Buying a house - flooding risk info.

[chris French]

Ok, not DIY, but it's the sort of thing some people here will have knowledge about. given the increasing in flooding we've seen, and predictions for increased frequency in the future, this seems to be something to take seriously. Esp. as I suspect it's something insurance co.'s now have a 'thing' about.

There is a good possibility that we may be moving from Leeds to the Cambridge/Huntingdon area this year, depending on how SWMBO's new job hunting goes.

We've been on the web of course having a look at potential houses, now of course being where it is, quite a lot of those are on the Fens (We are looking for a country property). On the face of it potentially, an area prone to flooding, however, in the recent floods, it's somewhere that I remember having a lot of problems, presumably, because of the nature of the place, the drainage etc. systems are already in place to deal with it -to an extent anyway.

so I've been trying to find some info on this, but haven't found much really helpful.

The environment agency does have maps with flooding risks, but the current ones take no account of flood defences etc., so of course the fens are all coloured blue as a flood risk, not very helpful.

anyone have knowledge of this, or can point me to source of info?

[nightjar]

One of the insurance companies (I think Norwich Union) has done a much more detailed anaylsis of flood risk. They hope to get an edge on the competition by offereing lower premiums to houses where local conditions reduce the risk. They may be able to help. Even just getting a quote from them might be a good indication of the risk.

The other way is to look yourself for any small rises in the ground that might indicate a reduced risk. You may be able to find that from spot heights on a large scale OS map of the area. Also old churches tend to be built on ground that is more likely to remain dry in the worst winters, so buying next to the village church may well reduce the risk of flooding, although it greatly increases your risk of wanting to strangle bell-ringers.

However, if I had to live in the flat, uninteresting and wind-swept part of the country, I would probably follow the example of one farmer and build a large embankment around my house and garden.

Colin Bignell

[Ian Stirling]

Has anyone tried building a house on a raft? Say a meter of polystyrene in a steel structure, with the house on top.

[Anna Kettle]

NFU Mutual are the insurers you will probably end up with cos they know about the countryside, do not panic at sight of the environment agency map and put up their premiums to scare you off. I'd speak to them about any houses you are interested in.

I would think that (in general) the Fens is well prepared for water, with good flood defences in place. The places which have suffered from recent flooding problems have been those where acres of farmland have been covered in concrete

And as a rule of thumb, the oldest houses will be built on the prime spots so now is the time to buy an ancient hovel with lots of DIY potential and there are lots of them out in the Fens

Anna

~~ Anna Kettle, Suffolk, England |""""| ~ Plaster conservation and lime plaster repair / ^^ \ // Freehand modelling in lime: overmantels, pargeting etc |____|

01359 230642

[Christian McArdle]

I believe the Dutch have started doing that, complete with articulated utility services and so forth.

Christian.

[Ben Blaukopf]

If you want to know about specific locations, you could do worse than ask on cam.misc

Ben

[Dave S]

I can confirm what Colin said, it is Norwich Union who have the database on flood risk. It's not exactly in the public domain but they are making it available to the research community. To that end, they gave a presentation on it at my University recently, although I was unable to attend myself. A colleague did, however, so when he's back from the States next week I'll find out from him how detailed their database is. Generally the fens are close to or below sea level anyway, and the water table is lowered by artificial drainage. One problem that can occur, is that at high tide, the sluice gates may have to be kept closed to prevent sea water getting into the rivers. River levels can then back up and cause flooding problems usptream. This happened to my parents house in Suffolk a couple of times during exeptionally high spring tides. Aforementioned colleague has more experience in hydrology than I - I'll check with him next week on sources of information.

[Terry]

World's oceans rising at , what is it? ("Thames Barrier rumoured not high enough?") A metre per century or something; although that may be accelerating due to global warming? Various glaciers from Greenland to Antarctica are receding and iced over areas of various mountain ranges are becoming bare. This had led to 'discoveries' of the "Ice man" (10,000 years?) in Europe, an ancient mastodon in Russia and uncovered artefacts of native hunters from

8,000 years ago in northern Canada etc. Seems that we've melted back somewhere between 5,000 and 10,000 years so far! No matter! Your choice, whatever it is, should be good for say 50 years? Personally I'd 'never' buy a house in an area subject to flooding. Terry. PS. Have an inflatable boat stored high up just in case and some means of getting out through the roof.

[Martin Wiseman]

Hi,

Actually, I think you will find that the fens are all coloured blue because they really do have a >=1% risk of flooding in any given year (the EA's criteria). The big problem with the maps is that they don't tell you how far above the 1% any given area is.

1% is an average of once per century, although I've heard somewhere recently that we could start getting the once a century floods about once every 20 years due to global warming, etc., etc.

I think the last time there was really serious widespread flooding with multiple rivers bursting their banks in multiple places was 1947 - try looking that up for an idea of what can happen. The floods in recent years have generally been restricted to a few known trouble spots.

