FAQs
- Scarness Bay, Bassenthwaite Lake - Confirmed (29/04/2025)
- YMCA, South Basin, Windermere - Confirmed (20/04/2025) Please note: this site is a designated Bathing Water site, so a follow up sample was collected on 29/05/25 and confirmed to be clear of blue-green algae.
- High Wray/Low Wray Bays, North Basin, Windermere - Confirmed (22/05/2025)
- Pooley Bridge, Ullswater - Confirmed (18/06/2025)
- Coniston Water - Confirmed (19/06/2025)
- Strandshag Bay, Derwent Water - Confirmed (19/06/2025)
- Gale Bay, Ullswater - Confirmed (29/06/2025)
- Waterhead, Windermere - Confirmed (11/07/2025)
- Low Wray, Windermere - Confirmed (11/07/2025)
- Myrtle Bay, Derwent Water - Confirmed (16/07/2025)
- Brandelhow Bay, Derwent Water - Confirmed (30/07/2025)
- Loweswater - Confirmed (29/09/2025)
- Rawlinson Nab, Windermere - Confirmed (14/10/2025)
- Killington Lake - Confirmed (17/10/2025)
- Poaka Beck Reservoir - Confirmed (17/10/2025)
- YMCA, South Basin, Windermere - Confirmed (20/04/2025) Please note: this site is a designated Bathing Water site, so a follow up sample was collected on 29/05/25 and confirmed to be clear of blue-green algae.
- High Wray/Low Wray Bays, North Basin, Windermere - Confirmed (22/05/2025)
- Boating Centre, Coniston - Confirmed (19/06/2025) Please note: this site is a designated Bathing Water site, a follow up sample was collected on 20/06/2025 and confirmed to be clear of blue-green algae.
- Coniston Hall Slipway, Coniston - Confirmed (19/06/2025)
- Lands Point, Coniston - Confirmed (19/06/2025)
- SD 30107 93635, Coniston - Confirmed (19/06/2025)
- Priestly Centre, Coniston - Confirmed (19/06/2025)
- Hoathwaite Landing, Coniston - Confirmed (19/06/2025)
- Waterhead, Windermere - Confirmed (11/07/2025)
- Low Wray, Windermere - Confirmed (11/07/2025)
- Rawlinson Nab, Windermere - Confirmed (14/10/2025)
- Slipper Hill Reservoir - Confirmed (09/05/2025 and 20/10/2025)
- Fishmoor Reservoir - Confirmed (23/09/2025)
- Rivington Reservoir - Confirmed (26/09/2025)
What are the confirmed algal blooms in Cumbria and Lancashire?
BLUE GREEN ALGAL BLOOM REPORTS IN CUMBRIA & LANCASHIRE 2025
Please note that although some samples have come back as clear, algae could grow to excess under suitable conditions at these or other locations on the lakes, so it is always advisable to take precautions. If there are any concerns, then please contact the Environment Agency’s Incident Hotline on 0800 807060 to report.
THE SPREADSHEET AND MAPS WILL BE UDATED WEEKLY ON A FRIDAY | |||
Date | Watercourse | Comments | Approximate Grid Ref |
|
| Last Updated: | 24/10/2025 16:20 |
27-Apr-25 | Ullswater - Howtown | No sample taken - unable to find signs of a bloom | NY 44370 19880 |
29-Apr-25 | Bassenthwaite Lake - Scarness Bay | Sample Taken - Confirmed Algal Bloom | NY 21838 30160 |
06-May-25 | Windermere - Jetty Museum | No sample taken - unable to find signs of a bloom - only green weed on rocks | SD 40199 97649 |
09-May-25 | Slipper Hill Reservoir | Sample Taken - Confirmed Algal Bloom | SD 87394 41873 |
20-May-25 | Windermere - YMCA | Sample Taken - Confirmed Algal Bloom (this site is a Bathing Water site, so a follow up sample was collected on 29/05/25 and confirmed to be clear of blue-green algae) | SD 37528 89845 |
22-May-25 | Windermere - between High Wray and Low Wray Bays | Confirmed by UKCEH Bloomin Algae App | NY 37643 00819 |
02-Jun-25 | Windermere - Millerground | Sample taken - although some algae present, well below warning threshold and bloom density | SD 40178 98749 |
02-Jun-25 | Windermere - Cockshot Wood | No sample taken - unable to find signs of a bloom | SD 39557 96436 |
05-Jun-25 | Windermere - Waterhead Jetties | No sample taken - unable to find signs of a bloom | NY 37610 03156 |
05-Jun-25 | Windermere - Millerground | Sample taken - although some algae present, everything was dying back - below warning threshold | SD 40178 98749 |
12-Jun-25 | Windermere - Hodge How | Sample taken - although some algae present, well below warning threshold and bloom density | SD 40144 99195 |
18-Jun-25 | Ullswater - Pooley Bridge | Sample Taken - Confirmed Algal Bloom | NY 46811 24073 |
19-Jun-25 | Consiton - Boating Centre | Sample Taken - Confirmed Algal Bloom | SD 30832 96953 |
19-Jun-25 | Consiton - Coniston Hall Slipway | Sample Taken - Confirmed Algal Bloom | SD 30484 96385 |
