Golf Engineering Associates Technical Help Series

Do you really need an irrigation designer?

Irrigation is one of the most expensive and complex parts of any golf course construction or renovation project. Adding heads or re-working portions of a course is routine for most superintendents, but if the project approaches or exceeds $100,000 you should probably seek outside advice. Managers and superintendents should consider the following:

• Who is financially responsible or legally liable if the system doesn't work?
• Can you maintain the golf course as usual and undertake a major project?
• Does your workman's compensation, general liability and other insurance cover you for major construction projects?
• Are you getting the best design, materials and prices by doing it yourself?

If you have any doubts about these issues, consider hiring design professionals such as Golf Engineering Associates, Inc.,  or qualified irrigation contractors to guide you through the process.

How Much Coverage - How Many Heads?

The answer to the coverage question relies on two main factors:  a) climate/region,  and b) what level of golf play does the course support. High profile courses, country clubs and venues for PGA events undoubtedly will want "full coverage", a term synonymous with complete irrigation of all turf areas. This is also the case in arid regions such as the Southwest and Southern California. Even in wet climates the expectations of upscale daily fee and private club members will demand full coverage. This means that all greens, tees, fairways, roughs and some out-of-bounds will be irrigated head to head. In other words, if the sprinklers planned for your course throw 70 feet you will be spacing heads a maximum of 70 feet apart in a continuous swath from tee to green.

Never make the mistake of spacing heads beyond their maximum radius as listed in each manufacturer's literature. Stretching your sprinkler spacing is the absolute worst way to save a few bucks; besides, there's plenty of other ways to save money on an irrigation install. Instead of stretching spacing, try to eliminate unnecessary irrigated areas, irrigated out-of-bounds, etc.

The green complex is the heart of any golf hole, so you should never try to economize there. This diagram shows triple-row irrigation coming up a fairway towards a fully irrigated green complex. The part circles around the green complex are necessary to water bunker faces, mounds and any other features around the green. Overall, it is less expensive to install a triple-row system with lower radius-flow heads than a double row with larger turf rotors because the swing joints, lateral piping, valves and miscellaneous fittings can be sized smaller. The big rotors throwing 95 feet (or more) and putting out 60 gallons per minute are going to get you into 1.5" swing joints, 3" lateral pipe, etc., and certainly will not water as effectively as the triple row with 60 to 70 feet spacings. One exception are those courses going with single-row systems. When installing a single row system you might as well get the biggest head you can and blast them wide open. Run your 4" or larger mainlines right up the middle with taps coming off at each head.

Golf Design Tips

Coverage and even sprinkler spacing is the number one rule. If you get into a situation where spacings are 70, 70, 70, 70 with a 100 foot at the end, you should ADD another sprinkler and evenly space them at 63-64 feet instead of spreading them out. In our opinion, you should never space a sprinkler at it's maximum throw anyway, meaning that if a sprinkler nozzle is listed at 70' radius, we would normally space them at 67-68 feet maximum. If the site has prevailing winds, or is windy in general, that same 70' sprinkler might be spaced normally at 62-65 feet. Other design tips are too numerous to mention, so we have highlighted our favorites at right.

Saving Water, Energy, Time and Money

With existing courses we recommend that if the annual repair budget for irrigation and pumps exceeds 10% of the overall maintenance budget, it's time for a renovation. Golf Engineering Associates, an international irrigation consulting firm, reports an average savings of $2000 per hole per year on older, full-coverage courses once they renovated. The main savings comes about through a drastic reduction in both time and money for repairs. This figure also includes a savings in water use, pump run time, electricity and other factors. A fringe benefit is the fact that your crew will have much more time to mow, rake traps and attend to details that you never thought possible because they're not down in a ditch fixing irrigation problems all the time.

When planning the irrigation for a new golf course, the absolute number one way to save money is to decrease the amount of irrigated turf. An average cost of installing irrigation today is about $675 per head, which would include design, installation, controllers, parts, wiring, etc., plus an average of about $100,000 for a complete pump station. At 63 foot triangular spacings (our favorite) you will require approximately 15 sprinklers per acre. Add it up: if the course is 100 acres the cost will be somewhere around $1,000,000; decrease the turf acreage to 90 acres and the cost will be around $910,000. Example: The diagram at left shows isolated tees surrounded by either desert landscape or native grasses which don't require irrigation. The turf area is limited to the tee tops, and the installation cost is roughly 2/3 of what it would be if full circle valve-in-heads were watering the whole area. This kind of careful limitation of turf areas has many other advantages such as water savings, less pumping time and less maintenance. The second best way to save money is by eliminating non-essential items from the irrigation system such as premium central computer software, weather stations, pump station whistles-and-bells, non-vital specialty valves, etc.

Saving water is simple: your new, advanced control system will give the superintendent the ability to water with precision throughout the golf course. If some areas get too much, turn heads down station-by-station. If some areas are too dry, turn them up at that one spot. Every major manufacturer has water budgeting features in their control software packages, even the lower end products. An overall water use savings of 10% with a new computerized system (programmed for optimized performance) is a very conservative estimate. Nothing else needs to be said: you're going to save a ton of water with a modern efficient irrigation system.