location == Estry Control File (.ecf)

command == Read GIS Network

description == Used to define channel and node locations and attributes. Common channel types include, open channels, culverts, bridges, weirs. The difference between the 1d_nwkb and standard 1d_nwk is that the pblockage attribute field accepts characters allowing the user to input matrix blockage.

manual link == https://www.tuflow.com/Download/TUFLOW/Releases/2017-09/TUFLOW%20Manual.2017-09-AC.pdf
manual page == 96