Polihali Dam

Last updated
Polihali Dam
Mokhotlong - Polihali Dam.png
Polihali Dam site location in Mokhotlong
Official namePolihali
Location Lesotho
Coordinates 29°17′S28°51′E / 29.29°S 28.85°E / -29.29; 28.85
Construction beganAugust 2023
Opening date2028 (planned)
Construction cost M 7.68 billion
Built bySinohydro Bureau 8 & 14 (China); Unik Civil Engineering (South Africa); Nthane Brothers (Lesotho)
Dam and spillways
Type of dam Concrete faced rock-fill
Impounds Senqu River
Height165 m (541 ft)
Width (crest)915 metres (3,002 ft)
Reservoir
Total capacity2,325 million m3
Normal elevation1,940 m (6,360 ft) above sea level

The Polihali Dam is a concrete faced rock-fill dam under construction in Lesotho. [1] It is the third dam, under the Phase II of the series of dams of the proposed Lesotho Highlands Water Project (LHWP), which will eventually include five large dams in remote rural areas of Lesotho and South Africa. [1] The Polihali Transfer Tunnel, which will link this dam to the Katse Dam (the focal point of the LHWP), spans a length of 38 kilometers with a nominal bore of five metres. [2] This tunnel will convey water via gravity from the Polihali reservoir to the Katse reservoir. From Katse, water is then conveyed to Phase I's Muela Hydropower Station and subsequently directed to the As River en route to Gauteng, South Africa. [3]

Contents

Development

The second phase of the Lesotho Highlands Water Project encompasses the construction of the Polihali Dam, the Polihali Transfer Tunnel, the Oxbow Hydropower Scheme, and three major bridges. [4] Adding 2325 million cubic meters in storage capacity, it will elevate the annual supply rate from 780 to 1270 million cubic meters, meeting South Africa's water demands while enhancing Lesotho's power generation capacity. [3]

The awarding of construction contracts for the Polihali Dam (approx. M7.68 billion), Polihali Tunnel (approx. M9.2 billion), and Senqu Bridge (the largest of the three major bridges planned) occurred in late 2022. [3] The majority of the funds needed for this second phase will be sourced from South Africa's financial markets by the Trans Caledon Tunnel Authority. [5] The procurement for the design and construction supervision of the Oxbow Hydropower Scheme has started with March 2023, as deadline for the submission of bids of engineering, environmental and social consultants. [3]

The construction of the Polihali Dam and the subsequent filling of the reservoir will encompass more than 5,000 hectares of land bordering the Senqu and Khubela rivers. Around 270 families will undergo resettlement. Initial resettlement homes in the Mokhotlong district were delivered in early April 2023, with further resettlements to follow as new residences are completed. [4] Amnesty International warns that the Polihali Dam project could displace nearly 8,000 people from 35 villages, threatening their homes and livelihoods. The organization calls on the Lesotho authorities to ensure that any evictions related to the Polihali Dam project are carried out in accordance with international human rights standards. [6] Additionally, numerous local news articles have highlighted the complaints of residents. These concerns encompass the compensation provided for their land, the handling of their animals that wandered into the construction zone, and the low wages given to local laborers. [7]

"I would like to emphasise that the Lesotho Highlands Water Project is more than just a water project. It is a beacon of hope, a symbol of progress, a symbol of international cooperation, and a testament to the strength of bilateral relations between the Kingdom of Lesotho and the Republic of South Africa. We are determined that this massive trans-border project should equally benefit the peoples of Lesotho and South Africa. In addition to the royalties Lesotho receives from the Lesotho Highlands Water Project, local jobs have been created and new roads have been built in the Kingdom. Both Phase I and II include the construction of hydropower facilities to provide electricity for Lesotho. It has been critical for us as both Lesotho and South Africa that all communities affected by the construction of the Polihali Dam were consulted, that there should be fair compensation and relocation to alternative housing nearby."

