Hensall Barrier Bank Modifications

Hensall Ings is a natural flood washland / meadow located on the right bank of the River Aire, North Yorkshire. The Ings has been modified by manmade embankments to form a raised offline flood storage area covered under the Reservoir Act.

UK Coal Mining (Kellingley) Ltd have obtained planning permission and are currently abstracting coal from a series of panels beneath the flood storage area and Hensall. This commenced in 2010 and will continue until December 2015. The effects of the mining subsidence on this area include increases in flood extent, water depth, duration of inundation and flood frequency.

The Environment Agency and UK Coal require that the standard of flood protection afforded to the villages of Hensall and Gowdall is maintained at its current performance, during and after extraction of coal from beneath this area. This requires flood defence works to be constructed whilst subsidence occurs.

JBA Bentley is delivering the design and construction of flood defence embankment modification works to Sea Bank, in Hensall Ings, to remediate the effects of the mining subsidence.

The scheme is to be delivered in two phases;

A flexible temporary flood defence solution, robust enough to allow movement during mining activity whilst maintaining the flood defence standard and operation. The temporary solution will raise defences using a combination of sheet piles and earthworks, including construction of a hydraulic control structure for an ordinary watercourse.

A Permanent flood defence raised by earthworks in Spring/Summer 2015 will optimise the use of colliery spoil material as a free issue material to minimise the importation of clay material.

The project included close consultation with Reservoir Engineer, Selby DC Planners, NYCC Highways, Danum IDB and Network Rail.

Hensall Barrier Bank Modifications has been shortlisted for a project excellence award by The Environment Agency!