http://www.specmeters.com/assets/1/7/Kieffer-Huck_Abstract2197.pdfHere is another good read if you are interested in water use on golf course.
To paraphrase it, Distribution Uniformity (DU)
[measure of how uniformly water is applied] on the surface does not always have a direct correlation to DU in the soil. Why does that matter? Because we are taught that our modern irrigation systems should have very high DU if we are to save water and grow good turf.
(85% -90%, measured on the surface rain is not 100%)My premise is while a system should have uniform spacing, excellent hydraulics, and single head control, it is not necessary to continue to chase perfect uniformity because it does not result in uniformity where you need it most, the rootzone. There is a point where the cost/benefit equation says enough is enough and going any farther does not mean "better" irrigation.
Why is this important to architecture? Because irrigation systems are the largest line item in almost any golf course development/renovation and $$$ saved on irrigation can be used for architectural work, or even result in a project actually going forward because of lower cost.
I believe that once you reach the 80%-85% in surface DU, and as long as you have singe head control, you have the tool needed to accurately apply water to your golf course. The difference in cost between a system with 82% DU and 90% DU can be upper 6 figures to low seven figures. In most cases I do not believe that cost is a good investment.