The BAM Nuttall and Mott MacDonald joint venture (BMMJV) has completed a £200m project to protect Leeds and surrounding areas from the risk of extreme flooding.
The decade-long Leeds Flood Alleviation Scheme was carried out in two phases. During the first, completed in 2017, contractors built moveable weirs that could be raised and lowered to control river levels. It was the first time such technology had been used for flood defences in this way anywhere in the UK.
In the second phase, which began in 2019, BMMJV has created a new controlled flood storage area near to Calverley, the largest infrastructure element of the entire scheme.
Chosen to be built in a location away from populated areas, it has been designed to temporarily hold up to 1.8 million cu m of floodwater (equivalent to 720 Olympic-sized swimming pools) in the event of extreme rainfall and river levels.
The 200m-long structure features two moveable flood gates, which can be raised and lowered to slowly release the water downstream in a controlled way once the threat of flooding has passed.
