{"id":71811,"date":"2021-04-30T07:47:42","date_gmt":"2021-04-30T07:47:42","guid":{"rendered":"https:\/\/www.bgs.ac.uk\/?p=71811"},"modified":"2024-02-27T09:18:59","modified_gmt":"2024-02-27T09:18:59","slug":"building-with-nature-and-geology-to-protect-against-flooding","status":"publish","type":"post","link":"https:\/\/www.bgs.ac.uk\/news\/building-with-nature-and-geology-to-protect-against-flooding\/","title":{"rendered":"Building with nature and geology to protect against flooding"},"content":{"rendered":"\n
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Beaver dams instead of concrete dams, re-meandering instead of dredging, floodplain parks and wetlands instead of concrete flood walls \u2014 who wouldn\u2019t want to build with nature? For many years we have been doing just the opposite, fighting against the environment, attempting to conquer nature. The ecological impacts of these \u2018hard engineering\u2019 solutions are many, from trapping sediment and disrupting fish migrations to starving wetlands of water, turning them from greenhouse gas sinks into greenhouse gas sources<\/a>.<\/p>\n\n\n\n

Flooding and climate change<\/h2>\n\n\n\n

The aim of flood risk management is to protect people and property from the devastating impact of flooding. While a concrete wall may not add to the aesthetics or ecology of a river bank, it is usually a very effective means of achieving this aim. We need effective solutions because the risk of flooding is increasing in the UK, as the climate becomes wetter<\/a>. In England and Wales, one study<\/a> found that climate change has increased the risk of floods by at least 20 per cent and possibly by as much as 90 per cent. The latest Met Office climate projections<\/a> show that winters will continue to become wetter in the UK throughout the 21st century.<\/p>\n\n\n\n

Natural flood risk management<\/h2>\n\n\n\n

The UK\u2019s river landscapes bear little resemblance to natural landscapes. We have created hard surfaces perfect for rapid runoff, built homes and roads on floodplains and straightened, dredged and built embankments on rivers, speeding up river flow, reducing infiltration and exacerbating downstream flooding. Natural flood risk management (NFM) aims to reduce flood risk by slowing the flow of water through the landscape. Native woodland, retention ponds and woody debris dams will all help to provide storage for water in the headwaters and, lower down in the catchment, floodplains will be restored. In doing so, NFM re-establishes the natural functions of river catchments, providing habitat for a diverse wildlife. It sounds perfect, doesn\u2019t it? There is just one caveat \u2014 we are not sure how well it actually works.<\/p>\n\n\n

\"Natural<\/a>
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An example of natural flood management slowing the flow of water through the landscape. Source: Leo Peskett.<\/p>\n<\/div>\n\t\t\t\t\t

\"Expand<\/a><\/div>\n\t\t\t\t<\/figcaption><\/figure>\n\n\n

There are now over 90 NFM projects in the UK, with around 15 active schemes. There have also been developments in policy to aid the implementation of NFM, such as SEPA\u2019s production of an NFM handbook<\/a> in 2016 and Defra\u2019s 2017 review<\/a> of the evidence base and production of guidance. Despite the increase in NFM implementation, monitoring and quantitative assessment of schemes remains low and evidence<\/a> of effectiveness is still limited. However, investment in scientific research on NFM is on the rise and with it we expect find out what types of NFM work best and where.<\/p>\n\n\n\n

BGS and flooding<\/h2>\n\n\n\n

Why is BGS interested in surface water flooding? What does NFM have to do with geology? BGS\u2019s work on monitoring the effectiveness of NFM has focused on two areas: the Eddleston catchment of the River Tweed and the West Thames. <\/p>\n\n\n\t\t\t\t

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\"Eddleston<\/a>
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Flooding along Eddleston Water. BGS \u00a9 UKRI<\/p>\n<\/div>\n\t\t\t\t\t

\"Expand<\/a><\/div>\n\t\t\t\t<\/figcaption><\/figure><\/div>
\"Chemical<\/a>
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Members of the BGS groundwater team chemical sampling along Eddleston Water. BGS \u00a9 UKRI<\/p>\n<\/div>\n\t\t\t\t\t

\"Expand<\/a><\/div>\n\t\t\t\t<\/figcaption><\/figure><\/div>
\"P994148\"<\/a>
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Many of the UK\u2019s river landscapes, like the River Taff in Wales, bear little resemblance to natural landscapes.\u00a0 BGS \u00a9 UKRI<\/p>\n<\/div>\n\t\t\t\t\t

\"Expand<\/a><\/div>\n\t\t\t\t<\/figcaption><\/figure><\/div>\t\t\t\t<\/div>\n\t\t\t\t\n\n\n

Eddleston<\/h3>\n\n\n\n

The Eddleston catchment<\/a> is one of the most intensively monitored NFM observatories in the UK and BGS has been involved with the project since its inception. So far, we have found that:<\/p>\n\n\n\n