Good observation about data dams passing data when you first open a GH file (fail!), but you don’t need Python since Stream Gate does the same thing (and more):

data_dam_2019Jul20a.gh (7.4 KB)
Good observation about data dams passing data when you first open a GH file (fail!), but you don’t need Python since Stream Gate does the same thing (and more):

data_dam_2019Jul20a.gh (7.4 KB)