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← Reservoir Transparency Index H1 2026

H1 2026 Evaluation

Portugal Reservoir Transparency

B73

Above Average — Ranked #23 out of 167 countries

Coverage88

weight 30%

Data Availability80

weight 20%

Technical Accessibility45

weight 15%

Historical Depth85

weight 13%

Update Frequency60

weight 10%

Methodological Transparency65

weight 8%

Language and Usability40

weight 5%

Primary source evaluated

SNIRH — Sistema Nacional de Informação de Recursos Hídricos (APA)

https://snirh.apambiente.pt
✗ No API

Dimension breakdown

Data Availability

20% of total score

80

For the COVERED subset (~60 reservoirs across the 8 hydrographic regions RH1-RH8), APA publishes weekly storage bulletins consistently. The typical covered reservoir has weekly publication of storage volumes (hm³), fill percentages, and basin-level aggregates. APA publishes structured HTML tables consistently on the SNIRH portal.

Technical Accessibility

15% of total score

45

For the COVERED subset, the dominant access mechanism is structured HTML tables requiring scraping. No public REST API or bulk download endpoint. CSV exports exist for some datasets but are not consistently maintained. The SNIRH portal interface is functional but dated.

Coverage

30% of total score

88

Conservative estimate — denominator includes private hydropower operational storage (EDP and IberDrola hold operational live data not all consolidated into the APA SNIRH weekly publication), small irrigation reservoirs of Aproveitamentos Hidroagrícolas, municipal water-supply reservoirs not in the SNIRH weekly bulletin, and minor reservoirs near the 10 hm³ threshold. Methodology v1.3.0 (capacity-weighted). Covered capacity through SNIRH weekly bulletins is approximately 12,500 hm³. A realistic national denominator including the private hydropower live-data tail and small irrigation/municipal storage reaches approximately 14,200 hm³. Score = round(100 × 12,500 / 14,200) = 88. All major reservoirs across the 8 hydrographic regions are covered including transboundary basins shared with Spain; the conservative discount reflects the systematic gap in private hydropower live storage and small irrigation/municipal impoundments.

Historical Depth

13% of total score

85

MEDIAN historical depth across the ~57 covered reservoirs is approximately 15-20 years. SNIRH archives weekly data going back approximately 10-15 years online, with some seasonal basin-level summaries extending further. Long-record reservoirs (Alqueva commissioned 2002, Castelo de Bode 1951) have multi-decade institutional records. Median sits comfortably in the 10-20 years band, leaning toward the upper end. Not as deep as Spain's 35-year record.

Update Frequency

10% of total score

60

For the COVERED subset, the typical cadence is WEEKLY publication via the SNIRH bulletin. Updates are consistent but there is no daily or real-time feed.

Methodological Transparency

8% of total score

65

For the COVERED subset, APA publishes technical methodology documents for the SNIRH system and reservoir measurement protocols. Metadata per reservoir is available but scattered across different pages. Stage-storage curves and bathymetric survey histories are partially documented.

Language and Usability

5% of total score

40

Portuguese only. The SNIRH interface is functional but dated, with no English-language access path for international users.

Evaluator notes

Portugal has consistent and reliable reservoir data publication through SNIRH, with comprehensive coverage of all hydrographic regions. Under methodology v1.2.0 strict linear coverage, Portugal scores 95: SNIRH covers ~57 of ~60 reservoirs >10 hm³ in the national inventory, making it one of Europe's better-covered reservoir publication systems. Historical depth scored on the MEDIAN covered reservoir is ~15-20 years. The main weaknesses are the absence of a machine-readable API (data must be scraped from HTML), limited historical depth compared to neighbouring Spain (~35 years), and Portuguese-only access. An API endpoint plus an English-language localisation would push Portugal into the A tier.

Evaluated by Jaime Delgado · 2026-05-29 · Methodology v1.3.0

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