Understanding the Science of Hot Spots

Taller Turf Affected While Shorter is Not

Every year as the conditions that are least favorable for the ryegrass survival occur, the membership poses concerns about the increased hot spots that they did not see during the season.  Then these members or other members play other golf courses and what to compare the newly played course to ours ... I can understand the need to want to do this and understand their concerns.  But let's look at the "hot spots" we have just on 17 & 18.

Looking Down 18's Fairway at Even Spaced Hot Spots

As you look down 18's fairway you will notice one thing right off the bat ... the "hot spots" are evenly spaced and follow a pattern down the fairway ... Why?  Looking into the matter further you will notice the these same hot spots are on the eastern edge of the irrigation head that is neat to ... Why again?  Fact, grass doesn't die in patterns naturally.

Looking Up 18's Fairway at the Even Spaced Hot Spots

Then using 18's fairway as the guide you will see that it appears that there are two rows of "hot spots" both of which are on the eastern side of the head ... Why again?

There is several reasons for why you are seeing this pattern, but first I have to quickly explain how the irrigation system is set up.  The system is designed as a triangle pattern which has head to head coverage to produce the most uniform distribution pattern (you can Google this term if better understanding is desired). 

Our wind lately have been coming from the west in a eastern directions at sustained speeds of over 30 MPH and gusts up to 70 MPH.  Thus the heads to the east of the "affected" hot spot head never reach the head and do not give the required overlapping as the system has been designed -- thus a pattern of "hot spots" east of the heads.

The Famous "Donut"

That explains the patterns that may be seen but not everything.  Some of the issues are because the HOC of the turf ... higher the cut, the higher the transpiration rate, and with ryegrass which is a winter grass for us ... death! 

Some of the issues are the age of our nozzles and the age of the heads themselves.  As the nozzles wear out the uniform distribution pattern deceases greatly.  This nozzle issue has been linked to overwatering to compensate for the uniformity issue and has been addressed by water districts around the State of CA ... Google this and you will see that it was so important the districts paid for the re-nozzling of courses in areas such as OC and San Diego because the water loss was so great ... CVWD hasn't gotten there yet.

Other golf courses and where they are compared to us ... I can't say without knowing the facts.  But I can say that it is apples to oranges for the reasons for our differences.  I also can say the water issues in the Coachella Valley are at critical mass and those like us who are water managers instead of water throwers will survive these issues while saving tens of thousands of dollars in water and pumping costs.  Lastly, I can say that ryegrass will not survive the summer in the Coachella Valley ... that is why we overseed instead of interseed every year.

But please still voice your concerns, we will check out any golf course, any time, any where and get the facts for the differences ... even the numerous ones that are in the Valley much worse than us right now.  If the is a better way the we can afford I will be the first to incorporate into our system.