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Dam Construction in Pakistan

Thats cool and nice hear about another dam but a 93 months a very long time can we speed it many 969 MW is a good amount this will be multiply by 3 in comming days by making more dams
 
Its an amazing project and would add much to Pakistan. But i m sure its completion date has been enhanced till 2011, wat could be the reasons i think its bad on part of companies working there or some resources problem.
 
My family lives 5 minutes from the dam.......we get a new double road and it knocks about 15 min of the journey..great.
There where loads of chinese people at the start of the project,it was really funny seeing them start with 5 armed guards for every one person,but after a bit of time the chinese got rid of the guards and started mixing with the locals...there really cool people.:china:
 
Basha Dam construction likely to start in 2009

LAHORE: The construction work on Diamer-Basha Dam project will likely commence after the international competitive bidding in 2009.

Draft detailed engineering designs and tender documents of the project have been submitted by consultants and are being reviewed for finalisation.

According to source, the German Company Lemhyer has submitted a detailed engineering design to WAPDA, which is being reviewed by the authority.

Consultant Company has made many recommendations to government including setting up four hydropower stations of 1,150MW for royalty purposes to North West Frontier Province (NWFP) and Northern Areas. The company has informed the authority that 4,500MW electricity would be generated by the dam project.

In the draft of detailed engineering, the company has also recommend to keep flow rate of water at the level to fill the dam in four years and suggested to store 60 percent water in the dam and release 40 percent to generate power and irrigate crops.

The company has also recommended maintaining water outflow of 35,000 cusecs and keeping the height of dam at 1,160 metre instead of 1,170 metres set earlier to store water at the time of sudden melting of glacier.

It has also indicated that 27,000 families would be affected by the construction of dam and recommended setting up nine model villages near Gilgat to accommodate these affected families. The company has also recommended allotting five Marlas for residence per family and six canals to one family for agriculture purpose.

A briefing was given to a delegation of staff course, Naval War College in Lahore at WAPDA House on Saturday and it was told that the work on the construction on Basha Dam would start in 2009.

Pakistan Electric Power Company (PEPCO) Managing Director, Munawar Baseer Ahmed and WAPDA Member (Water) Muhammad Mushtaq Chaudhry briefed the delegation about the power and water scenario in the country.

The delegation was appraised that Pakistan is heading towards a situation of being water deficient country, because per capita water availability has already reduced to an alarming figure of 1,070 cubic metres in the year 2007. It is pertinent to mention that a country, according to the universally accepted parameters, is declared water scarce country if per capita availability of water reduces to 1,000 cubic meters.

The delegation was briefed that the accumulative gross storage capacity of Tarbela, Mangla and Chashma reservoirs that used to be 18.37 million acre feet (MAF) originally, has reduced to 13.22 MAF due to sedimentation, resulting in 28 percent loss of storage capacity. Hence, construction of at least one mega dam is inevitable to meet the growing need of water in the country. It was told that another 20 million acres of virgin land could be brought under irrigation if additional water is made available by constructing new water reservoirs in Pakistan.

It was told that the filling of water in the raised Mangla Dam would start this year. The first phase of Greater Thal, and Kachhi canals are expected to be completed by December 2008, while the first phase of Rainee Canal Project is likely to be completed in March 2009. It was further told that the engineering studies of 15 hydropower projects with accumulative generation capacity of 25,270MW are being carried out by WAPDA.

The delegation was informed that PEPCO is striving hard to minimise the gap between consumption and generation of electricity by adopting various short, medium and long-term measures. A number of reforms are being introduced to make power sector of Pakistan more efficient and customer friendly, it was added.
 
Diamer-Basha Dam: engineering design, tender documents of project completed

LAHORE (July 01 2008): Water and Power Development Authority (Wapda) Chairman Shakeel Durrani has said that the detailed engineering design and tender documents of the multi-purpose Diamer-Basha Dam project had been completed, while all the studies and details had also been reviewed by the international panel of experts.

