v2 - Culvert

v2 new feature - Culvert

A variety of barrel cross-sections can be selected including:

pipes,
rectangular box sections,
horizontal or vertical elliptical sections of pipe arch sections.

Multiple barrels can be defined but all barrels will have the same attributes.

If the inflow is described by a hydrograph completion of the design for the peak flow causes the [Route] command button to be enabled. The available storage upstream of the embankment through which the culvert passes is defined by the slope of the flood plains on either side of the channel and the slope and geometry of the channel leading to the culvert. A table is constructed with the stage, discharge and volume storage upstream of the culvert assuming that the upstream water surface is approximately horizontal. This allows the inflow hydrograph to be routed through the ponded reach with the result that the peak flow through the culvert is less than the peak of the inflow hydrograph. The design can then be updated for the reduced flow or left unchanged.

The results are displayed both graphically and in tabular form as in other flood routing commands.

If the culvert is surcharged either by a high flow rate or by a high tail-water depth it may happen that the flow is split into two components – through the culvert and over the weir formed by the embankment. In this case the weir flow is reported separately and the depth over the crest of the embankment is shown.