Family: Agamidae Adult Size: The Chinese water dragon is a large lizard that can reach a length of 36 inches. Range: Eastern Thailand, Indochina and . Care of The Chinese Water Dragon. Index: Adult water dragons are, of course, green with colours ranging from a dark forest green to a light mint green. Water dragons need large enclosures, a minimum size for an adult dragon is six feet long, two or three feet deep, and five or six feet tall. An enclosure of this size will likely need to be custom made and is going to be costly.