Inside Namdeb’s Seawall Innovation

Between the powerful waves of the Atlantic Ocean and the diamond-rich southern coast of Namibia stands an impressive man-made structure known as the Namdeb seawall. At Namdeb’s Southern Coastal Mines, the mining process begins with accreting beaches. By depositing sand from overburden, the shoreline is pushed back to create minable areas. Standing at seven to ten metres tall, the seawalls are constructed on these newly created beaches to act as a barrier that enables continuous and uninterrupted coastal mining in all sea conditions.

Namdeb has spent years refining the design and purpose of the seawall, ensuring that it is strong and fit for the dynamic and often unpredictable environment in which it stands. The seawall has over the years evolved from a simple structure into a sophisticated system that depends on accurate data, smart planning and constant monitoring.

Amongst the teams ensuring structural stability, Namdeb’s dedicated team of surveyors is working tirelessly behind the scenes to keep this barrier functional, safe and smart. Before any section of the seawall is built, Namdeb’s surveying team gets to work by collecting detailed data along the shoreline, focusing on a key marker known as the +2 metre contour line, which helps to indicate how much land has been successfully accreted and what space is safe to mine. In addition, bathymetric surveys are conducted to map the seafloor’s shape and slope beneath the water’s surface. This combined information is used to create a full coastal profile, extending from the deep sea to the shore.

These datasets are shared with external coastal engineers, who assess the risk and confirm whether the planned seawall section is safe to construct. Once approved, the surveyors go back into the field, staking out construction boundaries, conducting regular spot checks and verifying that the build matches the design. The construction of the seawall is merely the beginning. The real challenge lies in making sure the structure can withstand the force of nature over time.

In 2018, Namdeb experienced a significant breach in parts of its seawall. A breach occurs when the protective barrier is compromised, allowing seawater to penetrate and cause flooding or structural damage to the mining area. This incident became a significant turning point for the company, prompting a thorough review of the seawall design and fuelling more innovative solutions. In response, Namdeb implemented key design improvements, most notably setting the wall 20 metres further back from the high-water line and raising it by two metres. This strategic change ensured that incoming waves break further away from the wall, reducing direct impact and minimising the risk of erosion and future breaches.