Nerodia harteri is found only in Central Texas in the Brazos River system.

[2] The preferred habitat of N. harteri is rocky areas along the Brazos River.

[2] Due to its limited range, N. harteri is considered to be a near-threatened species in Texas.

The specific name or epithet, harteri, is in honor of American amateur herpetologist Philip Harter, who collected the first specimen in Palo Pinto County in 1936.

[3][4] The Brazos water snake grows to a total length (including tail) of 16 to 32 inches (41–81 cm), and ranges in color from brown to olive green.