Community rallies to fight hyacinth in the Bronkhorstspruit Dam

Caring community members helped to remove hyacinth from the Bronkhorstspruit Dam on Sunday, March 20.

They gathered at the Bronkies Angling and Nature Reserve to assist in any way they could.

Once the hyacinth was pulled from the water, it was moved to a trench on the reserve where it is dried out to be used to make commodities such as weaved baskets for resale to the very same community that assisted in removing the hyacinth.

The dam is eutrophic with blue-green algae and has been a problem since 2017 due to wastewater treatment works and other illegal discharges.

This pollution causes an excess of cyanobacteria (blue-green algae), as nutrients such as nitrates and phosphates in the water feed all types of water plants, including the hyacinth.

According to farming in SA, 1980, “The plant may reproduce vegetatively at an alarming rate through side shoots which break off and develop into new plants. Actively growing colonies can double their numbers every 11-18 days.”

According to the Bronkhorstspruit Catchment Forum, residents and the river community alerted them when hyacinth was first discovered upstream of the dam, in the Bronkies River in late Feb 2021 and then in the actual dam in late April 2021.

“It was quite a shock when we first discovered it. We contacted all the relevant departments and immediately began to plan to manage this hyacinth.

“We also appointed a hyacinth coordinator, Paddy Waller, to assist with the various aspects of the hyacinth control plan,” Cara Stokes, BCMF chairperson, said.

Fast forward to March 2022 and 100s of hyacinth plants were washed into the dam by the summer floods and are now rapidly growing and forming patches around the edges of the dam, especially on the side of the nature reserve.

The main drive of the rapidly growing hyacinth is the poor water quality that the dam has received from various upstream activities which the forum has fought against for the last 5 years.

“We as a community are fed up with the destruction of the environment, either by pure incompetence or a complete disregard of the fiduciary role of government. This should be tackled through greater community awareness and proactive and remedial action on the side of affected communities in the first instance,” said Johann Walters.

The Bronkhorstspruit Catchment Management Forum has completed the risk assessment to spray with Kilomax (sub-lethal spraying) along with the release of the water hyacinth planthopper (megamelus) as biocontrol and for a boom at the nature reserve as well as to manually remove hyacinth.

The forum awaits the final submittal and approval of this document to begin spot spraying. There is a short window to spray hyacinth each year and the forum is concerned they will miss that window this year if the authorisation is not provided in time

“We desperately need more volunteers to join in the various BCMF tasks such as polluter monitoring, river surveying and biocontrol rearing and releasing,” said Waller.

Lunch and labourers were sponsored by the Bronkies community and a festive sunny day was had by all.

Join the Bronkies Catchment Management Forum on Facebook or contact 083 651 8297 if you want to assist in any way.