President Ramaphosa's speech during the launch of Phase 2 of the LHWP at Polihali [5]

In May 2023, Lesotho's King Letsie III and South Africa's President Cyril Ramaphosa officially launched the project. [4] Months later, the Lesotho Highlands Development Authority (LHDA) reported that on Friday, 4 August 2023, the team successfully diverted the Senqu River through the pre-cofferdam. [1] The purpose of the pre-cofferdam is to channel the river through diversion tunnels, ensuring the safe construction of both the cofferdam and the main dam foundations. The goal is to finish the cofferdam by late October 2023, followed by the commencement of work on the main dam.

See also

Related Research Articles

<span class="mw-page-title-main">Kariba Dam</span> Dam in Zambia, Zimbabwe

The Kariba Dam is a double curvature concrete arch dam in the Kariba Gorge of the Zambezi river basin between Zambia and Zimbabwe. The dam stands 128 metres (420 ft) tall and 579 metres (1,900 ft) long. The dam forms Lake Kariba, which extends for 280 kilometres (170 mi) and holds 185 cubic kilometres (150,000,000 acre⋅ft) of water.

<span class="mw-page-title-main">Orange River</span> Major river in southern Africa

The Orange River is a river in Southern Africa. It is the longest river in South Africa. With a total length of 2,432 km (1,511 mi), the Orange River Basin extends from Lesotho into South Africa and Namibia to the north. It rises in the Drakensberg mountains in Lesotho, flowing westwards through South Africa to the Atlantic Ocean. The river forms part of the international borders between South Africa and Lesotho and between South Africa and Namibia, as well as several provincial borders within South Africa. Except for Upington, it does not pass through any major cities. The Orange River plays an important role in the South African economy by providing water for irrigation and hydroelectric power. The river was named the Orange River in honour of the Dutch ruling family, the House of Orange, by the Dutch explorer Robert Jacob Gordon. Other names include simply the word for river, in Khoekhoegowab orthography written as !Garib, which is rendered in Afrikaans as Gariep River with the intrusion of a velar fricative in place of the alveolar click, Groote River or Senqu River, derived from ǂNū "Black". It is known in isiZulu as isAngqu.

<span class="mw-page-title-main">Vaal River</span> Tributary of the Orange River, South Africa

The Vaal River is the largest tributary of the Orange River in South Africa. The river has its source near Breyten in Mpumalanga province, east of Johannesburg and about 30 kilometres (19 mi) north of Ermelo and only about 240 kilometres (150 mi) from the Indian Ocean. It then flows westwards to its confluence with the Orange River southwest of Kimberley in the Northern Cape. It is 1,458 kilometres (906 mi) long, and forms the border between Mpumalanga, Gauteng and North West Province on its north bank, and the Free State on its south.

<span class="mw-page-title-main">Katse Dam</span> Dam in Lesotho

The Katse Dam, a concrete arch dam on the Malibamat'so River in Lesotho, is Africa's second largest double-curvature arch dam.. The dam is part of the Lesotho Highlands Water Project, which will eventually include five large dams in remote rural areas. The dam is just below the confluence of the Bokong River, which forms the western arm of the Katse reservoir.

<span class="mw-page-title-main">Lesotho Highlands Water Project</span> Water Supply and hydropower project by South Africa and Lesotho

The Lesotho Highlands Water Project (LHWP) is an ongoing water supply project with a hydropower component, developed in partnership between the governments of Lesotho and South Africa. It comprises a system of several large dams and tunnels throughout Lesotho and delivers water to the Vaal River System in South Africa. In Lesotho, it involves the rivers Malibamatso, Matsoku, Senqunyane, and Senqu. It is Africa's largest water transfer scheme.

<span class="mw-page-title-main">Tarbela Dam</span> Dam in Khyber Pakhtunkhwa, Pakistan

Tarbela Dam is an earth-filled dam along the Indus River in Pakistan's Khyber Pakhtunkhwa province. It is located mainly in the Swabi District Tehsil Topi of the province. It is about 20 km (10 mi) from the city of Swabi KPK, 105 km (65 mi) northwest of Islamabad, and 125 km (80 mi) east of Peshawar. It is the largest earth-filled dam in the world. The dam is 143 metres (470 ft) high above the riverbed and its reservoir, Tarbela Lake, has a surface area of approximately 250 square kilometres (97 sq mi).

