When do you need an irrigation designer

Posted by Craig Zellers

images 4By Gary Kaye & Craig Zellers

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

  • Who is financially responsible or legally liable if the system doesn’t work as intended?
  • Can the golf course be maintained as usual and can staff undertake a major project?
  • What affect will the changes have on your budget and turf conditions?
  • Can the pumps and hydraulic system handle the changes?
  • Will your central programming and hydraulic zones need to be adjusted?
  • Does your workers compensation, general liability or other insurance cover the course for major construction, design and installation?
  • Are you getting the most efficient design, specifying the right materials and getting the best prices by doing it yourself?
  • Is a long term master plan for course renovation and irrigation changes needed?

If you have any doubts about any irrigation or other “Do It Yourself” project after considering these questions, hiring a design professional or a proven golf irrigation contractor to help guide you through the process may not be a bad investment. On many projects where irrigation systems were amended, we find sprinkler coverage and spacing that is no longer consistent with head to head coverage.  Even if only one sprinkler is moved, coverage and distribution uniformity can change for the worse.  When the subject of GPS base mapping and project planning come up, we always advise that a plan, (even a simple one) be set in place. This plan can be used for review, amendments and approval by all principals involved in the outcome. It can be as simple as a large hand drawn map displayed on a table top for membership or owners to review.  One golf course owner we worked with invited all members to the clubhouse for a wine and appetizers event. They were provided the opportunity to have a look and a say regarding some turf removal and the newly proposed irrigated turf areas.  “Buy-in by all” is the key to a successful outcome for any project undertaking.

Should the project be small in nature and performed in house, consider the following questions to help guide the process to a successful outcome.

Do I Need a Budget?

Establishing a project budget is the first priority.  The budget should be reviewed and approved by all principals involved.  The budget is not something you want to take a wild guess at.  You will need to do a lot of research on materials, installation costs and permits if needed.  Once you think you have established a budget, add 10% for the unknown.  It is rare to find a control system project where we don’t run into the unexpected. With surprises come extra time and or materials.  If you have hired a contractor, those unforeseen costs should have been included as part of the job.  But if you are doing it yourself, having to go to ownership to ask for more money is always a difficult task.

How Much Coverage & What Sprinkler Spacing?

The answer to the coverage question depends upon two main factors: (a) climate/ region and (b) what level of golf play does the course rely upon for revenue. High profile courses, private clubs and venues for PGA events undoubtedly will want “full coverage”. This term is synonymous with complete irrigation of all turf areas.  Given the recent drought and water restrictions, this can still be achieved with turf removal projects and more precise irrigation design.  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 and in-play rough areas be irrigated consistently with head to head coverage.  So if you are planning on 65’ foot spacing, all sprinklers must be spaced a maximum of 65’ apart in a continuous swath from tee to green.  If a turf removal project is included spacing may change if the tees only are irrigated and the area surrounding the tee is mulch or drip landscape.  Many courses have already removed the typical high gallon part/full-circle sprinklers originally installed on the tees. They have been replaced by an electric valve with short range low gallon sprinklers.  Remember, if the members or owners expect to see turf around the tees, prior approval, via the plan, should have already been in place.

Never make the mistake of spacing heads beyond their maximum radius as listed in each manufacturer’s specifications. Stretching your sprinkler spacing beyond specifications is one of the worst ways to save money on a large irrigation project.  Some of the best ways to save dollars include:

Eliminate out of play areas or double up part circle sprinklers on turf perimeters to decrease wiring and satellite costs.  

The green complex is the heart of any golf hole so you should never try to economize there. Overall it is less expensive to install a triple row system with lower radius flow heads than a double row with larger turf rotors. This is due to the simple fact that your swing joints, lateral piping, fittings and valves can all be sized smaller at a lower cost.  In addition; sprinklers with a radius of 80’ plus will not provide you the ability to effectively irrigate when compared to sprinklers spaced at 60-70’.

Coverage and even sprinkler spacing is the number one rule to follow. If you get into a situation where spacing is 68’, 68’ , 68’, 68’ with 100’ left at the end, you should add another sprinkler and evenly space them at 62-64’ instead of spacing them out further.  It is our opinion that you should never space a sprinkler at its’ maximum throw anyway, meaning that if a sprinkler is listed at 70’ foot radius, you would not want to exceed 67-68’ spacing. If the site is typically windy during the nightly cycle, you would want to space that same 70’ sprinkler at 62-65 feet.

Hydraulics (Pump Station & Piping)

With all irrigation projects consideration for the effect on the hydraulics including pump station and piping should be a priority.  Many of the irrigation systems designed in the 80’s or 90’s were done to accommodate only what was going to be irrigated at that point in time. Adding sprinklers or valves for additional turf and landscape were never a part of the equation regarding total water use. Many systems today are being retrofitted with sprinkler additions or deletions due to new housing property line issues. To drive this point home, it is most likely that 50% of the Superintendents reading this have a stand-alone satellite located at the clubhouse and it is not controlled by the irrigation central.  One current golf course client utilizes an additional 40,000 gallons at night due to additional sprinklers having been installed along the property lines.  Changes such as these have a direct impact on the pump system and the hydraulic piping. If the pump station was designed for 2,000 Gallons per minute (GPM) and an eight hour watering window, the system must now keep up with higher demand. Extending the water window is one option to alleviate over demand of the pumps. Planning for higher water flow rates and the speed of water through the pipe should be calculated because you never want to exceed the original hydraulic design parameters.  When these parameters are exceeded, expect pipe and fitting failures to occur much more frequently on an older system.

Central Programming & Hydraulic Zones

Even if you are considering a small irrigation project, remember to make the sprinkler/valve changes in the central database.  Additional sprinklers or GPM changes on the course should all be changed in the central. If this was done on every project we encounter, there would be no need to discuss this important item.  In reality over the course of time small changes such as switching nozzles or internal assemblies can have a substantial impact on the efficiency of the irrigation system.  Most often these changes lead to higher water demand that exceeds what the central is projecting to run.  The hydraulic flow zones / tree need to be as accurate as possible to avoid too many sprinklers running at the same time on main and lateral lines.  When these types of changes are not made there is excessive demand and that can lead to low pressures during the night. Additionally, water usage records may not be reliable if you only look at the central flow and not flow meters.  The hydraulic flow zones/tree is the most important regulator of water flow across the golf course during an irrigation cycle.  With proper hydraulic programming, flows will not exceed design parameters and adequate system pressure will be maintained during the cycle. This alone can help alleviate wet and dry areas, thereby making playing conditions more consistent from tee to green.

If you have any questions or need advice on any small to large irrigation project, call Golf Irrigation Consultants at (415) 342-1030