High water table beneath house - sump pumps / any advise?

[skhudy]

Hi,

Our house is a mid terrace. Split level - as in you walk in to the hallway and to the two receptions, and walk down 8 steps to the kitchen (and off that 3 steps to basement). Behind the house (15m) and garden is a stream long since channeled into a culvert.

I suspected a high water table before anyway, recently got an auger to do fence posts and basically thought I'd keep drilling and about 1m down hit clay and the water table.

digging under the kitchen today - underneath the kitchen where there is a .5m craw space to soil (damp), as expected another .5m down was the water table.

To cut a long story short, in the last 3 years a few times when it's been *very* wet, I've seen water trickling into the basement from under the kitchen. I'm waiting on a sump pump which I was going to install under the kitchen to stop the basement ever flooding, also, the kitchen has got a damp feeling about it (humidity from below? btw I've injected the dpc cream thing - not sure it works!)

The basement and kitchen has all the air bricks open so air circulates, thinking I should ask the ajoining neighbour at least to put a sump pump in else I'll be keeping his basement dry too!

Any other suggestions? anyone had experience with this? I'm guessing I shouldn't try to install the pump low, as one it will be running most of the time, and two if I do get the water table lower I'm liable to cause problems with the clay drying and the footings of the rear of the house.

I'm also thinking under the kitchen I should chuck down a load of gravel - more surface area for the dampness to evaporate - make sense or not?

Thanks in advance for any advise

 

[Hugh Jaleak]

Whats the level of the culvert compared with the house, and which was there first? (Culvert or house?) Possible the culverting of the stream has removed the ability of the ground under/around your house to drain naturally into the stream.

 

[skhudy]

The water level in the culvert is i'd guess the same depth as the water table I can see in the hole's I've made. House has been there for ~ 100 years, not sure the culvert, but a mention online says the stream is channeled into the culvert where it enters the park, so ~ 20m away from the house.

Come to think of it, the highest I've seen the stream is about .5m higher, which is around the ground soil level under the kitchen crawl space.

Only 5 houses in a row have been built this way, with the walk down to the kitchen, and a basement, the others the ground floor is one level (so kitchen higher), no basement.

I suppose the other things I could consider would be a couple more air bricks for ventalation, and plant a tree out front and back, any other ideas (apart from moving which my wife says!) appreciated.

n.b I will monitor the water level and the culvert water level - if there is a difference, is it my problem or the environmental agency /defra? and water I pump I can put it in the culvert or rainwater drain?