B2Gold : Tailings Storage Facility Inventory - October 20, 2025 (B2Gold TSF Inventory Oct 2025 Rev A)

This document presents B2Gold Corp.'s updated disclosure of its Tailings Storage Facilities (TSFs) as of October 20, 2025, in alignment with the Church of England's Tailings Inventory framework. The inventory covers five

TSFs across global operations in Mali, Namibia, the Philippines, and Canada, providing detailed insights into their design, operational status, hazard classification, and long-term stewardship.

1	Tailing Storage Facility (TSF) Name		Fekola TSF1 1	Otjikoto TSF 2	Masbate TSF 3	Atlas TSF 4	Goose Echo TF 5
2	Site Name (Location)		Fekola (Mali)	Otjikoto (Namibia)	Masbate (The Philippines)	Masbate (The Philippines)	Goose (Canada)
2a	TSF Centroid Latitude		12°33'06" N	20°00'15" S	12°26'45" N	12°28'38" N	65°32'11" N
2b	TSF Centroid Longitude		11°21'48" W	17°04'50" E	123°23'47" E	123°23'03" E	106°27'19" W
3	Ownership		B2Gold (Mali) 6	B2Gold (EVI) 7	Filminera (Zoom), PGPRC 8	Filminera (Zoom), PGPRC 8	B2Gold (Back River) 9
4	TSF Status		Operating	Operating	Operating	Inactive 10	Operating
5	TSF Start-up	(year)	2017	2014	2009	1980	2025
6	Design Intent Compliance (a)		Yes	Yes	Yes	Unknown 11	Yes
7	Raise Methodology (b)		DS	US 12	DS, CL 13	DS	In-pit
8	Current Maximum Height	(m)	58.7	32.8	67.0	37.5	Not applicable - in-pit facility
9	Current Tailings Volume	(Mm3)	40.0	23.1	81.4	22.80	0.14
10	Planned Tailings Volume in this TSF by October 2030	(Mm3)	41.5 (14)	28.8	108.5	22.80	3.8
11	Most Recent Independent Review (c)	(Month Year)	Oct-2023	Sep-2025	Jul-2024	Jun-2020	To be decided 15
12	Engineering Records Complete	(Yes / No)	Yes	Yes	Yes	Yes 16	Yes
13	Hazard Classification (d)		High A	High 17	Extreme	Extreme	Low 18
14	Classification Guideline (e)		ANCOLD	GISTM	ANCOLD	ANCOLD	CDA
15	Stability ever Questioned (f)	(Yes / No)	No	Yes 19	Yes 20	Yes 21	No
16	Internal Oversight and/or External Support	(Yes / No)	Yes and Yes	Yes and Yes	Yes and Yes	Yes and Yes	Yes and Yes
17	Most Recent Dam Breach Study	(Month, Year)	Sep-2023	Jan-2023	Nov-2023	Jul-2021	Not applicable - in-pit facility
18	Closure Plan in Place / Long Term Monitoring Included (g)	(Yes / No)	Yes and Yes	Yes and Yes	Yes and Yes	Yes and Yes	Yes and Yes
19	Climate Change Effects Considered (h)	(Yes / No)	Yes	Yes	Yes	Yes	Yes
20	Notes (i)		-	-	-	-	-

Column questions and applicable footnotes:

1. "Tailings Facility" Name/identifier. Please identify every tailings storage facility and identify if there are multiple dams (saddle or secondary dams) within that facility.

   1. Fekola facility currently consists of three dam segments joined at approximately right angles to contain tailings within a natural basin.

   2. Otjikoto facility consists of seven dam segments (walls) that form a ring.

   3. Masbate facility consists of multiple saddle dams. Currently dams in place include, Main Dam, Saddle Dam 1&2, Saddle Dam 4, Saddle Dam 7, and Saddle Dam 8. Other segments of saddles have been eliminated as the facility reservoir level increased as they combined into one of the aforementioned dams.

   4. The Atlas facility originally consisted of three separate cells. The supernatant pond was removed, and the surface of the facility was fully capped in early 2023; hence, it now consists of a single cell.

   5. Echo facility is an in-pit tailings storage facility commissioned in June 2025, strategically designed to leverage the natural permafrost conditions of the Nunavut region in Canada.

2. Location.

   2a, 2b, Latitude and Longitude in decimal degrees of the approximate TSF centroid, as obtained from Google Earth Pro.

3. Ownership Please specify: Owned and Operated, Subsidiary, JV, NOJV, as of October 2025

   6. B2Gold owns an 80% interest in Fekola S.A. the Company's Malian exploitation company, the State of Mali holds the remaining 20% interest.

   7. B2Gold Namibia, the holder of Mining License 169 and operator of the Otjikoto Mine is 90% owned, indirectly, by B2Gold and 10% by EVI Mining (Proprietary) Ltd., a Namibian empowerment company.

   8. B2Gold holds its project interest through indirectly-owned subsidiaries. B2Gold has a 40% interest in Filminera and a 100% interest in PGPRC. The remaining 60% interest in Filminera is held by a Philippines-registered company, Zoom Mineral Holdings Inc. ("Zoom") that is owned by a Philippine shareholder.

