INTRODUCTION AND BACKGROUND
The City of Cape Town, the proponent, wishes to develop a wetland park to be titled the Asanda Village Wetland Park on Erf 29865 and Erf 32680, Strand, herein referred to as “the site”. The site is bound to the north by the N2 highway, to the west by the ASLA Office Park, and the east by a pedestrian route and grounds of the Christmas Tinto Primary School. An Eskom servitude crosses the site in an east to west direction. The south and southwestern portions of the site are abutted by the informal settlements of Asanda Village. Please see Appendix A: Locality Map.
The Asanda Wetland (JES0980 in the City of Cape Town 2019 Biodiversity Network Layer) located on Erf 29865 and Erf 32680 is fed by stormwater from the N2 highway and the upstream catchment, specifically the Heritage Park development. Three stormwater inlets are located along the northern boundary of the site, adjacent to the N2 highway. The wetland currently acts as a natural conduit for stormwater from these inlets to the stormwater outlet located in the southwestern portion of the site.
The aim of the project is to upgrade and rehabilitate the Asanda wetland and enhance the larger precinct so that it can be accessible to the surrounding community. This will provide opportunities for the Asanda Village community and act as a catalyst for the regeneration of the area and its’ surrounds.
The development will occur on Erf 29865 and Erf 32680 and will affect the Asanda wetland which extends across both erven. The proposed development consists of a variety of amenities as well as some stormwater management interventions. Please see Appendix B1: Site Conceptual Plan.
The development of the Asanda Village Wetland Park will entail the following:
- A raised pedestrian crossing to facilitate safe and dry crossing in a northwest/southeast direction. This walkway will be 2.5 m in width, extending and approximately 82 m in length. The walkway will be constructed of multiple precast portal culverts, placed side to side and will be parallel to the flow direction of the wetland. Streetlamps will be placed along the mid-line of the pathway to prevent vehicles from accessing the pathways
- A multi-purpose court is proposed on the eastern boundary of the wetland. The multi-purpose court will be lined with astroturf or laterite and will have seating walls and/or E1 Concrete Edging. The Multi-purpose court is a feature of Alternative 1 and not Alternative 2.
- An amphitheatre and play area is proposed along the southwestern portion of the site.
- A community vegetable garden that is already in existence will remain as part of the proposal.
- A pedestrian pathway surfaced with laterite and lined with trees is proposed along the eastern edge of the wetland. The pathway will be a link from the bridge at the N2 highway and will be lit with streetlights to community recreational area in the southeast.
- Bollards will be placed at all existing points of the park accessible by road to allow access by maintenance vehicles while preventing access for dumping.
Part of the proposal entails stormwater management interventions which will include the following:
- The construction of a concrete sediment trap will be 500 mm deep downstream of the N2 highway at the outlet from the eastern culvert.
- The excavation of a 67 m long stormwater channel through the eastern part of the channel from the N2 highway in a north-south direction.
- Amorflex will be used to line the base and lower side slopes of the excavated channel with the base of the channel being 680 mm wide.
- Gentle shallowing of the channel to the point where it coincides with natural ground level, and flows can be dissipated into the surrounding wetland, using flanged armorflex to spread flows at the downstream end of the lined channel.
- A gabion weir (2 m wide comprising four 0.5 m gabion baskets variously set at various levels from Natural Ground Level to 250 mm above Natural Ground Level) will be constructed across the larger width of the wetland to spread stormwater flows from the aforementioned channel across the wetland. The weir will serve the purposes of preventing drought in some areas and prevent the creation of erosion gulleys/channels through other areas.
- From the gabion weir, flows would be dissipated through the existing wetland, and would presumably flow along existing low points in the wetland, passing through the pedestrian pathway culverts and being routed to the southern and southwestern portions of the wetland.
- The capacity of the existing seasonal pool in the southeastern corner of the wetland would be increased to allow for up to 24-hour retention of the 1:50 year flood – this would be enabled by:
- Repair of the outlet system from the wetland, by demolishing and removing the existing headwall; clearing out waste from the outlet; and construction of a sediment/litter trap above the inlet structure, using concrete instead of the previous gabion walls.
- Construction of a 0.5 m high berm around the southern and eastern sides of the seasonal pool. The berm will be shaped to a 1:3 slope and covered with biojute.
