Flow Dividers are drainage system nodes that divert inflows to a specific conduit in a prescribed manner. A flow divider can have no more than two conduit links on its discharge side. Flow dividers are only active under Steady Flow and Kinematic Wave routing and are treated as simple junctions under Dynamic Wave routing.
There are four types of flow dividers, defined by the manner in which inflows are diverted:
- Cutoff (diverts all inflow above a defined cutoff value)
- Overflow (diverts all inflow above the flow capacity of the non-diverted conduit)
- Tabular (uses a table that expresses diverted flow as a function of total inflow)
- Weir (treats diverted flow as linearly proportional to the inflow above a defined cutoff value).
| Field | Description | ||||||||
| Name | User-assigned divider name. | ||||||||
| X-Coordinate | Horizontal location of the divider on the Study Area Map. If left blank then the divider will not appear on the map. | ||||||||
| Y-Coordinate | Vertical location of the divider on the Study Area Map. If left blank then the divider will not appear on the map. | ||||||||
| Inflows | Click the ellipsis button (or press Enter) to assign external direct, dry weather or RDII inflows to the divider. | ||||||||
| Treatment | Click the ellipsis button (or press Enter) to edit a set of treatment functions for pollutants entering the node. | ||||||||
| Invert El. | Invert elevation of the divider (feet or meters). | ||||||||
| Max. Depth | Maximum depth at the divider (i.e., distance from the invert to the ground surface) (feet or meters). If "auto" or zero then the distance from the invert to the top of the highest connecting link will be used. | ||||||||
| Initial Depth | Depth of water at the divider at the start of the simulation (feet or meters) | ||||||||
| Surcharge Depth | Additional depth of water beyond the maximum depth that is allowed before the divider floods (feet or meters). This parameter can be used to simulate bolted manhole covers or force main connections. | ||||||||
| Ponded Area | Area occupied by ponded water atop the divider after flooding occurs (sq. feet or sq. meters). If the Allow Ponding simulation option is turned on, a non-zero value of this parameter will allow ponded water to be stored and subsequently returned to the drainage system when capacity exists. | ||||||||
| Diverted Link | Name of link which receives the diverted flow. | ||||||||
| Type |
Type of flow divider. Choices are:
|
||||||||
| CUTOFF DIVIDER | |||||||||
| - Cutoff Flow : | Cutoff flow value used for a CUTOFF divider (flow units). | ||||||||
| TABULAR DIVIDER | |||||||||
| - Curve Name : | Name of Diversion Curve used with a TABULAR divider (double-click to edit the curve). | ||||||||
| WEIR DIVIDER | |||||||||
| - Min. Flow : | Minimum flow at which diversion begins for a WEIR divider (flow units). | ||||||||
| - Max. Depth : | Vertical height of WEIR opening (feet or meters). | ||||||||
| - Coefficient : | Product of WEIR's discharge coefficient and its length. Weir coefficients are typically in the range of 2.65 to 3.10 per foot, for flows in CFS. | ||||||||
Note: Flow dividers are operational only for Steady Flow and Kinematic Wave flow routing. For Dynamic Wave flow routing they behave as Junction nodes.