When the geographical surveyors came through the area in 1864, they noticed that one particular river ran into water which was so deep that no sand bar formed at the mouth. Because there was no "bar" that river was named "Temperance."
The river's name reflects the absence of a typical sandbar, which is often associated with shallow water. The name "Temperance" may have been chosen for symbolic reasons or to reflect the calm nature of the river.