The anxious wait for suitable weather conditions to allow aerial spraying to begin over the Waihola-Waipori wetlands ended yesterday, one the eve of World Wetlands Day.
There was only a month-long window of opportunity to undertake a successful weed-control programme on pest plants such as willows and they were already halfway through it, Lake Waihola Waipori Wetlands Society chairman David Vollweiler said yesterday.
Windy, unsettled weather had meant spraying was not possible until yesterday morning, when two helicopters took to the air.
"We're quite relieved. I had been getting anxious.
"In another week or two, I would have had to make a decision on whether to cancel or not."
The spray contractors were using glyphosate, the only spray approved over waterways and a new product called Darlon that Doc was trialling on four 1ha blocks, he said.
Doc freshwater ranger Pete Ravenscroft said weeds threatened long-term management of the wetlands.
"These invasive plants are slowly choking the waters, affecting natural water movement and reducing water quality, as well as contributing to increased siltation."
