Buying house with ‘high’ flooding risk

firsttimesellerldn

Section62 said:

firsttimesellerldn said:

It's a terraced house in the South-East which suffered some bad river flooding around 20 years ago. The street and house was badly flooded then, but hasn't suffered any flooding since and further flood defenses have been installed. The property doesn't have a basement. It's a period property, ie. built before 2009 so should be eligible for Flood Re cover if necessary. 

Did the Environment Agency or local council construct a proper flood alleviation scheme?

If so, this would have been designed to deal with flooding of a certain 'return period' - e.g. 1 in 100 years.  There's no guarantee that there won't be flooding tomorrow - not least because tomorrow there could be a 1 in 1000 storm event.  But the design return period gives an indication of the level of assurance residents have that they won't experience flooding during their ownership.

If you know that historic flooding was caused by rainfall events of (say) 1 in 5, or 1 in 10, and the flood alleviation scheme was designed for 1 in 100, then (if the engineers got the design right) the same types of event won't cause flooding now.

firsttimesellerldn said:

However we are a bit nervous about whether the flood risk is likely to be considered unacceptable by many lenders when we come to remortgage/sell, even those ours are okay with it. Do we have anything to worry about here? Properties on the street do seem to have sold fairly regularly over the years. 

The other scenario we're concerned about is what would happen if the house DID flood again. What's the potential scenario in terms of remortgaging/selling in that case - what approach do lenders tend to take? 

If the predictions about increased flooding are true, then lenders are going to have to become more accepting of flood risk, otherwise they will get a dwindling share of the market.

There are two scenarios if the house did get flooded again.  The first is if the flood alleviation scheme failed to give the level of protection it should have done. In that case it will be difficult to sell/remortgage until something is done to rectify the flood alleviation so it works as it should.  But on the other hand it will be due to a failure by the EA/government to give the level of protection promised so it is likely that compensation would be paid for any losses.

The second scenario is if the event exceeds the designed level of protection - for example if it was a 1 in 200 flood event and the scheme was designed for 1 in 100.  In that case the lenders and insurers should take the rational approach that there is little we can do to protect against the really extreme events, and there are many properties which aren't thought of as being vulnerable to flooding that would get flooded if a 1 in 200 event happens.

In a sense it is similar to the subsidence issue.  A property with protection from a flood alleviation scheme is the equivalent of a property which has been underpinned. Despite having a historic problem, the property now has a known and managed level of risk. Rationally, an underpinned property poses less risk of subsidence than another property which has foundations of an unknown quality.  Unfortunately, buyers, lenders, and insurers are not always rational in their decision making though, and the same applies to flood risk.

DayDreamerandGeneralWaster said:

The thing is that even if the river defences has been strengthened, there is nothing to be done about ground water. Having experienced it in a workplace, it will come up through the ground, made or not, from the drains too, during significant or prolonged rain events. Bringing the contents of the sewer with it. 

That doesn't sound like groundwater flooding.  True groundwater flooding can be mitigated through management of groundwater levels. E.g. by pumping or by drainage.

DayDreamerandGeneralWaster said:

Twenty years isn't that long ago for the river to have flooded. I suspect with what has happened in Europe over the last day or so people will be a lot more wary of this in future.

As above, it depends on whether a proper flood alleviation scheme was constructed and what the design return period is.

I also doubt the tragic events this week will make much difference to people's perceptions of flood risk. We collectively are quite good at forgetting about flood events, even the ones that cause high numbers of deaths.  E.g. if you mention 'Aberfan' most people will have some idea what you are talking about. But mention 'Lynmouth' and you'll get blank looks from most people who don't have a connection to the area, or those who have studied hydrology.

Thank you to you and everyone else for your replies. 

The house is in the Cliffe area of Lewes where quite a bit of the town has experienced flooding before but where people still seem extremely keen to buy since the bad floods in 2000. 

I think I need to read up more about the flood defences put in since then (if any posters know it well I am all ears!) but also just accept that this is a matter of how much risk we’re willing to take. The house isn’t one we see as our ‘forever’ home (not a concept I really buy into anyway) so I wouldn’t want to be in a position of it being very hard to sell or losing lots of value, but equally it is a lovely house house in a great location bar this and we’d have to be very unlucky to end up in that position.

There is also nothing else on the market which fits our bill right now and hasn’t been for ages so if we don’t go through with the purchase we’ve got other things to worry about! 

Thanks again for all the advice.