Residential development on Portion 38 of Farm No. 136, Tergniet

Please see attached description in the "confidential" section that includes Figures and graphics.

The Applicant, Mr. Pieter de Clerk would like to apply for an environmental authorization on Farm 136, portion 38 situated in Tergniet, Western Cape. The property is located inside the urban edge and is bound by the railway line to the south and existing residential erven on the other boundaries. Robertson Avenue separates the property into two sections, the Western Site (herein after referred to as Site A) and the Eastern Site (herein after referred to as Site B).
The development proposes a total of 144 units into four types of residential developments:
• Type 1: erven size is ±175m2 and the built area is 147m2 for 75 units;
• Type 2: erven size is ±245m2 and the built area is 166m2 for 35 units;
• Type 3: erven size is ±228m2 and the built area is 190m2 for 18 units;
• Type 4: erven size is ±237m2 and the built area is 163m2 for 16 units.
The Spatial Development Plan (SDP) for Site A (western side of the property) includes 41 Type 1 units, 21 Type 2 units and 10 Type 3&4 units. Site B (eastern side of the property) includes 34 Type 1 units, 14 Type 2 units and 24 Type 3&4 units.
The property is 10.1362 Ha in total, but not all is developable, due to the Robertson Avenue that separates the property and servitudes.
Several factors were considered in designing the SDP, which included the position and connection to infrastructure, and the location of Milkwood trees, Cheesewood trees, Olive trees and Hermannia and planned the units around theses plants to try and cause the least amount of damage to established trees, to avoid clustered areas and to include open space areas.
Therefore, the total erven area covered in Site A of the site will be about 3.13Ha and about 2.83Ha in Site B.
The proposed development will transform the entire site into a residential development. Type 1 units will consist of side-by-side (horizontal duplex) units with 3 bedrooms (on the first floor and living area on the ground floor), thus double storey units with a single garage and parking bay for a second car.

Figure 1: Type 1 design
Type 2 units will be similar to Type one development with 3 bedrooms, double storey and a single garage and parking bay for a second car, but will be stand alone units.

Figure 2:Type 2 design
Type 3 units will consist of a ground, first and second floor, with a double garage on the ground floor. The units will have 3 bedrooms on the second floor and living space on the first floor and will be stand alone units.

Figure 3: Type 3 design
Type 4 units will consist of a double storey unit, with a double garage and hobby room on the ground floor and the 3 bedrooms and living area on the first floor.

Figure 4: Type 4 design




Figure 5: Proposed phase development
In terms of access to the site and according to the Traffic Impact Assessment done by Element Consulting Engineers, the access to both Sites (Site A and Site B) of the development is proposed from Robertson Avenue and the specific access point proposed is located at the point approximately halfway between the railway crossing and Steenbras Street. According to the TIA, the layout provides for an acceptably spaced intersection layout of 109m to the railway crossing and 109m to the Steenbras Street intersection with a speed limit of 60km/h on Robertson Avenue, a minor collector road.
The TIA envisaged the development of 146 medium density residential erven, which is a scenario that can be viewed as the ultimate scenario as no additional development will be possible on the site when fully developed.
The report indicated that Robertson Avenue can be classified as a municipal minor collector road and carries a very slight traffic load due to the relatively small residential area of Tergniet. The analysis concluded the following:
Intersection 1 (Robertson Avenue / Development access): the development has a negligible impact on the Level of Service during both the morning and afternoon horizon year 2030 peak hours and the intersection will continue to operate at a Level of Service A for both the morning and afternoon peak hours. No upgrades or other mitigation measures are required or proposed for the intersection.
Intersection 2: (Blesbok Street / P1578): The development has a negligible impact on the Level of Service during both the morning and afternoon horizon year 2030 peak hours and the intersection will continue to operate at a Level of Service A for both the morning and afternoon peak hours. No upgrades or other mitigation measures are required or proposed for the intersection.
The TIA further indicated the following:
• A minimum stacking distance of 3 vehicles or 15m is required at the access gate. The gate design shall provide for access for heavy vehicles and emergency vehicles. It is proposed that separate access lanes (gates) be provided for residents and visitors;
• Sight distance at the proposed access point is acceptable in both directions in both the horizontal and vertical alignments with the condition that the overgrown bush be trimmed for the complete road reserve width;
• The total horizon year 2030 traffic at the access intersection was weighed against the warrants for right turn lanes in order to consider the safety of right turn manoeuvres alongside and opposed to the main traffic stream in Impala Road. The necessity of a right turn lane is not triggered in this analysis for this intersection;
• A separate contractors’ access is not required for the relatively small scale of this development. A contractors’ access may however be considered as part of the design of the main gate complex. The main gate complex shall in any case provide for delivery vehicles in the left lane;
• Refuse removal shall be performed by the Municipality in accordance with a signed services agreement. Access for municipal refuse removal vehicles shall be incorporated into the access gate arrangements. The provision of a solid waste collection area shall be incorporated into the access gate arrangements, or in close vicinity to the access gate, in a manner so as not to hinder normal operations at the gate.

