Sustainable drainage systems. (S.U.D.S).

Increasingly more and more people are having their front gardens landscaped, turning them into driveways to provide off street parking. This has obvious benefits such as lower insurance premiums and a guaranteed parking space when you get home with a car load of shopping, but there is one negative environmental impact that you may not be aware of. By creating yet another hard, impermeable surface in an urban area which already has a very low percentage of free draining land, you would be adding to an existing drainage problem.

For example: If a front garden that consisted of a small path, a lawn and a flower bed was completely paved over, the rain water that used to drain slowly through the permeable surfaces of the original garden would now run off the new paving. It would then go down into the already overworked sewers, some of which are up to a hundred years old, and then either on to the effluent treatment works or out into our natural water courses.

Obviously it is not a good idea to send rain water to a place where it is treated the same as sewage, but is there any harm in sending it out to the streams and rivers? Well the answer is yes because over 90% of rain that falls in urban areas in the U.K. is classed as “run off” (70% in sub-urban areas)so, during periods of prolonged heavy rain, a city the size of London can funnel vast amount of water out very quickly which can cause flooding further down the line.

More vehicles on our roads mean more pollutants, especially hydrocarbons get mixed into the run-off water and when directed out to our natural watercourses they can cause devastating effects to the fauna and flora of our streams and rivers.

Since the 1st October 2008, planning permission has been required if you would like to pave over five square metres in your front garden using non permeable paving.

There are however several solutions:

You can pay £150 and apply for planning permission then wait up to eight weeks for decision (not recommended).

You can use a perimable paving solution i.e. permeable block paving. (Not always the most attractive option)

If you have a large enough front garden you can tilt your paving towards a flower bed or “rain garden” thus allowing the water to drain down into the earth.

The most practical solution we have found, considering the limited size of many gardens, is to dig a soak away and channel the water that runs off the paving down to it. This water is slowly released into the earth and down to the water table at a manageable rate. This is, in my opinion, the best solution as we can continue to offer a choice of materials including the ever popular natural stone paving.