I see that Visual Soakaway Design 4 designs filter trenches. How does it do that?
Visual Soakaway Design 4 designs filter trenches in the same way that it designs soakaways, however, when the designer chooses the filter trench option he/she must select a percentage of the impermeable area which will overflow out of the soakaway. In doing this, the majority of the volume is still infiltrating into the ground with only a predefined amount being released into the watercourse. This attenuation protects the integrity of the watercourse from excessive erosion.
