Thanks, Susan and Karen.
When I redid the front yard, I raised some of the sprinkler heads but did not revamp the existing sprinkler system. Because of that, I had to plant low-lying plants in the front so that the water can reach the plants in the back.
Some perennials I used was this low growing geranium and Cerastium tomentosum (snow in summer) - both blooming over long periods of time
a longer shot with Centaurea gymnocarpa "Velvet Centaurea" in the rear and yellow Bulbine frutescens to the left