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June 2025
Coordinates: Lat -19.974367°, Long -43.830101°
Guidance Note
Refer to our guidance note.
Description and Lifecycle Design
The Cocuruto TSF is a compacted-soil structure constructed with silty and clay soils. Constructed in two stages, the current crest elevation is at 806.0 mamsl, with a maximum height of 41m and a crest length of about 300m. The dam has an internal drain system composed of a chimney drain combined with a blanket drain. The drainage system is located along the lower third of the dam section.
- 1979: Initial Embankment Design -Elevation 804.00 mamsl.
- 2003: Final wall raise – Elevation 806.00 mamsl.
In parallel with the TSF wall raise in March 2003 the detailed design and construction for a bell-mouth spillway to control excess water flow within the structure was carried out. In 2014, the detailed design of a surface spillway was developed and in 2015, a new reinforced concrete surface spillway was constructed. In January 2016, the detailed design for the decommissioning of the bell-mouth spillway was prepared and in 2017, the old bell-mouth spillway was sealed and decommissioned. Further spillway modifications were carried out at the Cocuruto TSF in 2023 in order to cater for the Probable Maximum Flood event as required by the legislation.
The Cocuruto TSF is currently used to control site water as tailings deposition was stopped in 1987. Tailings were deposited in the TSF up to an elevation of about 802mamsl. All the site surface water eventually reaches the Cocuruto TSF but most of the water flowing to the dam is redirected via the spillway channel for discharge to the receiving environment. The design for decharacterisation is under development and the concept is to completely drain the reservoir and cover the existing tailings.
With the objective of initiating the decharacterisation process of the dam, the need to implement structural modifications was identified, including the execution of the spillway modification project, to comply with the required return periods for the Probable Maximum Precipitation (PMP) event. In 2024, the construction works were completed, including the closure of the former spillway channel and the regrading of the upstream embankment. This regrading aimed to ensure the separation of the reservoir from the upstream slope of the dam, as a measure to maintain the structural safety and stability of the facility.
Also in 2024, the construction of the downstream inverted drain was completed, with the purpose of protecting the lower portion of the dam in the event of a rise in the phreatic surface during the rainy season, thereby contributing to the maintenance of the safety factor. In the same year, the “As-Is” update of the dam was completed.
Cocuruto General Information
| Facility Name | Cocuruto TSF |
| Start of Operation | 1983 |
| Construction Method | Compacted Downstream Earth Wall |
| Current Deposition Method | Run-off Collection Facility |
| Storage Volume | 4.04Mm3 |
| Design/License Capacity – Volume/Tonnage | 4.04Mm3 |
| Crest Elevation | 806 mamsl |
| Spillway Elevation | 802.5 mamsl |
| Maximum Height | 41m |
| Outer Wall Profile | 1V:2,2H |
Consequence Classification
| TSF GISTM Classification | Extreme |
Risk Assessment
AngloGold Ashanti’s comprehensive risk management system uses designs and controls to eliminate risks and where there are remaining risks, these are mitigated such that the residual risk is a As Low as Reasonably Practicable (ALARP).
Risk assessments are conducted by a multi-disciplinary team in collaboration with the Engineer of Record (EoR) for each facility in line with nationally or internationally accepted best practices. The risk assessment report provides a summary of the key details of the structure, including site investigations, geotechnical parameters, foundation conditions, embankment properties, drainage system details, spillway details, monitoring criteria, and the tailings disposal plan. It also details the risk-analyses methodology (using the qualitative bowtie method), potential failure modes along with their susceptibility and consequences, and the control and mitigation measures.
In the risk analysis conducted in 2023, 11 risks were mapped that could in theory lead to a reduction in the dam’s structural performance, of which two risks were classified in the ALARP (manageable) tolerability range and the others as acceptable. For the two risks in the ALARP (manageable) range, action plans have been developed to, where possible, further reduce these risks to the acceptable range. In addition, actions were recommended for acceptable risks and general recommendations to be applied in the operation and maintenance of the TSF. All these action plans aim to reduce the probability of possible risks, as well as minimize possible impacts resulting from occurrences in the structure.
Impact Assessment
The impact of a potential flow failure has been assessed considering the impact to human health and life, the environment, social and cultural impacts, as well as the infrastructure and economic impacts. These potential impacts have been used to inform the TSF Classification and the risk assessment consequence definition and the mitigation measures to be implemented.
The impact zone covers a distance of 47.5km downstream of the Cocuruto TSF.
