H1 2026 Evaluation
Peru Reservoir Transparency
C-53Inadequate — Ranked #52 out of 167 countries
weight 30%
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Primary source evaluated
Dimension breakdown
Data Availability
20% of total score
SENAMHI's PHISIS platform publicly displays current storage volumes and fill percentages for the country's main reservoirs — approximately 15-20 systems covering the most critical hydropower (e.g. Mantaro cascade via COES) and irrigation reservoirs (Poechos, Tinajones, San Lorenzo, Gallito Ciego, Condoroma, Aguada Blanca, Lagunillas). Regular press releases confirm active monitoring with specific fill-percentage figures. However, the platform is a browser-based interactive map with no bulk download or API; COES also publishes a historical hydrology query interface covering Mantaro and other SEIN basins. ANA's SNIRH Observatory references historical reservoir data but the main analytical module (ANDREA) requires registration.
Technical Accessibility
15% of total score
No public REST API exists for reservoir storage data from any Peruvian institution. SENAMHI PHISIS is a JavaScript-rendered interactive map with date-range filtering; data cannot be bulk-downloaded or accessed programmatically without scraping. COES's HistoricoHidrologia interface provides queryable data (volume in Hm³, cota in msnm, discharge in m³/s) but delivers results through a web form, not a machine-readable endpoint. Monthly hydrological bulletins are published as PDF files only. The ANA open data portal (datosabiertos.gob.pe) hosts hydrometeorological station data but confirmed reservoir-storage series are absent. Registration is required for the ANA SNIRH analytical system.
Coverage
30% of total score
Conservative capacity-weighted estimate applied 2026-05-29. Numerator/denominator: n_covered ≈ 2,160 / n_total ≈ 3,000 hm³ across ~40 reservoirs >10 hm³ (ANA's ICOLD-registered large-dam subset is 54). Dominant capacity sits in the Mantaro hydroelectric cascade (Lago Junín/Chinchaycocha feeding Tablachaca, ~35% of national hydro generation) plus Pacific-slope irrigation systems Poechos, Tinajones, San Lorenzo, Gallito Ciego, Condoroma, Aguada Blanca, Lagunillas. SENAMHI PHISIS covers ~15–20 reservoirs daily and COES adds SEIN-connected basins (Mantaro, Rímac, Santa, Huallaga). Applying conservative downward adjustment (~-11 points) to recognise the long tail of small/medium irrigation reservoirs in the Andean highlands and mining-related impoundments that fall above the 10 hm³ threshold but are absent from SENAMHI PHISIS — they are managed locally by water user boards (juntas de usuarios) without national publication. coverage = round(100 × 2,160 / 3,000) = 72.
Historical Depth
13% of total score
COES maintains queryable hydrological records from approximately 2010 for SEIN-connected basins (Mantaro, Rímac, Santa, Huallaga), providing around 15 years of machine-readable historical data via their web interface. SENAMHI's PHISIS date-range selector implies multi-year archives for the tracked reservoirs, though the depth is unspecified. Monthly hydrological bulletins are confirmed from at least 2023-2024 onwards. SENAMHI's broader PISCO gridded dataset covers 1981-2016 for precipitation and streamflow but does not include reservoir storage volumes specifically. Pre-2010 reservoir storage series are not systematically accessible online.
Update Frequency
10% of total score
SENAMHI PHISIS conducts daily hydrological monitoring and the COES historical hydrology interface offers hourly, daily, weekly, and monthly resolution options, suggesting near-daily data ingestion for energy-relevant reservoirs. SENAMHI press releases and the Agencia Andina confirm regular periodic updates on reservoir fill levels. However, there is no confirmed publicly documented refresh schedule (unlike Brazil's ONS which publishes three times daily). Monthly hydrological bulletins are the most formally documented publication cadence. COES operational data for generation is updated in near-real-time but storage volumes are less clearly scheduled.
Methodological Transparency
8% of total score
SENAMHI operates its monitoring network in accordance with WMO technical standards and publishes technical methodology documents for its PISCO gridded precipitation and streamflow products. However, no dedicated methodology document for reservoir volume measurement (gauge type, sensor calibration, bathymetric surveys, uncertainty estimates) is publicly available for the PHISIS reservoir monitoring system. COES collects reservoir data from hydroelectric operators as part of SEIN dispatch requirements, but the data collection protocol for storage volumes is not published openly. ANA references hydrological infrastructure inventories without explaining measurement methods.
Language and Usability
5% of total score
All portals — SENAMHI PHISIS, COES, ANA SNIRH, datosabiertos.gob.pe — are entirely in Spanish with no English-language interface, translation option, or English metadata. SENAMHI's international presence via the UN-SPIDER portal and IRI Data Library provides limited English descriptions of the agency but links to Spanish-only data systems. Monthly bulletins and technical documentation are published exclusively in Spanish.
Evaluator notes
Peru presents a fragmented but partially functional reservoir data landscape. The primary public window is SENAMHI's PHISIS platform, which tracks storage volumes and fill percentages for the roughly 15-20 most strategically significant reservoirs — chiefly the large irrigation systems of the northwest Pacific slope (Poechos, Tinajones, San Lorenzo, Gallito Ciego) and, indirectly through COES, the Mantaro hydroelectric cascade that supplies roughly 35% of national hydro generation. Press releases from SENAMHI confirm regular monitoring with specific percentage figures, and COES's historical hydrology interface provides queryable daily-resolution data back to approximately 2010 for SEIN-connected basins. This functional layer is, however, difficult to exploit programmatically: no REST API exists, bulk download is not available, and the interactive interfaces require manual form queries. Data is fragmented across at least three institutions (SENAMHI, COES, ANA) that do not aggregate into a single unified portal. The gaps are substantial. Of Peru's 743 registered dams, only a small fraction (estimated 15-20 systems) receive any regular public reporting. The Mantaro reservoir complex — Lago Junín/Chinchaycocha feeding Tablachaca — is monitored by COES as part of dispatch obligations, but storage figures are embedded in a web interface rather than exposed as an open dataset. Large numbers of Andean highland reservoirs used for irrigation and mining have no public data whatsoever. The ANA's SNIRH, which in principle holds historical reservoir inventories, requires registration and is not openly accessible. No formal measurement methodology is published for the reservoir monitoring system, and all interfaces and documentation are exclusively in Spanish. Peru's score places it in a tier between minimal-transparency countries and the better-performing Latin American peers like Brazil (which exposes daily open CSVs). The energy-sector driver — COES's operational need for hydro dispatch data — creates a de facto partial data publication that would not otherwise exist. A structured open-data commitment with API access, standardised formats, and expanded coverage of water-supply reservoirs would dramatically improve Peru's RTI standing.
Evaluated by Jaime Delgado · 2026-05-29 · Methodology v1.3.0