The great retreat: Can a new law save Ghana’s crumbling coastline?

Across the 550 kilometres of Ghana’s coastline, a slow-motion disaster is unfolding. From the historic forts of the Central Region to the vibrant fishing communities of the East, the Atlantic Ocean is no longer just a neighbor, it is an intruder. Ghana’s shoreline is retreating at an average of two metres per year, but in hotspots like Keta and Ada, the sea has been known to swallow 17 metres of land in a single, catastrophic year.

This is not just a story of rising tides. Ghana is caught in a geomorphological emergency fueled by a century of engineering mistakes and a critical policy lag. This lag represents a dangerous disconnect between modern science and government action. While the global engineering community has moved toward flexible and nature-based defenses, Ghana’s coastal policy has remained frozen in the mid-20th century. For decades, the regulatory framework failed to mandate environmental impact assessments that considered the long-view of the coast. Instead, it favoured a fragmented, firefighting approach—reacting to local cries for help with outdated methods while ignoring the systemic health of the shoreline. However, a recent piece of legislation, the Ghana Hydrological Authority Act of 2022, might finally provide the catalyst needed to bridge this gap and turn the tide.

The science of the drift: Understanding our shoreline

To understand why our current coastal defenses are struggling, we first have to stop viewing Ghana’s beaches as fixed, stationary borders. In reality, our shoreline acts like a massive, invisible conveyor belt driven by the unique geometry of the Atlantic. Because our coast doesn’t run perfectly west-to-east—instead tilting at a slight angle of about 10° to 15°—the powerful swells arriving from the South Atlantic never hit the shore head-on. Instead, they strike at a consistent “sideways” angle of approximately 5° to 10°. This diagonal impact creates a relentless zig-zag motion known as longshore drift, which effectively pushes vast amounts of sand along the beach from the west toward the east in a mechanism known as longshore sediment transport, or littoral drift.

In a healthy, natural system, this constant migration of sand isn’t actually a problem; it’s a perfectly balanced relay race. As the waves wash away sand from one beach, that loss is immediately offset by “new” sand arriving from the west or fresh sediment flowing out from the Volta River and our various coastal lagoons and estuaries. The shoreline stays stable because the “conveyor belt” is always being reloaded with material from these natural sources.

The concrete trap: The transfer problem

The transfer problem occurs when we disrupt this conveyor belt. When we build grey infrastructure—massive rock groynes or seawalls—to protect a specific town, we are essentially building a dam across that sandy conveyor belt.

The rocks trap sand on the updrift side, creating a wide beach for that town. However, on the downdrift side to the east, the conveyor belt continues to move sand away, but there is no new sand arriving to replace it because it is trapped behind the rocks. The ocean, starved of its natural sand supply, begins to eat into the land with terrifying speed, scouring the shore to satisfy its raw energy. By trying to fix the beach in one spot, we simply transfer the destruction to our neighbours.

The Keta Sea Defence Project serves as the ultimate cautionary tale of this phenomenon. While the multi-million dollar project stabilised the shore between Keta and Kedzi, it triggered a disaster for the communities to the east. By trapping sediment, the project caused erosion rates in adjacent areas to spike from 3.2 metres per year to a staggering 17 metres. This creates a vicious cycle where the government spends millions to fix a problem in one area, only to create an even bigger emergency in another, necessitating yet another expensive rock wall.

The coastal squeeze: A livelihood crisis

This engineering failure leads to coastal squeeze. Naturally, a beach or mangrove forest would migrate inland as sea levels rise. But when we build an immovable concrete wall, these habitats have nowhere to go. They become trapped between the rising tide and the hard wall, eventually drowning and disappearing.

In the Ada region, this has led to the destruction of nesting sites for endangered sea turtles and the eradication of the very mangroves that serve as nurseries for the fish that feed the nation. When the mangroves die, the artisanal fishing industry dies with them. We are not just losing land; we are losing food security and heritage sites, which illustrates the irreversible cultural impact of inappropriate infrastructure.

A new philosophy: Nature-Positive Engineering

The research argues for a pivot to Nature-Positive Engineering. This is not just about protecting nature; it is about using nature as a high-performance engineering tool. Nature-based solutions, such as restoring sand dunes, planting mangroves, and protecting seagrasses, act as natural shock absorbers. Unlike a seawall, which is a static object that begins to fail the moment it is finished, a mangrove forest is self-healing. It can actually grow upward in response to rising waters, providing a dynamic defense that concrete can never match.

By shifting to this new paradigm, Ghana can unlock a resilience dividend:

1. Adaptability: While a seawall has a fixed design life and can be overtopped as sea levels rise, natural systems can adapt to changing conditions.
2. Food security and livelihoods: Restored coastlines provide nurseries for fisheries and a foundation for sustainable ecotourism.
3. Climate action: Coastal ecosystems are high-density blue carbon sinks. Protecting them helps Ghana meet its international climate goals under the Paris Agreement.

The legislative catalyst: Act 1085

Historically, coastal protection in Ghana was project-centric, meaning the former Hydrological Services Department (usually under the Ministry of Works and Housing) acted as a service provider reacting to crises one village at a time without the power to regulate bad engineering.

Act 1085 changes the game by transforming that department into an autonomous authority with the statutory power to regulate the entire 550-km coastline. The muscle of this new law will be Legislative Instruments and Regulations governing coastal development and coastal protection in Ghana. These regulations will enforce the following critical pillars:

• Mandatory nature-first assessments: The authority must require a feasibility study for every new project that proves nature-based solutions are technically unfeasible before rock-based structures are even considered.

• Integrated sediment cell management: Instead of village-by-village projects, the authority can manage the coast at a regional scale based on littoral cells. This prevents the transfer problem by ensuring one village’s protection does not become another village’s destruction.

• Cross-sectorial governance and buffer regulation: The law provides a platform to collaborate with the EPA to enforce coastal setbacks and stop unauthorised private constructions that disrupt the natural conveyor belt of sand.

• Regulation of private construction: Providing the authority to stop unauthorised private sea defenses and regulate developments within coastal buffer zones.

The path forward: From debt to investment

It is important to ensure that Act 1085 does not end up as just another law on paper. There is the need for revised engineering guidelines that set nature-based solutions as the default intervention, hybrid infrastructure pilots where minimal hard structures are used temporarily to help natural systems take root, and economic valuation that proves nature-positive approaches are cheaper in the long run.

The message is clear: The Atlantic is coming, but Ghana no longer needs to fight it with a failing 20th-century playbook. By embracing the new act and working with the natural flow of the coast, Ghana can transform coastal protection from a recurring national expense into a long-term investment in its people and its future.

BY SELORM DZAKO ABABIO MSC MPHIL

Keli Engineering Consult Ltd
sdababio@keliconsult.com

Join our WhatsApp Channel now! https://whatsapp.com/channel/0029VbAjG7g3gvWajUAEX12Q

Follow our WhatsApp Channel now! https://whatsapp.com/channel/0029VbAjG7g3gvWajUAEX12Q