That is normal symptoms for not watering enough, but they've been getting plenty of rain there...so I don't think that is the issue. I've just found out the roses have been planted for several years too...so they are established.
I've had that happen when my solenoid on my drip irrigation system went out. I hate it when that happens. So now I just replace the solenoid's once per year, in the spring, to reduce the risk of that happening. Solenoid are cheap.
Alan
