Name of the Project
Clanwilliam dam and irrigation scheme upgrade project.

Location
On the Olifants river, in the Western Cape, South Africa.

Project Owner/s
The stakeholders include the Department of Water and Sanitation (DWS), the Lower Olifants River Water User Association; the Cederberg, Matzikama and West Coast municipalities; the Western Cape provincial government; the South African National Roads Agency Limited (Sanral); and power utility Eskom.

Project Description
This is the second-biggest infrastructure project being undertaken in the Western Cape and is part of the Olifants River Water Resources Project. 

The Clanwilliam dam was built in 1935 and was raised to its current level, with a storage capacity of 128-million cubic metres, in the 1960s.

A feasibility study completed on the project in October 2007 found that raising the wall by 13 m is technically feasible and economically viable. The study also found that the dam needs to be strengthened.

The proposed project will improve the safety of the dam and increase the yearly yield of the dam by 69.5-million cubic metres, of which a portion will be used to assist with the development of resource-poor farmers.

The project will include:

• remedial works to the dam’s foundations;
• the raising and realigning of portions of Old Cape road;
• raising the Algeria road crossing over the Olifants river;
• protecting the N7 towards Citrusdal;
• maintenance of farm roads and residences along Renbaan road;
• upgrading and expanding the conveyance network downstream of Bulshoek dam; and
• other affected infrastructure, including a hydropower plant.

Potential Job Creation
The project has the potential to create about 3 800 permanent jobs.

Capital Expenditure
R6-billion.

Planned Start/End Date
The project is expected to be completed by May 2029.

Latest Developments
The construction of the coffer wall – a temporary structure designed to hold back water and create a dry-work environment during the rainy seasons – was completed in mid-September 2025.

As at December 2025, the emergency work on the lower spillway was 70% complete, and the overall project progress had increased to 26%.

The completion of intake tower excavations is expected in June 2026, and the start of concrete works on the left bank during 2026.

Once completed, the newly raised dam will produce numerous benefits, such as maintaining ecological requirements of the Olifants river, improving water supply to existing irrigators and creating “much-needed” job opportunities for the local community.

The DWS expects that the project will reach 95% capacity by October 1. 

Key Contracts, Suppliers and Consultants
None stated.

Contact Details for Project Information
Department of Water and Sanitation director media liaison Wisane Mavasa, tel +27 12 336 8264 or email mavasaw@dws.gov.za.