A recent local newspaper article of 12 October 2022 stated that Clarence Valley Council would not release the results of a circa 2014 floor level survey of an unstated number of Yamba homes.
This survey was apparently undertaken to assess flood risk vulnerability against potential flood height modelling for Yamba township and environs.
The reason Council gave for withholding this information appears to be; “Premature release of the floor level data might (for instance) result in one or more sales falling through without the statutory immunity of Council being assured.”
By Census Night in August 2021 there were 4,073 residential dwellings recorded for a Yamba population of 6,376 people.
It is possible that conservatively between 30% to 53% of this housing stock is vulnerable to varying degrees during heavy rainfall associated with adverse weather events and Lower Clarence River flooding. A smaller percentage of Yamba dwellings above flood height on Pilot Hill and environs may be still be at risk - from land slippage during prolonged heavy rain and high seas.
Now according to propertyvalue.com.au there have been 142 houses sold in Yamba and environs in the last twelve months with a median price of $925,000.
Looking at online real estate sites there are also a number of dwellings in the town currently for sale – ranging from modest houses on manufactured relocatable housing estates through to 3-4 bedroom brick family homes and onto million dollar plus residences of up to 5 bedrooms & 2 bathrooms with all the mod cons.
There’s no easy way to establish floor levels in Yamba just by viewing real estate websites or looking at documents currently publicly available on Council’s own website. The only historic information publicly available ‘guesses’ dwelling floor heights in many of the town’s streets based on the surveyed height of the adjacent road surface.
An estimation method which clearly had its drawbacks in March 2022 when this overview of a section of Yamba Road was taken.
Embed from Getty Images
If Clarence Valley Council is determined to cloak in secrecy a more accurate extant list of floor heights, perhaps it’s time that the Yamba community began to help people who want to move here make informed choices before committing themselves to a mortgage or spending their hard-earned retirement savings?
Remembering that the Lower Clarence River estuary has flooded on average every three years since the 1990s, looking at Google Earth as well as basic digital flood modelling that Clarence Valley Council has available online and, then sampling from the over 50 dwellings currently advertised for sale for an example of each of the three aforementioned housing types:
that sweet little 3 bedroom home in one of Yamba’s manufactured home estates is probably only est. 4m above mean sea level and, if its floor level doesn’t turn out to be at least 2.84m AHD then there is a statistical 1 in 100 chance in any given year that it will have stormwater and/or floodwater running across the bedroom carpeting;
the 4 bedroom brick home with a tidy garden is probably est. 4m above mean sea level but if its floor level isn’t high enough then there is a statistical 1 in 50 chance in any given year that flood water will enter the property and threaten the house. There is also a 1 in 100 chance in any given year that with a floor below or even at 2.84m AHD the river will come knocking at the door and take possession of the house for as many days as it pleases;
when it comes to one of those houses with the million dollar plus price tag, well it is an est. 3-4m above mean sea level. However if its floor level falls short of 2.84m AHD then it may be uncomfortable to live in as there is a statistical 1 in 50 chance in any given year that flood water will enter the property but possibly not the house. However, there is also a 1 in 100 chance in any given year that storm water and/or flood water will enter the property and threaten the ground floor areas of this house.
Needless to say all three example residences are highly likely to be inundated during an extreme flood event given that modelled flood water heights would reach above the ceiling of the average single storey house design and above ceiling level on the ground floor of the average two-story design.
I rather suspect that Council is not voluntarily offering up that information to prospective home buyers, unless they happen to ask a precisely framed question in writing over the signature of their solicitor and perhaps not even then – given how many hundreds of land or house & land packages property developers are hoping to sell over the next five to twenty-five years in Yamba and how attractive future increases in rate income are to local government.
Although quite frankly with Australia’s climate already having warmed on average by 1.44 ± 0.24 °C since national records began in 1910 [Dept. Planning and Environment, AdaptNSW 2022] and the possibility being canvassed that the world and Australia will reach long-term 1.5°C warming as early as the 2030s, Clarence Valley Council has more to worry about than riverine flooding.
In a worst case scenario due to the expected increase in sea-level rise this warming will bring, a significant amount of land within Yamba town precincts will be begin to go under water at high tide in another 8-17 years time.
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| Climate Central Inc. interactive mapping Sea-level rise at 1.5°C global warming Click on image to enlarge |
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