Backyard Drainage Issues

Question

I recently had a sink hole in my backyard that I consulted with here on DIY and got some helpful responses. This was as a result of an old well. It was fixed by a landscape architect.

However, after some more heavy rain I can now see other issues that my back yard is having with drainage. Can anyone recommend additional drainage fixes?

Along the side of the first picture I have three french drains. Those drains hook to a larger drain that goes to the main neighborhood reservoir. They do not seem effective though, and neither does the mulch as it just flows downward. Water flows onto the deck posts and soaks them, as well as along the back line of the yard and down to the lower side as you can see in the pictures. I am thinking this is where the issues lie - need a better solution here.

In the second picture (yes I know, its blurry but it was raining heavily) you can see some standing water in the grass which I have highlighted. Some water flows along the back fence/grass line which is fine. I obviously can't force a drain line to flow into my neighbors yard as this is illegal.

That water all comes down along the fence line next to the neighbors house which sits lower than mine. It piles up along the side of my house as you can see in the third picture. Maybe that needs some french drains as well?

Answer 1

I had nearly the same problem and a single french drain made the problem go away. It is important (and probably worth reinstalling if not done) to have:

• a 10% grade (1 inch down for every 10 inches of pipe length)
• cloth covered french drain pipe
• plug off the yard-end or open it to a ground level drain (cloth and grate covered!) and make sure you can access it to clean it out
• make sure your trench is at least 8 inches wide (2 inches clearance on either side of a standard 4 inch french drain pipe)
• place the french drain pipe in a channel that has 1-2 inches of pea gravel for a bed
• cover the pipe with at least 2 inches of pea gravel before putting in the dirt

The french drain also should start prior to the onset of the wet area. (Please note the image does not accurately reflect the opening of the yard end - i.e. you can't clean this one out!)

Answer 2

I had this exact same problem when I purchased my house four years ago. 90% of my gutters drained to the side of house along with along with 90% of my neighbors gutters. To further complicate the issue my neighbor has a ton of tall bushes that shade the area, so any time there was a heavy rain water would sit there for up to 3-4 days. I put in a french drain exactly like b-p suggests above, EXCEPT I ran the french drain all the way down the side of my drive way to the curb with a pop up valve on the end. I haven't had the slightest puddle of water there since then.

Answer 3

With heavy rain it takes time for the water to filter into the French drain. (Water making it through the roots and dirt over the drain) The distance & slope also affects the speed that the pipe can empty. One additional drain on your side yard to the reservoir should help eliminate the standing water there.as long as the reservoir is not full. As others have suggested make sure they have not filled up with dirt, I like using the pipe that has a sock on it to reduce the dirt entrance (it moves through the gravel over time).

Answer 4

Oh another oldie & surprise-surprise another moldy "professional". Pitiful! What no Warranty? Yep, you got the "Landscape Architect" treatment alright. Another waste of money on a Certified & Degreed horrible idea. That ain't no French Drain that's dumb Drain Tile (a dumb name too).

Always try nature first & foremost! Since there's a downslope to a reservoir then there's a down slope to fix both properties permanently. It's called a swale or gully & it doesn't clog up & the water's already done half of it for you! Another "secret" is that you can bring dirt in to make a slope or make it a bigger slope...truly amazing!

Build-up the back or if that's lower than the houses too, take dirt out & put it between the houses as the high point. And, the front just needs to be taken down to the curb. You can see the water wants to go there, but it can't. Most everyone needs a Land Sculptor & most no-one needs a Landscape Architect!