Concrete block permeable paving is set to become the standard hard surface material for all types of development.
Traditional concrete block paving is constructed with a fall or camber in the finished surface to allow rainwater to be directed towards gullies or channels which in turn direct the water into the urban drainage network. With ever increasing construction comes greatly increased impermeable areas such as car parking areas and roadways. The runoff water from these areas needs to be dealt with effectively.Why use permeable paving?
Permeable paving offers a multi-faceted solution to this issue. Rainwater is allowed to travel through the jointing material placed in the specially designed gaps between the bricks. The rainwater then travels through a geo-textile membrane (if used), which will filter contaminants from the water before allowing it to move through the single size aggregate sub-base. It then percolates through to the soil below. This installation, known as a total infiltration system, eliminates the need for any conventional gully drains on a suitable site.
Partial infiltration or attenuation type tanked systems can be used to assist in complying with sustainable drainage systems (SUDS) or planning requirements when the sub-grade is unsuitable to accept additional drainage water. An attenuation tank may also be used to store the water from the system for re-use as non-potable water.