<span class="mw-page-title-main">Bui Dam</span> Hydroelectric project in Ghana

The Bui Dam is a 400-megawatt (540,000 hp) hydroelectric project in Ghana. It is built on the Black Volta river at the Bui Gorge, at the southern end of Bui National Park. The project was a collaboration between the government of Ghana and Sino Hydro, a Chinese construction company. Construction on the main dam began in December 2009. Its first generator was commissioned on 3 May 2013, and the dam was inaugurated in December of the same year.

<span class="mw-page-title-main">Mohale Dam</span> Dam in Lesotho

Mohale Dam is a concrete faced rock-fill dam in Lesotho. It is the second dam, under Phase 1B of the series of dams of the proposed Lesotho Highlands Water Project (LHWP), which will eventually include five large dams in remote rural areas of Lesotho and South Africa. The project has been built at a cost of US$1.5 billion.

<span class="mw-page-title-main">Senqunyane River</span> River in Lesotho

The Senqunyane River is a river of central Lesotho. The river rises in the Maluti Mountains in northwest Lesotho, and flows southwards and then westwards for 120 kilometres before joining the Senqu River in the southwest.

<span class="mw-page-title-main">Malibamat'so River</span>

The Malibamat'so River is a river in northern Lesotho. Its origin is near to the South African border, where it drains the eastern slopes of the Maloti Range. It flows southwards past the village of Lejone, and eventually joins the Senqu River 5 kilometres (3.1 mi) northeast of Mohlanapeng.

<span class="mw-page-title-main">Orange–Fish River Tunnel</span> Irrigation tunnel in South Africa

The Orange–Fish Tunnel, constructed between 1966 and 1975, is an 82.8-kilometre (51.4-mile) long irrigation tunnel in central South Africa, built to divert water from the Orange River to the Fish River valley. It is the longest continuous enclosed aqueduct in the southern hemisphere.

<span class="mw-page-title-main">Interbasin transfer</span>

Interbasin transfer or transbasin diversion are terms used to describe man-made conveyance schemes which move water from one river basin where it is available, to another basin where water is less available or could be utilized better for human development. The purpose of such water resource engineering schemes can be to alleviate water shortages in the receiving basin, to generate electricity, or both. Rarely, as in the case of the Glory River which diverted water from the Tigris to Euphrates River in modern Iraq, interbasin transfers have been undertaken for political purposes. While ancient water supply examples exist, the first modern developments were undertaken in the 19th century in Australia, India and the United States, feeding large cities such as Denver and Los Angeles. Since the 20th century many more similar projects have followed in other countries, including Israel and China, and contributions to the Green Revolution in India and hydropower development in Canada.

The Kandadji Dam, is a large multipurpose dam under construction on the Niger River. The site is situated near the small town of Kandadji, Tillabéri Department, Tillabéri Region, Niger, 180 km northwest of the capital Niamey. It is being built by the Haut Commissariat à l'Aménagement de la Vallée du Niger, a public body under the Primer Minister's Office.

<span class="mw-page-title-main">As River</span> River in South Africa

The As River is a tributary of the Liebenbergsvlei River in the eastern Free State, South Africa. Since 1968 it is impounded by the Sol Plaatje Dam at its confluence with the latter river, just east of Bethlehem. Its origin is some 35 km southeast of Bethlehem, on the northern slopes of the Rooiberge, near Clarens. With the opening of the northern delivery tunnel of the Lesotho Highlands Water Project in 1998, the once tiny stream was transformed to a strong-flowing river.

Ethiopia is called the water tower of Africa due to its combination of mountainous areas with a comparatively large share of water resources in Africa. Only a fraction of this potential has been harnessed so far, 1% at the beginning of the 21st century. In order to become the powerhouse of Africa, Ethiopia is actively exploiting its water resources by building dams, reservoirs, irrigation and diversion canals and hydropower stations. The benefits of the dams are not only limited to hydropower. Many dams are multi-purpose dams that are also designed to provide water for irrigation, drinking water and flood control. However, hydropower is expected to be the main benefit of the dams.

