The Lesotho Highlands Development Authority (LHDA) has crossed another milestone in the implementation of Phase II of the Lesotho Highlands Water Project (LHWP).

Following the completion of further feasibility studies into the hydropower component of Phase II, which recommended conventional hydropower as the more feasible option to meet Lesotho’s energy needs, the authority started the procurement process for the design and construction supervision of the Oxbow Hydropower Scheme.

Three potential sites were identified, two on the Senqu river and the third at Oxbow, on the Malibamat’so river, after the Lesotho government, in November 2021, confirmed the Oxbow Hydropower Scheme and gave the go-ahead for the hydropower engineering, environmental and social-impact assessment (ESIA) and the resettlement action planning (RAP) studies.

“The procurement for the associated ESIA and RAP is taking place concurrently,” says LHDA CEO Tente Tente.

The scope of the hydropower engineering includes a 100-m-high dam; two tunnels; a high-pressure steel penstock (pipeline); an 80 MW power station; a 132 kV transmission line; all associated infrastructure such as roads and accommodation; bulk power; and telecommunications infrastructure and envirosocial components.

Broadly, the envirosocial components will include studies on public health, cultural heritage, terrestrial ecology and water quality elements, resettlement and livelihoods restoration elements to mitigate the impact of the Oxbow Scheme on the environment and communities in the project area.

“The Oxbow Hydropower Scheme is the third major engineering component of Phase II. LHDA is confident that it will attract the interest of local, regional and international consultancies with the experience and expertise to deliver engineering projects of this nature. Given its scope, it will be a significant boost to the engineering and construction sector and the economy of the region,” Tente continues.

Further, the Oxbow Hydropower Scheme increases security of power for Lesotho and educes the country’s dependence on electricity imports.

“The power generated at Oxbow adds to the additional 40% of electricity that will be generated at ‘Muela as a result of the increased flow of water from Polihali,” adds LHDA Phase II divisional manager Ntsoli Maiketso.

Water transfer to South Africa starts in 2028 with the completion of the Polihali dam and Polihali transfer tunnel. The Oxbow Hydropower Scheme will be commissioned in 2029.

Interested firms have until March 13, 2023, to submit their technical and financial proposals for professional services for the design and construction supervision of the Oxbow Hydropower Scheme.

The LHWP is a multidisciplinary, multiphase, binational project undertaken by Lesotho and South Africa that will harness the water resources of the highlands of Lesotho through the construction of a series of dams and tunnels for the mutual benefit of both countries.

The first phase of the four-phased project was completed in 2003, while Phase II, which comprises the construction of a water-transfer component and a hydropower component, each involving the construction of a dam, tunnels, infrastructure including roads and services, and associated environmental, health and social studies, is currently under way.