Right now I am in Emerald, Qld., Australia with choppers droning constantly overhead in the middle of a flood event, having spent the last few days bagging sand for friends’ houses. I have been through this a few times now, having grown up in country areas.
I want to document how poorly BoM modeling has served the community during this event. No flood risk was projected initially.
Dec 25th: The main rain fell on Christmas day in the catchment, a widespread 4-6 inches.
Dec 27th: The Bureau of Meteorology advised that Emerald was facing a minor flood level of just under 3.5 metres over the spillway at the Fairbairn Dam within the next 72 hours.
Then a minor flood was predicted.
Dec 29th:Water should peak at the Nogoa River approximately midday Friday 31st December 300mm (12 inches/1 foot) above the 2008 level. This may close rail access.
Suddenly they panicked. Projections jumped 0.5 meters. On the basis of advice the Mayor ordered evacuation of 80% of the town.
Dec 30th: The flood height is estimated to get to 800mm or 0.8 metres above the 2008 flood levels to a peak of 16.2 metres . Residents in the red shaded area from yesterdays map 1 need to evacuate now to the Town Hall.
This was followed by a map covering 95% of the town. Evacuate a town of 10,000 people to a tiny town hall in 24 hours — yeah right.
Right now, 5:30pm on the 30th the flood gauge at the Nogoa River bridge has stabilized. I think this will be the peak at 15.85 meters. Fairbairn Dam will probably peak at 4.5 meters in the next few hours.
The BoM predictions started at 3.5m at the spillway on the 27th, kept rising daily as the water rose, then paniced and overshot by 0.5m on the final day.
A known amount of rain fell on a known terrain. It can’t be that hard.
All advisories here.