Senteeko Dam: facts, rumours and what residents need to know

Over the past few days, a series of social media posts and WhatsApp messages have caused understandable concern among residents, farmers and businesses in the greater Barberton and De Kaap Valley areas. Messages warning of a possible collapse of the Senteeko Dam wall, and the risk of large-scale flooding downstream, spread rapidly online, in some cases escalating into panic. The dam was built many years ago to sustain the Senteeko Tea Estate.

De Kaap Echo does not typically cover hard news. However, given the scale of concern, the safety implications, and the fact that many residents are not active on social media, we believe it is important to share verified information and place the situation in proper context.

The initial alarm was raised by a concerned citizen who shared a video of increased outflow at the Senteeko Dam, stating that the dam wall appeared to be failing due to the high amount of rainfall and water flowing into the dam. The post warned that, should the wall collapse, approximately 1.82 million cubic metres of water could rush into the Suidkaap River system, affecting downstream areas.

This was followed by messages that an emergency evacuation order had been issued by the City of Mbombela and listing rivers and settlements potentially at risk, including the Suidkaap, De Kaap, Kaap and Crocodile rivers.

While some of this information was based on genuine concerns and early warnings, not all posts reflected the latest official assessments, leading to confusion and heightened anxiety.

Barberton Ward Councillor, Phillip Minnaar, has since been providing regular, verified updates to the community, based on information from the De Kaap Irrigation Board, engineers on site, and disaster management structures.

According to these updates:

• The Senteeko Dam wall is still standing, but is not stable and shows signs of structural deterioration.
• The dam has not yet collapsed.
• A technical engineering team, including specialists from Gauteng, has been dispatched to assess the dam and oversee mitigation measures.

All relevant authorities, including the City of Mbombela and Ehlanzeni Disaster Management, have been formally notified and are involved.

An engineering assessment shared on January 20 at 16:00 provides important clarity on the situation. If the Senteeko Dam were to fail, it would take several hours to empty, not result in an instantaneous surge. The Barberton Valley and upper reaches of the De Kaap River would be the most affected areas. Water would eventually reach the Crocodile River, but the flow rate would slow significantly as it moves downstream.

At the time of assessment, the De Kaap River was flowing at approximately 40 cubic metres per second, down from 70 cubic metres per second the previous night. The Crocodile River was flowing at around 300 cubic metres per second near Kaapmuiden.

Engineers estimate that a dam failure would add no more than 50 cubic metres per second to the Crocodile River flow near Matsulu, lasting for approximately eight hours. This would result in river levels similar to those already experienced during recent peak flows.

In practical terms, this means that he Crocodile River is not expected to exceed levels seen in the past two weeks. There is no cause for alarm along the Crocodile River specifically related to the Senteeko Dam.

While widespread panic is not warranted, authorities stress that localized risk remains, particularly along the Suidkaap and De Kaap rivers, especially in their upper reaches. Low-level river crossings and bridges, could become dangerous very quickly.

Residents and farmers in low-lying areas close to these rivers are advised to heed evacuation warnings, remain alert, and move to higher ground if instructed to do so.

Importantly, residential areas in Barberton town itself are not expected to be affected.

The latest preliminary feedback from dam safety engineers on January 21 indicates the following.

Undercutting at the main spillway channel is worsening, with part of the slab now partially unsupported. The outlet valve has been fully opened, although it has not significantly reduced water levels. There is no overtopping or excessive seepage elsewhere on the dam structure.

To reduce risk, plans are underway to construct a temporary side-channel spillway by excavating a trench to relieve pressure on the main spillway. This will be carried out under the supervision of the Approved Professional Person (APP) and dam safety engineers already on site.

Further rainfall is expected, which may complicate operations, but authorities remain cautiously optimistic that these interventions could either prevent collapse or reduce the severity of any potential outflow.

Cllr Minnaar has urged residents to rely on verified updates from official sources and avoid spreading unconfirmed messages that could cause unnecessary panic. "Respect all safety warnings and evacuation notices when and where issued," he said.

De Kaap Echo echoes this call. In times of uncertainty, accurate information and calm, responsible communication are essential.