Buying a house - flood risk

I would avoid. My parent’s house in Braunton was a mile away from a tiny stream .
Being slightly elevated saved them from those awful floods.
It’s a problem that is going to get unimaginably worse very quickly.

Our house is next to a river but raised up - it had never previously been at flood risk but those 'once in a 100year storms' we had a few years did flood the adjacent area but not near us. Since then we have been included in the flood risk map and insurance premiums have risen.

Just because your near a river doesn't mean you're going to flood. It all depends what is happening up and downstream in terms of flood defence/mitigation.

A moderate risk wouldn't bother me as long as insurance wasn't an issue.

those ‘once in a 100year storms’ we had a few years did flood the adjacent area

This house is in a 0.5% yearly risk area so that's 1 in 200 year event isn't it? Although the prevalence of such events is probably going to change and obviously it doesn't mean it won't happen next year etc.

It all depends what is happening up and downstream in terms of flood defence/mitigation.

These are circumstances that are outside your control and could well change within the timescale of house ownership. As flooding is also becoming more likely with climate change, it'd be too great a risk for me.

Having been flooded out of my house in the big floods in Sheffield in 2007, I personally wouldn’t look at a house that had a ‘realistic’ risk of flood. The key word being realistic, what you think is realistic and your appetite for risk.

The one thing we can pretty much guarantee is flooding in the UK is increasing in frequency and severity, so unless mitigation measures are taken locally or by yourself (flood walls & gates etc), I’d expect your flood risk to increase.

The being flooded wasn’t the bad part (at the end of the day it’s only stuff), but getting the house re-instated was an utter ballache which took 11 months of hassle on a daily basis. The problem is that when you have a flood claim, it’s very likely that lots of other people in the same area do as well. In my case the insurance companies couldn’t cope or find the trades to do the work to the required standard due to the sudden acute demand

Paid through the nose gif flood cover for the next 10 years as well

I work in flooding imho opinion I would totally avoid it.

But if you do buy it and it then does flood please do not start bitching and moaning you have flooded to SEPA.

There are so many variables here it is hard to say. I would be very cautious and as a minimum expect your insurance to be more expensive.

You need to try and understand the bit of the river system it is near and why the SEPA model shows the moderate risk. Is it near a large river in the middle of the main flood plain? If yes avoid. Is it a minor tributary where a quirk of topology means it could back up a bit but probably not that deep, far more nuanced and potentially not that big a concern.

These are circumstances that are outside your control and could well change within the timescale of house ownership. As flooding is also becoming more likely with climate change, it’d be too great a risk for me.

Oh, I totally get this and agree. I work in civil engineering on flood defence schemes for a company that also produces the flood maps insurance and works closley with the EA on flood defence and mapping. I understand the risks. If you can find out what flood mitigation measures have been put in then I might go for it if the house is right. Everyone loves a view right?

If there has been no flood measure for a long time then no I wouldn't go for it.

What bothers me as well is poorly designed surface water systems around houses or houses with no flow paths, driveways that slope down to the house with nowhere for the water to go, apart from a token channel drain across the garage door....

As per Kuco's comments, I work in this field. Wouldn't touch it myself.

To a certain extent it's not even the flooding that's the biggest issue, it's that flooding becomes your life.

Do you want to be constantly watching the long range forecast and soil moisture deficit data? Spending your weekends in school halls discussing potential flood risk reduction schemes that are at the whim of a funding mechanism controlled and led by politicians. I've seen first hand what it does to people, it's the opposite of what I want out of life.

It would be lovely in summer though, and there's the rub.

But if you do buy it and it then does flood please do not start bitching and moaning you have flooded to SEPA.

Now why on earth would I do that?

