Roses are thirsty. Like all living things, they need water to survive. The way in which you water your roses and how much you water them, makes a big difference in how they thrive and grow.
In general, most modern roses require at least 1″ of water per week to thrive. I watch the weather and observe local rainfall totals. If it rains one week, I skip my “intervention” watering regimen. If it does not rain that week, I carefully water my roses. The water that falls from the sky is far superior than the hose water I use.
When watering my roses, I always water at the base of the plant. I never spray the shrub and wet the leaves. This invites disease. If you must spray water your roses, do so in the early morning so the sun will dry the bush before noon.
Ideally, an irrigation system should be employed to water your roses. Many of these systems, are costly to install and maintain. For these reasons, I do not have an irrigation system. I water by hand. It is a time consuming process, but well worth the effort.