A rather lively - and brand spankin' new - spring... Just where it isn't wanted.

[Adrian]

Thanks, Brian!

[Nightjar]

I don't think there is any doubt that it will be effective. It is a basic principle of land drainage that, on sloping ground, a drain dries the land below it. Whether the holes will show you anything will rather depend upon the exact route the water takes. However, you are going to have to dig a trench for the drain anyway, so digging a couple of holes first won't do any harm.

I would hire a mini-digger, so as not to be tempted to skimp on digging the trench. It is something you only want to have to do once. This goes into great detail about how to do the job:

Colin Bignell

[Adrian]

Unfortunately, access is appalling. There's a couple of steps to the narrow and very badly paved walkway which goes past a couple of neighbours, then a tight 90deg bend part under the bungalow's eaves - and the path involved is under trees, and right next to the heating oil tank.

[newshound]

+1

As long as your trench goes deep enough to intercept the water path. Might be worth hiring a powered auger to do the test holes first?

[Tim Lamb]

Hand digging in wet clay is easy. I defer to Phil's expertise but *springing* here (Herts.) occurs where chalk or pervious material, overlying clay has been exposed in a valley.

The springs in my garden have only just stopped running. Last winter was exceptional judging by the height of the water table.

[Scion]

Adrian put finger to keyboard:

Hiab? Or would it have to be craned over the house?

[Adrian]

It would... But, even then, it'd have to be a VERY long-reach crane. It'd have to go pretty much along a row of four bungalows.

[Nightjar]

The alternative is a couple of Polish navvies, which is what BT used when they needed to dig a few hundred yards of trench to my house.

Colin Bignell

[Nightjar]

What about a tree that needs lots of water? A willow or an alder would love such a spot.

Colin Bignell

[Adrian]

Yeh, that's definitely a suggestion I was planning on making...

[John Williamson]

Another place for springs can be along a sand layer between two layers of clay or clay and an impermeable rock. Those are fun, because as soon as you block it *here*, it starts coming out *there*, which can be a foot away or a hundred yards, depending. Sometimes, they just move for the fun of it.

[newshound]

We have some like that in our horse paddock.

[Sam Plusnet]

The OP is dealing with a spring. Your approach would be excellent for surface water, but might not work for a spring. I live on the side of a hill. Rain sinks into the cracks in the bedrock, follows the interstices & then emerges at unpredictable points on the slope where these come near the surface. From time to time the water changes route & the point at which the water comes to the surface shifts for no apparent reason.

Since the water comes out of cracks in the bedrock, it may go nowhere near your land drain at the highest point - certainly true for my garden.

[Nightjar]

He says the ground is clay, which makes me think that surface water is the most likely culprit.

Colin Bignell

[Vir Campestris]

Just so long as it's nowhere near the house.

We've got a report than 15 years before we bought the place they had to take a willow down because it was causing subsidence. 50 yards from the house concerned.

Andy

[The Natural Philosopher]

willow and alder are shallow rooted but will suck hard in clay soils causing heave in dry weather..

fondatins need to be about 750mm to a meter for willow

[Nightjar]

Some years ago, I wanted to build a porch on the side of the house. As it was about 5m from a willow, building control wanted 3m deep mass concrete foundations, which would have cost a lot more than the porch.

Colin Bignell

[Adrian]

[Peter Crosland]

Forget willows and start here

[Adrian]

A total of about 7.5m from the furthest boggy bit to the drain, and a drop - in stages, not evenly (yet) - of 360mm. The ground immediately under the slabs is just clay, and absolutely _sodden_.

Just to make life even more fun, the single-skinned heating oil tank's only about 750mm or so away.