Category: Floods

1 August 2024

Vermont Flooding

30th July, 2024. Around 8 inches of rain fell in 5 hours in the Northeast Kingdom (Essex, Orleans, and Caledonia counties), causing major infrastructure damage with homes carried away by the flood. The 24 hour state record for Vermont remains 9.92 inches (252mm) from a 1999 event. Observer data from St Johnsbury cited 4.99 inches in 1 day as the local record from 1913. Data from the National Weather Service shows totals of 7.81 inches (198mm) in 5 hours, 4.38 inches (111mm) in 2 hours. Multiple media sites suggest this event correlates to a 1:1000 annual chance (unverified). Significant rain and floods had occurred in the area earlier in July from Hurricane Beryl resulting in greater runoff.

31 July 2024

Typhoon Gaemi

July 29th, 2024. Multiple locations in Kaohsiung City County, Taiwan received over 1300mm rainfall in 24 hours during Typhoon Gaemi with event totals of around 1900mm over 3 days.

17 July 2024

Intense Rainfall for Toronto

16th July, 2024. Environment Canada confirm over 4 inches, (100mm) fell in the City in about 2.5 hours during the morning of Tuesday 16th, making it the 5th wettest day at Pearson Airport. Intensities of 30mm in 30 minutes were observed in the city, caused by training thunderstorms. This followed storms on the afternoon of 15th. The Don Valley area saw the greatest impact, largely related to road flooding. The Don Valley had a significant population living close to the watercourse until Hurricane Hazel in 1954, after which the homes were expropriated and land used for an expressway and parkland.

Don Valley Parkway. 16th July, 2024 (Source Globe and Mail)

16 July 2024

UK Farming Output Fell in 2023

July 16th, 2024. Income from farming in England reduced by 19% year on year following the wettest 18 month period since 1836, according to data from the UK Govt and UK Met office. Farming contribution to the UK economy reduced by 8.7% to 1 billion GBP. The cause was part price collapse, and part poor yields caused by the extended wet weather.

6 July 2024

Wisconsin Dam Failure

July 5th, 2024. Five and a half Inches (140mm) of rain fell over the Manawa City Mill Pond, a gated small dam in Waupaca County, WI. The speed of the event saw the right abutment overtopped that subsequently failed through erosion. Unofficial data from Manawa shows rainfall of 4.12 inches (105mm) in 1 hour with 1.69 inches (43 mm) in 20 minutes, and 1.1 inches in 10 minutes within an event total of 5.5 inches (140mm). The timeline provided at the post event public meeting by the City of Manawa advises the gate openings were set on forecast rain of around 1.25 inches, that morning. The dam operator was back on site by 11am and witnessed the dam overtopping. The embankment failed completely around 1pm. Impacts included flooded homes and impacts to the functioning of the wastewater treatment plant. Manawa City has around 1400 inhabitants. The impoundment was 192 acres (0.77km2) with a max depth of 12 feet (3.65 metres).

3 July 2024

Switzerland – Rhone River Records

June 30th, 2024. The Rhone River exceeded peak height records at multiple locations above Lake Geneva, in Valais Canton. The peak discharge at Reckingen was 32% greater than any previous rated discharge in 101 years of available record, commencing 1903. Stations at Sion (108 year record) , Branson (83 year record) and Brig (59 year record) also exceeded previous record flood peaks.

25 June 2024

Minnesota Partial Dam Failure

June 25th, 2024. Southern Minnesota. Rapidan Dam partially failed with water eroding the left abutment during a flood event . The dam was built in 1910 for hydroelectricity by impounding the Blue Earth River, but ceased energy production in 2019 following flood damage. Ice damage also occurred in 2020. The 87 ft (26.5 metres) high dam dam has a catchment of 2430 square miles, or 6239 Km2.

23 June 2024

Swiss Flash Floods and Intense Rainfall

June 21st, 2024. Switzerland. Rainfall led to significant flash flood impacts in the Moesa River valley in Switzerland. Official totals show around 100mm of rain within 1 hour around Grono, with unofficial data showing 15mm in five minutes ending at 19:35 at one site. Landslides resulted in fatalities. Part of the A13 road was undermined by erosion. The discharge at Lumino increased from 214m3/s to 594 m3/s in 30 minutes from 19:45, according to Swiss Govt flood warning data. The catchment area to Lumino is 472km2.

21 June 2024

Widespread China Flooding

June 25, 2024. Multiple Chinese provinces have experienced major flood events in the last week. A record flood in Meizhou City led to fatalities. Chinese media estimates the cost in two provinces alone to be of the order of US$650 million.

31 January 2024

Brisbane – 250mm in 90 Minutes

January 30th, 2024. 250mm in 90 minutes was recorded at multiple Bureau flood warning stations in the South Pine River catchment, immediately north of Brisbane, Queensland. A major riverine flash flood event resulted along Four Mile Creek causing significant damage. The day prior had seen a record precipitable water value of 70.8mm at Brisbane Airport according to the Aerological Diagram, sourced form the Bureau of Meteorology. Intense rainfall also impacted the Caboolture River catchment to the north.

30 November 2023

French Floods Re-write Response Plans

30th November 2023. Several catchments in northern France have seen flood peaks exceed the previous record multiple times in a single month. As an example, the Laine River, near Boulogne, exceeded the previous 2012 peak 4 times in November (Record back to 1970). The new maximum discharge of 68m3/s is 20% greater than the 2012 value. The catchment is about 250km2. The associated rain gauge at Wirwignes (62896001, record back to 1988) achieved new records for every duration examined from 1-14 days during November. According to Meteo France, such rain accumulations have only been seen once before in the Pas De Calais. The ongoing disaster meant response plans required revision given the lengthy impact on utilities and services, even for those not directly flooded. €50 Million has been allocated to assist by the French Government, and €11.6 million provided by the EU. The French Public reinsurer estimates the cost of the floods to be €640 Million.

3 August 2023

Beijing Flash Floods

August 3rd, 2023. Beijing Meteorological Observatory. 111.8mm of rain fell in the Fengtai district of Beijing between 10 and 11 am on the 31st July, part of the heaviest rainfall for 140 years in the city, with a total of 603.6mm recorded in the urban area, in Fengtai. 744.8mm was the event maximum within the city limits at Wangjiayuan Reservoir. The previous record rain event total was 609mm from 1891 although it’s unclear at which location this record occurred. The rainfall was caused by Ex-Typhoon Doksuri.

1 March 2022

Enoggera Dam – Unusual Loading

March 1st, 2022. Brisbane. The Enoggera Reservoir peak lake level of 81.39mAHD in February 2022, had a flood loading just shy of 1:10000 Annual Exceedance Probability (AEP) (1:10000 AEP level listed as 81.4mAHD) according to the approved Emergency Action Plan. Rainfall frequency assessments for the catchment indicate the 2022 event was between a 1:200 and 1:500 AEP representing a discrepancy between the flood frequency and rainfall frequency.