Theories and methods developed by the United States Environmental Protection Agency (US-EPA, 1985) for dilution estimates for various ambient and diffuser conditions has been coupled to a multi-port diffuser hydraulic model developed by WAMTechnology cc to facilitate the optimisation (hydraulic performance) of the diffuser with regard to the achievable dilutions, and applied to numerous outfall projects since 1995 in South Africa, Mauritius, Kenya and the Middle East and was approved for World Bank funded projects.  

The hydraulic analysis is based on the hydraulic energy balance for the complete system by comparing the specific energy between any two points in the system, taking into account all friction and fitting losses between two adjacent points. The Colebrook-White formula is applied to determine the headloss due to friction, as it correctly models the laws for smooth and rough pipes.