Golf Course Irrigation

In recent weeks, I have been asked by several members if we have cut back on our watering this summer. In this blog, I will discuss the weather data, irrigation infrastructure, water quality and staffing. It is like a multiple choice question on a exam and the answer is: (D) All of the above. Golf course irrigation systems are a supplement to Mother Nature’s rainfall. The best designed systems are not capable of matching rainfall’s efficiency and/or water quality. Here in Northern California, we are in a Mediterranean climate where we do not see rainfall from mid-May to mid-October, so irrigation infrastructure, water quality, and staffing are critical to get us through those months.

As many of you know, we received only 60% of our average rainfall this winter season. Normally, we have around 28 inches in an average year. This past season we only received 17.7 inches with the majority of that in December and January (12.01″). In February we received no rain, March 1.35 inches, April 1.03 inches, and May 1.49 inches. Since we are in an arid region of the country during the summer months, it is more important how far into the spring we receive rainfall, other than how much, so the lack of rain late in the spring season, aging irrigation infrastructure, water quality and staff reduction due to the pandemic created a perfect storm for the dry conditions you are seeing this summer. With that being said, we have always had to manage those issues on this property even during my tenure here back in 2005 – 2006. Staffing is critical to supplement the inefficiencies until a solution can come to fruition.

As I stated above, the irrigation infrastructure is an aging system. The pipe, valves, and partial wiring in the ground are over 30 years old. The electronic controls, heads, and the remainder of the wiring are 17 years old. It is definitely time for some upgrades and possible replacement due to the existing pipe size. I am actually meeting with the two leading irrigation companies this week to get the discussion started and begin to come up with some numbers and hopefully solutions for the future.

Another part of the equation is we rely on well water for our water source during the summer months. This can also be challenging due to the salt concentration levels. A lot of the wilt you see in the afternoon on this property is salt related. A good example of what salts do to the plant is having a glass of iced tea on a napkin and the napkin sticks to the bottom of the glass when you lift it up. Pour some salt on the napkin, which absorbs the moisture, and the napkin will not stick to the glass. The same thing is happening in the soil environment creating a situation where you get salt induced afternoon wilt, especially on warm days. Another factor is we only pull approximately 600 GPM from the wells collectively. Along with that, our irrigation pond has a low holding capacity due to all the silt runoff from the Sonoma Mountain range to our west creating a situation where we have be judicious with our watering programs.

Along with those issues, we have seen an increase in the fungal disease Southern Blight on our fairways and rough this year due to the hot weather and irrigation coverage. Southern Blight has been an issue here at Sonoma Golf Club for many years. In the past we have mapped the problem areas and spot treated. Due to the increase of incidence over the years, we plan to budget for preventative applications in all our fairways and one pass around them in the rough beginning next year. We will continue to map and spot spray outside those areas.

Hopefully this information will enlighten everyone on some of the issues we are dealing with this season and to let you know we are planning solutions to not only recover from this year but to mediate the severity in the future.

Yours in turf,

Stacy L. Wallace, Golf Course Superintendent