Amid prediction of heavy rainfall, the Lagos State Government has alerted residents, particularly those in flood plains, over the systemic release of water from Oyan Dam by the Ogun Osun River Basin Authority (OORBDA).
The state called on them to relocate to higher and safer grounds to prevent possible loss of lives and properties.
At a media briefing in Alausa, Ikeja, on Thursday, the state Commissioner for the Environment and Water Resources, Barrister Tokunbo Wahab said that OORBDA, acknowledged the concerns raised regarding the ongoing water release from the Oyan Dam and its impact on surrounding communities, particularly those along the Ogun River water channels extending into Lagos State.
He explained that OORBDA operates the Oyan Dam in strict compliance with safety protocols to prevent structural damage to the dam and mitigate flood risks.
Wahab noted that it was crucial to understand that the dam’s annual operations are informed by real-time hydrological data, rainfall predictions from the Nigerian Meteorological Agency, NIMET, and flood outlooks from the Nigeria Hydrological Services Agency (NIHSA).
“These sources guide the water release decisions, ensuring both flood control and the integrity of the dam”, he said.
As detailed in the latest operational report by OORBDA, the total water released from the dam this year, as of 12 October 2024, stands at 1,484.2 million cubic meters (mcm). This remains below the average synthesized annual flow volume of 1,770 mcm.
“Although rainfall across the Oyan River catchment area has been significant, with a cumulative 984.1 mm recorded this year, it remains lower than last year’s 1,540.8 mm and is within safe operational levels.
“The dam is equipped with four radial gates capable of releasing up to 2,271 cubic meters per second (m³/s) during peak periods.
“However, current releases are measured at 208 m³/s, with only two gates opened at 12 per cent capacity each, ensuring controlled and steady discharge.
“Notably, 62.1 per cent of the dam’s flood control capacity remains intact, meaning the Oyan Dam is not under any imminent threat of releasing excess water beyond safe limits. This has been the collaboration of the State with OORBDA.
“Nevertheless, as a responsible State Government, we fully recognize the challenges faced by residents in affected communities, including: Kara, Mile 12, Agiliti, Ikosi Ketu, Owode, Ajegunle, and Odo-Ogun as reported”, he stated.
Wahab stressed that while the flooding experienced in the areas has often been attributed solely to water released from the Oyan Dam, “this is not entirely the case.
“In reality, the downstream section of the Ogun River is influenced by a complex network of over 52 tributaries, all of which converge and contribute to rising water levels in the affected areas.
“These tributaries, combined with rain-induced runoff, significantly exacerbate the flood situation. This is a critical point to consider when addressing flood management strategies for this region.
“In an effort to reduce the flood risks and ensure the free flow of water, OORBDA flagged off the dredging of the Ogun River downstream from the Ikorodu to Isheri axis on Friday, 13 September 2024.
“This dredging project is a proactive measure to deepen the river channel and increase its capacity to convey water, thereby reducing the likelihood of flooding during periods of high inflow”.
Meanwhile, Wahab, disclosed that the State had earlier carried out dredging maintenance in the following locations, namely: Ajelogo, Owode-Elede, Ajegunle, and under deck-on-pile of Itowolo Bridge in anticipation of water release by OORBDA.
In addition, some right-of-ways along the catchment areas were protected and restored.
To effectively contain flooding in the state, he stated, “We are determined to maintain the long-established synergy and partnership with OORBDA, which has ensured control and monitoring of the steady and systematic release of water from Oyan Dam to prevent flooding of the downstream communities. This is a mutual relationship which we cherish, and we shall continue to sustain.
“Lagos State Government will continue to monitor the situation closely and collaborate with relevant Agencies and affected communities, to address humanitarian concerns, particularly for vulnerable groups like women, children, the elderly, and people living with disabilities”.
Wahab continued: “We urge Lagosians who reside along flood plains of major rivers and drainage channels to always be on the alert and be ready to relocate to higher grounds when the need arises.
“Meanwhile, the Emergency Flood Abatement Gang under Drainage Maintenance Department of the Ministry have been consistently de-silting and working on secondary collectors and conduits, to enable them discharge efficiently and act as retention basins.
“To our people, we sincerely appeal that they should desist from acts that can lead to flooding. They should stop indiscriminate dumping of refuse in unauthorized places, throwing pet bottles on the roads, clogging of drains with silt or construction materials, erecting building structures within and around drainage Right of Ways/setbacks, stop discharging human waste into drains/canals which encourages high siltation and vegetal growth that easily clogs our canals as these acts impede the free flow of water”.
The commissioner, therefore, urged residents to report cases of drainage blockages, dumping of waste into canals and other unauthorized places to state Resident Engineers offices statewide in all 20 Local Government Areas and 37 Local Council Development Areas to attend to all needs.
Wahab, also appealed to people to support efforts by complementing the State Government through regular clearing of drains in their frontages to ensure free-flow of storm water as well as to desist from dumping of refuse into drainage channels and roads.
