Sustainable Urban Drainage Systems – UK Flooding Focus

Standard approaches to combatting localised flooding involve underground pipe networks that divert water away from an area as quickly as possible. This works well for the purpose that it was designed for however times have changed and so have both our ideas and our weather patterns.

Piping water away only deals with one issue, the total volume of water. It does not however address today’s issues that include water quality, biodiversity and public amenity. Modern Sustainable Urban Drainage Systems (SUDS) do and are increasingly being used in building developments largely due to regulations introduced in 2015. Whilst new developments of course always installed drainage it was very rarely sustainable. By filling an area of previously permeable ground with impermeable materials such as concrete and brick the soakaway area for surface water is greatly reduced. During flash floods or freak weather large amounts of surface would collect and be diverted elsewhere. This can have all sorts of implications when it comes to water quality, pollution and contamination. SuDS have the ability to retain large amounts of this water and release it at the rate it was designed to.

Some of the other advantages of SuDS are:

• They preserve or in many cases enhance the water quality
• They not only manage the volume of water they control the flow rate thus providing added flood protection further downstream
• Captured water can be stored and often reused via a rainwater harvesting system
• They can provide a welcome habitat for wildlife in an otherwise baron urban watercourse.

It seems now that every year flooding is happening increasingly often; in places such as Cumbria or the Somerset levels many are still rebuilding from the last floods whilst all keeping an eye on the weather for more to come. It is now a fact of life Flooding is something that we have to live with and something that we have to learn how to manage. In Devon they have even gone to the extent of reintroducing beavers back into the United Kingdom for the first time since the 16^th Century. This is something that has been debated for years but was finally won once it was recognised that these originally native mammals could play a key part in flood defence.

Of course with a greater range of SuDS available now than ever before there are further applications that can be applied to this water once captured. In a lot of cases whether it is being diverted down a pipe or into a reed bed this water can be intercepted, diverted and reused elsewhere. There are a huge range of water storage tanks available to suit both domestic and commercial purposes. After all there are a large number of non-potable functions that we use water for, why are we diverting water way and then turning on a tap to get some more?