Presentation on theme: "Management of future floods at Cockermouth LO: To be able to explain how a specific riverine area has been managed."— Presentation transcript:
Management of future floods at Cockermouth LO: To be able to explain how a specific riverine area has been managed
Management of future floods at Cockermouth £4.4 million pound management scheme New flood defence walls will halt the spread of the river Funding from Government and local contributors River dredged more regularly to deepen the channel New embankments raise the channel height to reduce the likelihood of extra floods New floodgates at the back of houses in Waterloo street http://www.youtube.com/watch?v=Swt16ivKnrA&list=TL WmjNqbOAVcBKWgY-TljVG9zIRu-rMqE_http://www.youtube.com/watch?v=Swt16ivKnrA&list=TL WmjNqbOAVcBKWgY-TljVG9zIRu-rMqE_
Within weeks of the floods in November 2009, the Environment Agency had published an updated Flood Management Plan for the River Derwent. Although it outlined the need for some small scale hard engineering strategies, the overall preference was for soft engineering approaches to flood defence in the area. Some of these are outlined in this presentation. Use it to make notes onto your diagram in your handout. C. Hard & soft engineering strategies to reduce the impact of flooding
i. Hard Engineering Where there already are existing properties close to the river, it is recognised that small scale hard engineering defences are required, for example at Cockermouth: Maintain the existing flood walls & flood gate – without these a further 119 properties would be at risk. In total, the Derwent has over 49km of flood walls. Cockermouth North
A section of the flood wall at Cockermouth. If the discharge were to rise, the flood wall could act to keep the water in the channel and away from the buildings.
The flood gate at the footbridge in Cockermouth. This gate can be closed during very high discharge to keep the water in the channel and prevent flooding.
i. Hard Engineering Where there already are existing properties close to the river, it is recognised that small scale hard engineering defences are required, for example at Cockermouth: Maintain the existing flood walls & flood gate – without these a further 119 properties would be at risk. In total, the Derwent has over 49km of flood walls. Cockermouth North Continue to dredge the channel in Cockermouth itself to keep it clear and free- flowing.
ii. Soft Engineering The preference will be for soft engineering strategies, however, as these are more sustainable. Use land use zoning to ensure new development does not occur in areas of high flood risk, for example to the west of the hospital. Cockermouth North
Building should be restricted in the area to the west of the hospital. This is a map produced by the Environment Agency showing areas at risk of flooding.
ii. Soft Engineering Use land use zoning to ensure new development does not occur in areas of high flood risk. Cockermouth North In the upper course, near Bassenthwaite Lake, flood defences for farmland should be removed to create safe flood zones on the floodplain around the Lake. Bassenthwaite Lake This will also help reduce the pollutants reaching Bassenthwaite, which is an SSSI.
The rapid overland flow from the Cumbrian Mountains can be allowed to be stored on the floodplain around Bassenthwaite Lake, reducing the discharge moving downstream towards Cockermouth.
Responses to the flood The government provided £1 million to help with the clean-up and repairs and agreed to pay for road and bridge repairs in Cumbria · The Cumbria Flood Recovery Fund was set up to help victims of the flood. It reached £1 million after just 10 days · Network Rail opened a temporary railway station in Workington The ‘Visit Cumbria’ website provided lists of recovery services and trades, and people who could provide emergency accommodation
Example question: For a specific riverine area explain how flooding has been managed (6)
For a specific area explain how the risks of flooding have been reduced (6) The River Derwent flows through Cockermouth and is located in Cumbria, England and suffered flooding in 2009 and 2012. Since the floods, various flood management strategies have been introduced in the area. The rivers were dredged and cleared of debris to increase the depth of the channel and reduce the chance of overflowing. Flood levees have been built around Cockermouth and the river banks raised here. Bridges have been rebuilt and strengthened at the base to withstand potential flooding. There is an improved monitoring of the river to allow better warnings next time and evacuate residents. Residents are also prepared through having sandbags and flood doors in their homes to reduce flood damage. Trees have been planted on upload slopes to increase interception which will reduce surface run-off and increase lag time so that the rivers do not fill so quickly and overflow. Also, building on floodplains has been reduced or removed so that soils are not so impermeable. Overall these strategies are quite sustainable since they balance the economic cost of management with the value of the land and properties being protected. Some residents may consider flood walls and levees to be unattractive however they will protect homes and businesses and so will be socially sustainable. And afforestation and clearing river drainage channels is environmentally sustainable since it improves how a river flows without using hard engineering which is unnatural.