Bathing Water classifications
Bathing Water Classifications 2025
26/11/2025
This month, the Environment Agency (EA) released the official Bathing Water Classifications for 2025. These ratings are calculated from water samples collected over the summer and reveal the level of bacterial loading at each designated bathing site. Because this reflects the amount of faecal pollution entering the water, the classifications give an indication of the relative risk for people who swim, paddle, or play in the River.
How bathing waters are classified
Throughout the bathing season, the EA regularly tests each site for two types of faecal indicator bacteria: E. coli and intestinal enterococci. High levels of these bacteria mean there is faecal pollution in the water, which can come from multiple sources including sewage, livestock, septic tanks and run-off.
To classify a site, the EA considers all the data collected and calculates the 95th and 90th percentiles (the values that 95% and 90% of the samples fall below).
The 95% value is used to decide whether a site is Excellent or Good.
The 90% value is used to determine whether a site is Sufficient.
Because different percentiles are used, the threshold for a “Sufficient” rating can be the same as, or higher than, the threshold for “Good”. Whilst this appears incorrect at first glance, it is better understood when considering that percentiles are used to classify sites rather than an average value.
How the South West performed in 2025
Across Devon, Cornwall and the Isles of Scilly (154 bathing waters):
83.3% were classified as Excellent
13% as Good
1.3% as Sufficient
1.9% as Poor
On the River Dart, Warfleet Creek retained its Excellent rating, and Dittisham saw an upgrade from Good in 2024 to Excellent in 2025 — a welcome improvement and an encouraging sign of better water quality in the lower reaches of the River.
However, Steamer Quay remained classified as Poor, and Stoke Gabriel fell from Sufficient in 2024 to Poor in 2025.
This means that of the three bathing waters rated “Poor” across the whole South West, two are on the River Dart. When a site deteriorates, the EA designates it a priority water, triggering more focused investigations into sources of pollution.
Detailed Explainer on Steamer Quay and Stoke Gabriel Results
The EA’s 2025 review identifies several key sources of faecal pollution affecting these bathing waters:
Wastewater infrastructure: including sewage spills during the bathing season and final treated effluent from wastewater treatment works
Agricultural run-off
Septic tank issues and pipe misconnections: misconnections happen when a household’s sewage pipe is mistakenly connected to a surface water drain
Findings across the catchment
Bacterial levels rise between Totnes Weir and Steamer Quay, suggesting pollution inputs from the Hems and Malt Mill Lake. This matches Friends of the Dart’s own September Data Review. The EA recommends targeted action in the Hems, Bidwell Brook, and Malt Mill Lake catchments. Bidwell Brook is currently being extensively monitored by the University of Plymouth and the Bidwell Brook partnership, so Friends of the Dart will not be investigating pollution inputs here. We will, however, continue to monitor the River Hems, introduce monitoring on Malt Mill Lake outside of the bathing season, and conduct targeted walkover surveys in collaboration with the EA to support the identification of pollution sources. A walkover conducted by the EA and Friends of the Dart in July of Yalberton Stream (feeding into Mill Pool in Stoke Gabriel) identified several pipe misconnections, now being followed up by South West Water, highlighting the effectiveness of these targeted investigations.
Microbial Source Tracking (MST) data
MST is a specialised test that helps identify the source of faecal bacterial (e.g. humans, cattle, birds, dogs). Importantly, MST only reflects the contribution from sources in a particular sample on that specific day, so multiple samples are required to confidently attribute the source of pollution to different sources.
Bidwell Brook: MST carried out by South West Water indicated agriculture as the dominant source, with human signals also present
The Hems: samples taken below Broadhempston WWTW showed both human and cattle sources, with cattle signals stronger at the time of testing
Malt Mill Lake: showed a very strong human signal, ten times higher than the cattle signal, which considering that no rainfall or sewage spills were recorded beforehand, suggests possible septic tank failures or pipe misconnections
Yalberton Stream: human and cattle inputs, plus a small dog signal
Looking ahead to the 2026 bathing season
The EA has announced several changes to its official monitoring programme:
A new Hems site will be added upstream of Broadhempston WWTW
A site on the eastern Hems will be removed from the EA’s network
An additional Bidwell Brook site will be monitored near Tigley
New monitoring will begin at Dartington Pontoon, Dartington Beach, and Holne Weir
Friends of the Dart will continue to monitor the eastern Hems to ensure the whole catchment remains well understood, and to prevent any gaps as the EA adjusts its programme.