New field drainage system.

[clbarclay]

I am going to have some fields drained. What limited drainage is there is defunct. Its clay soil so looking at pipes with prorus fill 20m appart over the whole area and mole between them. I plan on getting a jetter to service drains round the rest of the farm.

The question is, is it worth going for all straight runs that could be easily jetted or going for more complex systems will involve mains, laterals, laterals off laterals which would be more dificult to maintain?

The contractors proposing the more complex systems reckon that a good system won't need jetting. The soils type is clay but not pure with a fair bit of sand and/or silt in places. The fields go around a low hill, so straight runs would likely end up going pretty much straigh down the slope in some places, moles still crossing the fall though.

 

[Andrew1983]

If you can put a meter wide concrete ring as an inspection point, we did this last year, it means a lid in the field but at least we can keep a check on it and jet about 800meters of drain without digging any up.
I can't believe how much ocar has built up already, mix of sand and clay sub soil, will probably jet every 5 years to keep it clear.

 

[Dave6170]

Or be a tight arse and sink a 40gal prop corn barrel in like we did as an inspection pit

 

[Kevtherev]

Depending on type of soil make sure you can jet the system in the future.
A completely new system is best with mains and laterals.
(Herringbone pattern)
Trencher job I'm guessing?

 

[Badshot]

As far as jetting goes single runs are far and away the easiest to jet, but they might not work on some fields, we got gps coordinates with the last lot of drainage showing the junctions.

 

[Kevtherev]

Yes for jetting a straight run to an outfall in a ditch like in the fens is simplest.

 

[RimmerF140]

If installed properly a herringbone system will be fine, and as long as the outlet is kept clear. Of all the jobs we did last year, only 1 was draining straight into the ditch.

There are still Victorian systems in the herringbone style installed in sand that have never been jetted and still work well.

 

[franklin]

If you can put a meter wide concrete ring as an inspection point, we did this last year, it means a lid in the field but at least we can keep a check on it and jet about 800meters of drain without digging any up.
I can't believe how much ocar has built up already, mix of sand and clay sub soil, will probably jet every 5 years to keep it clear. View attachment 134828

Is there any chance I could PM you my email address, and you could send me a higher-resolution picture of your inspection pit? We are farming some land which has been drained in the past, but has several (large) fields which all drain to one outfall - the result being that many drains cross tracks etc, and it is not possible to see where any parts of the system have failed as the outfall is running, yet there are distinct wet areas in fields. I reckon we ought retro-fit some inspection chambers where the fields join each other through hedges and tracks.

 

[clbarclay]

Pits sound nice, if they are along a headland margin. I have had one full quote so far and it would turn a squarish feild into two triangles if I did pits like @Andrew1983 has along its main. That quote does happen to put straight runs through the worst patch. I will wait and see what the others contractors come back with.

I do keep finding old clay drains while ditching, many of which are defunct. Its a job to say whether they filled up due to the ends getting over gown or silted up.

@Badshot, did you specifically have drains with juctions beacuse that land could not be drained with sinle runs or would single runs not have been efficient?

@Kevtherev, principally trenchers. One contractor was talking about trenchless runs, without fill, between runs with porus fill.

 

[Andrew1983]

Is there any chance I could PM you my email address, and you could send me a higher-resolution picture of your inspection pit? We are farming some land which has been drained in the past, but has several (large) fields which all drain to one outfall - the result being that many drains cross tracks etc, and it is not possible to see where any parts of the system have failed as the outfall is running, yet there are distinct wet areas in fields. I reckon we ought retro-fit some inspection chambers where the fields join each other through hedges and tracks.

I can try, it was only a Iphone pic in the first place and I think I picked mid quality for posting on here, will try it on best for you

Our contractor dug out a decent sized hole, put a bed of chip in then set the plastic gulley or inspection chamber/ junction box thing, then lowered a meter deep by meter wide concrete ring on top, if you wanted you could set it bellow ground level and work over it as long as you had a good idea where to find it to jet. I got our blacksmith to make a solid lid so it can be driven over!

