As flooding continues to worsen in the rain-sodden UK, British scientists are turning to “back-to-nature” engineering schemes to reduce the impact of these increasing frequent natural disasters.
Experts from Newcastle University are collaborating with the UK's Environmental Agency on a five-year research project to trial the viability and effectiveness of so-called "back-to-nature" flood schemes.
The environmental engineering methods referred to collectively as "Natural Flood Management" (NFM) entail the use of a landscape's own pre-existing features and endowments to impede river flow, and thus either reduce the downstream maximum water height of a flood or delay its onset. Experts believe it could be the most cost-effective means of addressing one of Britain's most besetting environmental dilemmas.
NFM brings together four key techniques for stymieing the impact of flooding, all of which involve exploiting the landscape's own natural features. Water can be stored in ponds, ditches or field attenuation bunds to attenuate flow levels, while soil infiltration zones can facilitate the entry of water into the earth at certain key locations, such as tree belts.
The flow of water can also be slowed down by increasing the presence of natural plant barriers in the floodplain or woodlands adjacent to the river.
The final NFM technique is to either restore river meanders, or divert water away from the main flow into buffer zones or provisional water storage areas, which can lengthen the course of the river and diminish its slope, thus slowing its flow.
At the demonstration site of Belford Burn in Northumberland in northeastern England, the project team has deployed these techniques to successfully reduce the volume of run-off produced by a small-scale catchment system.
In addition to diminishing the risk of flooding for low-lying areas, the team's environmental engineering of the catchment area has the added benefit of reducing pollution levels by preventing phosphorus and nitrates from being leached out of the soil.
These results were achieved at an extremely modest expense compared to competing flood prevention measures. While the Belford scheme cost around 200,000 pounds, a study of the area prior to its implementation touted the figure of 2.5 million pounds for a conventional flood prevention scheme for the town.
According research team leader Mark Wilkinson, who took part in the project while at Newcastle University and is currently with the James Hutton Institute in Aberdeem, Belford is far from unique in the UK in terms of the amenability of its natural flow paths to natural flood management, and the same methods could be applied to many other parts of the country to prevent severe flooding and safeguard people's homes.
Paul Quinn from the School of Civil Engineering and Geosciences at Newcastle university said Belford's circumstances actually typical of Britain's rural towns, with a long history of floods which a short-lived but severe. This makes NFM a far more apt solution than traditional flood prevention measures, which are too costly given the relatively modest number of properties affected.