WMS:Elevation Discharge Relationship

Discharge data for the basin/reservoir can be entered either by supplying an elevation vs. discharge pairs, or by defining any number and combination of spillways (weirs), outlets (orifices), and standpipes (weir-orifice combinations). The Elevation Discharge Input dialog is used to set up the discharge data.

If the Known-Discharge option is chosen, it's necessary to enter a series of Elevation and Discharge values (it's necessary to have the same number of values in each series) to define the relationship.

If the Discharge Structures option is chosen, it is possible to add any number of weirs, outlets, and standpipes along with their individual parameters. WMS will then compute an elevation discharge relationship with an appropriate elevation step and display it in the detention basin calculator. When defining a weir the parameters can be chosen from the available weirs in the weir calculator by selecting the Weir Calculator button.

If an HY-8 Culvert coverage is defined in the map module, use the HY-8 Culvert button in the Elevation Discharge Input dialog to define an HY-8 culvert crossing. The elevation-discharge computations for this crossing are then assigned to the WMS Elevation Discharge relationship. The hydrograph is routed based on the HY-8 computed elevation-discharge relationship. One important thing to remember when using the HY-8 computed elevation discharge relationship is that HY-8 only computes headwater elevations for the range of discharges specified. Be certain to specify a range of discharges in the HY-8 analysis that corresponds to the input hydrograph discharges.

Related Topics

• Detention Basin Calculator
• Storage Capacity Curves