Yeywa Dam
Encyclopedia
The Yeywa Hydropower
Dam
, located on the Myitnge River
, 52 km (32.3 mi) southeast of Mandalay
city, at Yeywa village in Kyaukse Township
, Mandalay Division
in central Myanmar
, is the country's first roller-compacted concrete
(RCC) dam, and the site of a 790-MW hydroelectric power plant, the largest in the country.
with a consortium of Chinese companies created by China International Trust & Investment Co. (CITIC) and Sinohydro Corporation
for implementation of the project. On September 2, 2005, a ceremony to mark the signing of contract between the Hydroelectric Power Department under the Ministry of Electric Power and the China National Heavy Machinery Corporation (CHMC) for the Yeywa Hydroelectric Power Project was held in Yangon
[Rangoon], Site work began in 2004 and is expected to be complete by the end of 2010.
The dam design comprises a 197 m (646.3 ft) high RCC embankment gravity dam, built of 2800000 cubic metres (3,662,261.7 cu yd) of concrete. The dam includes an ungated spillway
of reinforced conventional concrete cast after RCC placement, located in the central section of the dam for a design flood water discharge of 6600 m³ (5.4 acre·ft)/s. The 448 ft (136.6 m) wide spillway consists of eight 56 ft (17.1 m) wide and 39 ft (11.9 m) high outlets.
There is a 790 MW (4 × 197.5 MW) powerhouse at the toe of the dam on the south bank of the river. The power house containing the turbines and generators is 510 ft (155.4 m) long, 148 ft (45.1 m) wide and 197 ft (60 m) high. The power house and dam structures are designed to withstand earthquakes of up to eight on the Richter scale.
The power generation facilities consist of four water intakes, each consisting of 22 ft (6.7 m) diameter and 492 ft (150 m) long high tensile steel pipe penstock
s and 4 vertical axis Francis turbine
s and generator units
and associated electro-mechanical and auxiliary equipment installed in an open air powerhouse. Four water intake towers were built as conventional reinforced concrete structures abutting the upstream (east) face of the RCC dam. This enabled the contractor to build the towers above the penstock inlets before the start of RCC construction in order to minimise interference with the RCC construction activity.
There is one permanent 10 m (32.8 ft) diameter, 450 m (1,476.4 ft) long, diversion tunnel in the north river bank serving as a bottom outlet. This outlet tunnel enables reservoir drawdown and control during reservoir filling, maintenance of downstream riparian river flow during the impounding period and, together with the spillway, erves to redirect flood waters of the Myitnge river and maintain river flow during an emergency when all turbines are closed down.
Two double circuit 230 kV
transmission lines
connect the main transformers located on the downstream side of the powerhouse to an open-air switchyard, located on the south river bank 550 m (1,804.5 ft) downstream of the powerhouse. The Yeywa Dam will supply electric power to the Meiktila Sub-Power Station
through the 110 km (68.4 mi) long Yeywa-Meiktila 230 kV double power line link to the southwest and to the Bellin Substation through another 50 km long 230 kV double power line link in the west. The Bellin and the Meiktila Sub-Power Stations will be linked to each other with 100 km long 23 kV double power lines. US$ 45.8 million worth of 230 KVA cables and equipment were used for construction and linking of these sub- power stations.
, Switzerland
, and Britain
have been involved in various stages of the Yeywa Dam, including the Chinese companies: Export-Import Bank of China (China Exim Bank), China Gezhouba Group Co.
(CGGC), China National Electric Equipment Co., Hunan Savoo Overseas Water & Electric Engineering Co. and China National Heavy Machinery Co. The Swiss company COLENCO Power Engineering, Ltd., the Germany based company Voith Siemens and the British Malcolm Dunstan & Associates.
A key aspect in the successful construction of the Yeywa RCC dam was comprehensive training of the local staff during preparative for and initial stages of the construction. Up to 5,000 workers were employed on this large construction project. Equipment selected for the concreting operations include Putzmeister’s MX 32 stationary boom, an M 38 truck-mounted concrete pump and two BSA 2,109 HP stationary pumps.
A bridge was built across the river, just downstream of the dam, to replace the ferry
system, which previously was the only means for transport across the river.
In 2005 the Myanmar Times reported that three villages near the dam had been relocated. The villagers had depended on the Myitnge River for their fishing, farming and logging livelihoods, the sources of which will be flooded by the dam. Ancient cultural sites like the Sappa Sukha Htattaw Temple will also be flooded and forever lost.
