There are several technical methods up for consultation, and a combination of these could be implemented. Technical methods include continued monitoring, mixing the water with compressed air, adding water from another source, withdrawing nutrient-rich water from the lake and applying the chemical alum.

These methods specifically target the historic accumulation of phosphorus in the lakebed, and other workstreams are looking to improve management of the Lake Hayes catchment.

ORC General Manager Operations Dr Gavin Palmer says a balancing act is needed to achieve a healthy lake.

“Lake Hayes is a vital cultural, environmental and economic water body for Otago, which is why public opinion and understanding of how we approach restoration is important. Each of the methods carries some advantages and drawbacks.

“It’s important that the community understands the rationale for each method and how it may affect them. We will be running drop-in sessions where a panel of both ORC and independent experts will be available to answer questions, so that any risks or drawbacks can be properly understood.”

Friends of Lake Hayes Chair Mike Hanff says he welcomes the consultation.

“It is pleasing to see the next steps being taken to restore the health of the lake, and for all groups to be moving forward together to achieve the same objective: a healthy, swimmable lake. Friends of Lake Hayes believe that by addressing the quality of water that enters the lake first and foremost, with ongoing monitoring and evaluation, we are moving towards restoring the health of Lake Hayes.

“We encourage anyone who is concerned about the health of the lake to provide feedback on these options, that may pair well with the introduction of an updated catchment management plan.”

Lake Hayes suffers from periodic algal blooms that occur due to a build-up of phosphorus in lake bed sediments, a nutrient that has built up over the last seventy years from human activity around the lake. During algal blooms, the lake becomes unsuitable for safe recreational use, and ORC hopes that with its proposed intervention methods, Lake Hayes may become suitable for swimming at all times.

The monitoring buoy deployed in Lake Hayes by ORC in July will be valuable for identifying the outcomes of restoration efforts. ORC has also contributed funding to the wetlands restoration research project being led by Friends of Lake Hayes.

Feedback will be presented to Council for their consideration to inform the next steps in restoring the health of Lake Hayes.

TALK TO THE EXPERTS

A panel of ORC and independent experts will be available to discuss these restoration methods at Lake Hayes Pavilion on the following dates and times:

Tuesday 13 August 2019

12:00pm to 1:30pm, and

5.30pm to 7:00pm

and

Tuesday 3 September 2019

12:00pm to 1:30pm, and

5.30pm to 7:00pm

HAVE YOUR SAY

Feedback is open at the ORC YourSay Lake Hayes webpage from 6 August until 3 September.

For more information and to provide your feedback, please visit: https://yoursay.orc.govt.nz/lakehayes