Cumbria & Lancashire Blooms
- Talkin Tarn - (09/03/2026)
- Talkin Tarn - (21/03/2026) - persistent bloom, present in April and May. Repeat reports on 18/04/2026, and 24/04/2025
- Coniston - Brown Howe (19/04/2026)
- Ullswater - Glenridding (02/07/2026 + 20/07/2026)
- Windermere - North Basin (09/07/2026 + 15/07/2026)
- Derwentwater - Keswick Camping & Caravan Site (10/07/2026)
- Thirlmere - West of Dam (14/07/2026)
- River Leven - Newby Bridge (14/07/2026)
- Windermere - Fell Foot (16/07/2026)
- Windermere - Blake Holme (Hill of Oaks) (16/07/2026)
- Derwentwater - Great Bay (20/07/2026)
- Derwentwater - Mary Mount (21/07/2026)
- Derwentwater - Marina (22/07/2026)
- Coniston - Brown Howe (23/07/2026)
- Coniston - SD 29110 91215 (19/04/2026 + 23/07/2026)
- Windermere - North Basin (09/07/2026 + 15/07/2026)
- Windermere - Fell Foot (15/07/2026)
- Windermere - Blake Holme (Hill of Oaks) (16/07/2026)
- Slipper Hill Reservoir - SD874418 (17/01/2026 + 01/07/2026 + 17/07/2026)
- Lancaster Canal - Bolton-le-Sands (14/07/2026)
- Barrowford Reservoir - SD8680140063 (17/07/2026)
- The Horns Dam - SD5738438777 (23/07/2026)
- Yarrow Country Park - SD5706115158 (23/07/2026)
- Mesnes Pond Wigan - SD5792606233 (30/07/2026)
What are the reported algal blooms in Cumbria and Lancashire?
BLUE GREEN ALGAL BLOOM REPORTS CUMBRIA & LANCASHIRE 2026
Please note that although some samples have come back as clear, blooms are transient and blue green algae could grow to excess under suitable conditions at these or other locations, so it is always advisable to take precautions. If you have any concerns, then please contact the Incident Hotline on 0800 807060 to report.
Date | Watercourse | Comments | Approximate Grid Ref | Report Origin: NIRS (EA Incident Hotline), Bloomin Algae etc. |
|
|
| Last Updated: | 30/07/2026 10:30 |
17-Jan-26 | Slipper Hill Reservoir | Confirmed on UKCEH Bloomin Algae App | SD8740041800 | Bloomin Algae |
09-Mar-26 | Talkin Tarn | Sample taken - confirmed Algal Bloom | NY5461759132 | NIRS |
21-Mar-26 | Talkin Tarn | Confirmed on UKCEH Bloomin Algae App | NY5459459043 | Bloomin Algae |
19-Apr-26 | Coniston Water - Brown Howe Wood | Confirmed on UKCEH Bloomin Algae App, no bloom found by sampler (27 April) | SD2911091215 | Bloomin Algae |
25-Apr-26 | Derwentwater - Myrtle Bay | Plausible on UKCEH Bloomin Algae App, no bloom found by sampler (27 April) | NY2540019200 | Bloomin Algae |
06-Jun-26 | Windermere - Hodge Howe Wood | Plausible on UKCEH Bloomin Algae App, no bloom found by sampler (8 June) | SD4015099150 | Bloomin Algae |
17-Jun-26 | Coniston Water - Peel Near Wood | Unconfirmed - reported to Environment Agency, no bloom found by sampler (17 June) | SD2958491808 | NIRS |
01-Jul-26 | Slipper Hill Reservoir | Sample taken - confirmed algal bloom | SD8750042000 | NIRS |
02-Jul-26 | Ullswater - Glenridding | Confirmed on UKCEH Bloomin' Algae App, no bloom found by sampler (2 July) | NY3902917048 | Bloomin' Algae |
02-Jul-26 | Derwentwater - near Crow Park | Reported 6 July. Sample taken 6 July, no bloom present | NY2625922858 | NIRS |
02-Jul-26 | Windermere - Fell Foot | Sample taken 6 July, no bloom present | SD 38126 87226 | NIRS |
08-Jul-26 | Windermere - Hodge Howe Wood | Confirmed on UKCEH Bloomin' Algae App | SD4017099170 | Bloomin' Algae |
