Minister Pemmy Majodina: Release of preliminary investigation into failure of 3 dams on Riverlands farm

Deputy Minister Sello Seitlholo
MEC for Local Government, Anton Bredell
MEC for Infrastructure, Tertuis Simmers
Mayor of the West Coast District Municipality, Roelof Strydom
Mayor of Swartland Local Municipality, Harold Cleophas

On the 8th of August 2024, my team informed me of a tragic incident that befell the community of Riverlands in the Swartland Local Municipality in the early hours of the morning. At the time, reports stated that three dams located on Dassenberg Farm breached, resulting in flooding that caused severe property and infrastructure damage to the affected area, leading to hundreds of people being provided with humanitarian assistance. This farm lies within the jurisdiction of the City of Cape Town. However, the flooding caused by the failure of these dams affected the downstream community of Riverlands, in the Swartland Municipal area.

These dams had no names or their names were not known. We came to refer to them as dam one, two and three starting from the downstream dam. All of them did not have adequate spillways and initial information suggested that dam three filled beyond the safe level, resulting in overtopping due to high rainfall and associated run off, causing dams two and one to fail in series.

On the same day, the City of Cape Town appointed a dam engineer to assess the extent of the failure of the dams, who then assessed a fourth dam - dam four - on the upper stream. At this point it was discovered that dam four also had insufficient spillway to accommodate the incoming flood. The City of Cape Town, through the dam engineer, requested permission to construct a spillway which the department granted. The spillway was then constructed by the City of Cape Town on Saturday, 10 August 2024.

On Sunday, 11 August 2024, I, together with MEC for Local Government, Anton Bredell and Mayor of Swartland Local Municipality, Cllr Harold Cleophas, visited the disaster-stricken area to see for ourselves and get a brief from the teams working on site. Consequently, I instituted an investigation into what caused the failure of the three dams, to determine ownership of the dams, verify if the dams complied with dam safety regulatory requirements and if there was proper authorization from my department. I gave the team seven days to complete the investigation.

On the 12th of August 2024 our dam safety team began with the investigation in Riverlands. On arrival, our team discovered that dam four, which is the highest dam in the valley, was on the verge of failure. To reduce the risk of potential failure, our Dam Safey Office took the decision to partially empty the dam to protect the lives of the community members living downstream. Furthermore, the team discovered another dam downstream of dam one, which we call dam zero.

Our team spent the first few days trying to prevent further damage, thus delaying the investigation. Additional resources were mobilized from our team working on the Clanwilliam Dam project to alleviate what could have been disastrous. The investigating team requested a seven-day extension to complete its work, which I granted. On Monday 26 August 2024, they handed a preliminary report to me.

History of ownership

In terms of our investigations, the oldest dam is dam three, which was constructed between 1960 and 1966. Between 1966 and 1992, dam one and two were constructed. Dam four, which is the largest in the property, was built between 2000 and 2005. It appears that dam zero was constructed at the same time as dam four.

When dams three to one were constructed, the owner of the property was Dassenberg Plaas Pty Ltd. The farm was then sold to Agrico Machinery Pty (Ltd), which proceeded to construct dams four and zero. The property was acquired by National Government in 2019. The Department of Agriculture, Land Reform Rural and Development (DALRRD) became the custodian of the property on behalf of government. With the reconfiguration of departments, the property currently belongs to the Department of Land Reform and Rural Development. The Dassenberg Farm is currently leased by the Department of Rural Development and Land Reform to Mazibuyinkomo Primary Agricultural Co-Operative.

Responsibility of the owner

In terms of the National Water Act (NWA), the responsibility for the safety of dams rests with the dam owner. In this instance the owner is currently the Department of Land Reform and Rural Development, which is the custodian of the property on behalf of government.

The owner of the dams had a legal obligation to register the dams that meet the requirements to be classified as dams with a safety risk within 120 days as required by Section 120(2) of NWA. This obligation extends to all other previous owners for failure to register the dams as required.

The Department of Land Reform and Rural Development failed to conduct due diligence to ascertain whether the five dams in the property are compliant with the National Water Act and whether the dams are registered with the relevant authority.

It must be noted that the dams were not constructed by government. The property was acquired together with the dams. However, the current owner was required to do a due diligence and ensure that the dams comply with all the relevant legislation.

