5 Towards Developing Guidelines
43
sediment downstream. This can affect the nature of the bed sediments both upstream
and downstream of a barrage, which can itself result in changes to the morphology.
5.4.4
Flooding
A barrage will affect the flood defence regime in the watercourse on which it is located
either as its primary function as in the case of the Thames Barrier or as a consequence
of a desired change in water regime such as the Cardiff Bay Barrage (see Fig. 5.2). The
principal issues involved in flood defence are:
• Adequate capacity of the gates to pass the design flows with acceptable head loss
• Upstream storage capacity whilst gates are closed
• Adequate and documented training and hand over from the designer and contractor to the barrage operators
Fig. 5.2 One of the physical models at HR Wallingford used in assessment of flood risk on the Cardiff
Bay Barrage, Wales. (Courtesy of HR Wallingford)
43
sediment downstream. This can affect the nature of the bed sediments both upstream
and downstream of a barrage, which can itself result in changes to the morphology.
5.4.4
Flooding
A barrage will affect the flood defence regime in the watercourse on which it is located
either as its primary function as in the case of the Thames Barrier or as a consequence
of a desired change in water regime such as the Cardiff Bay Barrage (see Fig. 5.2). The
principal issues involved in flood defence are:
• Adequate capacity of the gates to pass the design flows with acceptable head loss
• Upstream storage capacity whilst gates are closed
• Adequate and documented training and hand over from the designer and contractor to the barrage operators
Fig. 5.2 One of the physical models at HR Wallingford used in assessment of flood risk on the Cardiff
Bay Barrage, Wales. (Courtesy of HR Wallingford)