Alien plants taking up most of the water in the Gobos: WWF-SA

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South Africa has critical high lying mountain catchments where the majority of the rain falls and where major rivers start.

WWF-SA’s Journey of Water 2019 focused on the Boland Water Source Area in the Western Cape; one of 22 strategic water source areas that make up 10% of our land, but provide 50% of our water.

The specific focus for 2019’s Journey of Water focus is the Riviersonderend River that supplies water to the Cape’s biggest dam, Theewaterskloof.

The Journey started in the small town of Greyton in the Overberg region and for 2019; walkers quickly became part of nature by crossing the Gobos River, a tributary of the Riviersonderend.

The Gobos is overgrown with alien invasive trees and, as a result, less water reaches the Riviersonderond river.

Rodney February, Implementation Manager of Boland Water Source partnership WWF-SA, says that invasive plants are a problem as they use more water than indigenous plants.

“All the large trees behind me are mostly alien invasive plants; there are a number of species behind me, but they all shouldn’t be there. Invasive plants are a major problem; the biggest problem is that they use more water than our indigenous plant, but also they cause the banks to collapse which is a secondary problem with invasive. It’s not only the water use. Once the aliens have invaded the river system, they have to be removed and once removed, there is very little left in and around our rivers which affects water quality and quantity, so the river systems need to be restored.”

Director of JJ Producers, Lumka Madolo, says that there is a community nursery for growing indigenous plants.

“This is Genandendal community nursery where we propagate our indigenous plants for the alien clearing and restoration project in Riviersonderend. We employed local communities from Genandendal and Greyton, so we have 19 people that are here growing indigenous plants that we plant them our local rivers and Riviersonderend the main river. This is one of our indigenous plants called Virgilia and it helps the riverbanks; it holds the soil and stabilizes the banks and protects against erosion. It also supports the regrowth of the alien invasive plants. If we do restoration after the alien clearing, it helps to protect and suppress the regrowth of alien invasive plants.”

Partnership Manager of Boland Water Source Partnership WWF-SA, Helen Stuart, says:

“We’re standing on the Meulriver Bridge and it’s hard to believe what was behind me all you could see was just rocks in 2016. Sometimes, when you clear, it’s just there’s nothing left behind. It’s actually necessary what we call active restoration where you go and get the plants you saw grow up in the nursery and bring them and plant them in the areas that you have cleared. And this year, the plants are doing a really important function of supporting the bridge so engineers came to us they fixed the bridge after a big flood event and then we’re going. Actually, this is not enough, we need some natural infrastructure so we’re having the actual plants being put in to make it a healthier system and that’s what’s been achieved here and if you look into the river, you’ll see some really important plants like palmist that are slowing down the rivers pace as it comes through underneath.”

Once the clearing and restoration has been done in a river, continued follow-up clearing needs to take place to ensure that the alien invasive species do not take over again, spread and choke out indigenous vegetation.