A statement from the Bremner Bay catchment group said volunteers would collect water samples from the bay to be sent to Hill Labs in Christchurch for E.coli analysis every Tuesday.
"All results will be published weekly and the group encourages all swimmers and lake users to check these updates regularly," the statement said.
The group, formed through Wai Wānaka’s urban catchment programme, launched a summer water quality monitoring project earlier this month which would continue until the middle of February.
Bremner Bay catchment group member Murray Gifford said the message was to think about what was going into drains.
"It all ends up back in the lake — a large part of this is educating people on what is safe," he said.
"Generally the E.coli count in the lake is low .For it to be swimmable, it has to be below 260 [E.coli per 100ml].
"We know that a lot of people swim here this time of year, the advice is that you don't swim [for] 48 hours after rainfall."
The group also collected samples after large rainfall.
Guardians of Lake Wānaka chairman Dr Don Robertson said lake users could expect faecal contamination following rainfall anywhere in the entire Lake Wānaka catchment.
"Whenever we have heavy rain, runoff from the Bremner Bay catchment brings contaminated surface water into the bay.
"This could include dog and other animal faeces as well as toilet contents disposed by travellers with campervans and from leaking sewers.
"Normally much of the contamination will dissipate within a few days after rain stops," he said.
Temporary signage at the bay provides QR codes for the public to access the results, supported by the Queenstown Lakes District Council parks team.
The council had a long-standing relationship with Wai Wānaka and its associated volunteer project working groups, such as the Bremner Bay catchment group, a council spokesman said.
"This is a great example of local community action helping to protect freshwater and keep people informed.
"We’ll continue to support their valuable mahi in ways such as adding educational info to existing council signage within public reserves, promoting opportunities for the public to get involved and sharing/reviewing research data to improve outcomes for the wider community."
For example, the council’s parks, property and infrastructure team completed a baseline data survey at Bremner Bay, he said.
The catchment group’s statement said they hoped by openly sharing data they could help everyone enjoy the bay safely and contribute to "long-term environmental stewardship".
"This vision was developed with facilitation from Wai Wānaka and reflects the community’s commitment to understanding, protecting and restoring this much-loved local swimming spot," it said.
