ABSTRACT
In urban catchments, the topology of the sewer network, diameters, lengths, and slopes of sewers have a key impact on the variability of flows in storm and combined sewer networks. This chapter discusses methods for calculating hydraulic flow parameters in a sewer system under conditions of steady and unsteady flow. With regard to steady-state flow, the theoretical basis for calculating flow rates in sewers is discussed using the Chezy–Manning and Colebrook–White models as examples. Attention was focused on the aspects of determining the capacity in channels with deposited sediments and the variability of their linear resistance circuit. In this connection, a novel application of the averaged linear resistance coefficient method for calculating the variability of perimeter resistance and velocity field is presented. With regard to stormwater drainage systems, the basic models for the calculation of the wastewater surface (Bernoulli’s equations) are presented. Numerical methods for calculating wastewater flow in sewer pipes based on numerical schemes (explicit and implicit) and their solution procedures are presented and discussed.
