New drainage ditch Vs french drain

[Petroldrinker]

Hello all.

I have a six acre field that needs attention. After a two year battle I'm basking in the glory of defeating the rushes... ...for now. However, there is obvious room for improvement with the drainage. The field has a ditch on all four sides. These need maintenance but I don't think that will solve my problems. The field has a notable dish, the low point of which forms a fairly straight line in the form of a shallow valley. Although it's a fairly level pasture the good news is that there is a gradient and the lowest corner has a good drain. This field never really got firm enough for me to drive the digger on without damaging it even in the height of summer, this is how bad the drain layout is.
I'm thinking of digging a new ditch along the line of the shallow valley. It would be about 200 metres long. I have an elderly Ford 550 which would make light work of the dig and keep costs low but I am worried about getting it stuck. Then I would reseed which I was planning to do anyway.
Does anyone have experience of similar exploits? Would I be better with a french drain? I've laid a few that have worked well but nothing like this scale, only around gates and drives. It would cost a lot more.
Any experiences would be appreciated.

Thanks.

 

[Derrick Hughes]

How deep are the ditches ?
The first thing I do right or wrong is to dig test holes to find the source of the water , which usually comes from the higher ground , it's if you can get the ditch deep enough to intercept it

 

[shumungus]

Impossible to advise properly without standing in the field. Get someone who knows what they are doing to stand in the field and advise you. Drainage is expensive and it's better to have the correct plan before you start otherwise you will very easily lose a lot of both your time and money.

 

[tr250]

Get a trencher in and do it properly even if you only put a drain every 40m. Your kids will thank you for it or whoever farms it long after you and me are gone

 

[Petroldrinker]

How deep are the ditches ?
The first thing I do right or wrong is to dig test holes to find the source of the water , which usually comes from the higher ground , it's if you can get the ditch deep enough to intercept it

I am pretty sure it's just retaining its rainfall. There is only one field above me and a very old Devon bank between us with a decent ditch either side. I'll be digging my side out but they are both running and I'm confident that very little is getting through to my problem field.

 

[ladycrofter]

Went to a meeting about rushes a while back. They make a mesh of their roots to trap water and can apparently do this so effectively that they can colonise dry sand. Just saying your ditch may not do anything other than cost you time and money.
Also learned that the seeds live 60+ years, so ploughing just spreads them and instead of having random clumps, you end up with a field full of little rush seedlings. They recommended either spot-spraying clumps if practical, or spraying off completely then slot seeding, but said under no circumstances plough. One poor guy said it's true, they had to spray off a reseed (done after ploughing etc.) because it was saturated with baby rushes.

 

[puppet]

You have digger and a slope. What can go wrong? Just make sure it is deep enough at the outfall and the water runs the right way.

 

[Petroldrinker]

Impossible to advise properly without standing in the field. Get someone who knows what they are doing to stand in the field and advise you. Drainage is expensive and it's better to have the correct plan before you start otherwise you will very easily lose a lot of both your time and money.

I've been working my way through all my local land owners trying to find an opinion I can really trust. But I've not yet really found anyone with lots of experience. I'm a builder mostly, the smallholding doesn't add a lot these days, and I've done site drainage plenty. I just haven't ever tried to drain a field. My neighbour is keen on my new ditch idea but I think he has less experience that me to be honest.

 

[Wombat]

I would just pipe it, pop some 4” twin wall in if you are a bit unsure as it’s forgiving and a bit of gravel on top. I don’t like open drains as they are a pain in the butt for spraying and fertilising for leaving buffer zones etc

 

[Wisconsonian]

Start at the outlet and dig your way up, you won't get the grade wrong if you can see the water. Use the backhoe and front bucket at the same time to get unstuck.

 

[Petroldrinker]

Went to a meeting about rushes a while back. They make a mesh of their roots to trap water and can apparently do this so effectively that they can colonise dry sand. Just saying your ditch may not do anything other than cost you time and money.
Also learned that the seeds live 60+ years, so ploughing just spreads them and instead of having random clumps, you end up with a field full of little rush seedlings. They recommended either spot-spraying clumps if practical, or spraying off completely then slot seeding, but said under no circumstances plough. One poor guy said it's true, they had to spray off a reseed (done after ploughing etc.) because it was saturated with baby rushes.

My rushes were brought under control with topping and weed-wiping. It must have been 80% coverage when I started. My homemade wiper worked amazingly well and used less that half the weedkiller I allowed for. I know the ryzomes will be there for a long time, I'll have to keep on top of them, but the grass is good now.

 

[Petroldrinker]

You have digger and a slope. What can go wrong? Just make sure it is deep enough at the outfall and the water runs the right way.

The water definitely seems to be running down hill
The outlet where it leaves my land is between five and eight foot below the soil.

 

[Petroldrinker]

I would just pipe it, pop some 4” twin wall in if you are a bit unsure as it’s forgiving and a bit of gravel on top. I don’t like open drains as they are a pain in the butt for spraying and fertilising for leaving buffer zones etc

My land has about 18" of nice soil and then white clay. Do the perforated pipes work in this type of ground? I can't imagine anything getting through the clay at all.

 

[tr250]

My land has about 18" of nice soil and then white clay. Do the perforated pipes work in this type of ground? I can't imagine anything getting through the clay at all.

Yes if you lay gravel above them then mole drain into the gravel

 

[Wombat]

My land has about 18" of nice soil and then white clay. Do the perforated pipes work in this type of ground? I can't imagine anything getting through the clay at all.

Yes as that’s my whole farm but less the 18” of nice stuff

 

[Wombat]

these was done in sept and has barely stopped running since early Nov, 4” twinwall as it’s easier to do on my own with 8” of chalk over the top

 

[Petroldrinker]

Yes as that’s my whole farm but less the 18” of nice stuff

It's lovely fertile soil. I get lots of grass. It's just that about a third of that field is a rice paddy right now.

 

[Petroldrinker]

View attachment 1002660

these was done in sept and has barely stopped running since early Nov, 4” twinwall as it’s easier to do on my own with 8” of chalk over the top

Love your work!

 

[Nearly]

4" twinwall perforated pipe with stone backfill and a couple of tonnes of stone at the lowest point of the bowl would suck the water away slowly but surely.
Ditches are ok for the edges of fields but across the middle it wants piping and a bit of stone backfill.
Just over order on stone for your day job.

 

[Dry Rot]

If you put in an open ditch you can always pipe it later. (Clip board warriors permitting).