| direct-children | documentation | graph |
| WaterArea | 96 | A body which is made up predominantly of water, e.g. rivers, lakes, oceans, etc. | ^ |
| FreshWaterArea | 6 | A WaterArea whose Water is not saline, e.g. most rivers and lakes. | ^ |
| River | 3 | River is the class of large streams of fresh water flowing through land into a lake, ocean, or ot... | ^ |
| Reservoir | . | A Reservoir is an artifically made (or artifically enlarged) holding area where water is collecte... | ^ |
| Creek | . | Creek is the class of small streams of fresh water flowing through land, usually into a River. | ^ |
