Swamp thing/you make my heart sing

April 7, 2008 11:55 AM

Home Drainage Filter: What can I do about a corner of my yard that develops standing water for ~36 hours after a good rain?

So far I have lived in my house now for about 2 and a half weeks. In that time there has been a huge amount of rainfall. We received 3 inches just this past Friday! I've noticed that the right corner of my back yard develops some pretty serious standing water and I am utterly clueless as to what to do to remedy it.

There is a marked low spot of unknown origins there, approximately 5'x10'. The water in the low spot is of a depth to cover the (medium-size/mutt) dogs ankles when they stand and play in it. Which they do often. They have also dug at least one huge hole there, thereby increasing the low in the low spot. The water eventually drains/goes away after about 36 hours. I'm not sure if the spot ever really dries out completely as I have not lived here long enough to see 48 consecutive hours of dry weather. The corner is the corner where my yard and my three neighbors' yards meet. None of their yards have standing water in the adjacent corners.

My original thought was to simply plant a rain garden there but I read that a spot that has standing water for more than 24 hours is not good for rain gardens. I'm hoping this is incorrect information because I would dearly love to have a rain garden.

Is it possible to just fill in the low spot with top soil? Do I put gravel down and then dirt? Is a rain garden out of the question? I am desperately (perhaps pointlessly?) worried about the oncoming mosquito season. The water *does* drain eventually. It just takes a day and a half.

This is my very first house so every little thing is freaking me out!
Thanks!

posted by hecho de la basura to home & garden (14 answers total)

I think the usual thing is to install a French drain.
posted by willpie at 12:09 PM on April 7, 2008

Well, mosquitos don't breed in a day and a half. It's really not that big of a concern.

If you're really worried about it, you've really got three choices. First of all, you can plant something that will suck up the water quickly. Depending on your climate, trees like corkscrew willows might be a solution... but you'll still have mud there for at least a day afterwards. Soil just doesn't dry out that quickly!

Second, you could try raising the area using sand. Again, this depends on your climate, and what type of grass you have. This is the solution I'd choose in my area, since St. Augustine grass likes to grow on sand. Two caveats is that you then need to make sure you haven't created another low spot, or just pushed the problems into your neighbors yard... and dogs really really like digging in sand for some reason.

If all else fails, I'd plant an area of garden with some plants that have rapidly spreading root bases and use water quickly, and run a french drain consisting of a pipe with holes drilled into it in a bed of gravel underneath the garden. The pipe must then be trenched DOWNHILL to a drainage area of some sort... either another gravel bed covered by dirt and grass somewhere else in your yard with better drainage, or out into the street, etc. If you can't run it downhill, fughtetabout it, it'll just back up into your garden and then you'll have a floating happy dog puddle with PLANTS. :)
posted by SpecialK at 12:10 PM on April 7, 2008

If you've got room for one, a French drain will handle that mini-bog nicely.

Me, I'd install a carnivorous plant bog, if the low spot got full sun.
posted by jamaro at 12:13 PM on April 7, 2008

It's hard to answer this without seeing a diagram of the topography of the back yard and the surrounding lots, but I'd be looking in terms of adding more soil to force the water to a location that does get adequate drainage. I'd be tempted to bring in a couple of truckloads of topsoil to accomplish this, as gravel beds do have a tendency to get eventually blocked up from inflow of sand and silt.
posted by crapmatic at 12:17 PM on April 7, 2008

We have a couple of catch basin in the low spots of our yard that divert the water to a creek through a series of an underground plastic pipes. We hired a landscaper to do some minor regrading and install everything, to make sure we got the grade right and it would actually flow downhill and away from our house. The supplies, though, are available at your local home-improvement center.
posted by Sweetie Darling at 12:20 PM on April 7, 2008

The slow drainage is likely an issue of soil composition as well as elevation. I don't think a rain garden needs to be excluded. Some plants don't want to stand in water of course, and water standing around for a couple days could breed mosquitoes - your period is a little short for skeeters but it's probably worth taking as a legitimate concern. This article suggests amending the top 6-8" of your topsoil with humus-rich soil to improve drainage. It might be worth digging around a bit (literally) to see what the soil is like there- if it's really dense and clayey you've got a part of your culprit. With a bit of elevation and soil amendment it would probably ideal for a rain garden. If you want to think about other drainage solutions you might investigate regrading and french drains, just to get an idea of how water is managed in a landscape situation. Even if you put in a rain garden you might end up working the grade or putting it a bit of drainage, either to manage excess water or make sure runoff doesn't get diverted to the neighbors' yard.

