The need to increase sewer pipeline capacity is a common challenge facing municipalities in South Africa, particularly in areas with rapidly growing populations. This rapid growth has led to a demand for housing, infrastructure and land resulting in an increased encroachment to municipal servitudes. This situation has become a concern in South Africa, especially in informal settlements, which are often near drainage paths or easements.
Municipal servitude encroachment is a serious issue that can have significant negative impacts on municipal pipelines, leading to damages, contamination, and poor health outcomes. When private property owners build structures or plant trees on municipal servitudes, which are designated areas where municipal infrastructure is installed, they can damage or even rupture the pipelines that carry clean water, wastewater, or stormwater. This can cause leakages that not only waste precious resources but also pose health risks to community members who rely on the municipal water supply. Furthermore, when informal communities who encroach municipal servitudes do not have access to basic infrastructure like water and sanitation facilities this exacerbates health risks and exposes the surrounding community to communicable diseases. In addition to health problems, these leakages can also cause further problems, such as sinkholes, flooding, or pollution of nearby water bodies. It’s critical for municipalities and private property owners to work together to prevent servitude encroachment, and emphasize the importance of maintaining the integrity of municipal infrastructure to protect public health and safety, and to ensure the sustainable use of resources.
Municipal servitudes are legal agreements between a municipality and a property owner that allow essential services such as water pipelines or sewerage lines to be constructed, installed, and maintained on private property. Many people living in informal settlements are unaware of these agreements, and as a result, often build homes on top of these servitudes or encroach on them with other structures.
Built environment professionals and municipalities in South Africa use several policies and by-laws to address the issue of encroachment on municipal servitudes. The National Building Regulations, for instance, require that all new buildings must be inspected to ensure that they do not encroach on or impede upon infrastructure such as pipelines or drainage easements. The Spatial Planning and Land Use Management Act (SPLUMA) of 2013 empowers municipal planners to protect municipal servitudes from development and to ensure that existing infrastructure is not encroached upon. Municipalities are also responsible for enforcing by-laws and regulations that address encroachment.
In some cases, municipalities have attempted to deal with this issue by evicting informal settlements and removing illegal structures that encroach on the pipeline’s right of way. However, these attempts at eviction are often met with resistance or protests from the affected residents. To address the issue of encroachment on municipal servitudes in South Africa, a coordinated effort between government structures, municipalities, and communities is necessary.
The City of Ekurhuleni (CoE) was faced with challenges of insufficient capacity of their sewer outfall and the encroachment of informal and formal settlements built on the pipeline. Ditlou Consulting was thus appointed by the CoE to find a solution to the conveyance, operations and maintenance challenges related to the Boksburg-Waterval Dekema Rondebult outfalls sewer through Elsburg. To remedy these issues the consultancy proposed a rerouting and increasing capacity of the 1.7km length section of the outfall sewer. The sewer outfall is a critical piece of infrastructure for the surrounding communities and industries, so finding sustainable solutions that address the insufficient capacity of the outfall together with the informal settlement issue was essential.
The problem with insufficient capacity was addressed by proposing an upgrading the outfall sewer through increasing its capacity. This was done by increasing the size of the sewer pipeline however, other means of solutions can be to include additional sewers to handle the increased flow or to reduce the amount of wastewater entering the sewer system through water conservation efforts and the use of alternative water sources such as rainwater harvesting.
The more complex problem is of the informal settlements that are already established in the corridor reserved for the pipeline. One solution is to enforce land-use regulations that prohibit the construction of settlements along the pipeline corridor. This will involve working with local authorities to enforce zoning regulations and prevent further encroachment on the pipeline corridor. Creating a buffer zone around the pipeline corridor should also be considered. Another solution which is the most effective one to this problem is to work with the local government to relocate the formal and informal settlements away from the outfall sewer pipeline and manholes. This will require collaboration with the residents of the affected settlements to find a suitable new location. Appropriate relocation options must be available before relocation is proposed. However, this would not be the most feasible solution as the existing Rondebult Outfall Sewer has reached the end of its design life and needs overall replacement.
