Favourable conditions on Monday helped crews contain the massive Grampians blaze, which had burnt more than 53,000 hectares by Tuesday.

But the Department of Environment and Primary Industries issued a watch and act message for Stawell and the Black Range on Tuesday night as a bushfire continued to burn about seven kilometres south of Stawell.

Unexpected conditions caused the fire to cross containment lines.

Meanwhile, crews were also working to contain fires in the Mallee, which have burnt more than 90,000 hectares.

Department of Environment and Primary Industries, Country Fire Authority and Parks Victoria fire-fighters used air attack and ground resources to continue building containment lines around the fires.

Fire-fighters in the Grampians also had to deal with a number of explosions in the St Helen’s Plains area while fighting the Grampians blaze on Saturday.

CFA strike teams were in the area trying to save farm houses when fireworks and a drum containing flammable liquid stored in a shipping container exploded.

The CFA is working to allow residents back into the Roses Gap and Wartook areas.

Horsham Incident Control Centre spokeswoman Jenny McGennisken said residents were advised at a meeting in Laharum on Tuesday that hazardous tree assessments must be completed before they would be allowed home.

“Personal safety is a priority – not only for residents, but also for our fire-fighters,” she said.

The fires and extreme temperatures have also caused water issues across the region.

GWMWater spokesman Andrew Rose said water issues during the fires were a result of an unlikely set of circumstances with large fires in both the Wimmera and the Mallee.

“The system operated in general really quite well under the circumstances,” he said.

Mr Rose confirmed Pomonal ran out of water on Friday because of a burst main. 

He said residents who decided to stay and defend their property should always have their own water supply.

“We’ll do whatever we can, but we’re never going to put our staff at risk,” he said.

He said Halls Gap and Pomonal had switched to non-potable water to ensure the maximum availability of water if power was lost.

Mr Rose said asset losses sustained by GWMWater were not going to be a significant cost and about 30 air valves had already been replaced.

At Lake Wartook, GWMWater lost the caretaker’s residence in the blaze. 

In coming days the authority will investigate if any other assets had been lost.

Mr Rose said one of the main issues for GWMWater during the fires was working with thinly-stretched resources as people were sent to two major fires.

“We learnt a lot from the 2006 fire – you can always do things better,” he said.

“It was a huge resourcing issue this time. We were very stretched – we coped and coped well.

“It was logistically challenging.”

He said GWMWater would review its processes to look for opportunities for improvement when coping with high demand and crisis situations.

“On Thursday we’re sitting down to have an internal debrief and examine if there are things that we can do better,” he said.

Opposition leader Daniel Andrews will tour fire-affected communities on Wednesday.

Premier Denis Napthine visited Horsham, Brimpaen and Stawell on Saturday and visited the Wimmera again on Tuesday.