The North Central Catchment Management Authority (CMA), in partnership with Goulburn-Murray Water, is currently undertaking spraying works to retreat infestations of the Pale Yellow Water Lily (Nymphaea sp) on Gunbower Creek and nearby lagoons.   

An introduced species characterised by heavy green foliage and pale yellow flowers, Pale Yellow Water Lily causes problems by blocking waterways, impacting on irrigation and recreational use. It rapidly colonizes shallow, nutrient-rich waters, resulting in dense infestations that restrict water movement and contribute to silt build-up in the creek.   

According to local residents and Trent Gibson, North Central CMA’s project manager, infestations of the plant have increased dramatically over the past few years in the creek.   

“Several local groups, including the Gunbower Island Community Reference Group, have raised this as being of major concern of the local community,” Mr Gibson said.   “While there have been numerous treatments in the past, this year is the first of a planned five year program to significantly reduce the extent of the lily in Gunbower Creek.   

“Results of recent trials indicate the best approach to reduce infestations is to spray the lily during the early and late active growth period in November and March,” Mr Gibson said.   

Infestations between the National Channel off-take and then downstream to the Cohuna Weir will be controlled by gradually treating strips along the centre of the waterways first, then pushing outwards towards the shoreline.   Following herbicide application the decaying lily is carefully monitored by water monitoring probes to reduce the risk of a blackwater event. 

Several years of repeated treatment are required, with monitoring and evaluation vital to prevent the re-establishment of infestations.   

Funding for this year’s work is provided by the Australian Government through the Gunbower Key Asset Protection project. To find out more about the program visit www.nccma.vic.gov.au. 

For further information please contact: 

Communications Officer, North Central CMA
PO Box 18, Huntly VIC 3551

t: 03 5448 7124
e: info@nccma.vic.gov.au