Inquiry tries to understand the impact of dam operations on Victoria's 2022 floods

Victorian Water Minister Harriet Shing appeared before a parliamentary inquiry today (Wednesday) looking into the state's 2022 flood disaster.

Ms Shing was asked whether enough was done in the weeks before the floods to mitigate their impact, particularly in regional communities downstream of the big dams.

Member for Northern Victoria Rikkie Lee Tyrrell said the bigger water storages like Dartmouth, Eildon, Hume were "basically full" in September 2022.

Ms Tyrrell said at the same time the Bureau of Meteorology was forecasting heavy rains were likely across the state.

"There was going to be a lot of rain and the dams were already quite full," she said.

Dartmouth, the Murray River's biggest dam, spilled on September 22, 2022 for the first time since 1996 while at the same time the river's biggest operating, Hume, was 97 per cent full.

Today Dartmouth is at 99pc, Hume at 90pc and Lake Eildon is 98.6pc full.

The government's own submission to the inquiry said: "In September 2022, the (BOM) seasonal outlook identified a high likelihood of significant rainfall, and potential flash flooding and riverine flooding, between October 2022 and March 2023.

"Departments and agencies undertook planning, preparedness and readiness activities."

The submission said a "flood exercise" was held in its State Control Centre on September 19, 2022.

Victorian Emergency Services Minister Jaclyn Symes told the inquiry today she took part in that exercise which she said was "scarily accurate".

Less than a month later, parts of Victoria recorded rainfall totals between 150-300mm to spark the floods.

The dam operators were heavily criticised before, during and after the floods for not triggering higher releases to create the air space in the dams to capture some of those rain inflows and possibly mitigate the impact of the floods.

Victoria's water corporations are responsible for managing Victoria's major water storages, weirs and regulators.

The Murray-Darling Basin Authority is responsible for storages and structures on the Murray River and also manages the Dartmouth dam system.

Ms Shing said the dams were built to store water and not for flood mitigation, although that had become part of their role.

Member for Northern Victoria Wendy Lovell said many of the storages were full again today with more rainfall forecast across Victoria in the next few weeks.

Ms Shing said operators needed to consider many factors in making decisions on the operation of the storages.

She said the needs of licensed water holders was one consideration as was the impact of climate change and a drying climate.

Ms Shing said the government was investing heavily in helping water authorities and catchment management authorities update flood modelling.

She said it was important "all the data" from the floods was collated and shared to better prepare for future floods.

"We can't stop large volumes of rain coming into our system but we need an adequate response in place," she said.

In regards to the questions on the releases from the storages before the October 2022 flood, Ms Shing said she would ask for information to provide to the inquiry later.

The government's Environment and Planning Committee is investigating "Victoria's preparedness for, and response to Victoria's major flooding event of October 2022".

Farmers have already told the inquiry of the confusion and anxiety their communities experienced through conflicting messaging from authorities.

The committee has been told the cost of the 2022 flood disaster to Victoria's agriculture sector was estimated to be $1 billion.

Agriculture Victoria executive Dougal Purcell has said almost 500,000 hectares of agricultural land had been lost, close to 15,000 animals died and 12,000km of fencing was damaged.

Flood studies have identified the potential for about $115 million to be invested in a further nine flood levees in regional Victoria, two in Bendigo and others in Charlton, Violet Town, Wodonga, Numurkah, Seymour, Rochester and Maryborough.

A report from the inquiry is expected in June 2024.