I watered a bigger garden than that by hand for years. 80" x 30". Didn't like the sprinkler because it didn't discriminate between paths and actual veggies.
You can do drip irrigation, we do now. Same as you, my OH ran a line in a trench to and along one side of the garden. That line stays in all winter and he blows it out each Fall. In the garden are removal drip lines that we pull out each Fall. We prefer to bury the drip line so it is not spraying beyond where we want it to go. There is a problem with this method in that it does make planting and bit awkward, seeds need to go close to the line. We often plant first, then bury the line when we have germination. And, any line left on the surface expands remarkably in the heat and when it does it develops waves and has wiped out rows of tender seedlings.
Oh, and when digging potatoes we have to be careful not to slice a line. Still, it works very well.