1st Qtr 2014: Tech Section: Could this be why your green does not drain?


Do you have 17 well-drained greens, and one that doesn’t perform up to the others, and you aren’t sure why?

 In traveling the country for 30 years looking at drainage problems, I periodically run into a poorly drained green on a golf course that otherwise has greens that drain properly. There are the obvious “problem greens” where the superintendent has already identified shade as the culprit. This is usually a situation where, at first glance, there doesn’t appear to be any reasons that its performance should be subpar.  

In trying to help the superintendent determine what might be different on his problem green, I always start with questions related to possible problems with the outfall piping. Is it on grade; has it been crushed; is it blocked with roots, or contaminated with soil; or is there another potential problem that isn’t as obvious?  If the green is located near a pond, the first thing I look for is if the outfall pipe exits directly out of a lake bank under the resting water level of a lake.

 Seepage drainage is different than surface water from a drainage basin. Piping from a basin can exit below the surface of a lake because the open inlet at the other end allows the atmospheric pressure to equalize the water in the pipe. However, this is not the case with seepage drainage.  

We found this out when we first developed the Turf Drain Siphon System, and installed siphon basins in the bottom of bunkers submerged below the sand level. What we found was that the buried siphon basin had to be vented in order to operate. The soil kept the needed atmospheric pressure from exerting the necessary force to move the water. This is equivalent to the need for a vent cap in a gas can. The fluid will flow, but not nearly at the rate that it will with the vent cap open.

 A clean-out at the top of a green can serve this purpose. Although we have always argued that a clean-out is not necessary in a properly constructed green because there should be no contaminants entering the system (that is a discussion for another time), the standard clean-out can be useful in this application for serving as a vacuum break. Just make sure that the cap has a hole in it and is not solid. If the green doesn’t have a clean-out, then the problem can be easily solved by cutting a tee into the outfall pipe at an elevation above the high water level in the lake.