The following is a short article published by Pace Turf, a science-based advice and information service for the turf management community. 

Managing in a drought emergency

Saturday, January 25, 2014

How prepared are you, with both a philosophy and a strategy, for dealing with drought if or when it hits at your location? We have a few ideas that will hopefully be of assistance.

With the lowest rainfall in over 100 years, extreme drought has now spread through most of California, leading California's Governor Brown to declare a drought emergency this week. California may represent the biggest single area of drought, but extreme drought is also indicated in pockets throughout the Southwestern U.S., while conditions ranging from abnormally dry to severe drought exist through most of western half of the country. Read more here about how scientists are weighing in on the severity of this drought.

Even in areas of the world where rainfall is heavier, a droughty month or season can strike at any time. Here are some strategies for you to consider.

Where can you cut? There are two major approaches to reducing water usage:

1. maintaining turf acreage at current levels and making across the board cutbacks in irrigation volume so that all turf receives 10 to 20 percent less water
2. reducing the turf acreage by 10 to 20 percent, and maintaining the current level of water usage per acre

In most cases, we believe that option 2 is the most agronomically sound and also, in the long-term, one that golfers and managers will appreciate the most as well. This is based on our observation that most irrigation systems are already tuned up to the max, with little wiggle-room to reduce irrigation volumes without causing big losses in turf quality and playability. In other words, if you could have cut back 10 - 20 percent and maintain turf performance, you would have already done so. For golf courses that face the demand to reduce water use by 10 to 20 percent, there is really only one option, albeit a painful one. Turn the water off, and abandon turf in selected areas of the course.
Identifying water reduction goals: As a rough guide, calculate the number of heads that need to be turned off to reduce your water usage by 10%, 15% and 20%. For example, if you have 3,000 heads on your course, you will need to turn 300 heads off to meet 10% reduction, 450 heads to meet 15% reduction and 600 heads to reach 20% reduction.
Turning the water off— in stages: Before implementing each stage below, write an irrigation controller program that calculates the water savings generated during a normal irrigation run when the specified heads are turned off. Label each program with a description of the areas that will not be irrigated (for example, "out_of_play_off" for the Stage 1 program below, or "under_rough" for the Stage 2 program).

• Stage 1: Abandon out of play areas (primarily aesthetic impact).
• Stage 2: Abandon under-utilized rough areas (primarily aesthetic impact, some impact on high-handicap golfers).
• Stage 3: Abandon non-landing areas in fairways and rough (heavy aesthetic impact, impact on high and mid-handicap golfers). With cooperation of the greens committee and membership identify primary landing area that is used by most golfers and maintain irrigation in those locations only.
• Stage 4: If the above three steps do not produce sufficient water use reductions, government restrictions will probably be extremely limiting. Extreme drought has resulted, in some cases, with only greens being irrigated. In this situation, the government has essentially taken irrigation management out of your hands.

Useful Resources:

• A simple irrigation audit that you can do on your own is described in detail in the PACE Update, "Shoe box irrigation audit"
• Challenges in achieving irrigation efficiency are described in this PACE Turf Insights, "Issues in irrigation: the uniformity myth", and this PACE Update, "What you see is not necessarilly what you get: check your irrigation system output to avoid drought.
• The U.S. Drought Monitor, mentioned above, provides several useful resources on the website, include drought maps (by region and state), an archive of drought data that goes back to the year 2000.
• The North American Drought Monitor provides similar, though less detailed, information for the U.S., Canada and Mexico.
• The Drought Impact Reporter, provided by the University of Nebraska, tracks the specific impacts that drought has had, county by county, all around the U.S.