In terms of services, KLS Consulting Engineers conducted the electrical services report and Element Consulting Engineers conducted the bulk services report.
According to KLS Consulting Engineers, for the proposed new residential development, a supply of 786kVA would be required based on the development load calculations in accordance with regulations:

In terms of electrical services, the Mosselbay Municipality indicated to KLS Consulting Engineers that 1000kVA requirement is available for the proposed development.
In terms of bulk water availability, Element Consulting Engineers indicated that approximately 65kl/day for the Average Annual Daily Demand (AADD) is required for this development. A report from GLS was requested and received, confirming the availability of bulk water for the development. A letter was requested from the Mossel Bay Municipality to confirm the allocation and availability of bulk water for this development.
According to Element Consulting Engineers, the Mossel Bay Municipality has recently commenced with the phased implementation of a sewer network for the study area. A number of phases have been completed. This new municipal sewer network provides a bulk 250mm sewer line on the northern and western boundaries of this development property (Farm 136, portion 38). The Average Dry Weather Flow (ADWF) created by the proposed development is calculated at approximately 59kl/day.
In terms of the capacity in municipal pump stations, the designs of the Seester Street and Dolphin Crescent pump stations were performed to accommodate the entire masterplan study area, inclusive of this portion of development land. Sufficient capacity is hence available in the Dolphin Crescent and Seester pump stations to accommodate this development, according to Element Consulting Engineers.
In terms of the stormwater, Element Consulting Engineers indicated that stormwater design on this proposed development is notable, not only from an engineering perspective, but also from an environmental perspective, due to the moderate gradients present. A formal stormwater reticulation system will be provided by a combination of surfaced roadways, kerbs, channels, cut-off drains, inlet structures, outlet structures, concrete stormwater pipes and various minor structures. Energy dissipation will be performed as standard practice with gabion mattresses at all outlets. All pipe outlets will be standard concrete headwalls. Litter traps will be provided at all stormwater outlets and will be cleaned on a regular basis by the estate’s landscaping and maintenance teams.
The system rests on three legs, namely the minor system, the major system and the emergency system. Minor storms and normal flowoff are catered for in the normal road prism and piped system. Major storms are routed through a linked system of road prisms and public open spaces, using attenuation techniques. The emergency system recognizes failure of the minor and major systems and provides for emergency runoff by providing continuous overland flow routes to minimize flooding of residential areas.
The stormwater drainage zones were designed into Site A and Site B.
At Site A, it was estimated that 1:2 year peak flow of 0.278m3/s and 1:50 Year peak flow of 0.786m3/s. The internal stormwater network for Site A was designed to gravitate to the south-eastern boundary of the development property, which is the lowest point on Site A. The formal internal stormwater reticulation system for Site A will discharge into a proposed internal detention pond on the south-eastern corner of Site A, which will have a 351m3 capacity (the detention pond may also be split into a detention pond system – more than one smaller pond, as indicated on the SDP). The detention pond will be a focus point in the landscaping to beautify the open space areas.
Water from the detention pond will leach into the sand bed which has a very high seepage rate. The flood outlet from the internal detention pond will drain into a new stormwater culvert underneath Robertson Avenue to Site B of the development.
At Site B, it was estimated that 1:2 year peak flow of 0.321m3/s and 1:50 Year peak flow of 0.897m3/s.
The internal stormwater network for Site B was designed to gravitate to the south-eastern boundary of Site B, which is the lowest point. The formal internal stormwater reticulation system for Site B will discharge into a proposed internal detention pond on the south-eastern corner of Site B, which will have a 398m3 capacity (refer SDP). Likewise with Site A, the detention pond may also be split into a detention pond system – more than one smaller ponds, which will be the focus point in the landscaping. The outlet from the internal detention pond will drain in the existing natural drainage line towards the east along the railway line.

