France · Oise
Base Nautique de Saint Leu D'Esserent water quality
Is it clean? Yes — the water meets EU standards
Base Nautique de Saint Leu D'Esserent's official 2025 EU Bathing Water rating is Good — meets the EU bathing-water standard in the latest annual assessment. 4 of the 10 classified seasons on record have rated Excellent or Good.
11-year classification history
Official EEA classification, one rating per bathing season, 2015–2025 — real data reported by national authorities.
- 2015: Good2015
- 2016: Good2016
- 2017: Good2017
- 2018: Sufficient2018
- 2019: Sufficient2019
- 2020: Poor2020
- 2021: Poor2021
- 2022: Poor2022
- 2023: Poor2023
- 2024: Not classified2024
- 2025: Good2025
Good in the most recent season, and 4 of 10 classified years rated Excellent or Good.
- Excellent
- Good
- Sufficient
- Poor
- Not classified
View as table
| Year | Classification |
|---|---|
| 2015 | Good |
| 2016 | Good |
| 2017 | Good |
| 2018 | Sufficient |
| 2019 | Sufficient |
| 2020 | Poor |
| 2021 | Poor |
| 2022 | Poor |
| 2023 | Poor |
| 2024 | Not classified |
| 2025 | Good |
- 2015Good — meets the EU bathing-water standard in the latest annual assessment.
- 2016Good — meets the EU bathing-water standard in the latest annual assessment.
- 2017Good — meets the EU bathing-water standard in the latest annual assessment.
- 2018Sufficient — meets the minimum EU standard in the latest annual assessment.
- 2019Sufficient — meets the minimum EU standard in the latest annual assessment.
- 2020Poor — below the EU standard; swimming may be discouraged or restricted by local authorities.
- 2021Poor — below the EU standard; swimming may be discouraged or restricted by local authorities.
- 2022Poor — below the EU standard; swimming may be discouraged or restricted by local authorities.
- 2023Poor — below the EU standard; swimming may be discouraged or restricted by local authorities.
- 2024Not classified — not enough samples in this year to assign an official rating.
- 2025Good — meets the EU bathing-water standard in the latest annual assessment.
2026 in-season sample timeline
No individual in-season sample feed has been published for Base Nautique de Saint Leu D'Esserent 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 Base Nautique de Saint Leu D'Esserent overview · Sea temperature at Base Nautique de Saint Leu D'Esserent →
Frequently asked questions
Is Base Nautique de Saint Leu D'Esserent safe to swim in?
Yes. Its official 2025 EU Bathing Water rating is Good, and 4 of the 10 classified seasons on record have rated Excellent or Good. That applies to the water around Oise.
How is bathing water quality measured?
Under the EU Bathing Water Directive, samples taken through the season are tested for intestinal enterococci and E. coli, with the full-season results going to the European Environment Agency the following spring for one of four classifications — Excellent, Good, Sufficient or Poor. Some national authorities, including Croatia's IZOR, also publish individual in-season samples ahead of that annual report; that isn't yet available for Base Nautique de Saint Leu D'Esserent.
How often is the water tested?
A full season of sampling (typically 4+ samples, May–September) feeds the official annual classification, but it's only published once, the following spring. Base Nautique de Saint Leu D'Esserent doesn't have an in-season sample feed published yet, so the annual rating above is the most current figure available.