Dams, Why Not to Damn!!
For a country blessed with many rivers, the unpleasant home truth is that there is impending scarcity of water in Pakistan because of acute shortage of storage capacity. This will become further acute in the near future, a full blown crisis not so far in the distant future. The looming disaster can be overcome in several ways, not the least being, viz (1) conserving the water we have and maximizing its effect (2) eliminating, or at least minimizing wastage and (3) apportioning it judiciously on a need-to-have basis. While there are notwithstanding alternate sources of generating electricity, power from water sources is far cheaper.
To cater for the loss of the exclusive use of the waters of the eastern rivers Ravi, Sutlej and Beas to India, because of the 1960 Indus Water Treaty, Pakistan went for a number of dams, barrages and link canals in the three western ones, Indus, Jehlum and Chenab meant for its exclusive use. With the help of the World Bank (WB) in the 60s and 70s, mega projects such as Mangla Dam and Tarbela Dam meant both for irrigation and cheap electricity were set up. With increasing requirement for both water and power, two additional dams are needed between now and 2015.
Estimates of existing shortage of water range from 9-12 MAF based on estimated water requirement of 115-116 MAF at farm gate. The existing water 105-106 MAF available at farm gate is calculated as viz (1) surface 61-62 MAF (2) and 43-44 MAF underground water from irrigation system, about 40-42 MAF being lost through evaporation/seepage. The annual average flow of water downstream of Kotri Barrage into the sea is estimated at 35 MAF.
Only 44 of the 77 million acres suitable for cultivation in Pakistan are presently being irrigated, including Barani areas the total under cultivation jumps to 54.5 million acres. Another about 22 million acres can be brought under cultivation. If the irrigation channels are lined and with improved agriculture practices, another 15-20 MAF would be needed by 2020. The additional storage capacity required will be 20 – 25 MAF or 4 – 5 large dams. Pakistan existing storage capacity is only 10%, the world average is 40% of average annual river flows. Tarbela, Mangla and Chashma dams with 15 MAF represents 90% of the storage capacity. Silting will lose these dams 6 MAF by 2010, equivalent to one mega Dam.
Water escapage from Kotri can be quite substantial, ranging from a low of 8 MAF to as high as 92 MAF. With surpluses in the river system available only for a period of 70-100 days, storage is essential, to be used judiciously for agriculture, hydropower generation, flood control, etc. Storage has to be large enough for inter-season (Kharif Rabi) transfer and inter-year transfer from wet to dry years. The planned multi-purpose dams of Bhasha and Kalabagh on the Indus are complementary and give us about 10-12 MAF, the minimum requirement. Sindh would get additional assured supply of 2.2 MAF because of Kalabagh, the water supply at GM Barrage improving for canal water available during all seasons. This will augment Bhasha Dam construction by another 2.2 MAF, water increasing at Guddu Barrage. Supply will also increase from Mangla Dam to Sindh during early Kharif season (March-April). Flow of water below Kotri, estimated presently during Moonsoon season (at 8-10 MAF), will be better regulated throughout the year.
Nearest to the power load center and transmission network, Kalabagh, with a catchment of 90 MAF, is ready for implementation and can be completed in 6-7 years in 2012 it will enhance Tarbela generation by 30% by installation of three additional units. 200 kms upstream of Tarbela and outside the monsoon range, Bhasha Dam has a catchment area of 50 MAF yearly. Non-perennial canals of Sindh and Balochistan receiving perennial supplies, large tracts of Barani lands will receive irrigation water from new canals. Bhasha drawback is that it needs sustained upgrading of 110 kms of Karakoram Highway (KKH) over a period of 4-6 years, with remedial work on about 300 kms supporting roads.
The facts about Kalabagh are contrary to apprehensions voiced, viz (1) how can Peshawar valley fear flooding, particularly Nowshera Town with breakwater of Kalabagh lake 10 miles downstream? (2) with lowest ground level above 170 feet and the conservation level of Kalabagh at 915 feet, water logging and salinity of Mardan, Pabbi and Swabi plains is not possible (3) with Mardan’s SCARP operations, far above Kalabagh levels how can it be affected? (4) with the lake extending 92 miles up from Indus River and 36 miles up from Soan River, maximum cultivable land submerged will be 30000 acres (24500 acres in Punjab) (4) population dislocation will be about 1 lakh with 65% from Punjab and only 35% from NWFP (5) resettlement of dislocated process will be done in model villages.
Among Sindh’s concerns are escapages below Kotri. Reviewing three studies done by independent consultants’ consortium, a WB-appointed “Panel of Experts” recommended that viz, (1) at least 3.6 MAF escapage per year to check seawater intrusion, fishing and environmental sustainability, and maintenance of the river channel. The caveat is that 25 MAF be released in concentrated form as flood flow every 5 years (Kharif season) for maintaining mangrove vegetation and preserving river morphology in the Indus delta. The more emotional response from Sindh needs to be assuaged, viz (1) the feeling there is no surplus water but Kalabagh Dam can be filled by only 6 MAF, and during July to September about 35 MAF will be available, (2) Sindh fears desertification but dams only accumulate water during floods and water will be available during dry periods; canal withdrawals actually increasing to 2 MAF (3) with no plan in the design for high level outlets apprehension about these being used to divert water from dams with NWFP drawing water in excess of its requirements is wrong. Even if the two canals were included in the project they would draw according to a telemetry system as per the 1991 Water Accord (4) Fears that cultivation in riverain (Salaiba) areas would be adversely affected are also incorrect, additional water would be available for tube wells (5) fears about seawater intrusion in Indus estuary increasing are also wrong, studies show it is already at the maximum now without fear of further aggravation, (6) fear about seawater intrusion seriously affect existing aquifer system is wrong, freshwater gradient being southwards to lower part of Delta, it cannot effect the existing system (7) with mangrove forests comprising only 0.32 MA of the totally inundated Indus Delta (about 1.53 MA), fears that these may be endangered are wrong. Mangrove forests cover only 7400 acres, 95% of the plants are in 0.32 MA and are salt tolerant spices (8) fisheries stock has never declined due to progressive reduction of surface water supplies.
How do we overcome the deep-rooted apprehensions of Sindh about diversion of water from Kalabagh by Punjab? What credible constitutional guarantees can be put in place to assuage their fears? Can a cast-iron mechanism satisfy Sindh? Can the provinces share the additional water as well as the revenues from the cheap electricity guaranteed? The President is on a fail-safe line with respect to the political fallout versus the over-riding national interest. Will he risk his place in history (and in the country) by taking decisions which may be unpopular, at least in one Province? The decision must be in the supreme interest of the country. One believes the President will take the calculated risk to go with both Kalabagh and Bhasha, with adequate design changes and cast-iron guarantees to cater for the fears of Sindh.
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