Dying blackberries

Greetings,
I’m hoping someone here will be able to provide some advice. My 3-4 year old blackberry bush produced lush blossoms in abundance but the berries dried up and fell off before ripening. I live in Zone 9–very dry. I watered about once a week over the winter and now watering almost daily watching the leaves turn brown and crunchy. I’m pretty sad since last year the bush produced so well.
Thank you

As one possiblity, research black rot. It is a fungal issue that happens in humid environments. Is your area of California experiencing a humid spell?'

Hi,
My post that I thought I wrote disappeared.  
Thank you for responding. We are in a drought here in SoCal, so the only water the blackberries receive is what I provide. Usually buckets of water from warming up the shower or dishwater. I use a grey water appropriate dish detergent. I started hand watering nearly every day in March because the bushes were looking dry.  Almost always just water the roots.