Building on a flood plain!!

[handyandy]

Im currently building my off grid pad on an acre of wet ground having already built and sold a house on adjoining (and even wetter!) land some 10 years ago
Of course if I had the choice I would build on a lovely dry elevated site but I have to work with what I have got
The house I already built has been there 10 years and water has never gotten higher than the level of the driveway (the driveway is pretty much a stoned drain/soakaway)
Still im planning ahead and wondering what flood defences others in a similar position have put in place in a permanent rather than temporary measure
A month ago I got a digger and opened up a fresh ditch to the river (about some 100 metres away) and it seems to be letting the water away to the river quicker
any air venting im installing will be elevated and im planning to use the digger to construct an earth bank around the perimeter or the site
I have checked historic flood plains maps etc and it lies in an 'at risk' area but since the river has been dredged and widened there hasn't been flooding for 10 years

Anyone else in similar position?
advice/ideas appreciated

Id hate my 'Bug In Bungalow' to be a water feature!

[Devonian]

Isolated flood defences (such as those to protect a small number of properties) will only ever work for a short period of time.

If you have a prolonged flood, days rather than hours, then the water will get past your defences.

The only sensible option (if you haven't started the build yet) is to raise the ground floor level as high as you can - have steps up into the house.

Although the area has not flooded in the last 10 years, with current weather patterns and urbanisation, flooding will get worse not better, so even 2 or 3 feet higher (more is better) than the ground level, could make a huge difference.

[handyandy]

Isolated flood defences (such as those to protect a small number of properties) will only ever work for a short period of time.

If you have a prolonged flood, days rather than hours, then the water will get past your defences.

The only sensible option (if you haven't started the build yet) is to raise the ground floor level as high as you can - have steps up into the house.

Although the area has not flooded in the last 10 years, with current weather patterns and urbanisation, flooding will get worse not better, so even 2 or 3 feet higher (more is better) than the ground level, could make a huge difference.

flooding has only lasted a matter of hours in the past but im hoping my newly dug ditch will help
yes ive built floor level 2 courses (blocks) higher than I normally would build.trouble is I can only build floor level so high as planning has restrictions of ridge height
flooding in the past has come from water running down from surrounding fields and this in the past being the'sacrificial' field!
even though the floor level is reasonably high and ive built the footings so that no water should get through im thinking of some sort of
solid path/small wall that will surround the perimeter of the house but blend in rather than looking like some civil works scheme!
the people I sold the last house to have had no problems and aren't too worried but I like to be prepared............hence being on this website!lol

[Slazanger]

What about a queenslander style house ?

[poppypiesdad]

Flood pains well ......

Extream measures build on stilts so the whole property is above the highest , known flood level
Build your house on a large plinth so your above the flood level
Floating house built on a barge that is underground so floats when the water rises

Protection

Put a large rubble/french drain around the perimeter of your property linked to a sump pump /float switch arrangement.

You have said about solid floors so no airbricks are needed
for your woodburner , high level air inlet
External doors make flood panels for them that you can slot in when the water rises
Fit a back flow preventer to soil pipes
Network of ditches to aid the flow of water away .

J

[grenfell]

Perhaps what not to do...
In the Stoke area is a building called Ford Green Hall and it has flooded several times in its history. After one such flood a decision was made to put an earth dam around it which worked ..... until the water got over the dam and of course couldn't get out again. That was in the 80's and I worked there shortly afterwards. There was a tide mark all through the building and I always remember a grandfather type clock completely devoid of varnish up to the water level but intact above.

[Devonian]

Perhaps what not to do...
In the Stoke area is a building called Ford Green Hall and it has flooded several times in its history. After one such flood a decision was made to put an earth dam around it which worked ..... until the water got over the dam and of course couldn't get out again. That was in the 80's and I worked there shortly afterwards. There was a tide mark all through the building and I always remember a grandfather type clock completely devoid of varnish up to the water level but intact above.

My point exactly.

You can normally take action against (slow) moving water, but if you have standing water it inevitably go over, under, around or seep through whatever defence, ditches, drains you have, and there simply is no stopping it.

[handyandy]

lol!good suggestions about types of house to build but ive already the shell of the house built!
if I was to surround property by an earthen/clay dyke (lol!) id most definitely also build a 'sump' to extract any water
within the perimeter.
Simply a hole with a pump in it!
its unlikely that im going to get flooded but id rather do all I can whilst building rather than after ive built
its not all doom and gloom building on wet ground as I have an inlet and outlet so planning to clear out a quarter acre pond
and put some trout in there,also the ground has an abundance of peat which iv been cutting,drying and burning!

[adrian007]

Google Sam Notaro - he has a house on the somerset levels and had his 15 minutes of fame last February

[handyandy]

yeah saw that on news at the time.good example of what can be done if you have the will...............and some heavy earth moving equipment!