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Rainbird Central Controller Pro Tips - Flow Zones and Sub Irrigation Class



For the past 4 years I have had the luxury of using a central controller to control our irrigation system. In my travels and consumption of golf maintenance media, I have never read anything with any substance about strategies that superintendents use to program their central controllers. The literature that supports these software solutions are severely outdated and lacking and there are virtually no online tutorials to help managers improve how they use these powerful tools. This blog post will be my first attempt to share some of the ways I use my central controller to effectively irrigate my golf course.

I currently have a RainBird Stratus 2 Central. Sure it looks like it was made in 1998 but it actually has some very powerful features that not a lot of people fully utilize.

Flow Zones - These basically tell your computer how much water each sprinkler zone has access to. The advantage of using this system is that it makes it extremely easy to make quick programs for very specific needs without worrying about turning on too many heads at a time. One of my favorite past times is to diagnose sprinkler issues on google maps. Most often, it is issues with low pressure that is likely caused by turning on too many heads at a given time. It's not super straightforward to set this up so if you don't fully understand it I would suggest finding someone to help you get it working property. I might do a complete post on this at a later date. 

ET - Evapotranspiration is a tool that you can use to determine about how much water the grass uses each day. This makes it much easier to determine how much water you should apply each night. You combine the ET with the crop coefficient (CC) to determine what the crop ET is or how much water you need to apply. You can set each head to a specific CC and the computer will automatically adjust the run time to put down the approximate right amount of water each night. It's a minor difference from using "minutes" to schedule water use but this way allows you to use predictive weather models to make fine tune adjustments with more precision. I don't have a fancy weather station plugged into my central so I manually enter the data each day. It's a small amount of work but not too bad.

Use the default ET number to set the et you irrigate to for the following night.


Sub Irrigation Class - This is a feature that the Rainbird literature has very little information about but is something that I have found to be an incredibly powerful tool to help me manage the various microclimates on my golf course. It is found on the second column of the Station Detail Page. Each sprinkler can be assigned to one of 5 irrigation sub classes. 

Assign each station to a different sub class

I use these to assign each sprinkler a specific attribute. For me, each sub irrigation class represents a different moisture demand or crop coefficient. Our standard CC is 65% and is assigned to the middle sub class "C". 

A - "Super Shade" 30%
B - "Shade" 50%
C - "Regular" 65%
D - "Sun" 80%
E - "Super Sun" 95%

Set up your sub irrigation classes on the Default Data Settings Page. Each Irrigation Class can get their own sub classes!


I can further add different station adjust percentages to fine tune the stations further.

You can also add a max or min ET which could be used to hold back water until you get a high enough et. This is a feature that I don't currently use but I have so many ideas about that I might one day discuss.

I also assign different cycle soak times to each category. If you were a course without lots of shade you could classify the stations by slope or wind exposure and assign various cycle soak settings or CC to each as appropriate.

The insane power of assigning moisture demands work in conjunction with how the flow zones make it easy to make quick programs. Consider this.

I can easily make a program that only waters that areas with the highest moisture demand. This is often what we do in the early and late season where most of our moisture demand is due to tree roots. It is very easy for me to make a program that only waters these areas as we have assigned them in the station database.

I can also prioritize what get watered first. Instead of progressively working through the stations on each hole, I can assign the high moisture demand stations to get the water first. They are most likely to be experiencing moisture stress at the end of the day and will be the first to get relief from that stress. If something goes wrong with my irrigation cycle during the middle of the night, the areas that need the water most have normally already received the water that they need.

DUDE!

I can assign priorities to the different irrigation sub classes to set the order that they are irrigated each night. Dude!


There is a problem with this strategy though. The problem is that the angle of the sun changes as the seasons progress so we need to be constantly adjusting these station classifications. This is done in the field. If I notice that a specific station is slightly too wet, I will make a note on my print out of the current ET adjust % which can be found on the Monitor/Log page. I write a simple up or down arrow beside the culprit station and make the changes when I get back to the shop. Eventually it would be great to be able to make these changes easily in the field but the paper system works really good.

Et adjust % page allows me to see an overview of what sub irrigation class each head is assigned for use in the field and for our records

As we are constantly making changes it seems like just as we are getting things dialed in, we need to make changes again. To save our current setup we simply print off the station adjust % sheet each month and file it manually in a book. The following year, we can use this to make the adjustments before we notice issues in the field. How cool would it be to have a feature that allowed you to save seasonal adjustments like this in the software. Maybe we will get features like this before humans walk on Mars but I'm not holding my breath! haha.

I'm not sure if this is the best way but it is something that I have found extremely useful to help me irrigate our course more effectively and with more precision especially when it comes to moisture demand and when we can supply the various areas of the course the water they need at the best possible time. I hope that one day we can find ways to more easily share how we all used these powerful irrigation control tools.




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