Bronkhorstspruit at risk of being taken over by water hyacinths

If something drastic is not done soon, the Bronkhorstspruit Dam will soon become the “other” Hartebeespoort Dam.

This is Bronkhorstspruit resident, Paddy Waller’s take on water hyacinths invading the Bronhorstspruit Dam.

“Locals need to act now and initiate projects to curb the spread,” said Waller.

Gerhard Fleischman who has been the owner of Kaia Manzi Resort in Bronkhorstspruit for the last 20 years agrees with Waller that should the water hyacinth not get sorted out, it could become a massive problem in the future.

“There are plans in place to reduce pollution going forward.

“Thus far there has luckily been no impact on my resort, but if left unattended it could cause long-term problems,” said Fleischman.

Water hyacinths are posing a problem in Bronkhorstspruit Dam where residents are getting together in the hope to curb the spread of this invasive weed that could have long-term damaging effects on aquatic ecosystems.

Other potential problems include obstruction of river flow, interference with recreational activities such as fishing and skiing, huge financial implications such as loss of property value and simply the cost of constantly removing them, as well as creating potential health risks by becoming a breeding ground for mosquitos (malaria) and other disease vectors such as the bilharzia snail.

According to Cara Stokes, chairperson of the Bronkhorstspruit Catchment Management Forum and environmental advisor, the first hyacinths on the dam were discovered in April 2021.

This was mainly due to Covid-19 as no one was allowed on the water during that period. This left the hyacinths undetected and free to flourish.

Another place it is coming from is Delmas (upstream), which never had water hyacinths until the floods of 2020.
Stokes said hyacinth has, however, been present for about 15 years downstream.

According to Stokes, a multiple integrated approach has been put into place to curb the growth and hopefully eradicate the water hyacinths.

This includes applying Biocontrol (releasing the planthopper Megamelus bug), creating four stations in the catchment area where the water hyacinths are caught before being washed into the dam and also applying for authorisation to spray the water hyacinth with sub-lethal amounts which enhance Megamelus (biocontrol) and then mechanically removing it from the water.

Currently, residents of Bronkhorstspruit are mechanically removing the water hyacinth and releasing bugs (biocontrol) while awaiting authorisation to spray them, but according to Stokes, the application is taking extremely long to a very urgent situation.

“To win this war on hyacinths, we need to win the war on the quality of water,” said Stokes.

“Water hyacinths are an indication of the poor quality of water, ” she said.

“The long-term plan is to clean the water upstream, to create artificial wetlands which will serve to improve incoming water and to crack down on polluters.

“Downstream there is also a sewage problem with the Godrich Waste Water Treatment Plant.

“The pump station overflows which leads to the Premier Mine Dam from where Cullinan gets its drinking water. There are also massive hyacinth problems, but when it floods the hyacinth is washed downstream.” Stokes explained.

“We are also trying to manage that with biocontrol and potentially sub-lethal spraying, ” she said.

Another concern is the mine discharge that spilt into the water between June and August which killed all the macroinvertebrates in the river.

Stokes and her team are currently monitoring the situation and recovery. Stokes will be meeting with the Tshwane Nature Reserve to discuss plans going forward.

“Donations have been pouring in from residents to assist with the problem,” said Stokes.

“The community is pulling together.”

Hyacinths are not allowed to be transported and have to stay on a property, but luckily locals are busy using it as compost, to feed animals and another local has taken initiative and is using it to weave baskets.

“Everyone wants to see a clean dam,” said Lana van der Kloof, also a resident of Bronkhorstspruit.

She thanked the families of Bronkhorstspruit who are taking action and cleaning up the dam on their own accord.