How rewilding reduces flood risk A natural approach to flood management that repairs and revitalises our broken ecosystems 1 2 Image: Joe Cornish, Courtesy of National Trust Images Who we are Rewilding Britain is a charity with a wild vision – to help restore natural ecological processes and enable key species to return to at least one million hectares of Britain’s land and 30% of our territorial waters over the next 100 years. Why this report Rewilding has a crucial role to play in our efforts to reduce flood risk and adapt to the impacts of climate change. Rewilding projects are long- lasting, involve communities in decision-making and improve areas for wildlife as well as people. This report looks closely at a wide range of examples and also considers findings from academic sources and NGOs. The overall conclusion is that rewilding can and does make a difference. 3 4 Introduction As our climate changes, more double by 2050 as a result of and more communities across climate change3. Britain are experiencing the impacts of flooding – and While more frequent heavy the costs to individuals and rainfall has increased flood risk, businesses are staggering. another major influence is the way in which land and water On average, flooding costs the is traditionally managed. This UK economy £1.1 billion annually report looks at how reconsidering and the disastrous floods of these methods and restoring our winter 2015 may have cost as damaged ecosystems instead much as £5 billion1. One in six can play a big role in reducing properties is at risk of flooding2. the risk of the kind of floods that And the number of households have devastated communities in at serious risk of flooding could recent years. 5 6 in the ability of our natural The environments to cope with intense periods of heavy rainfall. In line with climate change Problem predictions, we can expect such events to occur more frequently Natural water cycles have in the years to come. been disrupted by decades of managing land and water to meet The time is ripe for change and needs such as food production a number of organisations, and built developments. including conservation bodies, water companies and private Image: Brian Tozer Our cities and towns have huge landowners have taken decisive What is expanses of hard surfaces and steps. They have been running super-fast drainage systems to projects that restore natural ensure that water leaves urban processes to deliver a range of rewilding? areas as quickly and efficiently benefits, including reduced flood as possible. Our wetlands have risk. They might not be labelled Rewilding is an approach that It is about helping ecological been drained for development “rewilding” but, in essence, works with natural processes restoration to happen, while and agriculture. Rivers have that is often what they have to restore ecosystems and enabling people and wildlife been straightened so they flow been doing. reconnect society with the to thrive together. faster. Run-off has been allowed natural world. to drain upland peat bogs dry Rewilding secures the good and carry soils into our things that nature provides – waterways. clean air and water, carbon storage, flood control and more. Measures such as these have It offers a chance to reverse seriously compromised trends such as the loss of forest nature’s ability to provide cover and species. valuable environmental services that we take for granted, such as Rewilding also means restoring keeping our water clean, storing our sense of wonder and carbon and providing wild spaces enchantment with wild nature. and interconnected habitats. This has resulted in a decline in species and a reduction 7 8 Image: Mike Birkin/Friends of the Earth The numbers add up Schemes that work with The final report 4, covering all North Yorkshire project and These techniques also provide a nature to reduce flood risk three projects, finds that natural by 25% on an 18km2 scale in range of other positive impacts have been happening for flood management can and the Somerset project. These including: some time. Scientific evidence does help reduce flood risk. estimated effects apply to • Preventing erosion, trapping of their effectiveness and Beneficial measures include significant-sized flood peaks sediment, reducing loss of soil/ economic viability has, increasing upland flood storage in the order of 1 in 25 annual peat particles, carbon storage however, been lacking. areas, re-vegetating bare peat chance of occurring. Multiple and improving water quality on moors and creating leaky (or more intense single) NFM downstream. To address this, the woody dams either in waterways measures (carefully-planned and • New habitat creation, more Department for Environment or in wet woodlands alongside catchment-specific) are more attractive landscapes and Food and Rural Affairs (Defra) main channels. likely to exert a larger positive increased wildlife interest. provided funding for three cumulative effect.” • A better