FLOOD FODDER: Rain heading for Mary River catchment

"Gympie in the past has had some pretty big floods,

1999 FLOOD Gympie residents near Kidd Bridge on the evening of Monday the 8, as the Mary River steadily rose, few realised what was about to happen over the next 24 hours. Picture: Renee Albrecht

UPDATE Thursday 1pm:

ALL EYES are on the Mary River while the Bureau of Meteorology retains a flood watch on it ahead of today's severe weather event which could see up to 400mm dumped in the Gympie and Sunshine Coast regions.      

Bureau senior hydrologist Andy Barnes told The Gympie Time earlier today we "could see some flooding in the Mary catchment in the next day or two," but he could not commit with any certainty.

FULL FREE GT WEATHER COVERAGE:

• ROLLING COVERAGE: Which roads are closed in Gympie?
• SHOPPING CENTRES: "Business as usual" as supermarkets open
• RAINBOW BEACH: 120km/h winds, widespread erosion predicted
• SCHOOLS OUT: Schools closed from Agnes Water to border
• CANCELLED: Gympie sport set for soggy week

"Gympie in the past has had some pretty big floods, but obviously we have still got a lot of rain to come," he said. 

He said the rise of river will really depend on how localised the rainfall in the Mary River catchment, particularly in the river's headwaters around Mapleton and Maleny which directly affects amount of water converging downstream to Gympie. 

MORE ON THE MARY CATCHMENT: Anatomy of a Gympie flood

Maleny received 142mm overnight and Mapleton 86mm and both areas were predicted to receive up to 250mm today.  

WEDNESDAY: 

Let's get technical: What are the chances of the Mary flooding?

AS THE Mary River remains on flood watch ahead of a predicted huge dumping of rain in South East Queensland tomorrow, the real question is: just what are the chances of Gympie flooding?

Whether the Mary River rises to inundate Gympie homes, businesses, roads, parks and sporting facilities like it has so many times before depends on how much rain falls over the Mary River catchment.

FULL WEATHER COVERAGE:

• CANCELLED: Gympie sport set for soggy week
• WIDE BAY ROAD CLOSURES: Here is every road closed due to flash flooding
• FIRST PHOTOS:Hamilton Island ravaged by Cyclone Debbie

The Bureau of Meteorology says if 200mm or more falls in the catchment around Maleny and Mapleton in 48 hours then Gympie will most likely be in for a moderate to major flood- if the figure increases to 300mm in the same time period then a major flood is likely.

Forecasters says the Mary River catchment is in the same firing line as Gympie tomorrow - with a huge downpour of up to 150mm expected to be dumped on the region in less than 24 hours - figures that come close to sounding like the ones used to predict floods.

Aerial photos of Gympie floods

VIEW GALLERY

While Bureau of Meteorology forecaster David Blazak was reluctant to predict whether the Mary River would flood when he talked to The Gympie Times earlier today he did say there was a risk.

He said hydrologists at the Bureau will be monitoring rising river levels in south east Queensland and will be providing updates and warnings tomorrow as the weather event unfolds.

Rainfall measured over the region including Gympie. Picture: Contributed

QLD WARNING:Floody hell: 1400km-wide storm warning for Queenslanders

Flood heights are predicted for the Mary River at Gympie whenever it is expected to exceed 12 metres on the gauge boards adjacent to Kidd Bridge.

The BoM aims to provide between 21 to 27 hours warning to the Gympie public of flood heights above 12 metres with the forecasts updated up to six times per day throughout the flood event.

Mary River Basin map: Flood warning network. Picture: Contributed

Flood Classifications:

Minor Flooding : Causes inconvenience. Low-lying areas next to watercourses are inundated. Minor roads may be closed and low-level bridges submerged.

In urban areas inundation may affect some backyards and buildings below the floor level as well as bicycle and pedestrian paths. In rural areas removal of stock and equipment may be required.

Moderate Flooding: In addition to the above, the area of inundation is more substantial. Main traffic routes may be affected.

Some buildings may be affected above the floor level. Evacuation of flood affected areas may be required. In rural areas removal of stock is required.

Major Flooding: In addition to the above, extensive rural areas and/or urban areas are inundated. Many buildings may be affected above the floor level.

Properties and towns are likely to be isolated and major rail and traffic routes closed. Evacuation of flood affected areas may be required. Utility services may be impacted.

CANCELLED: Gympie sport set for soggy week