<span class="mw-page-title-main">Upper Kotmale Dam</span> Dam in Talawakele, Nuwara Eliya

The Upper Kotmale Dam is located in Talawakele, within the Nuwara Eliya District, in the Central Province of Sri Lanka. The dam feeds the third largest hydroelectric power station in the country.

<span class="mw-page-title-main">Neelum–Jhelum Hydropower Plant</span> Hydropower station in Azad Kashmir, Pakistan

The Neelum–Jhelum Hydropower Plant is part of a run-of-the-river hydroelectric power project in Azad Kashmir (AJK) designed to divert water from the Neelum River to a power station on the Jhelum River. The power station is located 42 km (26 mi) south of Muzaffarabad, and has an installed capacity of 969 MW. Construction on the project began in 2008 after a Chinese consortium was awarded the construction contract in July 2007. After many years of delays, the first generator was commissioned in April 2018 and the entire project was completed in August 2018 when the fourth and last unit was synchronized with the national grid on 13 August and attained its maximum generation capacity of 969 MW on 14 August 2018. It will generate 5,150 GWh per year at the levelised tariff of Rs 13.50 per unit for 30 years.

The Dasu Dam is a large hydroelectric gravity dam currently under construction on the Indus River near Dasu in Kohistan District, Khyber Pakhtunkhwa Province, Pakistan. It is developed by Pakistan Water and Power Development Authority (Wapda), as a key component of the company's Water Vision 2025. The project was started in 2019 but faced a delay due to funds and land acquisition disputes. Work resumed in 2020 after land acquisition and arrangements of funding facility, the World Bank agreed to contribute $700 million of the $4.2 billion as the government of Imran Khan decided to proceed ahead with the construction of the project, as part of his vision of reducing Pakistan's reliance on non-renewable energy.

<span class="mw-page-title-main">Lesotho Highlands</span> Natural region in Lesotho

The Lesotho Highlands are formed by the Drakensberg and Maloti mountain ranges in the east and central parts of the country of Lesotho. Foothills form a divide between the lowlands and the highlands. Snow is common in the highlands in the winter.

Lesotho is a mountainous and fairly 'water-rich country', but suffers from a lack of clean drinking water due to inadequate sanitation. In recent decades, with the construction of dams for the Lesotho Highlands Water Project (LHWP), Lesotho has become the main provider of water to parts of northern South Africa. Despite the economic and infrastructure development occasioned by the LHWP, waterborne diseases are common in the country and the infant mortality rate from them is high. In 2017, a project to improve the rural water supply in the Lesotho Lowlands was funded by the Global Environment Facility and the African Development Bank, and is ongoing.

References

  1. 1 2 3 "Polihali Dam marks significant milestone with Senqu River diversion". International Water Power. Retrieved 4 April 2024.
  2. "Polihali Transfer Tunnel Update" (PDF). Lesotho Highlands Water Project (LHWP).
  3. 1 2 3 4 "Construction of Polihali Dam and Polihali Transfer Tunnel will start as contracts awarded". geoengineer.org. November 8, 2022. Retrieved May 8, 2024.
  4. 1 2 3 "Lesotho Highlands Development Authority : The Epitome of Dam Expertise". Africa Outlook Magazine. Retrieved 6 May 2024.
  5. 1 2 "President Ramaphosa turns sod in Lesotho water project". sanews.gov.za. South African Government News Agency. May 23, 2023. Retrieved May 8, 2024.
  6. "Lesotho: Polihali Dam construction puts nearly 8,000 people at risk of displacement". amnesty.org. Amnesty International. February 6, 2020. Retrieved May 8, 2024.
  7. Molupe, Majara (June 22, 2023). "Basotho lose out over new dam that will supply SA with more water". mg.co.za. Mail & Guardian. Retrieved May 8, 2024.