As I said, I think we’re looking at the water table around the house rather than a blocked drainage.
I think I might pop over to Espace Emeraud this afternoon in search of wellies and 50m of 25mm hose - I can connect that to the pump and see if I can clear it temporarily at least.
The problem with it being the water table height, of course, is that there is an infinite amount of water waiting to re-fill the space.
I might recommend going for plastic racking as I have in my damp garage
Oh, I do feel for you! 
Would it be worth visiting the Marie to gently question/complain that the drains may be blocked? Of course, it may well not be a drain issue but wouldn’t cost you anything to try putting the problem in their plate.
I find that our village Marie is quite responsive to pleas. I hope yours is too.
The racking will be OK it’s all powder coated. The shelf - probably, I did paint/seal them thoroughly. If not I’ll just replace the bottom ones. They need raising a couple of inches though, that part of the cellar has never been more than slightly damp .
Thanks 
Let’s face it - much worse could happen.
I feel for you as well, don’t discount the blocked drain idea altogether, we have two farms and both have had problems with basements/caves flooding at some point, in both farms we have substantial man made wells that were for pumping farm water for the field water cannons and cows, both are substantial 12 x 25-35ft wells with
6-8ft of water.
The first basement could flood to 6 inches and like yours we thought it was the water table, but on opening the well up we found that the water table was a lot lower (even mid winter) than we thought it would be, it was the pump drain that had collapsed in both occasions and the water was just recirculating.
The 17th century barn which we thought should be very very damp because there is a 12ft deep moat running alongside it is almost bone dry for some reason even though the moat top level is 8ft up the rear wall.
Certainly at the moment the pump was not doing anything effective.
The drain to look at is almost certainly the one outside the cellar door but it can wait until things dry out a bit.
The ground here seems to saturate very quickly - when I arrived on Saturday there was standing water on the gravel drive, as the soil is fairly sandy that can only happen if it is soaked for some way down. It has drained away now but I think I know where it went.
The adjoining plot almost always floods in the winter (it is empty “for protection of local waterways”) - it’s 30-50cm lower than the lowest point on our plot so that’s why I think the local (possibly very local) water table sits there during wet weather…
We’re on a high ridge between two river valleys so it will sod off somewhere else given time, it’s already 1.5-2cm lower than yesterday.
Fortunately as described earlier in the thread we’d had a hint that no part of the cellar could be reliably considered dry so anything that would not survive damp was moved to the garage - the wood that was in contact with the floor was basically scrap anyway. This has just sealed its fate.
Unsurprisingly (as I think they have a reputation for not being cheap) Espace Emeraude hasn’t got wellies/work boots in my size under 100€, Casto does a cheap 19,90€ pair but (again unsurprising) not in stock in my size (46), so that will have to wait until I get home and can buy a £20 pair from Screwfix.
Sorry if this has been asked before but what is the make up of the cellar floor?
Concrete which I presume is a fairly sandy mix and porous (not all concrete is porous, of course).
Is rhe water clear or muddy?
What is the depth of the sump?
It’s pretty clear. Not that that’s clear from the photo.
Not more than 40-50cm
The walls look to be rendered so even though water is getting in it is probably arriving at specific pionts, often easy to spot.
Possibly, though I’ve seen water seep into the cellar via the walls which it doesn’t seem to have done this time - but beads were forming all along the surface, not specific points. Almost looked more like condensation (but I don’t think it was).
Ok, 18 inches or so.
Again is you have already done this, my apologies but all you need is a sump pump with float that will only activate when sump is full then a very long hose. Curing the ingress of water is best tackled by simply moving it out faster than it arrives.
Clearly is a sump is already there it has been along standing issue and probably a built in feature from initial construction.
My guess is that the beads are condensation as if there was a water build up behind the rendered walls it would blow the render with its pressure.
Sorry for the typos!
Sat in supermarket concourse while wifey perusing the sales. Big fingers, small screen.
You have accepted that the cellar is a damp area, aren’t they all.
So plenty of ventilation and sensible useof the area is best practice.
What is the cellar roof/ground floor construction?
There’s already a pump - currently I think wherever it sends the water is also part of the flood so it’s just been recirculating it, for now I’ve switched it off.
