Need help with waterlogged orchard

I was shown an orchard today that is on a sloping hillside and it was a real shock! One of the main issues usually with orchards is in getting water and keeping it for the plants.
This place was the exact opposite! The surface was very wet, even gley in some places I would think, with rock and clay under the topsoil. The owners had dug 3 trenches angled across the orchard to drain the water and it showed water flowing quite quickly through the drains, although not very deep. Some of the trees in the wettest areas are dying due to the wet conditions. Existing trees include apples, pears, peaches, plums, a few nuts, and a variety of citrus.

My initial thoughts are to remove all the grass as this is inhibiting to the trees, but also may be contributing to the gleying of the top surface. When it rains the water will run straight down the hill and not be absorbed. I plan to do some guilds as well, but based on the wet conditions I am wondering if people have suggestions a bit different to the normal? Has anyone else come across areas like this and dealt with them using permaculture principles? My thoughts are to use water loving plants when designing the guilds including daylillies, daffodil, voilets, etc. It is coming on Winter here so there will be frosts to account for as well, although in warmer weather I may through in others such as kang kong for mulch as well. There are plenty of acacia nearby which I will use for mulching, but I am not sure if building bulk over the wet areas will actually help or simply make a larger anaerobic layer.

I am open to suggestions as to how you would approach this issue. Note that this is not a wetland at all, the topsoil is only 5-6 inches in most places, the rest is clay/rock mix. The climate I would class as warm temperate ranging from warm to hot summers and frosty winters. Thanks in advance for all your help.

it is understandable why you would be confused, is this an usually high rainfall situation? Is it near urban property where there could be broken water pipes? Has there been flooding uphill?I would be very very cautious of adding more drainage IF it is only a temporary situation that won't be repeated, as it is a slope..and not a wetland. I would try to look uphill to find the problem, maybe there is a spring that has to be routed??

I would investigage the source before doing anything else.

Hi Brenda,
Thanks for your reply although I am almost disappointed you didn't respond with "oh, I know that situation, you fix it like this!"

Interestingly enough, I tried to explain it to some other friends I talked with and I used a spring analogy. Although there was quite a lot of rain here in the first few months of the year, it has not been that wet the last month or so, in fact, we have had nice warm to hot days. If the situation was localised I would be more suspicious of the springs, but since this is a similar situation across the whole acreage, I suspect it is something more inherent in the structure of the soil. The only issue with that is it does not explain where the water is coming from currently? It is almost like the water table starts at the highest point of the property?

I don't want to dig more drains at this stage and I am certainly not rushing in to that, but I will check conditions again in 2 weeks and see what the water level is again. The vege garden they have done using raised beds because the top soil is anaerobic and this is around half a mile away from the orchard.

Thanks again for your suggestions and hope to hear more ideas!

If you have access to a Yeoman's plow, you might try sub-soiling the plot to see if that helps let the water sink in.

Yeoman's plows are often utilized to help 'capture' water in the soil. But if you have a hardpan that holds the water, the plow could help the water to get below the hardpan.

Hi John,
Thanks for your thoughts. If the water was only on the top, that is what I would be doing as well, but the trenches I mentioned are up to 2 feet deep and it shows the soil totally wet all the way through. I would suspect a hard pan being an issue if it was more localised, but this is not in a small area, but it appears to be the case over much of the acreage?!? It is almost like the water table is going completely (or almost) to the highest points on the property and the water soaks out, "springs" etc from almost every point??

If I had land that was that wet, and stayed wet, I'd be thinking of setting up a willow nursery (or other water-loving plant).

our property, although not on a slope, has a very very high water table..what we did was to dig a pond in the lowest point of the closer area to drain the water away, and then we put some cross french drains to a ditch that we dug to go to the swamp in the back to drain the excess water off that was too much for the pond...the pond also overflows into the ditch.

This drained the property well enough to be able to grow trees, shrubs and plants over most of the property and still holds a LOT of water in the soil (mostly clay).

IF it was my land and it was a permanent not temporary situation, I would be digging ponds in any depression that I could find (if i had the $ and equipment)..as Sepp Holtzer says, if you do it in the depressions, naturally low wet areas, then you probably won't require a permit as you are only "maintaining the low wet areas"..

use the excess soil from the ponds to raise some of the areas above grade as well..make sure your ponds are in the LOWEST areas so you don't cause landslides..and make sure there are areas where they can overflow "naturally" from one to another if possible..

let us know how this turns out for you

Jonathan,
I think your idea to plant water loving plants is a good one.
And this is mostly why:
http://www.greenhousebed.com/Permaculture/permaculture_examples.htm
I looked up horseradish and its smaller cousin, wasabi, thinking that they might be good companions for my baby sour cherry. Surprise, both plants love wet, whereas cherries do not. (Though sour cherries are more tolerant of wet than sweet cherries, and actually prefer a bit more water.) My guess is that the cherry was a bit waterlogged, and the horseradish siphoned off the extra water that was bothering it+gave it an immune boost.
Good luck with your orchard.

P.S.: There are some trees with roots known for breaking up hardpan to some degree, you might look into some of those and see if its feasible to interplant a few as a canopy layer, breaking ground for your fruit trees.
There are also quite a few shrub layer and herb layer plants that have a rep for breaking up hardpan. These would likely be more suited to your purposes than a canopy layer, but I thought I'd mention both.