Porthtowan water quality
AMBERdesignated bathing water · · South West Water
Porthtowan is a designated bathing water in Cornwall, currently rated AMBER for swimming — A storm overflow discharged within 5 km in the last 48 hours. Falling tide may draw discharge along the shore. Its latest Environment Agency classification is excellent (2025), and 260 storm-overflow spills were recorded nearby in 2025. Below: live risk, recent spills, official samples, rainfall, tides and nearby reports.
Current status
Risk: AMBER A storm overflow discharged within 5 km in the last 48 hours. Falling tide may draw discharge along the shore.
- Active overflows nearby: 0
- Recent overflows (48h): 4
- Rainfall (48h): 8.1 mm
Official EA classification
excellent (2025)
Latest official sample
2026-08-21 — E.coli 18, enterococci 10 cfu/100ml
Latest independent sample
None published
Pollution & environment data
Recent storm overflows nearby (30 days)
- 2026-08-27 03:41 · ended~3.6 km
- 2026-08-27 03:45 · ended~3.6 km
- 2026-08-27 12:10 · ended~3.6 km
- 2026-08-27 12:15 · ended~3.6 km
In the news nearby
No recent local news matched.
Storm-overflow spills near here, by year (EDM)
Recent spills near here (precise, SWW)
- spill, 16 min2026-08-27 · ~3.6 km
- spill, 15 min2026-08-27 · ~3.6 km
- spill, 24 min2026-08-27 · ~3.6 km
- spill, 4 min2026-07-23 · ~0.1 km
- spill, 1 min2026-07-23 · ~0.1 km
- spill, 1 min2026-07-23 · ~0.1 km
- spill, 1 min2026-07-23 · ~0.1 km
- spill, 2 min2026-07-19 · ~0.1 km
Full spill history near Porthtowan
Download CSVEvery storm-overflow discharge Glanmor has recorded within 5 km of Porthtowan, newest first.
14 discharge events
| Start | End | Outfall | Distance |
|---|---|---|---|
| 2026-08-27 12:15 | 2026-08-27 12:45 | ATLANTIC OCEAN (C) | ~3.6 km |
| 2026-08-27 12:10 | 2026-08-27 12:26 | ATLANTIC OCEAN (C) | ~3.6 km |
| 2026-08-27 03:45 | 2026-08-27 04:45 | ATLANTIC OCEAN (C) | ~3.6 km |
| 2026-08-27 03:41 | 2026-08-27 03:56 | ATLANTIC OCEAN (C) | ~3.6 km |
| 2026-07-23 19:19 | 2026-07-23 19:23 | LOCAL STREAM (S) | ~0.1 km |
| 2026-07-23 10:20 | 2026-07-23 10:21 | LOCAL STREAM (S) | ~0.1 km |
| 2026-07-19 19:30 | 2026-07-19 19:45 | LOCAL STREAM (S) | ~0.1 km |
| 2026-07-19 19:13 | 2026-07-19 19:15 | LOCAL STREAM (S) | ~0.1 km |
| 2026-06-06 10:08 | 2026-06-06 10:21 | ATLANTIC OCEAN (C) | ~3.6 km |
| 2026-06-06 07:12 | 2026-06-06 07:57 | TREVAUNANCE STREAM(S) | ~4.1 km |
| 2026-05-18 01:35 | 2026-05-18 01:50 | TREVAUNANCE STREAM(S) | ~4.6 km |
| 2026-03-02 14:09 | 2026-03-02 23:43 | PORTHTOWAN STREAM (S) | ~0.8 km |
| 2026-03-01 11:03 | 2026-03-01 14:03 | LOCAL STREAM (S) | ~0.1 km |
| 2024-10-06 15:39 | 2024-10-06 15:40 | ATLANTIC OCEAN(C) | ~4.4 km |
20 precise spill records (duration & volume)
| When | Detail | Distance |
|---|---|---|
| 2026-08-27 12:10 | spill, 16 min | ~3.6 km |
| 2026-08-27 03:41 | spill, 15 min | ~3.6 km |
| 2026-08-27 02:51 | spill, 24 min | ~3.6 km |
| 2026-07-23 19:19 | spill, 4 min | ~0.1 km |
| 2026-07-23 17:06 | spill, 1 min | ~0.1 km |
| 2026-07-23 10:20 | spill, 1 min | ~0.1 km |
| 2026-07-23 07:50 | spill, 1 min | ~0.1 km |
| 2026-07-19 19:13 | spill, 2 min | ~0.1 km |
| 2026-06-06 10:08 | spill, 13 min | ~3.6 km |
| 2026-06-06 10:08 | spill, 13 min | ~3.6 km |
| 2026-06-06 07:12 | spill, 45 min | ~4.1 km |
| 2026-06-06 07:12 | spill, 45 min | ~4.1 km |
| 2026-05-18 01:35 | spill, 15 min | ~4.6 km |
| 2026-05-18 01:35 | spill, 15 min | ~4.6 km |
| 2026-03-02 14:09 | spill, 573 min | ~0.8 km |
| 2026-03-02 14:09 | spill, 573 min | ~0.8 km |
| 2026-03-01 11:03 | spill, 180 min | ~0.1 km |
| 2026-03-01 11:03 | spill, 180 min | ~0.1 km |
| 2024-10-06 15:39 | spill, 1 min | ~4.4 km |
| 2024-10-06 15:39 | spill, 1 min | ~4.4 km |
Water quality — 7-year trend
Water quality improved in 2026: average E. coli was 19% lower than 2025.
| Year | EA classification | Samples | E. coli (geo-mean) | Enterococci (geo-mean) | High readings |
|---|---|---|---|---|---|
| 2019 | — | 3 | 10 cfu/100ml | 10 cfu/100ml | 0 |
| 2020 | — | 3 | 10 cfu/100ml | 12 cfu/100ml | 0 |
| 2021 | — | 6 | 10 cfu/100ml | 11 cfu/100ml | 0 |
| 2022 | — | 10 | 11 cfu/100ml | 12 cfu/100ml | 0 |
| 2023 | — | 12 | 11 cfu/100ml | 11 cfu/100ml | 0 |
| 2024 | — | 10 | 10 cfu/100ml | 10 cfu/100ml | 0 |
| 2025 | excellent | 20 | 13 cfu/100ml | 15 cfu/100ml | 1 of 20 |
| 2026 | — | 15 | 10 cfu/100ml | 13 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.
Porthtowan — frequently asked questions
Is it safe to swim at Porthtowan today?
Porthtowan is currently rated AMBER: A storm overflow discharged within 5 km in the last 48 hours. Falling tide may draw discharge along the shore. This is guidance only — also check official alerts and use your judgement.
Has there been a sewage spill near Porthtowan?
260 storm-overflow spills were recorded near Porthtowan in 2025 (EA Event Duration Monitoring), and 13 spill events have been logged nearby so far this year.
What is Porthtowan's bathing water classification?
Porthtowan is classified excellent for 2025 by the Environment Agency.
Data & provenance
- Last updated
- 1 h ago (2026-08-27 15:45 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, 6 outfalls monitored within 5 km.
- Risk model
- v0.4
- Download
- Sample timeline (JSON) · All beaches (CSV)
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