Custom Connection

Custom Connection represents a connection with user-defined cross section. 

Parameters to specify:

Length, Slope, either Manning's n or Colebrook-White Roughness, see Connections.

Upstream (US) Cover Elevation, Upstream Invert Elevation, Downstream (DS) Cover Elevation, Downstream Invert Elevation and Cross Section.

Height and Diameter/Base Width are displayed but are not editable for a closed Custom. This is because these two values are calculated from the defined Cross Section.

In an open Custom only the Diameter/Base Width is non editable. The Height is calculated based on the upstream Junction's Cover Elevation and Invert Elevation, if the Define Cross Section's max Height is bigger then the Junctions CL-IL then this Height is used instead. If the Connections Height, USCL or USIL is user defined these values are used instead.

Automatic Setting of Elevations

Where possible connection elevations are automatically set from Surface Data data, existing Stormwater Controls - SWC and existing Junctions. This is done following the rules below but can be overruled by the user. Where elevations have been overruled by the user or by the Pipe Sizing procedure the values will be shown in red to indicate they are no longer following the rules below and will not be automatically updated.

US Cover Elevation

• If the US coordinate is on a surface then set the US Cover Elevation to be the surface elevation at the US coordinate (in the case of a Stormwater Control this may be at the location of an Inlet or Outlet).
• If the US coordinate is not on a surface (either a surface is not loaded or the US coordinate is not on a surface) then set the US Cover Elevation to the Cover Elevation of the upstream Manhole or the Exceedance Elevation of the upstream Stormwater Control.

DS Cover Elevation

• If the DS coordinate is on a surface then set the DS Cover Elevation to be the surface elevation value at the DS coordinate (in the case of a Stormwater Control this may be at the location of an Inlet or Outlet).
• If the DS coordinate is not on a surface (either a surface is not loaded or the DS coordinate is not on a surface) then set the DSCL to the Cover Elevation to the Cover Elevation of the downstream Manhole or the Exceedance Elevation of the downstream Stormwater Control.