any sea, lake, pond, ditch, etc. (whether it contains water or not), usually marked with either yellow stakes or lines (see also "lateral water hazard") Example: The water hazard was [..]

any sea, lake, pond, ditch, etc. (whether it contains water or not), usually marked with either yellow stakes or lines

Any kind of open water source, from lakes to streams to ocean to sea or even drainage ditches on the course are termed as water hazard. Even if there is no water, let's say in a seasonal creek and the ball is dry, it is considered to be a water hazard.

An area marked as being a water source, including ditches. A golfer is not permitted to ground their club inside the water hazard if their golf ball comes to rest there.

any sea, lake, pond, ditch, etc. whether or not there is any water in it. Usually marked with either red or yellow stakes (sometimes lines) (see also "lateral hazard"). Example: & [..]

It is considered to be the worst obstacle, because the balls can only be “fished out”, and it involves a penalty kick.

A defined hazard

Water hazards are built to increase difficulty of the holes. Sometimes they are used as water reservoir to irrigate the golf course. The use of yellow markings is for water hazards in front of the gre [..]

Water hazards are usually natural obstacles that add difficulty to a golf course, though on brand new courses they can of course be man-made. A water hazard

Any body of water on the course.

A Water Haard is an area of water on the course, usually defined by yellow stakes.