Troy...we have a similer fert program here on our course in high and dry Montana....I have no idea what 1.5" of water per week translates into...we are pumping close to 700,000 gals.per night right now (23 days this month over 90 degrees...9 days over 100..no rain at all)....our fairways are firm and fast and have lots of color...the greens however are soft....I mentioned this to the superintendent the other day and he said, "yeah,the ballmarks are getting deeper...." But he didn't dial back the run times....we have,every year,a serious problem with localized dry spot on several greens....and I think he catches hell for it every year...but I don't think increasing the run times is the answer....I would rather see us do more intensive handwatering, more timely applications of wetting agents,and perhaps some verticuting/spiking, or something other than two aerifications per season...
The thing is...we have roots that are nowhere near 30" deep....NOWHERE near that....and the trick is putting into place other maintinance practices that will, over time, get those roots deeper....it ain't all about water and fertilizer, right?