Gabon Reservoir Transparency

SEEG (Société d'Énergie et d'Eau du Gabon) operates the Tchimbélé Dam (650 Mm³ on the Mbé River) and the Kinguélé Dam (29 Mm³, 57 MW) — the two main hydropower assets supplying ~40% of Greater Libreville's electricity for approximately one million inhabitants. SEEG does communicate reservoir level data publicly, but only reactively and in narrative press releases during crisis periods. In 2024–2025, Tchimbélé's level dropped to 515.98 m, well below the critical 517 m threshold and far from the 531 m optimum; SEEG disclosed this in media reports on gabonreview.com. This reactive disclosure, while not a structured open-data publication, demonstrates that SEEG holds and on occasion releases specific level readings.

SEEG has a functional public website (seeg-gabon.com) with sections on water management activities, but no data portal, API, downloadable time series, or structured data feed. The 2024–2025 Tchimbélé level data was communicated via press release narrative and social media (SEEG Twitter/X account), not a machine-readable endpoint.

Capacity-weighted (v1.3.0): ~170/679 Mm³ ≈ 25% (Tchimbélé 650 + Kinguélé 29; SEEG publishes only crisis-driven press notices during shortage events — no structured feed, qualitative signal only). Prior justification (preserved for context): Methodology denominator counts reservoirs with capacity >10 hm³. Gabon has 2 qualifying reservoirs: Tchimbélé (650 Mm³ on the Mbé) and Kinguélé (29 Mm³). Both are operated by SEEG and both receive reactive crisis-level public disclosure (e.g., Tchimbélé level cited at 515.98 m vs. 517 m critical / 531 m optimal during the 2024-25 dry-season crisis). The Kinguélé Aval extension adds capacity but no structured monitoring page exists for any of the three. Coverage = round(100 × 1 / 2) = 50, reflecting that the two qualifying reservoirs receive partial, reactive disclosure rather than systematic publication.

No historical time series of reservoir levels is publicly accessible. The crisis communications from 2024–2025 provide a single snapshot (current level vs. thresholds) but not a time series. Academic work on Mbé River hydrology (e.g., FutureWater report on Gabon, 2017) provides some historical context from external sources, but no national public archive exists.

Updates appear only during supply crises — there is no evidence of a regular (weekly, monthly) bulletin. The SEEG Twitter account and occasional gabonreview.com reports serve as ad-hoc communication channels. This is reactive, not scheduled, disclosure.

SEEG's crisis releases reference specific metric elevation thresholds (515.98 m observed; 517 m critical; 531 m optimal), indicating that a formal monitoring protocol with defined thresholds exists internally. However, the measurement methodology, instrumentation, and data quality procedures are not published. The reference to a 'technicien SEEG' in a government Facebook video suggests professional staff monitoring, without public documentation.

SEEG communicates in French, which is internationally accessible. The SEEG website (seeg-gabon.com) is in French with a structured navigation. Were data ever published in a structured format, it would be accessible to Francophone researchers and the international community. A modest positive score reflects this language advantage.