We moved out of a place that was at moderate risk but had never flooded. What's very pretty over summer can turn into a source of anxiety over heaver rains, which seemed to me to increase during our stay there. I guess I lost my appetite for risk, was mindful of climate changes, and was concerned about who would buy if the proverbial hit the fan. As @ads above says, it may not be direct risk either: there may be water coming from different directions, which has nowhere to go because of the nearby [high] river. There may be solutions, but I'd spend a few quid and find out what they are before I buy.

Don't want it to sound like I'm being flippant about flooding, as I've also seen the devastation it can cause.

If you really want the house, do you homework. Find out everything you can about what flood mitigation and resiliance measures have been put in, or can be put in, or might be put in, in the future.

End of the day though, if you're unsure now, will you ever be happy about it.

It's certainly worth checking the impact in house insurance costs, which are only likely to go in one direction. We're just far enough away from the Spey to fall outside any current risk but I do look at the maps occasionally to see if they are being redrawn.

If you can find out what flood mitigation measures have been put in then I might go for it if the house is right.

As part of my earlier reply I was also thinking of risk increasing schemes. Eg, there was some really bad flooding in our local town, Northwich a couple of years ago. Upstream a huge housing development is being built on the flood plain. The developers were in the local press saying how pleased they were that how the increased ground levels meant all the plots stayed dry, saw it as some kind of vindication that the scheme isn't fundamentally flawed, while 1/2 of the town centre is ****ed.

There were other issues too to compound it, lack of maintenance on a huge sluice, but again budgets and priorities may change things like this over time negatively, and there's nothing property owners could do, hell, you'd not even know about it.

Lots of common sense and professional advice above.

I used to live in a flood risk zone in Chester, but though I was reasonably close to the river, it was on top of a sandstone outcrop it was never (in my lifetime) going to flood. It was lazy mapping.

If there is a realistic chance, and your description doesn't fill me with hope, walk away, for all the reasons indicated above unless (1) it is a fantastic location / building and (2) you see it as a challenge.

Question to the experts, is there anyone the OP can go to for independent location specific advice ?

My village has a local flood group as there are a few specific homes that are at a high risk of flooding. Perhaps there is a similar setup where you're looking who could provide some useful local data.

Question to the experts, is there anyone the OP can go to for independent location specific advice ?

Different areas are different but local authority will have strategic flood risk assesments for areas that would coever wider ranging flooding issues and future potential mitigiation measures, EA/SEPA will probably manage large scale flood defence, just goolging would bring up any local flood defence schemes. Not sure about north of the border but in Engand some places have IDB's (independant drainage boards) that manage local watercourses and drainage systems.

Edit: Also as above local groups will have all the knowledge about who deals with what.

@ads678 - Skipton based?

@ElShalimo - I'm not but my company is. I work out of the Leeds office. Take it you know the company or work there also?

Its less than 200m from the river on flat ground.

It's that bit that would trouble me. Is the house elevated in any way?

We bought a house earlier that was flagged as high risk for surface water but low risk for river flooding despite us being less than 50yds from a known flood plain (it floods nearly every year).

To a certain extent it’s not even the flooding that’s the biggest issue, it’s that flooding becomes your life.

This was, for me, the decided factor in moving. My house flooded twice and would've done so again, and every single time it rained heavily or for a prolonged period it was a source of tension and anguish. I wouldn't buy a house that had a "moderate risk"

Nope - it's only going to get worse.

Personally I'd avoid.

We had a house which was built in 1790, it was elevated up, but next to a flood plain. It had never flooded in it's 200+ years (made of Cob so would have washed away). Found it difficult and expensive to insure, partly because of the 'non brick construction' but also because of the proximity to a flood plain.

Flood plains are only getting bigger these days and there nothing to say  small change up stream in the future wouldn't increase your risk.

Just because your near a river doesn’t mean you’re going to flood. It all depends what is happening up and downstream in terms of flood defence/mitigation.

Mine and by the sounds of it ads colleagues made the sepa flood maps. If it's in the flood risk area it's pretty safe to assume it's going to flood at some point. The maps are built on ground elevations, hydrology it's not a "it's near a river" type situation. I can't remember if it was then reviewed with sfdad in mind (flood defence asset register, basically the only flood defences that are official.)

