Hard avoid tbh.
Whats the change in level? Worth looking at the flood data as some of it is probably done on 5m accuracy surfaces. So 0-5, 5-10 etc but obviously a house at 0mOD is a lot scarier than 4.9mOD.
Yeah that's what I was asking. Flood risk maps are a bit approximate too.
there hasn’t been anything suitable in our chosen location
Is this shorthand for we can't afford what we'd like but this house is cheaper. If so there is your answer.
For me, no, not worth the risk and the 12 months of misery that follow. Even if it doesn't flood if you try to sell it's going to be more and more difficult.
2m DTM with vertical accuracy of 100mm I think,off the top of my head.
I wouldn't. My SiL lives in a gorgeous village near the river Monnow. Flooded in 2019 for the first time in ages - they ended up in a rental for almost a year (lockdown didn't help). A right pain.
That night, they had to carry the kids out, through knee-high river water and sewage in their kitchen. Me, every time it was pissing it down as I went to bed after that, I'd be thinking 'am I going to have wake the kids up at 3am again and get everyone out?' forever after. It would do my head in.
It's nothing like 10m or 5m depth intervals thcaptain I suspect you are looking at horizontal resolution of the outputs. Each pixel of the flood extent represent a depthfor that square.
The question of depth is a good one the mapping is a risk foot print. Bit depths will get deeper and more frequent
Have you tried to get a speculative insurance quote? That might tell you everything you need to know.
Sorry you are absolutely right. Jesus my reading skills are going downhill
Thanks for all the input folks, I think we've pretty much decided it's not for us. We're going to go out and have a look at the lie of the land but I'd be surprised if there's more than 2m vertically between the river at base flow and the house. Some posters were asking where it is so here you go: NH 88703 55266.
Ooof, that’s an absolutely no way location.
At that low-lying location elevation and proximity to the coast, you would also need to consider the impact of rising sea level on coastal flooding (Sea surge). The Scottish Govt, SEPA + others entities have been looking at this for all of the major Firths. Even the Clyde is vulnerable given sea level rise. There are several reports out there.
If you look at the UK MetOffice Climate Projections (UKCP) you can see the sea level rise projections by Time horizon (2030, 2050, 2075 etc) near where you live. It's not uniform across the UK
https://ukclimateprojections-ui.metoffice.gov.uk/products
Look at the Marine Projections
In summary, if sea levels are rising then a significant low level pressure system coming from the right direction could cause a considerable storm surge. Storm Arwen in November was a strange one but nearly produced a surge event. Luckily it didn't but if it was rotated a couple of degrees it would have happened. Similarly Storm Malik in January caused 1+m surge in parts of Denmark. Again this could have been a lot worse.
If there is a River gauge nearby you can see historical flow levels and flood heights etc.
EDIT- this one :
https://www2.sepa.org.uk/waterlevels/default.aspx?sd=t&lc=234218
Data doesn't lie or have rose-tinted glasses. People who say I've lived here for 15 years and it's not flooded are probably correct but what we've seen is not really representative of what can actually happen. They do make good vox-pops in the news when Tracey says "I moved here last week and it's never happened before!"
This is also true for data if the river gauge has only been there 25 years but at least the data is pretty reliable
It's not just the house itself - it's the roads around/to from the house too...if the house stays dry will you actually be able to access it, will you or your friends/family inadvertently drive into floodwater on a dark evening when the vis is poor and it's pixxing down. Every large scale flood event that happens elsewhere in the UK now will also have an effect on anyone wanting to buy that house in the future.
It just isn't worth it unless you have no other options.
As others have stated - previous flood levels in the area are largely irrelevant , and as time goes on will become even more so.
TL:DR. Keep looking, 1 in 200 year flood event could very quickly become 1 in 5 (or 2 a year).
The specifics of this comment are not helpful nor true. A 1-in-200 year event is a statistical representation from a high quality flood model which will have been based on good quality input data and science when it was built. If we start to think about climate conditioned views of risk they are going to be different but the differences between 1 in 200 and 1 in 5 are several orders of magnitude!! This comment is very wide of the mark and is exaggerating/scaremongering .
It is increasingly likely that the level of flooding represented by a 1 in 200 yr event today will have a higher frequency in the future, say more like a 1 in 175yr event in 2040, 1 in 150yr by 2080 etc. etc. The change will occur but it will not be so dramatic as above, the risk will steadily increase.
What will be true is that a 1 in 200yr event in the 2050 climatic conditions will be a much larger flood than today's 1 in 200yr event as the hazard is changing over time, We can build climate conditioned views of the risk but you also have to question the quality of the base model they are built on. If the underlying model is not a good/credible/robust representation of today';s risk then any future model built on that will be very wrong.
The future hasn't happened yet so none of these things are irrefutable but things will get worse and the models will certainly improve.
There must be an anomaly on the SEPA risk map at that location, there is a straight line where the high risk bit just stops.
I think the 1 in 5/10/50/100yr thing is misleading.
There is nothing to say a 1 in 100yr event can’t happen two years in a row. Or even twice in one year.
I think the 1 in 5/10/50/100yr thing is misleading
It's not so much misleading as requiring a bit of knowledge to interpret. Also SEPA don't use that terminology, they say 0.5% yearly chance.
You can get a 1- in-100 today and another next week if you're very unlucky.
It's a statistical distribution of the severity and frequency of the size/intensity of that event in that location.
Plenty of sensible advice. I'll reiterate for me the financial risk of the property becoming very expensive to insure and impossible to sell on would be a red flag generally. Specifically for that particular area, it is way too high risk for me, the houses are basically on the geological flood plain with no defences. The one big event on that river catchment might not happen in the time you own the house, but if it does then I would expect those houses to flood, and for it to be fast flowing and dangerous, not something you want to experience. (And as said, though it is unlikely it is physically possible to have two or more big events within a few years, the labels are just an indication of the magnitude of the event.)
As robola has pointed out "There must be an anomaly on the SEPA risk map at that location, there is a straight line where the high risk bit just stops." The river model will let flow come out of bank on the side that is lowest, so immediately opposite the river flows out to the west, but upstream of the Firhill Bridge the river comes out of bank on the east. There is no physical reason for that water to reenter the river and I suspect when these maps are next updated those houses will be put into the 'high' likelihood (10% per annum) to just below the 10 m contour. There is a field drain next the houses that may not be adequately modelled and might act as a conduit to floodwater from the river. And I think the current flood risk maps don't really take into account 'combined' flood events where rainfall gives river flooding but at the same time the storm winds lead to coastal storm surge and waves that 'back-up' the river and exacerbate flooding. So the true risk to that area is higher than those flood maps suggest and is going to get worse with climate change. Sorry I wouldn't touch it.
FWIW, to get significant coastal flooding/storm surge in that location you'd need a storm that comes from the north which aren't that common (but they do happen)
