Irrigation

Recently this summer I have had a lot of questions about watering practices and how it impacts playability.  I thought it would be smart to write some facts down to give our membership a little more info on how we water and what equipment is used.

IRRIGATING EQUIPMENT

To start, we our in great shape from the stance of our current irrigation system including everything from piping, electrical, sprinklers and a central computer operating system.  In 1999 a new complete Rainbird Irrigation system was installed at the club.  The most important factor with this system besides new piping and electrical is that it enabled us to have "single head control".  Prior to the 90's they had what was called a "block system" meaning that when you turned on one station(sprinkler), three or four irrigation heads would come on at one time.  This block system made things very difficult because you could have a hot and wet spot right beside one another and not be able to adjust the percentage of water accordingly.  Currently with single head control I can adjust the percentage of water for every single rotary head on the course, meaning if I have a dry spot I can turn that head up and a wet area, turn one down.

This is an example of what a case and rotary look like.  You only see the top part of this.

In 1999 our irrigation system included 1,571 of the heads pictured above.  Those 1,571 heads can be split into 2 categories.  One is what we call a 700 series.  The 700 series is a rotary that waters a full circle or 360 degrees.  The other type is called a 751 series and this head generally will only water a half circle or 180 degrees.  Of those 1,571 heads 1,039 of them where 700  series and 501 where 751's.  The main difference besides coverage of turf is water usage.  Both of the heads put of roughly 25 gallons of water/minute.  That's right, 25 gal/minute.  The main difference is that the 751 on nightly basis only puts out half as much water because it's irrigating half as much turf.

Example: On a summer evening we run about 8mins of water.
So that translates to a 700 running 8mins @ 25gallons/min. = 200 gallons of water for (1 head)
A 751 only needs 4 min because it's watering half as much. A 751 will put out 100 gallons for 1 head.
 This info is important because the more heads that we can convert from a 700 to 751 the more savings we will inherent.  So this gives you a basic idea of what is in the ground out here on the course.  Please remember that I can individually adjust all of those heads because of single head control.  The base line in our irrigation computer is 100 percent, so if I have hot spot I can adjust that head to water 150 percent.  The same thing can be done for a wet spot,  I might have the percentage at 50 percent.  My three section leaders(all 30++ years experience) along with my assistant and I are touring the course on a daily basis looking for heads to adjust.  I have to say that after three years of constant adjusting we have the heads pretty much dialed in.

 The next question would be how do we come up with the amount of water to put out on the course on a daily basis. I use a few different components to determine the amount of water to put out or run.  Let me start by saying that our goal is to only supply the plant with enough water to make it through the day so that in return we provide the finest playing surface possible. The first component we use is our weather station.  You can can spot our weather station to the left of the 1st fairway. 

This is what our weather station looks like.  It's located to the left of number 1 fairway.

 This weather station monitors on a daily basis the maximum and minimum temperatures, wind speed, relative humidity, rainfall, and solar radiation.  It's main function is using a calculation with the factors mentioned above to determine the evapotranspiration rate or E.T. Evapotranspiration (ET) is a term used to describe the sum of evaporation and plant transpiration from the Earth's land surface to atmosphere. Evaporation accounts for the movement of water to the air from sources such as the soil, canopy interception, and water bodies.

So with the weather station calculating the E.T. it will come up with it's recommendation for nightly irrigating.  The number of minutes to water is the amount of irrigation to replenish the plant to make it through the day.  The weather station is just one tool we use to determine the amount of water to run. Some other factors include daily observation of  turf health, how does the turf look, probing the soil to check soil moisture, and the 10day weather forecast. All of these and more factors determine the amount of irrigation to run.  We will ALWAYS error on the side of being a little dry knowing that it provides a better playing surface unless we are experiencing a severe heat wave.

TURF SPECIES AND ACREAGE
It's funny because with all of the increases in water  I have had more comments in the last month about the course being over watered than I've had in 5 years.  Before we converted to rye grass we did at times have unplayable wet conditions because of Poa Annua's shallow rooting and susceptibility to heat.  There's not much you could do in order to keep the Poa alive but over water it.  Fortunately our conversion to rye has allowed us to provide more acceptable playing conditions.  The great thing with rye is that it will recover from heat stress where Poa will just die and leave a void in the turf.  This allows us to run things a lot drier and not worry about loosing massive areas of turf not to mention save on irrigation.

In 2007 we were irrigating 100 acres of turf here at Palo Alto.  Currently we are irrigating 80 acres of turf thanks to our implementation of native areas and straw beds.  That's a big difference.  We have been able to turn off 103 irrigation heads(700's and 751's) because of the native areas.  The straw beds added another 53 heads that we could turn off and both areas combined allowed us to convert approximately 150+ heads from a 700 to a 751.  Looking at those numbers you can see that we have saved some serious water.  To give a idea in 2007 the club was billed by the city of Palo Alto for 80,119,776 gallons of water.  In 2009 after the full conversion and installment of native and straw beds the club was billed for 51,574,600 gallons.  That a difference of almost 30,000,000 gallons.

MOVING FORWARD     
First, I would like to say that I could talk about water all day long.  The information  above is just a starting point.  What I hope you received from this blog is a basic understanding of some key components involved in irrigation, changes we have made to conserve water and to know that irrigation is at the top of our list when it comes to priority.  We are doing everything possible to provide the best playing possible while using the least amount of water.  Moving forward we will continue to explore all pathways to find conservation with water.  Please feel free to stop me on the course or come by the office to talk more about water.