Laos Reservoir Transparency

EDL-Gen (state hydropower company) publishes daily water-level and storage-volume data for its ~10 wholly-owned HPPs via a public website. The Mekong Dam Monitor (Stimson Center / Eyes on Earth) provides satellite-derived weekly storage estimates for a further ~10–15 major Lao dams including Nam Theun 2, Nam Ngum 1 & 2, Nam Ngiep, and Theun Hinboun Expansion. However, Laos had 76+ operational dams as of 2024: the majority are Chinese-built or Thai-financed IPPs with no public operational data. NTPC (Nam Theun 2 Power Company) does not publish reservoir storage volumes on its website despite World Bank conditionality. No national-level government portal aggregates reservoir storage across the sector.

No official Laos government source publishes reservoir data via REST API or open machine-readable file (CSV, JSON, XML). EDL-Gen's Water Availability page is a dynamically rendered HTML dashboard with no download function or documented API. The Mekong Dam Monitor (a third-party US tool) is freely accessible without registration and supports data downloads, but it uses satellite-derived estimates rather than official in-situ data. The MRC Data Portal (portal.mrcmekong.org) uses CKAN and may expose a metadata API, but covers river gauge telemetry — not reservoir storage volumes for Laos. No registration-free, official, machine-readable endpoint for Laos reservoir storage exists.

EDL-Gen publishes daily water-availability data for its ~10 wholly-owned strategic HPPs via a public English-language website. However, of the 76+ operational dams as of 2024, approximately 70 IPP/Chinese-built dams (Xayaburi, Don Sahong, Nam Ou cascade, Nam Theun 2, etc.) are operated under confidential concession agreements with no public storage disclosure. Score lowered from 15 to 12 to apply a conservative discount: the ~70 IPP Chinese-built and concession-managed reservoirs are individually absent from any government publication, and EDL-Gen's coverage is limited to its strategic asset subset. Prior justification (preserved for context): Methodology denominator counts reservoirs with capacity >10 hm³. Laos has approximately 50–80 qualifying reservoirs out of the 76+ operational dams as of 2024, including Nam Ngum 1 (~7,000 Mm³), Nam Theun 2 (~3,500 Mm³), Nam Ngiep, the Nam Ou cascade, Xayaburi and Don Sahong mainstream Mekong dams, plus most large IPP HPPs. EDL-Gen publishes daily water-availability data for its ~10 wholly-owned HPPs via a public English-language website. The Mekong Dam Monitor (third-party, satellite-derived) covers an overlapping ~15 largest dams but is not Lao government coverage. Excluding third-party sources, ~10 of an estimated ~65 qualifying reservoirs have government-published storage data. Coverage = round(100 × 10 / 65) = 15.

No official Lao government source publishes a downloadable multi-year time series of reservoir storage. EDL-Gen has posted occasional water-level snapshots on its website since at least 2018 (Nam Ngum 1 reservoir condition post, August 2018), but these are news articles rather than structured archives. The Mekong Dam Monitor provides weekly satellite-derived storage going back to approximately 2020 for covered dams. Satellite altimetry services (HydroWEB, G-REALM) cover Nam Ngum reservoir from the early 2000s but are external research tools, not government publications. No machine-readable historical archive of national scope exists.

EDL-Gen states that its Water Availability page provides daily information on the status of its ~10 HPPs, and this was confirmed by the Mekong Dam Monitor 2024 Progress Report as a genuine daily public update — a meaningful step for the region. The Mekong Dam Monitor publishes weekly satellite-derived estimates. However, these sources together cover only a fraction of Laos's dams. For a five-week window in 2023, EDL-Gen also shared PDF dam operation reports for more than 60 dams via its Facebook page, but this was not sustained. The vast majority of Laos dams have no regular public update cycle.

The Mekong Dam Monitor publishes its complete methodology in English and Lao, including satellite inputs (Sentinel-1, ALOS DEM), virtual gauge validation (±1 m margin), and volume look-up table construction. This third-party methodology is exemplary. However, EDL-Gen publishes no documentation on how its in-situ water-level and storage measurements are conducted, what instrumentation is used, or how volumes are calculated from level readings. NTPC/Nam Theun 2 similarly publishes no public measurement methodology for reservoir operations. No Lao government body has published a reservoir monitoring standard or data quality protocol.

The EDL-Gen website is available in English (lang=en parameter). The Mekong Dam Monitor is fully English. The MRC Data Portal and its documentation are in English. NTPC's website is in English. The World Bank's Nam Theun 2 project documentation is in English. However, the Lao government's MNRE and MEM portals — the primary domestic authorities — are primarily in Lao script, and there is no English-language national reservoir data portal. The best English-accessible data remains the third-party MDM rather than official Lao government sources.