I have a corner in my yard that is getting too much water from the sprinkler system. The grass is drowning and moss is growing because it's constantly wet. The adjacent zone seems to throw enough water on that spot. Can I somehow cap off that one rotor, or will I need to completely remove it?

If capping, is it a matter of replacing the rotor with a cap. If removal is necessary, will I need to remove that whole spur pipeline, or can that branch just stay in ground full of water?

2 Answers 2


It depends on where the sprinkler head is located within that zone. If the sprinkler head that you are capping is not a dead end on the line, then you can cap it at this sprinkler head. If it is a dead end, then you need to go to the prior sprinkler head to cap the line.

A dead end occurs with the last sprinkler in a series. Capping a dead end leaves water in the underground line with nowhere to go. If the sprinklers are spaced far apart, this wastes water pressure. In areas prone to freezing, it can cause water in the line to ice and damage the pipe. Dead ends should be capped at the preceding or next-to-last sprinkler head.
Reference: http://www.doityourself.com/stry/how-to-cap-off-a-sprinkler-head

And you do not replace the rotor with a cap but actually just remove the sprinkler head and cap the line. Removing the sprinkler head is very easy to do. Just get a trowel and dig down around the sprinkler head until you have enough clearance to unscrew the current sprinkler head without getting soil in the line.

But before you start the work on capping/removing this sprinkler head, I would try adjusting either the current sprinkler head or the other zones sprinkler head to reduce the amount of water being delivered to that spot. Depending on the type of sprinkler heads you have, you might be able to replace/adjust one or both of the sprinkler nozzles to reduce the flow. Or look into adjusting the pattern on the sprinkler to deliver less water in your area. Or you can even reduce the amount of time that one of these zones is watering. My point is that someone already did all that work to install the line and sprinkler so try some other steps first. There have been plenty of times that I have planted a tree or plant or did some other landscaping that blocked a sprinkler heads spray area and then wished I had another head in that location.

  • 2
    I don't understand how a capped dead end wastes water pressure. The argument about freeze protection is sound. Jun 19, 2012 at 20:38
  • So is there really no such thing as a closed cap that can replace and close off an existing sprinkler head? I've got a somewhat temporary situation with a playhouse on top of a sprinkler head. It waters the inside of the playhouse when the sprinklers are running :) May 24, 2014 at 1:56
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    I use caps for the risers to troubleshoot problems often. My sprinklers are attached to risers, and I often unscrew the sprinkler, add a riser extender to make it easier to avoid getting mud in it, then cap the top. May 22, 2019 at 4:33

It wastes water pressure if you cap it at the sprinkler b/c that entire line still fills with water when the system is turned on. That part may not be totally empty when used day to day but its a line that still will utilize some of the flow whenever used. In places where winter = freezing, each fall the lines in the system need to be bled of any water so they dont freeze and crack the pipe or the sprinkler assembly during the winter-when you dont see it or know it. The line blocked at the sprinkler will never be bled, -one day it may freeze, crack, and leak when the system is used again in spring, and you will need to find another part of that line and cap it again. Try to cap it close to the manifold end, not the sprinkler end. The shorter that line the better.

  • 2
    The part about it potentially freezing is correct. However a capped-off pipe will not affect the upstream pressure or flow.
    – mike65535
    May 20, 2019 at 13:06

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