I'd avoid

Edit: ads wrote that ahaha get on message bro

A moderate risk wouldn’t bother me as long as insurance wasn’t an issue.

& you don't mind the hassle of living with no carpets or ground floor furniture, stinking wet house etc. Can you just imagine being flooded out & thinking, 'oh It's ok, we're insured, we'll be sorted in a couple of days'.
Then you insurance premium goes through the roof & you can't sell the house because It's got history.
I'd avoid it like the plague.

Give us a clue where the hoose is

@ads678 - I know several of your RM colleagues. They're very good at what they do.

My father has recently (3 years ago) moved out of a place that flooded regularly.
The small but fairly steadily flowing stream at the back of the garden is about 2m lower than his garden. And narrow/shallow enough to wade across with normal wellington boots on, 3 large steps, max.
There are two bridges and a culvert within 300m downstream of him.

When there is a bit of heavy rain on the hills above the village, all the rubbish that the utter dick of a farmer dumps near the stream gets washed into the stream, blocks the channels under the bridges and the culvert and backs up 10's of thousands of gallons of water that then flooded my dads house and about a dozen of his neighbours.

He's not even technically on a high flood risk area, think it's like once in 200 years.

The stream overflows (usually) 2 or 3 times a year, he (and a couple of his worst affected neighbours) used to rent a skip twice a year and spend a weekend clearing out the bridges and culvert, so they at least had a fighting chance.
EA fined the farmer 8-10 years ago, they had a couple of years with no flooding. Then he did some work on the fields. (TBH, i think a lot of it is grouse moors up there). And they are back to square one. That's when they decided to sell up and move.

And he also spent thousands adding flood defenses to the property. The "decorative wall" along the edge of the garden has been completely rebuilt and has 2m deep reinforced concrete foundations and is full of rebar and a waterproof membrane. There is also a 1m wall between the garden and the patio which is built in a similar way. A sump and float activated pump under the floor in the cupboard under the stairs. No electrics lower than 1m on any wall, everything below the electrics on the ground floor is tiled for easy cleaning as well. They also have a couple of big dehumidifiers in the attic, ready to go, and a little foot operated jack and blocks of wood ready to lift furniture up off the floor if they go away for the weekend...

I'm amazed they even bought the place.

He now lives about 3 miles away, on the very very top of a very very large hill. Windy as hell, but no flood risk.

TL:DR. Keep looking, 1 in 200 year flood event could very quickly become 1 in 5 (or 2 a year).

Some really good advice and experience on here, but my view is "don't".

The situation won't get better, and the constant nagging worry, cost of insurance and difficulty trying to sell would do my head in. And even if it was your forever home and you stay put, the risk will be increasing as your age means your ability to cope is reducing.

TL:DR. Keep looking, 1 in 200 year flood event could very quickly become 1 in 5 (or 2 a year).

This is it really. When our risk guy did a course he pointed out the apprentice and said you'll see this happen.

I just checked by the way. Those maps probably a little conservative these days but should include any flood defences.

the constant nagging worry

That was when things tipped for us, when it wasn't just a few heavy days in Winter but some super-heavy rainfall at the end of a recent summer. Of course, possibly a one-off, but...

Wouldn't even consider it. There's enough to worry about these days without added threat of a flood every time there's a storm! It's a situation which can never improve either, only get worse. Also what if you needed to sell the house on at some point?

It’s amazing how many people buy houses near water courses and when they flood start moaning to the EA that they have flooded. What looks like a nice little brook in summer can turn into a raging torrent in winter.

In the catchment I work in a couple of years ago the flooding affected us for 6 months. I saw places flood that I never seen flood in 23 years of working in flooding and it’s only getting worse.

