Index: wflow-py/wflow/wflow_lib.py
===================================================================
diff -u -rd6ff5f0cdbb84e579b51b352ba41ed7097c0f2f4 -r1e97f1b2e3a9575c7e7342f52af55db068e6ec62
--- wflow-py/wflow/wflow_lib.py	(.../wflow_lib.py)	(revision d6ff5f0cdbb84e579b51b352ba41ed7097c0f2f4)
+++ wflow-py/wflow/wflow_lib.py	(.../wflow_lib.py)	(revision 1e97f1b2e3a9575c7e7342f52af55db068e6ec62)
@@ -283,13 +283,14 @@
         ] = np_outflow[np_outflow < 0]
         outflow_linked = numpy2pcr(Scalar, np_outflow_linked, 0.0)
 
+        fl_nr_loop = float(nr_loop)
         storage = (
             storage_start
-            + (inflow * timestepsecs / nr_loop)
-            + (prec_av / nr_loop / 1000.0) * ResArea
-            - (pet_av / nr_loop / 1000.0) * ResArea
-            - (cover(outflow, 0.0) * timestepsecs / nr_loop)
-            + (cover(outflow_linked, 0.0) * timestepsecs / nr_loop)
+            + (inflow * timestepsecs / fl_nr_loop)
+            + (prec_av / fl_nr_loop / 1000.0) * ResArea
+            - (pet_av / fl_nr_loop / 1000.0) * ResArea
+            - (cover(outflow, 0.0) * timestepsecs / fl_nr_loop)
+            + (cover(outflow_linked, 0.0) * timestepsecs / fl_nr_loop)
         )
 
         waterlevel = ifthenelse(