Durban’s Transformative Riverine Management strategy unfolds

During 2009, eThekwini Municipality approved the Municipal Adaptation Plan: Health, and Water. One of the items included was the need to “protect and restore riparian vegetation so as to protect the integrity of riverbanks and retain biological buffers against flooding”. This reference acknowledged the need for a renewed focus on preserving eThekwini’s ecological infrastructure to improve the city of Durban’s climate change resilience.

At the same time, the city’s engineering unit was concerned about the high incidence of blockages and damage to culverts within the eThekwini footprint. Investigations revealed that some 70% of the blockages were due to alien vegetation and 30% due to solid waste. The installation of debris walls partially helped to ease the problem. However, this didn’t address the root cause and the need for a more proactive approach was evident.

General cleaning and minor repair maintenance of the city’s culverts and roads vests with the Roads and Stormwater Maintenance (RSWM) Department, while major repairs and maintenance vest with the Coastal, Stormwater and Catchment Management (CSCM) Department.

The issue of blockages had been building for some time and, around 2007, the RSWM and CSCM began to explore ways of tackling the source of alien vegetation and solid waste within eThekwini’s river systems. This led to roundtable discussions with eight city

While engineered infrastructure plays a vital role in stormwater management, the performance of structures can be greatly enhanced by allied environmental interventions. A classic example is the Sihlanzimvelo Stream Cleaning Programme, which has served as the basis for eThekwini’s Transformative Riverine Management Programme (TRMP) Strategy, developed through C40 Cities funding.

By Geoff Tooley*

- cutting back of vegetation

- alien vegetation control departments responsible for various aspects of the stream environments. These comprised: the Environmental Health Department; Department of Water and Sanitation; Durban Solid Waste; RSWM and CSCM; the Department of Parks, Recreation and Culture; the Environmental Planning Department; and the Climate Protection Department.

- planting of indigenous vegetation.

The first prize was to obtain collective interdepartmental funding support for the envisaged programme. However, this proved to be a challenge, so the programme was driven from inception using RSWM funding since the scope fell within the ambit of culvert maintenance.

Initiating Sihlanzimvelo Programme preparation for the Sihlanzimvelo project started in 2009, with work commencing on the ground in November 2011. The length of stream covered initially was 295 km, and later increased to 525 km.

At the onset, the project focused on the Inanda, KwaMashu, Ntuzuma and uMlazi areas, as it was not possible to implement interventions across the whole city. Clean-up programmes are run by city registered cooperatives (coops) employing members from nearby communities. The main tasks of the coops include:

- clearing of culverts and stormwater systems

- minor erosion control of embankments

- ditching to prevent water stagnation

- litter and debris removal and disposal

Each coop is given 5 km of stream to manage. The streams covered have a catchment less than 1 000 ha as this relates to a normal stream depth below knee height. The area of work is the waterway and 3 m either side of the water, with coops also required to report leaking sewers and erosion points.

The state of the coop’s length of stream is assessed each month against a set standard, with the payment scale determined by the level of maintenance achieved.

The business case and C40 CFF funding

The Sihlanzimvelo programme started to produce results and maintenance teams on the ground were recording fewer blockages to culverts, as well as less normally associated damage. These and allied benefits, like unemployment mitigation, caught the attention of city officials and the community, and presented an opportune moment to lobby for more funding to expand the initiative.

Externally, a major boost came with the provision of funding support via the C40 Cities Finance Facility (C40 CFF) for the development of a business case driven by a TRMP implementation strategy document. The business case development process was led by a business case subcommittee formed within eThekwini Municipality.

In terms of background information, the C40 CFF is made up of: the C40 Cities Climate Leadership Group; Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ); the German Federal Ministry for Economic Cooperation and Development (BMZ); the British Department for Business, Energy and Industrial Strategy (BEIS); and the United States Agency for International Development (USAID).

C40 CFF’s primary objectives are:

- to reduce greenhouse gas emissions

- the sustainable financing of urban climate change investment projects

- developing the capacity of city administrations to mobilise and access a broad range of financing instruments

- sharing knowledge of CFF partner cities via peer-to-peer learning

- developing partnerships between cities and investors/financiers and their representations.

TRMP in practice

The TRMP approach is assumed to include an overarching ‘transformative riverine governance’ umbrella implemented by eThekwini Municipality. This provides the necessary framework for facilitating cross-sectoral and multistakeholder collaboration (including with other spheres of government) and creating enabling conditions for riverine management action across all riverine landowners in the city, namely municipal, private and traditional authority.

Biophysical riverine management interventions include both ecological restoration and management at a systems scale, aiming to improve the functionality and resilience of rivers to urban impacts and climate change. The condition and/or management of the built/agricultural landscape surrounding rivers would also be improved due to the minimisation of accelerated stormwater, sediment and pollution loads.

Cost-benefit analysis

Getting to the business case stage required the completion of a complex cost-benefit analysis (CBA) exercise. Land ownership was highlighted as one of the key factors to be considered when developing any programme intervention due to regulation restrictions.

Nine future riverine management scenarios were modelled in the CBA. These included:

- a ‘do nothing’ scenario for municipal, private, and traditional authority land in riverine areas with climate change as a driver of river impacts

- upscaling of the Sihlanzimvelo Stream Cleaning Programme on municipal land in upper catchments with climate change

- a ‘basic management’ scenario for private and traditional authority land in riverine areas with climate change

- ‘transformative management’ scenario for each of the three land ownership types with climate change impacts.

