Using a Design Subzone for Taildrain Design

There is often a need to take surface runoff away from a optisurfaced field in a controlled manner. An example is a taildrain at the lower end of the field. The taildrain maybe required to flow in one direction where as the basic OptiSurface design at the lower end of the field could run in two directions or be undulating.

This design requirement is easily solved with a design subzone. A design subzone allows the designer to over ride the global design settings defined for the boundary zone (ie whole field). In this example below the design subzone is forcing the cross slope to run in one direction, with negative slope meaning it will run from right to left when looking up the field. This is a 90ha field that was landformed for sugar cane which will be irrigated with trickle tape.

The subzone can be seen here as a red rectangular polygon and the cut fill map gives an indication of the extra earthworks required to force the water to drain one way.

Note: In OptiSurface Designer (V1.0) the 4th level of the project explorer tree (left side of image) has be removed. To access the subzones now, you need to double click on the ‘Design Zones’ item in the tree or use the Menu: Edit>>Design Zones…