The scene of the crime, variously referred to as the Ogunpa Forest Reserve, the Ogunpa Dam Forest Reserve and the Forest Reserve surrounding Agodi Gardens in Ibadan, is located on the steep slopes of Premier Hotel Hill and the valley surrounding it, as far as Ajibade Street off the main Oyo Road, and Dejo Oyelese Street in Old Bodija.
The valley, which is a major flood plain for the notorious Ogunpa River, extends as far as Secretariat Road, and is bordered by the gentle rise towards the Oyo State Fire Brigade Department and the Oyo State Government Secretariat on the same side as Agodi Gardens, and the University College Hospital opposite.
The Ogunpa River, with its source in Ashi village in Ibadan, and infamously known for its extremely destructive, high-velocity flash floods during torrential rainfall, meanders through the valley, flanked by its flood fringe which extends into Agodi Gardens, on its journey past Dejo Oyelese and Francis Okediji streets and beyond, and empties into the Agodi Lake.
A second smaller river, the Onireke, passes under the Secretariat Road in front of the entrance to the OYS Fire Brigade Department and flows within Agodi Gardens parallel to Secretariat Road until it too empties into the Agodi Lake.
This waterway which is also supplied by pure filtrated water from the underlying bedrock is better known to us environmentalists as the Dandaru Tributary.
Several years ago, when it was noticed that the Ogunpa River had a nasty habit of flowing over the lower stretches of the road that climbs up to Premier Hill, each time it rained, a miniature dam was constructed across the river, close to the junction of the Secretariat and Premier Hill roads. Thus, creating the Agodi Lake.
A deep trench was dug and lined with high concrete walls, which passed in front of the Cultural Centre at the bottom of Premier/Mokola Hill and under the road connecting Mokola to UCH.
Through this trench, the Ogunpa River flows downstream through a vast swathe of Ibadan, before it empties into the Ona River on the left-hand side of the Lagos-Ibadan Expressway, about a 10-minute drive away from Toll Gate, Ibadan.
It is important to keep the proximity of the confluence of the Ogunpa and Ona rivers to Ibadan City in mind, because during the 1980 flood disaster, the turbulent Ogunpa River rushed headlong into the Ona River, causing the two rivers to overflow their banks as they passed through Ibadan.
However, the deep concrete walled trench beginning at the overflow point of the Agodi Lake, followed the Ogunpa River only so far, and the rest of the river’s winding journey had ample scope for flooding it’s banks, as it squeezed between poorly planned open markets and slum neighbourhoods, which have no provision for waste disposal, apart from large scale dumping of refuse into the Ogunpa River as it flowed past.
So, from time to time, during the rainy seasons, the Ogunpa River hemmed in by badly planned neighbourhoods built too close to the river, completely devoid of any flood protecting vegetation, and barely able to breathe through the weight of the refuse in it, would do what any self-respecting river would do under the circumstances.
It would burst its banks, roaring through the City of Ibadan at tremendous speed, and destroy everything in its path.
After a few of these devastating seasonal episodes, the World Bank funded Channelisation Project was drawn up and implemented.
So far, even during heavy downpours, these deep, considerably widened, concrete-lined channels have been able to keep the roaring, turbulent Ogunpa River in check, as it rushes through the city of Ibadan.
However, in the last few weeks, during the first rainy season since the murder of the Ogunpa Forest Reserve, the narrative seems to be changing.
Environmentalists and urban planners alike are starting to get apprehensive over the increase in the number of flooding events in Ibadan, in which two people have died and two are still missing.
And although these seem to have mostly affected the neighborhoods along various tributaries of the Ona River, which has also been extensively widened and channelised, we are keeping in mind the close relationship between the two rivers, and their combined effort in the 1980 flood disaster.
Whatever disturbs the aggressive Ogunpa River will certainly have an impact on the Ona River.
To me it is quite significant that despite the extensive channelisation of both rivers, sections of which were being built with great haste all through the day and night to have them completed in time before the rains started, the volume of water in each river is higher than one would expect.
The concrete-banked channels are considerably wider than the original rivers. The quantity of refuse being dumped in them this year is roughly the same as last year.
We haven’t experienced any heavy, sustained rainfall this year, that has lasted more than, say, five hours. The ONLY variable that has changed is the important flood buffer for the Ogunpa River: the forest protecting the watershed within the Ogunpa Forest Reserve surrounding Agodi Gardens no longer exists.
Now that you have a broader picture of the beginning and the ending of the Ogunpa River, what it does in-between, and how it usually behaves when it is choked and over-full, let us see in Parts 2 and 3 of this story, how the Ogunpa River could react to one of the most monstrous environmental crimes in the City of Ibadan.
First, let me quickly point out that when the Ogunpa River Channelisation Project was first initiated, I doubt that anyone could have foreseen that just a few years down the road, a major watershed for the Ogunpa River would be destroyed and plans made to sand-fill and build on its immense flood plain.
Since this unprecedented and catastrophic event was not considered by the architects of the Ogunpa Channelisation programme, one can only hope that what they have put in place can stand up to the altered behavior of the Ogunpa River, now bereft of both functioning watershed and floodplain.
Especially at a time when global warming and the ensuing climate change is causing unpredictable weather patterns all over the globe.
If unprecedented weather patterns can cause the Sahara Desert to flood, as dry and as hot as it is, what will happen to those of us in the city of Ibadan with its normally high rainfall, now that our flood buffers have been deliberately removed and our landscapes desertified?
By Rosalie Ann Modder-Oyefeso, on behalf of The Save Our Green Spaces Group and The Ogunpa Forest Reserve Team
To be continued