   9. B2Gold Corp. holds 100% of B2Gold Back River which owns and operates the Goose Mine.

4. Status: Active, Inactive/Care and Maintenance, Closed etc. Closed to mean: a closure plan was developed and approved by the relevant local government agency, and key stakeholders were involved in its development; a closed facility means the noted approved closure plan was fully implemented or the closure plan is in the process of being implemented. A facility that is inactive or under C&M is not considered closed until such time a closure plan has been implemented.

   10. Legacy facility inherited during property acquisition.

5. Date of initial operation.
6. Is the Dam currently operated or closed as per currently approved design?

   (a) Unknown is indicated for legacy TSF that was acquired by B2Gold for which Engineering Records are not complete, and the original design, operation and closure intent is not fully known.

   11. Additional field investigations and design work were completed between 2020 and 2025 and are still ongoing to support the Design Intent Compliance review [refer to note 15 (20) below for more information on the current status of the Atlas TSF].

7. Raising method: Upstream, Centerline, Modified Centreline, Downstream, In-pit, Landform, Other.

   (b) Upstream (US), centreline (CL), modified centreline (MCL), downstream (DS), and/or In-pit methodologies may have been used at any given facility.

   12. Otjikoto facility implements an upstream raise methodology, initial raise slurry deposition was performed by paddocking, in January 2017 the deposition methodology was changed to cycloning.

   13. The Masbate facility predominantly implements a downstream raise methodology, with the exception of stages 10 and 11 of the Main Dam and stage 11 of Saddle Dams 7 and 8 which were constructed as centreline raises.

8. Current Maximum Height
9. Current Tailings Storage Impoundment Volume: (m3 as of October 2025)
10. Planned Tailings Storage Impoundment Volume in 5 years time. (m3 as planned for October 2030)

    14. TSF1 is projected to reach full capacity by Q4 2025 and is currently approaching that limit. Construction of the new facility, TSF2, was completed in May 2025 and will begin receiving tailings once TSF1 is fully utilized. The final tailings volume at TSF1 will be confirmed after deposition has ceased.

11. Date of most recent Independent Expert Review. For this question we take 'Independent' to mean a suitably qualified individual or team, external to the operation, that does not direct the design or construction work for that facility.

    (c) In accordance with B2Gold's tailings management procedure, an independent expert review is conducted at least once every five years

    15. Echo TF was only commissioned in June 2025, and an independent expert review will be conducted later in the facility's lifecycle. It is worth noting that the facility is an in-pit tailings facility with a low consequence classification.

12. Do you have full and complete relevant engineering records including design, construction, operation, maintenance, and/or closure? We take the word "relevant" here to mean that you have all necessary documents to make an informed and substantiated decision on the safety of the dam, be it an old facility, or an acquisition, or legacy site.

    16. While not all engineering records were available at the time of acquiring this legacy TSF, geotechnical investigations conducted in 2020, 2021, and 2024, along with the slope stability assessment and deformation modelling, enabled the completion of the Atlas TSF's engineering records. The site is currently in the process of appointing an Engineer of Record for the facility

13. What is your hazard categorisation of this facility, based on the consequence of failure?

    (d) It is imperative to note that hazard classification is determined based on the consequential impact if a facility were to experience a failure. The listed hazard classifications do not in any way represent a probability of failure, or risk of failure, of a facility.

    17. To meet life-of-mine capacity, the team opted for horizontal expansion by adding a new tailings cell that shares walls with the existing facility, rather than continuing vertical expansion beyond the original dam design height. This approach has reduced the facility's consequence classification from ''Very High'' to ''High''. The consultant is currently updating the dam break analysis to reflect the revised life-of-mine height and finalize the TSF's consequence classification.

    18. This facility is not classified based on physical stability, as it is an in-pit tailings facility. The classification presented in this table is based on environmental consequence, in accordance with CDA (2023)

14. What guideline do you follow for the classification system?

    (e) ANCOLD = Australian National Committee on Large Dams, GISTM = Global Industry Standard on Tailings Management, CDA= Canadian Dam Association

15. Has this facility, at any point in its history, failed to be confirmed or certified as stable, or experienced notable stability concerns, as identified by an independent engineer (even if later certified as stable by the same or a different firm). We note that this will depend on factors including local legislation that are not necessarily tied to best practice. As such, and because remedial action may have been taken, a "Yes" answer may not indicate heightened risk. Stability concerns might include toe seepage, dam movement, overtopping, spillway failure, piping etc. If yes, have appropriately designed and reviewed mitigation actions been implemented? We also note that this question does not bear upon the appropriateness of the criteria, but rather the stewardship levels of the facility or the dam.

    (f) Not being certified/confirmed as stable is assumed to be where a noted deficiency is deemed sufficiently significant to trigger a catastrophic failure -the term deficiency is used in that context herein; for operating facilities, this refers to any identified deficiency for the current life/stage and for a previous life/stage, any deficiency that was not addressed as vetted by independent review; for closed/legacy facilities, this refers to any deficiency identified that reflects the current state of the facility.

