SuDS – Stormwater Management

Sustainable drainage systems or SuDS are now the preferred approach to managing surface water to reduce the risk of flooding and to provide the many benefits compared with conventional drainage.

Preventing the risk of flooding

With the increasing development of greenfield land and redevelopment of the urban areas, impermeable areas of roofs, roads, car parks and hardstanding are replacing previously permeable land through which rain percolated with only a small percentage reaching the surface water sewers. The dangers are that without proper stormwater management the increased volumes of surface water directed to existing sewers and watercourses, that were never intended to receive these increased flows, will cause overloading and a risk of flooding.

The SuDS approach

By mimicking natural drainage by incorporating different components designed to allow infiltration into the ground, provide storage on site and/or slow down (attenuate) flows of rainwater. In addition these components not only control the rainwater flow but can provide improvements in the water quality.

It is essential the rainwater is controlled at source and a treatment train incorporating the most suitable components is designed to correctly manage and provide the needed filtration and removal of hydrocarbons and if applicable soluble metals etc.

How SPEL can provide effective methods of control and improve water quality

Where underground storage of rainwater is preferred to ponding due to the land use restrictions SPEL Tankstor underground tanks, in a range of diameters and lengths, can be installed singly or interconnected. Vortex flow controllers are fitted to restrict the flow to an acceptable rate or, if drain levels do not permit, pumps can be incorporated to affect the same flow rates.

Where rainwater harvesting can be a benefit both for its use and help attenuate flows, the combined SPEL RainSave/attenuation system can be incorporated for the rainwater storage and attenuation saving cost and valuable site space.

To contain silt and at the same time separate out hydrocarbons SPEL fuel oil Separators should be incorporated at source and prior to any attenuation system.

Recommended Products & Systems

SPEL Tankstor stormwater attenuation tanks and systems with flow control


SPEL StormBrake stormwater attenuation tanks

The SPEL Storm-Brake attenuation tank is a two compartment unit with a weir overflow to storage. The first compartment incorporates the inlet and flow controller and, being small in capacity, quickly attains the head for optimum performance of the flow controller.


SPEL RainSave® rainwater harvesting systems

Designed in relation to the British Standard BS 8515:2009 ‘Rainwater harvesting systems – Code of practice’. They are fully automatically controlled incorporating high quality pump/s and SPEL Tankstor filament wound GRP underground or above ground storage tanks designed and manufactured to BS 4994/BS EN 976.


SPEL combined rainwater storage and attenuation tanks


SPEL Vortex Flow Control Chamber


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Tankstor® and Separator underground tank warranty

We warrant our Tankstor® and Separator underground tank shells, if installed strictly in accordance with the company’s relevant installation procedure (TSII).


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