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Constructed Waterway Designer

Products > PC- Convey > Guided Tour

The CWD uses the following terms:

  • The Low Flow Channel (LFC) is the part of the cross-section that carries the low flow (typically a 3 month or 4EY flow)
  • The High Flow Channel (HFC) carries a higher flow (typically a 1% Annual Exceedance Probability flow) plus an allowance for freeboard.

Features of the Constructed Waterway Designer:

  • From V12.10B it is possible to set default batter slopes that are used when a new CWD XS is commenced.

  • Because in reality the LFC can have a flatter grade than the HFC (due to sinuosity of the LFC within the HFC) the CWD can use one grade for the LFC and another for the HFC, within the same cross-section.

  • The CWD uses the LFC grade to determine the dimensions required for the LFC to carry its required discharge (e.g. a 3 month or 1 year discharge) and then uses the HFC grade to determine the dimensions required for the HFC to carry its discharge (e.g. a discharge having an Annual Exceedance Probability of 1%).

  • The shear stresses on the cross-section can be checked from the Constructed Waterways Designer, and if they are too high, new batter slopes, bench widths etc. can be tried.

  • The total width of the cross-section can be checked so that you know whether the current design fits in the available space.

  • The freeboard can be varied (normally either 600mm or 300mm).

  • Each Segment of the cross-section can have its own Manning's n value.

Once the input data has been entered you can check the shear stresses from the CWD screen (see next page) then return to this screen to make any adjustments necessary.

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