My plan had been to buy some wellies, and some hose and do just as you suggest, then look at a permanent shift of where the pump sends it’s effluent. But I’'ve stalled on the wellies bit (Casto seem to have some larger gauge hose which is not too eye watering for 25m10m - rats, I misread the listing).
Actually I’ve just noticed Jeff’s French cousin (amazon.fr**) will sell me a cheap pair of wellies which should be here Thursday, so just need hose now.
The sump, yes. Some of the “plumbing” appears to be more recent as there’s a clear trench been dug which has been re-concreted over the top.
I’m keeping an open mind - doesn’t behave like condensation and I don’t think the conditions are right for condensation to form on the walls which are likely to be the same temperature as the air in the cellar, but it’s certainly a possibility. I take your point about water under pressure taking the render off though.
Unless tanked, yes - but I’ve no plans to try that.
Indeed.
Concrete beams. Hardwood on top of that.
** Jeff in this case being Jeff Bezos - chez nous we took the Top Gear habit of the Stig having various international cousins and applied it to Amazon - so “Jeff’s French cousin” is Amazon.fr
Lunch at Flunch beckons, will return later!
Yes, the wall surface will be the same or close temperature to the air in the cellar but the earth behind the wall is invariably warmer and more so the deeper it gets. Sweaty walls are natural in cellars for that reason, and of course dry in the summer when rhe temperature balance reverses.
So the trench has been filled in?
Has the cellar floor got a manufactured fall towards the sump? Assuming it has then this woukd indicate that when the house was built it was known that water would form in the cellar.
Are there condensation beads on the underside of the floor/concrete beams or is this surface bone dry?
Once the room above increases in temperature (it will take a while for the floor structure to heat up) then you will get ‘sweat’ beads forming just as they do on the walls.
As already mentioned lotsof ventilation required. Of course this is counter productive to wanting the ground floor to warm and retain heat.
An insulation blanket fitted to the underside of the concrete floor beams would greatly improve house temperatures but of course the underside of the blanket must have a none porous surface.
If the current headroom in the cellar is restricted then this might not be a good idea.
Yes, it’s all neatly level with the floor, but obviously not original.
Not really, or very slight - it does have lower gutters all round though
Oh, most certainly - the gutters would not be there otherwise, but the implication seems to be that the assumption was moisture would soak through the walls (granite with lime mortar).
I’ve never seen any evidence of condensation on the cellar ceiling.
The only time that there has been condensation form on a surface between the air volume of the house and that of the cellar was last visit when the back of the cellar door and the underside of the stairs to the first floor were sopping wet. I commented on it in a post I think - I assume that, although the cellar air was not especially warm it will have had very high RH (it’s always been 80% in the cellar, come what may) and the house will have been colder (it was wheth the outside temp was below freezing and the house was somewhere between 5-7° until we put the heating on.
I’m not clear why - you’d want warm, moist air hitting a cold surface for condensation wouldn’t you?
Probably not practical. Something to think about though.
As I’ve mentioned in a previous post we’ve had the house almost 8 years now (bought Feb 2015) - up until Covid we never had much of a problem with the cellar, humidity was high which did odd things to cardboard down there, and we had some localised water collection (never more than a cm deep) which was sorted when I realised the pump had stopped working and replaced it. Certainly not flooding.
However since Covid it’s been increasingly problematic - no flooding though (or evidence thereof) until this year. All this has corresponded to a definite period of higher than average rainfall, which I’m sure is the underlying reason.
Well, I was just able to go down to the cellar tonight - still a few puddles of water here and there but I can walk on the floor without wellies.
The presence of some marks on the hot water and CH buffer tank, and on the wall on that side adopt new significance. It’s obvious that there must have been a previous flooding of the cellar between our last visit at the beginning of Dec and now - some (buoyant) items simply “moved” with no other explanation - so I’m thinking the line indicates the “high water” mark from last time.
It’s 26cm up the wall. 
I think my priority now is to make sure the pump is effective at emptying the cellar, even if it means just leading a hose out onto the gravel temporarily - our next definite visit is not until Easter, even if we manage one in between it’s likely to only be for a couple of days or “long weekend”.
At least I have turned the lights out
