Despite living at the other end of town, teenager Quinn Johnston visits regularly and enjoys feeding the ducks in the area by the lake, which Whakatāne District Council keeps away from the lilies.
Photograph: Local Democracy Reporting / provided

Residents around Lake Sullivan are bracing for another summer of foul odors from rotting vegetation and decaying wildlife.

Although Whakatāne District council has allocated a budget to clean up the lake, work to remove the Mexican water lily is not expected to begin until at least June next year.

Brian Corbett has lived on the lake for over 20 years and has been a member of the Sullivan Lake Care Group since 2013.

“Weeds have grown all over it. We have people coming to visit us and asking us ‘what happened to the lake?’ they ask. It was very attractive to visitors.

“The situation is getting worse and God knows what will happen if something is not done about it.”

He was also saddened to see the legacy of the late Sir William Sullivan, who developed the southern end of the town and created the lake, decline.

He had heard from another lakeside resident that the city would no longer spray the weeds with herbicide as people complained about the smell of dying vegetation.

He said the Mexican water lily (Nymphaea mexicana), as well as other weeds that grow along the edge of the lake, are unsightly to maintain.

He is concerned about the welfare of the lake’s bird life.

“I occasionally see white herons (kōtuku) and black swans on the lake, but nowhere near as many as before.

“The weed is spreading. The more you leave it, the worse it will get.”

The invasive Mexican Water Lily has engulfed a large portion of the lake, especially near the King Street entrance, and is spreading throughout the lake.
Photograph: Local Democracy Reporting / provided

Susan and Steven Barton have been trying to get the council to remove the invasive lily pad and silt from the lake for the last eight years. They say the weed entered the lake through the municipal stormwater system during a flood about 10 years ago.

“When I mentioned it to (open range operations manager) Ian Moloney eight years ago it was just a small patch. Now it has taken over large areas of the lake and is spreading southwards,” he said.

“At the end of King Street (the lake), especially in the summer months, there was a terrible odor emanating from rotting vegetation and dead wildlife such as fish, ducks, eels and algal blooms.”

The couple says the area is neglected because there is no toilet nearby, and people urinate in the bushes.

Sullivan Lake residents Brian Corbett and Susan and Steven Barton are concerned about the well-being of the lake environment.
Photograph: Troy Baker/LDR

Council response

Molony said the council budgeted in the draft 2024-2034 Long Range Plan to implement recommendations in environmental scientist Keith Hamill’s report, Lake Sullivan Water Quality and Enhancement Options.

Through the long-term plan negotiations process, this financing was postponed to the 2025-2026 fiscal year.

“The budgeted works will begin after July 2025 and will include mechanical removal of water lilies and organic sediment, starting at the King Street end of the lake.

“This will be followed by underlayment to prevent regrowth. Harvesting of macrophytes (aquatic plants) will also be carried out in the lake beyond the water lilies.

“Starting from July 2026, studies will be carried out to create wetlands and further harvest macrophytes.”

Weeds, trash, and dead animals like this dead duck accumulate in the weir at the western end of the lake.
Photograph: Available via LDR

He said there are no plans to spray all the lilies this year.

“Their decomposition will further worsen poor water quality and create odor problems, especially in hot weather. However, City staff will continue to maintain the visible perimeter between the shore and the lilies through spraying.”

LDR is local body journalism jointly funded by RNZ and NZ On Air.