understanding among long-term trial schemes. The report states: communities of the many They were: “The measured local effects It goes on to say: wider benefits of good land • Slowing the Flow in Pickering, of a variety of these techniques “The total value of the flood management. Yorkshire has shown that flood peak risk reduction and other • Source to Sea in Holnicote, heights may be reduced by 4% benefits arising from these The examples here, along with Somerset or more on a 9km2 catchment projects substantially outweigh others across the country, show • Making Space for Water in the scale in the Derbyshire project, the total costs involved in what can happen when we rewild Peak District in Derbyshire. by 4% on a 69km2 scale in the implementation.” our land and water. 9 10 a sense of ownership and When can reconnection with nature. • When those involved in the scheme are open to we call it unexpected outcomes or accept that uncertainty is rewilding? part of the process. All the case studies in this report demonstrate rewilding Natural flood management techniques, from placing harnesses natural ecological and blockages in streams and rivers hydrological processes to reduce echoing how nature would work, flooding. So the synergies with to allowing scrub to regenerate rewilding approaches are clear. alongside rivers, to planting trees in places where they would grow Key elements of rewilding that naturally if not overgrazed. They we believe make something also help to inspire people to more about rewilding than basic regain their sense of wonder at conservation are when one or what wild places can offer. more of the following features is/are present: • When the overall aim of the project seeks to recreate natural processes that have When habitats and been lost (often due to human intervention). living systems are • When introducing plants, trees “Rewilding takes being restored and or wildlife occurs in efforts to inspiration from past replace lost species that would ecological damage have naturally appeared in the environments without Wis being repaired, area and will benefit wildlife necessarily attempting and people. that’s rewilding. • When the project re-engages to recreate them.” local people with their environment and gives them Dr Paul Jepson, University of Oxford 11 12 Rewilding is a big-picture solution Re-establishing the balance of nature across entire catchments is an opportunity to embrace Every patch of land in a Tree planting and natural catchment, including those in regeneration of trees and scrub, urban areas, can help reduce in particular, can significantly flood risk. reduce flooding, soil erosion and water pollution5. Uplands and floodplains, for example, can play vital roles in Studies of the Pontbren Project6 slowing the flow of water and in mid-Wales, where shelter belts providing enhanced water of trees were planted across storage. Methods include creating sheep pastures, discovered that wetlands and restoring peatland water infiltrates into the soil by blocking moorland ditches under the trees up to 60 times to stop water draining off bogs. the rate at which it infiltrates into Changes to farming practices, the soil under pasture. The tree such as low tillage and reduced roots appear to create channels stocking densities, also reduce for water flow, allowing the soil soil erosion and compaction. to act as a sponge. 13 14 Image: Steve Lucker in soil, tree types and the Sustainable Urban Drainage topography of the local area. Systems (SUDS)12 refers to various However, studies do show that, measures that deal with urban in general, woodland on upland run-off water and they are being slopes and floodplains provides used more frequently. Growing a range of benefits including vegetation on roofs and walls, restoration of wildlife habitats for example, can slow surface and reduced water pollution. This water run-off, while creating Image: Steve Lucker is why the Forestry Commission ponds or wetlands near built is mapping areas that would be environments helps to store suitable for more tree planting9. water during storms. This also, of course, encourages wildlife. Another study focused on a One research paper10 estimates whole river catchment in the New that reforesting just 5% of the Techniques like these, each Forest over an area of 100 square upland landscape reduces flood aiming to repair ecological kilometres. It found that strategic peaks by around 29%, while full damage in the built environment, planting of trees could reduce reforestation would reduce can be classed as rewilding. the height of flooding in towns them by some 50%. downstream by up to 20%7. It is important to note that A study for the National Trust11 the gathering of evidence into By contrast, heavy grazing, due concluded that at a small whether rewilding for flood risk to the removal of deep vegetation catchment scale (less than works at a catchment scale is in and compaction of soil by the 100km2) – applicable to 97% its early stages.