# Expected Uniformity of a 4'' Popup Sprinkler



## effektz (Oct 11, 2019)

Hi all! Long time lurker, first time post! I had a question, in the middle of my back yard it appears that my lawn is very dry or over stressed compared to the grass surrounding it. I did a 15 minute test on the sprinklers that I believe should be distrubuting water to that area. The area that has issues begin roughly around 10ft away from this sprinkler head. I am not sure what brand sprinkler they are but they appear to be standard rainbird 16'' throw ones you find at Home Depot. If it helps understand it, this one is a half-circle pattern and there was no wind when the test was taken.

To test I placed 3 cups at 3 different distances. I placed the first one at 5ft, second at 10 ft and third one at 15ft. I ran the sprinklers for 15 minutes and measured each cup, below are the results.

5ft cup - 5/8''
10ft cup - 1/4''
15ft cup - 1/16"

Is it normal for a pop up sprinkler to have this drastic of a drop off at these distances? Should I replace the sprinkler or is this normal that a new one would make no difference? Below I've included a picture of the back yard and the red circle is where the sprinkler in question is. I appreciate the help!


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## dpainter68 (Apr 26, 2017)

I'm not very familiar with the uniformity of the standard pop up nozzles, but my first question would be is there another head in the middle of that dry spot spaying back to the head in question giving it head to head coverage? You may want to consider rotary nozzles if your replace it. My understanding of them is the uniformity is much better, although I haven't done an audit on mine yet.


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## Ware (Jan 28, 2017)

Do you have head-to-head coverage? Irrigation heads require 100% overlap to achieve uniform distribution. Here is a nice graphic from irrigationtutorials.com (<- and a really great article at this link) illustrating the importance of head-to-head coverage:










So heads are typically arranged in a square or triangular pattern so that every head sprays all the way to the 2-3 heads adjacent to it:


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## effektz (Oct 11, 2019)

This one does not have head to head coverage. There are 3 large rotating heads in the flower box on the right side of the picture that throw water a good distance. I've only owned the home for a few years and it was put in 10+ years ago when it was built. I'm assuming that's my issue is the lack of coverage. To fix would it be helpful to run an additional sprinkler to the middle and use a 360 degree spray head on it?

I'm going to make a detailed drawing of my sprinkler system this weekend as I believe there are too many sprinklers in one zone but not enough in others


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## effektz (Oct 11, 2019)

The rotary heads in the back are Weathermatic Turbo 3 heads


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## effektz (Oct 11, 2019)

In case others have the same issue, what @Ware wrote above is correct. The sprinkler heads that were used on my lawn were incorrect. Looking at my neighbors systems this weekend and saw they all have rotators in the backyard where mine had the spray heads. I went to Home Depot and bought 1/2'' Rotating Sprinkers and swapped them this weekend. Did water test afterwards and now the areas that were not receiving a lot of water were correctly receiving it.

Thanks @Ware


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