Introduction:
Kenridge, like so many of the suburban areas in Durbanville, was once farmland. The Kenridge Park was one of the few places that has survived as public open space as it is a natural watershed and becomes water-logged in the winters.
The duck pond itself is an old farm dam that is fed by springs. You can see where the water comes up along the edge of the dam if you look carefully between the “island” and the large Rhus (or Searsia) on the uphill side at the end of Mildred Road.
The duck pond is in fact classified as part of the municipal storm-water system and is known as a retention dam. The water level in the duck pond is controlled by a weir on the lower side.
Water flowing over the weir runs down a channel to another retention dam opposite the shopping centre. This acts as a break on the velocity of the water, which then flows out of the lower retention dam via a concrete channel into a storm-water pipe that takes it underground and into Doordekraal Dam.
Over the years the Duck Pond has developed its own ecology. We have seen freshwater crabs, and signs that Cape clawless otters have been feeding on them. There are terrapins (freshwater turtles) in the dam who tend to be aggressive. There are also some sizeable fish including Tilapia, Barbel and a few Koi presumably dumped there by residents.
In summer the dam attracts dragonflies and the clicking of frogs can be heard. Birdlife includes African Spoonbill, Grey and Black-necked Heron, Yellow-billed Duck, Moorhens, Bishops, Cape Weavers and Roosting Swallows with occasional Malachite Kingfisher. Feral ducks (Quakkers) and Egyptian Geese are common. Hadeda and Sacred Ibis feed in the surrounding grassland and Blacksmith Plovers breed near the lower dam.
Vision & Current Phase:
We as the Kenridge The Hills Rate Payers Association would like our cherished Duck Pond to become a center of pride for the Greater Kenridge. Our vision is to cut down the overgrown Typha, and keep it under control so that it doesn’t become overgrown.
We plan on achieving effective control by hand cutting at the end of the growing season and when water levels are low, two clippings about a week or two apart will achieve the best results. Once the cut area is done it will need to be submerged in water of at least 8 to 10 cm.
We also would like to create a healthier ecosystem around the dam; we will have to plant other indigenous water plants to replace the Typha. The system has to be managed, indigenous plants also have the ability to become invasive and take over. It is vitally important that the dam level remains stable.
Hambisela Horticultural Services has been recruited to take on this monstrous task. Phase one is to remove and control the Typha, expand the footprint of the top dam, trim trees and general upgrade the area. Hambisela Horticultural Services will also be maintaining the Duckpond on a weekly basis once phase one is complete.
To track the progress of the duck pond upgrade, please join the official Greater Kenridge Facebook group at https://www.facebook.com/groups/greaterkenridge
Sponsor of the project:
The Rose Cottage is an AirBNB business based in the leafy suburb of Kenridge. The Rose Cottage Team is passionate about our community and enjoys participating in community projects that uplift the area and creates an enjoyable environment for our community.
For more information about The Rose Cottage, visit www.therosecottage.co.za or follow them on Facebook or Instagram
Photo cred: “Hambisela Horticultural Services”
Controlling Typha
Hambisela Horticultural Services has provided an in-depth view of controlling Typha and explains the process of managing it at the duck pond:
Typha capensis is a rhizome, also called creeping rootstalk, with horizontal underground plant stems capable of producing the shoot and root systems of a new plant. In addition, those modified stems allow the parent plant to propagate vegetatively – {asexually}, and some plants, such as poplars and various bamboos, rely heavily on rhizomes for that purpose.
Put simply, every time a piece of the rhizome is broken or disturbed a new plant forms, making it very difficult to remove by digging them out by hand or by any other mechanical means. Even using a more aggressive method of removal for example a digger loader, damage to the pond ecosystem is not a viable option.
Controlling excessive Typha growth is extremely difficult, particularly in natural systems.
Various methods have been tried and tested all over the world, but there is no easy way to control the plant. Herbicides can be effective when applied while the plant is flowering, but the disadvantage is that the decaying plant material accumulates and results in hypertrophic conditions, this plant material also provides a good substrate for the regrowth of Typha.
Some herbicides also have a negative effect on the water quality and animal life in the system. Mechanical removal is also made difficult because of the depth and volume of the rhizomes.
The continual removal of new growth and young seedlings helps to reduce the infestation.
The best way to effectively control Typha capensis is by using fire and physical cutting in conjunction with flooding. If the reeds are burnt and/or cut when the water levels are low, and then flooded, growth is considerably inhibited BUT NOT STOPPED.
To be very clear, Typha capensis needs to be managed, it gets out of control when the water systems are not being managed properly and the water level continually fluctuates.
An effective control can be achieved by a combination of mechanical and hand cutting at the end of the growing season and when water levels are low, two clippings about a week or two apart will achieve the best results, but then the cut area MUST BE SUBMERGED IN WATER SOON AFTER in at least 8 to 10cm’s of water when water levels rise again.
And finally, to create a healthier ecosystem around the dam, other indigenous water plants need to be planted to replace the Typha, but all things being equal, the system has to be managed, indigenous plants also have the ability to become invasive and take over. Seasonal cutting back is important for the ecosystem at the right time of the year. But I cannot emphasise enough, it is VITALLY IMPORTANT THAT THE DAM LEVELS REMAIN STABLE.
