Looks can be deceiving – this is certainly the case for the Pale Yellow Water Lily (Nymphaea sp).  An introduced species, which is characterised by its heavy green foliage and pale yellow flowers, causes problems by blocking waterways and impacting on irrigation and recreational use.

Infestations of the Pale Yellow Water Lily have increased over the past few years in the Gunbower Creek according to the North Central Catchment Management Authority’s, Mr Trent Gibson.

“Despite being present in Gunbower Creek for the past 20 years, we have noticed increasing infestations.  Once established, this invasive weed can be difficult to control.  We suspect the increased nutrient levels, water temperatures and low irrigation draw down due to drought impacts are contributing factors to the proliferation of the Pale Yellow Water Lily.”

The North Central CMA in partnership with Goulburn-Murray Water is currently undertaking works to control the Pale Yellow Water Lily on the.

Mr Gibson said trials will be undertaken to assess the effectiveness of various control methods and will align with the Gunbower Landcare Group who nominated the species as a weed under the Victorian Noxious Weeds Review Stage 3.  

”Control methods usually include the use of aquatic approved glyphosate spraying during the active growth period of December-April.

“We intend to control the infestations, between the National channel offtake then downstream to the Cohuna Weir, by gradually treating strips along the centre of the waterways first and pushing outwards towards the shoreline.  Following herbicide application the decaying plant matter will be carefully monitored by installing dissolved oxygen probes to reduce the risk of a blackwater event.”

Adequate control may require several years of repeated treatments, with significant monitoring and evaluation vital to prevent the re-establishment of infestations. Funding for these works has been provided by the Australian Government through the “Enhancing the values of the Gunbower Ramsar site project”, concluded Mr Gibson.

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