GhIE pushes for national runoff control policy to combat urban flooding

The Ghana Institution of Engineering (GhIE) has called for an urgent overhaul of Ghana’s stormwater management policies, warning that the country’s current drainage systems are no longer capable of addressing the realities of rapid urbanisation, climate variability, and increasing flood risks.

The call follows growing evidence that conventional drainage infrastructure, designed primarily to move stormwater downstream as quickly as possible, has become inadequate for modern urban environments, particularly in Accra and other rapidly expanding metropolitan areas.

According to a policy brief presented by the Institution, Ghana’s cities can no longer rely on traditional, centralised, conveyance-based drainage systems.

Rapid urban expansion, widespread paving of land surfaces, poor waste management practices, and increasing rainfall intensity have significantly exceeded the capacity of existing drainage networks.

“Flooding in Accra is no longer simply a seasonal occurrence. It is increasingly becoming a structural challenge driven by rapid urbanisation, the loss of natural infiltration areas, and fragmented management systems,” the policy brief read.

The Institution observed that flooding incidents have become more frequent and severe over the past decade, occurring even during periods of relatively low rainfall. This suggests that the problem extends beyond climate change and reflects deeper weaknesses within existing stormwater management systems.

The Institution highlighted that many drains have effectively become conduits for solid waste, reducing their hydraulic capacity and compromising their intended function.

The policy brief also noted that hydraulic constraints within the Odaw-Korle drainage system continue to contribute to recurring flood events across parts of the capital.

The document further identifies institutional fragmentation as a major obstacle to effective flood management. Responsibilities are spread across multiple agencies, while administrative boundaries often do not align with natural drainage basins, making coordinated, catchment-wide planning difficult.

To address these challenges, GhIE is advocating a transition towards decentralised, nature-based stormwater management systems that mimic natural hydrological processes.

Recommended interventions include permeable pavements, bioswales, rain gardens, green roofs, detention systems, infiltration facilities, riparian buffers, and rainwater harvesting.

The Institution is also calling for a National Post-Development Runoff Control Policy to ensure that new developments do not generate runoff volumes and peak flows beyond pre-development conditions.

In addition, GhIE recommends a National Rainwater Harvesting Policy, stronger enforcement of land-use regulations, the establishment of catchment-based planning units, the protection of waterway buffer zones, and greater private-sector participation in green infrastructure development.

According to GhIE, adopting these measures could significantly reduce the frequency and severity of flooding, improve water quality, lower long-term infrastructure costs, create green jobs, and strengthen Ghana’s resilience to climate change.

“The evidence is clear, Ghana must shift from downstream, conveyance-based engineering to upstream, decentralised, nature-mimicking stormwater management. The time for policy reform is now,” the report stated.

The recommendations align with global best practices in sustainable urban drainage and support the achievement of the United Nations Sustainable Development Goals (SDGs), particularly SDG 6 (Clean Water and Sanitation) and SDG 11 (Sustainable Cities and Communities).