The crucial weir at Mildura has been replaced in the Murray River.
River levels are now expected to slowly rise again to ease water restrictions across the region.
Water authorities have been accused of waiting too long to reinstate river flows after the flooding emergency had passed.
Emergency water restrictions have been eased to Stage One in Gol Gol and Buronga near Mildura.
Wentworth Shire Council last week imposed restrictions for town residents because of low water levels in the Murray River.
The restrictions were seen as "crucial" to provide drinking water supplies.
A blue green algae alert has been issued for water users in Mildura and district.
Water authorities removed weirs along the length of the Murray during last year's floods to prevent damage to the expensive structures.
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The Murray-Darling Basin Authority and Goulburn-Murray Water have been are working to reinstate the Mildura weir and Lock 11.
The weir was removed back in September to prepare for the flood peaks which travelled the length of the river and has now reach the river's mouth in South Australia.
The weir was winched out for the first time since 2016 to allow the flood to pass and minimise the risk of damage to the infrastructure.
Flooding also forced the historic lifting of the barrages near the Murray's mouth in South Australia for the first time since the 1970s.
WaterNSW has also been reinstating the weir at Wentworth.
The weir pool reached full supply level late last week, and inspections would commence shortly to reinstate Lock 10.
At Euston, Lock 15 was expected to reopen to all river users in the coming week, and the weir pool would be raised to full supply level once current works were complete.
River pumpers and houseboat operators in the region are advised to continue monitoring river levels closely during this period.
The weir pool at Mildura will return to its usual level over the coming week as work to reinstate the Mildura weir nears completion.
The weir's 24 trestles have now been successfully re-installed by Goulburn-Murray Water, supporting a steady rise in the river to full supply level later this week.
Murray-Darling Basin Authority executive director (river management) Andrew Reynolds, said GMW crews had been working around the clock to get the weir back in.
"With the trestles re-installed, there is further work to be done before the boards begin to be put back in later this week, which will enable us to start to refill the weir pool," Mr Reynolds said.
"When the boards are back in, people should expect to see the river level rise upstream of the weir.
"We understand how important the river is to community and industry and want to thank everyone on both sides of the river for their patience. It's been a testing time, coping with flood waters and then the time needed to safely return our river infrastructure to full working order."
GMW has also started inspections and assessments to restore Lock 11 and anticipate that the lock will be open later in the month.
No river users are allowed to pass through this section of the river until works are complete.