Don't worry too much. I live on about the lowest lot on my block, and although I don't think I've had water standing a full 36 hours I definitely get a pool back there once in a while (and I've been pondering some of the same solutions as you for a while). It's the sort of thing you can tinker with, take your time working out solutions. You might want to look into temporary fencing when you start staking out and digging up that garden, dogs do love a muddy hole...
posted by nanojath at 12:35 PM on April 7, 2008

We had a sump pump (and french drains) installed to take care of a similar situation, since the low spot is right next to the house and we were worried about water damaging the foundation, or seeping into the walls. I'm not sure how far your low spot is from the street or the house, but the further it is to city sewers then the more expensive it will be (laying pipes to divert the water to the street). Also, diverting water to the street is illegal in some areas (not ours thankfully), so check that beforehand.
posted by Joh at 12:51 PM on April 7, 2008

based on your description of the spot, it was probably intentional. often, in subdivisions that are on really flat land, it's common to put small basins in the far flung corners of lots to provide water retention/detention duties. throwing a pile of dirt on it culd mess it up pretty badly, and cause the water to go somewhere where you really don't want it.

can you see where the water's supposed to go? if you can't, then it's probably not supposed to go anywhere. planting vegetation to absorb the water faster is probably your best option.
posted by lester at 1:19 PM on April 7, 2008

You don't need to worry about mosquitos if it's not even wet for 2 days. This suggests that the water is slowly soaking into the ground, and thereby moistening the soil in your yard and recharging the water table. These are good things--building a drain to run it off into the street and the storm sewer is a bad thing for your neighborhood stream and I strongly discourage people draining their yards for no particular reason.

Not knowing the topology of your yard or the type of soil you have, I think you should be able to install a rain garden in your wet spot, eliminating the standing water. This would likely require digging a hole in your low spot and filling it with a more permeable soil back up to the current soil level. A rain garden is a pretty open concept, and I think you could make it work. If you're successful enough, you could probably even route your gutters there and thereby completely eliminate runoff from your yard.

Or you could just not worry about it and try to keep your dogs out.
posted by hydropsyche at 1:24 PM on April 7, 2008

This suggests that the water is slowly soaking into the ground, and thereby moistening the soil in your yard and recharging the water table. These are good things--building a drain to run it off into the street and the storm sewer is a bad thing for your neighborhood stream and I strongly discourage people draining their yards for no particular reason.

I agree. It is much better for the environment to put the water into the ground than into the storm sewer. You can make the basin bigger or provide more sand underneath if it truly does not drain well. You have had some huge rains so the current performance might not be indicative of average rains. Once things have dried out perhaps you want to perform a percolation test. Happy gardening.
posted by caddis at 3:29 PM on April 7, 2008

Thanks for all the answers so far!

The low spot is in the far right corner/side of the yard, about 50 feet from the house. The lot is flat throughout--except for the low spot that is.

I thought about the french drain but because the spot is bound on each side by my neighbors' yards I have nowhere to direct it, except someplace else in my yard maybe. I definitely absolutely do not want to direct the water to the street to cause more storm water pollution. My city has been having a horrible time with storm water runoff and I have been looking at using rain barrels to do my part in keeping my storm water out of the system! (Along with a rain garden! I'm a little obsessed. I started thinking about this even before I bought my house.)

I am going to dig around and do a soil test and see what the clay content is to see if that's part of the problem. It's a relief to know that it's a situation I can tinker with and solve gradually! Like I said, this is my first house so everything seems like a totally gigantic deal.

I have noticed that numerous songbirds use it as a bath so maybe it's not such a bad thing to have a puddly yard. And tomorrow the forecast is rain for three days!
posted by hecho de la basura at 3:53 PM on April 7, 2008

Just chiming in to say that you shouldn't worry too much about this. Most of my back yard is prone to flood like this -- an area about 30' x 40', several inches deep in the middle, the near edge about 30' from the house. It's the low spot on the block, and acts as a catchbasin for adjacent properties' runoff. Fortunately the topography is such that nothing short of a biblical flood can ever bring the water any closer to the house. It's annoying, but it only seems to make the house's sump pump run a little more frequently. It doesn't seem to bother the grass much.
posted by jon1270 at 4:15 PM on April 7, 2008

I have a friend who does stormwater stuff professionally, so if you are having trouble finding plants, MefiMail me, and I'll ask her. If I were you, I'd try to find a local nursery with knowledgeable staff. They'll be able to recommend good plants and something to do about the clay. Places do sell soil amendments that make clay less clay-y, or you could get some mulch and maybe a little sand and mix it up (this is the hard method), or you can just practice good gardening for a while and the roots will eventually penetrate it (this is the lazy method and you'll want to get plants with a tough root that will dig through for you).
posted by salvia at 6:02 PM on April 7, 2008

I had a similar problem. Added woodchip (under a playset), topsoil and compost over several years, and it's fine now. The problem only ever occurred in Spring, so I didn't worry too much about skeeters.
posted by theora55 at 6:17 PM on April 7, 2008