Waikato Regional Council is checking out several reports that came in yesterday from the public of areas containing algal blooms in the Arapuni, Karapiro and Maraetai hydro lakes during the hot summer conditions.
Water samples are being taken and results are expected within several days.
A couple of the reports have suggested that water in Arapuni and Karapiro has appeared reddish, while council staff have confirmed red colouring of water at Maraetai.
Last summer, a red appearance in water at Lake Waikare in the Lower Waikato River catchment was associated with a bloom of the algae Monoraphidium, which isn’t known to produce harmful toxins.
Sampling last month in the hydro lakes indicated low levels of Monoraphidium, although the type was differentfrom that seen at Lake Waikare last year.
Last month’s sampling also indicated Monoraphidium in Lake Waikare was on the rise again.
Water, air and waste manager Dominique Noiton said it was too early to tell exactly what was happening in the hydro lakes where the fresh bloom reports have come from.
“We’ll be assessing the sampling results when they’re through to see what might be causing these reported blooms and we’ll liaise as necessary with the district health board over any relevant advice to the public.
“Blooms of algae can be common at this time of year during warmer weather but we haven’t had any confirmed reports of toxic blue-green algal blooms on the Waikato River system since Lake Ohakuri four years ago.”