Flood risk - how to evaluate

SophieUK_2

I have my eye on a house that's close to a small brook. On the environment agency website it's shown as being very close to a potential flood risk because of this, so I bought a report from homecheck.co.uk to check things out further.

The report shows that the EA map has the brook flooding in 'extreme' cases, ie: a 1 in 1000 chance, and the house lies outside the predicted flood water anyway.

However, the RMS maps show the house within range of the flood water (only just) from 'pluvial' flooding, eg: surface water, heavy rainfall, although again the brook seems to be the source as the line of pluvial flooding follows the brook exactly. This map says there is a 1 in 75 year risk of this kind of flooding.

So...I'm just trying to evaluate the actual risk of flooding. Does the RMS map, with its 1 in 75 year risk of flooding, mean I would be daft to buy this house? What is being careful and what is being paranoid?!

Incidentally, the house is about six foot about the level of the brook, and about 15 feet away from it, and there's lot of land lower than the house for extra water to flow into without raising the level of the brook (allotment for a starts). To the eye it seems almost impossible that a flood could occur, but maybe it is not just the brook I need to worry about, maybe it is drains etc? How do I know?

The report also gives a rating from Norwich Union saying that the house is at 'negligible' risk of flooding, which would be reassuring if it didn't also say that this was just regarding coastal and river flooding, and not surface water flooding.

Am very confused!

PasturesNew

I'd ask the seller and even door knock the neighbours.
I'd google it too - if it's flooded you can bet your bottom dollar somebody's snapped it and hosted it, or stuck it on youtube.

Strapped

I agree with PN. Try asking in the local pub or post office - they know all And btw - sounds very much like my old house - we never got flooded but I did have a couple of sleepless nights (in 7 years of living there) where I kept popping outside in wellies and a dressing gown, clutching a torch and meeting my neighbours out doing the same thing, peering at the level of the brook which was starting to creep over the top... I don't think I'd want to go through it again.

moonrakerz

SophieUK wrote: »

This map says there is a 1 in 75 year risk of this kind of flooding.

The last flood was 74 years ago and everyone who was there then has died/moved away ................

SophieUK wrote: »

Incidentally, the house is about six foot about the level of the brook, and about 15 feet away from it, and there's lot of land lower than the house for extra water to flow into without raising the level of the brook (allotment for a starts). To the eye it seems almost impossible that a flood could occur, but maybe it is not just the brook I need to worry about, maybe it is drains etc? How do I know?

Lots of houses in Boscastle thought that too ! After all, it drained straight into the sea - no problem there.

Personally, I would be VERY wary - there are a lot of people with houses that will be uninsureable or unsellable before too long !

PasturesNew

I was staying in a B&B about 8 years ago that was flooded from miles away... the river banks burst miles away and it just came across the fields. I was up most of the night watching the water literally creeping closer ... and closer. The B&B was on the corner of a cul-de-sac and my window was about 25 yards from the junction.

Eventually the B&B owner gave the word to evacuate, got to my car wearing Tesco bags on my feet... all looked OK, but on hitting the main road it was a lot deeper than the side road.

I worked with the woman who lived in the first house in the road, just beyond the back garden/car park of the B&B (she'd told me about the B&B when I first went to work in the area), she'd lived in the house about 2 years and that morning the water broke up through her floorboards by about 2".

It's really eerie to watch water slowly creeping along towards you. You end up taking little marker spots, like a stray leaf etc as it's the only way you can really see that it's moving... you think your eyes are deceiving you otherwise and it's getting no worse.

PasturesNew

moonrakerz wrote: »

Lots of houses in Boscastle thought that too ! After all, it drained straight into the sea - no problem there.

This is something people don't think of - water can come UP and get you, or it can get you from above. Look at the whole geography of the land within 3-5 miles, where are the waterways, do two converge?

SophieUK_2

I've lived in the area for ages and never heard of flooding, but as has been said, just because it hasn't flooded in the last 25 years doesn't mean it won't flood the second I move in...the problem is I just don't know what is a sensible 'risk' or non-risk and what is being paranoid. I saw in one article that RMS surveys put 1 in 4 properties at risk of flooding - surely I can't rule out that many properties just because of possible floods? There must be a better way to evaluate the risks...

00ec25

Personal experience re 2 properties
Property 1 is by the Thames and falls into the significant (1 in 75 range). The property was built in 1955. The person 2 doors down lived in their house from 1955 to 2004. Never flooded. I have owned it since 1992. Never flooded. Norwich Union refuse to insure it - remember they were the first big insurance company to suffer huge losses from flooding. All others happily insure it and the premiums are not loaded compared to other properties I know.

we got the evacuate now message from the Enviro Agency flood warning service last(?) year when the Thames was flooding way upstream. Nothing happened. Have already forgotten when exactly – although do remember moving furniture upstairs the next day just in case!

have floods occurred? Yes - the local brook burst its banks. 6 houses were flooded. Those 6 were much older and did not have concrete floors (as previous poster says water rises up inside through the floor) nor was the ground floor raised up (ie you go up 3 steps to enter the house)

Since all the excitement about Thames floods the new build spec in that area means the "ground" floor of new houses is now 2 metres the surface. Your lounge window looks out at over head height of pedestrians and you climb a staircase to get in!

Property 2 40 feet from a brook, it is on the flood map at low risk (1 in 200)
We have owned it since built in 1964. The street flooded once in the early 1970’s when the brook burst its banks. This affected the 3 houses at the bottom of the road and this is why the whole road is on the map, as the map shows the origin of the flood zone to be the precise point the brook burst. The locals sandbagged the brook in the 1970’s and there has never been a problem since but in today’s litigious society it will have to remain on the flood map forever more.

– the clue is they are at the bottom(!) of the cul de sac, visibly downhill from everyone els but the difference in height between top and bottom of the road is no more than 1 foot (30cm) and they were the only ones affected then. No one would be affected now
Insurance is no problem

Conclusion
- Ask the locals.
- Consider details of the house and its age eg: presence of airbricks/suspended wooden floor, height of steps in etc
- Do not give way to paranoia. Consider: Do you like the house itself for itself? Do you like the area? Is this the best house you can afford in that area? Will it be your home or just a place to live?

keith969

It seems quite common for houses to be put at risk of 'pluvial' flooding according to environmental searches. Even mine is, and its on a hill some 100m higher than the nearest river which is more than a mile away!

Hailstorm

I am in a similar situation. I received my survey report this week and it said that the house I am in the process of buying is in an area prone to flooding but the surveyor could not see any evidence that the property had flooded. The present owners have confirmed in writing that there has not been any flooding in the 11 years they have lived there.

The environment agenciy's website does not show the street as at risk of flooding but there are at risk areas within half a mile.

I haven't received my environmental searches yet so I am waiting to see what they say about the risk of flooding. My solicitor has also asked the company they use for searches for a quote for a flood risk assessment.

Welshwoofs

Ask around...

My house is about 1/4 mile from the sea and below sea level. It's in a flood zone according to the environment agency and in fact it did flood in 1991. Now normally that would have put me off, but I did some asking around in the village and it was the first time the village had flooded in over 200 years. It was also a bit of a freak; the sea defences were non-existant and there was a spring tide coupled with a strong on-shore wind. Since then, because the mainline train to Holyhead runs by the sea, enormous sea walls were built. I got in touch with insurers and discovered the premiums were not elevated at all for the property.

I went ahead and purchased after this research and going out to walk the sea walls (which turned out to be about 15ft thick!) and was persuaded that even if the freak weather conditions occurred again, there'd really be very little chance of a flood.