As an example, my 24 foot long greenhouse catches water on one side only and the water butts never need filling, despite being used for 30 10lt tomato tubs and around 30 5lt pepper tubs. My other greenhouse which is half the size ( again only catching on one side ) regularly overflows 4 butts and I never need the hose. I only ever use the hose to refill the butt that waters my bean row but I could manage without it.
I suspect 90% of water from a hose doesn't directly help the veg but just encourages weeds so I rarely water anything anyway.