Shui Xiang, also called Water Image, is on the Kidney channel, level with the apex of the medial malleolus. This point overlaps with Kidney 3 and is used in conjunction with Shui Jing and Shui Xian.
To locate this point, find the hiatus of the medial malleolus and move posteriorly until you find the depression between the bone and the Achilles tendon.