Irrigation Pump Station Issues

If you've played the course in recent weeks I'm sure you've noticed more turf stress, particularly on the fairways, than you are used to seeing here at Quilchena.  Some of this stress was expected as we haven't had a significant rainfall since mid-June, but some of what you're seeing out there is due to some irrigation issues that we've been experiencing when running our nighttime watering cycles; pressure loss issues to be exact.  We recently became suspicious that we might be experiencing some pressure loss due to the distinct pattern of healthy vs. unhealthy turf on our fairways.  We are used to experiencing turf stress on the fairways during prolonged droughty weather conditions, but not like we've been noticing lately.  Again, this led us to believe this turf stress may be caused by more than just drought.

When we run the irrigation system during the day we can see the sprinkler heads operating and quickly notice any deficiencies.  Daytime irrigation consists of very short watering intervals as the goal is to syringe or simply cool the surface of the turf during the heat of the day and we are running very few sprinklers at a given time so pressure loss is never a concern.  The intent of nighttime watering cycles is very different.  They are much longer cycles with the goal of moving water through the soil profile to the root systems of the plant.  Yes, our poa annua roots are quite shallow during the summer months, but this "deep watering" also helps to "flush" the soils and prevent them from becoming hydrophobic.  These irrigation cycles do not start until after we are certain the golfers have cleared the golf course, for obvious reasons, which is typically between 9pm and 10pm during the summer months.

With the course being closed for aeration this week, we had an opportunity on Wednesday evening to start our nighttime irrigation early to observe the system running and determine if it was operating properly.  It didn't take long for us to realize that we were correct in thinking we might be experiencing pressure loss.  Shortly after the watering cycle began we could literally watch the sprinkler heads losing pressure, right down to where they were watering about 50% of their targeted area.  

Here is a sprinkler head on #7 fairway operating with low pressure during Wednesday evening's cycle:

low pressure causing this sprinkler malfunction

Here is that same sprinkler head operating with proper pressure the following day:

proper pressure allows it to water the entire target area

As you can see, proper pressure is crucial for our irrigation system to function efficiently and effectively.

We have discovered that the pressure loss issues were a result of one of our three 60 hp pumps not "kicking in" to help the other two pumps maintain a system pressure of 120 psi when the demand from irrigation running on the course was requiring it to do so.  We have since adjusted the pump settings in the control system to ensure each pump does indeed turn on as it is required.  These adjustments we made should also allow the system to operate more efficiently which, in turn, should reduce the wear and tear on the pumps and hopefully reduce the electrical costs of running them.

On the bright side, being here late to babysit the pumps on Wednesday allowed me to snap this photo of one of the most amazing rainbows I have ever seen:

"double" rainbow

Oh yeah, we also aerated this week, but I'm going to let Josh let you know how that went in his Herald article.  I will say though that we are very pleased with the results and here is a sneak peek of what the greens look like today, just one day following the aeration process:

we anticipate a speedy recovery from the late-summer aeration