Fig 1: Sokoto – Zamfara road

As this month (September) marks one of the months (from July to October) that falls in the rainy season in Nigeria, control of  overflow and prevention of flooding always pose serious concerns both to the government and the individuals during this period.  As one of my plans for this month, I determined to carry out careful evaluation of the causes and the existing measures to prevent flooding in Sokoto State, Nigeria. Currently, the average rainfall in the State is about 160mm which is an extremely high record. This has made some roads unmotorable and many areas are waterlogged, thereby making movement difficult in some parts of the State.

Flooding is simply defined as the accumulation or an overflow of water onto a normally dry land. Flooding has been long identified as a common natural disaster and occurs mostly during rainfall. Recently, the heavy rainfall in Kerala, India from 14th to 17th August, 2018   which resulted flooding was reported to have claimed about three-hundred (300) lives.

Sokoto State, one of the States in the North-Western part of Nigeria, always experience flooding during rainy season which have claimed  lives and destroyed property. This gave me a deep concern and eventually decided to embark on environmental survey and evaluation on the State to know the cause(s) of constant flooding in the state. After successful survey I was able to discover the two major reasons for constant flooding. They are;

i.                    Lack of Proper Drainage System

Most of the tarred roads in Sokoto were constructed without drainage. During rainfall, runoff from the road, instead to be collected and drained, flows down to the surrounding areas and accumulates which eventually result to flooding. The few roads that are constructed with drainage system are poorly constructed as there is no main drain that collectively receives the excess water for proper discharge. This has therefore led to the accumulation of water on the road sides and areas close to the road. The importance of proper drainage system can never be over-emphasised. As rainfall increases the amount of water on the land, proper drainage system helps to remove excess water to prevent erosion and flooding. 

Fig 2: Run-off from road accumulated near a school building

Fig 3:  A drain releasing water into a street from the other end

Excess water on the road that could not be drained off by gravity remains there until it is completely evaporated. Prolong stay of water on road surface weakens the road and may eventually lead to road failure. The appearance of excess water indicates poor road construction and improper drainage system.

Fig 4: Excess water still appear on the road after the rain has subsided 5 hours before the picture was taken

ii.                  Poor Urban Planning and Housing

Poor Urban planning and housing in some parts of Sokoto State has also been discovered to be another major reason for flooding. Most of the houses and buildings outside the state capital are built without a building plan. Some houses are built just on the waterway but because the construction of the building was done during dry season it was unknown to them. Also, many houses were built without considering the direction of flow of water, thereby obstructing the passage of water which results to accumulation and flooding.

Fig. 5:  A waterlogged street

As one of the natural disasters, flooding cannot be prevented but its volume can be controlled and impact minimised by proper environmental management. At this age, we shouldn't be massively losing life and property to flooding if we (government and individuals) play our role. Improving our environment is call we must all collectively respond to.

If the residents and government of Sokoto State, Nigeria can jointly tackle these causes of constant flooding I have discovered and highlighted, I believe the impact of flooding in the state would greatly reduce.