Adaptation needed for management of future flooding

This is the second of two blogs by volunteer and nature writer Nic Wilson, exploring the potential of natural flood management schemes to decrease the flood risk posed by climate change

With the UK climate projected to become warmer and with more winter rainfall in the years ahead, alongside increased occurrence of extreme weather including heavy summer downpours, flood management is a key part of planning for the future. Floods are expected to become more severe both inland and along the coasts, with serious implications for the natural environment and people. Coastal, surface or river flooding currently causes more than £1 billion worth of damage a year in the UK and this is only likely to increase[1]. Traditional engineering schemes will always be required to reduce risk in specific areas, but when used appropriately, natural flood management (NFM) is a nature-based solution that can play a major role in reducing flood risk whilst also beneftting habitats and communities.

Investing in nature-based solutions as part of a green recovery could help us address some of the risks posed by climate change, providing jobs and revenue for local communities. Targeted payments to land managers through the new environmental land management scheme could aid implementation of NFM schemes, protecting local communities and supporting farmers. The recent Department for Environment, Food and Rural Affairs (Defra) flood and coastal erosion risk management (FCERM) policy statement and Environment Agency FCERM strategy both highlight the importance of adopting nature-based solutions that enable us to adapt and become more resilient to climate change, and it is important that we continue to identify and deliver NFM schemes moving forward.

Peatlands

Restoration of drained and damaged peatland involves rewetting bogs, which increases their ability to store water. Re-vegetation of peatland with sphagnum moss helps the land to act as a water storage facility. Restored and healthy peatland slows the flow of water and enables storage of greater amounts of water for a longer period. All these factors help to reduce flooding risks to downstream areas.¹

Rivers and floodplains

Over the centuries, people have straightened river courses to make them easier to navigate, to improve grazing and to allow for floodplain development. These structural changes in river courses have increased the speed of flow, creating flooding issues in times of heavy rain. Re-meandering rivers, re-establishing floodplains and flood plain meadows, and creating riparian (riverbank) woodland are all ways to alleviate the risk of flooding. Floodplains capture a vast amount of water, allowing it to flow downstream at a greatly reduced rate.² Planting new woodland around rivers and on floodplains, and capturing water in floodplains and wetlands, can help slow the rate of water run-off, which in turn, reduces the problems with downstream flooding.³

 Re-introducing Beavers

The re-introduction of these native engineers helps to reduce downstream flooding and clean the water passing through rivers and streams. By building new dams in different places, beavers create an evolving mixture of habitats, with streams, pools and bare mud. Beaver dams also hold water in dry periods, help to lessen flash-flooding downstream and reduce erosion, improve water quality by holding silt, and catch pollution and agricultural run-off.⁴

^{Beavers engineer rivers that slow flashy flows and hold water in dry periods Credit: RSPB} 

Wetlands

Wetland areas can soak up excess rainwater, improve water quality, and then gradually release it into rivers, reducing the risk of flooding in built-up urban and rural areas. Conservation, restoration and creation of large areas of species rich wet grassland, wet woodland, floodplain meadows, bog, fen, and peatland is essential to ensure water can be absorbed by the landscape and released slowly, rather than all immediately being channelled into rivers and potentially overflowing and impacting communities.⁵

Urban solutions

NFM is not just an issue for the rural environment. Flooding has become more of an issue as we have built infrastructure like housing, roads and carparks, and paved over gardens, reducing the ability of the landscape to absorb water. Rainwater that once would have soaked away through soil is now channelled quickly into drains and gullies, increasing the risk of flooding. Sustainable Urban Drainage (SuDs)  aims to reduce these risks using features such as permeable surfaces which allows water to filter through into the soil, green roofs, living walls, rain gardens, parks and green spaces to soak up rainwater and allow it to drain naturally into the soil.⁶ These features also benefit wildlife and create green spaces for people living in urban environments.

Investing in nature

Investing in nature and the many people and organisations that care for it is an investment in the UK. It is investing in our health and wellbeing, relieving pressure on our healthcare systems and contributes to a healthy economy. It is predicated that flooding could cost the UK around £27 billion per year by the 2080s if we fail to act on rising greenhouse gas emissions^[2]. The recent announcement from the government to ‘double its investment in flood and coastal defences in England to £5.2 billion over the next six years’^[3] is welcomed and much needed. However, this funding must be used to increase implementation of NFM and to support community projects to help educate people about nature-based solutions at a larger scale. Nature-based solutions must be part of delivering a resilient economy, healthy communities, and a thriving natural world at the heart of ‘green recovery’ from the current covid-19 global pandemic.

Case Studies:

RSPB St Aidan’s Nature Park

At St Aidan’s in the Lower Aire Valley, UK Coal, the Environment Agency and the RSPB and have created a 400-hectare wetland nature park underpinned by its own Act of Parliament.  It stores 7.5 million m3 of flood water and can reduce the downstream flood peak by 400mm protecting homes in Allerton Bywater, Castleford and surrounding villages. More information on how St Aidan’s Nature Park helps to manage flood risk can be found here.

RSPB St Aidan’s Nature Park. February 2020 floodwater being held to reduce risk to the local community. Credit: RSPB

Airds Moss Reserve

The RSPB is active in the uplands where we are trying to demonstrate that it is possible to slow the flow of rivers and prevent flooding. We have worked with United Utilities at Haweswater in the Lake District National Park to restore degraded mire habitats, establish new woodland and restore Swindale Beck to a more natural state. This habitat creation and restoration should have beneficial effects downstream in the future.

¹ https://catchmentbasedapproach.org/wp-content/uploads/2018/11/North-West-NFM-handbook.pdf, p.28.

² https://www.wwf.org.uk/sites/default/files/2008-19/slowingflow_web.pdf

³ https://www.gov.uk/government/news/reduce-flood-risk-with-the-woodlands-for-water-scheme

⁴For more information on what the RSPB is doing to help with the re-introduction of beavers, see https://www.rspb.org.uk/our-work/our-positions-and-casework/our-positions/species/beaver-reintroduction-in-the-uk/

⁵ https://www.rspb.org.uk/globalassets/downloads/documents/positions/water-and-wetlands/natural-flood-management.pdf

⁶ http://ww2.rspb.org.uk/Images/SuDS_report_final_tcm9-338064.pdf

⁷https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/693158/25-year-environment-plan.pdf, p.52

[1] Home Truths: How climate change is impacting UK homes - https://www.theclimatecoalition.org/s/Home-Truths-Report.pdf

[2] Future Flooding Report - https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/300332/04-947-flooding-summary.pdf

[3] https://www.gov.uk/government/news/building-flood-defences-fit-for-the-future