Monomictic

Monomictic
Lakes and reservoirs which are relatively deep, do not freeze over during winter, and undergo a single stratification and mixing cycle during the year (usually in the fall).
Source: Terms of the Environment ...

Monomictic
Lakes and reservoirs that are relatively deep, do not freeze over during winter, and undergo a single stratification and mixing cycle during the year (usually in the fall).
Montreal Protocol ...

See also: Lakes, Reservoir, Stratification, Municipal sewage, Mutagen