Not rated — no significant reservoirs
Solomon Islands 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
Solomon Islands Reservoir Transparency
N/AWhy it's not rated
No operational water-supply or hydropower storage reservoirs (Tina River is run-of-river; Gold Ridge is a mine tailings dam).
Where its water comes from
Rivers and groundwater on Guadalcanal (Solomon Water).
Reference source
Solomon Islands Water Authority (SIWA / Solomon Water)
https://www.solomonwater.com.sb/Evaluator notes
The Solomon Islands presents a more complex case than the other structural-zero nations in this group. Guadalcanal has rivers, forested catchments, and genuine hydropower potential — the 15 MW Tina River Hydropower Project (under development as of 2026 with World Bank/MIGA support) will be the country's first large utility-scale renewable project. However, it is a run-of-river scheme with a small diversion weir, not a storage reservoir. The Gold Ridge Mine dam is a tailings structure unrelated to public water supply. The proposed Lungga River Dam for Honiara water supply and flood control is a planning-stage project. Honiara's current water supply comes primarily from Kongulai Springs and Lungga River river intakes managed by Solomon Water (SIWA). No public water-supply reservoir with reported fill levels currently exists in the Solomon Islands. Solomon Water has been actively modernising with ADB funding and publishes project progress reports, but no operational reservoir data is in the public domain. The RTI score reflects the absence of the data publication infrastructure rather than a lack of physical water resources.
Evaluated by Jaime Delgado · 2026-09-15 · Methodology v1.3.0