A multi agency river project, which HBPW has played an instrumental part in delivering, has given a major boost to wildlife in South Yorkshire.
The Don Catchment Rivers Trust (DCRT) secured funding from the Environment Agency to install a multi-species fish and eel pass on the Hadfield Weir at Meadowhall in Sheffield
HBPW Principal Engineer, Dian Coleman, who carried out the detailed design and temporary works, said: “A weir is a barrier across a river designed to alter the flow characteristics, however, the negative effect of that process is that fish are no longer able to migrate up river to their spawning grounds.
“Fish passes, as the name implies, are installed to help fish make their way up river. The type installed at Meadowhall was a Larinier fish pass which uses a series of precisely positioned plates, or ‘baffles’, to dissipate energy from the water flowing down a formed channel, reducing the average water velocity and allowing the fish to pass more readily.”
But the project, which cost several hundred thousand pounds, was not without its challenges.
“A temporary cofferdam was constructed out of bulk sand bags to allow the area to be drained, but it was not economically possible to build a temporary dam high enough to withstand high river flows experienced after periods of prolonged rain.
“At the time of construction rainfall was very heavy and, as we anticipated, it flooded on a number of occasions, but no damage was done and work resumed after flood waters were pumped out. The project finished on schedule with no major losses.”