Emergency efforts to avert a potential disaster at a privately-owned dam near Barberton in Mpumalanga are facing significant challenges, as river inflows continue to impede water-level reduction.
The Department of Water and Sanitation (DWS) on Wednesday confirmed that Senteeko Dam, officially registered as My Own Dam, is at risk of failure due to critical structural damage.
According to the department, the 26-metre-high, medium-sized dam, with a storage capacity of 1.8 million cubic metres, is owned by the Shamile Communal Property Association and serves irrigation purposes in the area under the City of Mbombela Local Municipality.
The department has mobilised a team of dam safety engineers to work alongside the owner’s previously appointed Approved Professional Person (App) to assess the damage and monitor the situation, according to DWS spokesperson Wisane Mavasa.
“The dam is an earthfall embarkment dam with a concrete spillway,” Mavasa said.
Critical spillway damage threatens stability
Technical assessments conducted by the department’s dam safety specialists have revealed alarming deterioration of the dam’s spillway system.
The specialists have found that erosion beneath the spillway channel continues to worsen.
“Undercutting of the spillway channel is continuing, eroding and posing a threat to the stability of the structure,” Mavasa explained.
She added that the spillway channel slab is in a precarious state, now slightly suspended or supported on only one side above the eroded foundation.
However, the main dam structure appears to remain intact for now, Mavasa noted.
“There is currently no overtopping of the dam wall, and no excessive seepage has been observed on the earthfill embankment wall,” she said.
WATCH: The state of the dam wall
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Water level reduction proves difficult
Despite emergency protocols being activated, efforts to lower the dam’s water level are proving frustratingly slow.
The dam’s outlet valve has been fully opened in accordance with operating rules, but persistent upstream inflows are hampering progress.
“Due to increased inflows from the Die Kaap River, which is a tributary to the dam, the lowering of the dam water level has been minimal,” Mavasa stated.
This ongoing challenge has necessitated more drastic intervention measures.
The dam owner is expected to commence excavations of a side-channel spillway under the supervision of the App.
“This side-channel spillway is intended to lower the water level in the dam, thereby reducing undercutting of the spillway channel and preventing catastrophic failure of the dam,” Mavasa explained.
She added that the emergency excavation work is anticipated to proceed, regardless of weather conditions.
Communities at risk as evacuation measures implemented
Authorities have identified vulnerable areas and initiated emergency response protocols for communities in the potential flood path.
The most at-risk zones have been mapped. “The areas most likely to be affected have been identified as those in close proximity to the dam, particularly the Barberton Valley,” Mavasa stated.
Coordination between various authorities is underway to ensure public safety.
“Relevant communications, warnings, and evacuation processes are being implemented by the relevant authorities,” Mavasa confirmed.
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River conditions show improvement
There are encouraging signs regarding water conditions in the upper catchment.
According to the department, the Inkomati-Usuthu Catchment Management Agency has been monitoring river flows and has observed a positive trend over the past few days.
“Observations of the upper reaches of the Die Kaap River by the IUCMA indicate that river flows have decreased since 19 January 2026,” Mavasa reported.
Downstream conditions are also being closely watched, particularly regarding potential transboundary impacts.
The Crocodile River, about 60 kilometres from Senteeko Dam, is currently flowing at normal recent peak levels.
Should current intervention measures fail to prevent collapse, the consequences for neighbouring countries would likely be limited, Mavasa explained.
Any additional flows resulting from an unforeseen dam failure are expected to have minimal impact on transboundary flows to Mozambique, which are currently elevated due to the recent flooding conditions,” she said.
Public urged to heed safety warnings
The department issued stern warnings to communities in the affected areas.
“The Department of Water and Sanitation takes dam safety seriously and urges communities to comply with all evacuation orders issued along the Die Kaap River,” Mavasa emphasised.
The public is being advised to avoid low-water bridges, unnecessary travel, and activities near rivers during this critical period.
In an era of rapid information spread through social media, responsible sharing of information is essential to prevent panic and misinformation that could complicate emergency response efforts.
“The department urges the public to share verified information responsibly,” Mavasa stressed.
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