8/1/2012 7:08 AM
I copied this from a thread a year or so back. This is how we handled our in-house greens drainage.
Josh, Greens drainage is really not that difficult as I said above. If you have done any drainage work before you can complete greens drainage. There are no short cuts in draining greens though. I will discribe how I drained one of my greens in two days and try to keep it brief and to the point. Others may chime in with other suggestions that make it even easier.
you need a few things to start with. first you need to look at your green and assume that the sand base across the green is in the same mold as the the surface. You could use a soil probe and actually measure the sand base to get an idea. next is you need a place to drain to, a ditch, pond or even the lowest point away from the green (hopefully 200'-300') also it is better if this area is on the same side of the green as your lowest point (where the water runs off). My greens all sloped from front to back so all of my drain lines flow to the front corner. I prefer using a herring bone design drain system. I basically run my main line (4" socked pipe) either down the collar or down the green depending on the direction the water may move on the surface. it is best if you run your drain lines where the water travels across the lines and not with them. It helps to understand water in the subsurface of the green will not move as fast as on the surface but you want the water to dump into the trench. once a design is chosen and a place to run the line to is determined you are ready to move to the next level. (I have many greens that run to a shallow ditch and bubble out of a catch basin instead of an open pipe that will flow, but this is because I do not have enough fall to just drop it into a deep ditch. It still works great. they have been working great since 1997.
Ok lets say you are ready for the next step. We rented a small walk behind trencher, we purchase a dozen sheets of 3/4" plywood and cut them in half longways. We tied heavy ropes to one end to make it a drag sled. We cut the sod up from our desired trenches, rolled them up into sections that can be handled and moved off of the green under a shad tree. One very important part here. Roll every trench and piece of sod in the same direction. start picking them up from the same end of the trench on every trence and make sure they are stacked into rows exactly how they came off the green. this will ensure that the sod goes back exactly how and where it came off the green. If placed under a shade tree rolled up they will keep with no problem over night (at least bermuda will)we lined the sleds up on each side of the trench we were going to cut with just enough room for the trencher blade to fit in between. We started at the lowest point in the green and trenched 18" deep (you can go 2' if you want it deeper but my sand base was only 8" deep) I cut every trench at the same depth and leveled them out by hand. I cut my latterals at 15' but have heard of some going 10'. when we completed a trench we used a small tractor with smoother tires to pull the sleds off of the green into low spots nearby or made a pile to pickup later.
Ok lets say you completed all of your trenches. Now you need to simply make sure they are all level and water flows. use a trench shovel (narrow) and clean the bottom or level it out and then add 2-3" of sand or rock to the bottom of your trench to form a clean base (we used sand) install your drain lines (we used 4" socked pipe for our main line only and used what we called waffel pipe for all other lines. After the drain lines are installed you will need your sleds again to back a dump trailer or you can use a small utility vehicle to bring in your sand. I used two broom handles to center the waffle pipe while my crew dumped sand over them. you only need to get about half of the waffle pipe covered for it to stay in place. After all lines were sanded we filled the trenches up with sand to about 3" from the top of the trench. I then took a water hose and placed it under the sand in the trench and flooded the sand out making sure that I got all air out of the sand (think of it like packed beach sand after the waves roll in, it get sreally tight). I personally worked this part and then had more sand added to top it off with and flooded that sand too. Doing this part right will lessen the sinkage of your drain lines and also make less work for you in topdressing the lines to get them smooth again. On my latter greens I actually mixed a little peat into a pile of sand for my top 3-4" to lessen the hot spots you get on drain lines ("very important" do not use the water asorbing crystals in this area and if you do make sure it is only a very little bit because I have seen one super do it and after the first hard rain we had speed bumps where our drain lines were and had to dig them all up, it is so nice to learn mistakes from others). your last part is installing your sod. Roll it back out in the opposite direction you rolled it up making sure you put the right sod in the right trenches. Use your most dependable people on this part because you will have to add sand by hand where it is needed as you place it down. If you have done a great job on the water flushing you will see very minimal sinkage in your trenches. Also make sure they tighten up the sod when laying it, by this I mean that when it gets rolled up it actually stretches out so as them roll it back out they have to push it back or else you will end up with a lot of left over and your trenches will be low. you will have left over sod from each trench, hopefully not a lot.
We split the job into two days, the first to trench and remove everything and the second to put everything back together and worked about 10 hours each day with about 6-8 people. if your greens are really wet you may have to push the crew to get your drainage installed and centered before quitting in hopes of keeping the sides from colasping in.
I know when reading this it may seem like a lot of work and it is but the cost was minimal and the results where spectactular and our members only had to skip the green for two days (I think we asked them to play two balls on another hole if they wanted to use their score).
I have drained 40 greens to date in this manner, but the last time I needed to do one was in 1997 (it is great to renovate all of your greens and stay at one place for 16 years). I am sure there are other ways and even better ways but I think I average less then $500 per green and saved my job at the time. I would do 2 greens a week with no problem but be careful not to burn you crew out. you may do 1-2 weeks and take a couple of weeks off to maintain the course before moving on.
I hope this helps. I work at a very low budgeted course and did what we could with what little we had. If I was doing them again I might think about using a dingo machine since I could also use the bucket attachment to spread the soil I remove or load my trailers or work vehicles.
Use straight sand at least in the bottom section of the trenches where you water will need to move along the sand base. I had thought about using the soil we removed but felt better about going with new soil.