flood prevention – The Green Tau

Counting on … day 110

16th July 2025

Might one think that a ditch is just a wasted bit of land that collects water as and when it rains? Or might it, like the verge, be a potential green corridor benefitting wild life? Here is an example from Bedfordshire where a ditch was turned “into a complex wetland habitat.” (1) Or in southwest London where the work of previous generation, who canalised a local stream with the consequence that rainwater quickly flowed through causing downstream flooding, was overturned to create a vibrant biodiverse rich habitat. (2)

Rewilding ditches, streams and ponds not only improve biodiversity but help with flood prevention. (3)

(3) https://assets.rewildingbritain.org.uk/documents/Rewilding_FloodReport_AUG2016_FINAL.pdf

Counting on … day 181

30th September 2024

Householders can reduce the peak pressure on storm drains by making use of the SUDs principles.

Eg Gravel and setts rather than solid concrete drive ways, water butts (although these will need emptying before heavy storms), rain gardens and ponds etc.

The RHS explains that “a rain garden is a shallow area of ground or dip which receives run-off from roofs and other hard surfaces. It is planted with plants that can stand waterlogging for up to 48 hours at a time. More drought-tolerant plants are used towards the edges. Storm water fills the depression and then drains. A rill or channel of some kind will connect the roof downpipe to the dip. You can include other linking elements such as a water butt, rain chain, stormwater planter, or pond.” (1)

The Wetlands and Wildfowl Trust has also useful information about creating rain gardens – https://www.wwt.org.uk/discover-wetlands/gardening-for-wetlands/how-to-make-a-rain-garden/

(1) https://www.rhs.org.uk/garden-features/rain-gardens

Counting on … day 180

27th September 2024

Sustainable urban drainage systems (SUDS) rather than using drainage pipes as the immediate means of collecting rainwater, use natural features to slow and temporarily collect rainwater. This reduces the peak demands placed on drainage systems – peaks which often overwhelm the system.

SUDS may include planting flowerbeds or other green verges alongside roads and pavements, replacing hard surfaces with softer surfaces – eg concrete with gravel – and creating rain gardens, ponds and streams or rills. Rain in this way can be used to create attractive features, new habitats, and increased biodiversity.

For more information see https://www.susdrain.org/delivering-suds/using-suds/background/sustainable-drainage.html

Counting on … day 179

26th September 2024

Increasing biodiversity can reduce the risk or extent of flooding. A range of trees and shrubs, grasses and other plants will improve the capacity of the soil to absorb water and slow the rate at which falling water reaches the ground. A diverse range of plants – and therefore of root systems – helps stabilise the soil, limiting how much is washed away and securing banks.

https://www.wildlifetrusts.org/nature-can-help-prevent-flooding

https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/british-trees/flooding/