The surcharge section is given as a guide only to possible areas that may give problems when the design storm is exceeded. No allowance s made for increased hydraulic gradient due to surcharged manholes or backing upstream of the section under investigation.
The surcharge screen grab (grey) below is similar to the full data output screen for sizing, except that it shows the surcharge of each section both as a percentage of the pipefull capacity, and as litres/sec.
The black screen shows the output for the 2 hour loading of a system - the stars indicate that the section is surcharged - each dash or star represents 1 minute of the storm
Other surcharge options include sectional views of the system, and a plan view of the whole system. Each of these is run in time increments, and the surcharged sections are shown in a different colour to the pipe runs.