Below is a fairly typical description of Yamba and environs during high rainfall and flooding events.
Even though it appears text and images have been produced between 2015-2021 it seems to be considered by the NSW Government as a contemporary description rather than an historical one.
Read it carefully if you live in Yamba or have been a holidaymaker in the town when the Lower Clarence River has been in flood in recent years.
NSW State Emergency Services (SES), Flood Awareness NSW, retrieved 13 September 2022:
Clarence Valley LGA
Yamba and Palmers Island – Are you at risk?
Yes you are!
Yamba is located on the southern bank of the mouth of the Clarence River. The main impact of floods in the area is isolation, however several residents and commercial properties can be inundated in severe floods. Even in minor floods, Yamba may become isolated when Yamba Road closes. Another consideration during local floods is the influx of tourists during holidays and summer season, who may be unaware of the local effects of flooding.
Palmers Islands is located directly west of Yamba on the southern bank of the Clarence River. Most of the land on the island is prone to flooding. In a minor flood, Palmers Island becomes isolated and surrounded by flood water. In a major flood some properties may experience over-floor flooding and some residents may need to evacuate.
Rural land along the Clarence River around Wooloweyah Lagoon can also be inundated and substantial numbers of rural properties can become isolated.
The period of isolation for these areas can vary depending on the size and duration of the flood, as well as high tides preventing drainage to the sea. Any residents wanting to leave the area would need to do so before flooding causes Yamba Road to close.
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| Palmers Island Yamba Road Store and School Flooding |
Do those five short paragraphs and that one image match your experience of floodwater and stormwater inundation in Yamba over the last 30 years?
Is it still mostly the inconvenience of isolation that the Yamba community suffers? Is it an accurate description to say that only “several residents and commercial properties can be inundated in severe floods”?
Is anyone else in Yamba asking themselves why that first paragraph quoted here is still accepted uncritically by state authorities, when the lived experience is that the inundation situation has been gradually becoming more pronounced over decades. That the amount of water entering town commercial and residential precincts is long past just nuisance value.
The natural flood storage areas and flood ways within the town, which carry water overland to the river estuary and out to sea, no longer function. In large measure due to the degree of draining, infilling and building over of these these features which has occurred over time and the fact that: (i) the town’s stormwater system can no longer adequately cope with the amount of rain falling from the sky and subsequent rainwater runoff from sloping ground/hard surfaces; and (ii) the river water arriving as flood carried down from higher up the river system whose swirl through town streets is often exacerbated by a tidal pull.
There are residents whose homes have been inundated at floor level in both 2021 and 2022 and residential lots which experienced stormwater/floodwater intrusion onto the property for the first time or at a deeper level that previous flood periods according to homeowners.
A better description of the changing Yamba experience of flooding can be found in an Inside Local Government article of 26 May 2022:
Clarence Valley Mayor, Ian Tiley, has demanded the Clarence be included in any 2022 flood studies and assessments, saying the region had been ignored in initial assessments by the NSW Department of Planning and Environment.
Mayor Tiley put forward a Minute at the June Council meeting following advice from the Department of Planning and Environment that post flood data behaviour assessments already undertaken had focused on the Richmond, Wilson, Brunswick and Tweed rivers – local government areas to the north of the Clarence Valley.
“The flood level at Grafton was not a predictor for the flood behaviour downstream,” the Mayor said.
“It is clear the Clarence flood increased in volume as it moved downstream and staff consider it likely the extreme localised rainfall events in the tributaries of the lower catchment impacted Clarence River levels downstream of Grafton, and that post flood data behaviour assessments may inform these assumptions.”
CVC previously reported in April that Yamba experienced its biggest rainfall event on record, with 1267mm in February and March. This included 274.4mm on 28 February – the highest 24-hour February total on record – and 258.2mm on 1 March for a total of 532mm.
“There has been no event or combination of events since records began that comes close to the rainfall totals recorded at Yamba in February and March,” Clarence Valley Council Director Works and Civil, Jamie Fleeting said at the time.
Getty Images has a collection of photographs which clearly demonstrate the growing dissonance between what is written by government agencies about flood behaviour and the lived experience of the Yamba community in March 2022.
YAMBA, AUSTRALIA - MARCH 02: An aerial view of a flooded street and properties in the town of Yamba, in northern New South Wales, on March 1-2, 2022 in Yamba, Australia.
(Photo by Elise Hassey/Getty Images)
Note: Hover mouse over upper righthand corner of images to reveal "Share" and "Full Screen" buttons.
Yamba's only flood evacuation route in early March 2022.... pic.twitter.com/9FLn2VY1A7
— no_filter_Yamba (@no_filter_Yamba) September 13, 2022
BACKGROUND
Australian Bureau of Meteorology, Special Climate Statement 76 – Extreme rainfall and flooding in south-eastern Queensland and eastern New South Wales, 25 May 2022, excerpt:
Summary
Extreme multi-day rainfall and significant flooding affected south-eastern Queensland and eastern New South Wales from 22 February to 9 March 2022. The heavy rainfall began in south-east Queensland and north-east New South Wales during the last week of February, and continued further south into eastern New South Wales in March (Figure 1).
Multi-day rainfall records were broken across south-eastern Queensland and north-east New South Wales, with multiple sites recording over 1 metre of rainfall (Figure 2). For the last week of February, rainfalls across parts of the region were at least 2.5 times the February average (based on the 1961–1990 period), with some parts more than 5 times the average. For north-east New South Wales and large areas of south-eastern Queensland, this was the wettest week since at least 1900. The intense and sustained rainfall across the region led to flash flooding and riverine flooding extending from Maryborough in Queensland to Grafton in New South Wales. Some areas of south-eastern Queensland, such as the Mary River at Gympie, recorded their highest flood peaks since 1893.
Widespread major riverine flooding also occurred in the Sunshine Coast region, and in the Brisbane, Logan and Albert River catchments. In parts of north-east New South Wales, peak flood levels broke previous observed records (reliable since at least 1974 and for some locations dating back more than 100 years) by considerable margins. Devastating flooding occurred through Lismore (Wilsons River) and other nearby towns, including Coraki and Woodburn (Richmond River) and Murwillumbah and Tumbulgum (Tweed River).
In the first week of March, the rainfall system shifted south along the New South Wales coast, bringing further heavy rainfall to eastern parts of the state (Figure 3). As a result, the Hawkesbury-Nepean catchment recorded its wettest 9-day period on record (since 1900) to 9 March (Table 11). With rain falling on already saturated soils and swollen rivers, flood levels in the Hawkesbury-Nepean river system exceeded those reached in March 2021 and were comparable to those of 1978 (Table 12).
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