A trickle of water, a mix of natural flows augmented with environmental flows released from the region’s storages, flowed into the lake last year, but for this year Mr Fennell predicted significantly higher inflows into the lake, north of Jeparit in the northern Wimmera.

“It’s hard to get a line on, but we estimate around 4000 megalitres a day have been flowing through Horsham, and there’s plenty more to come,” he said.

“We only just had the second peak in Horsham on Tuesday night, so it will continue to run for some time yet.”

The peak flow reached 6000 megalitres a day, a vast advance on the 2000 megalitre a day flow that made it up the Wimmera in 2009, the first natural flow for years.

The strong natural flow will mean water earmarked for environmental flows can be used in the late spring.

Mr Fennell said that as of Wednesday morning, flood flows in the Wimmera had gone through Dimboola and had reached the Arkona district, some 30km south of Lake Hindmarsh.

He said the flows would be left to wet up the whole of Lake Hindmarsh, rather than artificially banked up for recreational water.

“The Lake Hindmarsh system is as desperate for a drink as the Wimmera system was last year, so its important we let the water go down and flow into the lake as it would naturally.”

Meanwhile, the region’s storages have also benefited from the heavy rain, rising to 16.2pc, the highest levels for this time of year since 1999.

The inflows of over 25 gigalitres represented an astonishing weekly increase of over 25pc on levels week before, boosting the system’s storages from 95 to 120 gigalitres.

Lake Lonsdale alone recorded 11,780 megalitres in in-flows, raising it from 7pc to 25pc full in a week.

The Grampians Wimmera Mallee Water storage of Taylor’s Lake is as full as the authority wants it at 70pc of capacity, meaning flows from the Mount William Creek normally harvested for regional water needs, are now flowing into the Wimmera.

Water is also running down the Yarriambiack Creek, a distributary of the Wimmera.

Mr Fennell said water was north of the Horsham – Minyip Road at Kewell on Wednesday.