The municipalities and areas affected by the impact zone and the main social information of the potential floodplain in the event of the rupture of the Cocuruto TSF is shown in the tables below.
Areas affected by Impact Zone
Cocuruto TSF
| Municipalities in ZAS | Nova Lima, Raposos |
| Municipalities in ZSS | Raposos (MG), Sabará (MG), Belo Horizonte (MG), Santa Luzia (MG) & Lagoa Santa (MG) |
| Main Watercourses Impacted | Rio das Velhas, Córrego da Mina (Queiroz), Ribeirão Sabará, Ribeirão Arrudas, Ribeirão da Prata, Córrego Malheiros, Ribeirão Baronesa, Ribeirão da Mata, Rio Taquaraçu |
| Watersheds | Rio das Velhas |
| Areas with Potential for Interference | Private properties, road infrastructure (MG-030, AMG-150, MG 437, MG-262, BR-381, AMG-145 and MG-020), streets, bridges, in addition to commercial and healthcare establishments, schools, inns, police stations, museums and historical and heritage sites in the district of Honório Bicalho in Nova Lima (MG), and the centres of urban areas of Raposos (MG), Sabará (MG) and Santa Luzia (MG). |
Summary of the socio-territorial characterization of the impact zone
| Type of Property | Quantity |
|---|---|
| Registered properties | 739 |
| Residences | 536 |
| Building | 135 |
| Economic activity | 43 |
| Entities and public agencies | 25 |
| Total Population in ZAS | 2,498 |
| Population with mobility difficulties | 887 |
| Population with Special Needs | 238 |
| Number of Sensitive buildings in ZAS | 30 |
Performance Reviews
AngloGold Ashanti has a comprehensive Tailings Review System which incorporates reviews from multiple levels and internal and external parties. All AngloGold Ashanti TSFs are subject to the following reviews:
- RTFE Performance Reviews – monthly inspections
- EoR Inspections – Monthly, with two safety declarations submitted to the Brazilian National Mining Agency (ANM) in March and September of each year.
- Independent Review of the Emergency Response and Preparedness Plan (EPRP) – Annually
- ITRB Review – Annually
- AngloGold Ashanti Corporate Review – Annually
- Dam Safety Review (RPSB)– Typically every three years or when change TSF
| Reviews | Most Recent Review | Next Planned Review |
|---|---|---|
| EoR | May 2025 | Monthly – 2025 |
| ITRB | October 2024 | October 2025 |
| DSR | November 2024 | October 2025 |
AngloGold Ashanti has adopted the following ranking system for independent reviews:
Priority 1 – A dam safety issue considered immediately dangerous to life, health or the environment, or presents a significant risk of regulatory enforcement. Requires immediate action and to be completed as soon as practically possible but certainly within 2 months
Priority 2 – If not corrected, a concern that could result in a dam safety issue leading to injury, health impact or discontinuity of operations. Requires immediate planning and completion by a date and specified by operations but as a minimum within 5-6 months
Priority 3 – Single occurrence of deficiency or non-conformance that alone would not be expected to result in dam safety issues, discontinuity of operations or regulatory intervention. Requires that measures be taken no later than a date that would prevent escalation, but no later than one year
Priority 4 – A recommendation based on good practice, improvement, or risk reduction. Recommendation towards best practices and mitigating risk associated.
No Priority 1 recommendations have been issued by the ITRB for the Cocuruto TSF.
Environmental and Social
Environment and Social monitoring programmes form part of AngloGold Ashanti’s Health, Safety, Environment (ISO14001) and Social Communities (HSEC) management systems, which act to fulfil the environmental social management system requirements under the GISTM. These environment and social monitoring programmes are comprehensively reviewed, and mitigation measures implemented as and where required. Further information on of our environment and social monitoring programmes, and performance results can be found in AngloGold Ashanti’s Sustainability Reports.
There is potential for ground water seepage from TSFs and ground water conditions around all our TSFs are regularly monitored. Where groundwater impact plumes exist, their migration is modelled and managed, as necessary to avoid interaction(s) with potential receptors.
An easily accessible and effective grievance mechanism has been implemented so that any formal complaints can be submitted by stakeholders and resolved.
Emergency Response and Preparedness
Emergency preparedness and response planning (EPRP) relies on an emergency notification system that consists of remote stations equipped with sirens that are linked to the control room at the Queiroz plant, which scans tiltmeters located on the dam face. Manual activation of the sirens is available locally as redundancy. Mobile sirens are also installed on emergency vehicles that are assigned to predefined emergency routes as an additional notification measure.
