THE State's freight rail network suffered significant flood damage from wild weather Friday and over the weekend, with some lines, including the main interstate line, still closed this week.
CBH Group's grain trains were impacted from late Friday afternoon when concerns about rising water and potential track undermining caused network operator Brookfield Rail to close lines as a precaution.
CBH operations logistics manager Ben Raisbeck said the co-operative's sites had also been affected, with the Borden site significantly impacted by flooding.
An assessment was underway to reveal the full extent of damage.
"Grain was under fumigation, so we need to wait to get clearance before we can access the storages and assess the damage to grain, but we will attempt to move the grain as soon as possible to prevent any further damage," Mr Raisbeck said.
Some northern grain lines, including the Kalannie line, and grain lines through the lakes district to Hyden and Newdegate were shut down, a Brookfield spokeswoman said on Monday.
The northern lines have since been reopened, but the eastern lines remained closed on Monday the spokeswoman said, with track crews having difficulty getting in to inspect potential damage because of localised flooding and soggy ground.
Significant damage was suspected to the tracks and their foundations which skirts salt lakes and low-laying areas.
The Great Southern Railway operating from Northam to Albany was also closed with sections of the track between York and Wagin damaged, while woodchip operations closer to Albany were able to resume, the spokeswoman said.
The main Perth-Kalgoorlie Eastern Goldfields Railway was closed between Northam and Kalgoorlie to all rail traffic, she said.
The main disruption was damage caused to the track's formation between Northam and Grass Valley, with repair crews having to construct new access roads to get to the damaged tracks.
The spokeswoman said a section of line further east through low country towards Merredin was also a concern.
While Brookfield Rail declined to nominate when the standard gauge line might reopen to interstate freight trains, grain trains and the Indian Pacific passenger train, the Public Transport Authority has said it hopes to have Prospector, MerredinLink and AvonLink trains operating today.
The Leonora line from Kalgoorlie also remained closed, the Brookfield spokeswoman said.
"There has been extensive damage to the rail network, including embankments, track structures and access roads," she said.
"Brookfield Rail's teams (have been) working to assess the extent of the situation and plan for safe restoration of the railway and train operations as soon as possible."
In some areas damage had been repaired and lines reopened but in other areas continuing rain had hampered repair work, she said.
She said Brookfield Rail was working closely with customers who use the rail network to ensure they were kept informed of repairs progress.
CBH operations manager David Capper confirmed roads and rail transport to ports had been disrupted by the unseasonal weather and vital ship loading schedules were impacted.
"Since Thursday there has been significant rainfall across the Kwinana, Albany and Esperance Port zones," Mr Capper said.
"This rainfall is affecting CBH Group's operations with both rail and road transport and ship loading impacted.
"In the Kwinana and Albany port zones we have had limited ability to move grain via road or rail since Friday morning.
"We are working closely with our customers, freight operators and infrastructure stakeholders to understand and minimise the impact of flooding and subsequent delays to our operations.
"Our focus is on ensuring the safety of all involved in the movement of grain throughout the network while managing this weather event."
At this time of year CBH has ships waiting at anchor to load wheat, barley and canola at its port terminals not only for its own marketing division, but for customers Louis Dreyfus, Glencore, ADM Trading, GrainCorp and Bunge.
Timing and a smooth flow of grain through the ports is essential for CBH to get grain to northern hemisphere customers during the prime supply time of the northern winter.
There is little opportunity to reroute ships at short notice to alternate ports with spare capacity and stockpiles of grain.
CBH's Kwinana terminal shipping stem listed five ships scheduled to be docked and loaded with wheat, barley and canola this week.
Another three ships were scheduled to dock and load at CBH's Albany terminal and a further three at its Esperance terminal.
Mr Raisbeck said as well as the heavy rains affecting the movement of grain in the network, the rain had also delayed loading at port.
"Vessels can't load at the port when raining because the grain can get wet so loading the ships becomes difficult," he said.
"We are lucky that we have storage at the port terminals so for the current vessels that are waiting we have the majority of stock but the rain will impact over the whole month as we have gone through a four to five-day period where we haven't been able to accumulate much grain at the port so there will be a flow-on effect.
"Considering the size of the event and the closures put in place we don't think there's going to be major delays but there will be some vessels affected."