What makes a healthy river?

River health has captured the public imagination, particularly as overspills from sewers have been getting more attention in the media. But the condition of a river is so much more complicated than what flows into it from our water treatment systems. Agriculture, roads, how we use our drains, what we buy and even the medicines and drugs we take can all have an impact on our rivers and the plants and animals that call them home.

So how are UK rivers doing? And what needs to happen to help those waterways that are drowning in pollution?

Joining the BBC's Marnie Chesterton on stage at Green Man Festival in Wales to discuss all this is:

Dave Johnston, team leader of environmental reporting at Natural Resources Wales, whose responsibility it is to monitor Welsh rivers.

Joanne Cable, head of organisms and environment division at Cardiff University, whose focus is on biodiversity and what we at home can do to support our rivers.

Simon Evans, chief executive of The Wye and Usk Foundation, who runs citizen science projects to support these two rivers local to the festival.

Christian Dunn, wetland biologist at Bangor University, who is keen to explain the power of wetlands and has also done some surprising research into the river near Glastonbury Festival.

Presenter: Marnie Chesterton Producers: Harrison Lewis and Hannah Robins Research: Liam Collins-Jones Studio Managers: Mike Cox and Duncan Hannant Editor: Richard Collings