The latest dam breach study was conducted in May 2022, and an EPRP training exercise is documented as having been undertaken in 2025, which involved members of the community. Training exercises have included military civil organizations (police, fire) for various communities.
The escape routes and meeting points are sign posted. These were developed based on the zone of influence, in which a maximum walking distance of 1,000m was considered sufficient to allow a quick and safe route to meeting points. The meeting point signage has information such as telephone numbers of emergency agencies, safety recommendations for the population, among other self-preservation information.
A copy of the Cocuruto TSF EPRP can be downloaded on the following link: BARRAGEM COCURUTO – AngloGold Ashanti Brasil
Financial Capacity
AngloGold Ashanti confirms it has adequate financial capacity to cover the agreed share of estimated costs of planned closure, early closure, reclamation, and post-closure monitoring and maintenance of the Cocuruto TSF and its appurtenant structures.
Guidance Note
Certain statements contained in this document, other than statements of historical fact, including, without limitation, those concerning the economic outlook for the gold mining industry, expectations regarding gold prices, production, total cash costs, all-in sustaining costs, cost savings and other operating results, return on equity, productivity improvements, growth prospects and outlook of AngloGold Ashanti’s operations, individually or in the aggregate, including the achievement of project milestones, commencement and completion of commercial operations of certain of AngloGold Ashanti’s exploration and production projects and the completion of acquisitions, dispositions or joint venture transactions, AngloGold Ashanti’s liquidity and capital resources and capital expenditures, the consequences of the COVID-19 pandemic and the outcome and consequences of any potential or pending litigation or regulatory proceedings or environmental, health and safety issues, are forward-looking statements regarding AngloGold Ashanti’s financial reports, operations, economic performance and financial condition.
These forward-looking statements or forecasts are not based on historical facts, but rather reflect our current beliefs and expectations concerning future events and generally may be identified by the use of forward-looking words, phrases and expressions such as “believe”, “expect”, “aim”, “anticipate”, “intend”, “foresee”, “forecast”, “predict”, “project”, “estimate”, “likely”, “may”, “might”, “could”, “should”, “would”, “seek”, “plan”, “scheduled”, “possible”, “continue”, “potential”, “outlook”, “target” or other similar words, phrases, and expressions; provided that the absence thereof does not mean that a statement is not forward-looking. Similarly, statements that describe our objectives, plans or goals are or may be forward-looking statements.
These forward-looking statements or forecasts involve known and unknown risks, uncertainties and other factors that may cause AngloGold Ashanti’s actual results, performance, actions or achievements to differ materially from the anticipated results, performance, actions or achievements expressed or implied in these forward-looking statements. Although AngloGold Ashanti believes that the expectations reflected in such forward-looking statements and forecasts are reasonable, no assurance can be given that such expectations will prove to have been correct.
Accordingly, results, performance, actions or achievements could differ materially from those set out in the forward-looking statements as a result of, among other factors, changes in economic, social, political and market conditions, including related to inflation or international conflicts, the success of business and operating initiatives, changes in the regulatory environment and other government actions, including environmental approvals, fluctuations in gold prices and exchange rates, the outcome of pending or future litigation proceedings, any supply chain disruptions, any public health crises, pandemics or epidemics (including the COVID-19 pandemic), the failure to maintain effective internal control over financial reporting or effective disclosure controls and procedures, the inability to remediate one or more material weaknesses, or the discovery of additional material weaknesses, in the Company’s internal control over financial reporting, and other business and operational risks and challenges and other factors, including mining accidents.
For a discussion of such risk factors, refer to AngloGold Ashanti’s annual report on Form 20-F for the financial year ended 31 December 2024 filed with the United States Securities and Exchange Commission (SEC). These factors are not necessarily all of the important factors that could cause AngloGold Ashanti’s actual results, performance, actions or achievements to differ materially from those expressed in any forward-looking statements. Other unknown or unpredictable factors could also have material adverse effects on AngloGold Ashanti’s future results, performance, actions or achievements. Consequently, readers are cautioned not to place undue reliance on forward-looking statements.
AngloGold Ashanti undertakes no obligation to update publicly or release any revisions to these forward-looking statements to reflect events or circumstances after the date hereof or to reflect the occurrence of unanticipated events, except to the extent required by applicable law. All subsequent written or oral forward-looking statements attributable to AngloGold Ashanti or any person acting on its behalf are qualified by the cautionary statements herein.