Nature-Based Solutions for Water Management in the Peri-Urban

Photo Stories

Invasive alien tree clearing as a Nature-based Solution: The case of the Wildlands Trust, Dwars River, South Africa

Authors: Alanna Rebelo and Karen Esler

The Nature-based Solution (NBS) implemented by Wildlands Trust in the Dwars River riparian zone involves three approaches: (1) the clearing of invasive alien trees, shrubs and weeds from the riparian zone (initially through logging operations, with follow-up clearing), (2) active rehabilitation of the riparian zone, through the planting of indigenous tree seedlings, and (3) engaging the community through creating employment opportunities in the rehabilitation programme, as well as a recycling and native tree growing programme, aimed to keep the river clean, in exchange for rewards (e.g. bicycles). This project takes a social-ecological systems approach to restoration of a modified ecosystem to make services available to society, making it a key type of NBS.

This NBS specifically tackles the issue of water quantity, by trying to make more water available in the system through clearing water-guzzling invasive alien trees. In making more water available, it also addresses the secondary but equally important challenge of water quality, through dilution effects (making more water available to dilute contaminants). The scale of this implementation is still quite small, so benefits are expected to be local. Many community members perceive improvements to nature (improvements in ecosystem services), which are experienced directly in terms of recreational benefits, improvements to aesthetics, and general well-being, social cohesion and nature-connectedness. Any benefits in terms of augmented water supply or quality, though perhaps small due to the scale of the work, would be beneficial to downstream farmers who rely on the Dwars and/or downstream Berg River for irrigation. The aim of this photo story is to highlight the value of invasive alien tree clearing as a NBS through a series of photos, demonstrating both the implementation, but also the benefits to society. The title photo shows a drone image of the Dwars River valley, in the Western Cape of South Africa, showing the rugged Boland Mountains in the background, and the arable valley in the foreground, supporting small towns, industry and agriculture (Photo credit: Cape Winelands Biosphere Reserve).


The native vegetation of the Banhoek River Valley is fynbos, and the watershed of the catchment - the high Boland Mountains - are seen in the background.
Alien trees have invaded this catchment (a sparse scattering seen here in the foreground) (Photo credit: Cape Winelands Biosphere Reserve)

The Dwars River Valley is a small subsidiary catchment of the greater Berg River Catchment, one of the most economically important rivers for the Western Cape of South Africa. This small catchment has its origin in the Boland Mountains, which receive some of the highest rainfall of the country (~1600-3000mm/a). The climate of the region is Mediterranean. The native vegetation is fire-prone fynbos, a biodiverse shrubland lacking a tree component, with the exception of the riparian zones along the river, which would have been forested. The catchment has become invaded by invasive alien trees, along the river as well as in the rest of the catchment, negatively impacting water supplies, agricultural productivity and biodiversity, and increasing fire-risk.

The social-ecological context of the Dwars River Valley - wealthy landowners of farms intersperse the low-income towns of Pniel and Lanquedoc
in the Dwars River Valley, with stark inequalities compared to adjacent landowners

With its roots in the colonisation of the Cape, the Dwars River Valley and has ties to slavery and oppression. As a result, the current socio-economic context is highly complex, with large inequalities between wealthy landowners (in some cases lucrative agriculture and luxury properties) and people residing in the local towns. The communities are affected by high crime levels and drug abuse. The valley may be classified as peri-urban given the fast paced, and highly contested, spatial transformation currently taking place. In terms of population in the local towns, in 2011 there were around 1 975 people living in Pniel, 4 328 in Kylemore, and 4 289 in Lanquedoc. Much of the working population in the small towns are employed in seasonal labour, working on surrounding farms. The local government of the valley is rather weak and fragmented, and national government provides funds for this Nature-based Solution, but otherwise provides little support. This leaves implementation of this project up to local stakeholders, with championing of this work being key to success.


First step: clearing of invasive tree species - photo is from lower down in the Berg Catchment (Photo credit: Landcare)

Second step: the riparian zone is cleared of the debris by teams of 10-12 people with a site manager. Some people use chainsaws, while others clear the vegetation by hand, removing it from the riparian zone. This photo is from lower down in the Berg Catchment (Photo credit: Landcare)

Third step: teams do revegetation of indigenous species that would not be able to return by spontaneous recovery. Here a team is doing rehabilitation planting in the riparian zone of the Berg River (Photo credit: Landcare) (Photo credit: Landcare).

