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Usk river water issues

Once more Guy Mawle has kindly pulled together some information regarding the status of some river Usk water-related issues. He gained information very promptly from the NRW (Natural Resources Wales) about the abstraction by the Canal &Rivers Trust (CRT) at Brecon to the Monmouth & Brecon Canal.

What follows includes not only information but also some interpretation of some of the information.

Low levels and high temperature of river water

  • Some Usk fisheries have been and still are closed to fishing by clubs/owners because of the risk of fish not surviving catch and release with water temperatures above 18 degrees Centigrade.
  • Until flows improve and water temperatures stay below 18 degrees C, salmon may not survive catch and release so fishing remains closed on much of the lower reaches. The upper Usk is cooler so trout fishing has been possible.

Water abstraction

  • Since late July, Dwr Cymru Welsh Water (DCWW) has been releasing extra water, 32 Million litres per day, from Usk reservoir for abstraction at Usk town to supply Llandegfedd reservoir. This release will undoubtedly have benefitted most of the river during this long, hot summer. However, there is concern about the river is downstream of the abstraction at Usk. One dead and two distressed salmon were reported yesterday at Newbridge-on-Usk, the head of tide and there may have been more mortalities.
  • There is also concern about the abstraction at Brecon by the Canal and Rivers Trust to the Monmouth & Brecon Canal. In July, NRW advised the Trust that the level of the abstraction was too high, taking about a third of the river flow. This could have damaged the river as habitat for salmon and perhaps other protected features of the Usk SAC (Special Area of Conservation). 
  • It is not clear whether the Canal & Rivers Trust has been exploiting the extra water released from Usk reservoir to keep the canal open, but to the detriment of the river.

Reduced compensation flow from Talybont reservoir

  • As of 19 August, DCWW has reduced the compensation flow from Talybont reservoir by 7 Ml/d. The flow in the Caerfanell downstream has dropped from 17 Ml/d to 10 Ml/d. This is permitted under DCWW's licence when public water supply is at risk. The lower compensation flow is expected to continue until flows and reservoir levels improve. The impact on flows in the main river Usk is minor.


Separate to this summary, you may like to know that the group ‘Save the River Usk’ has organised a march around Crickhowell on Saturday, 17 September 2022. Those wishing to attend need to meet at Beaufort Street car park at 10 am.


Usk Fishing Association

The Chairman
The Estate Office
Glanusk Park

Tel. 01873 810414

Join the UFA and help to safeguard the future of the River Usk.