In this picture, irrigation water is definitely not being supplied wisely. The row of rotors along the road are watering not only the strip of grass and trees and shrubbery, but also the street, the sidewalk, and some of the cars in the parking lot on the right.  It would appear that maybe 50% of the applied water is wasted.  If each rotor uses 4 gallons per minute and is run for one hour per day, 3 days per week, 720 gallons of water are sprayed and 360 gallons are wasted per week per head.  If this landscaped area contained ten rotors (a fairly small system), 3600 gallons of valuable water per week. At $3.45 per one thousand gallons (a local rate), that would be $12.42 per week literally being poured down the drain.
This example of poor system design can be improved greatly without additional piping and trenches. The rotors can be replaced with sprayheads with special nozzles to cover just the strip along the road.  The shrubbery on the other side of the parking lot could be irrigated using micro- or drip-irrigation.  Call a professional irrigation installers for assistance in irrigating wisely.