Dams & Civil Structures

Iraq awards contract for repairing Mosul Dam

Iraq has awarded an Italian company a contract to overhaul and maintain Mosul Dam.

Government spokesman Saad al-Hadithi told The Associated Press that Iraq’s Cabinet awarded the contract to Italy’s Trevi group in early February. He had no precise figure for the contract’s value. However, a Cabinet official said it was worth US$230 million and that work on the dam was to begin before the end of February.

The official spoke on condition of anonymity because he was not authorized to speak to the media.

News of the contract came just days after U.S. Army Lt. Gen. Sean MacFarland, commanding general of Combined Joint Task Force – Operation Inherent Resolve in Iraq, warned of the dam’s potential collapse, saying if the dam fails it would cause mass flooding.

Built in the early 1980s, the dam is made largely of earth and situated on soft mineral foundations, which are easily dissolved by water. A report in 2006 by the U.S. Army Corps of Engineers called it “the most dangerous dam in the world” because of its propensity to erode.

Since the summer of 2014, Iraqi maintenance teams have at times struggled to gain access to the dam, which is north of Mosul. Islamic State fighters seized the dam in July 2014, but Iraqi and Kurdish forces, with coalition air support, took it back within weeks.

U.S. engineers will be in charge of inspecting the work of the Italian company.

Earthquake hits Malaysia near 165 MW Sultan Mahmud facility

Published reports indicate the 165 MW Sultan Mahmud facility, located on the Kenyir River in the district of Hulu Terengganu, Malaysia, suffered no damage after a 2.7 magnitude earthquake was recorded 10 km below the surface of its catchment at 9:25 p.m. on Feb. 23.

Station General Manager Mustafa Hashim reportedly said the physical structure of the dam, called Kenyir Dam, remained intact based on a preliminary inspection almost immediately after the seismic event.

“We will conduct a thorough inspection later today [Feb. 24] to make sure the dam and other structures are safe,” Hashim said.

The Sultan Mahmud project is on Peninsular Malaysia in Southeast Asia, which is south of its boarder with Thailand at the eastern portion of the South China Sea.

Kenyir Dam, Peninsular Malaysia’s largest rock-fill dam, is underlain by granite and is 155 m high with a crest length of 800 m, and the dam fill volume is 15.20 million cubic meters. Crest elevation is 155 m above sea level (ASL) while maximum flood level is 153 m. The maximum operating level is 145 m and a minimum of 120 m. The reservoir surface area at 145 m ASL is 370 km², and has a catchment area of 2,600 km². Storage capacity is 13,600 million cubic metres.

Construction was completed in 1985.

Published studies suggest that construction of the dam and impoundment Kenyir Lake, located in a previously aseismic area, was responsible for several earthquakes in the region from 1984 to 1987.

During the construction phase, the Malaysian Meteorological Department (MMD) recorded 28 earthquakes that had magnitudes of 2.5 to 4.6, and the tremors were felt at a distance of more than 50 km.

Kenyir Lake has a surface area of more than 2,600 km2.

Indonesia dam construction tenders worth US$646 million

Indonesia’s Ministry of Public Works and Housing said the government of Indonesia is trying to complete the tender process by June 2016 for eight dams. The construction tenders combined are worth about US$646 million.

The eight dam projects are planned for the following locations:

  • Sumatra – Rukoh ($42 million) and Sukoharjo ($74 million);
  • Sulawesi – Kuwil Kawangkoan ($78 million) and Ladongi ($50 million); and
  • Java – Ciawi ($89 million), Sukamahi ($69 million), Leuwikeris ($84 million) and Cipanas ($160 million).

The construction tenders are open to private investors. However, Taufik Widjoyono, Ministry of Public Works and Public Housing secretary general, reportedly said if a state-owned enterprise wins any tender, the organization will need to partner with a private contractor for construction of the dam.

Published reports indicate the central government would like to tender a new dam project every two weeks, ending in June 2016. Imam Santoso, Public Works Ministry director of dams, said the ministry tendered Kuwil Kawangkoan Dam during the first week of February and will tender Leuwikeris Dam before March.

Santoso also reportedly said 49 dam construction projects, considered nationally strategic by the Indonesian government, are targeted for completion by 2019. Of this total, 16 dam projects were tendered in 2014 and are currently being constructed, and 13 dams were tendered in 2015.

According to government estimations, once completed, the eight dams combined will be capable of holding 4,070 m3 of water for use in irrigating 38,400 hectares of agricultural land, and also contributing to the country’s flood prevention program. Additionally, some of the dams will be part of a hydroelectric facility. The facilities will have a total installed capacity of about 21 MW.

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Dams & Civil Structures

RusHydro completes stabilization work on Zagorskaya 2 pumped-storage plant
Russian energy giant JSC RusHydro has completed stabilization work on the Zagorskaya 2 pumped-storage plant.

HydroWorld.com reports that erosion of foundation soil under the 840 MW plant was caused by the “inefficient performance” of its impervious system after workers noticed water seeping into Zagorskaya 2’s turbine room. The turbine room and other areas were flooded via broken expansion joints and intakes of unfinished water pipes, caused by soil erosion that made the building sag.

RusHydro said the stabilization work began immediately with the erection of an earthfill dam on the tailrace side of the building.

As part of the rehabilitation programme the area adjacent to the building was completely drained by June, while a temporary support was formed beneath the basement plate to prevent further subsidence. The support was formed by drilling holes and injecting more than 20,000 cubic meters of “special fluid,” RusHydro said, while the turbine room was also cleared of sand drifts.

“The stabilization of the powerhouse lays ground to the next phase of rehabilitation — eventual restoration of the plant,” the company said in a statement.

RusHydro is currently considering a number of options for the project’s rehabilitation. The final plan will be chosen by the company jointly with external experts before being presented for approval to respective government agencies.

British ICE members revisit 1864 disaster to measure current standards
A devastating ‘Flood of 1864’ in Sheffield, England, during which the Dale Dyke Dam failed, remains the greatest civilian disaster of Victorian Britain. Failing on first filling, the release of water from the dam led to the loss of about 300 lives and extensive damage to property and infrastructure.

Marking the 150th Anniversary of the Dale Dyke Dam failure, Members of the British arm of the worldwide Institution of Civil Engineers will review the latest legislation in the UK on December 3, during a presentation by Dr. Andy Hughes. Director of dams and reservoirs at Atkins, Hughes is an All Reservoirs Panel engineer and is vice chairman of the British Dam Society. He has more than 35 years of experience in reservoir design and construction, both in the UK and internationally.

ICE will review UK implemented policy and procedure subsequent to the dam failure and how policy has helped to ensure the country’s reservoirs are maintained to legislated standards. Members will also discuss current industry guidance relating to dam break analysis, inundation mapping and emergency planning.

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