Akosombo Dam spillage: Evidence of climate pressures
Between September 15 and October, the Volta River Authority (VRA) conducted a "controlled spillage" of water from the Akosombo and Kpong dams.
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This is the eleventh since the inauguration of the Akosombo Dam in 1965.
The spillage submerged communities downstream.
Media reports suggest that about 50,000 people were displaced while homes, farms and livelihoods were washed away.
This created environmental and economic crises, disrupted education and increased hardships for vulnerable individuals.
Also, experts warned of a public health epidemic that could follow the flood disaster.
Generally, the situation is described as a humanitarian crisis.
While the VRA and the National Disaster Management Organisation (NADMO) argue that the spillage was a necessary measure to avert a catastrophic dam rupture, valid questions arise about the process, given its consequences.
It is worth noting that the VRA successfully managed higher water volumes (277 ft in 2010), compared to 276 ft this year.
Furthermore, there are financial and engineering concerns about the cost associated with evacuating and resettling affected communities in modern Ghana, as opposed to employing advanced engineering techniques to divert excess water to the sea.
Despite these important questions, I delve primarily into the factors contributing to fluctuations in water levels in dams like Akosombo, Kpong and Weija, leading to spillage disasters in recent years.
Some flooded communities around the dam
Historical concerns
The operational water levels for the Akosombo dam range between 240.00ft and 278.00ft.
Deviations beyond these limits have serious implications for hydroelectric power supply and human lives.
Historical data, such as research conducted by Eric Ocran in 2015, reveal that the lowest recorded water level occurred in 1966 (234.00ft), while the highest was noted in 2010 (277.54ft).
Although concerns exist regarding both low and high water levels, the prolonged focus has been on the lower values.
This concern was substantiated by Eric Ocran's work in 2015, which indicated a potential fall of levels below 226.00ft, which could cause all the turbines in the dam to shut.
Several researchers raised similar concerns about the declining water volume in the dam.
Beyond that, the Daily Graphic reported on a group of pastors who prayed at the dam site to avert a potential prolonged electrical power shortage due to low water levels.
In recent years, however, the situation has reversed and the dams are overflowing and several factors may be accountable for that.
Some include lower temperatures/evaporation, increased inflows from tributaries and developments along river courses.
Another might be reduced water consumption in the dam due to the construction of the Bui Dam and the installation of thermal plants.
Significant factor
All the factors notwithstanding, a fundamental question could be whether climate variation is a primary contributory factor.
According to the UN's Intergovernmental Panel on Climate Change (IPCC), Climate Change is long-term shifts in temperatures and weather patterns, caused by the prolonged accumulation of carbon dioxide (CO2) emissions in the atmosphere, and results in more frequent and unpredictable extreme weather events.
The National Aeronautics and Space Administration (NASA) supports this perspective through data from observations on ground, air and space, with computer models that change in global land and ocean temperatures, rising sea levels and shifts in extreme weather patterns such as hurricanes, heatwaves, floods and precipitation, which are associated with climate change.
Local impact
In a 2021 study, Frederick Ebert Stiftung found that Ghana experienced extreme weather events over the past five years, including severe droughts and heavy rainfall.
These had devastating effects on agricultural workers and posed significant vulnerabilities to infrastructure, public health and ecosystems.
The World Bank Group's Ghana Country Climate and Development Report 2022 warned of flooding and drought as consequences of climate change in the country and advised the government to establish early warning systems and safety nets for vulnerable communities.
Akosombo case
Analysing the Akosombo Dam's situation reveals a notable surge in water levels to about 276ft.
This is a sharp contrast to the situation in the recent past when the dam was at risk of drying up.
Authorities attribute the surge to heavy rainfall, a claim supported by data from the Ghana Meteorological Agency.
Aside from that, falling temperatures in the region have significantly reduced water loss from the dam due to reduced evaporation.
Case for mitigation
The evidence strongly suggests that the overflowing dams in Ghana are influenced by climate pressures.
Urgent measures are required to mitigate the impact on vulnerable communities.
There is, therefore, the need to invest in AI tools for remote sensing and satellite data for early detection of climate pressures and appropriate responses.
The writer is the Head of Corporate Affairs,
Pentecost University.
E-mail: [email protected]
