Managing water for people and wildlife
Wednesday 19th February 2014
Recently created rural sustainable drainage on the Bow Brook
As flood waters recede, Worcestershire Wildlife Trust is calling for long-term sustainable solutions to deal with flooding for both people and for wildlife.
The UK is in the midst of the wettest winter since records began 250 years ago and Worcestershire is no exception. Residents and businesses along the River Severn have seen the river reach 5.67metres, higher than the summer floods of 2007.
Peter Case, Water and Wetlands Officer for the Trust, explained "Our sympathy is with those individuals and local communities that have been affected by the recent flood events and we are very supportive of the fantastic effort made by the Environment Agency and others at this difficult time.
"It is vital to build resilience into Worcestershire’s landscape if this is the sort of weather we can expect more frequently.
"It’s important to make space for water and to avoid knee-jerk reactions to flood management when we’re looking at long-term solutions.
"The ‘whole-catchment’ approach to restoring our river systems may involve re-naturalising river corridors by replacing lost wetlands and marshes as well as re-foresting uplands so that water is retained at the top of the catchment for longer. A fully functioning catchment will naturally absorb water and release slowly over a longer period of time, reducing the risk of flooding communities further downstream."
Dredging isn't the solution
The Trust acknowledges that dredging in appropriate places is effective but rejects that this should be seen as a panacea to flooding.
A recent, independently produced, report by the Chartered Institute for Water and Environmental Management (CIWEM) documents how dredging sections of a river will move water faster downstream, compounding the flood issue elsewhere. A healthy river works to move sediment along; dredging can increase siltation by encouraging the river to deposit material elsewhere as it tries to reach equilibrium.
Peter continued "It is widely recognised that dredging a river to make it deeper won’t stop flooding – the volume of water is too great to be contained in the channel. If we simply dredge we run the risk of further isolating rivers from their floodplains and making them solely a way of conveying water from A to B.
"We also shouldn’t forget that trees and other bankside vegetation will help alleviate flooding by stabilising the riverside banks and helping to reduce erosion.
"Dredging and siltation isn’t great for people and it’s bad news for wildlife too – it all impacts negatively on fish, vegetation and waterborne creatures."
The Wildlife Trusts have a range of national examples that are restoring valuable habitats and are making space for water.
Working for sustainable drainage
The Trust is already currently involved in a number of schemes across Worcestershire that aim to slow water and prevent sediment from entering the main water channels – helping to reduce flood risk for homes and businesses whilst at the same time having a multitude of benefits for wildlife.
Peter added "It’s not just about owners of fields; the built environment has a role to play in managing water too. By incorporating Sustainable Drainage Systems or SuDS into the urban environment, surface water can be slowed down and held back after rainfall before seeping slowly into the soil.
"When designed well, SuDS can also use a series of open features such as swales and wetlands to clean water. Critically, these above-ground features make habitats for and contribute to accommodating wildlife.
"The Trust is constantly involved in discussions with developers and planners to help design and deliver the best sustainable drainage for new developments, both to prevent flooding and to deliver top quality new wildlife habitat."
The Trust is calling for those responsible for drainage and flood defence to take a sensitive approach to the problem, avoiding knee-jerk reactions like unnecessary dredging and aiming to create a resilient environment for people and wildlife where water is dealt with in a sustainable manner.
Tagged with: Living Landscapes, Flood, Planning, Water management