The Welsh Liberal Democrats have called for action and criticised the Welsh and UK Governments following the publication of new figures which show devastating levels of sewage entering local rivers.

According to the data, the River Tawe, River Usk and River Wye are amongst the worst-polluted rivers in the entire UK.

The three rivers all pass through Southern Powys or Cwm Tawe Valley in the Southwest of Powys/Neath Port Talbot and Swansea.

Figures show that Dwr Cymru released sewage into rivers, lakes and the sea for more than 968,000 hours last year, an increase compared to more than 916,000 hours the year before, despite public outrage and various campaigns.

Meanwhile, Hafren Dyfrdwy - which operates in parts of Radnorshire, had 1,810 sewage spills last year, the equivalent of 17,001 hours. That compares to 1,899 spills in 2023 lasting 16,229 hours.

All three local rivers have ranked among the top 20 polluted rivers across the UK:

• The River Tawe, 14th worst in the UK, 2,173 dumps for over 16,144 hours.

• The River Usk, 18th worst in the UK, 1,761 dumps for over 14,743 hours.

• The River Wye, 19th worst in the UK 2,014 dumps for over 14,640 hours.

The Welsh Liberal Democrats, who have been campaigning to clean up Welsh rivers over several years said the figures were “catastrophic” for local wildlife and risk damaging tourism and public health.

The party has accused the Welsh Government of being "asleep at the wheel" by using Dŵr Cymru's status as a "non-profit" and "arm's length" body to avoid regulation and accountability. They also criticised the previous Conservative UK Government for not tightening financial regulation of water companies, pointing to Dŵr Cymru's large executive bonuses, poor environmental record, and high customer bills.

MS for Mid & West Wales Jane Dodds said: “The Welsh Liberal Democrats have consistently pressed both the UK and Welsh Governments to take meaningful action on this growing environmental crisis. Yet, Welsh Labour has remained asleep at the wheel - using Dŵr Cymru’s status as an arm’s-length body as an excuse to avoid proper regulation and accountability.

“As a result, we’ve seen Dŵr Cymru hike customer bills and hand out ridiculously large bonuses to its executives, all while ranking among the worst water polluters in the UK.

“We will continue to hold both water companies and governments to account. Our rivers and seas are vital to our wildlife, our culture, and our economy—particularly tourism—and they deserve far better stewardship.”

MP for Brecon, Radnor & Cwm Tawe David Chadwick added: “For years, the previous Conservatives allowed water companies to get away with polluting our beautiful local rivers while paying out massive and undeserved bonuses, all while charging Welsh customers record-breaking prices.

“We need to see Dwr Cymru properly regulated, with real, enforceable punishments put in place for when they break the rules.

“I will continue to use my voice to fight for better regulation in Parliament and to defend our waterways.”