Pre-Feasibility Study of the Weija Dam and Reservoir in Ghana

Dams are crucial for the watermanagement in Ghana. So the maintenance of these dams and management of the catchments behind them is important too. The NWB Fund supported a study on improving the Weija dam and catchment. This can serve as an example for other dams in Ghana.

Partners and stakeholders

The study was conducted by the Water Resources Commission and Ghana Water Company, with financial support from the NWB Fund, Blue Deal and WaterWorX. Local stakeholders, including traditional authorities and communities, are also key actors in addressing the issues.

The Weija dam

A pre-feasibility study was launched in 2023 to assess the current state of the Weija Dam, its reservoir, and the surrounding catchment area. The dam is a critical water source, supplying about 80% of drinking water to Accra, Ghana’s capital, and nearby regions. The study aims to identify major challenges, propose solutions, and outline next steps for improving water security and dam safety.

The Weija Dam is located on the Densu River in Ghana. It supports Accra’s main water treatment plant and plays a vital role in the country’s water supply system.

Landbouw en veiligheid

Ghana’s economy relies heavily on agriculture, which depends on reliable water resources. However, the Weija Dam faces severe problems that threaten water availability, quality, and public safety. These issues include:

• Sedimentation reducing reservoir capacity

• Poor water quality due to pollution and invasive species

• Flooding risks from excess water discharge during rainy seasons

• Dam safety concerns, as the last structural assessment was in 2018

Population growth and human activities such as illegal mining, deforestation, and poor sanitation in the buffer zone are worsening these problems. Without intervention, Accra’s water supply and community safety are at risk.

Study step by step

The study gathered all available data on the dam and its catchment, mapped key problems, and recommended actions, including:

• Dredging to remove sediment and restore reservoir capacity

• Buffer zone restoration through reforestation and land-use control

• Enhanced water quality monitoring along tributaries and pollution hotspots

• Sanitation improvements in critical areas like Nsawam

• Dam safety assessment to ensure compliance with standards

• Stakeholder engagement and enforcement to protect restored areas and involve communities in sustainable solutions

The study estimated the costs of these proposed actions so that potential investors can be contacted for possible financing options. The study also aims to replicate this approach for other dams in Ghana, fostering intergovernmental collaboration and shared solutions.

Conclusion

The Weija Dam is essential for Accra’s water supply but faces escalating challenges from sedimentation, pollution, and structural risks. Immediate measures such as dredging, buffer zone rehabilitation, improved monitoring, and sanitation upgrades are crucial to safeguard water availability and public safety. Active participation from local communities and authorities will be key to success.