Drainage is a term that comes from the French drainage and refers to the action and effect of draining. This verb, in turn, means to ensure the exit of liquids or excessive humidity through pipes, tubes or ditches. According to abbreviationfinder, DMH stands for Drainage Manhole.
For engineering and urban planning, drainage is the system of interconnected pipes that allows the evacuation of rainwater or other types of liquids. Sanitary drainage is the one that carries liquid waste from homes or industries to treatment plants, where a treatment is carried out so that the liquid can be poured into a watercourse and the hydrological cycle continues to develop.
The first drainage systems date from several millennia before Christ, although they are designs on the ground, while today underground networks are built. It was only in the 19th century that the French created the first underground system; Since then, more and more European cities in the center of the continent have followed in their footsteps, taking advantage of the nearby rivers to drain the waters.
Storm drainage, for its part, is the system that facilitates the transfer of rainwater so that it can be used. Another of its purposes, perhaps the most important, is to prevent cities from being flooded.
A poor drainage system puts a city at risk; A clear example of the consequences of poor design can be seen in the history of Hurricane Katrina, which hit the US state of New Orleans in August 2005, since the flooding that followed this catastrophe took many months to resolve.
Another danger posed by a drainage system is contamination; Since there is no strict control of the materials that are constantly discarded in the pipes, it is possible to pour toxic materials that silently threaten the entire population. On the other hand, it is important to note that when the volume of waste is small, the risk is lower. In 1992, in the Mexican city of Guadalajara, a series of explosions took place that covered more than eight kilometers, claiming many lives, due to a spill of gasoline in the sewers.
It is worth mentioning that within the universe of myths and urban legends, sewers occupy a leading role; For decades, countless encounters with unknown species or species that should not be in a city have been reported, appearing through house drains or sewers. Without a doubt, the story of the large reptiles in North American pipes is the most popular worldwide; but chilling discoveries have been made in many other parts of the planet.
As usually happens in these cases, it is very difficult to distinguish between true stories and those fabricated to generate fear in citizens; furthermore, not everyone who describes an actual experience can give details or concrete information about the creature they have seen. It has been shown, however, that the unusual mixture of organic matter that takes place in the sewers has given rise to species that are not found in other ecosystems, which confirms that it is absolutely possible to sight a rare living being in the drainage systems; This does not rule out the fact that many times people get confused, as a result of suggestion, and notice life in a simple bundle of waste.
A geological drainage, on the other hand, is a surface transport network for water and sediments that usually permeabilizes the upper layers of a piece of land and then forms streams.
Finally, the notion of drainage is also used in medicine to refer to the tool that allows the extraction of excess fluids, sometimes abnormal, from a wound, cavity or abscess.
