Shouldn’t all irrigated lawns be green? Yes and no. Take the pictures above. The picture on the left is the entire lawn and the picture on the right is a small piece of the same lawn. This is typical of almost all lawns, especially those with established trees. 
In a perfect world, irrigation would provide a 100% green. The problem is that different parts of a lawn have different soil profiles and water needs. Gravel buried under the soil, tree roots, slopes, and reflected sun and shade can all vary the irrigation need and create wet and dry spots on the same lawn with the same irrigation program. Adjusting the sprinklers can help but often times, it is unavoidable.
Historically, we watered more to compensate for those hard to water areas. As water costs have increased, we have worked to lower irrigation to save our customers money. The bad news is that the result are a few dry spots on most properties. The good news is that allowing a few dry spots can reduce water costs 20-40%. This is where Weather based irrigation come into play. Weather based irrigation replaces the water lost based on weather. If a tree is competing for water in a lawn, that shows up. To avoid wasting water to overcompensate for this, we are recommending that the difficult to irrigate lawn areas be replaced with rock or ground cover. If it is hard and expensive to water, change the landscape.