Overflow routes

Overflow routes

These are surface paths along which overflows from pits travel. Commonly they will be along street gutters and designated flow paths, but they may run through properties and areas such as car parks. (Surface flows from sub-catchments draining to pits are dealt with in sub-catchment flow calculations. They may be combined with overflows using a procedure related to the percentage of a sub-catchment through which an overflow route runs.)

In Lite hydraulic model runs, a fixed travel time is used to translate hydrographs. In the Full Unsteady hydraulic model, the full unsteady flow solution is used in overflow routes. Therefore, invert levels are required.  Water level profiles are calculated along overflow routes at each time step.

In all cases you must select a cross-section from the Overflow route data base.

Overflow routes can be divided into segments with different characteristics (slopes, cross-sections, roughness, invert levels). The segments are separated by nodes, as shown below:

When using storage routing models, DRAINS can perform routing calculations along the stream routing reaches.

Following a run, peak flowrates are presented in the Main Window. If multiple storms are used, the results for a particular storm can be selected using the pull-down menu that appears in the top-left corner of the drawing area. The Customise Text option in the View menu allows you to vary the on-screen display.

Flows along overflow routes can be examined using the Pop-Up (right mouse button) menu that provides options for plotting flowrates calculated during a run, or for displaying the numerical values.