Drainage Project?

I couldn't find an appropriate forum for posing this question, so I guess I'll start here. There is very little grade on our small property and we inherited a backyard which has a tendency to pond following a heavy rain. We've determined that we should be able to move the water if we raise the grade a couple of inches in part of the yard.

Question: While I understand that the best way to go about this would include tilling topsoil into the existing soil before planting grass seed, I am wondering if I could just borrow from the "layering" methodology (aka "lasagna garden") and simply put down a layer of topsoil directly over the low spots in the turf and then re-seed and mulch it? Has anyone ever tried this with good/bad results? I'm still feeling the financial sting of installing a major hardscaping design last summer, so I'd prefer not to drop a lot of money on hiring the pro's to do the work for me, I'm also feeling somewhat lazy and would like to avoid renting tools, if I can get away with it. Any suggestions?

Your idea of "simply put down a layer of topsoil directly over the low spots in the turf and then re-seed and mulch it" is absolutely the best way. I often wonder why people think that tilling is the best way. When it comes to working in a lawn, often times tilling is the worst thing that you can do. Tilling brings up dormant seeds in the soil and drastically roughens and bumps the surface, such that it takes extensive raking and grading to get smooth again.

Your plan is the way to go. And when you add soil to change the grade, make sure you aren't blocking drainage from another direction....

And you may want to do an internet search for rain garden. I commonly recommend that for areas that don't drain as quickly as we think they should.

A rain garden! What a grand idea. Never knew about them but it makes perfect sense. I Googled rain garden and found some excellent resources. Unfortunately, Phoenix is in the ninth year of drought but if I lived somewhere else I would definitely do this. wrightie, let us know if this will work for you in some way. And thanks joepyeweed.

I am not too lazy so this might be too much, but I prefer a mound and dug out area plan. So when the rain comes it follows the natural drainage to the low and there it is a wetland area. Due to the lower grade and grading to this location the run off will readlily seek the lowland and following dry river rock hardscaping you will not need to haul in much soil. Much of your grading (flat shovel) and hole dug out (wetland) will provide the texture of the site.

Ugh! Drainage! We live in a low lying area and the yard has a slight slope towards the back of the property which also pools during a heavy rain. We have a drainage pit there that flows to another drainage pit with a sump pump that then flows up and out to the street. Despite these measures we often end up with a lot of water that continues to flow down into the neighbors property, and if the street gutters are full and flooded then it is 10 times worse. A rain garden wouldn't work for us because it generally rains only during the Winter and Spring. Summer and Autumn are dry, dry, dry. Next Summer we will probably be ripping out the patio and beds and installing a much, much larger drainage pit. We'll be doing the work ourselves - apparently the pros did the work that is already there! We've been tinkering with the idea of making the gardens in this area into raised beds using bricks and then raising the grade a bit where the drainage pit is. We figure we'll probably end up with a wading pool during heavy rain but hopefully it will be contained to our own property.

Edited to say: Great photo and idea Sofer. If we weren't limited to a yard the size of a postage stamp that's exactly what we would do.

This message was edited Dec 27, 2006 10:30 AM

The thing about a rain garden is that the native wetland type plants recommended for rain gardens, tolerate both excessive moisture AND excessive drought. Wetlands have notoriously variable water levels during different seasons of the year, so if you choose plants that have adapted to those type of conditions, then you have incorporated the drainage condition into the landscape.

Joepye, thanks for confirming what I have been intending to do. I do like the idea of a raingarden, so I will likely apply aspects of one as I continue to design and install my cottage garden. Soferdig, we're actually working toward doing just what you suggested. We've dug a couple of dry wells in our heavy clay soil to improve drainage, but they promptly filled with water thanks to the water table here. We also installed hardscaping at the lowest point to help improve runoff to the street. Now, all that - seemingly - remains to be done is to raise the grade in the low areas to push the water toward the hardscaping and out to the road. Oh, and I'll also need to raise the "raised beds" which have been sinking. Sooo, that is why I'm feeling a bit lazy these days. I just want to resolve the worst of the drainage problem.

