Sam,
Here in TX, you might have seen the commericals for
http://www.savetarrantwater.com/Pages/OutdoorWateringTips.aspxIn general, the supers are right here. For every region of the country there is daily Evapotranspiration. Each type of grass responds differently, with warm season grasses using less of what is called "pan ET" than cool season grasses (about 60% to 80%). Every soil has its own water capacity (measured in inches, and often around 3") Most turf dies or goes dormant when it has less than 33% of its moisture capacity filled.
Supers in some areas can choose turf for drought tolerance (bermuda vs bent greens in the south, for example) and save 25% of water right off the bat. They can aerate tight soils to let more moisture in.
However, for the most part, the plants need what the plants need. We seem to be finding that moisture sensors in the soil give us a better take on how dry the turf is, and its often less than the recorded ET, which makes sense, because water doesn't evaporate out of the soil as fast as it does for the surface. So, in that sense, some guys have been overwatering when they say they simply replace ET every night. (typically .10-.25" per night, depending on region) They might be able to get by with less, or water every other or third night in most areas.
The only other thing they can do is plan or take a bit of a chance on replacing less than ET (or actual soil moisture from the sensor) and hoping a weekly rain makes up the difference before the turf hits the drought or death point. And, they can replace less than ET because the turf doesn't need to be at full field capacity, it can be as low as 33% and easily 50% in most cases (except maybe for greens) rather than 100% and do nicely. However, at some point, reduced water gets turf down to danger levels of moisture, and if close to the edge, at that point, the super must water to full ET at night, or risk losing the grass.
Short version, managing for medium dry conditions is not an exact science! I really don't know any supers who overwater, i.e. put 110% of ET on. I know many who do replace ETat 100% each night, and still others who don't have the turn off features that stop the system if rain starts. For most, several times a summer they face the question of "Do I water tonight if there is a 60% chance of rain?" If turf is dry and they don't water, they might be in trouble, but if they do water, and it rains, they are wasting it. What should he do? Given they get up every morning at 4:30, I can see them staying in bed at 1AM, knowing they "should" go in and turn off the sprinklers.
And, most have antiquated irrigation systems that were designed mostly to throw as much water as possible, not conserve it.
Such is the reaons I started this post. While every region is different, the amount of water wasted by the typical homeowner probably far outweighs what is lost by intelligent superintendents over watering their golf course.
For that matter, Pat has brought up this issue several times. I can tell you I haven't played a truly soggy course in several years. (I do find isolated wet areas that I believe the super could adjust sprinklers for, though) For that reason, I wonder if this is somewhat of a myth of gca.com that modern supers aren't very knowledgable while golfers could easily do their jobs?