Toowoomba and the waiting game

No one watching the video footage of the flash flood in Toowoomba on the news last night could not have been shocked as the Dinky-Toy cars and vans were hurled against trees by the raging brown flood wave and bystanders waist deep in water looked on helplessly.

Everyone's heard about the devastating floods further north in the state in the last few weeks, and now the warnings for the southeast, plus seemingly endless forecasts of more rain, but this surge came (and went) so rapidly that even hardened, unflappable Queenslanders were shocked.

Toowoomba lies 127km west of Brisbane, at 600-700 metres above sea level on the edge of the Great Dividing Range. It is an important regional centre serving the Darling Downs. No one anticipated what happened in the city's central business district yesterday. Despite weather-forecasting and flood-predicting computer models and Bureau of Meteorology hydrologists working 24 hours a day, several local factors conspired to create a relatively small-scale event that wasn't picked up until emergency services received calls.

A super rainstorm produced by a high-level low dropped 80mm in half an hour as uplift on to an escarpment intensified a weather system that would not itself have been extraordinary had it not combined with excessive runoff in the Lockyer Valley (where soils are saturated) to produce rapidly rising rivers and creeks.

As I write, eight people are known to have died in Toowoomba and 72 people, included entire families, are unaccounted for in the Lockyer Valley.

All that water is now headed for the state capital. Several currently swollen Darling Downs rivers join the Brisbane River just below the Wivenhoe Dam, built after the devastating floods of 1974. The Brisbane's own catchment is huge, and a greater volume of water has rained down lately than preceded the '74 floods. The reservoir is currently at 173% capacity. The predicted high for the river level in the city tomorrow – at high tide and with spillage from the dam – is estimated at the moment to be almost as great as in '74. Figures are constantly being updated.

And so in Brisbane and the southeast we wait. As the people of Emerald and Rockhampton, and Bundaberg and Theodore and Maryborough and Gympie did before us. And still it rains. We have become accustomed during the big wet of the last few months to checking the Bureau of Meteorology's radar map (top) to see what is heading our way. There is small consolation to be had at the moment.

In this part of the world, rainstorms can last for hours, even days, but sooner or later the sun banishes massive grey accumulations. That hasn't happened for a long while here. For eight days, sun glimpses have been few and far between. Tomorrow, forecasters say, rainfall will ease, but that won't affect the surge headed my way. Bulimba is on the at-risk list (below, the river at 2.30pm today).

By mid-afternoon, there was lots of activity everywhere: people hurrying home from work; a stocking-up of supplies in the supermarkets (by the time I went for a few things there was already no bread, no bottled water and very little milk); sandbags being unloaded and placed in position; and our favourite riverside restaurant being evacuated. And all the while, people were taking up vantage points down by the riverside to stand and stare (my friend holds the red and green Basque umbrella on the jetty below); and to witness the turbulent flow and debris already hurtling towards the ocean on what they knew would be yet another historic moment in the flood history of this city.

Bulimba ferry terminal

By now parts of West End were flooded and department stores in the CBD were shutting up shop as the waters crept ever nearer to the city's heart. The Port of Brisbane closed.

At home, we began countless stair climbs laden with books, smaller pieces of furniture, food supplies, rugs, ornaments, paintings, lamps, candles and mozzie-zapping supplies. As State Premier Anna Bligh gave the first hint that river levels might reach 1974 limits, my friend calculated that would mean half-way up our ground-floor walls. We hastened the evacuation upstairs.

We walked down to the river at about 9.30, drawn irresistibly. Pockets of people, huddled under umbrellas still, stared at the torrent as if searching for an answer, or willing the waters not to rise any further. But the silence was palpable.