Hydraulic breaches occur in certain circumstances when flow paths intersect Gutter type Hydraulic Controls. Basically, a hydraulic breach occurs when a flow path can not find a pixel of lower elevation in which to flow to within a set elevation or 'number of pixels traversed' threshold. This is designed to simulate ponding behind the gutter and eventual breach due to overtopping. Hydraulic breaches are further explained in the algorithm section and the key challenges section and are highly dependent on the parameters set in the Project Options | Hydraulic Structures form.
As shown above, by selecting the rows in the Hydraulic Breach form the location of the hydraulic breaches is shown as a hatched yellow circle in the background. It can be seen that these hydraulic breaches occur in areas where flow would pond behind the gutter.
