciers most of which are out of monsoon range being on the northern face of Himalayas.
But containing the monsoon water for Kharif crops necessitate reservoirs. Especially when the weather is becoming historically unpredictable year to year thanks to climate change. The flooding as that of present are not only a loss of water in bulk but also create devastation out of ones imagination. To avoid the situation major dams and reservoires are necessary to be built.
Diamer-Bhasha Dam with a capacity of 8,107,132 acre·ft water reservation 4,500 megawatts
Similarly the major reservoir project of Kalabagh Dam in the monsoon zone is also necessary but under political manoeuvring so far since it was planned in 1984, mainly opposed by Khyber Pukhtunkhaw province.The dam can contain a big part of rain water having a reserving capacity of 8 million acre feet (MAF) coming from the northern hights , Khaybar Pakhtunkhaw of which 6 MAF can be used for agriculture.
The government should impose emergency and start constructing small catchments and medium sized dams on Indus River in Gilgit Baltistan and KPK region which can help containing heavy rainfall and save the downstream areas from inundating .They can also be used for irrigation and power generation. Such projects are relatively less time taking, can solve power generation crisis within limited time, low costly and less destructive in case of failure.
Syed Mujahid Ali Shah is a nature conservationist/ecologist, freelance writer, researcher and teacher based in Nagar.
