inconsistent treatment of sinks in river network setup
If L11 != L0, then fdir < 0 marks sinks, but that does not work if L11 = L0. In the latter case fdir has to be 0. This was reported by @extostem.
If L11 != L0, then fdir < 0 marks sinks, but that does not work if L11 = L0. In the latter case fdir has to be 0. This was reported by @extostem.