Types of Drainage System in Nigeria


Drainage is an important aspect of building construction and maintenance as well as agriculture. It is very important because if the water stays for a long time on the earth’s surface, contamination may occur. This is why a good drainage system is needed. They do not only prevent contamination but they also protect your building’s foundation. Drainage systems are designed in a way that wastewater is properly disposed of. Drainage systems also maintain the healthy conditions of the buildings. Drainage systems are of different types namely, surface drainage systems, subsurface drainage systems, slope drainage systems, and downspout and gutter systems. In this article, the various types of drainage systems in Nigeria would be addressed extensively.

Types of Drainage System in Nigeria

The types of drainage systems in Nigeria would be discussed below:

  • Downspout and Gutter Systems

The downspout and gutter system is the most used drainage system in residential homes. How this drainage system work is that the downspout is connected to the gutter. The gutter then eliminates the excess water that stores on the roof of the building. If the gutter and downspout are not constructed, the excess water would fall on the ground and the house directly which could lead to damage and possibly erosion. Also, if the gutter and downspout are not constructed, it can lead to flooding and water pooling. The downspout functions as a gutter drain. It is also a pipe that transports rainwater to the ground from the gutter.

The water collected from the roof is then channeled to the ground. The downspouts empty the water in a sloppy way to prevent pooling at the base of the downstrout. The water is drained into an aluminium extension or a rain barrel. What this aluminium does is channel water to other drainage systems around the house vicinity. They could also be channeled into underground drainage systems. All these are to ensure that the compound is not flooded.

The downspout ensures that when it rains the rainwater does not splash on the building but goes directly to the ground through the gutter. Another thing to note about the downspout is that at the base, the water is discharged far away from the foundation of the building to prevent any damage that might occur. 

  • Subsurface Drainage System

The subsurface drainage system is the type of drainage system that is normally buried under the ground. The main function of the subsurface drainage system is to eliminate any excess water that has accumulated in the soil. If you have a garden or a small farm in your compound, a subsurface drainage system helps the plants in the garden not to rot as any trapped water can cause them damage. 

How the subsurface drainage system works is that pipes are channeled underground to serve as a drain. The drain is placed under the top layer of the soil to eliminate any surplus water at the root level. The subsurface drainage system requires the digging of trenches and the building of underground pipes. In most cases, this type of drainage system is also called the French drain. The subsurface drainage system could also be made up of a series of wells.

The subsurface drainage can be constructed by breaking up soil layers through deep ploughing of the soil. The subsurface drainage enhances the overall condition of the soil because the ploughing increases soil aeration. This type of drainage system also reduces soil salinity. The subsurface drainage system prevents flooding by directing wastewater from the building. It is common knowledge that the stagnation of water can create breeding grounds for mosquitoes. 

The subsurface drainage system helps to eliminate surplus water and thereby eliminates the risk of water contamination. The subsurface drainage system also decreases the risk of erosion. This erosion can be a result of water accumulation that causes the soil to be muddy thereby leading to erosion. The subsurface drainage system also manages the soil moisture content. One of the setbacks of this type of drainage system is that it is very expensive to install and manage. 

  • Slope Drainage System

In the Slope drainage system, pipes are installed underground. It makes water move from the building on a downward slope. Hence, slope drains allow water to flow through a pipe on a downward slope. These pipes are usually either constructed with plastic, steel or concrete. The pipes are always protected so there won’t be casualties. 

Slope drainage systems save the cost of installation. It also saves installation time and thereby helps the land owner to save some costs that would have been accrued in construction. A slope drainage system also reduces the need for maintenance since it is very efficient. Hence, the slope drainage system creates a self-cleaning effect. As the water travels down the drainage channel, the water carries along with it stones, dirt and other elements that had accumulated due to the absence of rain. It is the slope drainage system that makes this possible. Therefore, a slope drainage system reduces the need for cleaning and care. Another strong suit of slope drainage systems is that it is not expensive to construct. During a rainy day, the slope drainage controls the flow of the rainwater.

  • Surface Drainage System 

A surface drainage system is a drainage system that is suitable for flat land. When the Land is flat, rainwater could accumulate on the flat surfaces and then lead to water pooling which can be of danger to the building if there is no appropriate drainage system. 

Surface drainage systems can be used as a walkway and even a driveway. If you want to construct a surface drainage system, all you need to do is to dig a few ditches which would in turn serve as a funnel for the excess water. These ditches send water from the land surface thereby preventing flooding. 

In the construction of a surface drainage system, the ditches are dug to serve as a canal for the water to flow through. This prevents flooding. The different types of surface drainage systems include open drains, hollows and humps.