09-Jul-26 | Windermere - Cockshott Point | Confirmed on UKCEH Bloomin' Algae App | SD3960096300 | Bloomin' Algae |
09-Jul-26 | Windermere - Low Wray Bay | Confirmed on UKCEH Bloomin' Algae App | NY3767001110 | Bloomin' Algae |
09-Jul-26 | Windermere - Waterhead | Confirmed on UKCEH Bloomin' Algae App. Sample taken 9 July, confirmed bloom | NY3760003100 | Bloomin' Algae |
10-Jul-26 | Windermere - Red Nab | Confirmed on UKCEH Bloomin' Algae App | SD3856599426 | Bloomin' Algae |
10-Jul-26 | Derwentwater - Keswick camping and | Confirmed on UKCEH Bloomin' Algae App (10 July), no bloom found by sampler (13 July) | NY2581523343 | Bloomin' Algae |
14-Jul-26 | Thirlmere - West of the dam | Confirmed on UKCEH Bloomin' Algae App. Sample taken 15 July, confirmed bloom | NY3060018800 | Bloomin' Algae |
14-Jul-26 | River Leven at Newby Bridge | Confirmed via photographic evidence | SD3718086420 | Bloomin' Algae |
14-Jul-26 | Lancaster Canal Bolton-le-Sands | Confirmed via photographic evidence | SD4873068660 | Bloomin' Algae |
15-Jul-26 | Windermere - Fell Foot | Confirmed on UKCEH Bloomin' Algae App. Sample taken 16 July, confirmed bloom. Follow up sample taken at Bathing Water site on 21 July and no bloom found | SD3807087100 | Bloomin' Algae |
15-Jul-26 | Windermere - Pull Wood Bay | Confirmed on UKCEH Bloomin' Algae App | NY36900180 | Bloomin' Algae |
16-Jul-26 | Windermere - Blake Holme (Hill of Oaks) | Reported to Environment Agency. Sample taken 16 July, bloom confirmed | SD3830789866 | NIRS |
17-Jul-26 | Barrowford Reservoir | Confirmed via photographic evidence | SD8680140063 | Bloomin' Algae |
20-Jul-26 | Derwentwater - Great Bay | Reported to UKCEH Bloomin Algae App | NY25601884 | Bloomin' Algae |
20-Jul-26 | Ullswater - Glenridding | Plausible on UKCEH Bloomin Algae App | NY392171 | Bloomin' Algae |
21-Jul-26 | Derwentwater - Mary Mount | Reported to Environment Agency. Sample clear | NY2641719266 | NIRS |
22-Jul-26 | Derwentwater - Marina | Confirmed by UKCEH Bloomin Algae App | NY256230 | Bloomin' Algae |
23-Jul-26 | The Horns Dam | Reported to Environment Agency. Sample taken 23 July, bloom confirmed | SD5738438777 | NIRS |
23-Jul-26 | Yarrow Country Park | Reported to Environment Agency. Sample taken 23 July, bloom confirmed | SD5706115158 | NIRS |
23-Jul-26 | Coniston - Brown Howe | Confirmed by UKCEH Bloomin Algae App, no bloom found by sampler | SD2908091300 | Bloomin Algae |
| 30-Jul-26 | Mesnes Pond - Wigan | Reported to Environment Agency. Sample taken 30 July, bloom confirmed | SD5792606233 | NIRS |
Can I see a map of the algal blooms in Cumbria?
Cumbria - Confirmed Blue Green Algal Blooms (updated 30/07/2026)
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 & Coniston - Confirmed Blue Green Algal Blooms (updated 30/07/2026)
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 algal blooms in Lancashire?
Lancashire - Confirmed Blue Green Algal Blooms (updated 30/07/2026)
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 blooms reported to the Bloomin' Algae app?
Check out blooms reported to the UKCEH Bloomin' Algae app in Cumbria & Lancashire here.
Archive of blooms
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.
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 |