12th August, 2022
River temperatures are rising to dangerous levels in parts of the rivers Wye and Usk.
The current forecast is looking very hot and sunny from today through Sunday 15th August for the Wye and Usk river catchments. Both the Wye and Usk are currently showing extremely low water levels due to continued low levels of rain. This means, as we found in the July heatwave, that the lives of salmon, which are holed up in the lower reaches of the rivers, are at risk due to water temperatures becoming fatally high.
The Usk Brecon Webcam shows that water levels at Nr Brecon are below 0 feet as of 10:50am on Friday 12th August.
The Wye and Usk Foundation have been undertaking daily water temperature measurements along both rivers and as a result of the high and rising temperatures encountered, have had no alternative but to suspend salmonid fishing below Crickhowell on the Usk and below Builth Wells on the Wye. As of midnight tonight (12th August 2022), The Wye and Usk Foundation have also decided to pause salmonid fishing downstream of Brecon on the Usk and on the Monnow after both river temperatures have risen above safe levels. The extent of the ongoing closure is still under review and as the next week progresses, we may have to close Barbel fishing if the water temperatures rise above 25 degrees.
We are targeting the reopening of the affected Wye and Usk fisheries from midday on Friday 19th August. For trout and pike fisheries to reopen, river temperatures must reduce to 19 degrees or less. For salmonid fisheries to reopen, these temperatures must reduce to 18 degrees or less. Our staff, with the support of some enthusiastic citizen scientists from the Friends of the Lower Wye and Friends of the Upper Wye, will continue our daily monitoring of water temperatures in order to best assess the situation.
Please exercise caution if you are planning to be in or around the Wye and Usk or its tributaries. The river beds, where still water covered, are currently coated with extensive algae layers which are slippery and the water quality is poor for leisure use. Entering the water will also add to stressful conditions already being experienced by the fish and wildlife in the rivers.
Analyser Installation along the Usk
We are currently in the process of installing three new water analysers along the River Usk which will provide a live and continuous flow of water quality data by measuring different parameters, including total phosphorus. In addition to monitoring the effects that agriculture and sewage treatment works have on the river’s phosphorus levels, these analysers will also monitor changes in water temperature caused by climate change. This pool of data will be extremely useful in monitoring these effects, especially as increased river temperatures are expected to occur more frequently in the future.
Whilst we have unfortunately experienced several major issues with our analyser on the River Ithon, we are continually working to resolve this. However, we have an analyser which is currently running on the River Frome (Lugg sub-catchment) which continuously monitors total phosphorus and reactive phosphorus.