Let the Drainage begin

To first dig a ditch, one must make a path! The ditch will be running between the roofing sheets and the black plastic, where that puddle is at the moment, that's just where earth was dug out to hold the plastic down, which shows you how high the water-table is here. The pictures looking due east and there's only a 1-1.5m drop over 40m right here.

What is really annoying is if you walk down that path, when you get to the end, which is nearly 20m after where the man is now. There is a 2m drop down to the neighbours DRY field. but every time they have cleared the ditch at the bottom out they've dumped the spoil in a bank along our field edge, effectively creating a damn, add that to silty soil, high rainfall and almost certainly some compaction in here and we get a flooded sponge. It's so soft and wet that no machinery can get down here so everything has to be done by hand. The blue blob is the husband and the black one is the supervisor.. my dog.

On the plus side, the soil is not stoney and grows everything to giant size!

What's the plan, Skandi? Do you have any sketches of the overhead layout you could show us?

And once dug, what are you doing with the ditches? Will you fill with organic matter? Are these to be swales of sorts, to moderate the water level in the soil by infiltration? I was just thinking that as your neighbour's spot is two metres lower than yours, it already has somewhere to go, it just needs perhaps something deeper rooted to give the water a path.

What have you been growing in the space? You noted that the soil was good. I was just thinking that, if the ditch itself doesn't do it all, you could try daikon radishes or mangelwurtzels, some deeply-taprooted veg that you needn't even eat yourself, or even pull from the soil, and it would give the water channels down, probably much nearer your mineral layer.

But I am speculating when I needn't. What do the soil layers look like? How deep is this silty soil of yours, and what's underneath it? As in, is it a clay or compacted layer underneath that's keeping the water in place, or is it the particle size of the silt?

This is exciting, in any event. Thanks for sharing your project. Please keep us updated, and good luck!

-CK

Chris Kott wrote:What's the plan, Skandi? Do you have any sketches of the overhead layout you could show us?

And once dug, what are you doing with the ditches? Will you fill with organic matter? Are these to be swales of sorts, to moderate the water level in the soil by infiltration? I was just thinking that as your neighbour's spot is two metres lower than yours, it already has somewhere to go, it just needs perhaps something deeper rooted to give the water a path.

The ditches will be staying open this year, it's an experiment in a way, we had a contractor come and look at the field which is just over half a hectare the price for getting field drains put in was horrific,  and he wasn't sure it would do anything, so these are trials to see if it will drain. (It has been drained before) Not only is the neighbours land lower but we have ditches on both the down hill sides, so all the water has somewhere to go it just won't get there! I would love to get a mole plough in or even just plough the surface see if that sorted anything, but it's too wet for machinery at the moment

What have you been growing in the space? You noted that the soil was good. I was just thinking that, if the ditch itself doesn't do it all, you could try daikon radishes or mangelwurtzels, some deeply-taprooted veg that you needn't even eat yourself, or even pull from the soil, and it would give the water channels down, probably much nearer your mineral layer.

Nothing in the area you can see in that picture, if I turned the camera round I've been growing veg just up hill to the left of the photo is lots of black plastic, this is meant to be turning into a market garden, what is growing in the area at the moment (under the plastic) is nettles, thistles, various grasses and roasebay.  Where we are going with the ditch it is reeds and willow trees. further to the right and into an area we are not touching this year are more interesting plants, meadowsweet, water avons, various umbelifers, sorrels rowan alder willow etc basically anything that likes to grow in a year round bog.
I've tried daikon three years in a row and they die horribly here, carrots happily get to 10inches in the soil and 2-3 inches across, daikon well something eats them, they hardly get bigger than a pencil and full of tunnels. Funnily just out of shot there are some swedes and various other cabbages.

But I am speculating when I needn't. What do the soil layers look like? How deep is this silty soil of yours, and what's underneath it? As in, is it a clay or compacted layer underneath that's keeping the water in place, or is it the particle size of the silt?

This is exciting, in any event. Thanks for sharing your project. Please keep us updated, and good luck!

-CK

We dug a meter and a half pond last year,  (2m wide 4 long) the soil is pretty homogeneous it looks the same right down to that depth, the only real change was an increase in grey/blue clay nodules. the pond took around 4 days to fill from the surrounding soil, gives a little idea on how fast water moves around here.



Here's the layout of the entire area, pictures N/S as normal the photo above is taken from close to the blue line on the middle red line (confusing huh!) there will be two ditches this year, 10m apart with beds inbetween, I'm going to slightly raise the beds as well to help with the drainage. As to why the water doesn't run away, I'm not sure, as I said earlier the pond did fill just with groundwater so it does move around, at least at depth. I should say that the house sits on the highest point and all the land drops away from there, the wind comes from the West but the entire field area is pretty sheltered by being dwn the hill and behind trees on 3 of 4 sides

Thanks, Skandi.

I like the sound of your plans. Had you considered rice, by the way?

