In recent years, the FHWA has defined an updated procedure for computing loss through a larger junction or access hole. Bentley provides the ability to switch between the previous the junction loss methods: HEC-22 Energy (Second Edition) and the newer HEC-22 Energy (Third Edition). Also detailed in the FHWA's Urban Drainage Design Manual - Hydraulic Engineering Circular No. 22, Third Edition, 2009) is equation for modeling junction loss for a junction between a smaller lateral pipe and larger carrier pipe.

Computationally, the minor loss equation is based on conservation of momentum as a lateral inflow enters the piped network. The HEC-22 Equation (7-10) is iteratively solved due to the interdependency of hydraulic grades and velocities at each boundary of the junction.