Benin Reservoir Transparency

No current reservoir storage volume is publicly accessible anywhere in Benin's official digital infrastructure. The CEB publishes annual charts for Nangbéto (the country's dominant hydraulic asset) but these are embedded PNG images showing historical production statistics — not operational storage levels. DGEau's hydrological annals page (eaubenin.bj) returns HTTP 403, and the water resources portal (ressources-eau.gouv.bj) contains no reservoir storage section. SBEE and SONEB are distribution entities with no hydrological data function. Benin's open data portal (data.gouv.bj) was unreachable during evaluation. The absence of any current-storage publication for Nangbéto — the largest single reservoir — drives this score to near-zero.

No REST API, no open data format, and no machine-readable dataset was found for any Beninese reservoir. The CEB statistics page presents data exclusively as embedded PNG chart images (observed for 2021 data). DGEau's older website returns 403 on key pages and offers no data downloads. The new DG-Eau portal (ressources-eau.gouv.bj) is informational only. ABN's Niger-HYCOS portal covers river flow at Malanville (Benin) but does not include reservoir storage. No registration-gated portal was identified either, meaning the barrier is not registration but total absence of structured data.

Capacity-weighted (v1.3.0): Nangbéto reservoir (1,715 Mm³, shared with Togo and operated by CEB) dominates the national hydropower denominator and receives partial operational data coverage via CEB's annual PNG production charts (multi-year publication lag). However, smaller agricultural and irrigation reservoirs across Benin remain absent from any public reporting, and DGEau's hydrological annals are inaccessible (HTTP 403). Score lowered from 80 to 70 to account for the absence of smaller agricultural facilities not captured by the CEB-shared dominant reservoir, and to apply a conservative discount on the partial/lagged nature of CEB's disclosure. Prior justification (preserved for context): Methodology denominator counts reservoirs with capacity >10 hm³. Benin has 1 qualifying reservoir as co-owner: Nangbéto (1,715 Mm³, jointly operated with Togo by CEB). Secondary SONEB drinking-water storage tanks (Djougou, Savalou, Parakou, Natitingou) are sub-Mm³ and well below threshold. Nangbéto receives partial public coverage via CEB's annual PNG production charts (multi-year publication lag), but no current storage level data is published, and DGEau's hydrological annals are inaccessible (HTTP 403). Coverage = round(100 × 0.5 / 1) = 50, reflecting that the country's one qualifying reservoir has degraded/lagged public data rather than no data at all.

Academic literature (e.g., flood studies on the Mono River) confirms that DGEau and CEB hold historical flow and water-level records for Nangbéto spanning at least 1987–2019, and that these were shared with researchers on request. However, no machine-readable historical time series is publicly downloadable from any official source. DGEau's hydrological annals page is inaccessible (HTTP 403). The ABN Niger-HYCOS portal provides some river discharge data for Beninese stations but not reservoir storage. Score reflects the existence of records in institutional possession rather than any public archive.

The only identified public update mechanism is CEB's annual statistics page, which published charts for 2021 at time of evaluation — a roughly five-year lag. No monthly, seasonal, or real-time data publication was found for any reservoir. DGEau has no public update schedule. There is no evidence of a bulletin, dashboard, or automated data feed for Beninese reservoir storage. ABN publishes annual hydrological balance bulletins for the Niger Basin but these contain river-flow aggregates, not Beninese reservoir volumes.

No public documentation of measurement standards, sensor networks, or data-quality protocols for reservoir monitoring was identified. CEB's website describes Nangbéto's engineering specifications (nominal level 144 m IGN, total capacity 1,715 Mm³, usable 1,465 Mm³) but does not explain how current storage is measured, how often, or with what accuracy. DGEau has not published a hydrometric network description online. The 2013 SDI needs assessment for Benin confirmed that different water-sector organisations maintain siloed, offline databases with no shared standards — a situation not demonstrably improved by 2026.

All official sources — cebnet.org, eaubenin.bj, ressources-eau.gouv.bj, eau-mines.gouv.bj, soneb.bj — operate exclusively in French. No English-language interface, translated summary, or bilingual data label was found on any national government or operator website. While French is the official language of Benin, the RTI language_usability dimension penalises the absence of English accessibility. The baseline 10 points reflects that French is itself a widely-used international language and the portals are at least internally consistent in their language use.