Related - Floodplain Manager May 2021

Watershed in Federal Flood Funding

The 2021 federal budget has taken a new direction in making Australia more disaster resilient and improving preparedness, response and recovery.

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Firstly, a new National Recovery and Resilience Agency will be established. The agency will incorporate various flood, drought and bushfire relief programs across the country including the former National Drought and North Queensland Flood Response and Recovery Agency and the National Bushfire Recovery Agency, including the $2 billion National Bushfire Recovery Fund. The agency will also be responsible for supporting the long-term recovery of communities rebuilding after the recent storms and floods in NSW and Queensland, and cyclones in West Australia.  A further $600 million has been pledged to be administered by the agency to be invested in disaster preparation and mitigation.  An additional $210 million has been put towards a new Australian Climate Service that will bring together data from the Bureau of Meteorology, CSIRO, ABS and Geoscience Australia.

The Government is also providing $90 million to enhance Emergency Management Australia’s capabilities to improve national disaster preparedness and response. This includes facilitating resource sharing decisions with the states and territories. Affordability of insurance in Northern Australia has been backed by an annually reinstated $10 billion government guarantee. The funding will establish a cyclone and related flooding reinsurance pool which aims to increase insurance availability in high-risk areas by helping insurers manage their exposure to cyclone risk. In addition, a North Queensland pilot has been announced which provides $40 million in funding to subsidise the cost of cyclone related risk mitigation works for eligible strata title properties. (Read more here, here, here, here, here, here, here and here).

NSW Floodplain Harvesting Regulations Blocked

The NSW Government's proposed floodplain harvesting regulations have been disallowed in the Upper House.

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The regulations which were blocked in parliament, included the process of determining floodplain harvesting licences, specifying how floodplain harvesting will be measured, and providing an exemption for rainfall runoff into an irrigation tailwater drain in certain locations, during specified times. Christine Peak, a policy manager for NSW Irrigators Council (NSWIC) has argued that the regulations would improve water security for the downstream communities and environment as “Without licensing, there’s no cutback, no accountability, and no safeguards.” Greens MP Cate Faehrmann motioned that they should be review by a select committee to “…give a voice to communities, farmers and First Nations people along the Darling-Baaka River”. (Read more here).

Flood Preparedness and Response Framework

Molino Stewart’s Neil Dufty has published a paper on the findings of the Wimmera Flood Knowledge and Language Social Research project.

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The social research was conducted in six flood-prone communities in the Wimmera region, Victoria, and used a research framework that analysed possible contributing factors to community preparedness and response levels. The research was conducted across all five flood risk categories used by Wimmera Catchment Management Authority. The research provided an insight into issues and possible interventions to manage them. For example, it found that prior flood experience was a major contributing factor to preparedness and response behaviours. However, risk perception did not strongly influence the willingness to evacuate in a flood. Gender and age were also important factors in some behaviours, for example older males were more willing to drive through floodwaters. (Read more here).

DisasterAWARE to Provide Cutting Edge Early Warning System

NASA Disasters Program and the Pacific Disaster Center (PDC) have collaborated to produce new flood monitoring and early warning technology called DisasterAWARE which is available in Australia.

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DisasterAWARE uses a model-of-models approach and underlying flood risk data to produce maps which combine flood severity and likelihood. The system was recently used by Geoscience Australia on behalf of Emergency Management Australia during the March 2021 floods to make more informed disaster response decisions by quickly understanding flood severity and extent. (Read more here).

Vegetation Mediates Long-Term Hydro-Climatic Phenomenon

A long-term climatic study by researchers at Flinders University, SA, have revealed insight into the causes of Australia’s strong climate variability.

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The study unveiled a vegetation-mediated seesaw wetting-drying phenomenon between eastern and western Australia. The phenomenon is characterised by eastern Australia gaining water, while western Australia is losing water, and vice-versa being reset by strong La Niña induced continent-wide wetting. The research suggests that this is dependent on vegetation cover prior to a strong La Niña event and is explained by subsequent vegetation and soil moisture interactions. Flinders University PhD student Ajiao Chen explains that: “These findings support the idea of better stormwater harvesting and other environmental measures and more disaster risk and adaptive land management in the wake of a strong La Niña induced continent-wide wetting in Australia.” (Read more here).

