Flood structure

Engineering activities

Activity and function

Potential hydromorphological change

Mitigation measures

Barrier, barrage or weir (including components & installations)

To hold back tidal waters in extreme events whilst allowing free flow of tidal (and fresh) water under other conditions.  To allow exclusion of tidal water for flood defence, water supply, power generation (plus secondary functions).  May be set at a level to allow overtopping in extreme events and also used for navigation in detaining water upstream.

Change in sedimentary regime (TraC)

Change to hydrodynamics (TraC)

Improve Fish Passage

Modify or Enhance Structure

Good Practice Sediment Management

Embankment or Flood wall

To prevent the inflow of tidal waters to an area of low lying land

Loss of area of intertidal zone

Change to hydrodynamics (TraC)

Manage and Restore the Intertidal Zone

Back to Guidance on selecting mitigation measures