Working around natural/planned site drainage

Discussion in 'Water Features' started by fmjnax, Mar 26, 2008.

  1. fmjnax

    fmjnax LawnSite Member
    Posts: 21

    I'm about ready to start digging my new pond, stream, and waterfall in the backyard. However, no matter which location I choose (I've designed it at three different locations), my stream will be crossing the drainage plan of our yard. I will try and explain:

    The two halves of our yard slope towards the middle (the back half has much more slope than the house side, which is almost level), creating a drainage "channel" from one length of the yard to the next, which then empties to the rough "French drain" that takes the water in between the houses down towards the street.

    This channel that is created is going to be a pain to work around. The site I've chosen for the pond will be fine, not even coming close to the channel. However, when I add on my stream and waterfall, the stream will intersect with the channel. I have been trying to find some way to work around this so that I don't get drainage into my pond (fish pond, but not a koi pond). I'm clueless, though.

    Best idea I could come up with would be to pipe the drainage channel under my stream (my stream will only be about 1' deep and a few feet wide). However, I would likely have to come up with a way to pump the water or pipe it about 30' at a slight grade to the side of the house where it can empty into the "French drain".

    Another alternative would be to alter the bisecting channel to have it flow to the opposite side of the yard. This would require either regrading my yard (not likely) or creating a true French drain about 50' long.

    So, how can I go about working around my drainage problem? Do I even need to worry about it? I will work on finding my camera to snap a few reference shots.
     
  2. Infinity Landscapes  Inc

    Infinity Landscapes Inc LawnSite Member
    Posts: 168

    Install a dry well near the pond and run your drain into that then hook up a sump pump since you will have power near the pond. You can then hard pipe it to the street. pics would help. good luck
     
  3. fmjnax

    fmjnax LawnSite Member
    Posts: 21

    I will try to get some REAL images tomorrow, especially since the last utility company will be out tomorrow to mark their lines. My wife can't remember where the digi-cam is. However, I do have some pictures from my cell phone. I marked them up with my preferred plan a while back:

    This image shows the overall yard. From house to the stone retaining wall (which is about 3' at the lowest and 4' at the highest) is roughly 36' at the line. I believe it's 27' from the corner of the house. The black circle indicates the lowest point of the yard. Red lines indicate the drainage.
    [​IMG]

    The next hree images show my proposed layout of the pond/stream/waterfall. The blue lines in the first two images is the typical yard drainage. In both images, you can kind of see the residual path from the recent rains before the pictures were taken.
    [​IMG]
    [​IMG]
    [​IMG]
     
  4. Infinity Landscapes  Inc

    Infinity Landscapes Inc LawnSite Member
    Posts: 168

    It looks like you have drainage going both ways away from your pond. You can berm around the pond to help divert the water. You should have plenty of dirt to make good grade changes if indeed your drainage is going two ways. In you pond install a pressure relief valve to help if you get any water build up below you pond it will let the water in to take the pressure off the pond. Other wise you will end up with a big bubble..I would also install drainage above and below your retaining wall to lessen the amont of water on you property Or take the drainge away from you pond and install a dry wells and pump it to the street. Hope this helps.
     
  5. fmjnax

    fmjnax LawnSite Member
    Posts: 21

    That does help, Thanks GMP,I. We do have drainage from both sides. One of my thoughts was to regrade this side of the yard to drain off to the other side (and you're right, I'll have plenty of soil to do the trick). However, we are in a very thick black clay area, so the less soil work I have to do, the better. I like the berm idea around the pond. That will look nice, I think, and server a lot of functionality. I also like the dry well idea. I would LOVE to be able to install drainage above the retaining wall (like a french drain), but I will have to check the HOA code on that. I know it specifically states we can't alter the retaining wall. I'm not sure where drainage ABOVE it would fall in to place.

    The one thing I'm confused about is the pressure relief valve. Can you go into more detail on that please?
     
  6. Infinity Landscapes  Inc

    Infinity Landscapes Inc LawnSite Member
    Posts: 168

    You can look around this site for more info on relief vaves or call you local supplier. If to much pressure builds up below the pond I.E water then @ a certain psi the relief valve will open into the bottom of the pond. or bring in top soil and build natural walls and elevate the pond. check behind your wall for a french drain. Or add a french drain at the base of your wall.
     
  7. fmjnax

    fmjnax LawnSite Member
    Posts: 21

    I'm in the process of leveling out the pond site and will start building up the berm around the pond as I excavate the pond. Before I put in any work on this, I want to make sure I will be installing the pond liner correctly. Would I drape the liner up and over the berm or would I lay the liner and build the berm on top of it? My gut says that the liner will go OVER the berm, but I want to make sure.

    Thanks!
     
  8. Infinity Landscapes  Inc

    Infinity Landscapes Inc LawnSite Member
    Posts: 168

    your gut is right always over the top. Always leave 6-8" of extra liner and fold it under. alway cut it at the very end after all the rocks are set. never know if you will get some settling and need extra.
     

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