THE ORANGE–SENQU RIVER COMMISSION (ORASECOM)
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 and Botswana
BACKGROUND
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 to manage the transboundary water resources of the Orange–Senqu River Basin, promote its beneficial development for socio-economic wellbeing, and safeguard 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.
PROJECT FINANCING
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 grant amount to payments under the contract for Consultancy Services for the Technical Feasibility Study for the Lesotho to Botswana Water Transfer Conveyance System.
OVERVIEW OF THE WATER TRANSFER SYSTEM
The L-BWT 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 a distance of approximately 688 km.
Several major road, rail, and watercourse crossings have been identified and will require special design considerations. Nine off-takes are proposed to augment towns along the conveyance route, in addition to the augmentation to Botswana.
Geotechnical Investigations
Founding conditions along sections of the route traversing dolomites from Lichtenberg to the South African–Botswana border, as well as areas undermined in the Free State Goldfields, require careful consideration due to risks of subsidence and seismicity associated with underground mining.
Pumping Requirements
Elevations vary from 1,850 to 1,125 metres above sea level. Steel pipes with diameters ranging from 2,200 mm to 1,100 mm will deliver design flows ranging from 8,731 l/s to 2,735 l/s, resulting in pipe velocities between 1.3 m/s and 2.9 m/s. The total dynamic head requirement at the Botswana discharge point necessitates a combination of high-lift pump stations, booster pump stations, and break-pressure tanks.
Hydropower Potential
At Chainage 660.7 km, a residual head of 65 m could generate up to 3.2 MW at peak flow, while at Chainage 688.5 km, a residual head of 118 m could generate up to 5.9 MW.
Pumped Storage Potential
High ground west of the dam site could be used to construct an upper storage dam at an elevation of approximately 2,000 m, while the full supply level at the dam site is 1,637 m. This configuration could provide a static head of approximately 400 m. The distance between the two dams is approximately 7 km. Additional water could be transferred from the upper dam via a tunnel to near Matelile, from where it would gravitate via pipeline to the conveyance route.
INVITATION FOR EXPRESSIONS OF INTEREST
ORASECOM now invites eligible consulting firms to indicate their interest in providing services for this assignment. Interested firms must provide information demonstrating their qualifications to perform the services, including brochures, descriptions of similar assignments, experience under similar conditions, and availability of qualified staff.
SELECTION PROCEDURE
Eligibility criteria, establishment of the short-list, and the selection procedure (Quality- and Cost-Based Selection) shall be in accordance with the African Development Bank’s Rules of Procedure for the Use of Consultants, available on the Bank’s website at www.afdb.org.
SUBMISSION DETAILS
Interested consultants may obtain further information from the contact details below.
Expressions of Interest must be delivered in both hard copy and soft copy to the address below and must reach the ORASECOM Secretariat no later than 30 January 2026 at 16:00 (South Africa Standard Time).
CONTACT DETAILS
Attention: Mr Comfort Molosiwa, Executive Secretary
Organisation: ORASECOM Secretariat
Telephone: +27 12 663 6826
Address:
ORASECOM Secretariat
269 Von Willich Lane
South-East Corner of Von Willich Lane & Lenchen Avenue
Entrance: Von Willich Lane
Ground Floor, Block A
Corporate 66 Office Park
Centurion, South Africa
Email:
[email protected]
(Copy: [email protected])