Locals are being warned to clear boats from Frankton and Roys Bay marinas or risk their boats being impounded.
Queenstown Lakes District Council harbourmaster Marty Black said the clearance was necessary to deal with the influx of people wanting to enjoy Lake Wakatipu and Lake Wanaka.
"The marinas are intended for day use only, but every year boaties take advantage of the space and leave their craft parked up long term," Mr Black said.
With annual summer growth in people and boat traffic, the marinas needed to be managed to allow access to everyone.
"All boats and trailers must be moved from both marinas, which can be used for day parking only," the harbourmaster said.
There was little choice but to apply the Reserves Act to those boats and trailers left in the marinas - meaning boats would be impounded, at the owners expense, from today.
Mr Black said he would be "more than happy" to discuss the matter with boat owners who were welcome to get in touch.
