Sustainable drainage systems (SuDS) comprise a variety of physical structures that mimic natural drainage features and collect, clean and store runoff from developments before release to the wider environment. The key to successful SuDS is water storage and treatment strategically deployed around a site, within SuDS elements such as swales, basins, ponds and permeable paving, forming discrete sub-catchments – each defined by a flow control. This is particularly important to clean the ‘first flush’ volume carrying silt and pollutants.

Multiple shallow flow controls enable the design of an efficient and cost effective ‘management train’ using SuDS techniques at or near the surface, as set out in new the National Standards for SuDS and other guidance. The Controflow range of small orifice controls, combined with pre-filters such as permeable paving or Controflow inlet baskets, is the most cost-effective way to manage runoff along the management train, as well as at site perimeters.

Controflow flow controls are designed specifically for shallow SuDS features that integrate with the landscape, provide amenity for people and habitat for wildlife. The range is easily understood and maintained by landscape managers and modestly priced to encourage efficient multiple controls along the management train.

Controflow chambers are essential for SuDS to demonstrate agreed flow rates to regulators and to optimise spatial efficiency of SuDS on sites, minimising the loss of usable space in development. They can also enable SuDS (notably permeable paving) on sloping sites, offer protection to downstream drainage assets and optimise pollution removal, evaporation and ground infiltration to reduce discharge volumes.