There are a couple reasons for which you may see maintenance personnel watering greens by hand during your round of golf. 1) Soil moisture - Although great effort goes into the design of automated irrigation systems, even the most sophisticated systems cannot apply water evenly to all areas of the green, nor does every area of the green require the same amount of water. Putting greens are oddly shaped and often constructed with surface contours. Greenside bunkers may interfere with placement of irrigation heads around greens and wind can also adversely impact irrigation coverage uniformity. In short, no automatic irrigation system can account for all of these irregularities and challenges. Hand watering is the best way to accurately supplement overhead irrigation to areas in need of more water during the day without overwatering areas that don’t. All turf managers recognize that too much water is far more detrimental to turf health than too little so it makes sense to error on the side of dryness. It is much wiser to add a little more water the next day with the hose than to overwater the night before. 2) Syringing – Syringing is the application of very small amounts of water to the turf. The goal is to wet the leaf surface and not the soil. It may fulfill several objectives, such as removing dew or frost, but primarily syringing is performed to prevent or correct a leaf water deficit, i.e., wilt, or cool the turf canopy via evaporation (compare to the cooling effect when sweat evaporates from a golfer’s skin). During severe heat stress or periods of rapid water loss (usually low relative humidity and windy conditions), syringing may be necessary multiple times throughout the day. So when you see manual watering, how do you know for which purpose it is being performed? If the maintenance worker is pointing the hose downward toward the green, then water is being added to the soil as a supplement to the overhead irrigation system. For syringing, the hose will be pointed slightly upward so that a light amount of water will accumulate on the turf foliage only. In either case, should you encounter staff manually watering greens during your round of golf, it is best to wait patiently for them to finish. After all, turf survival likely depends on it.