ISLAMABAD          -          A potentially dangerous silt delta is mere four kilometres away from touching the main structure of Tarbela Dam and is a constant threat to choke down the reservoir. The Senate Standing Committee on Water Resources that met under Senator Syed Muhammad Sabir Shah discussed in detail sedimentation at Tarbela Dam and measures taken to address it; plot allocation to affectees of Tarbela Dam and encroachment of the same. During briefing on the issue of silting at Tarbela Dam, the committee was informed that a delta is moving towards the main structure of the reservoir which at present is 04km away from the reservoirs and moves with a speed of 0.25 mile/annum. The delta is huge mountain of sand, mud and gravel which is moving towards the dam tunnels and it is only 4km from the dam, the official informed. The delta has the potential to hit the structure of the dam and is a constant threat to choke down the reservoir. In its previous meeting the committee was also cautioned that a sudden earthquake can also increase the potential danger of clogging due to liquefaction of bottom set and fore set slopes would increase as the delta moves closer to the dam. The committee was apprised that the percentage loss in gross and live storage capacity of Tarbela Dam is 43pc and 39pc respectively. The committee was further briefed that the option of de-silting of Tarbela reservoir has been considered and its pros and cons have been evaluated that de-silting of Tarbela reservoir will choke the entire irrigations system. In Tarbela Dam, 200 million Tons of silt is being accumulating annually and 10 billion tones of silt has been accumulated in the reservoir so far, WAPDA official informed. A survey is conducted every year and the process siltation is reviewed, WAPDA official said. Siltation is increasing at the rate of 0.24 per cent per annum, the official said. In 1974, the sand delta was 14 miles away when it was first surveyed, WAPDA official said. A huge amount of dollars is needed to remove the delta from the dam, officials said Eight studies have been done for desiltation of Tarbela Dam, official said. The committee was informed that in compliance with the discussion carried out during last meeting, WAPDA identified two renowned experts in the field of sedimentation of reservoirs Dr Gerrit Bassom (South Africa) and Dr Gregory Morris (USA) for further studies. All the eight experts advised/proposed raising of intakes to avoid clogging/blockage due to sediment movement, therefore, further studies will not be considered beneficial with respect “to any suggestion as all the low level outlets have been raised/raising in progress with the assistance of World Bank. The meeting was informed that further study will involve expenditure in foreign currency as well as time of three to four months and the results may likely be same, because Tarbela Dam is in operation and further modification will not be advisable after passing 50 years useful life of many of the structure. The meeting was informed that for sediment management two upstream reservoirs, Dasu and Basha are under construction which will result in less inflow of sediments in Tarbela Reservoir after completion. South African and American experts have estimated a huge cost for the de- siltation of Tarbela, WAPDA official said, “The first eight studies have been done and in the light of this the work we are doing is sufficient, WAPDA official informed. Discussing sedimentation at Tarbela Dam and measures taken to address it, members of the committee were of the view that while looking at ways to de-silting the dam, measures must be taken to allow sediment flow to a certain degree, since this ensures land fertility. The ministry was directed to formulate a report that would outline long and short term measures to deal with the issue. The committee questioned WAPDA that what steps are being taken to stop silting sedimentation in Bhasha Dam. The committee has called for a briefing on Bhasha Dam in the upcoming meeting. Let make it sure of not making the same mistakes as Tarbela Dam in Bhasha Dam, the committee remarked. The Ministry of Water Resources also complained about less funding to water resources projects in the PSDP. One trillion projects have been delayed for years due to lack of funding, the water resources official said With the existing PSDP funding, development projects can be completed in 15 to 20 years, the official insisted. Reviewing details of plot allocation to affectees of Tarbela Dam Commission, the committee was informed that the number of affectees that have been compensated is 1744. Some 450 affectees filed writ petitions before Peshawar High Court Abbottabad Bench for allotment of alternate agricultural land and enhancement of compensation against WAPDA, federal government, governments of Punjab and Sindh. Based on information provided by 450 affectees, only one affectee was found eligible with respect to allotment of alternate agricultural land as per eligibility criteria of the federal government policy of 1967- 68. Since the case is in court and is subjudice, the committee stressed the need for the perspective of both parties emphasising an out of court settlement. Discussing unauthorised occupancy of allotted land to affectees of Tarbela Dam in Punjab and Sindh, WAPDA was of the view that no such information regarding this issue was available with it as it is the domain of the provincial governments. Moreover it was suggested that if the Committee comes across any such case it may forward the same to the Ministry of Water Resources.