Water Quality at the Lake

UK Bathing Water Designation

The Lake is a designated UK Bathing Water site. This means we have to comply with the UK Bathing Water Standard which is a public health measure that sets water quality standards for bathing waters. There are standards for bacteria pollution and blue green algae.

The Environment Agency takes water quality samples throughout the summer swimming season (May to April) and publish these on their Bathing Water website. You can visit the Lake's water quality page on their website – see left for link.

Bacterial Pollution

The Environment Agency measure two faecal indicator organisms – Faecal Enterococci and E.coli which gives an indication of the level of bacterial pollution in the water. If both measures are within the UK bathing Water standard the last reading will be shown as “indicates acceptable water quality”. If one or both of the measures are above the UK Bathing Water Standard the last reading will be shown as “indicates unacceptable water quality”.

Please note: these are only advisory indicators. In times of heavy rain bacterial counts may spike due to run off into the Lake from the surrounding area. Bacterial counts can also fall very quickly in strong sunlight. As the bacterial measures can take a week or longer to process, the latest readings on the Bathing Water website may not reflect the situation on the day you swim.

The annual classification uses a statistical method using all the sample results from the previous four years, put simply all the results in  the preceding four years have to be within the UK Bathing Water Standard 98% of the time to meet the Bathing Water classification . It gives an indication of the general bacterial pollution in the Lake. Again it does not predict the bacterial levels on a particular day.

Blue Green Algae

The Environment Agency also sets guideline levels for Blue Green Algae. Blue-green algae can be toxic and may cause, in some people, allergic reaction to skin, eyes and nose, and vomiting or diarrhoea if swallowed. 

If we have levels of Blue Green algae above the specified levels we will put advisory notices up at the Lake so you can decide if you want to swim.

Improving Water Quality at the Lake

The Club is committed to improving water quality at the Lake and consistently meeting the UK Bathing Water standard. We have already taken many actions to improve water quality and will continue to prioritize this.  We will inform you if we know of any issues with water quality. Please look at the Water Quality noticeboard on the Ladies Changing Room side for the latest advice.

If you have any symptoms or illness you believe may be attributed to swimming at the Lake please let us know as soon as possible.


EA Water Quality Monitoring 

NB Water quality at the Lake is only monitored by the EA during the swimming season (May to September)

Improved road drains to reduce run-off from Lake road into the Lake during heavy rain. Work carried out by Bristol City Council in May 2015