The EIA Regulations require that reasonable alternatives to the activity be identified and assessed. In this Basic Assessment Report, two layout alternatives have been formulated in addition to the No-Go Alternative (Alternative 3). A description of each alternative is provided below with the main difference between the alternatives being that Alternative 2 will not have a multi-purpose court and light reducing technology in the streetlamps along the walkways.
In Alternative 1, the lighting along the raised walkway/bridge has been designed to decrease illumination levels within the wetland area. The type of lighting and the placement will be in a manner that reduces any potential light pollution. For example, where illumination is necessary, concealed lights will be used where possible. At access points such as entrance points, low-level light will be implemented. These will be fitted with reflectors to avoid light spillage onto the wetland and glare will be reduced by using appropriate technology.
Included in this alternative will be the formalisation of an existing multi-purpose court. The multi-purpose court will be developed on the eastern edge of the wetland but does encroach on approximately 438 m2 of the wetland. The multi-purpose court will be lined with astroturf or laterite and edged with seating walls and/or E1 Concrete Edging. The multi-purpose court is a necessary community feature as it will encourage the use of the wetland park by the local community while also adding to the recreational value of the park.
In Alternative 2, a multi-purpose court will not be constructed as it does encroach onto the wetland. Light reducing technology in the streetlights along the walkways will also not form part of the proposal in Alternative 2 resulting in an increase in light pollution on the wetland.
The 2014 NEMA Environmental Impact Assessment Regulations of 2014, as amended, apply to the proposed development and necessitate a Basic Assessment Process. The proposed development includes activities listed in GN983 and GN985 of the 2014 EIA Regulations, as amended. These are:
Listing Notice 1 (GN983 of 2014, as amended)
The infilling or depositing of any material of more than 10 cubic metres into, or the dredging, excavation, removal or moving of soil, sand, shells, shell grit, pebbles or rock of more than 10 cubic metres from a watercourse.
Listing Notice 3 (GN984 of 2014, as amended)
The clearance of an area of 300 m2 or more of indigenous vegetation except where such clearance of indigenous vegetation is required for maintenance purposes undertaken in accordance with a maintenance management plan. In Western Cape:
iv) on land, where, at the time of the coming into effect of this Notice or thereafter such land was zoned open space, conservation, or had equivalent zoning.
DESIGN, PLANNING AND CONSTRUCTION PHASE
- Loss of Wetland Habitat
- Wetland Fragmentation
- Wetland Degradation
- Impacts on indigenous vegetation
- Impact of lighting on the raised pedestrian walkway crossing the wetland and walkway to be constructed east of the site, leading to the N2 highway.
- Visual Impact
- Increase in social and ecological amenities in the Asanda Village vicinity
- Improvement in the pedestrian routes to the N2 highway and within Asanda Village
- Wetland degradation as a result of the uncontrolled passage of vehicles and/or workers into the and contamination as a result of the passage of hydrocarbons into the wetland (e.g. as a result of machinery leakages, refuelling or breakdowns).
- Wetland degradation as a result of laydown areas and temporary stockpiling of construction materials or spoil in wetland areas
- Wetland degradation as a result of runoff of sediment from construction stockpiles into wetland areas
- Wetland degradation as a result of increased littering (especially within the core of the wetland) as a result of increased human passage into it during construction
- Wetland degradation as a result of localised erosion as a result of concentrated runoff streams (e.g. as a result of dewatering)
- Wetland degradation as a result of permanent infill creation of nodes of a disturbance where excavated spoil (eg from the channel or leftover construction material is left in the wetland).
- Wetland degradation as a result of contamination of wetland soils and water as a result of the passage of cementitious water and or sediment into the wetland (e.g. during surfacing of the raised pedestrian walkway, pedestrian pathways or surfaced play / recreational areas)
- Impact of construction activity on indigenous vegetation
- Waste Management Impacts
- Noise impact
- Dust Impacts
- Vibration Impacts
- Visual Impacts
- Employment opportunities in the construction phase
OPERATIONAL PHASE IMPACTS
- Changes in the wetland hydroperiod leading to change in wetland type
- On-gong wetland degradation
- Vandalism of structures during the operational phase
- Potential land invasions as a result of improved structures on the site
- Safety on the site
- Encroachment of informal structures on the site
- Fire during the operational phase
*Please see below for the compressed Appendices: