Boat owners are being warned to take care on Lakes Benmore and Aviemore after the release of water from hydro dams.
The lakes above the dams on the Tekapo, Pukaki and Ohau rivers are full and Meridian Energy has been spilling water from them down the rivers since Wednesday.
The regional harbourmaster Tony Whiteley says the releases have washed trees into the lakes further down the river, and people out on the lakes need to look out for submerged logs and debris.
He says people should also avoid the spillway areas downstream of the dams because there are strong currents which could flip a boat.
