H1 2026 Evaluation
Bhutan Reservoir Transparency
F4Opaque — Ranked #122 out of 167 countries
weight 30%
weight 20%
weight 15%
weight 13%
weight 10%
weight 8%
weight 5%
Primary source evaluated
Dimension breakdown
Data Availability
20% of total score
Coverage is 0 (no national reservoirs >10 hm³ with public data). Quality dimensions for the COVERED subset are therefore 0 by definition. Original notes preserved below: No Bhutanese government agency publishes current reservoir storage volume online. DGPC (drukgreen.bt) operates the major hydropower plants but publishes no water level or storage data. BPC (bpc.bt) offers only customer billing portals and outage information. BPSO (bpso.bt) publishes aggregate daily generation (MWh) and export figures, but no plant-level inflow or reservoir data. NCHM collects hydrological data at 22 principal and 45 automatic stations but disseminates it only via formal paid request — no self-service viewer exists. Punatsangchhu-II reservoir filling commenced February 2024; no public monitoring portal was announced.
Technical Accessibility
15% of total score
Coverage is 0 (no national reservoirs >10 hm³ with public data). Quality dimensions for the COVERED subset are therefore 0 by definition. Original notes preserved below: No REST API, no open-format data downloads, and no public data portal for reservoir or river water data exists. NCHM's website lists a 'Hydro-met Data Request' service implying data is available only by contacting the agency directly. The Bhutan Data Sharing Platform (data.gov.bt) hosts statistical indicators but no hydrological or hydropower datasets were found. BPSO's daily energy page provides HTML-embedded generation totals but no structured download formats or reservoir-specific data.
Coverage
30% of total score
Methodology v1.3.0 (capacity-weighted). Bhutan's hydropower fleet (Tala 1,020 MW, Chukha 336 MW, Mangdechhu 720 MW, Basochhu 64 MW, Punatsangchhu-II) is overwhelmingly run-of-river with negligible storage: Tala 3.2 hm³, Kurichhu 1 hm³, Punatsangchhu-II 7 hm³ — all below the 10 hm³ analytical threshold. Total qualifying national reservoir capacity is 0 hm³. Coverage = round(100 × 0 / 0) = 0 by structural convention.
Historical Depth
13% of total score
Coverage is 0 (no national reservoirs >10 hm³ with public data). Quality dimensions for the COVERED subset are therefore 0 by definition. Original notes preserved below: NCHM maintains internal hydrological records dating to at least the 1990s across its station network, but these are not publicly downloadable. The NCHM Hydromet Roadmap 2024–2034 acknowledges the need for 'reliable data management systems' as an aspirational goal, confirming that systematic public dissemination does not yet exist. The HEROES weather dataset published via ICIMOD covers only 2015–2020 and is limited to meteorological (not hydrological) variables from 14 school stations. No machine-readable historical time-series for reservoir or river levels is publicly accessible.
Update Frequency
10% of total score
Coverage is 0 (no national reservoirs >10 hm³ with public data). Quality dimensions for the COVERED subset are therefore 0 by definition. Original notes preserved below: No routine publication schedule exists for reservoir or water level data. BPSO publishes daily aggregate electricity generation and export figures, but these are energy (MWh) not hydrology metrics. No weekly, monthly, or annual reservoir storage bulletin is issued by any Bhutanese agency. The MoENR publishes the Bhutan Energy Data Directory (last edition 2022) with annual generation statistics in PDF form, but it contains no reservoir storage time-series.
Methodological Transparency
8% of total score
Coverage is 0 (no national reservoirs >10 hm³ with public data). Quality dimensions for the COVERED subset are therefore 0 by definition. Original notes preserved below: NCHM has published basin-level catchment summary documents (e.g., Wangchu Basin catchment information) and the Bhutan State of the Climate 2017 report, indicating some scientific documentation capacity. The GLOF Early Warning System SOP is publicly available and describes station measurement protocols. However, no methodology for reservoir storage measurement, discharge computation, or data quality control at hydropower plants has been published by DGPC, BPC, or MoENR. The Hydromet Roadmap 2024–2034 is aspirational and does not describe current operational practices.
Language and Usability
5% of total score
English is Bhutan's official language of administration, government, and higher education. All official websites — NCHM, DGPC, BPC, BPSO, MoENR — operate entirely in English. Published reports (Energy Data Directory, State of the Climate, basin documents, GLOF SOP) are in English. The language barrier is effectively absent: any data that exists or may become available will be in English by default. The score is capped below 90 because the absence of substantive data limits the practical utility of language accessibility.
Evaluator notes
Bhutan is a hydropower-dominant economy — approximately 99% of electricity generation is hydroelectric — yet reservoir data transparency is near-zero. The sector is almost entirely run-of-river: Tala (1,020 MW), Chukha (336 MW), Mangdechhu (720 MW), and Basochhu (64 MW) have negligible storage and are operated as flow-through facilities. The only meaningful storage reservoirs are Kurichhu (1 MCM) and Punatsangchhu-II (7 MCM, commissioned 2024). None of these facilities publish water level or storage volume data. DGPC operates the majority of generation capacity but provides no operational hydrology data on its website. BPSO publishes daily aggregate MWh generation and Indian export volumes, which is useful for energy monitoring but wholly inadequate for water resource transparency. NCHM operates an extensive hydrological monitoring network (22 principal gauging stations, 45 automatic water level stations) with 30-minute telemetry to a central database, and maintains records dating back to at least the 1990s — but all data access is gated behind formal agency requests. India–Bhutan bilateral data-sharing discussions (February 2026) focused on trans-boundary flood forecasting, not public data publication. The structural barrier is institutional rather than technical: Bhutan has functioning monitoring infrastructure and an English-language governance environment, but no policy mandating open publication of hydropower or reservoir data. The NCHM Hydromet Roadmap 2024–2034, published with World Bank support, targets 'reliable data management systems' and improved service delivery but does not commit to open data portals. Without a specific open data mandate or regulatory requirement for DGPC/BPC to publish operational data, Bhutan's score on data availability, coverage, historical depth, and update frequency will remain near zero regardless of the underlying monitoring capacity. Improvement pathway: Bhutan could achieve a significant RTI score uplift — potentially into the 40–50 range — by (1) mandating BPSO to publish daily reservoir levels alongside its existing daily generation data, (2) activating a public viewer on the NCHM hydrological monitoring network already transmitting real-time data, and (3) publishing DGPC's historical inflow records for the Wangchu, Punatshangchu, and Mangdechhu basins.
Evaluated by Jaime Delgado · 2026-09-15 · Methodology v1.3.0