I don't encounter hawks too often, but a year or two ago, There was one parked high up in a tree in the back yard. My chickens were hiding under bushes in same backyard.
I started yelling, and making all kind of noise. No reaction from hawk. Hawk knew it was safe out of reach up high.
Also considerably higher than what my water hose could spray.
So my plan B, went into effect. Went to garage, and lit a firecracker, and threw onto driveway. Hawk was gone like the wind.

This was one of the small size firecrackers,, Not the LARGE/LOUD style like Cherry Bomb, or M80.