IGEM Report 1: 2017-18 - THE CYCLONE DEBBIE REVIEW

The Cyclone Debbie Review

The three concurrent events

Rockhampton – slow-onset flooding

Central Queensland is heavily reliant on, and strongly influenced by, the Fitzroy river basin, at 143,000 square kilometres the largest river system on Australia’s east coast. 66 Those familiar with the workings of the river system were alert to the potential impact of Debbie. Not only in its cyclonic phase, but as an ex-cyclone it had the capacity to drop substantial rainfall into the catchment and cause significant riverine flooding. Before Debbie crossed the coast, much rain had already fallen in some communities within the basin and one northern tributary (the Isaac River) was already at minor flood levels. In the days after Debbie made landfall there was further heavy rain, strong winds and localised flooding across Central Queensland. On Wednesday 29 March an EA was issued on behalf of Central Highlands Regional Council to warn of the potential for flash flooding. Two EAs were issued on behalf of the Banana LDMG on Thursday 30 March advising of rising water in the Callide and Kroombit Dams. Although the entire Banana shire had been officially drought-declared in early March, 67 memories of the release from Callide Dam in 2015 led to a desire by SunWater to provide early warning to the community. We were told the Banana local group was reluctant to send messages too early, and resisted their suggestions at first. However, the LDMG was very pleased with how SunWater managed the inflows and outflows of Callide Dam.

As Debbie passed over Central Highlands, Woorabinda and Banana on 29 March, taking a more easterly track than expected, these local government areas experienced rural flooding, road closures and crop, stock and equipment losses.

North Queensland

State-level operations

Central Queensland

South East Queensland

Flooding in the Central Highlands.

Photo courtesy of Central Highlands Regional Council

Activation matrix key Alert Lean forward Stand up Stand down

Central Queensland local and district disaster management group activations and state activations. Data sourced from SDCC, local and district disaster management group reports and interviews.

Group

sequence

Date, time

24 March, 10am

25 March, 10am

26 March, 2pm

27 March, 9am

28 March, 4.30am

28 March, 2pm

28 March, 7.15pm

29 March, 5am

29 March, 5pm

30 March, 1pm

31 March, 5am

31 March, 5pm

1 April, 5am

1 April, 1pm

2 April, 5am

2 April, 3pm

3 April, 5am

3 April, 5pm

4 April, 5am

4 April, 5pm

5 April. 5am

5 April, 5pm

6 April, 5am

6 April, 4pm

7 April, 5am

7 April, 4pm

8 April, 6am

9 April, 6am

10 April, 6am

10 April / 4pm

11 April / 6am

Livingstone Rockhampton Central Highlands Woorabinda Gladstone Banana

LDMG

Rockhampton Gladstone SDCC, SDCG, QDMC

DDMG

63

4 THE THREE CONCURRENT EVENTS

Rockhampton – slow-onset flooding: Map • Activations