Part of the issue sounds like you might not have enough variation in your particle size. It would help to know how, mineralogically speaking, your soil goes. As in, if you were to amend it eventually, which way and with which missing minerals would you amend it? The reason I ask is because you could get yourself some pebbles of the right kind, preferably in a mix of sizes and roughness, and they would add structure to what sounds like otherwise great soil. This sounds crazy, I know, and you might be able to fix it with coarse mineral grit instead of pebbles or rocks, but the key is that I don't think, from what you're describing about how the water in your soil behaves, that there is enough structure to your soil to allow water or air to pass through it.

That's why the grit. The mineral grit will hold space around it open for air and water to pass. If the particle size of your soil is too small, the spaces available are too tiny to allow the soil to drain, except at a trickle.

I would get Redhawk's opinion, but I think what you need is increased soil structure.

That's interesting about the daikons. Not that I am suggesting them as a crop, but if something there thinks they're candy, you might consider them as a trap or sacrificial crop. And dead daikon in the ground are just tubes of compost.

Very interesting about the carrots. I wonder, do you think the drainage profile will change in an area where your root planting is carrots?

Another thing that occurred to me was alfalfa, or something else with a wickedly long taproot. Do you use anything like that in your area?

-CK

Try diverting all the water that is entering the land similar to what your downhill neighbor is doing.
So build a North to South hugelculture at the top of the land.
You could also try running North-South swales on contour thru out the entire site, each swale could be a "pond" and the dirt from each pond could be dumped on the above it to create a high and dry ground to plant stuff in.

Good points, S Bengi.

You could do a series of these drainage ditches, though design them to hold water, or to flood seasonally, then go the Fukuoka route. When it's drier, seed with clovers and compatible groundcover. When it gets wet, or when you flood it, add fish fingerlings and keep the ditches flooded until you get a yield. You'd still be selecting for water-loving crops in the wet or flooded season, but you'd get fish and fertilizer for your troubles, and still have drier planting areas up top.

But let us know how it goes.

-CK

Can't do rice unfortunately we're heat zone 1-2 so it is not warm enough for it to set seed. otherwise it would be great!

Water enters this area via rain, there is a ditch to the north West and North East which catches and diverts anything coming down the hill, straight into the main drainage ditch which is next to the neighbours. We get around 40inches a year spread fairly evenly over the year but slightly more in July and August.
There isn't a wet and dry season it's just evaporation that makes the summer land dryer than the winter. A ditch here is never dry whether you leave it fully open or close it at the end, there is always water trickling through the drainage ditches round here.
we have a spring bottom left of the map photo,that goes into a large shallow depression that was a pond and then down into the ditch on that side. The basic idea is to have a system of ditches with dryer areas in-between the ditches themselves will always have a small trickle of water going through them slightly more in winter than in summer. The tiny bit of very shallow ditch that has been dug so far seems to be working, certainly it is removing the surface water, the idea was to dig a shallow one spade depth ditch first to remove the surface water and then go and deepen it so it ends up around 60cm-1m deep.

outside the red area we have some nice veg gardens that do not need extra draining, but to give an idea how much rain and how little evaporation we get, I have over the last 3 years had to water four times, and three of them were in May for newly sown seeds! We have a greenhouse where I put my tomatos I put them in the ground and after they get 1ft tall I do not water them the entire summer In the greenhouse!, ground water is so high they can get their roots down into it quite happily.

Well today I was extending the beginnings of the ditch and as the top inch is frozen today I could see what the water was doing better. When you take a couple of spades out, no obvious water runs out of the top 9inches or so (it is pretty saturated) Nothing much comes up from the bottom either, but at that 9 inch depth there's a steady trickle of water coming out of the walls of the ditch, it starts as soon as we make the cut and continues for longer than I have patients to watch it. What's this telling me? Is this showing some impermeable layer just under it?

So Further up the ditch nearly done infact and into the area where I have been and will be growing annuals. well the soil is not as deep here, there's around 14inches of the same dark black soil now that I am out of the saturated area there's masses of worms coming up as well, but I think I have found one of the drainage issues. under this soil is a layer of grey gravely clay. absolutely solid I managed to force the spade in a couple of inches and that was it! Interesting that this wasn't present in another area only a few meters away, or at least wasn't present down to the meter depth we dug there. I don't know how deep this layers is. Geologically we're right on the edge of a glacier deposit and on the edge of a salt uplift, combined with later lake deposits I could be looking at a foot or 40ft. It is interesting that the change from one to the other is very sudden, there's no gravel in the bottom of the soil level and no soil or roots in the clay, everything just stops when it hits it.

I think that layer of impervious clay is underneath the entire area not just the small section that you say at the top.
That layer of clay is what is causing your land to flood with what I would consider to be avg amount of rainfall.

The only difference is that the clay is exposed at the top and at other places it is maybe 2meter deep

S Bengi wrote:I think that layer of impervious clay is underneath the entire area not just the small section that you say at the top.
That layer of clay is what is causing your land to flood with what I would consider to be avg amount of rainfall.