To resolve this matter rerouting the sewer pipeline to avoid encroachment on the existing pipeline and increase its capacity was the approach taken by Ditlou Consulting. The advantage of this approach is that it avoids the obstacles that cause congestion, such as buildings or other infrastructure, and increases the capacity of the system, which helps reduce blockages, overflows, and other problems in the future. Rerouting a pipeline can also be a more environmentally friendly solution as well. By avoiding sensitive areas, such as wetlands or wildlife habitats, and by using trenchless technologies, it’s possible to minimize the impact on the environment. However, rerouting a sewer pipeline is not always a straightforward process. It requires careful planning and coordination with multiple stakeholders, such as property owners, local authorities, and utility providers. There may also be challenges related to funding, permits, and public opinion. Despite these challenges, rerouting the sewer pipeline as proposed by the consultancy was an effective and sustainable solution that addresses the problem of insufficient capacity and prevents encroachment on the environment.
It is important to work with experienced engineers and experts who can provide guidance and support throughout the process to ensure a successful outcome. The following factors were taken into consideration:
- Land availability: The availability of land to reroute the pipeline is an important factor. The new land must be suitable for the construction of a sewer pipeline and must not have any existing structures or settlements along the planned route.
- Environmental impact: The rerouting of a sewer pipeline may have an impact on the environment. An environmental impact assessment must be done to establish the impact of the rerouting and necessary mitigation measures to ensure that there are no adverse impacts on the environment.
- Cost: Rerouting a sewer pipeline can be expensive, with the cost of construction, land acquisition, and environmental assessments. As such, it cannot be done without careful planning and careful consideration of available resources.
- Collaboration with key stakeholders: Rerouting a sewer pipeline requires coordination and collaboration with key stakeholders, including local government authorities, affected communities, and other relevant parties. Sufficient consultation and community engagement are necessary for the success of the project.
While rerouting a sewer pipeline presents some challenges, it is an effective solution to address the problems encountered by the CoE. The approved sewer line for the rerouting was proposed to be constructed on two bridge type structures. The bridge type structures are designed and constructed to the lengths of 80m consisting of 8 equal spans of 10m and 60m consisting of 6 equal spans of 10m to carry a 1000mm diameter Class 4 HDPE pipe. The pipe is to cross over the Elsburgspruit stream at two different positions running downstream at a slope between 0.65% to 1.5% with velocities between 3.290m/s and 4.470m/s acceptable with the CoE standards.
The project commenced on the 19th of August 2022 with Itumeleng Mmolutsi as the resident engineer, and reached practical completion on 31 December 2022 when the bridge type structures had been completed while the pipeline is still to be installed. The pipe centerline is located between 1.5m and 2m above NGL for most of the bridge length because it is connecting to an already existing sewer pipeline.
To avoid encroachment issues over sewer pipelines in the future, municipalities need to take more proactive roles. Public education campaigns are essential in addressing the encroachment issue. By raising awareness about the risk of encroaching on sewer pipelines and other municipal servitudes, municipalities can help property owners and developers understand the importance of complying with regulations and guidelines. A comprehensive public education campaign can help to educate property owners and developers about their responsibilities when it comes to building or developing near pipelines, including obtaining the necessary permits and approvals, adhering to setback requirements, and avoiding grading or excavation activities that could damage or obstruct the pipeline. Municipalities can also work with developers to identify and avoid areas that may be at risk of encroachment to minimize the risk of encroachment occurring in the first place.
The reforestation and maintenance of a vegetative cover along the pipeline corridor can be effective in preventing encroachment. By creating a natural barrier around the pipeline, property owners and developers may be deterred from building or developing in the area. Additionally, vegetation can absorb excess water and help to stabilize the soil, reducing the risk of erosion and landslides that could damage or obstruct the pipeline. However, this type of solution can require significant resources and coordination with multiple stakeholders. Land acquisition and management, tree planting, and ongoing maintenance can be costly and time-consuming, and may require coordination with other government agencies, non-profit organizations, and community groups. It is important to recognize that implementing sustainable solutions like reforestation and maintenance of a vegetative cover requires a long-term commitment to maintenance and monitoring. Once the vegetation is established, ongoing maintenance is necessary to ensure that it continues to provide the desired level of protection. Overall, reforestation and maintenance of a vegetative cover can be a viable solution for preventing encroachment, but it is essential to carefully evaluate the costs, resources, and feasibility of this strategy before deciding to move forward.
