I've got a water problem that I need to address ASATFGO (...as soon as the fire goes out and we're not evacuated), before the rains arrive and I'd like to gather experienced opinions before I break ground.
The problem: the barn is located in a very shallow bowl and there is a proto-stream that crosses right through the barnyard. This proto-stream isn't actual surface water, but it saturates the ground and with the cows in the barnyard for the winter creates a real problem for the cows and humans. We've got gutters all around the barn and on one side there is a perforated drainage pipe I installed ... not sure if it really does anything but there it is. The 1st winter here and prior to installing the gutters we dug some post holes in the middle of the barn and I hit water at 18-24" - like water that just fills the hole and no amount of bailing will remove.
My observations from other holes are that there is a clay layer 2-3' down, the water soaks in, hits the clay and then just flows along it. On the other side of the barn bowl there is a heavy rain "spring" where the water is forced to the surface.
So I need to intercept that flow of ground water before it hits the barnyard.
I was planning to dig a trench (about 4' deep) with the typical gravel bed wrapped in heavy fabric, perforated drain pipe, and then cover it with dirt and hope that it actually works. For a while. Almost all of the excavated dirt can go back in the trench.
Another option is a swale. This doesn't appeal for a few reasons, but maybe I'm thinking about it wrong. First, the swale needs to be pretty deep to get below the clay layer. Second, this is the side of the barn with vehicle (hay truck) access so I would need some sort of 16' wide bridge/culvert there. Third, I need to move the water across the driveway (and a major electrical line...yay). I'm going to have to trench across the driveway regardless (ponds and such await the water once it gets there), but the swale->culvert interface seems higher maintenance than just starting with a buried pipe. Also a swale takes otherwise relatively flat land and bisects it which isn't necessarily helpful. And because of where the water is, all of the burden I remove can't go back and needs to be moved (a short distance to a big hugel ... but its still a lot of loader trips.
I'd rather have a low-tech swale than a drain pipe system with plastic pipe, plastic wrap, carbon-intensive gravel, etc but I'm concerned about the additions of culverts, etc. Your experiences and advice are appreciated.
All I can say is that I have seen french drains work. I have heard of other options potentially working but have also seen them fail if done improperly. I have never seen french drains fail, as they are straightforward in concept and build. The concept I am talking about is similar to the trench that you are describing.
An old fashioned way of building french drains was done without pipes. It's difficult for me to describe, but basically they would dig diagonally downwards away from the area they wanted to drain and fill that with gravel. So the gravel was shallow at the beginning and then gradually deeper. I saw this work near Battleground, Washington.
When you reach your lowest point, you are open to the greatest change.
The materials used today in French drains [mesh covered slotted pipes] are a vast improvement on the french
drains of the past.
Without having any idea of the dimensions involved I believe the French drain will be the most effective, because you are cutting off the flow where it actually is.
I have done that many times.
BUT it is important the pipe involved is big enough to cater for any flow.
Maybe a couple of pipes or a bigger pipe if possible will overcome that problem.
I would fill the trench almost completely with gravel so it cuts the ground flow at as much as possible
The thought of driving trucks through a 4 foot deep swale which intercepts ground water, sounds like a plan to get bogged everyday.
Your comments almost perfectly reflect my state... but your replies have helped clarify that a swale in a busy area of driveway & barn access is not ideal, and thus a buried drain - despite its shortcomings - is probably the better option.
Of course, labeling a gravel trench as a French Drain gets me thinking... back in Wisconsin the layer of clay was on top of a layer of sand. I have to dig waay down, but my French Drains worked beautifully as the effecitvely just piped the water from the ground to that sand layer which absorbed/distributed the water. It may be that I can just dig a trench leading to a deep hole and not have to cross the driveway and scary electrical line... hmmm. Guess its time to dig a test trench!
p.s. The electrical line ... its the undergroundfeed for the house. So much care required! But its really weird and the power company hates it and insists it can't be done that way ... but 50 years ago it was installed so there it is. The Weirdness is that the meter isn't on the house, its down by the power pole and then there's 300'+ of underground cable. Because the underground portion is AFTER the meter, the utility locators consider it private and won't mark it. Paying for private location is expensive ($150+, which seems stupid expensive) - which I did once so I have a decent enough idea of where NOT to operate the backhoe but I don't have nearly enough knowledge of its location to efficiently dig a trench. The main breakers are now with the meter so I can depower the lines and not cook myself ... but "finding the lines with the backhoe" is a bad idea all around. So avoiding the line altogether is a big bonus!
Sounds like you explained why an off contour swale isn't the right answer to your situation. Also sounds like you figured out what is likely your "best" solution, if you can break through the clay layer to drain water away into deeper ground. I would say you convinced me that a french drain is your better choice ;)
Eliot Mason wrote:Alex - thanks for the link. I have to say normally I wouldn't think I'd find good earth-care solutions at a paving site ... but that is pretty helpful. They key is really getting pipe with half holes.
Yeah I was a bit surprised by the source but I thought the images were a good representation of the cross section