FAQs
Can you provide drainage solutions for outline planning applications?
Yes, we can provide a Preliminary Drainage Assessment report which is intended to demonstrate to the Planning Authority that technical solutions are available for the disposal of foul sewerage, surface water drainage and highway drainage.
What is SUDS?
SUDS stands for Sustainable Drainage Systems. This is a hierarchy of techniques to manage surface water drainage. These include minimising impermeable surfaces and controlling site runoff. The current guidance is the Interim Code of Practice for Sustainable Drainage Systems July 2004.
How much surface water storage/ attenuation will we need?
We will calculate this by assessing the surface water runoff from your development (the impermeable areas) and using the agreed discharge rate from the site. 1 in 30 yr and 1 in 100 yr storm events are used in the assessment although some surface flooding is permitted for the 1 in 100 yr storm.
Can we develop if there is no capacity in the sewers?
Water companies will often refuse to accept surface water into their combined sewers. The preferred disposal routes in line with SUDS requirements are via 1 - soakaways and 2 - watercourses. It may be possible to install a private sewage treatment plant (package plant) if there is no foul sewer capacity.
Is SUDS a legal requirement?
The current guidance is the Interim Code of Practice for Sustainable Drainage Systems July 2004. This is used by the Planning Authority in consultation with the EA and Sewerage Operator to approve the proposed drainage solutions or set conditions to the Planning Permission relating to the drainage.
What is the preferred option for disposal of foul sewerage?
The preferred option is via the public foul sewer. If this option is not available, a private treatment works may be installed subject to satisfactory disposal of the treated effluent.
What is the preferred option for disposal of surface water?
The preferred option is via soakaway. Suitable ground conditions are required and sites with high ground water levels will not be suitable. Infiltration tests can be carried out using the relatively simple Building Regulations test and the larger BRE Digest 365 test. The second option is via a watercourse and the third is via a sewer.