19-Jun-25 | Coniston - Lands Point | Confirmed Algal Bloom | SD 30511 96319 |
19-Jun-25 | Coniston at SD 30107 93635 | Confirmed Algal Bloom | SD 30107 93635 |
19-Jun-25 | Coniston - Priestly Centre | Sample Taken - Confirmed Algal Bloom | SD 30371 95633 |
19-Jun-25 | Coniston - Hoathwaite Landing | Confirmed by UKCEH Bloomin Algae App | SD 30177 95138 |
19-Jun-25 | Derwentwater - Strandshag Bay | Confirmed by UKCEH Bloomin Algae App | NY 26561 22132 |
20-Jun-25 | Derwentwater - Calf Close Bay | Assumed Algal Bloom as in close proximity to previously confirmed bloom | NY 26981 21336 |
29-Jun-25 | Ullswater - Gale Bay | Confirmed by UKCEH Bloomin Algae App | NY 46611 23518 |
11-Jul-25 | Windermere - Waterhead | Confirmed by UKCEH Bloomin Algae App | NY 37611 03268 |
11-Jul-25 | Windermere - Low Wray | Confirmed by UKCEH Bloomin Algae App | NY 36943 01830 |
16-Jul-25 | Derwentwater - Myrtle Bay | Confirmed by UKCEH Bloomin Algae App | NY 25607 19251 |
22-Jul-25 | Thirlmere - Dam | Sample taken - algae present but below warning threshold | NY 30906 18945 |
23-Jul-25 | Lancaster Canal at Ingol | Sample taken - clear | SD 51545 31495 |
30-Jul-25 | Derwentwater - Brandelhow Bay | Assumed Algal Bloom as in close proximity to previously confirmed bloom | NY 25500 20500 |
03-Sep-25 | Glassonby Beck ptc River Eden | Sample taken - clear | NY5645639549 |
23-Sep-25 | Fishmoor Reservoir, Blackburn | Confirmed by UKCEH Bloomin Algae App | SD69452634 |
26-Sep-25 | Rivington Reservoir | Sample Taken - Confirmed Algal Bloom | SD 62669 13772 |
29-Sep-25 | Loweswater | Confirmed by photographic evidence -sampler sent but no evidence of bloom | NY1235121459 |
14-Oct-25 | Windermere - Rawlinson Nab | Sample Taken - Confirmed Algal Bloom | SD 38411 93242 |
17-Oct-25 | Killington Lake | Sample Taken - Confirmed Algal Bloom | SD 58991 91156 |
17-Oct-25 | Poaka Beck Reservoir | Sample Taken - Confirmed Algal Bloom | SD 24290 78169 |
20-Oct-25 | Slipper Hill Reservoir | Confirmed Algal Bloom | SD 87394 41873 |
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Can I see a map of the algal blooms in Cumbria?
Cumbria - Confirmed Blue Green Algal Blooms (updated 27/10/2025)
Blue Green Algal Blooms have been confirmed at the following locations, see table above for further details:
The date shown on the map is the date on which the bloom was confirmed as blue-green algae by the Environment Agency. Unsettled conditions can disperse blooms or move them around the lake. We encourage water users to check for signs of blue-green algae before entering the water.
If you wish to report an algal bloom, please contact the Environment Agency’s Incident Hotline on 0800 807060 or report via UKCEH’s Bloomin Algae App. If you have any concerns, please contact the Environment Agency’s Incident Hotline on 0800 807060.
Can I see a map of the algal blooms in Windermere and Coniston?
Windermere - Confirmed Blue Green Algal Blooms (updated 27/10/2025)
Blue Green Algal Blooms have been confirmed at the following locations on the dates shown, see the table above for further detail:
The date shown on the map is the date on which the bloom was confirmed as blue green algae by the Environment Agency. Unsettled conditions can disperse blooms or move them around the lake. We encourage water users to check for signs of blue green algae before entering the water.
If you wish to report an algal bloom, please contact the Environment Agency’s Incident Hotline on 0800 807060 or report via UKCEH’s Bloomin Algae App. If you have any concerns, please contact the Environment Agency’s Incident Hotline on 0800 807060.
Can I see a map of algal blooms in Lancashire?
Lancashire - Confirmed Blue Green Algal Blooms (updated 27/10/2025)
Blue Green Algal Blooms have been confirmed at the following locations, see the table above for further detail:
The date show on the map is the date on which the bloom was confirmed as blue green algae by the Environment Agency. Unsettled conditions can disperse blooms or move them around the lake. We encourage water users to check for signs of blue green algae before entering the water.
If you wish to report an algal bloom, please contact the Environment Agency’s Incident Hotline on 0800 807060 or report via UKCEH’s Bloomin Algae App. If you have any concerns, please contact the Environment Agency’s Incident Hotline on 0800 807060.