N. fasciata is natively found from southern Illinois, south to Louisiana, and east to North Carolina and Florida.

[6] In 1992, its congener Nerodia sipedon (northern or common water snake) and it were found in three sites in California by the US Fish and Wildlife Service (USFWS).

In 2009, more than 300 banded water snakes were caught in suburbs of Los Angeles by the Nerodia Working Group of USFWS.

Further trapping did indeed catch large numbers of them, indicating that a thriving invasive population exists in that area.

Banded water snakes may also be identified by a dark stripe which extends from the eye to the angle of the jaw.

[citation needed] This species also exhibits sexual dimorphism in which the female is generally longer and heavier than the male.

[21] When threatened, banded water snakes flatten their bodies to appear larger and emit a foul musk from their anal glands, and bite repeatedly.