Explaining Temporal and Spatial Variability of Rainfall in Australia

An article published in the International Journal of Climatology has examined how El Niño-Southern Oscillation (ENSO) and the Interdecadal Pacific Oscillation (IPO) can determine the timing and inter-annual variability of extreme rainfall in Australia.

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The researchers found that there is a clear spatial north-south delineation in the season when extreme rainfall occurs in Australia, as the north had more extreme events in the summer with the opposite occurring in the southern regions. Furthermore, the study found that extreme rainfall in southeast Australia is not strictly related to season and as such is more difficult to predict. Instead, southeast Australia shows the greatest shift in seasonality of extremes in response to large-scale variability such as IPO and ENSO phases. (Read more here).

Queensland’s Economic Assessment Framework of Flood Mitigation Projects

The Queensland Reconstruction Authority has published a framework to undertake economic assessments of flood risk management options.

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The framework has been delivered as an initiative of the Brisbane River Strategic Floodplain Management Plan and was developed through a collaborative process with other state governments, universities, private practitioners and key stakeholders. The methodologies outlined in the framework are used to support economic assessment processes and are underpinned by guiding principles which aim to quantify all the types of damages resulting from floods and compare a wide range of possible options to ensure targeted investment provides the greatest return. (Read more here).

Black Mould Follows Floods

In the aftermath of the March 2021 floods, many flood-affected homeowners on the New South Wales mid-north coast are battling the threat of black mould.

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Many of the worst hit residents were in caravan parks in the Port Macquarie area where black mould has infiltrated damp wall cavities. Volunteers from as far afield as Brisbane have travelled to the area to aid in the recovery effort. Groups such as Samaritan’s Purse have cut the wall sheeting 300 mm above the flood line and carried out sanitisation treatments. Health authorities in the area have advised that black mould should be identified and treated as soon as possible as it can present a serious health issues, particularly to those with allergies, asthma, or other respiratory conditions. (Read more here).

Queensland Water Authorities Have Appealed Against 2011 Class Action

Seqwater and SunWater have appealed the decision which found that their engineers failed to abide by the dams’ flood mitigation manual during the 2011 floods.

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The two authorities have argued that it was “far-fetched and fanciful” to believe that engineers could have foreseen the Brisbane floods and made water releases to relieve the deluge. The appeal has been announced following the class action decision (FM February 2021) which saw over $440 million in compensation set to be paid out by SunWater and the Queensland government. The 2019 court decision found that between 39-51% of the flow in parts of the Brisbane River at the height of the flood was due to releases from the Wivenhoe Dam. However, barrister Jeremy Stoljar, acting for Seqwater in the appeal, stated that the risk of reducing the water levels in the dam did not constitute a foreseeable risk to downstream residents. Furthermore, in reference to following dam operating manuals he stated that: “the manual is there to guide and assist decision-making by the flood engineers” but “Much is left to the judgment of the individual engineer who happens to be on duty and for the senior flood engineer.” (Read more here).

FMA Conference Wrap-Up

The 2021 conference marked the 60th anniversary of Floodplain Management Australia and was held online in light of the continuing COVID-19 pandemic.

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The theme of the event this year was “Essential Knowledge for a Flood Resilient Future” and focused on the latest developments and achievements in flood and emergency management to assist in identifying, planning for, and managing flood risks and building disaster resilient communities. Presentations were held over three days from Wednesday 26 to Friday 28 May 2021. Attendees heard from 86 speakers with 67 presentations to choose from. The conference began with a face-to-face pre-conference dinner in Sydney and Brisbane, and for the first time this year there was also a Young Floodplain Manager (YFM) Social Evening held in Brisbane and Sydney while the Melbourne YFM group had their event postponed due to COVID-19 restrictions. The winner of the FMA NRMA Insurance Flood Risk Management Project of the Year was NSW State Emergency Service (NSWSES) and Infrastructure NSW for the Hawkesbury Nepean Valley Community Resilience Program, with Central Coast Council highly commended for Davistown and Empire Bay Climate Change Adaptation Landform Design. The Allan Ezzy Flood Risk Manager of the Year was awarded to Graeme Milligan of QRA, and Paul Grech of GLN Planning. The winner of the Young Floodplain Manager of the Year was Tim Morrison of Catchment Simulation Solutions.

