Probably the most visible signs of flood risk management are flood defences. We build ‘hard defences’ of concrete, metal or other construction materials and we also work with natural process to reduce flood risk.
Typical hard defences include embankments, walls, weirs, sluices and pumping stations. Of these, some may only be brought into operation when a high tide or flood is forecast. An example of this is the Thames Barrier in London.
Typical use of natural processes could involve using washlands, mudflats and saltmarshes to provide space for floodwater and prevent flooding from occurring elsewhere. At the same time, this can benefit wildlife by providing areas of habitat and are often used in combination with hard defences to provide areas for recreation and tourism.
Upland areas could be managed by restoring peat bogs or blocking artificial drainage channels. Re-planting forests in floodplains will help to slow the flow of water run-off and help it filter through the soil.
In urban areas green roofs, permeable paving, surface water storage areas can be used to reduce flood risk.
By working with natural processes alongside traditional hard defences a more sustainable approach to flood risk can be achieved.
