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Today's Paper | December 23, 2024

Published 14 Apr, 2003 12:00am

Mirani Dam project

The Mirani Dam, a resource project to manage sustained supply of water for development of agriculture and for daily use of the population in the Makran Division of Balochistan, is being constructed across river Dasht at the confluence of Kech and Nihang rivers, 30 miles west of Turbat city.

Being implemented by Wapda, this project is located 380 miles north-east of the provincial capital Quetta. Having central Makran range in the north, the eastern and western sides of the dam project are not demarcated by any natural features.

The dam forms a part of Wapda’s ‘National Water Resource and Hydropower Development Programme’: Vision 2025”. On completion,the project will provide irrigation water for the lands on both sides of the non-perennial river Dasht, which is mostly dependent on rains in the upper catchments area, averaging 4.2 inches per annum.

The catchments area is punctuated by 7,960 square miles of barren mountains. Water inflows from the catchments are around 226,000 acre feet, estimated to bring with silt-flows of 7,000 acre feet per annum.

The studies were conducted to develop a sustainable water storage of 114,000 acre feet capacity by building a 244 - 266 feet above the mean sea level high dam.

In view of the availability of water, the crest level of water storage was assessed 256 feet above mean sea level, but in this case considerable acreage of the invaluable agriculture lands, orchards and residential areas of the local population would have merged in the water reservoir. In case of implementing this proposition, not only a handsome amount for rehabilitation compensation package was required but also the arrangements for resettling displaced population numbering 5,000 were essential.

Therefore, the option of 244 feet water storage level was studied. As per the conclusions of the studies, instead of 256 feet, going for 244 feet high water storage level of the dam was analyzed which would affect only 43 per cent of the existing orchards and residential lands of the area whereas the decrease in water storage for irrigation supplies would be only 10 per cent. With 244 feet high dam, only 1,100 persons will have to be shifted from the areas to be affected by the water storage.

Having the studies made and the possibilities analyzed, the feasible height of the dam water reservoir was decided at 244 feet above mean sea level as this height would trace minimal of environmental and social effects and the affected population could be provided maximum facilities within the very reasonable financial impact.

The completion of the project would help, raising annual average production of the existing orchards, vegetables, fodder and wheat crops by 85 per cent. This increase is expected by 36 per cent in Kharif and 49 per cent in Rabi crops while in the period of maximum availability of water 122 per cent raise in the cropping intensity would be possible. The irrigation system has been so planned that it meets the requirements of 122 per cent cropping intensity target.

As a result of the dam, collective produce of the crops is expected to increase manifold from 5,279 tons to 222,657 tons including 5,286 tons of water melon, 48,365 tons of vegetables, 101,640 tons of fodder, 2,633 tons of wheat and 19,714 tons of fruit. The best and economical source of proteins for the local population is molasses, produce of which would increase from 125 tons to 249 tons.

The increased produce of “luson” fodder is expected to attain 31,872 tons mark. The areas which would be brought under re-cultivation would give 1,800 tons of water melon and 12,000 tons of fodder produce per annum during the Kharif season.

During the periods of April to July and September to December when the reservoir would go down from the normal level, cultivation of another 3,000 acres of land would be possible to harvest water melon on 300 acres area during the summer and fodder on 1,200 acres during the Kharif season. Additionally “berseem” fodder in between the crop seasons and in the orchards would also be possible.

As per the surveys carried out, in view of the various beneficial aspects of this water reservoir, the inhabitants of the adjoining areas are in favour of construction of the dam provided they are given adequate compensation. Some of the land owners whose lands are situated close to the proposed dam would have direct gains of the project.

The work for supply of drinking water, sewerage and electricity supply facilities for the workers’ colony have been completed at the site departmentally. Construction of 40 kms long metalled access road from Turbat to the project site and O&M colony has been undertaken.

Land for the dam, measuring 7,668 acres, has been acquired and acquisition of 457 acres of land for the irrigation system is in progress. The Balochistan government was provided an amount of Rs140 million for land acquisition, of which Rs7.91 million has already been paid as compensation to the land owners. Construction of the main dam and spill-way would start within this month.

The federal government has so far contributed Rs1.20 billion for implementation of the project and it is note-worthy that the dam project has no component of foreign investment.

The consultancy agreement for the project was signed with Messrs NESPAK as the head of a joint venture at a cost of Rs112 million on February 11, 2002. Expression of participation were called from the reputed and experienced international construction firms during September 2001.

The consultants, Messrs NESPAK Joint Venture evaluated technical and financial soundness of the six bids received from international companies, and presented its recommendations to Wapda’s Central Contract Cell.In the light of the recommendations of the consultants and the Wapda’ CCC, the contract was awarded to the lowest bidder, Messrs DESCON who quoted the contract price of Rs4.70 billion and the contract agreement was signed with them on June 15, 2002 which paved the way for starting construction work.

There would be no adverse impacts on the local population due to construction of the water reservoir. During April to July and September to December months every year when the water reservoir level would draw down from its 244 feet height to 235 feet level, 3,000 acres additional fertile land will be available for cultivation of water melon and fodder. For this purpose, priority would be given to the cultivators whose land will sub-merge under the water reservoir. Construction of the dam would provide employment opportunities to 200-250 families.

The dam would go a long way in accruing the benefits of raise in living standard of the local population. The unskilled population will have vast opportunities of employment during the construction as well as in the post construction periods of the project.

The business activity will increase. The water reservoir will also be used for fisheries, which would provide the opportunities of additional income, besides proteins to the local population.

Aforestation and plantation around the Mirani dam reservoir has also been planned which would not only minimize evaporation from the reservoir but help arrest the effects of dust-storms and tornadoes also. The trees would facilitate the clean environment, to cater from pollution and to control the temperature.

The project envisages 127 feet high and 3,350 feet long earth and rock filled dam with 10 miles long water reservoir behind the dam having 302,000 acre feet of gross storage and 152,000 acre feet of life storage capacity.Water releases from the reservoir will be managed through 1,490 feet long and of 8 feet diameter round tunnels.

The distribution of water for irrigation purposes will be regulated from the external structure divided into two parts to provide water to the canals off-taking from the right and left sides. Their water releases capacity will be 141 cusecs and 236 cusecs respectively.

The irrigation system of the Mirani dam project will provide water supplies to 33,200 acres of land which involves 12,400 acres on the left bank and 20,800 acres on the right bank.

Collective length of the canals, distributaries and minors of the irrigation system under the project will be 82 miles whereas the total length of water courses will be 328 miles. Thirty percent length of each water course will be lined and the remaining unlined. The irrigation system will comprise 24 head regulators, bridges for seven roads to the adjacent villages, 4 flood embankments, 4 big water channels and 13 underground water channels through the embankments.

Much of the adjoining area of the Mirani dam project is backward having negligible basic facilities of drinking water, health, education, electricity and communication. The project will be of immense benefit to the larger segment of the local population. Improved irrigation system under the project will go a long way in provision of better facilities like education, health and telecommunication for the people of the area.

The environment-friendly project of Mirani dam will have no negative effects. Only 1,100 persons will have to be shifted to the alternate place and only 4,800 acres of the flood affected area will submerge due to the project construction.

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