Management and Control of Flood in Nigeria

The recent flooding that has plagued some states in the federation causing devastation, has raised great concern about the nation’s stance towards the management and control of flood in Nigeria. This article takes a critical look at this menace and ways to curb it.

If my memory isn’t failing me yet, it has been raining in my country since the beginning of the year. I can’t even recollect if there was a break at some point. The rainy season this year is one that has been laced with uncertainties as it has gone against the usual weather circle.

As it as been the norm in recent times, the Nigerian Hydrological Service Agency (NHSA), make annual predictions on the outcome of flood in Nigeria and 2016 is no different. Although this flood alert usually takes forever before it gets to the citizenry, and most times, some states would have even experienced the flood before the warnings as the case has been this year.

Flooding in Nigeria occurs at the climax of the rainy season, with the first peak in June, before the August break. Thereafter, the month of September ushers in the second peak when the real devastation is expected.

Hence, the red alert is not just to inform Nigerians about the impending doom but also to ensure that proactive measures are taken by the relevant authorities and communities, such as evacuation of people living in the flood flash points to reduce or curb the menace.

In 2016, NHSA predicts an overflow of the Niger-Benue River basins and other sub-basins, with fears of flooding in the adjoining states.

States at risk include: Niger, Benue, Sokoto, Anambra, Imo, Cross River, Yobe, Ogun, Kebbi, Osun, Zamfara, Katsina, Kwara, Adamawa, Bauchi, Borno, Gombe, Taraba, Kogi, Plateau and Nasarawa. Others are Rivers, Edo, Bayelsa, Delta, Enugu, Lagos, Ondo, Akwa Ibom, Ebonyi, Abia, Jigawa and Kano. With 33 states at risk, I see this as a call to action, because it appears this time around the whole country is in danger of flooding.

One of the most worrisome effects of flood is displacement. This was witnessed last week in Jigawa state, where flood has already killed 18 people and destroyed a whooping 6, 637 houses in about 19 local government areas of the state. Also, farmlands have been destroyed in 24 communities in Niger State.

This indeed is a wake up call to other states that have been declared high-risk areas by NHSA.

Flooding is not only becoming more frequent in Nigeria especially in the cities, it is also becoming more severe and devastating over the decades. However, the increase frequency and severity cannot be attributed to increased rainfall like we’ve had this year. Rather they are in response to an increasing rate of urbanization in the absence of well articulated and comprehensive physical planning and control, which invariably have left many of our coastal cities in flood dilemma.

Proactive and preventive options involving structural and non-structural measures need to be adopted and implemented at curbing the menace of floods.

According to a research work on www.iiste.org the structural measures such as check dams, levees, flood walls and adequate drainage systems will help control periodic inundation in the areas that are liable to flooding in the following ways:

a)The construction of structures for irrigation and the use of excess run-off water for inter-basin transfer as an alternative to absorb excess water from the Cameroons which causes flooding in Benue and some North-Eastern states of the country especially Adamawa state

(b) Check dams will reduce peak flows

(c) Levees and flood walls confine flow within predetermined channels

(d) Adequate drainage systems will reduce peak flow stages of flood and divert excessive flow.

(e) In communities where the rate of flow of storm water is high, embankments should be constructed to breakdown storm water so as not to result into floods. These embankments could be permanent or temporary, such as sandbags placed when a flood is imminent.

However, the adoption of structural measures alone could lead to sub-optimal development of the flood plain and may even invite greater loses when storms occur which exceed the design limits of the structures.

Moreover, structural measures are expensive; hence there is also need to regulate floodplain development with the adoption of non structural measures.

Consequently, the following non structural measures could be adopted to curb the menace of flood in Nigeria.

(i) Floodplain management is seen to be the best approach. In finding solution to flooding using this approach,
the first step is to construct a flood-frequency curve based on historical records and an examination of vegetation to determine how often on average a flood of a certain size occurs in a particular area. Although this approach does not tell exactly when floods will occur, but it gives an insight of how often they might occur based on past history.

From the data obtained, a plan can be developed and applied to:
(a) Prohibit certain types of buildings or activities in flood high risk zones.
(b) Elevate or flood proof buildings that are allowed on the legally defined floodplains.

(c) Construct a flood way that allows water from flood to flow through the community with most minimal or no damage.

