Riverine management programme to assist with flood control

Agence Française de Développement (AFD) and eThekwini Metropolitan Municipality (EMM) are partnering to improve catchment management in Durban.

Cities and Climate in Africa (CICLIA) – a €12.4 million (R210 million) project preparation facility co-funded by the EU, the Swiss State Secretariat for Economic Affairs (SECO) and managed by AFD – is providing financial support for the City of Durban’s Transformative Riverine Management Programme (TRMP).

“This community-based urban river management system could set an important international precedent for urban river management,” says Geoff Tooley, senior manager: Catchment Management, EMM.

Sihlanzimvelo Stream Cleaning Programme

He explains that the torrential floods that had caused massive damage and loss of life in April had inadvertently assisted with the promotion of the TRMP to industry and residents by showing how the Sihlanzimvelo Stream Cleaning Programme (initiated in 2011), which formed the foundation for the project, had actually helped avoid damage resulting from heavy rains.

“Some 80% of blockages that led to massive infrastructural damage were caused by alien vegetation, with a far smaller portion attributed to build-ups of solid waste such as plastics. Historically, culverts were designed using hydraulic capacity calculations and did not factor in the debris carried by rivers during storm events,” explains Tooley.

Areas managed under the Sihlanzimvelo Stream Cleaning Programme experienced little, if any, damage during the floods.

Sihlanzimvelo employs cooperatives of between eight and ten people from local communities to clear 5 km stretches of river, together with 3 m corridors on either side of the water, of alien vegetation and waste. They also report sewer leaks or blocked manholes.

Durban currently has 105 active coops that report to locally based assessors who are trained to both support these coops and assess their progress according to preagreed requirements. Each cooperative is paid a percentage of the fee due according to an agreed standard of cleanliness and river clearance achieved.

According to Tooley, Sihlanzimvelo had grown its reach from 295 km to 525 km, with ongoing work done in KwaMashu, Inanda, Ntuzuma and Umlazi creating clean public spaces that are now suitable for recreation. Around 800 jobs have been created and Sihlanzimvelo has saved the city millions of rand by preventing additional damage to road culverts and associated infrastructure.

Stream in KwaMashu under the Sihlanzimvelo maintenance programme where solid waste and alien vegetation were removed

Financing

The C40 Cities Finance Facility has supported TRMP for four years. A resulting R8 billion business case and cost-benefit analysis has been done, illustrating how using a similar model to manage the entire 7 400 km of rivers and streams within the city’s boundaries could assist in future.

Future financing for the roll-out of a study and the development of an implementation and partnership plan will now come from CICLIA.

Zoé Ramondou, team project manager: Municipalities and Urban Development at AFD, notes that AFD is happy to support this initiative. “We hope that the study we are funding will deliver very practical tools to facilitate planning and management of these catchments. We look forward to helping demonstrate that nature- and community-based solutions cost less, save a considerable amount of money by preventing damage and managing risk, with the added bonus of positive outcomes within the green economy through job creation. This project will also illustrate how these solutions can be combined with ‘grey’ infrastructure and improve efficiency and sustainability.”

Tooley points out that, in future, residents could expect climate change with hotter temperatures, more rain, rising sea levels and longer dry periods. “So, the flood risk is increased. We are worried that the problems we are seeing today are going to intensify and become more frequent,” he says.

Warmer temperatures would speed up growth of alien vegetation, which is shallow rooted and easily uprooted during storm events. This means more material for blockages of road culverts and more riverbanks exposed for erosion to occur. This increases the amount of silt in rivers.

Tooley notes that this alien vegetation also crowds out the indigenous, slower-growing, deeper-rooted plants. Deeper-rooted plants ensure better bank stability and therefore better protection for the property and infrastructure adjacent to the rivers.

He says that the economic benefits of this project included not only job and business creation, but also the retention of money in local communities, supporting local businesses, as people were able to work closer to home.

Additional project benefits include improved business skills as a result of training, and better community advocacy. Coops are empowered to educate their communities on more appropriate waste disposal as well as increased reporting of illegal dumping. In addition, communities are now growing vegetables on cleared riverbanks. The removal of vegetation has also reduced crime.

“The city has calculated that, if the project was rolled out over the full 1 200 km of rivers and streams crossing municipal land, this would provide an estimated R177 million in benefits to the city (at a cost of R92 million) and create 1 500 jobs. That is conservative. We haven’t even costed in the additional green economy opportunities. What this translates to is that, for every rand that we are spending, we are creating benefits worth R1.92,” explains Tooley.

The next challenge is a roll-out of river management programmes across privately owned and tribal trust land. Research along the Ohlanga River (further extrapolated for the whole city, supported by the C40 CFF funding) revealed that R7.5 billion in public and private investment would be needed over the next 20 years.

“We would multiply that investment by 1.8 to 3 times – and that excludes green economy opportunities,” he adds.

These could include the growing of indigenous vegetation to replace alien vegetation in corridors, recycling and development of new products made from waste collected from rivers.

The next step is to identify partnerships and role players within three spaces – the Umhlangane River catchment, the Palmiet River catchment and the Umhlatuzana River catchment – and to develop on the ground implementation plans that will serve as a blueprint for businesses and property owners to fund cooperatives to clear rivers and streams on privately owned and tribal trust land. It is this important next step that is to be funded by the latest tranche of funding from CICLIA.

This has the potential to unite communities separated by apartheid-era town planning. “This programme could not only transform rivers but change our society. This will provide a scalable and replicable model for how cities across the world can manage and maintain their waterways while maximising socioeconomic benefits. Ultimately, we want to cover the whole city and the latest funding will enable us to keep this programme running. This is not a one- or two-year project – this is a forever project,” Tooley concludes.

Culvert at Caversham Road blocked with alien vegetation and solid waste during the April 2022 storm Gabions and River Mattresses Gabion Rocks Hexagon Wovenmesh Square Weldmesh Geotextiles Gabion Tool Sets Biodegradable Soil Blankets Soil Bioengineering Sandbags Gabion Barriers