Water gardens, also known as aquatic gardens, are a type of man-made water feature. A water garden is defined as any interior or exterior landscape or architectural element whose primarily purpose is to house, display, or propagate a particular species or variety of aquatic plant. Although a water garden's primary focus is on plants, they will sometimes also house ornamental fish, in which case the feature will be a fish pond.
Although water gardens can be almost any size or depth, they are typically small and relatively shallow, generally less than twenty inches in depth. This is because most aquatic plants are depth sensitive and require a specific water depth in order to thrive. The particular species inhabiting each water garden will ultimately determine the actual surface area and depth required.