Widespread benefits from willow control works
26 June 2015
Willow control works have recently been completed along a 12 kilometre stretch of the Brogo River from Brogo Dam to Brogo Pass, with the assistance of local landholders and funding from the NSW Government's Environmental Trust.
South East Local Land Services project coordinator, Shannon Brennan said the control works were undertaken using stem injection methods to reduce blockages and bank erosion and open up the river channel.
"The upper Brogo River is in relatively good condition with healthy riparian vegetation, diverse instream habitat and evidence of a healthy fish population," Ms Brennan said.
"In recent years crack willow invasion has been a major threat to river condition."
"This willow species has been declared a Weed of National Significance. It tends to grow instream and spreads by branches detaching and re-establishing in sand. As the willows grow into larger trees an entire channel can become blocked.
"Willow choking reduces a river's ecological function. Water flows are pushed into riverbanks causing erosion and sediment build-up on the river bed. Shallow, rocky riffle areas which are important areas for fish feeding become covered in fine sand.
"Recent studies by CSIRO have shown that willows growing instream can take up more than 5 megalitres of water per hectare of willow canopy area per year," Ms Brennan said.
Willow control works started in this section of the Brogo River during 2013, to reduce chokes and open up a low flow channel. The success of the first pass lead to the commencement of the second phase of works in early 2015, to achieve total willow control along the channel width for 12 kilometres.
Ms Brennan said willow removal has achieved environmental, social and economic outcomes.
"The change in the river system has been considerable. There is clear evidence that riffle zones are opening to improve flow and passage which benefits fish feeding and breeding.
"Paddling the river is now a much safer and more enjoyable experience as kayaks no longer become tangled in choke points.
"These works have also built on the efforts of Local Land Services' Koori work crew which has been undertaking Saggitaria (an invasive aquatic weed) control along the river over the past two years."
For further information on this project, please contact Shannon Brennan, South East Local Land Services, Bega on (02) 6491 7823.
Media contact: Shannon Brennan (02 6491 7823 or 0428 259 245)