You can project a portal to a pocket dimension with seemingly infinite space in it. You will always know what's in the pocket universe, and you will always be able to retrieve what you want from it. The opening of the portal will increase in size when you try to insert something larger than the hole itself. The pocket dimension can hold all the water in the world, but it would take many lifetimes. You can telepathically order the portal to shoot something out at 60 miles per hour or less.