Figure 6: Bulk stormwater design with detention ponds (source: Element Consulting Engineers)
In terms of the environmental sensitivity, historical imagery of the site indicated that it was subjected to agricultural clearing all natural vegetation for 35 years between 1939 and 1974. By 1989 imagery indicated that agriculture was abandoned, and woody vegetation was visible, however it is not possible to know if this was predominantly indigenous or invasive woody plant species. In 2013 there seems to have been some alien vegetation clearing activity after which no further activities took place on the site to present day.
The site is surrounded by residential developments and the only open corridor remaining by 2019 was an open piece of land with one building along the western boundary of the site. According to Confluent Environmental (Pty) Ltd, who conducted the terrestrial biodiversity site verification report, even though this piece of open land still exists today, the property further west is now also being developed effectively removing the connectivity to a wider open space network and isolating Farm 38 / 136.
By 2024 (the time of completion of this report), the site had been left to recover passively (apart from the one likely alien clearing event in 2013) since at least 1989, which amounts to at least 35 years. This means that the vegetation on the site is considered natural vegetation, despite the long history of disturbance on the property (Confluent, 2024).
The vegetation type for the site according to the national vegetation map is Hartenbos Dune Thicket which is endangered. The equivalent mapped on the Vlok vegetation map for the area is ‘Hartenbos Strandveld’ and a small section along the south of the property is mapped as ‘Hartenbos Primary Dune’, which is only found in the Western Cape.

Figure 7: The National Vegetation Map of 2018 is on the left and the Vlok vegetation map is on the right with the site represented as the dotted yellow polygon (source from Confluent terrestrial biodiversity site sensitivity verification report)
According to Confluence (2024) the vegetation on the site represented a mosaic, which is how Hartenbos Dune Thicket is described. However, it seems that following the long-term prior disturbance of the site, the thicket clumps were able to recover relatively well, while the associated asteraceous fynbos matrix was unable to recover, leaving open degraded areas between more intact thicket on the site.
The majority of the indigenous vegetation on site belongs to thicket vegetation types / communities, with Milkwood trees (Sideroxylon inerme inerme) were very common on the site, and in some patches cheesewood trees (Pittorporum viridiflorum) were also common, which would require a permit to be removed, cut or disturbed from the Department of Forestry, Fisheries, and the Environment (DFFE).
The terrestrial biodiversity theme sensitivity is confirmed to be very high because the Hartenbos Dune thicket (EN) was confirmed as the vegetation type on the site, although the vegetation was greatly disturbed in the past, there has been no soil disturbance on the site for at least the past 35 years.
According to Confluence (2024), the site may seem to have a low ecological importance due to the past disturbance and numerous invasives taking over in some places, but recovering patches of thicket are doing very well without any intervention so far. Thus, in terms of the site ecological importance, the majority of the site is Medium due to the possible occurrence of SCC, the confirmed presence of Hermannia lavandulifolia and the confirmed EN vegetation type Hartenbos Dune Thicket.
In conclusion the terrestrial biodiversity site verification report completed by Confluence (2024) the terrestrial biodiversity and plant species themes are confirmed as very high and high respectively at the site. However, the vegetation on the site has not yet fully recovered since the long period of anthropogenic disturbance in the 1900s.
The site is full of invasive species, many of which have the potential to become more dominant over time. The property has also recently been isolated in an existing residential development, where all connections to wider open spaces has been significantly compromised. The SCC Hermannia lavandulifolia is not a significant population on the site, nor is it an irreplaceable species as it is common elsewhere and actually seems to thrive in disturbed areas.
For all these reasons, the site ecological importance (SEI) for the site is not high, but Medium over the majority of the site, despite the protocol sensitivities (Confluence, 2024). This is because the SEI aims to consider the specific conditions of the site, while the protocol sensitivities are more generic and do not take finer details and site context into account.
It is recommended that a specialist impact assessment be undertaken for both the botanical and terrestrial biodiversity themes on the site.
The development of the infrastructure in the area under application will be completed within 24-36 months from the date of commencement, however, the selling of individual residential units will ultimately be undertaken over the next few years in a phased manner and will be determined by market forces.