A much-loved natural gem, the Lower Silvermine Wetland is a rehabilitated urban floodplain between Clovelly and Fish Hoek.
A circular walkway with a footbridge at each end and a stepping stone crossing in the middle provides access to the wetlands for people looking to enjoy Cape Town’s wild outdoor spaces. In spring, it becomes a riot of floral colour.
The dominant habitats of Hangklip Sand Fynbos and wetland vegetation support a variety of birds and animals including otter, mongoose, porcupine, duiker and the Endangered Western Leopard Toad.
In 2000, the lower Silvermine River was rehabilitated to become a wetland, having previously been an alien-infested sand canal.
A series of wetlands with open water areas were excavated with interconnected stormwater detention ponds. They were then revegetated with locally indigenous plants including coastal shrubs, flowering annuals and bulbs.
The lower Silvermine River historically had a wide floodplain and regularly flooded the lower-lying areas of Fish Hoek. Rubble and sheet metal dykes from the wreck of the Kakapo were initially used to contain the channel and ‘control’ flooding.
After severe flooding in 1991, the authorities considered formal canalisation of the river to reduce the flood risk.
However, a group of nature conservationists led by the Silvermine River Society, now the Friends of the Silvermine Nature Area (FOSNA), successfully lobbied for a wetland with connected detention ponds.
Commissioned by the City of Cape Town, this innovative wetland development won a civil engineering award. It has now been proclaimed a Wetland Biodiversity Conservation site.
The upper Silvermine River remains in a largely intact state within the Table Mountain National Park, which together with the lower wetlands forms a relatively undisturbed riverine corridor from its source to the sea in False Bay.
This level of ecological intactness is relatively unusual in urban river catchments. The annual Source to Sea hike celebrates the experience of being able to walk the entire length of the river system while learning about its biodiversity.
The nature-based recreational and educational potential of the Lower Silvermine Wetland has inspired residents to actively support the City of Cape Town’s management of the wetlands.
Managed by FOSNA, volunteers pay two Wetland Wardens to maintain paths and clear litter. Signage encourages awareness about the local plants and animals, while mosaics and an insect inn add an attractive eco-art dimension.
An extensive plant list including photographic records has been compiled and a locally extinct vygie species has been rediscovered in the wetlands.
The wetland ponds are an important breeding site for the Endangered western leopard toad (Amietophrynus pantherinus), arum lily frog (Hyperolius horstockii), Cape river frog (Amietia fuscigula) and the clicking stream frog (Strongylopus grayii).
The Lower Silvermine Wetland was the original type site for the Cape platanna (Xenopus gilli). However, it has since been recorded as locally extinct.
Around 50 bird species have been recorded here, although many of the waders have since disappeared due to the invasion of bulrush (Typha sp.).
Challenges
The Lower Silvermine Wetland is not immune to the impacts of surrounding urban development and FOSNA actively opposes inappropriate built development bordering the wetland.
Polluted stormwater runoff and periodic sewage spills temporarily impact the water quality. The growth of bulrush absorbs excess nutrients and helps to clean the water.
However, the bulrush reed beds have expanded rapidly in response to the high level of nutrients from pollution. This has reduced the area of open water and the bulrush outcompetes other plant species along the wetland margins.
FOSNA works in close collaboration with the City of Cape Town environmental staff with a collective commitment to maintaining the Lower Silvermine Wetland as an accessible and biodiverse wilderness experience at the heart of Cape Town’s Deep South.
ADDRESS: Clovelly Road, Clovelly
OPENING HOURS: 24 hours
ENTRANCE FEE: None
PUBLIC TRANSPORT: Train or taxi. A 15-minute walk from Fish Hoek Station, or free parking just off Clovelly Road at the traffic lights on Main Road
ACTIVITIES AND FACILITIES: Walking, running, birdwatching, cycling
ENVIRONMENTAL EDUCATION: Educational posters and signage
FRIENDS GROUP: Friends of Silvermine Nature Area (FOSNA) – riverroversfosna@gmail.com
CONTACT: City Parks Tel 021 701 1233
Source: FOSNA
