A 75-page report will be presented to Councillors on Wednesday, providing an information update on water quality issues at Lake Hood and the work currently underway to address them.

Chief Executive Hamish Riach said a lot of work had been done to understand the complex nature of the lake since the first algal bloom in 2023.

“From the background work we’ve done, we have not yet come across any examples of cyanobacteria having been successfully eliminated from a lake the size of Lake Hood, so at this stage we are working towards mitigating the blooms.”

Council is working with key partners to ensure the approach is scientific and feasible.

“We’re working with Lincoln University and NIWA to start PhD research and trials in the lake canals later this year.”

This work is being led by Professor Susie Wood, an internationally recognised scientific expert on cyanobacteria.

Council is also considering future options for increasing water flows into the lake, including the feasibility of applying for a short-term, non-consumptive take.

The report highlights three main themes to help tackle water quality issues: identifying options for mitigating cyanobacteria blooms using a scientific approach, improving the intake and outlet infrastructure, and consenting options to increase water flow.

The report also covers potential funding options for major works at Lake Hood in the future.

Mr Riach said the water level in the lake had been lowered over recent days to allow for winter flushing and maintenance work.

“Flushing simply means letting old water out and new water in, and maintenance can be carried out on boat ramps and banks while the lake is low.”

While the water body is closed to the public due to the public health warning, other land areas of the aquatic park remain open. People can still ride their bikes around the lake, walk, play golf and visit the restaurant.

The full lake report can be found on the Council meetings page, as part of the agenda for the 21 May Council meeting. The meeting will also be livestreamed.

Previous updates on Lake Hood can be found here.