As you can see 4 pipes converge, and lead off to the ditch some 150+ meters away.

 

[Hurdle bunter]

Pits sound nice, if they are along a headland margin. I have had one full quote so far and it would turn a squarish feild into two triangles if I did pits like @Andrew1983 has along its main. That quote does happen to put straight runs through the worst patch. I will wait and see what the others contractors come back with.

I do keep finding old clay drains while ditching, many of which are defunct. Its a job to say whether they filled up due to the ends getting over gown or silted up.

@Badshot, did you specifically have drains with juctions beacuse that land could not be drained with sinle runs or would single runs not have been efficient?

@Kevtherev, principally trenchers. One contractor was talking about trenchless runs, without fill, between runs with porus fill.

It's worth having a fettle 20/30 yards back up the run in the field to check that they are in fact blocked all the way not just at the outfall, you may be surprised

 

[Hurdle bunter]

Or be a tight arse and sink a 40gal prop corn barrel in like we did as an inspection pit

Depending how deep it is you might struggle to do much work (jetting/rodding etc) in one of them (perhaps I'm just a fat git )

 

[Ray]

We've done quite a bit of draining, and I'm personally a big believer in laterals out falling directly into ditches if at all possible. These can then be seen which are running, how much, and which may need jetting or attention. That said most of our lateral drains have been into main drains as our ditches won't hold that well and often collapse in the sandy areas.

To know whether jetting may be required in the future will be relevant to soil types and more importantly the amount of fall you have on your drains. If there's little fall and the drains run slowly they're more likely to block and silt up, where as with plenty of fall you get much more force with power to flush through and run clean.

 

[Zetor]

I am going to have some fields drained. What limited drainage is there is defunct. Its clay soil so looking at pipes with prorus fill 20m appart over the whole area and mole between them. I plan on getting a jetter to service drains round the rest of the farm.

The question is, is it worth going for all straight runs that could be easily jetted or going for more complex systems will involve mains, laterals, laterals off laterals which would be more dificult to maintain?

The contractors proposing the more complex systems reckon that a good system won't need jetting. The soils type is clay but not pure with a fair bit of sand and/or silt in places. The fields go around a low hill, so straight runs would likely end up going pretty much straigh down the slope in some places, moles still crossing the fall though.

Your contractor should know best, different parts of the UK require different types of systems.
For example in consistent heavy clay it could take over 100 years to silt up however in sandy or pours soils with a high iron content you could be looking at 5-10 years.
20m is a long way apart ok if you intend laying pipe in between in the future.

 

[Fraserb]

I can try, it was only a Iphone pic in the first place and I think I picked mid quality for posting on here, will try it on best for youView attachment 135640

Our contractor dug out a decent sized hole, put a bed of chip in then set the plastic gulley or inspection chamber/ junction box thing, then lowered a meter deep by meter wide concrete ring on top, if you wanted you could set it bellow ground level and work over it as long as you had a good idea where to find it to jet. I got our blacksmith to make a solid lid so it can be driven over!

As you can see 4 pipes converge, and lead off to the ditch some 150+ meters away.

Ive heard of folk using a metal plate so they can find it with a metal detector

 

[clbarclay]

After much head scratching have decided on going with the quote that seemed the most complicated, but on reflection should do the best job. One field would have been virtually impossible to do in straight runs and the other two would have be awkward to do a ddecent job.

 

[Lincsman]

I can try, it was only a Iphone pic in the first place and I think I picked mid quality for posting on here, will try it on best for youView attachment 135640

Our contractor dug out a decent sized hole, put a bed of chip in then set the plastic gulley or inspection chamber/ junction box thing, then lowered a meter deep by meter wide concrete ring on top, if you wanted you could set it bellow ground level and work over it as long as you had a good idea where to find it to jet. I got our blacksmith to make a solid lid so it can be driven over!

As you can see 4 pipes converge, and lead off to the ditch some 150+ meters away.

What stops the ring sinking when you drive over it?

 

[Andrew1983]

What stops the ring sinking when you drive over it?

It's bedded onto a decent depth of stone.