Mary came up fast but left the city slow
THE suddenness of the flood that engulfed the Gympie region last weekend, the vast volume of water deposited here - 600mm of rain in some areas - and its sluggish departure have distinguished Gympie's fourth flood in three years as one of its more unusual.
Gympie Mayor Ron Dyne said yesterday the Mary River rose at a rate of almost a metre an hour on Sunday (900mm), almost four times faster than most previous floods, where the water came at a rate of about 250mm an hour.
This was phenomenal in itself, but further west, the Boonara Creek at Boubyjan rose 6m in four hours.
At the height of the flood, Boonara Creek was 1.4km wide, the mayor said.
Once the Mary River peaked at 20.3m back in Gympie, she took her sweet time to recede, dropping agonisingly slowly over two days, cutting off the 5-6000 Gympie residents who live on the "other" side of the river and leaving a thicker than usual layer of silt and sand over the region's paddocks, public facilities, roads and businesses.
A rancid stench emanated from the receding flood waters yesterday, and the tilted roof of the Sound Shell in Nelson Reserve illustrated the thick sediment left behind, with the highest tip of the roof its usual dark grey, but the rest of it a striated brown.