Despite extensive delays caused by funding shortages, Covid-19 disruptions, contractor procurement issues and land/property disputes, the Clanwilliam Dam Wall Raising Project in the Western Cape is reported to have progressed to 47% complete in May.

The announcement was made by Water and Sanitation Deputy Minister David Mahlobo, during a budget and policy statement on May 15.

“The good news is that the emergency works to stabilise the dam wall are completed, which are critical in addressing the dam safety concerns,” said Mahlobo.

The project is fully funded from the fiscus and is projected to be completed by October 2028 at an estimated cost of R7-billion.

Once completed, the project will raise the dam wall by 13 m, increasing the dam’s storage capacity from about 122-million cubic metres to about 344-million cubic metres.

This expanded capacity is expected to increase the yearly water yield by between 70-million cubic metres and 82-million cubic metres, significantly improving water availability in the region.

The project will also enhance the dam’s safety and resilience during extreme flood events while supporting water allocation reform and creating opportunities for emerging farmers.

Additionally, it will strengthen long-term water security for agricultural, municipal and industrial users in the Lower Olifants Valley, contributing to economic growth, job creation and broader socioeconomic development across the West Coast region.

Project Scope

The raising of the dam wall is a multi-component regional infrastructure programme under the Olifants-Doorn River Water Resources Project.

Reportedly, the most critical component of the entire project is the remedial works to the dam’s foundations, which were found to require strengthening and foundation rehabilitation to safely withstand modern flood design standards, following dam safety investigations conducted in 2007.

Rather than simply raising the wall, engineers first had to address the stability of the underlying foundations and the existing concrete structure. These interventions were necessary because the raised reservoir would place greater hydraulic loads on the structure and expose it to larger flood events than the original design could accommodate.

Mahlobo confirmed that these works are complete.

The historic Old Cape Road, which runs through areas that will be affected by the increased water level once the dam is raised, must also be raised and realigned to maintain road access and safety, as well as preserve access to farms, tourism destinations and heritage sites in the valley.

Similarly, the Algeria Road crossing, which runs over the Olifants river, was also raised as the reservoir’s new full supply level would result in the previous river crossing being at increased risk of frequent flooding, reduced freeboard and structural vulnerability during high-flow events.

Additionally, some sections of the N7 national route near the reservoir margin will also be affected by the higher water level and will require realignment as well.

The major N7 realignment, for the section directly affected by the future reservoir, was completed by the South African National Roads Agency in 2017, but the current protection measures are to ensure that the route remains operational under the revised hydrological conditions.

Further, the upgrade and expansion of the conveyance network downstream of Bulshoek dam is being undertaken to effectively distribute water to users, to safeguard the economic value of the entire project.

The conveyance upgrade includes improving canal systems, expanding bulk water delivery infrastructure, modernising water distribution systems, improving irrigation efficiency as well as enabling water allocation reform.

The objective is to ensure that the additional water is effectively distributed to existing irrigators, municipalities and industries, while also meeting environmental flow requirements and expanding access to water allocations for emerging farmers who have historically been underserved.

Confirmed Contractors

Multidisciplinary construction group Stefanutti Stocks has been awarded the main construction contract to execute the civil engineering and wall-raising operations.

Infrastructure development and engineering firm Bigen Africa has been appointed as the site supervision and contract management service provider overseeing the project, while subcontractor, demolition and bulk earthworks specialists Phoenecian Group has been procured to handle the earthworks, drilling and blasting operations to prepare the various sites across the project for concrete works.