There are many computers on campus and some are tied to much larger items. This happens to be one of those computers. Above you see the computer that runs the entire irrigation system for CU Boulder. With this computer I'm able to initiate, control, adjust or stop irrigation operations on campus. Just like a home irrigation controller, everything comes back to one singular control point. This post could be very long if I was to cover all the options that are possible with this system so I will focus on three things.
The first portion being the Control System for the Site Pro program.
I apologize for the large size on the above picture but it needed to be bigger so you would be able to see the items. What you see is the control system for one of our 68 irrigation controllers. Within this page resides all crucial data for every station within that controller including location, amount of heads, station flow and most importantly, station percentage adjustment. The ability to adjust every single station by itself is one of the greatest benefits to having a central control system. In the third column from the left you will see the header labeled %Adj. This column represents adjustments that have been made to the individual station. The adjustments are crucial especially with the amount of microclimates on campus. Within one area we can have south facing sloped landscape and then on the north side of a building we could have flat grade and no sunshine. This makes proper irrigation extremely challenging without the ability to adjust individual stations. An example of the adjustment would be, I chose to irrigate .25" of water on a given night, but a location may need more water to compensate for a south facing exposure. So that station may be adjusted to 125%. This represents 125% of .25" of water. The opposite is true as well, where I may have an area that is very shady and low lying so it only need 75% of .25" to satisfy the plants needs. It honestly can take years to properly adjust the system so that when I irrigate a certain amount everything gets what it truly needs and we are not over watering/underwatering. I'm in my tenth year of adjustments and for the majority of campus we have a good handle on all the microclimates, but each year with new construction and landscape growth I find that adjustments are still routinely done.
What you see above is a small portion of what is called the Hydraulic Tree. Unlike the control system this section of the Network is not adjusted unless a new irrigation system is added to the database. Inside this section you have every single pressurized irrigation mainline on the entire campus. For a station to run on campus it must be "attached" to a "pipe" in this section. Each "pipe" has a max flow. The maximum water an area can deliver is set based on the Pump Sation feeding that area. So in this case we have the Varsity Pump station which delivers 750gpm at max flow. Each night before programs are loaded to the clocks Site Pro runs a projected flow graph. This is a way for the computer to determine which zones run and for how long on each pipe. The most crucial portion of this data is the flow management. If the incorrect data has been input then we can have problems ranging from low station pressure all the way to breaking mainlines. Needless to say we pay very close attention when we are in this area to make sure everything is done right.
The final section I will discuss is our Weather Station
Currently we have our own weather station which we use to monitor many things. As you can see above we can monitor every important piece of information that a Turf Manager needs to help make decisions about the need/amount of irrigation for a given night. This station gives us an important piece of information called the ET factor. Also known as evapotranspiration, this is the amount of moisture returned to the atmosphere during a given time from the soil and plant transpiration. This is a rough representation of the replenishment a given location may need during the next irrigation cycle. But this is not the only information a Turf Manager uses to determine the amount to put down in a given cycle. Root development, cultural practices, plant species, soil type, events, traffic, as well as the inherent knowledge of your landscape are all factors to help determine a specific amount of water to put down. I have been asked in the past if the ET factor says .25 why don't you just put that down and call it good. The factors given above help to illustrate that the ET factor is just a piece of the decision making puzzle.
The other benefit of the weather station is that I'm able to set alarm parameters which help to prevent the wasting of water. Currently I have limits for strength of wind and also for amount of rain. An example is if I have an irrigation cycle scheduled and a surprise rain storm pops up either late in the evening or during the night and we recieve .10" of rain during a set amount of time, the computer will shut down the irrigation cycle for the rest of the night. This also is true for wind; it will cancel the rest of the irrigation cycle. The reasons for the shutdown is obvious, but having the ability to protect our water resource is just as important.
As you can see from these few items, we take irrigation practices pretty seriously here at CU.