How do I install lawn drainage for a soggy lawn?
My backyard slopes slightly away and to the left of the house. The rear part of the lawn and the left rear corner are swampy after any rain and I need some effective lawn drainage. For the drainage pipes, I think I have to dig a large trench along the back fence, line it with landscape fabric, and fill with gravel, but am not sure of the dimensions (ie. how deep, wide, etc.).
Do I also have to dig smaller trenches in the direction of the slope and connect them to the large one?
Do I fill these with gravel, too, or sand? Any other suggestions? Thank you. If there are any professional drainage contractors out there I would be very pleased to hear from them.
5 Responses to “How do I install lawn drainage for a soggy lawn?”
Your on the right path. As long as the lawn drainage ditch starts in the swampy area and doesn’t go back uphill you shouldn’t need connecting ditches unless you need to drain the area fast.
As a rough guide I would calculate the volume of the area you need to drain and add 50%. (length x width x depth of soggyness or standing water+50%) This should be enough area to take the water. Depth and width are variable based on the length you have to work with. I never go less than 12 deep and deeper is better if you can do it. The fill mix should be gravel and sand so the soil doesn’t wash in fill between the gravel.
The best solution is to have your lawn area graded with a minimum of 2% slope towards the street.
Since your property is already landscaped, the next best thing is to install a 3 or 4-inch diameter (plastic pipe) from the rear of your lot to the street. You should have a drainage pipe on each side of your house (if possible) taking the water from the rear yard to the front yard and out to the street. The drainage should be buried 6 inches or more under ground and have at least a 1% slope as it heads towards the street. The drainage pipe should be place under the public sidewalk and drain directly into the street gutter. You can have a hole drilled through the street curb and gutter and a pipe installed under the sidewalk for about $75 to $100, (a second one would cost a little less). Be sure to check with the City or County Government before you cut the street curb and gutter, they may require a Permit.
You can buy the 3 or 4-inch drainage pipe at Lowes, Home Depot, Ace or your local hardware store. Be sure you buy drainage pipe and not the black sewer pipe. Drainage pipe can be solid, have 1/4 inch holes along one side, or be a black flexible pipe with small holes all around it. You will also need to get connectors, T’s, 90% elbows, Y’s and inlets to allow water into the pipe.
I would not use trenches with gravel or French drains because this would be more impactive to the landscaping as well as your wallet.
Hi:
You have the right idea. Your main goal is to divert the water away from the foundation. I am a landscaper and designer and live in an area where many houses are on slopes. I have done new constructions and put many lawn drainage pipes in as well as drain boxes. These are all possible solutions to your soggy lawn. I will link you to the simple solutions section of my website. I have a page on landscaping with corrugated pipes. You will want to use a solid pipe to divert your water. If you have down spouts on your house you can attach some piping to the spout to help with the water flow.
I will also link you to the site map as this page has everything that is on the website. Browse through as there are many articles, tips, and techniques that you may be able to use. The website on easy digging has a good tool. I have the site also on my information section. Good luck to you and if you need any further help, let me know! Have a great day!
You have another alternative to digging and filling. You can build a bog garden. It will create a pretty space in your backyard and not send all that water to the water treatment plant. Here’s how to do it:
If you want to do a lawn drainage system drain tile will work well as long as you have a place for it to outlet. Chances are that if you do drain tile or a french drain you will have to put in a dry well for those systems to drain into. If it was my yard and it wasn’t a huge area I would peel the sod up regrade the area to stop the water from pooling and put the sod back down.