Rivers across Mid Wales are among those suffering from exceptionally low water levels after weeks of dry weather, with gauges on the Usk, Wye and several tributaries recording their lowest levels since records began.

Analysis by Afonydd Cymru, the umbrella organisation for Wales’ rivers, found 28 gauging stations across Wales were at their lowest recorded level as of Monday morning, with a further 46 within 3cm of the record.

The Usk is particularly badly affected. A gauging station at Crickhowell has recorded its lowest level, while the Senni and Ysgir, two important tributaries, are also at their lowest recorded levels.

The Wye is also causing concern, despite receiving additional water from the Elan Dams. More than half of Natural Resources Wales’ gauges on the river are at their lowest recorded level, including the Irfon in the upper Wye catchment.

Afonydd Cymru said the situation was particularly worrying for fish such as Atlantic salmon and sewin, whose young spend much of their lives in smaller streams.

Low water levels can lead to higher temperatures and lower oxygen levels, while making fish more vulnerable to predators and increasing the risk of streams drying out.

Some rivers have fared better because of water released from reservoirs following requests from Natural Resources Wales.

The Dee, Tywi and upper Severn are all showing stronger flows as a result of additional releases. However, tributaries without reservoir support are among those recording their lowest levels.

The organisation said the contrast showed the importance of maintaining river flows during prolonged dry periods.

It said some rain is forecast over the next fortnight, offering hope of some relief after the dry summer.

However, Afonydd Cymru warned that hotter summers and longer periods without rain are likely to put increasing pressure on Welsh rivers.

It said Wales needs healthier landscapes capable of holding more water during wet periods and releasing it gradually into rivers during dry spells.