Menu

A case for dredging the Nigerian waterways 16 Mar 2022

According to GeoForm International, the leading manufacturer of dredging and sediment removal equipment, dredging refers to the process of removing accumulated sediment from the bottom or banks of bodies of water, including rivers, lakes, or streams. Sedimentation, like from soil erosion or decomposition of plants and animals, is a naturally occurring phenomenon where silt, sand and other forms of insoluble particles accumulate at the bottom of water bodies overtime.

Human beings depend on water bodies and waterways for several daily activities especially the transportation of goods, fishing and recreation. Overtime, the waterways can become clogged with sediments that make navigation difficult, sometimes posing environmental threats of various types. The US Environmental Protection Agency (EPA) lists sediments as the most common pollutant in rivers, streams, lakes and reservoirs.

Dredging has a long history and, it has evolved with human civilization. From the ancient time, people, materials and commodities have been transported by water using various types and sizes of carriers. But the ability to ship people and goods via inland waterways and oceans was, and still is, largely dependent on water depth. As the natural phenomena of siltation and sedimentation threaten the navigational depth of rivers and their deltas, people constantly fight a battle against them. For many centuries, this battle was fought by hand, by simply digging up the mud.

In the 15th century, international trade started to gather pace. As ports became more important and ships became larger, new dredging methods were developed. Primitive bed levelers such as the famous ‘Zealand Scratcher’ were used in access channels of ports. These dredgers scratched the river or seabed, so that the current could pick up the sediment and flush it away.

Around 1575, mud mills arrived on the scene. This type of dredger was used for digging in ports and consisted of a rotating chain with wooden boards to dig up the mud. Then came the steam-engine driven bucket dredger, which didn’t stay for long as it wasn’t quite reliable and effective. This was followed by the suction dredger built by the Americans in the year 1857. It was highly effective but it sank a year later in 1858 while working on the Charleston River.

Over the following years, major dredgers followed the workings of the suction dredger, improving on the first one designed. In 1867, a French engineer named Henri-Émile Bazin designed the dredger that was used to construct the Suez Canal. From then on, dredging by suction became more and more common.

The “cutter suction dredger” would later make its appearance in the 19th century. It was developed in order to overcome the limitations of the mere suction dredgers that were unable to deal with harder soils. The ‘trailing suction hopper dredger’ found acceptance all over the world after its debut in the 1960’s. It became the perfect answer as it was able to continue dredging without hindering shipping traffic.

Recent evolutions in dredging have focused on optimizing the dredging process. Developments include more powerful dredge pumps, standardization of dredgers and equipment, and advanced control and monitoring systems.  

At present, apart from the bad access roads to the ports, one of the major reasons why clearing of goods at the Nigerian ports have become herculean is due to the slow pace in the berthing of ships and offloading of goods from the vessels on arrival. This is as a result of the narrow pathways along the inland waters and the shallowness in depth of same, which restrict navigation to only vessels weighing 11,000 tons and below. This means that the Lagos ports cannot berth a mother vessel.

A recent research on finding a fast and efficient mode of delivering petrochemical products on a mother vessel into the Lagos ports found that the fastest way was for it to berth at Ghana, Lome or Cotonou ports. Onward delivery would then require the hiring of ship-to-ship (STS) vessels to offload the goods from the mother vessel and ship the cargo to Lagos. The vessels would make several trips back and forth the mother vessel until it is fully emptied of its cargo. The reason for this costly and laborious process is that the depth of the waters along the access points to the Nigerian ports do not go beyond 6.5 metres on an average. This depth cannot carry a loaded mother vessel.

The Lagos ports will need at least 11.5 – 12 metres of depth in order to allow mother vessels to gain access to the ports. This is especially necessary when the port of destination and the terminal to offload the cargoes are in Nigeria. This situation is saddening, and it is preposterous that another port outside the country would be getting the revenue that Nigeria should be getting. It is a major financial blunder especially by the maritime stakeholders who have slept on the opportunity to address this unacceptable situation. The government on its part has, unsurprisingly, dosed off at the wheels, failing to ensure that the country is able to maximise its potential to increase the contribution of the maritime industry to country’s GDP.

The last time the Nigerian waterways were dredged in any comprehensive way was between 2009 and 2016. The project cost was N36 billion. The dredging contract covered the lower Niger River from Baro in Niger State to Warri, Delta State, with removal of silt covering a distance of 572 km. With this, only the neighbouring waterways around Calabar, Onne and Warri ports can actually receive large mother vessels, but they still cannot berth along the berthing lines of the said ports.

The Lagos ports are the busiest ports in Nigeria, having about 60 percent of the warehouses and terminals for receiving goods. For this reason, the efforts need to be made to address the deficiencies in the operations and maintenance of the ports.

The need for the dredging of the Lagos ports’ channels is immediate – if not overdue. Without this, the port terminal operators, the seaports, and every other service provider will continue to suffer immensely due to the limitations in the services that they could possibly provide. The financial and job opportunity losses in this scenario are quite considerable.

The country’s maritime industry is underperforming because of the lack of regular and adequate maintenance of the country’s waterways. Besides navigation, the advantages accruable from continuous dredging of Nigeria’s waterways include curtailment of seasonal flooding, one of which ravaged 27 out of the 36 states of the country in 2018, leaving displacement of households, destruction and death of scores of citizens in its trail. Maintaining the waterways is also critical for livelihood and welfare of Nigerians.

Joy Dimka is a Legal Officer at the Nigerian Shippers’ Council.