New approach to weed control at Dartmouth Dam

Monday 24 April, 2017

Aerial weed control has been trialled at Dartmouth Dam for the first time.

The dam consists of an earth and rock-fill embankment on the Mitta Mitta River, located in a steep valley. 

Control of weeds on the upper spillway cut (the terraced area adjacent to the dam) and cascades is an ongoing maintenance activity for Goulburn-Murray Water (GMW) staff – and until now, has been carried out by hand.

Aquatic Plant Support Advisor Mark Finlay said annual and perennial weeds can include saplings, dogwood, blackberry and English broom.

“These must be treated to keep them in check. This work is essential maintenance so that growth of weeds does not loosen the rock faces and cause slips.

“Typically, it takes a land-based ground crew about two weeks to hand-spray the vegetation in these areas, which can be time consuming and is often a battle against the elements,” he said.

But now a helicopter has been used as a new weed control method.

A Mansfield-based aerial weed control contractor was appointed in March which resulted in 28 hectares of land treated in less than two hours.

“This is a large saving on staff resources,” Mr Finlay said.

The aerial trial was organised in conjunction with Dartmouth Storage Manager Peter Dower, who agreed there must be efficient alternatives to hand-spraying in particular areas.

“We had some discussions with aerial weed control contractors and a plan was formulated to carry out this work,” he said.

Helicopter exclusion zones were also mapped so as not to disturb resident Peregrine Falcons in the area.