Panama Reservoir Transparency

For the COVERED subset (Gatun, Alajuela/Madden, Fortuna, Bayano, Changuinola I), ACP publishes Gatun Lake current levels and 12-month daily averages at evtms-rpts.pancanal.com (no login). CSV (historical levels) and PDF (indicator report) downloads are available. ACP also publishes daily average levels for Alhajuela. IMHPA publishes current levels for Fortuna, Bayano and Changuinola I at imhpa.gob.pa/es/embalses. The AQUARIUS WebPortal aggregates 55-station watershed data but requires login. The typical covered reservoir has daily public visibility, though IMHPA's three reservoirs are HTML-only without historical CSV downloads.

For the COVERED subset, the dominant access mechanism is a mix: ACP's evtms page offers direct CSV download for Gatun historical levels and a downloadable PDF report — no registration. There is no REST API at ACP. The AQUARIUS WebPortal exposes an Export API URL but the portal requires login. IMHPA provides HTML tables for hydroelectric reservoirs; sub-pages return HTTP 403, suggesting inconsistent server configuration. Smithsonian STRI hosts ACP watershed data (15-min frequency) as zipped DOI archives. The mix lands at scrapable HTML + bulk CSV/ZIP rather than a clean API.

Conservative estimate — denominator includes private smaller hydropower reservoirs (multiple small private hydropower plants in Chiriquí and other provinces with operational storage not consolidated in IMHPA public data), small municipal supply reservoirs, and private agricultural impoundments. Methodology v1.3.0 (capacity-weighted). Covered capacity through ACP (Gatún + Alajuela publicly reported daily) plus IMHPA (Fortuna, Bayano, Changuinola I current levels) totals approximately 6,000 hm³. A realistic national denominator including private small hydropower (Estí, Lorena, etc., often only reported sporadically or not at all) and municipal supply reservoirs reaches approximately 7,000 hm³. Score = round(100 × 6,000 / 7,000) = 85. Gatún alone accounts for ~80% of national storage and is fully reported by ACP with public CSV historical access; the conservative discount reflects the systematic exclusion of private smaller hydropower live data.

MEDIAN historical depth across the 5 covered reservoirs is approximately 20+ years. ACP has daily Gatun Lake records since 1965 (60+ years) and watershed records from 1913. Alajuela likewise has multi-decade ACP coverage. STRI/ACP 15-minute interval lake level data is available as zipped DOI archives. Fortuna, Bayano and Changuinola I are harder to verify; IMHPA historical portal was returning HTTP 403. With 2 of 5 having 60+ years and 3 with shorter publicly accessible records, the median lands in the 20+ year band — though weighted toward the ACP end. Band: median 20+ years.

For the COVERED subset, the typical public cadence is DAILY. ACP's AQUARIUS-based monitoring captures water levels every 15 minutes from telemetry buoys at four Gatun Lake locations; the public-facing evtms-rpts page updates daily (24-hour and 12-month daily views). IMHPA publishes current hydroelectric reservoir levels updated within the current day. Sub-daily public publishing is limited to the login-required AQUARIUS portal. Daily is strong by regional standards.

For the COVERED subset, ACP uses the Panama Canal River Forecast System (PANFCST), adapted from the US NWS River Forecast System, and an integrated hydrometeorological system designed by the Hydrologic Research Center. These methods are described in publicly accessible partner organisation documents (HRC Water, RTI.org, Aquatic Informatics case study) and peer-reviewed literature. ACP's own pages reference the monitoring network without publishing formal methodology documents or a calibration/QA protocol. IMHPA's station network page describes three measurement classes but no comprehensive method manual is linked. ACP's public disclaimer ('estimates for information purposes only') signals methods are not standardised for external accountability.

ACP provides a full English-language interface at evtms-rpts.pancanal.com/eng/h2o/index.html — page title, labels, PDF and CSV downloads are all in English. The broader pancanal.com site has substantial English content. IMHPA's portal is Spanish-only; the /en/ URL structure exists but returns 403. ETESA's hidromet.com.pa is Spanish-only. Overall, the most internationally visible dataset (Gatun) is fully accessible in English; secondary sources for hydroelectric reservoirs are Spanish-only.