Thanks for trying to help. Perhaps an example would help clarify things?
I have a basin called 14B and the program gives an area, a channel slope, and a main channel length of 27.01 miles (verified as correct). Nearby is basin 16B, which shows a main channel length of 13.1 miles.
They both flow into a junction called 27C, which shows appropriately the combined area of the two basins. However, the main channel length is given as 25.1 miles?? It should be the cumulative longest flow path, but I am having a hard time figuring out where 25.1 miles even comes from. It seems