Managing Floodwater with Sustainable Drainage Systems (SuDS)

In a SuDS Management Train, SuDS techniques are applied in a sequential process which captures, controls, treats and finally discharges the surface water to a receiving water course or allows the water to seep underground. 

Breaking it down into its common constituents, a Management Train will be delivering some or all the following activities:

• Rainwater harvesting- capturing rainwater for reuse within a building or the surrounding area
• Pervious surfacing- allowing stormwater run-off to filter below the surface eg green roofs and permeable paving
• Infiltration- capturing runoff before slowly releasing it
• Conveyancing- to channel the stormwater run-off into storage systems. They can also provide flow control and may be natural (swales) or proprietary (i.e. engineered solutions)
• Storage or attenuation- controlling the flow and volume of runoff being discharged from the site, by storing the water and releasing it slowly. Examples include ponds, detention basins, attenuation tanks and geocellular systems
• Treatment- to remove pollutants such as hydrocarbons and sediments contained within the runoff (e.g. fuel/oil separators)

Choosing which techniques to include within a Management Train specification depends on a range of factors including the features and constraints of the site, the size and type of development that is planned, and the nature of the surrounding area. 

Klargester manufactures a range of proprietary SuDS products (the AquaCore range) including separators, flow control and attenuation tanks. 

Proprietary products can work solus or together, with or without natural solutions, to form an effective barrier against flooding in-line with EN 858-2 floodwater management regulations, particularly where space is limited.  For added peace of mind and ease of maintenance, we have equipped our separators and pumps with built-in sensor equipment and alarms.  These continuously transmit real-time operational information directly to a laptop or smartphone, meaning management teams can pick up potential issues early before any damage is done.

A SuDS Management Train is a complex, interdependent drainage system. 

Designing SuDS should only be undertaken by qualified drainage professionals, and the process should start at an early stage in the project design. 

Planning SuDS before plans are finalised, means drainage engineers can correctly assess and adjust the scheme to key factors such as expected loading and the available space. In turn, this should help ensure that the scheme will remain viable for the lifetime of the development (>100 years).

There is little doubt that flooding is a fact of life for many of us and therefore SuDS will have an increasingly important role to play in managing surface water run-off across urban developments in future.

Architects, specifiers and developers must respond to rapidly growing demand for future-proofed flood management systems that can deliver the central tenets behind SuDS - improved water quality, water quantity, amenity value and biodiversity – if we are to resolve the issue of sustainable water management in future.

It’s encouraging to see that off-mains drainage legislation in countries around the world has tightened up in recent years.  

However, the decision to relax legislation and requirements for reporting in some markets has caused concern among drainage management professionals.

Our takeout message is simple: off-mains drainage solutions should always be professionally designed and specified.  

Moral as well as legal responsibility for disposing of wastewater safely and considerately lies with the architect/specifier, developer, installer, and the property’s owner.  

Any attempt to ease the administrative burden on property owners should never be mistaken for permission to act irresponsibly and an owner’s personal liability remains unchanged.