The council's 2018-19 annual report, which came before councillors at their October 28 ordinary meeting, said the council made 13.39 per cent of all its decisions at closed meetings. That is an increase from 10.95 per cent in 2018.

"Whilst the number of council decisions made that were closed to the public remained constant to previous years, less decisions were made at open council meetings, which is reflected by an increase in this ratio," the report said.

The report shows the proportion of decisions made confidentially is the highest it has been since 2016.

It did not provide an overall number of decisions made behind closed doors for any of the four years.

Only three regional Victorian city councils made more decisions behind closed doors in the same period - Ballarat with 22.4 per cent, La Trobe with 21.9 per cent and Mildura with 14.84 per cent. Wodonga council made 9.21 per cent of its decisions confidentially, with Geelong at 8.39 per cent and Bendigo 8.29 per cent.

Horsham mayor Mark Radford said many of the decisions the council made in confidence were the awarding of contracts.

"You might have one year where you're awarding 15 contracts, which are subject to personal information and stuff from businesses; whereas for the previous year, you might only award five. That would be another good example of why there are more confidential decisions one year than another," he said.

Cr Radford said each municipality had a different threshold for when it made confidential decisions on contracts.

He said Horsham council treated information about tenders confidential until after they were awarded, so the businesses could keep information they did not want competitors knowing private.

Cr Radford said councillors would attend an average of three briefings every month, along with an ordinary meeting of council open to the public.

RELATED: Sharp rise in number of council decisions made behind closed doors

"No decisions or debates occur at briefing meetings. It's all basic information-gathering," he said.

"Sometimes the officers might put up some recommendations and we might workshop those. It's an exchange of ideas and sometimes the recommendation will be different at the council meeting than it was at a briefing because we've discovered a way of doing it better.

"You can't go into a meeting with a fixed view that, 'No matter what happens, I'm not going to change my mind' - otherwise what's the point of having a debate? But it is important to come to a meeting having a full understanding of what's going on.

"Occasionally you'll see councillors ask questions of the officers on the night. That's OK, but it's preferable to do that leading up to the meeting."

Under the Local Government Act (1989), councils may resolve a meeting be closed if it discusses:

In December 2016, a Victoria Ombudsman report on council transparency said that some councils decided "almost all contractual matters in open meetings", but keep commercially sensitive material confidential. The report said the information subsequently released about contracts following closed sessions was also "highly variable".

Horsham Rural City Council's own meeting procedure states:

While you're with us, you can now receive updates straight to your inbox twice weekly from the Wimmera Mail-Times. To make sure you're up-to-date with all the news from across the Wimmera, sign up below.