He was speaking after the presentation by the consultants of the dam at the Wapda House here on Monday. Durrani further said that Rs 200 million had been allocated for the detail design of the project in the 2008-09 Federal budget, while the pre-qualification process of the contractors had already been initiated.

He further said that Diamer-Basha Dam was a 8.50 billion-dollar project, having immense importance, as it was the largest project ever executed in any sector in the country. He stated that the construction of the project would commence next year following international competitive bidding and every effort would be made to ensure that the highest professional standard of quality and safety were maintained.

The project would go a long way to cope with the increasing demand of water and electric power in the country, he said, adding it would help increase the ratio of low-cost hydel power in the national grid. Diamer-Basha dam will be the highest roller compacted concrete (RCC) dam in the world with more than 100-kilometre long reservoir and 272-metre in height.

Its storage capacity would be 6.4 MAF, while 4,500 MW of electricity will be generated by the project. Diamer-Basha Dam will contribute more than 18,000 Giga watt-hours of electricity annually to the national grid. Earlier, the consultants of the dam briefed the Wapda chairman, besides officers of Water and Power Ministry and Planning Commission, former members (Water) and members of the authority.

Business Recorder [Pakistan's First Financial Daily]
 
PROJECT BENEFITS

• Availability of about 6.4 MAF annual surface face water storage for supplementing irrigation supplies during low flow periods
• Harnessing of renewable source of clean and cheap energy through installed capacity of 4500 MW
• Reduction of dependence on thermal power, thus saving foreign exchange
• Employment opportunity, particularly to the locals, during the construction and operation
• Creation of massive infrastructure leading to overall socio-economic uplift of the area and standard of living of people.

ENVIRONMENT AND RESETTLEMENT*

(After Reducing Dam Height by 10m)

• No. of villages affected 30
• No. of Houses Affected 2200
• Population affected 22,000

• Agricultural land submerged 1,500 acres
• Area under reservoir 25,000 acres
• Length of KKH submerged 100 km
• Proposed new settlements 9
• Infrastructure Electricity, roads,
water supply,
schools, health
centres etc.

*Subject to refinement during detailed design stage


SALIENT FEATURES

• LOCATION 40 km downstream of Chilas

• MAIN DAM
Maximum Height 270 m
Type Roller Compacted Concrete (RCC)

• DIVERSION SYSTEM 2 No. Diversion tunnels
1 No. Diversion canal
Upstream and Downstream Cofferdams

• MAIN SPILLWAY No. of gates 9
Size of gate 16.5 Χ 15.0 m

• RESERVOIR LEVEL 1160 m
Gross capacity 7.3 MAF
Live capacity 6.4 MAF
Min. operation level El. 1060 m

• OUTLETS
Intermediate level 8
Low level 4

• POWERHOUSE(S) 2
Total installed capacity 4500 MW
Location and type Toe of the Dam (one each on the right and left side)
No. of units 8, each of 560 MW
Average generation 16,500 Gwh/year

• ESTIMATED COST (YEAR 2005)
US$6.5 Billion​
 
Neo.
Thanks for the detailed info. it is always difficult to assess the usefulness of a project like this. One of the things in favour of Kalabagh is the useful life of the project. Do we know what the useful life of this project will be?
Secondly-- We have heard of the problem of silting of dams. My question is whether it is possible to dredge the silt away. If it, why is it not considered? What resources would be required for it?
Thanks in advance for your help in this regards
waSalam
Araz
 
Neo.
Thanks for the detailed info. it is always difficult to assess the usefulness of a project like this. One of the things in favour of Kalabagh is the useful life of the project. Do we know what the useful life of this project will be?
Secondly-- We have heard of the problem of silting of dams. My question is whether it is possible to dredge the silt away. If it, why is it not considered? What resources would be required for it?
Thanks in advance for your help in this regards
waSalam
Araz

Dredging any thing below 30 meters is either not cost effective or useless. I guess they will have silt gates at the bottom for that.

