You only put heads down one side of the drive, right? The corners along with the areas that spray does not overlap will not get properly watered with this design. If you don't believe me put down cups and note the difference between the corner where the grass is weak and where the heads overlap. Or you can visually see it if you look. You may have got away with this design in milder weather but when things get hotter and drier the improper design shows. See this all the time. Dog urine may be a factor but at some point you need to address this if you want it "right" which I assume you would since you have gone through all this work.
Last edited by ArTurf; 07-24-2013 at 12:08 PM.