The only difference is that the clay is exposed at the top and at other places it is maybe 2meter deep

It probably is present over the area, but a few meters and I mean a few perhaps 20m away at the same elevation it is not present at least a meter down. it is also not present on the other side down at least two meters (they just put in a new road there so I had a look at the subsoil when they dug) That kind of distribution would make sense for the end of a glacier. It also tells me that there's no point digging a deeper ditch, I'll just have to manage the water on top of it. (unless on further excavation it proves to be a shallow layer.) It is not just my land this entire area of Denmark is soggy, all the fields have at least one seasonal pond. Part of the problem is we are always over 90% humidity and it is very cold in the summer, rarely does it hit 20C so evaporation is extremely limited. But finding a possible cause does help deciding what to do.

I don’t understand why you need to drain anything. This is a golden opportunity. Chinampas are epic. I wish I had a piece of land like yours.

Myron Platte wrote:I don’t understand why you need to drain anything. This is a golden opportunity. Chinampas are epic. I wish I had a piece of land like yours.

It's basically unusable drained. nothing useful will grow on it as the ground is permanently wet it never dries out and therefore it has no oxygen, just dig up a single space and you can smell that. It's unworkable for 9 months of the year. BUT the ditch did work, it drains about 5 meters on either side of it, so a ditch or field drain every 10 meters would make the field usable.
I have however moved since I need a roadside position now I have light sandy soil that is nothing like this at all! (and that field is slowly reverting to nature)

Skandi Rogers wrote:

Myron Platte wrote:I don’t understand why you need to drain anything. This is a golden opportunity. Chinampas are epic. I wish I had a piece of land like yours.

It's basically unusable drained. nothing useful will grow on it as the ground is permanently wet it never dries out and therefore it has no oxygen, just dig up a single space and you can smell that. It's unworkable for 9 months of the year. BUT the ditch did work, it drains about 5 meters on either side of it, so a ditch or field drain every 10 meters would make the field usable.
I have however moved since I need a roadside position now I have light sandy soil that is nothing like this at all! (and that field is slowly reverting to nature)

this is literally what a chinampa is for.

Skandi,

You have polders in Denmark I think. There is probably someone who knows how they are maintained and initiated. When I lived in the Netherlands these were very common and generally used as sheep paddocks. Of note you dont need much fencing, as there is no way the sheep can get out.

I would think the modern way of doing it would be to get a tracked mini-ex, starting where the ground is somewhat firm, and dig down where the canals will be, piling the material where you will drive the mini-ex. you can make fingers of usable soil with canals in between. It would take some practice for sure and could be slow as the material you are putting down will slump if there isnt a bunch of organic matter like reeds in it. then you would definitely want to get some stuff growing on the edges to prevent it from slumping over time. modern Chinapa. Or just start from the low end hand digging a canal and letting it drain over time. Once you have established some drainage it should make it much easier to complete.

Tj Jefferson wrote:You have polders in Denmark I think. There is probably someone who knows how they are maintained and initiated.

A 'polder' is the result of poldering, and poldering means making sea into land. Large parts of The Netherlands have been reclaimed from the see this way, and when it happened elsewhere, usually Dutch engineers were involved.
Making land dryer this way usually means pumping water away, think wind mills, later steam engines, and nowadays they're being driven in multiple ways. Pumping water away to the other side of dykes is a given in The Netherlands, without that large parts of it would just be tidal land, and human habitation would be regularly washed away.
What I'm seeing in Skandi's picture looks like very boggy land. There's a lot of that in northern European countries, also at higher altitude. The picture you're giving seems sound to me though, with the canals where water can easily drain into. With Dutch mills and dykes we would obviously move into fantasy territory, be it a nice fantasy.
However, Skandi, did you say you moved away from this property? Or did you mean you just moved to a different solution?

I moved away from it, I still own the place at the moment but we're not doing anything with it. The reason it is so wet is a suspended water table, there's between 1 and 4ft of bog soil which is a mix of silt and sand, and then under that is impermeable clay. and water flows poorly through the soil so while our ditches do drain they cannot drain much. One thing is for sure.. no matter what the drought you don't have to water that property!

There are indeed polders very close to me here... and they have failed it's a huge area that they tried to reclaim in the late 1800's I drove over it today, it's under a good 3ft of water right now, that will subside by July when cows will be put out on it. and it will be flooded again in September, We have Dutch friends who visit regularly and they are horrified by the general state of the main drainage ditches round here and how flooded the fields generally are.

Yes an excavator would make it quite fast to drain if you used open ditches, it has lovely potential with the spring and all the water, but it would cost a lot to sort it all out. Anyone fancy moving to Denmark?

    It looks like what you have is equivalent to topsoil directly on to of bedrock. Basically the entire field is a spring. That’s so cool! I suggest that you dig a bunch of swales, not to hold water so much as to have some well drained soil, and either  terrace the swales at a 2% grade back and forth or put level sill spillways on alternating sides. If the swales are deep enough, you can grow fish in them. Plant the berm with flood-tolerant stabilizers. This property can be productive past your wildest dreams.