Tricky Drainage Situation with SRW

Discussion in 'Hardscaping' started by JimLewis, Jan 27, 2011.

  1. SVA_Concrete

    SVA_Concrete LawnSite Senior Member
    Messages: 467

    move to another area, sounds like beaverton sucks.

    i am surprised there is no drainage easement between the 2 lots.

    here there is most always a drainage easement between back to back lots with open ditch, pipe and DI's or Swales.

    and newer neighborhoods channel that water into a BMP of some sort, typically a pond.

    we just must be a bit more conscious of storm water runoff because of the bay and all
  2. SVA_Concrete

    SVA_Concrete LawnSite Senior Member
    Messages: 467

    one other thought...

    Have you tried to offer a drainage solution to the secondary property? maybe a few catch basins and some pipe to the gutter pan? obviously they have a water situation with a hill running into their back yard.
  3. DeereHauler

    DeereHauler LawnSite Senior Member
    Messages: 604

    seriously, i guess you have never worked on a property with a neighbor? We had a neighbor send us a letter from their lawyer because we were installing a patio and he felt is caused his basement to flood.....seriously, some neighbors are crazy and need someone to blame for everything, never a good idea to dump your drains onto someone elses property.
  4. DVS Hardscaper

    DVS Hardscaper LawnSite Fanatic
    Messages: 6,569

    Buddy, C'mon now and think about this.

    Your pic was self explanitory. Typical Yard scenerio.

    You don't wanna drain water on neighboring property.

    You have no where to pipe the water.


    So then -

    Communicate with your client. You explain that this is a wall system. Not a wall. And for the wall to be a success, everything relies on one another. They probably do not *need* a wall. They probably *want* a wall. So if they really want it, they need to work with you.

    a) you scoot the wall back so water can drain and drain on correct property.
    b) call an engineer
    c) pump water (and then in 11 yrs when the pump's motor stops, so does the water pumping forever because the people forgot the pump existed and now it's just sitting there with a worn out motor. And by this point your client is old and not in good health and hardly goes outside and their kids are handeling everything at the house and don't even know there is a pump there! Long Term - not a good idea because of that scenerio.
    d) drywell of some sort, somehow.

    We do alotta walls. I do alotta estimates for walls. I frequently hear "we can't mow this hill so we want a wall to make it easier to mow" I always think "you're gonna spend $19k for a wall for the sake of mowing, and you can call a mowing company and for $1,200.00 / yr they'll take care of the mowing and you'll forget that slope is there".

    Or I'll hear "we need a flat place for the kids to play". My thoughts are "You have a common area with a nice playground behind your house for your use and you wanna spend 22 grand?" 9.85 times out of 10 when people in a middle income tract home tell me they want to level the yard for the "kids to play" - they end up NEVER doing a wall (after they hear the price).

  5. DVS Hardscaper

    DVS Hardscaper LawnSite Fanatic
    Messages: 6,569

    Just like it's illegal to disturb properly markers, it's illegal to discharge water on adjoining properties. :hammerhead:
  6. JimLewis

    JimLewis LawnSite Fanatic
    Messages: 6,872

    Thanks for all the responses. But I'm going to check out of my own thread. I never really got an answer to the main question I asked several times - and that was; do I really need to have a tile drain pipe behind my SRW or will a gravel drain by itself suffice on a 4' wall?

    But that's okay. I gather the drain pipe is pretty important even though nobody ever really answered that question. So if so, then I think the only real answer is what BrandonV said, which was what I was already thinking. So that's fine. That's what we'll do.

    For those who did understand what I was asking, thanks for taking the time to help me think it through. For those who didn't, I don't care to argue or try to explain myself any more than I already have. I'm moving on to other threads......
  7. SVA_Concrete

    SVA_Concrete LawnSite Senior Member
    Messages: 467

    i think the only person that can give you the answer you want is an engineer. and for your sake -- dont build this type of wall without an engineer

    maybe you can do without the pipe if you put a 1 foot clay "cap" on top of the drainage chimney?

    i recently saw that in a set of specs for a wall around here to prevent un necesarry water from going into the chimney.
  8. DVS Hardscaper

    DVS Hardscaper LawnSite Fanatic
    Messages: 6,569


    No one is arguing with you.

    You're a smart guy.

    Let's think about this, shall we? You have a drainage chimney with no pipe to take the water out. Right? Then why install gravel? Where would the water go? The gravel is not a drain basin, it's a collection point. The pipe is used to get the water to escape the aggregate collection point. And if grading is done correctly, there should never be water discharging from the pipe, the pipe is a back up, last resort system.

    Posted via Mobile Device
  9. MexicanAmerican1

    MexicanAmerican1 LawnSite Member
    Messages: 49

    I think I know, but I want ask, what is the purpose of the drain tile?
  10. steve5966

    steve5966 LawnSite Member
    Messages: 210

    Sometimes, some of you guys just boggle my mind.

    Jim, you do not need a drain tile behind the wall.

    Now for the rest of you, try to follow along with the reasons why.

    You are building a segmental retaining wall. The keyword is, segmental. It is not solid. These are blocks set next to and on top of each other. They are never attached to each other and no seals between the blocks. This means that the wall is pourous, water will move through the wall.
    The drain tile installation that all the books and most all engineers recommend is placed on top of a 1'x 2' trough filled with compacted crushed stone, which is still pourous. For this system to work the pipe must be higher than the ground in front of the wall in order for water to be directed (daylighted) out the front of the wall.
    If the pipe is of the same height as the ground surface in front of the wall, said pipe will not collect water that is draining through the segmental retaining wall. The wall, being segmental, cannot hold water back to fill the pipe.
    You could bury a pipe in your base and that would drain water out of the trough, but that would make your base weaker.

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