French Drain for in laws (pics)

Discussion in 'Landscape Architecture and Design' started by Dogowner, Aug 31, 2004.

  1. Dogowner

    Dogowner LawnSite Member
    Posts: 18

    Great website guys! Did a search on French Drain and believe I'm ready to start this project for in laws. Here is the issue:
    Backyard slopes towards house causing water to pool on lawn and back patio (pic). They had dogs which then get REALLY muddy as lawn is soggy at base. Backyard has existing surface drains (highligted in blue) which lawn doesn't grade towards so they do nothing. They do tie into gutter drain which goes to street.
    Ok so I need your opinion on whether a french drain is the best solution. Does there appear to be enough slope for water to travel down and collect in drain ? Can't get a bobcat in backyard to regrade so regrading grassy area towards surface drains is not an option. See my highlighted line where I want to install 4" french drain. It will wrap around and then connect to gutter drain which goes to street.
    I will then resod entire lawn (excluding gravel part of drain) and hope it works.

    Will be using perforated 2 hole 3" pipe with holes facing downward, fabric wrap, gravel,etc.
    Also I read a 1" slope for drain pipe for every 100 ft. That doesn't sound like enough ?

    Any other ideas on how to deal with soggy lawn is appreciated.

    french drain mockup.jpg
  2. Dogowner

    Dogowner LawnSite Member
    Posts: 18

    Here is the other side of backyard and one of the culprits !!

    french drain mockup 2.jpg
  3. Dogowner

    Dogowner LawnSite Member
    Posts: 18

    Here is where the french drain will connect to gutter downspout and finallly the street.

    I will dig down to find out how deep the existing drain is and then base my french drain depth working backwards towards other side. Sound right ?
    So if existing drain buried 3ft, then I work backwards to end up with maybe 1 ft deep French drain at begining ?

    french drain connect.jpg
  4. Dogowner

    Dogowner LawnSite Member
    Posts: 18

    Ok last photo, they took this last winter showing the water pooling on patio and how muddy the backyard got in that area.

    pooled water.jpg
  5. firststarkid

    firststarkid LawnSite Member
    Posts: 54

    A french drain will work but you still need to change the grade some how on the yard. Put a catch basin on the begining of that drain instead of just pipe it will work even better
  6. steveair

    steveair LawnSite Bronze Member
    Posts: 1,073

    It's hard to really see what is going on from pictures, so I will try and give some general thoughts.

    First of all, where is the water coming from.......Is water migrating streaming across neighbors yard and into the clients back yard?

    If so, the problem may be solved by catching the water before it gets there.....this may be achieved by simply placing a catch basin in one strategic location, or running a 'open' french drain (don't cover with grass, leave the stone exposed) along the property border at the top of the grade or along the edge of the property where the water appears to be coming from.

    Second of all, water or not, this yard may be muddy for other reasons. First of all, it looks well shaded and grass may be having a hard time becoming established. With the added traffic of a dog, it weakens the turf more. When you have week turf, and high traffic, your going to get mud when it rains.

    Maybe a different approach should be considered, like changing the area to a ground cover such as mulch or decorative stone, which won't wear.

    As for the puddle on the patio....that is do to incorrect grade in the concrete......not much can be done with that except either rip it out and redo.

    As for the french drain idea.......french drains work at alleviating subsurface water. Catch basins alleviate surface water. The french drain will help speed up the process of drying the lawn out, but is not going to provide a 'instant' result. Even with a french drain, if the lawn is subjected to traffic after a rain storm, it will still be wet and get damaged.

    Ever watch football? Ever see what happens to the field when a game is played in the rain? It gets destroyed. And its not because of drainage problems. Football fields may have elaborate drains under them, but they can only do so much.

    Same goes for this property.

    My overall suggestion would be this. If there is a considerable amount of standing water that remains after a steady rain, then a catch basin should be installed to at least take care of the standing/surface water.

    After that, if they don't want to get rid of the dog, I would suggest doing some other means of ground cover that isn't going to get damaged by traffic.
  7. Dogowner

    Dogowner LawnSite Member
    Posts: 18

    I greatly appreciate the recommendations !! I needed a drainage expert and you sound like it. I was thinking the same thing in terms of either paving the grass area or lock together stones of some sort.

    To answer your questions:
    1) the water is just coming from usual rainfall in northern, CA. There are no back neighbors and the houses on either side have retaining walls and then their lawns are flat. This backyard never had that done (just gradual slope towards house). Lot is actually like 6" higher than neighbors.

    I thought about 2 french drains one highlighted in red and one at rear of yard. However after reading your response...your right. If you have dog traffic on a wet lawn its going to get destroyed no matter what drain system you have.
    2) puddle on padio not worried about, just wanted to point out that water was getting that far towards the house. Only saw 2 small puddles in crawl space during winter months.

    Ok I'll come up with some alternatives and let them know. I just want to make sure I don't make problem worse.
    Thanks again
  8. Coffeecraver

    Coffeecraver LawnSite Senior Member
    from VA.
    Posts: 793

    My 2 cents

    1) Drain box at downspout
    2) Mulch beds around Japanese red maples
    3) Dog run 6' off existing fence add another
    4)exposed decorative gravel around mulch beds only
    5) 4" corragated drain tile non-perferated from downspout
  9. D Felix

    D Felix LawnSite Bronze Member
    Posts: 1,898

    I would not hook surface drains into downspout drains. It can be done, but if your slope from the drains to where the downspout is hooked in isn't enough, the water can come back up the pipe and out into the yard where you don't want it.

    I'd run a completely different drain line for any surface drains that were installed in the back yard.

    Pictures only tell so much, unless it's blatantly obvious, it is very hard to pick up on subtle grade changes from a picture. Therefore, you probably need to find someone local to consult with. It may be worth a few extra $$ to pay someone to come and look at the yard and tell you where to put drains in and such.

    Oh, and the fall should be somewhere in the nieghborhood of 1" per 10', not 1" per 100'.


  10. Coffeecraver

    Coffeecraver LawnSite Senior Member
    from VA.
    Posts: 793

    I agree the downspout drains should only cary the main source of water.

    The surface drains should be based upon need,after the downspout drains are installed. The heavy water from the downspouts should be in a non-perferated 4" drain pipe and
    carried totally away from the yard.

    The surface drains could be installed in the edge of the mulch beds as french drains, no pipe just decorative gravel in a trench
    about 4-6"deep. Run the drain over to the downspout drain bed
    and connect the two,but not with pipe.The water should travel through the gravel down to the same outlet as the downspout drains.

    When they cannot be installed in the mulch beds,and have to come from within the yard. You could use the silt sleeve on a corrigated 4" pipe and a drain box.

    Dig a hole and install the drainbox,connect the pipe with the silt sleeve on it to the box. Run the pipe to your main drain area,
    cover with gravel and topsoil, only the sod should be exposed
    at ground level.

    The value of the drain installation is at $13.00 a ft. including materials.

    Mulch the trees and create a dogrun


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