Spain · Guadalajara
Rio Tajo Trillo water quality
Is it clean? Caution advised
Rio Tajo Trillo's official 2025 rating is Poor — below the EU standard; swimming may be discouraged or restricted by local authorities. Check for local advisories and posted flags before swimming, and see the history below for whether this is a one-off or a pattern.
11-year classification history
Official EEA classification, one rating per bathing season, 2015–2025 — real data reported by national authorities.
- 2015: Excellent2015
- 2016: Excellent2016
- 2017: Excellent2017
- 2018: Excellent2018
- 2019: Excellent2019
- 2020: Excellent2020
- 2021: Excellent2021
- 2022: Excellent2022
- 2023: Excellent2023
- 2024: Not classified2024
- 2025: Poor2025
Poor in the most recent season, and 9 of 10 classified years rated Excellent or Good.
- Excellent
- Good
- Sufficient
- Poor
- Not classified
View as table
| Year | Classification |
|---|---|
| 2015 | Excellent |
| 2016 | Excellent |
| 2017 | Excellent |
| 2018 | Excellent |
| 2019 | Excellent |
| 2020 | Excellent |
| 2021 | Excellent |
| 2022 | Excellent |
| 2023 | Excellent |
| 2024 | Not classified |
| 2025 | Poor |
- 2015Excellent — the highest official classification under the EU bathing-water assessment.
- 2016Excellent — the highest official classification under the EU bathing-water assessment.
- 2017Excellent — the highest official classification under the EU bathing-water assessment.
- 2018Excellent — the highest official classification under the EU bathing-water assessment.
- 2019Excellent — the highest official classification under the EU bathing-water assessment.
- 2020Excellent — the highest official classification under the EU bathing-water assessment.
- 2021Excellent — the highest official classification under the EU bathing-water assessment.
- 2022Excellent — the highest official classification under the EU bathing-water assessment.
- 2023Excellent — the highest official classification under the EU bathing-water assessment.
- 2024Not classified — not enough samples in this year to assign an official rating.
- 2025Poor — below the EU standard; swimming may be discouraged or restricted by local authorities.
2026 in-season sample timeline
No individual in-season sample feed has been published for Rio Tajo Trillo yet. The official 2025 classification above, from the annual EU Bathing Water report, is the most current rating available for this beach.
How measurement works
Under the EU Bathing Water Directive, national authorities take water samples through the bathing season and test them for two indicator bacteria: intestinal enterococci and E. coli. Higher counts of either indicate a greater risk of contamination from sewage or agricultural runoff.
At the end of each season, the full set of results is reported to the European Environment Agency, which assigns one of four classifications — Excellent, Good, Sufficient or Poor — based on the statistical spread of the last four seasons' samples, not a single reading. That's why the rating published in spring 2026 covers the 2025 season, and why one bad sample doesn't necessarily change the rating on its own.
Official bathing water profile ↗ · ← Back to the Rio Tajo Trillo overview · Sea temperature at Rio Tajo Trillo →
Frequently asked questions
Is Rio Tajo Trillo safe to swim in?
Best to check first: the 2025 official rating is Poor, so look for local advisories and posted flags before going in. That applies to the water around Guadalajara.
How is bathing water quality measured?
Water samples taken through the bathing season are tested for two indicator bacteria — intestinal enterococci and E. coli — with the full season's results reported to the European Environment Agency the following spring, which grades the season Excellent, Good, Sufficient or Poor under the EU Bathing Water Directive. Some national authorities, including Croatia's IZOR, also publish individual in-season samples ahead of that annual report; that isn't yet available for Rio Tajo Trillo.
How often is the water tested?
Testing happens throughout the season (typically 4+ samples, May–September), but the resulting classification is only published once, the following spring. Rio Tajo Trillo doesn't yet have a published in-season feed, so the annual rating above is the most current figure on hand.