ULTIMATE GOAL:
Improve upstream river access for migrating adult fish, encouraging them to return and spawn in an area that was previously inaccessible to them. Naturally improved fish stocks will help the local communities and economy of the Afon Clywedog catchment.
BACKGROUND:
For more than half a century the 16ft-high weir on the River Clywedog at Bontuchel, near Ruthin, has been an impassable obstacle for fish. A much needed fish pass is required, allowing them to breach the weir to swim further upstream.
CHALLENGE:
Working closely with the Environment Agency in an environmentally sensitive area of natural beauty.
Complete the work within the mildest half of the year before the water levels raises.
Work in a difficult area with access problems and obvious health & safety restrictions whilst minimising any obstruction to local people.
DESCRIPTION OF OPERATION:
Divert the water flow away from the excavation.
Drive trench sheets into the ground to retain the walls of the excavation whilst the tunnel is being formed at the rear of the existing wall. Incorporate steel fins into the walls of the tunnel to cut into the flow of the river and slow down the current and create a whirlpool effect within the tunnel.
Form steps within the riverbed with deep pools to enable the fish to rest out of the current.
STAGE 1: SITE BEFORE WORK COMMENCES.
STAGE 2: WEIRS WATERFLOW IS DIVERTED DOWNSTREAM AND PUMPED PRIOR CONSTRUCTION.
STAGE 3:CONSTRUCTION COMMENCES.
THE COMPLETED PROJECT
To learn more, please call us on (01248) 750193 for additional information about William Hughes Civil Engineering Limited projects.
Working closely with the Environment Agency in an environmentally sensitive area of natural beauty.
