I am a big fan of not skimping when it comes to irrigation pump stations/systems on golf courses. If the irrigation system doesn’t have any water because the pump system is not operational, it doesn’t matter how great the irrigation system is – irrigation does not work without a properly operating pump system. I can also install an irrigation system that can be expanded or upgraded in the future. It may not be easy, but it can be done without replacing the entire system. On the other hand, pump systems in order to be upgraded or expanded in almost all cases need to be replaced. To avoid that large expense and huge headache, just do it right from the start. What things should a modern golf course irrigation pump station include so that it will have a long life and not be obsolete one year after you install it?
First, make sure it is of sufficient capacity. The pump station flow is what determines how fast you can water the golf course (water window). Do you want to irrigate the entire facility in four, six, eight or 10 hours? Most designers recommend under eight hours. Needed capacity is just a matter of how much water the irrigation system uses a day or week divided by how many hours you allow the system to operate. Suppose a new design or your existing system uses 322,000 gallons per night and you want to irrigate in six hours. That would require a minimum pump station size of 895 gallons per minute (322,000 gallons divided by six hours divided by 60 minutes per hour). However, that capacity assumes you can use the 895 gpm flow every minute of the six hours which won’t be the case, so you need to add a safety factor and some room for the pumps wearing. Realistically it would be a 950 or 1,000 gpm pump system. That would work well in a northern climate, but let’s say your course is located in a more arid climate and the system uses 885,000 gallons per cycle in a night and you want to irrigate in six hours. Then the minimum pump station requirement is 2,459 gpm (885,000 gallons divided by six hours divided by 60 minutes per hour); realistically a 2,750 or 3,000 gpm station – bigger pump system, larger safety factor. I have been at many golf courses where run times are 12 hours or more. That’s no fun for the superintendent as it affects maintenance operations and play.
Pressure is another major component. Every golf course’s irrigation pump system requires a different operating pressure as it is based on pipe size and routing (friction losses), sprinkler operating pressure (60, 65, 80 or some other psi) and the elevation change over the golf course. Elevation change is where you see the most problems, as the elevation change was not taken properly into consideration during the design/specifying/ordering of the pump station. Remember every foot of elevation changes is 0.433 psi (2.31 feet = 1 psi) up or down.
Variable frequency drives (VFDs) are standard items on pump systems these days, but make sure your system still has one on at least the main pumps. The pressure maintenance pump may also need a VFD. Some manufacturers try and sell you a drive per main pump, but that is really only necessary under very specific circumstances. In order for a pump system to be smart, it requires logic. Programmable logic controllers (PLCs) are much smaller than they use to be, but contain lots more memory. This logic will contain all of the software/code for system operation including how the pump system integrates with the irrigation system. If your system has a filter, make sure the filter controls are integral to the pump system operating software. Standalone filter controls do a poor job of integrating with the software and you have a filter on your pump system instead of a filter as part of your pump system. The same applies to transfer pumps. They should operate automatically based on the logic contained in the pump system control panel.
Power monitoring is an additional feature available on pump systems. This feature is not for every course, but where power is expensive and there are times of use load restrictions on the power supply it is worth the money.
Probably the biggest improvement in pump stations is monitoring. Today, monitoring is mostly Internet-based and allows you to monitor operation and controls from anywhere you can use a smart device. In addition to the normal flow and pressure readouts and what pumps are on or off, new monitoring provides pond levels, wet well levels, power use and which pump operated when along a timeline. Pay attention to what each manufacturer can provide in terms of monitoring and integration with the irrigation system controls as there are differences.