A consensus is growing that more tree cover is needed in river catchment areas to reduce the likelihood and severity of downstream flooding as seen in the north-west of England last month. In a parliamentary debate on the floods, Defra secretary Elizabeth Truss spoke of the need to "put in place tree planting programmes that can both reduce flood risk and improve the environment at the same time".
She had previously given a figure of 22 million trees being planted in the UK between 2010 and 2020, adding that within the Government's 25-year Natural Capital Plan currently under development: "We are looking at the value of trees in the natural environment and the contribution they can make to the economy, through the timber industry, and to things like flood defences."
Floods minister Rory Stewart said: "We know that trees and vegetation can have an impact in slowing the flow of flood water and we are working closely with Environment Agency to explore the role this can play in flood risk management. This can be seen through schemes such as one that recently opened in Pickering, Yorkshire. These schemes not only reduce flood risk but can also bring bigger environmental benefits. But this only reduces the impacts of smaller floods. High levels of rain in the North West fell on already saturated ground, so this approach would not have helped in what was a truly exceptional flood."
Woodland Trust senior conservation adviser Diane Millis said: "There does seem to be a slowly dawning realisation in Government and its agencies that upstream measures to reduce flows before they reach our towns and villages are going to be needed."
She cited the Slowing the Flow project in North Yorkshire, which has seen 40,000 trees planted as well as bunds and 160 debris dams made, and the Stroud Rural SuDS in the River Frome catchment in Gloucestershire as positive developments in this direction. In addition, heather burning by grouse estates has been restricted near water courses, and run-off channels from the upland peatlands have been blocked with bales of heather.
Meanwhile, the Woodland Trust is supporting the Environment Agency's soon to be launched Working With Natural Processes research initiative, which will "develop the evidence base and the technical guidance to help authorities understand, justify, develop and implement schemes to reduce flood risk", added Millis.
An earlier study commissioned by the trust of a sheep farming area in Wales found that planting tree belts across slopes increased infiltration into the soil at more than 60 times the rate of neighbouring pastures, as well as reducing soil loss and providing shelter for the sheep.
Forest Research has also embarked on a mapping exercise to identify opportunities for woodland creation to alleviate flood risk and reduce rural diffuse pollution across England and Wales, with these being used to target Government grants under the new Countryside Stewardship scheme - though Millis pointed out that the maps remain unavailable to other potential woodland creators.
The trust's own efforts alongside local partners have seen 123ha of Cumbria's formerly heavily grazed Tebay Common in the headwaters of the Lune planted with 66,000 trees, eventually creating what Millis described as "open scrubby woods" that will increase water percolation, reduce high flows and also provide shelter for stock and wildlife. Covering 400ha, another upland project at the nearby Rydal Estate incorporating a range of measures "is the largest of its kind anywhere in England", said Millis.
Durham University honorary research fellow Dr Nick Odoni has also called for tree planting "in the low millions" across the north of England, saying: "It needs to begin soon so that the landscape is ready to offer these benefits by the time greater climate changes kick in over the next 20-30 years. We have to plan and target very carefully where we place our flood management interventions, as if we get it wrong this can cause problems downstream. But if this is done in the right way, and includes things like rewilding, it could be the most tremendous economic opportunity for the north rather than a burden."
Nationwide storm damage
Gardens across the UK have been hit by storms. Sections of Prince Charles' gardens at Birkhall, part of the Balmoral estate, were washed away, while in north-west Wales the 200-year-old walled garden at Plas Cadnant Hidden Gardens was all but destroyed by a "tidal wave" of water during Storm Eva. Owner Anthony Tavernor, who spent 20 years restoring the gardens, was "devastated" at the destruction but plans to pick up the pieces.
The one-acre gardens at the National Trust's Wordsworth House in Cockermouth were also flooded in Storm Desmond - having been extensively restored after the floods of 2009. That flood knocked over the garden's centuries-old grade I listed walls, allowing the water to escape. This time, the rebuilt walls withstood the pressure but stopped the water from leaving the garden, resulting in standing water up to 7ft in some places and a layer of sludge once the water subsided.
"We've got a lot of broken terracotta pots, all the lavenders went and we lost a lot of other plants," said head gardener Amanda Thackeray. "Those are ephemeral products so you can't get insurance cover, so we'll have to replace them - again."
The garden is filled with Georgian-era plants, including large amounts of box. Volunteers have spent some 250 hours cleaning each leaf by hand using small brushes to allow the plants to photosynthesise. The gardens and house will reopen as planned in March. Thackeray said it is possible that flooding could happen again: "But I think gardens and gardeners are resilient. We're used to all sorts of weather hitting us."
Sports fields - Expert advice for dealing with the storm damage
Taking pictures of flooded sports fields and facilities and working out what you are covered for is crucial for insurance purposes, says Horticulture Week technical editor Sally Drury. But do not rush to clear away water - heavy flooding means it could be contaminated with sewage or heavy metals from nearby factories. Instead, get samples of the water analysed to ensure that it is safe to be handled.
Having established the water is safe to work with, try to remove it before it subsides too much, otherwise the settled silt will cause problems in the pitch's root zone. Around an inch of water is ideal because the water can be pushed or pulled off the field with a drag mat, to be collected and cleaned up later.
If the water has already subsided, a combination of brushing, sweeping or vacuuming with a Trilo-type machine will be needed to remove the silt. Both scenarios will require ongoing scarification and aeration throughout the year to get oxygen back into the root zone. After the scarification and aeration it would be wise to have a soil sample analysed so that any nutrients that have washed away can be replaced.
Violent floodwaters can also damage drainage systems and make the problem worse, so check ditches and culverts are properly maintained and not blocked. If the rain continues and turf remains submerged for too long, many clubs could face completely stripping the surface and rebuilding it later in the year. Those with artificial pitches should get the water analysed, remove as much as possible while it is still standing and then call in a specialist to clean the infill.
For further details, go to http://sportengland.org/facilities-planning/tools-guidance/flood-guidance.
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