Antarctic Ice Sheet Melting Faster than Originally Forecast

New research published in Science Advances has shown that sea-level rise calculated from Antarctic ice sheet melt could be 30% greater than originally forecast.

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The researchers have calculated the effect of the water-expulsion mechanism which occurs when the solid bedrock the West Antarctic Ice Sheet sits on rebounds upward as the ice melts and the total weight of the ice sheet decreases. The results show that predicted global sea-level rise estimates could be amplified by an additional metre within the next 1,000 years. Furthermore, the researchers explain that the water-expulsion mechanism will mean that sea-level rise will not stop when the ice stops melting, and that the effect on global coastlines could continue for centuries. (Read more here).

Sea-level Rise Placing Coastal Airports at Risk from Flooding

Researchers from the University of Newcastle, UK, have found that under a changed climate almost 600 airports around the world would be at risk of flooding by the end of the century.

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The researchers undertook a global analysis of flood risk to airports in terms of expected annual disruption to routes. The method combined globally available data of airport location, flight routes, extreme water levels, standards of flood protection and scenarios of sea level rise. The results showed that airports presented with the highest risk were located in southeast and east Asia and that by 2100 between 10% and 20% of all routes were at risk of disruption. (Read more here).

Combining News Media and AI to Identify Flood Affected Buildings

Researchers from Tohoku University, Japan, have created a machine learning model that uses news media photos to identify flooded buildings accurately within 24 hours of the disaster.

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Flood data can be collected from previous events; however, the reliability may be reduced on account of event variability tied to the local characteristics of the flooded area. Thus, onsite information has higher reliability. News crews and media teams are often the first on the scene of a disaster and broadcast images in real time of flood affected buildings and infrastructure. This study identified press photos and geolocated them based on landmarks, then used synthetic aperture radar (SAR) PALSAR-2 images provided by the Japan Aerospace Exploration Agency to discretise flooded and non-flooded conditions of unknown areas. The model resulted in an 80% estimation accuracy and could be utilised to speed up and increase the accuracy of damage mapping activities. (Read more here).

Implication of Flood Risk Perceptions on Management Foresight

A study published in the Journal of Climate Risk Management has found that flood risk perceptions should be included in climate risk management strategies.

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The paper used the case study area of Wainfleet All Saints in Lincolnshire County, England, which experienced unprecedented floods in June 2019. The researchers interviewed respondents from the Wainfleet flood affected community and professional floodplain managers to explore their opinions, perceptions, feelings, ideas, experiences and recommendations on flood and climate risks. The results showed that both study groups believed that flood risk was increasing in the region and would be exacerbated by climate change. Furthermore, the community had a low perception of their own responsibility and were critical of the Environmental Agency’s negligence of structural flood defences such as embankments. The study highlights the importance of creating policies and practical measures that would enhance community participation and involvement in mitigating their own risks. (Read more here).

Blue Rooves Reduce Flooding

Blue rooves may reduce flood damage to buildings by providing a slow-release mechanism for accumulated rainwater in built up areas.

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Hard surfaces are impervious to rainwater and as such there is often large amounts of run-off in urban areas and the risk of flash flooding is increased substantially. A blue roof system stores rainwater and slowly releases it using flow-control devices or structures, from customized trays to existing building risers that cause water to dam up. The benefit of blue rooves go beyond reducing flooding as the collected water has a cooling effect through evaporation and the water stored can be utilised to water gardens and green roof infrastructure. (Read more here).

International Floods

There were 27 international floods reported across 26 countries in May 2021. At least 120 people died and more than 250,000 were displaced.

