Recent innovations with concrete block permeable paving help meet regulatory requirements while reducing costs and land-take.
By its very nature, concrete block permeable paving is uniquely placed to help meet the requirements for SuDS on new developments set out in national planning policy now being applied. But it also provides a new opportunity to meet the need for water retention on site – a key element of any SuDS scheme.
The capability for permeable paving to attenuate water flow during rainfall is well known. But this principle is transformed by considering distinct storage ‘compartments’ of permeable paving using straightforward flow control with an orifice, accessible for observation and adjustment if needed, on the outlets.
This enables water storage to be deployed around a site, with flow controls simply demonstrating compliance to local authorities as part of the SuDS design approval process. Dedicated storage on valuable land, with associated excavation and construction costs, are avoided and it can help satisfy SuDS requirements on high-density schemes.
This approach is also useful for controlling flows through the pavement construction, maximising storage on sloping sites and increasing treatment times to optimise removal of pollutants within the paving construction. And concrete block permeable paving is being used in other innovative ways too. For example retrofit overlay systems can be applied over existing road bases allowing treated, attenuated water to simply discharging sideways into adjacent rain-gardens.