Btw, other ways that I've been trying to remedy the problem is by renting a core aerator Spring & Fall and topdressing with plenty of organic material. It all seems to be helping little by little, but we're not there yet. Thanks for your suggestions!

This message was edited Dec 27, 2006 5:44 PM

Here's a picture of the problem site. The photo is taken from the "highest pt." which is on a newly installed patio, nearest the house. In back left corner is the lowest point, with a small paved sitting area. There is a slight dip in the turf which you might not be able to see, but that is where the water ponds following a significant rainstorm.

And another, with water.

Agua, agua.

Here is my low spot. It is roughly 50ft dia after this 2 day rain with already saturated soil. I haven't landscaped this area yet but plan on not really fixing the problem, but just planting appropriate trees, shrubs, and perennials that can handle periodic flooding. The good news is that the soil here is good and actually drains fast as this was dry after 2 days, which is pretty typical. It just happens to be a low spot for about 1 1/2 acres.

What about doing some sort of french drain in that area in the rear left of your photo.

Willis

Edited to say oops I saw that you already tried the french drain idea.

This message was edited Dec 29, 2006 12:33 AM

Wow. A "rain garden" might be just the thing for that area, Willis. I'd be curious to hear what you end up doing and how it works out for you.

I think that next time I'll buy a house that's built on a sloping property...

Actually our Village has a program that will split the cost of the installation of a french drain here since it affects more than one property. That is a pretty tempting offer and already has been approved by the village up to $10K their cost to the point of just needing three estimates from contractors. That is one way I might solve it, but a french drain large enough to accommodate this would be pretty big (guessing around 20 ft diameter) and also then I would have to worry about what types of trees might or might not work with a drain wrapped in filter fabric not too far below the soil level. When I tore down the old garage and built the new one I paid extra for a deeper and higher and much wider footing to prevent any floating, heaving, or sinking of the garage.

The only issue I might have with just planting the area is holding in the mulch when it floods. I think I would just use a raised edge of probably steel which would contain it for the majority of the floods and then rake it out of the grass on those rare occasions it gets washed out. First thing is to get rid of all that junk material on the left side of the picture, many of which are my neighbor's dead or dying poplars and that Siberian Elm (the tree in the middle of the water). The Siberian Elm's removal is not in my wife's plan, but I can't stand that tree. She likes the shade it provides, but that is the only thing that tree has going for it.

I would much rather have a Metasequoia, a weeping bald cypress, a Nyssa Sylvatica, as well as Larix, Picea mariana, & Thuja occidentalis cultivars. Also plenty of shrubs to choose from including dogwoods, winterberry, spicebush, chokeberries, sweetspire, elderberry, and viburnums, and much more as you transition to drier ground. But those lists are more for the tree & shrub forum folk.

Willis

Here is my thought to both of you guys. Dig deep and small diameter and use a sump pump to spray the water excess to the perimeter of your property. Fill it with a river rock feature then you could pump it out and call it irrigation that is timed poorly. that would allow the water to go where it wants too. Oh, you will need a french drain to keep it from comming back to the low spot Wrighty. Too bad you don't have a buffalo jump like this and your drainage problem would end. This is a place I visited today.

Yeah, but Sofer the water wants to go to my low spot unless I pump it pretty far and shoot it off my property. The other thing I thought of, which I could float to the Village, is building a giant cistern in that low spot and install some sort of filtered inlet to it. Sound like a lot of expensive re-bar and concrete, but what the hay, that is what I do for a living. It would also give me plenty of free water for irrigation. Hmmmm

You guys need more snow there. What is gonna happen to your Parrotia if you get some real winter temps without any snow cover?

Bill

My parrotia has a bottle of conac if it gets cold. Have you ever seen where they live in Iran. Kind of cold there too. Montana is a soft warm gentle winter. LOL