Queensland Floods 2011: Causes, Effects, And Flood Inquiry Reports

This unit develops the student’s expertise in engineering project management including professional ethics and legal obligations and their research and presentation skills. It will be achieved through employment of appropriate research skills on a capstone project which demonstrates student’s professional expert level of identifying and planning an engineering project.

Outcome

1 Critique technical publications;
2 Present written professional/technical reports;
3 Examine Engineering profession and the environment in which these professions operate;
4 Apply the process involved in contract and project management in Engineering industry via capstone project;
5 Analyse risk situations in an engineering project and manage them by applying the theories of risk management; and
6 Apply WH&S requirements to an engineering project

Causes of the Flooding

In January 2011, the state of Queensland experienced the biggest natural disaster witnessed over the last decade. The floods begun as early as December 10^th, occurring in various parts of the state but the most damage occurred when the Brisbane River flooded between the 10^th and 13^th of January. The aftermath of this was widespread havoc which resulted in loss of life and property of some of the resident of the areas surrounding the river. Up to date, 37 deaths have been recorded in relation to the floods while the financial damage caused, both in properties lost and in flood mitigation costs exceeded 10 billion AUD. With a commission having been set up to investigate the causes of the flooding and provide a managerial way forward, a lot of information has been collected which details the cases of the floods and the extent of the damage.

In early 2010, meteorologist reports were released warning of the impending La Nina rains.  The La Nina is naturally associated with heavy rainfall and during this period, the state witnessed an average precipitation level of 4.04m. These were the highest precipitation levels recorded since the 1975 flooding (van den Honert and McAneney, 2011). The la Nina fears were later qualified when Cyclone Tasha, a tropical cyclone hit the North Western part of Australia, roughly 1,600 kilometers from Brisbane, heading south towards Brisbane. The cyclone led to increased levels of rainfall with this water accumulating over time behind the Somerset and Wivenhoe dams. Up till then, the main flood protection system in Brisbane had been Wivenhoe and Somerset dams which reached their capacity sooner, owing to the prolonged rainfall season.

By December 2010, the cyclone had brought about so much rain that troughs joining the Brisbane and Bremer Rivers at different points had significantly increased the water level of the two rivers. This contributed to the creek rising and flash flooding of the surrounding areas when the intense localized rains came. The damage caused by this rainfall was spread over Eastern Australia and as the cyclone and La Nina rains moved towards Queensland, the more severe the effects of these flooding became. Between 10^th and 13^th January, having accumulated excess water from the rainfall and the River’s capacity, Somerset and Wivenhoe dams gave way causing downstream flooding along the river. The flooding of these dams contributed to 59% of the recorded damage. So far, the flash flooding of rivers due to heavy rain and the downstream flooding of the dams have been the only recorded causes of the flood.

The effects of the flooding include loss of life and property. With a total of 37 record deaths over the entire flooding event, 23 occurred in the Toowoomba and Lockyer Valley which were nearest to the dam location. The flood contributed to loss of property where over 26,000 residential properties were affected with 60% of the figure being destroyed completely that was a staggering 4.2% of the entire city’s population. The financial implication of the flooding was roughly 12.5 billion AUD which includes economic losses (van den Honert and McAneney, 2011).

Effects of the Flood

Another great effect of the event was the realization of the poor mitigating measures that the state of Queensland had put up in order combat such an event. It exposed various flaws in the various Australia’s disaster management systems it had in place. With people unprepared for the flooding, the effects of the floods were greatly felt as there was a very tiny response window (Stoney, 2012). With the “dam release flood” itself happening over the whole duration of the whole 3 days, people had very little time to secure property and belongings. The insurance industry also suffered huge losses due to payouts in some areas where individuals had lost property and those that needed environmental healthcare services too.

Numerous flood enquiry reports have been published by engineers and other professionals. A study of the interim report for instance suggests that the warning about the La Nina floods had been carried out by the meteorological department as early as June (O’Brien, 2011). It however generalizes the 2 causes of flooding into one suggesting that the same heavy rainfall that caused the flash flooding had direct influence on the “dam release floods”. It suggests that the rainfall was too intense that, as it caused the rivers to swell, these in turn fed the dams at a much faster rate than it had the capacity for.

Engineers John Hayes and Ashantha Goonetilleke suggest that the spatial information systems had not been fully utilized and therefore could not be of much help in resident protection apart from assisting in obtaining weather information (Hayes & Goonetilleke, 2012). They suggested the implementation of a system that would map out the flood lines and the extent of the flooding. The Queensland Surveying and Spatial Sciences Joint Natural Disaster Response Committee suggested through their report, a system where individual property owners would be able to access spatial data in order to be able to make the necessary arrangements should a similar flood occur (Q. S. S. S. J. N. D. R. C, 2011). While it may not stop the floods, their report argues that having this information would help them be ready.

