I've been growing new trees since 2012 on my 2 acre lot near the devil's backbone. The soil is generally quite sandy, so top watering will work down. I only have drip irrigation and my trees have grown quickly. The bigger problem can be a dry winter, with little snow in the foothills. I nearly always apply some water, once a month to my trees and bluegrass if it's dry. Watering the pasture grass in the winter is not practical and I do get some winter kill as a result.
I'm fortunate to have ditch water irrigation, so I can keep my whole lot green in the summer, until the ditch quits running. After that, I have to use city water and limit my watering to trees and maybe 8000 square feet of blue grass.
