Not rated — no significant reservoirs
Comoros 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
Comoros Reservoir Transparency
N/AWhy it's not rated
No surface water on the main island (Grande Comore) and no impoundments.
Where its water comes from
Rainwater harvesting and marginally fresh coastal groundwater.
Reference source
MAMWE — Ma-Mwe (Société Comorienne des Eaux et Electricité) / Direction Générale de l'Eau
https://earthwise.bgs.ac.uk/index.php/Hydrogeology_of_ComorosEvaluator notes
Comoros sits at the structural floor of the RTI for reasons that differ slightly from other low-scoring countries: there are simply no significant surface reservoirs to monitor. Grande Comore, a volcanic island, is geologically porous and accumulates no surface water, while the smaller islands rely on streams. Water security for the archipelago's approximately 900,000 inhabitants depends on rainwater cisterns, springs, and shallow coastal groundwater — none of which fall within the RTI's reservoir-storage scope. The evaluation nonetheless matters as a reference point: had infrastructure investments produced water-storage reservoirs, Comoros would face serious transparency challenges given the limited institutional capacity of MAMWE and the Direction Générale de l'Eau. UNDP and AfDB climate-resilience projects (2023–2026) are building hydrological data capacity at the local level as a climate adaptation measure, which could improve general water data transparency in coming years even if reservoir-specific RTI metrics remain inapplicable. This score should be revisited if any significant dam or reservoir project materialises.
Evaluated by Jaime Delgado · 2026-09-15 · Methodology v1.3.0