(ii) The National Inland Waterways Authority (NIWA) of Nigeria should urgently take steps to de-silt
Water-ways and tributaries which are sited and taken over by shrubs to allow for channels and easy flow of water to curb the ravaging flood in the coastal communities.

(ii1) As is obtained in developed countries of the world particularly in America and Europe, there is always a standing task force that is set up to deal with the problem of snow once winter is approaching. In the same way, the Nigerian government needs to be proactive by setting up standing task force that will tackle the issue of flood once the rainy season is approaching.

(iv) Town planning laws should be properly enforced and strictly adhered to as this will go a long way to
curbing the menace of floods. The Nigerian government should always plan ahead of the population so as to avert the occurrences of unplanned houses and cities.

This is necessary because deviation from the original master plan by prospective town developers do facilitate the occurrence of floods as investigations has shown that a lot of houses built today in Nigeria are erected on natural drainage channels/courses which are often first sand filled by land developers before erecting their structures.

The resultant effect of this practice is that these natural drainage channels/courses having been blocked will afford storm water no channels/courses to pass through and thus the inundation of the areas that are liable to flooding.
(v) All roads should be constructed with adequate drainage facilities provided.
(vi) Drainage systems should be regularly inspected and monitored to take note of any failure with a view of
effecting repairs. Also sedimentation and littering of the drainage systems should be guided against while vegetation like trees whose rooting system tends to or are likely to distort, break or undermine the drainage
system should be removed.
(vii) The immediate downstream culverts which helps to ensure effective runoff discharge and hence effective
self-cleaning of the drainage systems should be de-silted and properly aligned.
(viii) Nigerians should realize that “Action and reaction are equal and opposite”. To this end, they should
properly dispose off their refuse/waste and not into drainage channels as improperly disposed refuse/waste which
comprises discarded plastic, foot-wears, clothes etc. equally block the drains especially at their narrow ends or
points. This equally results to over spill or overflow of the storm water in the drains leading to flooding that can
burst into people’s homes and farms destroying household property and crops.
(ix) Streams, rivers, etc should be channeled by deepening, widening or straightening to allow more rapid
runoff.
(x) There should be adequate sensitization of people who are often affected by flood menace towards adopting
environmental best practices.
(xi) Concerted efforts must be geared towards adequate city planning, policy formulation, enhanced public
enlightenment programmes, integration of environmental planning and education to curriculum of schools at all
levels, capacity building towards adaptation and mitigation of climate change.
(xii) Government at all levels should ensure proper and effective use of ecological fund; and encourage the
integration of environmental disaster insurance to take care of the fall out of flood menace.
(xiii) National disaster and emergency policies should be strengthened to facilitate effective disaster
preparedness and response. This approach will not only save lives and livelihoods, but it will equally reduce
vulnerability to flood menace.
(xiv) Adequate and long-term environmental and natural resource management practices can help to reduce the
risk and vulnerability of people in disaster prone areas.
(xv) There should be collaborations between local communities, NGOs, voluntary groups, local and international donor. Also organizations towards managing floods should be established.
(xvi) Within the realm of professional practice (good land use planning and management) professionals should
undergo training and re-training programmes in related fields (human capacity development) and uphold the
ethics of their profession, particularly avoiding corrupt planning practices that can jeopardize lives and properties
of the people.
(xvii) Dangerous political interventions in land use planning and management should grossly be avoided in
order to protect the occurrence of avoidable flood menace and blaming of innocent professionals

Flood menace have ravaged several towns in Nigeria for several decades leaving in its wake loss of thousands of
lives and tens of billions of naira worth of properties damaged which calls for holistic urgent action on our part
as individuals and that of the government.

The importance of sensitizing government at all levels on the reality of climate change and on possible risk reduction strategies is crucial in preventing flood menace in Nigeria. The need for an effective community based early warning system for flood prevention and control for Nigeria cannot be over emphasized.
There is also the need for government at all levels and its agencies to fund and map out contingency plans and emergency preparedness plans to prevent flood outbreaks crisis in Nigeria.

The 2012 flood which was worsened by the opening of the Lagdo Dam in northern Cameroon by the Cameroonian authorities  remains the most devastating flood incident in post colonial Nigeria and Kogi state was the worst hit by the flood.

PS: The findings about the control and management of flood in this article was culled from www.iiste.org