diff --git a/swmmanywhere/graph_utilities.py b/swmmanywhere/graph_utilities.py
index afbcd0bb..c0d654c9 100644
--- a/swmmanywhere/graph_utilities.py
+++ b/swmmanywhere/graph_utilities.py
@@ -695,7 +695,7 @@ def __call__(self, G: nx.Graph,
             total_weight = 0
             for attr, bds in bounds.items():
                 # Normalise
-                weight = (d[attr] - bds[0]) / (bds[1] - bds[0])
+                weight = (d[attr] - bds[0]) / (bds[1] - bds[0]) + 1e-10
                 # Exponent
                 weight = weight ** getattr(topology_derivation,f'{attr}_exponent')
                 # Scaling