How do I landscape a sloping and flood-susceptible yard?

Question

My wife and I just moved into a house in Arkansas a few months ago and have noticed a few drainage issues with the back yard, it has roughly a 5 to 10 degree slope (east to west) and is fenced in. The soil is fairly hard and seems clay like at the surface. There is also a lack of grass at the moment.

The rain water will pool against the fence on the low side (West) of the yard and takes quite a while to soak into the soil in numerous places. The slope also causes loose silt and dirt to migrate towards the west side of the yard (down sloped side) during heavy rains.

I would like to fix this issue. The first thought is to till the land, fill in the low spots with some top soil, level the land slightly, and plant seed. I'm thinking that will help absorb the water faster. I would like to stray from such ideas as dry wells and re grading the land as I think they would be too costly.

My problems arises from the underground sprinkling system in the yard and some stray wires I found running underneath the cement slab patio to some point in the yard (I presume it is a wire for the underground sprinkler system). I have not followed the wires yet but they are only a few inches below the ground (if that) and are rather small in diameter.

I have read the sprinkler system should be around a foot underground, should I be concerned with that if hand till the lawn with one of those cultivating tools from Lowe's? Possibly using a rototiller? Is there a company or anything out there that can give me an idea where the sprinkler system runs (short of marking the heads and guessing/trial and error) and where these stray wires go to (something like a digger hotline, Arkansas one call only does utility type lines)?

Lastly, how do I prevent the rain from washing the new seed and soil towards the down hill side of the yard?

Answer 1

My thought is that your best strategy is to get some organic matter and a little sand into that dense clay. Organic matter is a sponge; it will readily absorb and then release water. Sand and other aggregate is more like a sieve; it creates spaces in the soil in which water can collect, making the soil itself more absorbent. Both of them will also make the soil softer, allowing grass to sink its roots deeper and thus grow healthier. The carbon compounds and nitrates in the organic matter are natural fertilizer to your lawn as well.

If there's little or no grass in the area, it's not going to hurt much just to till it all up. Sprinkler lines CAN be a concern; your average sprinkler line will be between 6 and 12" beneath the surface; your average rototiller will chew up any heads you hit, and can even grind up the entire line beneath. As was said in the comment, sprinkler lines are relatively cheap; HOWEVER, you'll have to consider whether it's worth it to you to replace any lines you hit (in addition to materials cost, you'll either need to get dirty and wet to actually do the job, or pay a crew to do it for you). Generally you don't want to just chew up PVC or nylon into your topsoil, either.

Most systems I've seen are extremely simple; just find each head and connect the dots. To be absolutely sure since you're digging around anyway, you can dig down to the T-joint under each head and see which way the pipe(s) run. By doing this you'll also see how deeply the line was trenched.

Much more important than sprinkler lines is other utilities. Make sure you know exactly where any buried electrical, gas, CATV and water supply pipes are located on your property. Most relatively new neighborhoods should have one dedicated utility easement that carries all these conduits from central service points through to all the properties. Older developments that were built before the advent of certain modern conveniences, or even newer houses that weren't built as part of a large coherent development project, can have these lines practically anywhere on the property. If you call, they will come out and marke the lines for free. If you hit one and come out to have them fix it, it can cost you hundreds.