A LAGOS based civil engineer, Engr Afolabi Adedeji gave other reasons for the deterioration of the Expressway and why it is always flooded even at the slightest rain..

“Lagos is a very low lying State, relatively flat in topography, near the Coast, (Atlantic Ocean) and is served by many Rivers as well as Lagoons. Under normal circumstances, when water is to flow by natural means, (that is under the force of gravity), it does so from a higher level to a lower level.

•Engr. Adedeji

It requires only a little stretch of the imagination for even a non-technical person to then appreciate that the steeper the gradient (upward slope) the better the chances of excess water after a heavy rain to flow away through the drains, channels and canals into the sea/ocean,” he said.

Most people in Lagos, according to Engr Adedeji, dump refuse into the drains, which sometimes do not get cleared as often as they should. “Also people construct buildings along natural drainage routes and on flood plains.

Many Nigerian roads have challenges of poor materials utilised for construction, poor design as well as poor supervision of construction on site.

The conclusion is not too hard to seek on why Apapa – Oshodi Expressway (and other roads in Lagos) often become flooded and impassable,” he said.

Asphaltic surfaced roads

Apart from these factors, Engr Adedeji noted that “roads, especially tarred roads, asphaltic surfaced roads or macadamized roads often get damaged from bottom to the top, especially when poorly drained water seeps into them after heavy rainfall, which has the effect of shortening their life span”.

Bad portion of road at Onireke bus stop along Lagos-Badagry express way. Photo by Lamidi Bamidele

”In other parts of the world like the Netherlands where some areas are actually below sea – level, they have learnt over the centuries to fight the problem of flooding.

In fact the Dutch Engineers are reputed to be amongst the best in Water, Drainage, Hydraulics and Hydrological Engineering, anywhere in the World,” he said, and advised that “Engineers in Lagos State Ministry of Works and Infrastructure, the Lagos State Public Works Agency, as well as the Lagos State Field Headquarters of the Federal Highways Department, should under study these Dutch Engineers in Holland.

Better still, bring in some Dutch Drainage experts to Nigeria from time to time for ‘skill sharing’ with their Nigerian counterparts”.

The Lagos-based engineer advocated better construction and supervision of our roads. “There should be regular maintenance, especially the clearing of side drains along our roads of refuse and silt, including empty sachets of ‘pure water’.

He also canvassed the enforcement of better parking control especially for trailers and heavy duty vehicles along Apapa – Oshodi Expressway.

Also reacting to the bad state of Lagos roads and the attendant flooding, a Lagos -based Architect, Arc Emeka Izuwa called for early warning signals by the relevant agencies so that people will stay in safe havens.

He also stressed the need for an efficient drainage system and coordinated urban planning and development. With development in climate studies, rainfall patterns can be detected months ahead of time.

Aeronautic purposes

A lot of that Sunday’s casualties could have been prevented if they had stayed in safe havens away from the flood. Climate watch is no longer just for aeronautic purposes; there ought to have been some large scale warning prior the torrential downpour.

The nation’s Meteorological station should alert the public and private media when rainfall patterns exceed normal levels,” he said.

Arc Izuwah noted that “since a substantial part of Lagos is reclaimed land sometimes even lower than sea level, an extremely efficient drainage and canal system is needed to keep the city flood free”.

“Drains must be cleaned periodically as in some areas blocked drains and canals led to flooded roads. The use of plastics and polythene as product wraps may need to be reviewed as these are the worst culprits.

While canals may be open due to their width, side drains and gutters must have removable pre-cast concrete or steel covers as some of the victims of that Sunday’s flood, not being conversant with the terrain, fell inside drains and were swept away to an avoidable death or damage for cars,” he lamented.

He called for coordinated urban planning and development of the city. “The lack of efficient development control has become the undoing of many city dwellers.

While government insists on the payment of capital development fees prior to building plan approval, it fails woefully to provide any form of infrastructure for most new suburbs before people start building with the result that there is no defined finished road level to benchmark adjoining property development nor drains to discharge runoff water resulting in flooding.

This eventually led to ingress of flood water where the entrance level of the house is close to the adjoining street level when flooding occurs. Government should expedite action in this regard to prevent further disasters,” he said

A former chairman, Nigerian Institute of Town Planners (NITP) Lagos State Branch and Vice President, Association of Town Planning Consultants of Nigeria (ATOPCON).

Obalende under bridge, Ikoyi, Lagos remains flooded. Photo by Lamidi Bamidele

Mr. Moses Ogunleye regretted that the Federal Government has neglected Lagos in terms of infrastructure development, particularly the highways such as Oshodi/Apapa Expressway, Lagos/Ibadan Expressway and Lagos/Abeokuta Expressway.

He noted that because of neglect of Oshodi/Apapa Expressway has continued to suffer colossal damage and this damage has been aggravated by defective drainage facility.

‘The Federal Government has not given emphasis to maintenance of Oshodi/Apapa Expressway. The critical element of the required maintenance is the storm water channels which are non-existence.

Diversion of water

• TPL Moses Ogunleye

‘However, because of urbanization, the drains that were provided for the roads have become inadequate and there have not been expansion programme for them. Most channels on both sides of the highway are heavily silted.

This has led to diversion of water to the road surface which causes continuous damage to the road. Let there be regular maintenance, clearing of drains and resurfacing of the road where necessary’, Mr. Ogunleye said.

The ATOPCON vice president decried the dumping of solid wastes into the drainage channels across the city, pointing out that the situation has become so bad that while it is raining, people come out to toss their refuse into the flowing water body. According to him, no matter the level of government’s preparedness at tackling flooding, such practices will continue to negate its goals.

“There is the need to let people know that they have to change their orientation towards waste disposal. There should be enlightenment campaign to this effect. Drainage design can be changed in some heavily built areas of the city to meet disposal needs of the people. There could be open drains and covered drains to serve different areas of the metropolis”, he explained.