As lake levels are predicted to fall, council is asking boat owners to urgently remove vessels from the lake to avoid stranding and urging people to stay away from the opening during the first 36 hours, for their safety.

"During the opening we will be restricting boat access to the lake and only authorised officers will have access to Sandbar Beach," MidCoast Council water quality and estuary management co-ordinator, Prue Tucker said.

"Public access to the beach will be limited for safety reasons," she said.

Council has a policy to mechanically open the lake when it approaches 2.1 metres above sea level, an action outlined in the coastal zone management plan for Smiths Lake.

The opening level takes into account environmental outcomes as well as the prevention of minor flooding of property and roads.

"We've consulted key stakeholders, including local fishers, in reaching the decision to open the lake tomorrow," Ms Tucker said.

Smiths Lake water levels can viewed in real time data on the NSW Government website

You can keep an eye on Smiths Lake water levels with real time data on the NSW Government Manly Hydraulics Laboratory website.

Careful consideration is being given to the exact timing of tomorrow's opening on, Ms Tucker said.

Tides, swell conditions, predicted rainfall and lake levels will influence the effectiveness of the opening.

The Smiths Lake plan can be found on the MidCoast Council River, lake & estuary management page along with further information on the management of Smiths Lake and council's other coastal management programs.

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