Crop circles of the golf kind

The 2012 golf season is off to a dry start. Every golf course in the area is experiencing the same challenges. All inadequacies in the irrigation system show up very nicely. The trick is finding the problem and having a solution.
Here is one example.
Dry area 6 feet in diameter around sprinkler head.
Watching the spray pattern indicates a faulty short range nozzle.
Inspection reveals a worn tip on the short range nozzle, shown in the photo on the furthest left nozzle. Compare a newer short range nozzle on the assembly on the right.
One down, a thousand more heads to go!
Turf