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Have you considered a small bridge?
Gorsnak I would assume that if the slope is good enough for a drainage ditch, it would be good enough for a not quite flat backyard.
Digging a hole below the water table and filling it with gravel should cause the ‘moat’ to drain faster than it currently does (you’re givigng the collected water a quicker way to the water table, vs seeping through the soil naturally). However, I don’t think this tactic will help significantly (but also won’t cause a worse situation than you have now). This septic system being installed- what kind is it? Is it a raised system? Where I live a leach field has to be 4’ above the seasonal high water table (3’ using a proprietary system). I think your best bet, if you have the yard space, would be to construct a detention area (pond) so that the water collects where YOU want it.
Thanks for the responses so far, although I think that many of you seem to a) overestimate my financial situation, and b) don’t appreciate the topography and neighborhood (not that you would know the neighborhood anyway).
There is no way a retention or detention pond is happening. I realize that’s the ideal solution, but I don’t have the land or the cash to do it.
A pipe to a catch basin would be a good solution, but my street is 200+ years old (first paved in the 1930s) and doesn’t have catch basins. I’d never be able to get the pipe downhill enough to drain somewhere effective, I’d need a right-of-way or an easement through at least 8 adjoining properties and cross under two streets (including my own). Again, cash and land.
My personal choice is a swale into my neighbor’s yard. The land is overgrown, and already lower than my property. Said property is behind the tree in this photo. You can see the extent of the moat. My piece of land is 190’ wide by 280’ long. The house is 30’ from the street. In that picture, the house is just out of the frame to the left.
Regarding the question of measurements, an hour with a transit and a not-too-understanding wife gave me a pretty good idea of the grade. I was amazed that the rear property line was lower than the house, but it reinforced the size of the depression in the middle of the yard.
The dirt mover I’ve got coming originally suggested regrading the entire yard, bringing in fill to pitch the whole yard back. His estimate was 190 yards of fill, for $14,000. I don’t mind the water that much.
NinetyWt, you’ve hit right on my reasoning - if the water table is so high, there isn’t anywhere for it to go down the chimney drain. My concern is will this chimney drain allow water up, since it now has an easy path to the surface (there is a 3’ clay layer before you hit the sandy/gravelly glacial till that the ground water usually lives in)?
And for those inquiring about bridges and other works, yes, I have thought about it. There was a 2x10 crossing the moat (not shown in the photo, but it was towards the right side by that large shrub) so the dog and I could go for our walks in the woods behind the house. I figured the bridge would look strange by its lonesome the 10 months of the year that there wasn’t any water beneath it.
After roundabouting like this, though, the crux of my question was would water be more likely to come up this drain than to go down it, given the high water table that my part of the world has during rainy weeks?
Absolutely. You don’t need my two engineering degrees to tell you that, you know it intstinctively. I’ve been thinking about this. You really can’t push that water to your back neighbors; there’s ordinances about that. What you could do is change the location. Grade the lot so that the ponding area is farther back in your yard; that way your dog will have more room. Plant some flowering wetlands type flowers, and enjoy the view. Work with nature, instead of against it.
I agree, the chimney drain carries the risk of water coming back up. Maybe not so great a quantity as you are worried about, but yes if the hydraulic potential pushes it up it will be there.
$14,000 for 190 yards of fill? That’s highway robbery. The best road fill here is $10 a yard. “throw-away” dirt is $5 to $7 a yard. Get another quote.
I think your first step it to find out if this moat is groundwater fed or from surface runoff. If there is a way you could siphon or pump out the water you can see if it refills on it’s own (no rain), or you may be able to dig down to that level on another place in your yard and see if you hit water.
Cool how you linked those picts together 
Dig a ditch, lay some tarp and go for a coy pond?
Liek NinetyWt suggested, you may get some grief (either when you do it or years down the road) if you force the water to a neighbours property. Check with your town hall regarding bylaws for altering the grading and water flow of residential areas. While you are there, inquire about the town responsibilities regarding drainage and ground water maintenance. There may be something they can do…or throw up their hands and turn their back on you…but at least you asked.
I had seen a monster home which had been built in the middle of a block of existing homes. The only piece of land that wasn’t someone elses private property was the driveway. They had to build an enormous detention pond that looked like a giant sand trap filled with 4"-6" rocks. It took up about a 1/4 acre, which wasn’t a problem for them as they were on a 4 or 5 acre property.
If you’ve only got 3 feet of clay through which to dig, then you can easily do your own test. Just dig a small hole - you could borrow or hire an auger - and fill it with non-clay soil and see what happens.
Sorry to bump an older thread NinetyWt ducks from mods it occurs to me that the thicket of your neighbor’s might be impeding the water flow.
What did you find out, if anything?
This weekend I took a trip into the pricker bush that is the back section of my neighbor’s yard. I found four things:
- Her yard slopes to the marsh behind both of our yards, and with some “selective” clearing, it looks like water in her yard will go into said marsh.
- My yard definately slopes towards her yard, and the water has somewhere to go if an old drainage trench (for lack of a better term) is cleaned out.
- Hi, Opal
- There is a bit of poison ivy mixed in with those pricker bushes (you can guess how I found about about that).
Either way, the chimney drain won’t be happening. I just have this vision of an eternal spring popping up in the yard. Man’s triumph over nature continues.
It now appears that I’m going to do my elderly neighbor a favor and restore the ancient drainage system, then undo the favor by sloping my moat towards her yard. No one will ever know - bwahhaha!
Unless Mass DEP reads this board…