After consultation with Otago Regional Council and regular users, localised and self-policed rules were adopted which declared only three motor-boats could go above five knots on the lake at any time, and only in an anti-clockwise direction after 3pm.
It meant that the popular holiday spot, which has a Department of Conservation camping ground nearby, could be used for swimming, paddling, kayaking, and other water sports during the day.
One St Bathans resident, who did not wish to be named, said the rules are widely posted around the area, but boaties "don't take any notice".
There were more than three boats on the water yesterday, she said.
"There were kids and families having a great time down there. They had kayaks, canoes, little inflatable boats and everything else... it was very sad," she said.
"It's too small a lake, I hope they ban boats altogether. I'm too devastated."
Many people have reacted to the tragedy by also calling for a total boating ban on the lake.
"It was only a matter of time, it is by no means a lake for boating. Very sad," Layton Craig wrote on the Otago Daily Times' Facebook page.
"A dingy or two on the lake for a fish is all its really any good for."
Anette Becher claimed there was up to four boats on the lake at the same time yesterday, including "a jet boat that recklessly went right across the edges where people were swimming".
Otago Regional Council member Graeme Bell is "astounded" that powerboats or jet-skis are allowed on the small lake.
"Dare I say it, it takes a tragedy like this sometimes to review the situation."
St Bathans woman Lorraine Bennett said there have been long-held safety concerns.
"[Our concerns] got the rules changed, it's made it a bit safer but not totally safe, not enough because this has happened."
Otago Regional Council harbourmaster Jeff Donaldson said the compromise on the lake's use had worked well, until now.
"If it has to be reviewed at the end of the investigation, then so be it," he said.
A Maritime New Zealand spokesman said officers are assisting police investigations.
"We can't comment in more detail given that it's a fatal event and police are involved," he said.
"What will follow will depend on the outcome of the investigations."
The two boats involved have been detained and the scene cordoned off.
Police reminded boat users to "take all necessary safety precautions before and on the water this summer".
The death has been referred to the coroner.
The fatal accident has been the talk of the Maniototo Rodeo today, Central Otago district deputy mayor Neil Gillespie said.
"The people involved are locals and our hearts go out to everybody. The Maniototo community look after their own and they will rally around everybody and do what they can for each other."
