Option

Description

Flow Units

Six choices of flow units are available. Selecting a metric flow unit means that all other quantities will be expressed in metric units, while choosing a US flow unit will force all quantities to be expressed in US units.

• CMS - Cubic metre per second.

• LPS - Litre per second.

• MLD - Mega litre per day.

• CFS - Cubic feet per second.

• GPM - Gallon per minute.

• MGD - Mega gallon per day.

The units of previously entered data are not automatically adjusted if the unit system is changed.

Infiltration Model

This option controls how infiltration of rainfall into the upper soil zone of subcatchments is modelled. The choices are:

• Horton

• Green-Ampt

• Curve Number

Changing this option requires re-entering values for the infiltration parameters in each subcatchment.

Routing Method

This option determines which method is used to route flows through the conveyance system. The choices are:

• Steady Flow

• Kinematic Wave

• Dynamic Wave

See the Flow Routing topic for more details.

Allow Ponding

Select this checkbox to allow excess water to collect atop nodes and be re-introduced into the system as conditions permit. In order for ponding to actually occur at a particular node, a non-zero value for its Ponded Area attribute must be used.

Report Control Actions

Select this checkbox if you want the simulation's Status Report to list all control actions taken by the Control Rules associated with a project. This option should only be used for short-term simulation.

Report Input Summary

Select this checkbox if you want the simulation's Status Report to list a summary of the project's input data.

Skip Steady State Periods

Select this checkbox to make the simulation use the most recently computed conveyance system flows during a steady state period instead of computing a new flow routing solution. A time step is considered to be in steady state if there has been no significant change in external inflows, storage volumes, and either node water depths (for dynamic wave routing) or conduit flows (for other forms of routing).

Ignore Rainfall / Runoff

Select this checkbox to ignore all rainfall data and runoff computations. Only user-specified direct inflow time series and dry weather inflows will be considered.