THE ORANGE-SENQU RIVER COMMISSION
REQUEST FOR EXPRESSIONS OF INTEREST (EOI) – CONSULTING FIRMS
Consultancy Services for the Lesotho to Botswana Water Transfer Conveyance System Technical Feasibility Study
Project Name: Preparation of the Lesotho Botswana Water Transfer (L-BWT)
AfDB Project ID: P-Z1-EAZ-061
Grant No.: 5150155003152
Sector: Water Resources Management
Countries: Lesotho, South Africa & Botswana
The Orange-Senqu River Basin Commission (ORASECOM) is a river basin organization established in 2000 by the Governments of South Africa, Namibia, Lesotho, and Botswana for managing the transboundary water resources of the Orange-Senqu River basin and promoting its beneficial development for socio-economic wellbeing and safeguarding the basin environment. ORASECOM was appointed Executing Agency for the pre-feasibility and feasibility studies for the Lesotho Botswana Water Transfer through a Memorandum of Agreement signed by South Africa, Botswana, and Lesotho in 2017, in the presence of Namibia, as an Observer.
A. Financing Information
ORASECOM has received financing from the African Development Bank toward the cost of preparation of the Lesotho-Botswana Water Transfer (L‑BWT) and intends to apply part of the agreed amount for this grant to payments under the contract for Consultancy Services for Technical Feasibility Study for the Lesotho to Botswana Water Transfer Conveyance System.
B. Overview of Water Transfer System
Conveyance System:
The LBWT Conveyance System is fully piped and will transport raw water from a weir located downstream of a Dam on the Makhaleng River in Lesotho, to a proposed outfall upstream of Nnywane Dam in Botswana over 688 km. Several major road, rail, and watercourse crossings were identified that will require special design considerations. There are nine off‑takes proposed to augment towns identified along the conveyance route in addition to the augmentation to Botswana.
Geotechnical Investigations:
Founding conditions in areas where the route traverses dolomites from Lichtenberg to the South African border with Botswana, and in areas that have been undermined in the Free State Goldfields, require consideration because of the risk of subsidence and seismicity associated with underground mining.
Pumping Requirements:
Elevations vary from 1850 to 1125 masl. Steel pipes with diameters ranging from 2200 mm to 1100 mm will deliver design flows ranging from 8731 l/s to 2735 l/s, resulting in pipe velocities between 1.3 m/s and 2.9 m/s. The total dynamic head requirement at the discharge in Botswana requires a combination of high lift pump stations, booster pump stations, and break-pressure tanks.
Hydropower Potential:
At Chainage 660.7 km, a 65 m residual head could generate up to 3.2 MW at peak flow, and at Chainage 688.5 km, a residual head of 118 m could generate 5.9 MW.
Pumped Storage Potential:
The high ground west of the dam site could be used to construct an upper storage dam at an elevation of 2000 m. The full supply level at the dam site is 1637 m. This could provide a static head in the order of 400 m. The distance between the two dams is 7 km. The additional water could be transferred from the Upper dam via a tunnel to near Matelile, from where it can gravitate via a pipeline to the conveyance route.
C. Invitation for Expressions of Interest
ORASECOM now invites eligible consulting firms to indicate their interest in providing services for this assignment. Interested consultants must provide information demonstrating their qualifications to perform the services (brochures, descriptions of similar assignments, experience under similar conditions, and availability of qualified staff, etc.).
D. Eligibility and Selection Procedure
Eligibility criteria, establishment of the short-list, and the selection procedure (Quality Cost Based Selection) shall be in accordance with the African Development Bank’s “Rules of Procedures for the Use of Consultants”, which is available on the Bank’s website at:
http://www.afdb.org
F. Submission of Expressions of Interest
Interested consultants may obtain further information from the contact addresses below.
Expressions of interest must be delivered in hard copy and soft copy to the address below to reach the Secretariat by 30th January 2026 at 4 PM (South Africa Standard Time).
Attention: Mr Comfort Molosiwa, The Executive Secretary
ORASECOM Secretariat
Tel: +27 12 663 6826
Address: The ORASECOM Secretariat, 269 Von Willich LN, South-East Cnr Von Willich LN & Lenchen Avenue,
Entrance Von Willich LN, Ground Floor, Block A, Corporate 66, Office Park, Centurion, South Africa.
E-mail:
Mr. Comfort Molosiwa – [email protected]
Copy: Eng. Victor Male – [email protected]