When it rains, it's porous
Concrete and macadam driveways may soon be a thing of the past
Homeowners will soon be stopped from concreting over their front gardens without planning permission under plans unveiled to prevent devastating repeats of last summer’s flooding.
The measures were unveiled as part of a new wide ranging water strategy to tackle the effects of climate and population change. Under Mr Benn’s plans only people installing porous paving (allowing water to soak into the ground) would be able to convert their front garden without planning permission.
An area the size of 22 hyde parks has been paved over in london alone over the past decade, forcing more storm water to run into sewers until it they can no longer cope, causing severe flooding.
There has been a trend in recent years, particularly where parking is a problem, for people to pave their gardens and park on them, which is having a catastrophic effect on the ability of land to soak away water.
The strategy also proposes removing the automatic right for new developments to be connected to public sewers.
Runoff is a problem because it means less water going into the ground, which depletes aquifers. It also carries pollutants such as oil, grease and chemicals into streams and rivers and contributes to the flash flooding that we all saw last summer.
Porous paving, such as proctorpave grass and gravel reduces these problems. As the water percolates into the ground, naturally occurring bacteria help break down pollutants such as hydrocarbons. It can also reduce or eliminate the need for other drainage systems and petrol interceptors as well as cutting development costs. In addition it can also help cut future energy bills by reducing the use of air conditioning in buildings. Therefore conserving energy and financially benefiting the occupants by reducing the heat buildup around buildings. Porous paving also provides more water for trees, which, in turn, provide cooling shade and absorb carbon dioxide, a greenhouse gas that causes global warming.
Proctorpave grass and gravel grids provide porous pavements solutions. They give either a natural grass finish with 100% grass coverage or an aesthetically pleasing decorative gravel finish.
Both products are supplied in 1m x 20m rolls as opposed to the rigid blocks that other manufacturers supply which leads to quicker installation times. They also have the added advantage of being only 25mm thick which drastically cuts the amount of gravel or sand fill required and are manufactured from 100% recycled plastic. The products are laid over a type 3 open graded sub base which gives around a 30% void ratio for water storage and the gravel version can infiltrate around 25mm of storm water a minute into the sub base.