In the CBA, the costs and benefits of implementation of these different riverine management models has been estimated at a city-wide scale. In order to do this, the Ohlanga River Catchment was used, and the results extrapolated across the city.

Key findings

Studies show that many of Durban’s rivers are already severely impacted by urban and agricultural development, and pollution. Due to this, it is estimated that the ecosystem services supplied by these urban rivers are 42% below the theoretical best case and that climate change will degrade these systems further, reducing ecosystem services supply by a further 11% by 2040.

eThekwini will be directly affected, with annual damages to municipal road culverts alone due to increased climate-change-related flooding estimated at over R151 million by 2040. Declining river water quality will affect coastal tourism and property values, as well as the ability of riverine communities to access and use rivers for household water provision, crop irrigation and recreation.

The annual cost implications for the wellbeing of municipal citizens and coastal users are estimated to reach R224 million by 2040. (Only historic damage costs to culverts were available to use in this study and so it is recognised that costs indicated are lower than what will be experienced once all infrastructure damage is totalled.)

The CBAshows that if the city upscaled the existing Sihlanzimvelo programme on municipal land – approximately 1 168 km of river – this would cost the city approximately R92 million annually. The city would experience avoided damage costs to municipal culverts and road crossings of R59 million (this excludes damage to sewers, watermains and other municipal infrastructure). The societal benefits each year are estimated to be R177 million; 234 coops would be needed to do the work, which would create some 1 557 jobs. This translates to R2.60 in benefits for every R1 spent by the city. The additional green economy opportunities in terms of job creation and economic benefits have not been included.

In turn, for a city-wide TRMP, the CBA shows that an investment of R7.5 billion by the public and private sector is required over the next 20 years. This would result in an avoided cost of R1.9 billion in damage to municipal culverts and roads (this excludes damage to sewers, watermains and other municipal infrastructure), R12 billion to R24 billion in societal benefits, greater than 9 000 jobs and many additional green economy opportunities. This translates to R1.80 to R3.40 in benefits for every R1 spent.

Implementation plan

There are a few key aspects that need to be highlighted and which need to be followed for this programme to succeed at the level required to make eThekwini’s TRMP truly transformative. The rest of the details will develop as the various projects evolve and grow.

To work effectively:

• The programme must remain as flexible as possible in order to include every initiative in this space, whether it is a large or small, or short or long duration initiative.

• There needs to be a separation between the three required levels of coordination/ facilitation, the implementing agents/fund managers and on-the-ground implementers.

• There needs to be municipal coordination of the municipal programmes to maximise crosssector benefits.

• There needs to be private sector coordination to maximise cross sector benefits.

• There needs to be coordination between the private and municipal coordination hubs.

• River catchments cross municipal boundaries and so there needs to be coordination between neighbouring municipalities.

• There is no right time to start any initiative –the key is to welcome all initiatives and find a way to co-ordinate the benefits.

• Not all areas of the catchment will be covered in the short term. The key is to start somewhere, identify the gaps and find ways to facilitate the closing of these gaps.

The required funding needs are for:

• Programme management: programme design and CBA, integration, and coordination between municipal functions and with eternal entities, fundraising, research, river management partnerships and institution building, and monitoring and evaluation.

• Riverine infrastructure: grey infrastructure (canals, culverts, gabions, sand and silt removal), ecological infrastructure (riparian tree planting, agro ecology and food gardens, artificial wetlands, weirs, clean-ups) and recreational infrastructure (pocket parks, pedestrian bridges, outdoor gyms and play equipment, lighting, pathways, and benches).

• River management services: Sihlanzimvelo community-based stream cleaning, water quality monitoring and reporting faults in the sewerage system.

• Socio-economic capital: leadership development, community education and capacity-building, enterprise development, green economy including circular economy and recycling learnerships, skills development and job placement.

April 2022 floods: learnings

The rationale for the TRMP was reinforced by the devastating April 2022 floods within eThekwini, with some areas receiving more than the 1-in-200-year event rainfall for a 24-hour period. The extent and duration of the rain meant that many of our medium-size rivers flooded.

Extensive damage was experienced to infrastructure at river crossings and to services adjacent to the rivers. Analysis has shown that alien vegetation and solid waste remain the main culprits in terms of blockages, which exacerbated the ensuing damages.

Significantly, there were far fewer blockages and less damage to the streams being managed under the Sihlanzimvelo initiative, which is further proof of the benefits of a riverine management programme.

Conclusion

eThekwini’s business case proves that it is cheaper to proactively manage our urban river systems than to repair the damage to our grey infrastructure after every storm. It is also evident that this challenge requires government and the private sector to work together for the common good.

There are many good riverine initiatives around our country, which can add value. Currently, for example, the C40 CFF is supporting the City of Cape Town and surrounding municipalities to develop a similar programme, while GIZ is providing funding for Mbombela on a gap analysis related to stormwater and riverine management. Further afield, and also through the C40 network, Harare and Mombasa have started similar programmes.

By sharing all these experiences and findings, we can ultimately develop a universal TRMP for South Africa and Africa that combats climate change and promotes a green economy.

This is an edited version of the paper entitled ‘A transformative riverine management program: a business case for a nature-based adaptation program to protect city infrastructure and so much more…’ presented at the 2022 IMESA Conference. The full paper can be downloaded at www.imesa.org.za.

The eThekwini TRMP Business Case reports and studies can be viewed at www.c40cff.org/ knowledge-library/resources-fromdurban

Westown has development rights of approximately 517 000 m² of bulk floor area

Credit: Westown Shongweni