By the middle of June the west end's lawns begin to ask for water, quietly at first, in pale patches near the driveway apron. Ayala's Irrigation answers with the small, exact work: finding the leak under a soft wet spot, swapping a head that lost its pattern, setting run times that match the way this stretch of the city dries. Lawn care rides along with it, so the growth the water buys actually looks like something — mowing, trimming, a clean edge. Evenings, the zones tick on street after street and the air over New Bedford turns cool and green-smelling. It is a satisfying kind of engineering: hidden underground, obvious on top.