My parent’s house in Braunton was a mile away from a tiny stream

We installed the footbridge over the “river Caen “ up near Tesco . As part of the RAMS the guys had to wear life jackets and we had to have an inflatable boat at the ready whilst erecting.
Oh , how we laughed at the ankle deep trickle that was the “river”.
A bit different a decade or so later though

But it does depend on the local situation. What the flood map doesn't tell you is the severity of the flooding. It could be a very low chance of the whole of the downstairs being underwater or a very high chance of your driveway being under 10 cm of water and then once it gets to a certain depth it overspills elsewhere. You really need to use the map in conjunction with studying contour lines etc to understand what the potential is.

I lived in a converted barn with a stone floor that flooded once every 2 years, but only to a depth of <0.5 cm. Basically a tiny stream that ran through. So, based on how long I lived there it had a 50% chance of flooding each year. But a 0% chance of actually getting the furniture wet.

I live in a High Risk area (200m from the Thames). But in the most recent historically high floods of 2014, we were not affected. Also the house is slightly raised Victorian property. Must be location dependent, although insurance is not cheap. I'd be more concerned about a small stream at the end of a garden with some history turning into a torrent than a major river with monitoring and regular flood warnings from the Environment Agency.

It's all been said. As a climate scientist, albeit a relatively sanguine one, I would avoid unless I could convince myself that the 1 in 200 estimate is pessimistic. How high is the house really? A metre or two could make quite a difference. Would you like to say more precisely where it is?

It's not just climate, it's also more houses being built in the area and upstream, increasing the speed of run-off. "Better" (for who?) drainage of farmland.

Some friends living in the river valley here have regular flooding, they have a stone floor, no carpet and a pump set up in a little sump. It's still sometimes bad enough to swamp their electricity supply, I had to rescue their freezer contents once when they were on holiday. They say it was worse before the sewage pipe had a non-return valve fitted...

As a very general rule, I doubt I'd remotely consider a home less than ten metres above water level around the UK.

10m is very conservative. A large part of Ayr is lower than that including my parents' house, it's not a flood risk. We don't get 10m floods. But I would agree it's certainly something to think about in general when buying a house.

Been there and done it. Not a chance I'd buy a house even moderately at risk.

I've recently moved into a house close to a river (Irwell) in a similar flood warning area, 0.5-1% risk, plus a bit of surface water risk.
I guess we are about 10m or less above the river level (steep high bank).

Did cause some thought but went for it anyway based on:
- I've never known the area to get remotely close to flooding in the last 20 years, despite warnings.
- I checked the records (by the way you should do this, you can do a FOI request from the Environment Agency) and the last recorded flood was for 2 days in November, about 150 years ago.
- There has been a new flood catchment area built nearby in the last 10 years or so.
- The insurance didn't care, all they ask is "has it flooded within the last few years" (5 or 10, can't remember)

So. Here we are. Signed up for the flood alert service just in case, but not really worried.
Hope I haven't jinxed it now...

The big question in this is why are we still building homes on known floodplains there are 100s going up near the Calder in Wakefield within a few metres of the normal bank and river level they will flood at some time soon…we are high enough up to not be affected directly but when our surface water has nowhere to go there will be problems I’m sure they will sort it all out at cop27😉

Discounted several houses for this reason.

My neighbour down the bottom of the hill by the burn in the mill cottage - he has tanked all his downstairs and hard surfaces with tiles - raised all electric outlets and cables above the “water line”

His whole house is surrounded by a 6ft tanked wall with the drive way on the high side - to which he has inserts that he seals it off with and sand bags etc.

He loves the house has lived there years and did the majority of the work during the build.

But even he admits it’s a stress if he’s away from home and it rains. It’s all contingent on him getting all his furniture and garage contents to higher parts of the house. The garden wall buys him a lot of time though and has reduced water/house interfaces to allow once in 10 years or so

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.

I think you might have been replying to someone else @joshvegas?

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)