A Brief Description Of Drainage Systems Within The UK

This page offers a brief description of the many kinds of drainage systems you may come across in the UK. Return to the site map for more detailed pages on each subject.

Foul Water Drainage System

A system that takes foul waste only from a property or properties, foul waste being the waste water from sinks, toilets, showers, baths, dishwashers and washing machines. These systems discharge into local authority sewers before passing through sewage treatment plants, by separating the foul waste and taking it straight through to treatment plants you are not treating large volumes of storm water unnecessarily.

Storm Water Drainage Systems

A system that takes storm water only from roofs and hard standings which would normally discharge into a brook, river or water course of some description, some properties will have soak-aways to discharge into given the correct ground and sub-soil conditions.

All of the above goes straight out of the window when your plumber puts the outlet from your washing machine straight into a storm gully, or the storm water from your new extension has been tapped into you foul system. However the Environment Agency and local authorities are clamping down on this and strict guide lines are in force for new build projects with regard to the drainage systems used.

Combined Drainage System

A system that carries both foul and storm water from a property, usually found on older properties where a local authority combined sewage system is the only discharge point.

If you property predates the sixties chances are that your storm water and foul water run to the same sewer, as the population grew and more houses were built the more storm water was being added to the drainage systems. You can not predict the volume of storm water to fall at any one time and the original sewers could not cope with the sheer volume of water passing through them.

Riparian Ownership

This applies to any kind of watercourse passing beneath the curtilage of your property, you may not gain benefit from the brook, culvert or land drainage system passing through your boundaries, you may not even know it is there but you are responsible for its maintenance and upkeep.

If your not on main line drainage then you will have a septic tank, treatment plant or cesspit of some description, ordinarily the foul waste will run to one of the above tanks while the rain water was usually kept separate to help the bacteria and enzyme in the tank do their thing. The out fall from the septic tank would either run to a soak-away of possibly straight to a river or brook, you will often find the rainwater system tapped onto the outlet of a septic tank to help dilute down any effluent that may pass through the system

The vast majority of septic tanks and treatment plants are privately owned by one specific property, there are however shared units and we have also come across tank systems that are owned and maintained by the local authority.

Grey Water Drainage Systems

These systems collect household waste water from sinks, showers and baths (not toilet waste water) and re-use it both inside and outside the property, gray water can be used for toilet flushing, garden irrigation and washing purposes.

Water Harvesting Systems

Not a new idea by any means but in these greener times it has come back into vogue, these systems collect rainfall and use it in and outside of the home. The advantages of these systems are many fold from cost savings on utility bills for the home owner through to lower flood risk.

Sustainable Drainage Systems (SUDS)

Developers are now encouraged to deal with storm water run off instead of directing it towards already overloaded combined drainage systems, culverts and brooks. Systems such as underground storage areas collect storm water during prolonged or heavy rainfall and release it into existing systems at a manageable rate, permeable paving techniques unlike traditional hard standings allow storm water to soak into the sub-soil.

Highways, Car-Park Drainage

Storm water run off from roads, highways and car-parks will be contaminated with petrol, diesel and oil and is therefore classed as a waste water product, interceptors are installed so that the contaminates are separated from the water prior to its outfall into sewer systems, brooks, rivers etc. Systems such as Swales and basins are used as part of the SUDS guidelines.

Food Preparation Drainage

Industrial Process Systems

Many industrial processes create waste water with separation tanks, settlement tanks and weir systems used to separate heavy oils, silt and contaminants prior to the water out falling to its final destination or being removed from site..

Land Drainage Systems

Drainage systems installed to drain waterlogged ground, lawns and playing and sports fields, traditionally constructed from butted clay pipes with modern systems being constructed from perforated clay and plastic pipes.

Culvert Systems

Water courses such as brooks, streams, rivers were often culverted for land reclamation and irrigation purposes, these systems are usually a riparian ownership issue.