Popular lake under threat
Horizons chairman and council staff again disagree on how to improve water quality
Dudding Lake could “flip” into a state dominated by potentially toxic algae within two months to two years, Horizons Regional Council natural resources manager Dr Jon Roygard says.
Its closures are getting more frequent and urgent action is needed as the holiday season approaches.
The popular camping and picnic area between Bulls and Turakina has a warning sign up because its blue/ green algae level is more than twice that recommended for swimming.
Children taking a dip there three weeks ago suffered a stinging allergic rash that lasted two days.
However, at last week’s Horizons meeting in Palmerston North, chairman Bruce Gordon again said he wanted his council’s own scientists to keep out of the issue.
Gordon is also the operations manager for Dudding Lake motor camp and picnic park, and earlier this month he blasted his own council staff for putting up swimming warning signs at the lake, saying it was keeping customers away. He wants Rangitīkei District Council to deal with the problem by introducing freshwater mussels to filter the water and non-breeding carp to eat the weed.
Regarding the Rangitikei council’s efforts, he told Roygard at last week’s meeting: “I’m pleading with you . . . I really beg Jon to talk to these people doing the work.”
He said the lake has had higher algae levels than this in previous years, and always recovered.
However, Roygard backed the council team to be the best freshwater scientists, and said introducing carp would have other bad effects.
He said possible solutions included clearing the algae from the lake surface to allow light to reach the weeds growing in the depths. A chemical could also be added, to tie up the phosphate feeding algal growth.
Roygard said those standards had to be used. Horizons chief executive Michael McCartney said the two councils would talk about the lake.
Algae levels at Lake Wiritoa also jumped to twice the level recommended for swimming this week.