By Yemi Olakitan
Lagos State government has urged people resident in the Ogun River downstream to prepare for massive flooding.
This follows an updated 2023 Water Releases Forecast for Flood Control by the Ogun-Oshun River Basin Authority, effective September, and the high rainfall being experienced as predicted.
A statement by the Permanent Secretary, (Office of Drainage Services and Water Resources), Ministry of the Environment and Water Resources, Lekan Shodeinde, identified the affected areas as Alagbole, Meiran, Maidan, Kara, Isheri-Olowora, Agiliti, Owode-Onirin, Owode-Elede, Agboyi I, Agboyi II, Ajegunle, Itowolo, Majidun, Ibeshe, Baiyeku, Maidan and Lekki-Ajah axis.
According to him, the state is concerned about the safety of lives and property. He, therefore, urged residents of the mentioned areas to move upland.
Shodeinde added that the alert was necessary because there is much water to be expected in September, in addition to the heavy downpours usually associated with the months of September and December every year along the Ogun River Basin and other related predictions and warning from Nigeria Metrological Services (NIMET), Nigeria Hydrological Services (NIHSA), National Emergency Management Agency (NEMA)and other related Agencies.
According to the updated 2023 Water Releases Forecast, signed by Managing Director of the Ogun-Oshun River Basin Authority, Olufemi Odumosu, the comparative total amount of rainfall recorded from January to August 2023 (1,128.6mm) is higher than that of January to August in the year 2021 (713.4mm) and 2022 (848.1mm).
Shodeinde added: “Comparatively, 968.6mm was recorded as amount of rainfall for 2021, 1,140 mm for 2022, while in the first eight months of 2023, a quantum of 1,128.6mm has already been recorded, which means when the remaining four months is factored in, a very high intensity of rainfall would be recorded for the whole year.
“When some of the other figures released by the Ogun- Oshun River Basin Authority is further scrutinised for volume of water spilled, it shows 1,102mcm was spilled in 2021 and 1,475.6 mcm in 2022, while for the first eight months of this year, 1,393,1mcm has already been spilled by the River Basin Authority. This means that more water will be released when factored with the remaining four months in 2023.”
The Permanent Secretary noted that the water levels of all tributaries, including the Oyan Dam, are rising and is one of the contributory factors to the possibility of the likely flooding at downstream flow of Ogun River.
He stressed that the same applies to all the channels and tributaries that discharges into the lagoon, which may experience tidal lock and flow back because of the high water level that prevent discharges, leading to flash flooding.
“Since Oyan River is one of the major tributaries to Ogun River, it is expected that other tributaries will also contribute much to the likely flood downstream flow of Ogun River In mitigating the flood this year, the Ogun-Oshun River Basin Development Authority.
“As at the end of end of August, the Ogun-Oshun River Basin has increased its Daily Releases to 21.4 million cubic meters (mcm) Volume of Water to create more space in order to regulate the expected inflow of water from the Catchment Upstream in September. Water releases might rise to average of 22.0 – 24.0mcm per day, this amount of water that will be released shall depend on rate at which water flows into the reservoir and the height measured in the reservoir”, the statement by the OSRBA added.
On the release of water from the Lagdo Dam in Cameroun to the Benue River, Shodeinde assured residents that only 11 states – Adamawa, Taraba, Benue, Nasarawa, Kogi, Anambra, Edo, Delta, Bayelsa, Rivers and Cross River – will be affected by the releases.
“There is obviously no connection between the Lagdo Dam releases and operations of Oyan Dam and the water releases Forecast for Flood Control in Lagos and Ogun State,” he added.