The social-ecological restoration involves three approaches and takes place either on municipal or privately owned land. Firstly, the clearing of invasive alien trees, shrubs and weeds from the riparian zone. The trees are cleared initially through logging operations, using heavy machinery. This part of the implementation is done by contractors. Care is taken to minimize damage to the riparian zone, but it is a high impact intervention. Subsequent follow-up clearing may involve foliar spray of herbicides, cutting and spraying of herbicides or hand-pulling, depending on the target invasive alien species. Secondly, there is active rehabilitation of the riparian zone, through the planting of indigenous tree seedlings. Thirdly, there is an attempt to engage the community through creating employment opportunities in the rehabilitation programme, as well as a recycling programme, aimed at keeping the river clean, and Treepreneurs Project. The Treepreneurs Project encourages and empowers school learners to grow trees and sell the seedlings to the project seven to eight months later for a reward (e.g. a bicycle).


An alien clearing team working clearing invasive alien trees in the Dwars River Catchment (Photo credit: Lydia van Rooyen)

In terms of the actors involved in implementing this particular Nature-based Solution, the alien clearing work is coordinated by non-governmental organizations, in this case the Wildlands Trust, and falls under the banner of the South African national ‘Working for Water’ programme. There is some regional government interest in the rehabilitation work along the Dwars River, primarily that of the Department of Environmental and Development Planning (Western Cape Government). In terms of local governance, the Stellenbosch Municipality is involved, mainly through their role in wastewater treatment and maintenance of local parks close to the river. National government provides the bulk of the funding. There is some cross-pollination between tiers of government, for example the Department of Environment Affairs, Forestry and Fisheries (national government) specify catchment-based units of importance, and interventions are to be based on these specifications. However institutional fragmentation remains a major issue. National funding is in tandem with provincial planning, especially in the Natural Resource Management Programme; previously Working for Water, and all its affiliate groupings Working for Wetlands, Forests, etc.


Potentially illegal offtake from a weir on the Dwars River. Alien trees obscure such illegal activities in the Dwars River. Alien trees remain in the river in the foreground (alien Oaks) and the watershed in the background (Photo credit: Alanna Rebelo)

Challenges faced in the process of implementation according to implementers were: institutional fragmentation, insufficient and unreliable funding, the absence of a platform to engage landowners, tension between implementers and community, or implementers and workers, unwilling landowners or stakeholders and illegal activities. Illegal actives hampered the process of implementation because alien trees often obscure crime (e.g. illegal water abstraction from the river) and this makes complicit stakeholders unwilling to participate in, or support, alien tree clearing. The importance of a champion to drive implementation has been noted, as well as the need for better and timely community engagement and communication, particular upfront. Secondary invasion and re-invasion is also an issue after alien tree clearing, if revegetation or active restoration does not take place.


A female team member clears alien vegetation from the riparian zone of the Dwars River, South Africa (Photo credit: Lydia van Rooyen)

The Working for Water programme in South Africa is funded by national treasury, and aims to create jobs, particularly for unskilled workers. It has very strict targets for this employment, including that a certain percentage should be female (60%), youth (20%) and disabled people (5%). The benefits of supporting women in finding employment are that there are more direct impacts on family security, for example the number of children being enrolled in schools. This has, however, also been shown to be impacted by the security of this employment, which is often tenuous in these programmes.


Before (left) and after (right) alien tree clearing, showing the riparian habitat becoming more open along the Dwars River near Kylemore, South Africa, with increased visibility and recreational opportunities. It will take time before the native vegetation recovers and for the site to become more aesthetically pleasing (Photo credit: Lydia van Rooyen)

In terms of social impact, surveys among community members and workers involved in the Nature-based Solution revealed that people felt that: their connection to nature improved, that their cultural values and practices were changed, that their health and wellbeing improved, they experienced improved social cohesion and they reported reduced crime. In terms of environmental benefits, the community perceived increases in the following ecosystem services: water provision, materials and energy provision, water purification, water regulation, soil quality maintenance, life cycle maintenance, and recreation, ornamental, aesthetic and heritage services. Lastly, in terms of economic benefits, job creation and income improvements were cited by community members and implementers, and lower fire risk to landowners was highlighted.

Many lessons have been learnt through implementation of alien tree clearing as a Nature-based Solution in the Dwars River Valley context, and challenges and opportunities alike were identified. Challenges listed were: institutional fragmentation (especially within government), sustainable and sufficient funding (also earmarked funding for stakeholder engagement), long-term recovery versus society’s desire for rapid change, implementing within the context of socially vulnerable communities, and where the value of the river not recognized by the community. Despite these challenges, several opportunities were also identified. Multi-level collaboration and engagement in terms of relationship with landowners, stakeholders, implementers and government was identified as a potential opportunity, as well as the chance to investigate and build a more flexible funding model for alien tree clearing (exploring options within the private sector), and the opportunity to couple alien clearing (rehabilitation) with active restoration at scale. This is likely to result in far greater returns on investment, due to native vegetation reestablishing and keeping secondary invasion and reinvasion by alien trees at bay.