The Hydraulic Capacity of Sewer System Scanned by CCTV Inspection

Sewer and wastewater systems suffer from insufficient capacity, construction flaws and pipe deterioration. This paper presents the results of a research developed inside the CARE-S project focused on sewer and storm water networks management. Hydraulic simulations are usually done running commercial models that apply, as input, default values of parameters that strongly influence results. Using CCTV inspections data to catalogue failures affecting pipes, a 3D model was used to evaluate their hydraulic consequences. The translation of failures effects into parameter values producing the same hydraulic conditions caused by failures was done through the comparison of laboratory experiences and 3D simulations results. A Visual Basic routine was developed in order to automatically calculate the effects of temporal decline in terms of pressure drops in the system components: coefficients of local or distributed head loss. Those parameters could be the input to 1D commercial models instead of the default values commonly inserted. This will move the results from 1D models closer to reality and decrease a number of calibrations needs. It can also be used during the operation time for changing performance capacity due to deduction of failures, or for prediction of capacity due to predicted failures on a sewer system.