    19. The Otjikoto TSF was originally designed using drained shear strength parameters for tailings, in line with industry standards at the time. In 2022, a cone penetration testing (CPT) program was conducted to assess the in-situ behavior of the tailings. The CPT data enabled estimation of undrained shear strength parameters, which were subsequently used to evaluate the slope stability of the TSF dam walls under static, seismic, and post-liquefaction conditions. A stability update completed in 2023 indicated that the majority of TSF wall sections met the minimum required factor of safety (FoS) for both static and earthquake loading. However, one cross section was found to be slightly below the threshold. In response, B2Gold promptly initiated corrective measures by flattening the steep downstream slope of the non-compliant section to match the design profile, thereby improving its FoS and enhancing overall facility stability. To mitigate the risk of flow (static liquefaction) failure at the TSF and accommodate life-of-mine tailings capacity, the team opted for horizontal expansion rather than continuing vertical deposition above the original dam height. This approach involves constructing a new tailings cell that will share walls with the existing facility. Design work is currently underway, targeting completion in Q1 2026, and is supported by an ongoing geotechnical investigation. Moreover, as part of the risk mitigation strategy and long-term closure planning, the team is looking into installing a waste rock blanket to enhance the stability of exposed TSF perimeter walls and improve erosion control. The final size and configuration of the blanket are yet to be determined.

    20. The Masbate facility has been extensively reviewed by various independent consultants over the last five years; areas of investigation included 1) Historic use of lithic-tuff material in embankment construction, a detailed geotechnical drilling investigation was completed which showed that a narrow section in Main Dam stage 9 included lithic tuff, the stability modelling of the material resulted in Factor of Safety values larger then 1.5 which meets closure criteria. 2) Foundation preparation was investigated via geotechnical drilling and confirmed that all unsuitable material was removed. 3) A high phreatic surface was returned in a single piezometer within a saddle dam was investigated and determined that the piezometer was incorrectly drilled through natural ground level and into the groundwater table which was providing a false reading of a high phreatic surface. 4) A peer review of stage 11 pseudo-static stability conditions was questioned due to different assumed values of the tailings stability characteristics. In-situ samples of tailings were retrieved from the beach at various locations and depth to confirm material parameters and eliminate this concern. Moreover, the 2024 independent dam safety review identified no stability concerns with the embankment. Recommendations provided by the independent review have been incorporated into the ongoing geotechnical field investigations and the design process. These investigations, along with advanced numerical modeling, continue to inform and support the design of future dam raises and the eventual closure of the facility.

    21. The mine was abandoned in 1994, and a new owner purchased the property in 1995. In 1997, a tailings management study conducted as part of a feasibility study highlighted stability concerns under seismic conditions and recommended a stabilization buttress. B2Gold has not found any records supporting the implementation of these historic recommendations. In 2020, B2Gold performed an independent third-party risk assessment and geotechnical investigation, yielding critical information for our mitigation plan and closure criteria. The largest cell, Pond ABCD (approximately 85% of the facility by volume), was identified as free draining and not susceptible to flow failure during seismic events. Extensive ground investigation work took place in 2020 and 2021, confirming that tailings within Pond ABCD and Pond F are unlikely to liquefy. Although updated slope stability analyses indicated insufficient embankment stability under recommended earthquake loads, numerical modeling suggests limited deformation in the tailings storage facility (TSF). B2Gold promptly removed surface water from ponds and installed a closure cover over the entire TSF surface area to prevent supernatant accumulation and reduce flow failure risk. Additionally, erosion protection was completed in 2024 to safeguard the toe of the TSF against flooding from the Guinobatan River. Piezometric monitoring in the TSF is ongoing, and a more robust cap may be considered if needed. A 2024 field investigation was conducted to verify in situ tailings conditions post-capping and pond removal. The consultant is currently updating the stability and deformation models to reflect current subsurface conditions. Notably, the facility has remained dormant for over 30 years, and monitoring data during this period has not indicated any stability concerns.

16. Do you have internal/in house engineering specialist oversight of this facility? Or do you have external engineering support for this purpose?
17. Has a formal analysis of the downstream impact on communities, ecosystems and critical infrastructure in the event of catastrophic failure been undertaken and to reflect final conditions? If so, when did this assessment take place? Please answer 'yes' or 'no', and if 'yes', provide a date.
18. Is there a) a closure plan in place for this dam, and b) does it include long term monitoring? Please answer both parts of this question (e.g. Yes and Yes)

    (g) Closure plans are generated from start of design of a facility and are regularly updated throughout the life of the facility. Closure plans begin at a conceptual state and are progressively updated over the life of mine.

19. Have you, or do you plan to assess your tailings facilities against the impact of more regular extreme weather events as a result of climate change, e.g. over the next two years?

    (h) Climate change effects are considered through regular review of extreme weather events records (e.g., event return period and precipitation magnitude). In addition, B2Gold plans to further incorporate climate change risks into our enterprise and site assessment and planning processes, to better adapt to the physical impacts of climate change and to increase the resilience of our operations and business.

20. Any other relevant information and supporting documentation. Please state if you have omitted any other exposure to tailings facilities through any joint ventures you may have.

(i) Information is current as of the date 06 May 2024.