Wolvercote Mill Stream — Bathing Water Quality 2025

Classification history

2020 excluded (COVID-19 cancelled the bathing season). Source: EA BWQ API.

Wolvercote Mill Stream — FAQ

Is Wolvercote Mill Stream safe to swim?

Wolvercote Mill Stream is rated Poor for the 2025 bathing season. This means it does not meet minimum EU Bathing Water Directive standards and may pose health risks. The EA may issue an advisory against bathing. Check environment.data.gov.uk/bwq for current advisories.

What does Poor classification mean?

Poor means the site fails the minimum rBWD standard based on its 4-season assessment window. The EA may advise against bathing. This does not necessarily mean the water is unsafe on any given day, but it is the lowest classification.

What is the Gera Bathing Water Score?

The Gera Bathing Water Score (GBWS) combines two components from Environment Agency rBWD annual compliance classifications (key-free open data, OGL v3.0): (1) latest classification score (Excellent=100, Good=75, Sufficient=50, Poor=25), weighted 0.6; and (2) pass-rate across every assessed season available for the site (up to six: 2019, 2021–2025; the proportion rated Sufficient or above), weighted 0.4. Formula: GBWS = round(0.6 × latest_score + 0.4 × pass_rate × 100). Sites with fewer than 3 assessed seasons are shown as 'insufficient data'. The 2020 bathing season was cancelled due to COVID-19 and is excluded. LA-level scores are the mean GBWS of all sites within the LA that have sufficient data. Source: EA BWQ API, seasons 2019, 2021–2025.

Who monitors Wolvercote Mill Stream?

Wolvercote Mill Stream is a designated bathing water in Oxford, monitored by the Environment Agency. It is an inland bathing water. The EA takes regular water samples during the bathing season (May–September) and publishes weekly results at environment.data.gov.uk/bwq/. The annual classification is published after the season closes.