Design Parameters Dialog

Specify the parameters to be applied during the design process.

Option	Description
Inflow Calculation Method	The Sewer module supports three inflow calculation methods: Unit Flow Harmon Hydrograph Select the required inflow method.
Friction Loss Formula	The Sewer module supports two friction loss formula: Manning Colebrook-White Select the required friction loss formula.
Geometric Controls
Minimum Drop Distance	Specify the minimum distance between the manhole invert level and the outlet level of an incoming culvert to apply a drop inlet in that manhole.
Flow Controls
Minimum Velocity	Culverts will be placed at a slope which will maintain the minimum flow velocity specified here or the maximum slope specified in the Link Tables, whichever is the least. In practice this results in the first (upstream) culverts being placed at the maximum link slope, typically 1 to 1.5%, and as the link flows become significant down the line the link slopes start flattening to the minimum slope specified in the Link Table. This setting will result in all links, where the velocity is less than the specified value, to be displayed in red in the results.
Maximum Velocity	This setting will result in all links where the velocity exceeds the specified value to be displayed in blue in the results.
Use minimum Full - bore velocity in calculations	If this option is selected, the velocity will be calculated with full - bore flow and not for actual flow. Normally the velocity will be calculated with the actual calculated flow. The calculated velocity will be compared to the specified Minimum Velocity.
Dynamic Inflow Update	If this option is selected, the inflow units at a node will be updated as erf connections are added to the network, deleted from the network or moved between nodes. Inflow units will also be updated if erf connections are affected by inserting, deleting, moving and changing of the connectivity of sewer nodes. This option will override all manually added inflows. The inflow units will be updated after the erf connection analysis. Connections that are flagged as Not Possible will not be accumulated into the network.
Enable Sewer and Storm Reported Link length	Check this option to use reported link lengths. If this option is selected, the reported link lengths are outputted in the screen output, results, property bar, Link Data Editor, and the Links tab of the data spreadsheet.
Use 2D or 3D length	Specify whether you want link lengths to be calculated as 2D or 3D lengths.
Use difference between Centres or Inside Edges	Specify if you want to calculate lengths using differences of centres or inside edges.
OK button	Click to accept the current entries.
Cancel button	Click to cancel the function.