The Murray Darling Basin Authority (MDBA) says irrigator demand for water allocation has dropped following widespread rainfall and storms across the Basin.

Parts of the Western Plains have recorded over 100 millimeters of rain since around mid-November.  

The Authority says the Barwon River at Collarenebri has seen daily flow reach 45,000 mega litres, with those flows being seen in Bourke as at Monday mid-afternoon.

"The recent rainfall across eastern Australia has seen a temporary rise in river levels and reductions in irrigation demand, and storage releases. Further down the system, Lake Victoria is almost full – ready to support what is expected to be a high demand summer autumn," MDBA Executive Director of River Management Jacqui Hickey said.

“The updated Annual Operating Outlook (AOO) issued today (11 December) reaffirms our confidence to deliver water where and when it is needed this water year."

Irrigators and wetland graziers welcomed the extra water.

"Most irrigators along the Barwon-Darling have got summer crops in and they've got enough water before the rain had enough water to get their crops through," said Ian Cole from Barwon-Darling Water, which represents irrigators along the river," said Ian Cole from Barwon-Darling Water, which represents irrigators along its namesake.

"There'd be one or two they may not have, so obviously it's going to be a benefit to them, but the real benefit will be that they'll be able to now put a little bit more water away for a winter crop or next year's crop."

Barwon-Darling Water's Ian Cole. IMAGE: supplied

However, an MDBA spokesperson said higher flows occurring rapidly due to recent weather could lower oxygen levels for fish.

When more dead leaves and plant material end up in the waterways, bacteria uses more oxygen as they break it down.

That can lead to fish kills like this week in Walgett, especially in Summer when temperature rises also decrease oxygen levels in the water.

Authorities from the Department of Primary Industries and Regional Development believe the temperature and high flows is likely what caused the kill.

"We are working with jurisdictions as they monitor for a range of water quality risks," the MDBA spokesperson said.

The rains have also given graziers in the Macquaire Marshes a reason to smile.

For graziers Leanne and Garry it means they will be able to maintain their cattle stock numbers through the summer

"With the local rain, combined with the inflows into the Macquarie downstream of Burrendong, it's provided a whole new pulse of water moving down the river," Mr Hall said. 

"We're coming to the end of our Joining now, so we'll be getting our bills out over the next few weeks and it's given us lots of options."