ABSTRACT:This paper explores the occurrence of multiple critical depths in one‐dimensional computational models of open channel systems. The mathematical formulation is reviewed, including examination of the number of possible roots by Descartes' Rule. Governing equations and dependent variables are scrutinized using two compound cross sections. Occurrence tendencies are reviewed for singular channels. Critical flow is introduced as a tool to determine the existence and location of computationally based multiple critical depths. A strategy to manage multiple critical depths in existing one‐dimensional steady or unsteady models is propo