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Internationally significant floods included:

Yemen

Heavy rainfall caused widespread flooding and damage in several governorates across the Yemen with at least 13 fatalities recorded and over 3,500 families affected. Heavy rainfall of up to 66 mm at Al Mahwit in the 24 hours to 29 April 2021 was recorded as hundreds of homes were destroyed and numerous people were trapped in the rubble of collapsed buildings. (Read here).

Afghanistan and Tajikistan

Heavy rainfall in northern Afghanistan and neighbouring Tajikistan triggered flooding and landslides. At least 14 people died in Tajikistan and 37 people in Afghanistan as flooding damaged hundreds of homes displacing 700 families, destroying roads, killing livestock and destroying roads and bridges. (Read here and here).

Iran

At least 10 people died and several are still missing as widespread flooding affected 14 provinces across Iran. Emergency services responded to almost 2,000 callouts including 37 rescues from vehicles trapped by floodwaters. Homes, crops and livestock were damaged in Gonabad, and Khorasan Razavi provinces, and power and water supplies were cut off in parts of Kerman Province. (Read here).

Tanzania

Tropical Cyclone Jobo formed over the south-western Indian Ocean around 20 April 2021 and made landfall on 24 April in areas of south of Pwani and Dar es Salaam regions, Tanzania. Heavy rainfall, damaging winds, and flash flooding were reported in eight regions with over 30,000 people affected and 22 fatalities recorded. (Read here).

Ethiopia

Heavy rainfall and flooding in three regions of the country displaced approximately 70,000 people as of 13 May 2021. At least 16 people died across the country and vast areas of crops have been destroyed. (Read here).

India

At least 23 people died in wild weather brought by Tropical Cyclone Tauktae which made landfall in Gujarat on India’s west coast on 17 May 2021. Nearly 200 homes were completely destroyed with almost 7,000 damaged. The Santacruz weather station in Mumbai recorded 230 mm in 24 hours to 18 May. (Read here).

Diary

FLOODrisk 2020 European Conference on Flood Risk Management
Where: Budapest, Hungary
When: 21 to 25 June 2021
For more information visit here

46th Annual Natural Hazards Research and Applications Workshop
Where: Natural Hazards Center at the University of Colorado Boulder
When: 11 to 14 July 2021
For more information visit here

Eighth International Conference on Flood Management
Where: The University of Iowa, USA
When: 9 to 11 August 2021
For more information visit here

Australian Disaster Resilience Conference 2021
Where: International Convention Centre, Sydney, NSW
When: 18 to 19 August 2021
For more information visit here

Flood Expo
Where: Birmingham, UK
When: 22 to 23 September 2021
For more information visit here

Resources

Hydrogeomorphic Floodplain Maps vs. Flood Hazard Maps

Researchers from Uppsala University in Sweden have compared hydrologically-derived and topographically-based floodplain maps in terms of identifying flood prone areas. The results showed that hydrogeomorphic based maps provided higher-resolution constructions of flood-prone zones, but that this method was not as accurate in regions that were dry, steep, very flat or near the coast. (Read here)

Flood Risk Reduction in the Context of the Sendai Framework

A literature review of 40 articles published since 2016 has shown that community-based approaches complement traditional methods and contribute to flood risk communication and perception. The author compared case studies which utilised the Sendai Framework for disaster risk reduction which advocates for people centred approaches to disaster risks. The results showed that approaches involving communities in flood monitoring can, beyond facilitating flood documentation, unlock additional risk reduction benefits such as enhancing social capital and facilitating risk communication. (Read here)

Factors Influencing Flood Preparedness in Small and Medium Businesses

Researchers undertook an interviewer-assisted survey of small and medium enterprises in Malaysia to provide insights into the various factors affecting flood preparedness. The results revealed that risk perception was the most consistent factor in influencing preparedness actions followed by prior flood experience and gender. (Read here)

Good Practice Guide for Dam Safety Released

A guide to hydrological risks associated with dam safety management has been published by the World Bank. The guide is intended to raise awareness and inform specific studies and investigations, as appropriate, during project preparation and implementation for dam projects. The publication seeks to stress that overtopping failures are not a singular risk and aims to assist dam operators in mitigating flood risks in the design phase. (Read here)