Impact: Atmospheric River / Moisture

4 December 2024

Oroville Spillway Failures – February 2017

In February 2017, heavy rainfall in the Feather River basin led to outflows
through Oroville Dam. Spillway slab failure occurred  resulting in erosion and damage. Gated
releases ceased for damage assessments and the lake level was allowed to rise
over the emergency spillway crest, that then also experienced significant
erosion. The scenario resulted in evacuation of large numbers downstream in preparation for a failure
event.

Oroville Dam Spillway FailureDownload

Cyclone Marcia – February 2015

Cyclone Marcia (Marcia) formed on 18th February 2015 and intensified rapidly, crossing the coast near Shoalwater Bay, Qld. as a rare Category 5 cyclone. (USA Cat.4). Marcia remained a category 3 far inland on 20th February and after several hours of heavy rainfall, intensities increased with around 250mm of rain in 3 hours over the western slopes of the Calliope Range (Official report).

Multiple record flood height were observed along Bell, Callide, Grevillea, and Kroombit Creeks. Callide (Gated) and Kroombit Dams both observed floods of record with erosion to the toe of Kroombit Dam with 10000-year levels level observed. Environmental monitoring equipment was damaged with one gauging station and building (Stepanoffs) never located.

There was significant flood impacts to residential areas and infrastructure throughout Callide Valley.

Cyclone_MarciaDownload

21 July 2024

Typhoon Hagibis

Typhoon Hagibis impacted Japan in October 2019 with significant infrastructure damage, flooding and disruption to the hosting of the Rugby World Cup. Hagibis is estimated by EM-DAT to be the 3rd costliest (inflation adjusted) on record in the Pacific region since 1991. The event occurred whilst Japan was hosting the Rugby World Cup and preparing for the Japanese Grand Prix. Significant rainfall resulted with over 922mm (36.2 inches) at Hakone, near Tokyo. 99 fatalities occurred with 73% of those greater than 65 years of age.

HagibisDownload

30 January 2024

Auckland Rainfall Emergency

Generated by convective activity associated with an Atmospheric River, heavy rainfall occurred in Auckland on 27th January 2023. Event totals of over 250mm were widespread with over 40mm in 15 minutes at the peak of the event. Over 1300 homes were flood damaged. Infrastructure impacts included the closure of, and flooding of Auckland Airport terminal. There was limited public information throughout the event which led to significant criticism of politicians and emergency managers. The case-study provides great learnings for compound impacts, risk appetite, process, training, roles and responsibilities ,and planning for unusual, but credible natural hazard events.

Auckland Rainfall EmergencyDownload