Channel and node topography are defined using tables. Channels require a table describing its hydraulic properties with height, and nodes require a table describing its storage volume (table of surface area versus height).
Channel and nodal property tables are assumed to be undefined above the highest point in the tables. If a computed water level exceeds the top of a table an ERROR occurs. If this occurs ten times for any one channel or node the run stops. Depth Limit Factor can be used to allow water levels to exceed the top of hydraulic properties and nodal area tables. Head limit checks are not applied to bridges or culverts.