The previous owners who constructed the dams were required to obtain a Dam Safety licence to construct a dam before commencing with construction. There is no record of any permit/licence being issued by DWS.

The dams were not registered with the Dam Safety Office as per the NWA requirement by the owner.

Cause of failure

Our investigation shows that Dam three failed as a result of piping failure (internal erosion) which compromised the stability of the dam wall significantly. The failure of Dam three led to a cascading failure effect on Dam two, Dam one, and Dam zero due to overtopping failures since Dam three's capacity was larger than the capacities of the dams downstream.

All the dams had no prominent spillway structures and therefore they did not meet the dam safety standards and standard engineering criteria. The failure of the dams could have been avoided if the dams had been registered with DWS so that they could be properly regulated, and if mandatory dam safety evaluations had been conducted by an experienced dam engineer.

Findings

When the first three dams were constructed, the Water Act (Act 54 of 1956) was applicable. In terms of this Act, the requirement for a licence to construct a dam was in place. There is no record of a licence having been issued for the construction of any of the dams on the property. The owners of the Dassenberg Farm (i.e Dassenberg Plaas Pty Ltd), appear to have constructed these dams without first obtaining a licence/permit in terms of the then Water Act.

When the farm was sold to the Agrico Machinery Pty (Ltd), the new owner proceeded to construct the fourth dam, also without a licence to construct as required by the National Water Act of 1998.

The investigation has established that Dams one to four meet the requirements to be classified as dams with a safety risk since they have vertical wall heights of more than 5,0 m and can contain more than 50 000 m3 of water as defined in Section 117 of the NWA. Dam zero is too small and therefore does not fall in this category. None of the owners (both the previous and the current owners) complied with s120 of the NWA to register the dams with a safety risk.

Further, the investigation has established that the design or construction of the Dassenberg Farm dams are not in accordance with the latest and best practices in dam engineering. This could be because of the age of the dams and no inspections having been conducted to ascertain if the dams meet the relevant dam engineering standards.

The dams were not equipped with sufficient spillways to accommodate foreseeable floods. Had this been identified earlier, DWS would have issued an instruction to the owner to ensure that these dams have adequate flood handling capacity.

Due to the historic existence of the dams on the Dassenberg Farm, which precedes the National Water Act of 1998, no licence in terms of the NWA was issued, and there is no record a license being issued in terms of the 1956 Water Act.

Way forward

The department will take action against the owner of the dams for non-compliance with the Act and associated regulations. The action will include relief for financial compensation for damage to infrastructure. Criminal investigations are ongoing and will focus on current and past owners that constructed and operated the dam in non-compliance with water use authorisation and dam safety requirements. Action may also be considered to obtain financial compensation for damage to infrastructure.

The Department of Land Reform and Rural Development must present a rehabilitation plan for the areas affected by the failure of the Dassenberg Farm dams and implement it in accordance with applicable legislation (i.e National Water Act and National Environmental Management Act). The Department of Land Reform and Rural Development is required to engage the Swartland Local Municipality in an effort to make a determination on the extent of damages caused by the failure of the Dassenberg Farm dams.

Should the Department of Land Reform and Rural Development decide to rebuild the dams, it must apply to DWS for a water-use license and a dam safety license.

The Department of Land Reform and Rural Development is required to conduct an audit of all the properties where dams have been constructed and apply for classification and registration of all dams that meet the definition in terms of Section 117(c) of NWA, to avoid a recurrence of the disaster that has befallen the community of Riverlands and Chatsworth in the Swartland Local Municipality.

The Swartland Local Municipality should conduct a stormwater management assessment to investigate the current and future impact that the Swart River will have on the residents of the town of Riverlands, in the absence of any flood retention which was provided by the Farm Dassenberg dams.

DWS will publish a notice in the government gazette, to call upon all owners of dams that meet the requirements to be classified as dams with a safety risk to register the dams and comply with any other requirements or directives that may be issued to ensure the safety of the dams in the interest of public safety.

The Dam Owner must inform DWS whether they intend to repair the dams or to decommission the dams. An APP will be required to design and apply for the relevant dam safety license (for both repair and decommission).

Media enquiries:
DWS Head of Communication, Dr Mandla Mathebula
Cell: 083 235 8675

Mr Andile Tshona
Cell: 073 566 3345

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