1. River Conwy - flood management
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2. Reduce river flow by storing water naturally in blanket bogs.
Blocking ditches on moorlands slows the rate of flow into streams and rivers, increasing the lag time between rainfall and river peaks. As moorlands are generally found in the uplands – the areas that receive most of the rainfall, storing the water there can be very cost effective. We rely on the moorlands for a constant drip feed of water in the summer months to sustain our rivers and fill our reservoirs; for recreation (kayaking, fishing, sailing) and for animals such as otters, water voles, and fish.
Reduce river flow by storing water naturally in blanket bogs.

3. Using the floodplain as a natural store for water.
The flood scheme allows the water to flow over man-made flood banks onto the natural flood plain of the valley floor. It is then stored and drains away over a few days.
Schemes usually involve lowering flood embankments, creating spillways to provide an alternative route for flood flows thus reducing water levels in towns and villages upstream.
Farmers are compensated for letting their fields become natural storage.
Using the floodplain as a natural store for water.
Environment Agency

4. Build concrete embankments.
One way to keep water out is to set up an embankment such as that along the Thames in London or the Seine in Paris. Often recreation facilities and walkways will be added as amenities on top of the embankment. Any water pipes which flow outside the embankment need to be closed manually or be equipped with check valves so that no leakage occurs inside the barrier.
Build concrete embankments.
© Copyright N Chadwick and licensed for reuse under this Creative Commons Licence.

5. An alternative to permanent walls is a structure that is put in place in the event of a flood or raises automatically as the water level rises.
Use temporary flood defences e.g. Dutchdams or height adjustable walls.
Environment Agency

6. One way to keep water out is to set up a defence which looks more natural. The base and centre of the defence is often reinforced with concrete or stone to combat the flow of water, whilst it’s often covered with soil and turfed to provide a natural looking defence.
Build flood defences.
© Copyright Dave Dunford and licensed for reuse under this Creative Commons Licence.

7. Limit development on floodplains.
Most rivers don’t flood every year. In fact many rivers won’t flood for years. Flood plains are flat land, so their potential for development has resulted in them being built on in the past. Building on floodplains reduces their ability to be used as stores for river floods. Any buildings on the floodplain are prone to flooding, and the cost of insuring the property will increase with every flood.
The easiest way to stop building being flooded on flood plains is to stop building on them.
Limit development on floodplains.

8. Straighten and deepen channels.
Straightening the river channel aims to get the water through the system, or the town, as quickly as possible. Often the fast moving water will impact on settlements lower downstream unless they also have protection.
Deepening the channel removes river load that has been deposited over time. The load can be used to build natural embankments along the rivers. Over time, there will be a further build up sediment deposited in the river.
Straighten and deepen channels.

9. Reduce river flow by planting trees.
Planting more trees intercepts rainfall and helps take water from the soil - although large areas must be reforested to make a real difference.
Shelter belts of trees along small streams can also slow down and reduce the flow of water into rivers. Felled trees can also be laid across streams in wooded areas. They help to hold back the water and release it slowly into the river’s system. Trees take time to grow, and any change must be well managed working in partnership with landowners.
Reduce river flow by planting trees.

10. Control river flow by building dams.
Dams are expensive to build but can hold back a huge amount of water. This water can be used to supply water to homes for drinking or to farms for irrigation. Reservoirs can also be used for recreation. Once built they must be managed so that there is enough room in the reservoir for rainfall events during the winter months. Water must be released slowly during drought events to avoid reservoirs running dry. Water flowing from the dams can be used to produce electricity.
Control river flow by building dams.