Not rated — no significant reservoirs
Barbados is set aside from the ranking rather than graded. Having no significant reservoir storage is a geographic fact, not a transparency failure — so assigning an “F” would be misleading.
H1 2026 Evaluation
Barbados Reservoir Transparency
N/AWhy it's not rated
No surface reservoirs: coralline-limestone karst, all rivers ephemeral.
Where its water comes from
Over 90% from groundwater wells (limestone aquifer), the remainder from desalination.
Reference source
BWA — Barbados Water Authority
https://barbadoswaterauthority.comEvaluator notes
Barbados is a pure structural case: there are no surface reservoirs on the island, and none are feasible given its geology. The island sits atop a flat Pleistocene coral limestone cap that is highly porous; all surface water percolates rapidly into the underlying karst aquifer system, and no perennial rivers exist to impound. The Barbados Water Authority draws from 22 well and spring sources and 8 boreholes; approximately 10% of supply now comes from desalination, a share that is rising under the USD 110 million IDB/GCF-financed South Coast Climate Resilience project. The 'reservoir' terminology appearing in BWA infrastructure documentation refers exclusively to service-storage distribution tanks. The RTI framework is not applicable in any meaningful sense to Barbados for surface water: there is nothing to measure and no score in any dimension other than language_usability can be greater than zero. The country is not penalised for the absence of data that cannot physically exist; the language_usability credit reflects the fact that, should Barbados ever develop relevant water infrastructure, its English-language governance ecosystem would facilitate disclosure.
Evaluated by Jaime Delgado · 2026-09-15 · Methodology v1.3.0