The Cotswold Estates and Gardens team are highly experienced in front garden makeovers, this type of project sometimes includes the creation of areas of hardstanding or paving to provide parking for cars.
Current government planning guidance allows householders to construct a new or replacement driveway of any size providing that this is constructed using a permeable surface such as gravel or permeable concrete block paving, or if the rainwater gathering on the surface is directed to a lawn or border to drain naturally.
However, if the surface to be covered is more than 5 square meters planning permission is required for laying traditional impermeable driveways that do not direct the water to a permeable area.
Why is there a need for this guidance?
Serious flooding causing damage to homes, businesses and the environment has hit the headlines many times in recent years. A contributing factor to this flooding is the inability of our drainage systems to cope with high volumes of runoff, the combined effect of paving over multiple front gardens and the resultant loss in opportunity for water to soak into the ground increases runoff and contributes to the higher risk of flooding.
What solutions can you as a homeowner adopt to mitigate this problem?
Careful garden design and choice of material can minimise the flood risk impact of your project.
Permeable paving works by replicating the drainage characteristics of an undeveloped site, where we would expect 95% of rainfall to be absorbed into the ground and 5 % to become surface water runoff. Unlike traditional non-permeable paving materials, permeable paving systems allow stormwater to percolate and infiltrate through the pavement and into the aggregate layers and/or soil below.
To allow this infiltration of water to happen the materials used in permeable construction are different from those in impermeable. Conventional construction uses Type one MOT as a sub-base hardcore, a material which contains a lot of fine sand and silt which prevents the easy travel of water. Permeable schemes use a Type 3 sub-base, this is a material made only of larger pieces of stone and effectively clean from silt and sand, this creates a water storage area which over time allows water to travel through and be released, thus reducing the likelihood of a flash flood scenario.
Alternative solutions could include keeping proposed car parking hard surfaces to a minimum by creating two paved tracks for car wheels surrounded by gravel laid over a permeable plastic weed suppression membrane which can be both a functional and visually appealing solution. Plants can be grown through the membrane with some species such as thyme even being suitable for positions underneath the car. Further car parking space can be designed into a front garden scheme using grass reinforcement grids to make a suitable but disguised surface for occasional parking needs preventing gardens from becoming quagmires.
Front garden makeovers incorporating car parking solutions need not require planning permission and considering the overall garden design and choosing the correct materials can actively contribute to water flow and flood management.