The partial collapse of a medieval bridge was not caused by the removal of a weir to help migrating fish, said environment chiefs.
Powick Old Bridge, near Worcester, suffered a partial collapse at the end of January with some critics blaming the removal of a weir for the build-up of driftwood and other debris which they said in turn damaged the structure.
However, Environment Agency leaders said its removal as part of Unlocking the Severn was not a factor in the accumulation of debris at the bridge which is still closed to pedestrians and cyclists.
Unlocking the Severn is a partnership project, led by the Canal & River Trust with the Environment Agency, Severn Rivers Trust and Natural England, to re-open the UK’s longest river to all fish species.
The archways of the bridge were once again on the verge of being submerged by the swollen River Teme as debris was pushed by the flood water against the structure, some near the spot where the wing wall had suffered partial collapse.
County councillor Alan Amos, in whose division the bridge sits, said: “Finding the cause of the bridge’s collapse is essential if we are to make a lasting repair and to ensure no other part of the bridge has been damaged.
“Further technical investigation has established that the probable cause was the Environment Agency’s removal of a weir upstream which allowed water to reach the bridge much faster and previously trapped debris to flow down in greater quantities at a faster speed, causing a scouring effect on the Bridge.
“The county council has now asked to see what advice the Environment Agency’s Risk Assessment gave about the consequences for the bridge of their decision to remove the weir just so fish could swim up the river the wrong way, or whether no advice was given. The county council will then decide what action to take.”
A spokesperson for the Environment Agency said: “The weir was removed by the Unlocking the Severn project to allow the easier migration of the shad fish along the River Teme.
“Removal of the weir will not have increased the amount of debris against Powick Bridge or the rate is was flowing. That is dictated by the amount of debris washed into the river and the velocity of the watercourse at times of flood. This will vary from flood to flood and is a natural occurrence.
“Riparian owners have rights and responsibilities when it comes to keeping rivers clear, including maintaining the bed and banks of the watercourse and keeping the banks clear of anything that could cause an obstruction and increase flood risk, either on their land or downstream if it is washed away.
“The Environment Agency does carry out some annual maintenance and clearance work using its permissive powers to keep water flowing. In some cases this includes removal of debris that may pose a flood risk to people and property.”