Emergency authorities have downgraded an earlier emergency warning at Cape Otway and southern parts of Hordern Vale near Victoria’s Great Ocean Road on Wednesday.

A watch and act remains for people in Cape Otway, Glenaire and Hordern Vale to monitor conditions after firefighters were able to slow the spread of the blaze.

VicEmergency has issued a separate alert for the Blanket Bay Campground along the coast, warning people it is not safe to leave or return.

“Be aware of potential dangerous bushfire and tree hazards,” the warning said.

Apollo Bay Community Hall, east of the blaze, has been set up as an evacuation centre.

State government minister Colin Brooks warned those in the region the situation was developing and quite serious, urging people to keep up to date by checking the VicEmergency app.

The bushfire on the state’s coast comes after the popular Grampians National Park started reopening to visitors after a long-running fire blackened vast swathes of landscape.

The blaze has burned 76,000 hectares since being sparked on December 17 after dry lightning strikes in the southern part of the park, in Victoria’s northwest.

The entire park remains closed but Halls Gap, a village in its northeast, welcomed back visitors on Wednesday morning after authorities declared the fire contained.

Unaffected park areas will then reopen to visitors on Friday morning, including the northern section of the Grampians Peaks Trail from Mt Zero to Halls Gap, the popular MacKenzie Falls and Zumsteins Historic Area, the Stapylton and Smiths Mill campgrounds.

Further south, patrons will also be able to return to Mt Sturgeon, Mt Abrupt and the Victoria Range.

“We’re delighted to be able to welcome visitors back into the unaffected areas of the park,” Parks Victoria area chief ranger Charlie Richardson said.

There are still areas with active fire that have not been deemed safe to enter, with many roads and tracks remaining closed.

Returning visitors were advised to be cautious of smoke, fallen trees or branches and injured wildlife, and drivers warned they might encounter fire crews and heavy machinery on roads and tracks.

Four residential properties in Moyston and Mafeking were destroyed in the fires, along with 40 outbuildings in Moyston, Willaura, Willaura North, Mafeking, Pomonal, Glenthompson and Mirranatwa.

Grampians Tourism chief executive Marc Sleeman estimates the fire has cost the local economy more than $1.9 million a day and said the road to recovery for businesses would be long and tough.

More than 13,500ha of farmland has been burnt, 540km of fencing damaged and preliminary livestock losses tally 775 sheep, one horse, one cow and 1285 beehives.

Victorian Farmers Federation president Brett Hosking said it could take affected farmers two years to fully recover.