diff --git a/mosartwmpy/_version.py b/mosartwmpy/_version.py
index 906d362..43c4ab0 100644
--- a/mosartwmpy/_version.py
+++ b/mosartwmpy/_version.py
@@ -1 +1 @@
-__version__ = "0.6.0"
+__version__ = "0.6.1"
diff --git a/mosartwmpy/grid/grid.py b/mosartwmpy/grid/grid.py
index bf61515..a31261c 100644
--- a/mosartwmpy/grid/grid.py
+++ b/mosartwmpy/grid/grid.py
@@ -273,7 +273,7 @@ def __init__(self, config: Benedict = None, parameters: Parameters = None, empty
         # parameter for calculating number of main channel iterations needed
         # phi_r
         phi_main = np.where(
-            (self.mosart_mask > 0) & (self.channel_length > 0),
+            (self.mosart_mask > 0) & (self.channel_length > 0) & (self.channel_width > 0),
             self.total_drainage_area_single * np.sqrt(self.channel_slope) / (self.channel_length * self.channel_width),
             0
         )
@@ -352,7 +352,7 @@ def __init__(self, config: Benedict = None, parameters: Parameters = None, empty
         # parameter for calculating number of subnetwork iterations needed
         # phi_t
         phi_sub = np.where(
-            self.subnetwork_length > 0,
+            (self.mosart_mask > 0) & (self.subnetwork_length > 0) & (self.subnetwork_width > 0),
             (self.area * np.sqrt(self.subnetwork_slope)) / (self.subnetwork_length * self.subnetwork_width),
             0,
         )