Alright! We're one step closer to a drip irrigation system. The high tunnel has its own water!
The Extension folks installed a "backflow protected automatic draining freezeless sanitary yard hydrant." How's that for a mouthful?
The water line to the hydrant is buried four feet deep. Come winter the hydrant must be operated at full flow, through the diverter, for a minimum of 30 seconds before and after each use to drain the hydrant and prevent freezing.
Here's the spec sheet with lots of details on our yard hydrant.