Removal of water or fluids from an area is called drainage. Unwanted or excess water or fluids (for example, water containing different types of wastes) can sometimes accumulate on surface or sub-surface areas. Effective and efficient drainage systems are necessary where such unwanted or excess water needs to be disposed off or in general to manage water supplies. Failure of drainage system can lead to long term problems which may prove difficult to deal with at later stages.
Common drainage problems include leakage due to low quality drain systems. Clogging of drains is another common problem. Such clogging can be due to accumulation of sediments, organic matter, fat products etc. Another common clogging problem can be due to ocher (iron hydroxide related) when the sediments and water contain reduced iron and bacteria which oxidizes and clogs the drains.
Therefore, proper foresight, planning and implementation of good quality drainage systems plays is critical.
To prevent water-logging and its damaging consequences and, in general, to manage water flow, different types of drainage systems can be implemented depending on need and situation (plain, landscape, park, building, waste water etc.). Drain pipes form an indispensable part of any drainage system. The diameter of the pipes vary depending on their particular purpose. At the lower end they can be 80 mm for flexible pipes that are used for lesser water volumes. The higher end ones dealing with large volumes of water such as in agriculture and commercial usage can have of the order of about 1000 mm diameter. Drain pipes can be made from wide variety of material such as plastic (PVC), fiber cement, clay wire, concrete or ductile wire etc.
Traditionally french drains have been and are still being used most commonly as part of ground draining systems. Such drains are sub-surface laid down in a shallow trench and covered with rock and gravel and in some cases, have perforated hollow pipe for redirecting the water. One major problem with such drainage method is that they are prone to collection of sediments over a period of time. Such sedimentation can eventually lead to blockage of the drain. Such problems with french drains can be dealt by using multi-flow drainage system. This system is based on a trade marked methodology called “Narrow Trench Installation Technology”. Multi-flow drainage uses flexible, interconnected polyethylene pipes covered in geotextile fabric. They help in rapid and efficient water collection and transit, have a longer life span and involve simpler and cheaper drain installation due to lesser trench width of about 4 inch.
To avoid water accumulation (and its damaging consequences) at the foundations of buildings, effective foundation drainage systems are necessary to be installed. Later repairs can be difficult and costly. Therefore, building and drainage contractors follow code for drains and drainage system during construction. For sub-surface drainage rigid drain tiles or perforated pipes are used as part of perimeter drains. The drain pipes are laid alongside the foundation columns close towards the base. Drainage boards help in transit of water from drain pipes to the perimeter drains thus avoiding build up of sub-surface water.