Index: wflow-py/wflow/wflow_delwaq.py
===================================================================
diff -u -re7ac7ba7c964d536375f91ee04354cc9a6c49b89 -rdfb8dcec9c46f4142c469c55c28caaccc0675a0e
--- wflow-py/wflow/wflow_delwaq.py	(.../wflow_delwaq.py)	(revision e7ac7ba7c964d536375f91ee04354cc9a6c49b89)
+++ wflow-py/wflow/wflow_delwaq.py	(.../wflow_delwaq.py)	(revision dfb8dcec9c46f4142c469c55c28caaccc0675a0e)
@@ -687,6 +687,10 @@
                 i_elem_up_left  = -1
                 i_elem_up       = np_ptid[i-1,j  ]
                 i_elem_up_right = np_ptid[i-1,j+1]
+            elif j == n-1:
+                i_elem_up_left  = np_ptid[i-1,j-1]
+                i_elem_up       = np_ptid[i-1,j  ]
+                i_elem_up_right = -1
             else:
                 i_elem_up_left  = np_ptid[i-1,j-1]
                 i_elem_up       = np_ptid[i-1,j  ]