Ogun-Oshun River Basin Authority Managing Director/CEO, Otunba Olufemi Olayemi Odumosu
By Our Reporter
The Ogun-Oshun River Basin Development Authority (Ogun-Oshun RBDA) has released a water forecast from the Oyan Dam for preparedness and mitigation measures for stakeholders’ emergency management in Lagos and Ogun States for flood control.
The Ogun-Oshun RBDA in the forecast released by its Managing Director/CEO, Otunba Olufemi Olayemi Odumosu, stated that the forecasting would empower the residents of low-lying communities to be aware.
It added that it would from May 2023 “be maintaining the releases of an average of 3.0 – 5.0million cubic meters (mcm) per day, so as to further create more space in the Reservoir” and would rise to 9.0 by August and September.
The RBDA added that by November 2023, “our releases would be reduced to about 3.0 – 5.0 million cubic meters (mcm) per day till December 2023 when the Gates may likely be closed for the year 2023.”
Oyan River Dam is one of the two multipurpose dams within the purview of the Ogun Oshun River Basin Development Authority as a part of the strategic comprehensive development of the water resources potentials of the Ogun River Basin and its Watershed Management.
It noted that the Dam operation was kick-started by activating the Reservoir desiltation process on February 2, 2023, an action recognized and encouraged in the report submitted by the National Water Resources Institute, Kaduna, after they carried out sedimentation studies on Oyan River Dam in 2017.
According to Ogun-Oshun RBDA, “The Annual Flood Outlook (AFO) for 2023, produced by the Nigeria Hydrological Services Agency (NIHSA) i.e. Soil and Water Assessment Tools (SWAT) generated this year is also sectionalized into three periods within this year calendar termed AMJ – April, May and June, JAS – July, August and September and ON – October and November this is done to improve the accuracy reliability of generated scenarios.
“In this May 2023, we shall be maintaining the Releases of an average of 3.0 – 5.0million cubic meters (mcm) per day, so as to further create more space in the Reservoir. In June 2023, we may increase our Releases to 4.0 – 6.0million cubic meters (mcm) per day, so as to further create more space in the Reservoir while following real time forecast from NiMET for real time response.
“In July 2023, our Releases may be increased to the range of 6.0 – 8.0million cubic meters (mcm) per day. This will create more space for incoming water expected in August 2023. In August 2023, our Releases may be increased to the range of 7.0 – 9.0 million cubic meters (mcm) per day. This will create more space for incoming water expected in September.
“In September 2023, because of the space we would have created in August we shall be maintaining our average Release of 7.0 – 9.0 million cubic meters (mcm) per day. In October 2023, using our last two-year operations from table 2, NIHSA (ON) scenario figure 3 and periodical forecast from NiMET, we shall be maximizing the created space in the Reservoir to impound more water and release it at a controlled average rate of 9.0 – 11.0 million cubic meters (mcm) per day.
“By November 2023, our Releases would be reduced to about 3.0 – 5.0 million cubic meters (mcm) per day till December 2023 when the Gates may likely be closed for the year 2023.”
The Authority noted that it is a known fact that flood is the most devastating natural disaster affecting many regions of the world every year, including Nigeria, and could be catastrophic, especially within its coverage areas, mostly downstream Ogun and Lagos States.
“Therefore, in mitigating the foreseen flooding of this year, downstream of the Oyan Dam, as advised by NiMET in the 2023 Seasonal Climate Prediction (SCP), that updates on 2023 Seasonal Climate Prediction (SCP) will be released regularly to provide people with the latest information on the state of the atmosphere and related issues to enable prompt and decisive actions during the season.
“We recommend that all Stakeholders should always monitor the rain forecasts in their areas so as to have a probable idea of what may likely be the effect on their immediate environment so as to contact appropriate Agencies, in order to save our lives and property.”
It stated that the forecasts for 2023 AFO showed that parts of the local government areas in Ogun and Lagos States fall within the High Flood Risk Areas, the Moderate Flood Risk Areas, Coastal Flooding and the Flash and Urban Flooding will be experienced in their urban cities centres.
“It is therefore on the basis of these predictions that we are in a position to be better prepared for, and respond to potential flood events.
“We have in place Early warning systems such as Flood Alert systems, with Automatic Water Level Recorders and Real-time Hydrometry telemetric water level monitoring.
“In order to avoid flooding this year, like other years, we have proactively commenced Water Releases since February, 2023, in order to create more space for flood control activities.
“By such Public sensitization of Improved Flood Warning Mechanisms, properly conveying advance warnings of impending storms and floods will not only give people the opportunity to be proactive in preventing damage to their property, it will also save lives.”