Regards
 
Neo.
Thanks for the detailed info. it is always difficult to assess the usefulness of a project like this.
You're welcome Sir!

One of the things in favour of Kalabagh is the useful life of the project. Do we know what the useful life of this project will be?
Dams of this magnitude usually serve 40-50 years but lifespan can surely be expanded as new technologies come available.
Diamer-Basha Dam will also serve as one of four mega water reservoirs designed to reduce flooding in moonsoon and to add water into Indus and other rivers in dry season.

Secondly-- We have heard of the problem of silting of dams. My question is whether it is possible to dredge the silt away. If it, why is it not considered? What resources would be required for it?
Thanks in advance for your help in this regards
waSalam
Araz

Japan and Italy have developped new metheods and technology to avoid damage from slit, debris and sediment discharge. I'll try to find some useful info on their studies.
 
DESIGN OF SLIT DAMS FOR CONTROLLING STONY DEBRIS FLOWS

Hui-Pang LIEN

ABSTRACT
A new method to a slit dam for controlling the stony debris flow has been derived based on the mass conservation law of the stony debris flow passing through a slit dam and the laboratory experiment results. This new method is then combined with three primary efficiency expressions: the dimensionless sediment outflow ratio, the sediment concentration ratio, and the sediment storage rate to develop a simple module, with which the height and the spacing of the posts, as well as the total spacing of slit dam are determined.Furthermore, these expressions can also be applied to check those slit dams that have already beenconstructed with their effectiveness against various magnitudes of the debris flow. The comparisonbetween these expressions and laboratory data is in reasonable agreement.

Key Words: Stony debris flow, Slit dam, Dimensionless sediment outflow ratio, Sediment concentration ratio, Sediment storage rate

INTRODUCTION
Stony debris flows are natural, highly concentrated water-sediment mixture, which forms wherever thesimultaneous availability of water, debris material and an adequate slope, steeper thanare satisfied(Gregoretti, 2000). In mountainous regions of Taiwan, due to vast development and utilization of hills, stony debris flows are important from the point of disaster prevention, since they occur frequently and oftenbring about heavy loss of lives and properties. Therefore, much research on stony debris flowscountermeasures has been conducted for the past fifteen years.

Current countermeasures to cope with such disasters are either structural or non-structural in nature. The most commonly used structural method is toconstruct check dams, levees and channels to catch all the sediment transported by stony debris flows.Ordinary check dams (See Fig. 1) are closed-type and made of massive concrete. Check dams, which areoften constructed in series, have been widely used in Taiwan, Japan and Europe to reduce the debris flowdisasters. However, due to the nature of their narrow storage space and poor permeability, check dams arefilled with sediment by small discharge before debris flow occurs.

Check dams have failed to catch the debris flow efficiently. To make up for this disadvantage, open-type dams have been developed in countries such as Austria, Japan, and Taiwan (Watanabe,1980; Fiebiger, 1997; Lin and Lin, 1999; Heumader, 2000).Open-type dams, designed to block and trap debris, come with many different styles and shapes, e.g. slit dams, dams with a rectangular slit, grid dams, bottom screen dams, etc. They all share one major function that the close-type dams lack: they allow sediments that do not cause any harm to thedownstream areas to pass down the channel while retaining destructive larger boulders. As such they are preferable over conventional check dams for conserving as much as possible the natural environment and the landscape of mountain ********. o10The effectiveness of the slit dams in the prevention of debris flows has been proven in several studies conducted in Japan. These studies all reach the conclusion that changing the spacing of the posts could decrease the debris flow peak discharge and allow the non-harmful sediment to pass through freely whilecatching the harmful sediment downstream. Watanabe, et al. (1980) has shown that the spacing of the postshas effects on the trapping capacity of a slit dam.


Read the full article here: Design Model of Slit Dam for Debris Flow Control
 

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