Australia and New Zealand – More Rivers Overflow After Ex-Cyclone Debbie Rainfall

Rivers in Australia and New Zealand are still flooding as a result of heavy rain in the wakes of Tropical Cyclone Debbie which hit Australia over a week ago.

The Fitzroy River in Rockhampton, Queensland, exceeded the flood peak of 2013. In New Zealand, officials in the Bay of Plenty Region say the Whakatāne and Rangitaiki Rivers have experienced unprecedented 1 in 500 year flood events.

Cyclone Debbie

Cyclone Debbie made landfall along the Whitsunday coast on 28 March, causing wind damage and flooding in Bowen, Proserpine, Airlie Beach and Mackay.

Since then heavy rainfall in the storm’s wake has caused major flooding in south eastern parts of Queensland and north western New South Wales. At least six flood related deaths have been reported in New South Wales.

Queensland, Australia

Heavy rainfall that fell in the Fitzroy basin – the river catchment area of the Fitztoy River– some days ago made its way down river, causing Australia’s Bureau of Meteorology (BoM) to issue flood warnings earlier this week.

BoM Said “a major flood peak of 9.00 metres is likely at Rockhampton on Thursday morning. This flood level is just under the 2011 flood peak of 9.20 metres.”

Temporary flood barriers were set up in some areas of the city as a result of the warnings.

On Thursday 06 April the Fitzroy River in Rockhampton peaked at 8.75m. This exceeds the 2013 flood peak of 8.6m but is below the 2011 flood peak of 9.2m and and below the predicted 9 metres. However, low-lying areas of the city have been flooded and local media say more than 200 homes have been damaged.

Levels of the Fitzroy are expected to remain high for the next few days and affected areas of the city are likely to remain flooded for some time.

Port Curtis, Rockhampton after the Fitzroy River floods. Photo: Queensland Fire and Emergency Services

Bay of Plenty, New Zealand – 1 in 500 Year Flood

An area of low pressure containing high levels of tropical moisture left over from the remnants of Cyclone Debbie resulted in torrential rain in parts of northern New Zealand from 04 April, 2017.

The severe weather caused power outages and school closures. Wellington Airport was closed for a short time. Two districts of Whanganui and Rangitikei, both in Manawatu-Wanganui Region declared states of emergency ahead of expected flooding. Around 170 people evacuated their homes in Whanganui.

Since then rivers in the Bay of Plenty region of the country have overflowed, causing major flooding. Whakatāne District authorities said on 07 April:

“The Whakatāne and Rangitaiki Rivers have experienced unprecedented 1:500 year flood events. That has seen breaches of stopbanks on both rivers. The Whakatāne River level is continuing to subside. The Rangitāiki River flow is now falling, but significant flows will continue today.”

The Rangitaiki River overflowed in Edgecumbe city, forcing 2000 residents to evacuate their homes. Some streets were under muddy water up to 1.5 metres deep.

Local authorities said Edgecumbe residents will not be allowed to return until the flood waters and contamination concerns are controlled and the Medical Officer of Health has cleared the area as safe. It may be up to 72 hours (10 April) before people will be able to return to their homes.

Flood water has submerged roads in the area and about 2200 people in the communities of Minginui, Ruatāhuna, Te Whāiti and Rūātoki have been left isolated.

Bay of Plenty Regional Council flood manager Peter Blackwood said:

“Ex-cyclone Debbie rainfall levels were very high – on the Rangitāiki, sites logged between 200-320mm in 48 hours.”

The Rangitaiki River flow has reduced to 420 cu.m a second, down from 700+ cumecs yesterday, 06 April 2017.

Rangitaiki River flood. Photo: Bay of Plenty Regional Council

Flood summary

Last updated: April 7, 2017
Event
Tropical Cyclone Debbie, Eastern Australia and Northern New Zealand, March to April 2017
Date
March 27, 2017
Type
Coastal flood, River flood
Cause
Extreme rainfall

Locations

A - Bowen (Australia)
B - Airlie Beach (Australia)
C - Proserpine (Australia)
D - Mackay (Australia)
E - Beaudesert (Australia)
F - Tabragalba (Australia)
G - Logan (Australia)
H - Lismore (Australia)
I - Murwillumbah (Australia)
J - Chinderah (Australia)
K - Rockhampton (Australia)
L - Rangitikei (New Zealand)
M - Whanganui (New Zealand)
N - Edgecumbe (New Zealand)

Magnitude

Rainfall level
267 mm in 24 hours
Bowen, Queensland, Australia - March 28 to March 29, 2017
Rainfall level
166 mm in 24 hours
Carfax, Queensland, Australia - March 28 to March 29, 2017
Rainfall level
115 mm in 24 hours
Moranbah, Queensland, Australia - March 28 to March 29, 2017
Rainfall level
115 mm in 24 hours
Mackay, Queensland, Australia - March 28 to March 29, 2017
Rainfall level
191 mm in 24 hours
Sarina, Queensland, Australia - March 28 to March 29, 2017
Rainfall level
233 mm in 24 hours
Byron Bay, New South Wales, Australia - March 30 to March 31, 2017
Rainfall level
362 mm in 24 hours
Mullumbimby, New South Wales, Australia - March 30 to March 31, 2017
Rainfall level
298 mm in 24 hours
Woodburn, New South Wales, Australia - March 30 to March 31, 2017
Rainfall level
247 mm in 24 hours
Beaudesert, Queensland, Australia - March 30 to March 31, 2017
Rainfall level
285 mm in 24 hours
Canungra, Queensland, Australia - March 30 to March 31, 2017
Rainfall level
242 mm in 24 hours
Maclean, New South Wales, Australia - March 30 to March 31, 2017
River level
11.60 metres
Wilsons River at Lismore, New South Wales, Australia - March 31 to March 31, 2017
River level
6.2 metres
Tweed River at Murwillumbah, New South Wales, Australia - March 31 to March 31, 2017
River level
2.3 metres
Tweed River at Chinderah (Barneys Point), New South Wales, Australia - March 31 to March 31, 2017
River level
17.33 metres
Richmond River at Kyogle - March 31 to March 31, 2017
Rainfall level
74 mm in 24 hours
Taupo, New Zealand - April 4 to April 5, 2017
Rainfall level
60.2 mm in 24 hours
Gisborne, New Zealand - April 4 to April 5, 2017
Rainfall level
112 mm in 24 hours
Tauranga, New Zealand - April 4 to April 5, 2017
Rainfall level
72 mm in 24 hours
Auckland, New Zealand - April 4 to April 5, 2017
River level
8.75 metres
Fitzrpy River, Rockhampton, Queensland, Australia - April 6 to April 6, 2017
River discharge
700 cubic metres per second
Rangitaiki River, Edgecumbe, New Zealand - April 6 to April 6, 2017

Damages

Rescued
500 people
New South Wales, Australia - March 28 to April 3, 2017
Evacuated
20,000
New South Wales, Australia - March 28 to March 31, 2017
Fatalities
7 people
New South Wales, Australia - March 30 to April 3, 2017
Evacuated
2,000
Edgecumbe, New Zealand - April 5 to April 7, 2017