Stormwater pumps are used in situations where gravity drainage is either impossible or impractical. Stormwater pumping is expensive to operate and maintain and poses several potential problems that must be addressed. Therefore, stormwater pumping should only be considered when no other practicable alternatives are available. Alternatives to stormwater pumps include siphons, recharge basins, deep and long storm drain systems, and tunnels.
The following situations require the use of stormwater pumps:
- To lift stormwater to a higher elevation when the discharge point for the local collection system lies below the regional conveyance.
- To lift stormwater to a higher elevation when terrain or man-made obstacles do not permit gravity flow to the discharge point. For example, a roadway underpass at a railroad crossing.
This article describes how to use the Pump Outflow panel of the Storage Area Data dialog box to define the pump outflow parameters for the storage area. Refer to this article in our knowledge base to learn more about the Storage Area Data dialog box.
Follow the steps below to use the Pump Outflow panel:
- In the Storage Area Data dialog box, select Pump Outflow from the Storage Area Specifications dropdown combo box.
- The Pump Outflow panel will be displayed, as shown below.
The following sections describe how to interact with the Pump Outflow panel.
Pump Definitions
The Pump Definitions section contains a data grid that lists all the defined pumps along with their flow direction, initial status, and pump mode defined for the selected storage area. Click the [New] button to create a new pump entry in the data grid. Click the [Delete] button to delete the selected pump entry from the data grid. Note that the ID of every newly created pump ID must be unique.
The following column entries are provided in this data grid:
- Defined Pump
This read-only column lists all pumps defined for the selected storage area.
- Flow Direction
This column contains a dropdown combo box that lists the flow direction in which the downstream connection element (i.e., manhole, routing junction, storage area, etc.) receives the pump outflow. The following flow direction options are provided:
- None
- Auxiliary
- Main
- Initial Status
This column contains a dropdown combo box that lists the initial status of the pumps at the start of the analysis. The following initial status options are provided:
- On
- Off
- Pump Mode
This column contains a dropdown combo box that lists the pump modes. The following pump mode options are provided:
- Design Mode
- Pump Curve
Pump Specifications
This section allows the user to define the data for the selected pump listed in the data grid.
The following parameters are provided in this section:
Pump ID
This entry field displays the pump ID corresponding to the selected row in the Pump Definitions data grid. Click on the edit option (i.e., the pencil icon) to edit the pump ID.
Pump mode
This dropdown combo box allows the user to select the pump mode to be used in the analysis for the selected pump.
The following pump modes are provided:
- Design Mode
The pump acts as a transfer pump and does not require a pump curve. This mode is used for preliminary analysis, where the pump’s flow rate equals the inflow rate to the storage area, regardless of the head difference between the storage area and outlet node.
- Pump Curve
The pump operates according to a pump curve specifying the relationship between the pump’s flow rate and conditions at its inlet and outlet nodes. A pump curve is required to be defined by clicking the [Define] button adjacent to the Pump curve dropdown combo box.
Pump curve
This dropdown combo box allows the user to select the pump curve defined in the current scenario.
Note that this dropdown combo box is disabled (i.e., grayed out) when Design Mode is selected as the pump mode.
Clicking the [Define] button displays the Pump Curve Data dialog box, which allows the user to define a new pump curve. Refer to this article in our knowledge base to learn more about the Pump Curve Data dialog box.
Pump initial status
This dropdown combo box allows the user to select the initial pump status at the start of the analysis for the current pump. The following initial status options are provided:
- On – The pump is assumed running at the start of the analysis.
- Off – The pump is assumed not running at the start of the analysis.
Pump start at water depth
This entry field allows the user to define the water depth at which the pump should turn on and start pumping.
Pump stop at water depth
This entry field allows the user to define the water depth at which the pump should turn off and stop pumping.