Hydroelectricity
Hydroelectricity is the term referring to electricity generated by hydropower; the production of electrical power through the use of the gravitational force of falling or flowing water. It is the most widely used form of renewable energy...
Dam
Dam
A dam is a barrier that impounds water or underground streams. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are...
, located on the Myitnge River
Myitnge River
Myitnge River in Myanmar . The name Myitnge in Burmese and Dokhtawaddy in Pali both mean "little river" in comparison with the Ayeyarwady or "big river".-Source, course and outflow:...
, 52 km (32.3 mi) southeast of Mandalay
Mandalay
Mandalay is the second-largest city and the last royal capital of Burma. Located north of Yangon on the east bank of the Irrawaddy River, the city has a population of one million, and is the capital of Mandalay Region ....
city, at Yeywa village in Kyaukse Township
Kyaukse Township
Kyaukse Township is a township of Kyaukse District in the Mandalay Division of Burma. It makes up the area including the town of Kyaukse. Yeywa Dam is located there....
, Mandalay Division
Mandalay Division
Mandalay Region is an administrative division of Myanmar. It is located in the center of the country, bordering Sagaing Region and Magway Region to the west, Shan State to the east, and Bago Region and Kayin State to the south. The regional capital is Mandalay. In the south of the division lies...
in central Myanmar
Myanmar
Burma , officially the Republic of the Union of Myanmar , is a country in Southeast Asia. Burma is bordered by China on the northeast, Laos on the east, Thailand on the southeast, Bangladesh on the west, India on the northwest, the Bay of Bengal to the southwest, and the Andaman Sea on the south....
, is the country's first roller-compacted concrete
Roller-compacted concrete
Roller-compacted concrete or rolled concrete is a special blend of concrete that has essentially the same ingredients as conventional concrete but in different ratios, and increasingly with partial substitution of fly ash for Portland cement. RCC is a mix of cement/fly ash, water, sand, aggregate...
(RCC) dam, and the site of a 790-MW hydroelectric power plant, the largest in the country.
Background
The plant feasibility study was done in 1999. In May 2001, agreement of consulting service between MEPE and COLENCO Power Engineering, Ltd. had signed. In 2003 agreement part 2 for Detail Design, preparation of tender documents and guidance services for construction supervision was signed. The river diversion was completed on December 12, 2004 and RCC placement began on February 8, 2006. The Burmese government announced plans for the Yeywa Dam in late 2001. In 2004, Burma’s Ministry of Electric Power (MEPE) signed a MOUMOU
MOU, MoU, Mou or mou may refer to:* Memorandum of understanding* Minutes of Use, in telecommunication operations* Ministry of Unification, a branch of the South Korean government.* The Museum of Osaka University...
with a consortium of Chinese companies created by China International Trust & Investment Co. (CITIC) and Sinohydro Corporation
Sinohydro Corporation
Sinohydro Corporation is a Chinese state-owned hydropower engineering and construction company. It is the world's largest hydroelectric company...
for implementation of the project. On September 2, 2005, a ceremony to mark the signing of contract between the Hydroelectric Power Department under the Ministry of Electric Power and the China National Heavy Machinery Corporation (CHMC) for the Yeywa Hydroelectric Power Project was held in Yangon
Yangon
Yangon is a former capital of Burma and the capital of Yangon Region . Although the military government has officially relocated the capital to Naypyidaw since March 2006, Yangon, with a population of over four million, continues to be the country's largest city and the most important commercial...
[Rangoon], Site work began in 2004 and is expected to be complete by the end of 2010.
Design
Spillway
A spillway is a structure used to provide the controlled release of flows from a dam or levee into a downstream area, typically being the river that was dammed. In the UK they may be known as overflow channels. Spillways release floods so that the water does not overtop and damage or even destroy...
of reinforced conventional concrete cast after RCC placement, located in the central section of the dam for a design flood water discharge of 6600 m³ (5.4 acre·ft)/s. The 448 ft (136.6 m) wide spillway consists of eight 56 ft (17.1 m) wide and 39 ft (11.9 m) high outlets.
There is a 790 MW (4 × 197.5 MW) powerhouse at the toe of the dam on the south bank of the river. The power house containing the turbines and generators is 510 ft (155.4 m) long, 148 ft (45.1 m) wide and 197 ft (60 m) high. The power house and dam structures are designed to withstand earthquakes of up to eight on the Richter scale.
