Sennen water quality
GREENdesignated bathing water · · South West Water
Sennen is a designated bathing water in Cornwall, currently rated GREEN for swimming — No recent overflow, no pollution warning, low rainfall, no high samples. Its latest Environment Agency classification is excellent (2025), and 177 storm-overflow spills were recorded nearby in 2025. Below: live risk, recent spills, official samples, rainfall, tides and nearby reports.
Current status
Risk: GREEN No recent overflow, no pollution warning, low rainfall, no high samples.
- Active overflows nearby: 0
- Recent overflows (48h): 0
- Rainfall (48h): 1.9 mm
Official EA classification
excellent (2025)
Latest official sample
2026-08-18 — E.coli 10, enterococci 10 cfu/100ml
Latest independent sample
None published
Pollution & environment data
Recent storm overflows nearby (30 days)
No spills recorded within 5 km in the last 30 days.
In the news nearby
No recent local news matched.
Storm-overflow spills near here, by year (EDM)
Recent spills near here (precise, SWW)
- spill, 36 min2026-06-08 · ~4.5 km
- spill, 36 min2026-06-08 · ~4.5 km
Full spill history near Sennen
Download CSVEvery storm-overflow discharge Glanmor has recorded within 5 km of Sennen, newest first.
4 discharge events
| Start | End | Outfall | Distance |
|---|---|---|---|
| 2026-06-08 03:42 | 2026-06-08 04:18 | ATLANTIC / PORTH NANVEN STREAM | ~4.5 km |
| 2026-05-12 05:53 | 2026-05-12 06:05 | ATLANTIC OCEAN,OFF SENNEN COVE | ~0.6 km |
| 2026-05-01 10:16 | 2026-05-01 10:17 | ATLANTIC / PORTH NANVEN STREAM | ~4.6 km |
| 2026-04-22 11:02 | 2026-04-22 11:04 | ATLANTIC / PORTH NANVEN STREAM | ~4.6 km |
8 precise spill records (duration & volume)
| When | Detail | Distance |
|---|---|---|
| 2026-06-08 03:42 | spill, 36 min | ~4.5 km |
| 2026-06-08 03:42 | spill, 36 min | ~4.5 km |
| 2026-05-12 05:53 | spill, 12 min | ~0.6 km |
| 2026-05-12 05:53 | spill, 12 min | ~0.6 km |
| 2026-05-01 10:16 | spill, 1 min | ~4.6 km |
| 2026-05-01 10:16 | spill, 1 min | ~4.6 km |
| 2026-04-22 11:02 | spill, 1 min | ~4.6 km |
| 2026-04-22 11:02 | spill, 1 min | ~4.6 km |
Water quality — 7-year trend
Water quality in 2026 was broadly level with 2025.
| Year | EA classification | Samples | E. coli (geo-mean) | Enterococci (geo-mean) | High readings |
|---|---|---|---|---|---|
| 2019 | — | 3 | 10 cfu/100ml | 19 cfu/100ml | 0 |
| 2020 | — | 3 | 10 cfu/100ml | 18 cfu/100ml | 0 |
| 2021 | — | 5 | 10 cfu/100ml | 10 cfu/100ml | 0 |
| 2022 | — | 10 | 15 cfu/100ml | 10 cfu/100ml | 1 of 10 |
| 2023 | — | 10 | 10 cfu/100ml | 10 cfu/100ml | 0 |
| 2024 | — | 10 | 10 cfu/100ml | 10 cfu/100ml | 0 |
| 2025 | excellent | 20 | 10 cfu/100ml | 10 cfu/100ml | 0 |
| 2026 | — | 11 | 10 cfu/100ml | 11 cfu/100ml | 0 |
Geometric mean of Environment Agency samples per calendar year (the standard bathing-water statistic). "High readings" are samples at or above 500 E. coli or 200 enterococci cfu/100ml.
Sennen — frequently asked questions
Is it safe to swim at Sennen today?
Sennen is currently rated GREEN: No recent overflow, no pollution warning, low rainfall, no high samples. This is guidance only — also check official alerts and use your judgement.
Has there been a sewage spill near Sennen?
177 storm-overflow spills were recorded near Sennen in 2025 (EA Event Duration Monitoring), and 4 spill events have been logged nearby so far this year.
What is Sennen's bathing water classification?
Sennen is classified excellent for 2025 by the Environment Agency.
Data & provenance
- Last updated
- 6 min ago (2026-08-26 18:30 UTC)
- Sources
- Environment Agency (samples & classification), South West Water (overflows), EA EDM (annual spills), Open-Meteo (rainfall & tide). Full list on about.
- Confidence
- High — official classification, 4 outfalls monitored within 5 km.
- Risk model
- v0.4
- Download
- Sample timeline (JSON) · All beaches (CSV)
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