In his submission, Alex Stoney. Points out that having more flow cross sections of the various streams and rivers would be helpful to any flooding related planning that would be concerned with the volumes of water flowing (Stoney, 2012). He also suggests deepening the channels by cutting trenches in the river’s lower extents much like dredging is done on artificial harbors to increase their depth for easy ship accommodation. A report by John Craig suggests the modification of dam itself by increasing the capacity to mitigate floods by increasing its wall height. Should that fail, he suggests reducing the amount of water coming into the dam itself. Should that fail too, a new dam would be constructed (Craig, 2011).

Our expression of interest to build a buffer dam is because we believe it would be more cost effective approach to protecting the individuals and households of areas prone to flooding. We believe that such a dam would be able to alleviate the pressure on the 2 dams and water could be redirected to it. The reason we believe it would be cost effective is that it can be regarded as a permanent solution. This would permanently reduce the amount of water coming into the dam. Pricing information is as follows:  

Table 1: OVERALL PROJECT COST

Conclusion

We believe that it is possible to protect the city from similar natural disasters at a much cheaper cost than it would take to react to it. The water abstracted from this new buffer dam could supplement the power supply system thereby increasing environmental friendliness. It is also possible to utilize the water for municipal watering to save on the costs of water. Furthermore, to prevent the overuse of this water, sluice gates or weirs could be constructed along the channel to ensure that only excess water is stored and used in this dam.

References 

Alam, K., Rahman, A., Ranaweera, K. & Markar, S., 2014. Establishment of a hydrological benchmark for mitigating urbanisation impacts at Logan Village, South-east Queensland. Barton, A.C.T. , Engineers Australia, pp. 774-781.

Australian Bureau of Meteorology, 2010. La Nina increasingly likely for 2010, s.l.: Australian Bureau of Meteorology.

Bohensky, E.L. & Leitch, A.M., 2014. Framing the flood: a media analysis of themes of resilience in the 2011 Brisbane flood. Regional Environmental Change, 14(2), pp.475-488.

Chen, K., 2011. Risk Frontiers, West Perth: NearMap Pty Ltd.

Cheong, F. & Cheong, C., 2011. Social Media Data Mining: A Social Network Analysis Of Tweets During The 2010-2011 Australian Floods. PACIS, 11, pp.46-46.

Craig, J., 2011. South East Queensland Flooding, January 2011, Queensland: Queensland Floods Commission of Inquiry.

Hayes, John & Goonetilleke, Ashantha, 2012. Building community resilience – learning from the 2011 floods in Southeast Queensland, Australia. In Kakimoto, Ryuji & Yamada, Fumihiko (Eds.) 8th Annual Conference of International Institute for Infrastructure, Renewal and Reconstruction : International Conference on Disaster Management (IIIRR 2012), Kumamoto University, Kumamoto, Japan, pp. 51-60.

Hossain, S. M. A., Rahman, M. M. & Rahman, A., 2017. Queensland Flood in 2010-11: Will This Type of Flood Occur Soon?. Minto, N.S.W., s.n., pp. 102-108.

Insurance Council of Australia, 2011. Flooding in the Brisbane River Catchment, January 2011, Sydney: ICA Hydrology Panel.

O’Brien, M. J., 2011. Brisbane Flooding January 2011—An Avoidable Disaster, Brisbane: Queensland Floods Commission of Inquiry.

Queensland Flood Commission Inquiry, 2011. QFCI Interim Report, Chapter 1 Summary of weather and flood events, Queensland: Queensland Flood Commission Inquiry.

Queensland Floods Commission of Inquiry, 2012. Final Report, Queensland: Queensland Floods Commission of Inquiry.

S. S. S. J. N. D. R. C, 2011. A submission to the Queensland Flood Commission of Inquiry by Queensland Surveying and Spatial Sciences Joint Natural Disaster Response Committee.

Quilty-Harper, C., 2011. Australia floods: what caused the flooding?. [Online] Available at: https://www.telegraph.co.uk/news/worldnews/australiaandthepacific/australia/8254976/Australia-floods-what-caused-the-flooding.html
[Accessed 25 Aug 2017].

Stoney, A., 2012. Control of Future Floods - Add 1., Queenland: Queensland Floods Commission of Inquiry.

van den Honert, R.C. and McAneney, J., 2011. The 2011 Brisbane floods: causes, impacts and implications. Water, 3(4), pp.1149-1173.