The power generation facilities consist of four water intakes, each consisting of 22 ft (6.7 m) diameter and 492 ft (150 m) long high tensile steel pipe penstock
Penstock
A penstock is a sluice or gate or intake structure that controls water flow, or an enclosed pipe that delivers water to hydraulic turbines and sewerage systems. It is a term that has been inherited from the technology of wooden watermills....
s and 4 vertical axis Francis turbine
Francis turbine
The Francis turbine is a type of water turbine that was developed by James B. Francis in Lowell, Massachusetts. It is an inward-flow reaction turbine that combines radial and axial flow concepts....
s and generator units
Electrical generator
In electricity generation, an electric generator is a device that converts mechanical energy to electrical energy. A generator forces electric charge to flow through an external electrical circuit. It is analogous to a water pump, which causes water to flow...
and associated electro-mechanical and auxiliary equipment installed in an open air powerhouse. Four water intake towers were built as conventional reinforced concrete structures abutting the upstream (east) face of the RCC dam. This enabled the contractor to build the towers above the penstock inlets before the start of RCC construction in order to minimise interference with the RCC construction activity.
There is one permanent 10 m (32.8 ft) diameter, 450 m (1,476.4 ft) long, diversion tunnel in the north river bank serving as a bottom outlet. This outlet tunnel enables reservoir drawdown and control during reservoir filling, maintenance of downstream riparian river flow during the impounding period and, together with the spillway, erves to redirect flood waters of the Myitnge river and maintain river flow during an emergency when all turbines are closed down.
Two double circuit 230 kV
Volt
The volt is the SI derived unit for electric potential, electric potential difference, and electromotive force. The volt is named in honor of the Italian physicist Alessandro Volta , who invented the voltaic pile, possibly the first chemical battery.- Definition :A single volt is defined as the...
transmission lines
Electric power transmission
Electric-power transmission is the bulk transfer of electrical energy, from generating power plants to Electrical substations located near demand centers...
connect the main transformers located on the downstream side of the powerhouse to an open-air switchyard, located on the south river bank 550 m (1,804.5 ft) downstream of the powerhouse. The Yeywa Dam will supply electric power to the Meiktila Sub-Power Station
Electrical substation
A substation is a part of an electrical generation, transmission, and distribution system. Substations transform voltage from high to low, or the reverse, or perform any of several other important functions...
through the 110 km (68.4 mi) long Yeywa-Meiktila 230 kV double power line link to the southwest and to the Bellin Substation through another 50 km long 230 kV double power line link in the west. The Bellin and the Meiktila Sub-Power Stations will be linked to each other with 100 km long 23 kV double power lines. US$ 45.8 million worth of 230 KVA cables and equipment were used for construction and linking of these sub- power stations.
Construction
Several construction companies from ChinaChina
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
, Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....
, and Britain
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
have been involved in various stages of the Yeywa Dam, including the Chinese companies: Export-Import Bank of China (China Exim Bank), China Gezhouba Group Co.
National Innovative Enterprises
In the [People's Republic of China], National Innovative Enterprises are a group of 91 companies chosen by the Ministry of Science and Technology from an original list of 103 firms following a two-year trial period...
(CGGC), China National Electric Equipment Co., Hunan Savoo Overseas Water & Electric Engineering Co. and China National Heavy Machinery Co. The Swiss company COLENCO Power Engineering, Ltd., the Germany based company Voith Siemens and the British Malcolm Dunstan & Associates.
A key aspect in the successful construction of the Yeywa RCC dam was comprehensive training of the local staff during preparative for and initial stages of the construction. Up to 5,000 workers were employed on this large construction project. Equipment selected for the concreting operations include Putzmeister’s MX 32 stationary boom, an M 38 truck-mounted concrete pump and two BSA 2,109 HP stationary pumps.
A bridge was built across the river, just downstream of the dam, to replace the ferry
Ferry
A ferry is a form of transportation, usually a boat, but sometimes a ship, used to carry primarily passengers, and sometimes vehicles and cargo as well, across a body of water. Most ferries operate on regular, frequent, return services...
system, which previously was the only means for transport across the river.
Impact
3,550 Gigawatt hours of electricity per year will be supplied to the Mandalay Division regional power grid for public and private consumption.In 2005 the Myanmar Times reported that three villages near the dam had been relocated. The villagers had depended on the Myitnge River for their fishing, farming and logging livelihoods, the sources of which will be flooded by the dam. Ancient cultural sites like the Sappa Sukha Htattaw Temple will also be flooded and forever lost.