They know that in comparison they are the lucky ones, but there's no denying the East Coast Low that hit this week has put heavy rain on crops and left levy banks overflowing into farms.

The Hunter River is continuing to rise downstream from Oakhampton as flows from the Singleton area make their way down, and that has some farmers feeling a bit nervous.

At Nebo Farm, on the Hunter River at East Maitland, it's clear the thousands of seedlings they planted in early February are now either dead or almost at the point of no return. Only a small portion are hanging on, for now.

But farming duo Matthew and Liam Dennis remain upbeat, saying it could have been a lot worse.

"Some of the seedlings have died - that rain was too much for them and they drowned," Matthew said.

"Heavy rain and no sun, that's the biggest killers."

Their zucchinis, peas, some of their lucerne, carrots, corn and beetroot are among the casualties.

At least 80 per cent of the carrots are ruined. The potatoes are looking sick and may not survive.

Even the cheerful sunflower crop is struggling to find the positives amid a sea of water.

Flood water continues to overtop the levy bank at a steady pace and is slowly engulfing the fields.

"It's still coming up, it has come up four inches [10cm] this morning and it's started breaking through into Phoenix Park," he said.

"I do think we're at the peak but Greta has been at the same level for 36 hours now and there's a lot more water that's going to have to make it's way down through here."

"We've lost about 30 acres of lucerne at this stage."

The Dennis duo are waiting for the higher ground to dry up so they can plant about 15,000 seedlings that have arrived at the farm.

"We're going to have a three week gap where we've got nothing to harvest, but that's just the way it is," Matthew said.

Nearby at the Osborn family farm on the Hunter River at Pitnacree and a breach in the levy wall has Steven Osborn worried.

The wall is designed to keep water out of their farm as long as the river level at the Belmore Bridge in Maitland is below 9.5 metres.

The water has been coming in even when the level was around 9 metres.

"There is one bit of levy bank overtopping at the moment and we are living in hope that the water has peaked," Mr Osborn said.

"We thought we were safe up to 9.5 metres and it's around 9.3 metres now at the Belmore.

"Now there has been a breach we are going to have to wait and see how much water comes in over the next 12 hours."

Some of the lucerne crop is being inundated as well as some of the pumpkins and corn.

The Osborn's potato patch is also struggling with wet feet - thanks to a deluge from the sky - and they are unsure if the crop will survive.

"The corn may be tall enough in terms of the cob height to tolerate the water but we are expecting some losses," he said.

"It's a little bit early to say what will eventuate. There is still a lot of water in the Singleton area and until Greta starts to fall we will breathe a little easier."

North at Oakhampton Heritage Farm on the Hunter River and farmer Austin Breiner can see the river is still stationary - and it has been like that since Thursday.

"The river doesn't seem to have fallen here at all. It's not inundating much of our place though and it hasn't reached the veggie patch, although all of that rain we have had has destroyed it anyway," Mr Breiner said.

"That heavy rain has made the ground waterlogged and all the roots have gone rotten and they've died.

"All that is left is a few cucumbers, a row of beans and a few rosellas, and a few pumpkins."

Mr Breiner had taken advantage of the cool and wet summer and got a head start on his winter vegetable crops.

Now all of that has been wiped out and he must start raising seeds again before planting them out.

"It's the way it happens. I went out there yesterday and I was sinking down to my ankles in mud," he said.

In other news:

Maitland, Cessnock LGAs, declared a natural disaster area

Hinton kept supplied with kegs and all

Singleton starts to re-open after flood

Two Hunter women die from COVID-19

Hunter River nears its peak