There are plenty of places between Cambridge and Huntingdon which don't appear in blue on the EA's map, perhaps you should start looking there. Alternatively, try asking again here once you have narrowed your area down a bit more, "the fens" covers quite a big area..

Martin.

[Peter Taylor]

chris French wrote

Chris, try this website. It's a cut down version of the prog the professionals use. You just type in your postcode and it tells you all the info you might need. Could be a bit frightening though! Good luck.

[nightjar]

for a property that I know has suffered floods, for one that used to have floods until a new pumping station was built 20 years ago and for one that has never flooded in recorded history.

Colin Bignell

[Peter Taylor]

"nightjar .uk.com>"

Yeah, that's what I meant by frightening. I'm on the side of hill like a ski jump and the soil is chalk which soaks up water, so we hardly ever see any surface water, let alone flooding, but my friend's house 4 houses down the road gets a "minor risk" level! Also I heard of a woman who was buying a house locally and used this website to discover that the Radon level here is Medium and that 1% -3% of homes in this area are above the Radon "Action Level". That's quite low compared to some areas, but she got it in her head this place is dangerous and chickened out. It would be interesting to hear what Radon levels other people get.

Peter

[chris French]

In message , nightjar writes

Certainly getting insurance quotes was going to be one of the things if we get to that point.

I'm sure it could be a 'feature' :-)

[chris French]

In message , Anna Kettle writes

Buying a house that needs a lot of work this time round probably isn't an realistic option at the moment.

We have a 3 year old, another sprog on the way in Nov. (a move would be likely in early autumn), my wife would be doing a very busy job (her first hospital Consultant post ), mega diy is something I want to avoid.

[chris French]

In message , Ben Blaukopf writes

Thanks I should have thought of that, I've subscribed now. :-)

[chris French]

In message , Dave S writes

Thanks David.

[chris French]

In message , Martin Wiseman writes

OIndded, the info just isn't there yet it seems.

Oh sure, it's just that we've just been doing a bit of looking at what sorts of places there are around out our price range and it happens that we came up with a few places that all happened to be out in the Fens (as well as some in other areas more 'inland'. I appreciate that there are plenty of other areas, and that not all of the fenland is as prone to flooding as some other parts, hence wanting to get an idea of what the risk is.

[chris French]

In message , Peter Taylor writes

TBH, I didn't find it particularly useful - I can probably work out form a map if a house is within 250 of a floodplain - which is what it seems to tell you. Hmm, somewhere with the address of 'White Fen' is surprisingly :-)

I've got a grip on what the current sort of risk is I guess - ISTM that the Fens in general are probably less of a risk than say an old house near a river, or a new house on a floodplain, where there just aren't the defences. what I've really been pondering is what turn things might take in the future.

Anyway thanks for the comments everyone, progress towards a job has taken many twists and turns , so I'm just waiting to see how it all pans out.

Indeed, as in hardly any :-)

Well that was silly, she needs to learn to understand a simple statistic :-)

We are in a

[Anna Kettle]

What a pity but yes you do seem to have plenty on your plate at the moment

anyway it is much better to go to a place and live there and get to know it before buying a hovel. I found a lovely hovel that way and so did a Welsh friend of mine :-)

Anna

~~ Anna Kettle, Suffolk, England |""""| ~ Plaster conservation and lime plaster repair / ^^ \ // Freehand modelling in lime: overmantels, pargeting etc |____|

01359 230642

[Dave S]

Well it seems the Norwich Union database is not quite as sophisticated as it initially sounded. It seems they have a high resolution digital elevation model, onto which they have mapped the position of properties where flood claims have been made. The elevation of these properties gives the elevation 'at risk of flooding' and by combining the two they get the areas at risk of flooding. If your house is in one of those areas they don't touch you and if not, they do.

So essentially it's a very broadbrush approach which is unlikely to pick out the effects of topographic features or defences which would protect individual properties. In principle, this would be possible if combined with good hydrological data, but would be involved and expensive to do for the whole country.

Local knowledge is probably your best bet - local newspapers can be a good source of information on previous flooding. Local residents can also be useful, be be aware that they are very prone to exageration!!

Although I lived near Ely for 6 months, I'm not particularly familiar with the Fens. Since it is so low lying and largely artificially drained, the potential for flooding has always been high. I suspect that it is therefore better protected and the flood risk better managed than in many other parts of the country.

Conversely, in many parts of the country, flood risk has been greatly increased in recent years by changing land use (particularly agricultural land), urbanisation, very poor river and catchment management and to some extent by climate factors. Here, the flood risk is very poorly managed and no-one seems to have a clue how to deal with it, other than the pursuit of misguided hard engineering approaches which have to a large extent caused the problem in the first place.

Not that I'm bitter and twisted about having a proposal for research funding to work in this area turned down, of course....!!!

cheers David