The sharp end of a pick is for breaking rock, not digging water lines. A chisel tip cuts the earth and also helps remove it from the trench. A point tip doesn't clean out the trench as well. To lay a water line, you want to dig a trench of minimum width in order to save labor. The wide blade end of the pick is good for digging trenches, but it is way overkill for a 1/2" water line.
To solve the problem I made a removable tip cap for the pointed end. It was just a piece of pipe that I hammered onto the pointed end of the pick, forcing it to conform to the square shape of the pick end. What protruded past the tip was then flattened with hammer and anvil to make the chisel shape. I had welding capability in those days, so I welded the seam at the end , which allowed sharpening with a grinder.
It easily taps off when you need the point of the pick, and taps back on when you need the chisel tip.
It works great, and has saved me some sweat over the years.