Urban flooding is a recurring issue in many African cities. They are a manmade occurrence caused by rapid development, poor drainage, poor urban planning, shrinking open spaces, climate change, and plastic. These contribute to an accumulation of water after rainfall causing property damage and human casualties. Just a few hours of heavy rain washes away access to roads, and sewage and other effluents go on to cause waterborne diseases. In slum areas, urban flooding can be especially catastrophic and deadly.
The accumulation of plastic waste in particular leads to a rise in upstream water levels contributing heavily to urban flood risk. They cause faster blockage than general organic matter because they have a higher blockage density. Once plastic pollution finds its way into the water system it accumulates in hydraulic infrastructures (such as rack structures, dams, distribution and irrigation channels, supply systems, sewerage, and desalination), leading to the clogging of drainage systems.
Bukavu, eastern Democratic Republic of Congo is turning plastic into profit
The city of Bukavu in the Democratic Republic of Congo shuts down for months at a time when the massive number of plastic bottles that end up in the Ruzizi River clog the hydropower station’s turbines, plunging the city into darkness.
The mayor of the city, Meschac Bilubi Ulengabo, told Reuters that Bukavu has no proper dumpsite for its 1.6 million residents. But local and entrepreneur, Elie Mapenzi Matabaro, is turning plastic pollution into a profitable opportunity. His company, FDA group, is turning plastic waste into paving slabs for the city; providing jobs and environmental protection.
He is transforming plastic bottles and waste into affordable and durable paving slabs. “There was no system for the protection of the environment. We started our business to help resolve the waste problem,” he told the publication.
Matabaro and his trash collectors transport huge plastic deposits to the factory where they are melted and poured into hexagonal metal moulds. After a time and once the plastic has cooled, it is tapped out, piled high, and sold.
Benefits of plastic paving stones
Plastic building materials are durable; they do not split, break or deteriorate. Compared to asphalt which lasts between 8 to 15years or concrete which lasts 2 to 25 years, plastic paving is indestructible. Their longevity makes them a solid investment and through recycling the cost of production as seen in Bukavu can be very low.
Environmentally, there is an obvious benefit in reducing plastics in dumpsites and littered around our environment, ruining ecosystems and endangering wild and aquatic life. There is also the benefit of curbing the challenges caused by urban flooding.
But plastic paving also allows water to soak into the ground, unlike current impervious surfaces. This slows water and helps prevent runoff. It can also be used to divert water which would be beneficial for harvesting rainfall.
At a time when the world is battling climate change, start-ups and businesses that are focused on climate action create a business line with strong potential for growth. Construction materials that are both economical and eco-friendly offer advantages in price, innovation, and job creation for waste collectors and recycling operators.