Good story Steve. Good to see the ADF has its priorities straight.
It should be interesting to see what happens. I was in Katherine in 1984 during an almost flood. Water levels reached a level ~30cm below the road surface on the bridge - higher than tonight. If the water goes over the bridge it apparently runs straight through the town. The high water levels were not such a problem back then. The town had a population of ~4000 back then vs the 10000+ now, so the town has sprawled considerably - no evacuations back then but there was considerable flooding in outlying areas. The town itself is the last place to get wet.
That river can change state in a heck of a hurry. A few weeks prior to that almost flood, some friends and I were jumping from the handrail on the bridge into a gently flowing channel ~20ft wide and about 10 ft deep. That is a loooong way down... around 20m. Young, dumb and... you finish the rest
The missus drove through yesterday on her way to the UK - now the roads are closed. Good thing she left a day early.
Oh yeah, those pictures showing the old railway bridge on the news.... there are some bloody big trees under all of that water between the two bridges - they'll survive.
Cheers