There are many different types of surface water drainage available for both personal and commercial use. Typically, the most common types of surface water drainage systems are storm drains and French drains. French drains are primarily used in applications that involve smaller amounts of water, while storm drains are meant to redirect and distribute large amounts of water. Whichever drainage system is employed, however, depends entirely upon the type of property, its weather patterns, and the time and money willing to be invested into installation.
Surface water drainage can be very beneficial, especially for areas which receive heavy amounts of annual rainfall. Keeping certain areas of land free of excessive water can aid in the prevention of erosion, which can cause serious property damage. Not only that, but drainage systems also help to prevent and control flooding. In fact, one of the most common causes of flooding is improper water drainage.
One of the most commonly used surface water drainage systems is the French drain. Aside from effectively draining water, French drains come with an incredibly wide variety of benefits. They are very inexpensive to install and maintain, making it very possible for the average homeowner to install a French drain system himself. Along with that, their underground placement makes them incredibly discreet and, in some cases, aesthetically appealing.
French drains are best installed at the bottom of a slope. Basically, the French drain consists of a gravel or stone-filled trench, with a perforated pipe buried beneath. The gravel or stone serves as a way to capture flowing water while also re-directing the water down to a perforated pipe. This works because there is space between each piece of gravel or stone, allowing an area for water to travel. The water flows down to the bottom of the trench, where it enters through the holes of a perforated pipe.
The pipe then re-directs the water to a drainage outlet. A drainage outlet can be installed in a variety of places, such as larger bodies of water or man-made reservoirs. In many applications, the nearest paved road or unoccupied area is used as a drainage outlet.
Another surface water drainage system is a storm drain. Storm drains are common and mostly found in the streets of cities and suburbs. These can capture more water than a French drain due to their wider, grated opening. Water is often redirected into storm water drains using channels or the natural slope of a road or street. Water that enters a storm drain travels through an underground concrete pipe and into a larger body of water.