Tuflow and estry manual Version 3

Node or Pit: Not used. Channel: If set to true (ie. “T”), the storage based on the width of the channel over half the channel length is assigned to both of the two nodes connected to the channel. See Section 3.13.2.2 for further discussion.
Logical
5	Length_or_ANA	Node or Pit: Since Build 2005-05-AN, adds the value specified as additional nodal area (surface area in m^2). If no nodal area data exists for the node, either by specifying Use_Chan_Storage_at_Node above or using a NA table, TUFLOW automatically creates an NA table of constant surface area. Prior to Build 2005-05-AN, not used.