The game was held to celebrate the restoration of part of the Telford river, which has been hidden away in an underground culvert since the 1970s.
The Mad Brook, which is sometimes called the Madebrook, has for years been contaminated by toxic run-off from roads, car parks, industrial sites and misconnected domestic sewage pipes. Efforts are under way to tackle both the source of pollution and its treatment, but bringing streams back into sunlight helps break down the pollutants, while natural, rocky river-beds oxygenate the water as it ripples and spills over stones.
Colin Preston, chief executive of Shropshire Wildlife Trust, said: "The loss of flowing water from many towns is a cause of regret for many reasons. Everyone loves to watch water tumbling over rocks and to see swans, ducks and dragonflies, as it is good for the soul.
"But shutting water away in the dark also affects its quality and this is what is driving a new policy of bringing piped streams and rivers back into the open air," he added.
The project was funded by the Environment Agency and carried out by Shropshire Wildlife Trust in partnership with Telford & Wrekin Council, Severn Trent Water, Severn Gorge Countryside Trust and local community groups.