Boundary problem

[Niza]

Hello everyone :)

I just started working with HEC-RAS and i have millions of questions :)
I found one similar exercise to my problem and according to that exercise i worked through my problem..

I have to model water level in one river..and data i have is Q(1/100), cross sections (17 of them), mannings n and distance between cross sections.

I entered all data's but stopped when i was entering data about flow (steady flow)

I chose WS boundary...and it opened new window...in example i have they wrote number 1 under Known WS El...
so my question is..what is this number...what should i write there...?
One more question is about Number of profiles (also in window about steady flow)
what exactly this is..?

Thank you so much for any of your help in advance

Niza :)

edit:

I made same project through one program in FORTRAN and i have some differences in final result of WS...could it be that my boundary is mistaken?

The difference is up to 0,5m in WS and it is not that insignificant...
How to tell my calculation in hec ras is correct?

Pardon my doubt...i am new at this program as i said..and am still learning to trust its results