diff --git a/swmmanywhere/geospatial_utilities.py b/swmmanywhere/geospatial_utilities.py
index 8d7f08a8..47af36d1 100644
--- a/swmmanywhere/geospatial_utilities.py
+++ b/swmmanywhere/geospatial_utilities.py
@@ -417,7 +417,7 @@ def delineate_catchment(grid: pysheds.sgrid.sGrid,
         # Snap the node to the nearest grid cell
         x, y = data['x'], data['y']
         grid_ = deepcopy(grid)
-        x_snap, y_snap = grid_.snap_to_mask(flow_acc > 5, (x, y))
+        x_snap, y_snap = grid_.snap_to_mask(flow_acc >= 0, (x, y))
         
         # Delineate the catchment
         catch = grid_.catchment(x=x_snap, 
diff --git a/swmmanywhere/graph_utilities.py b/swmmanywhere/graph_utilities.py
index f069100f..a2262d71 100644
--- a/swmmanywhere/graph_utilities.py
+++ b/swmmanywhere/graph_utilities.py
@@ -208,11 +208,15 @@ def __call__(self,
             G (nx.Graph): The same graph with an ID assigned to each edge
         """
         edge_ids: set[str] = set()
-        for u, v, data in G.edges(data=True):
+        edges_to_remove = []
+        for u, v, key, data in G.edges(data=True, keys = True):
             data['id'] = f'{u}-{v}'
             if data['id'] in edge_ids:
                 logger.warning(f"Duplicate edge ID: {data['id']}")
+                edges_to_remove.append((u, v, key))
             edge_ids.add(data['id'])
+        for u, v, key in edges_to_remove:
+            G.remove_edge(u, v, key)
         return G
 
 @register_graphfcn
@@ -409,6 +413,39 @@ def create_new_edge_data(line, data, id_):
 
         return graph
 
+@register_graphfcn
+class fix_geometries(BaseGraphFunction,
+                     required_edge_attributes = ['geometry'],
+                     required_node_attributes = ['x', 'y']):
+    """fix_geometries class."""
+    def __call__(self, G: nx.Graph, **kwargs) -> nx.Graph:
+        """Fix the geometries of the edges.
+
+        This function fixes the geometries of the edges. The geometries are
+        recalculated from the node coordinates.
+
+        Args:
+            G (nx.Graph): A graph
+            **kwargs: Additional keyword arguments are ignored.
+
+        Returns:
+            G (nx.Graph): A graph
+        """
+        G = G.copy()
+        for u, v, data in G.edges(data=True):
+            start_point_node = (G.nodes[u]['x'], G.nodes[u]['y'])
+            start_point_edge = data['geometry'].coords[0]
+            end_point_node = (G.nodes[v]['x'], G.nodes[v]['y'])
+            end_point_edge = data['geometry'].coords[-1]
+            if (start_point_edge == end_point_node) & \
+                    (end_point_edge == start_point_node):
+                data['geometry'] = data['geometry'].reverse()
+            elif (start_point_edge != start_point_node) | \
+                    (end_point_edge != end_point_node):
+                data['geometry'] = shapely.LineString([start_point_node,
+                                                       end_point_node])
+        return G
+
 @register_graphfcn
 class calculate_contributing_area(BaseGraphFunction,
                                 required_edge_attributes = ['id', 'geometry', 'width'],
diff --git a/tests/test_data/demo_config.yml b/tests/test_data/demo_config.yml
index 16b7e5f4..10a5b698 100644
--- a/tests/test_data/demo_config.yml
+++ b/tests/test_data/demo_config.yml
@@ -16,6 +16,7 @@ graphfcn_list:
   - assign_id
   - format_osmnx_lanes
   - double_directed
+  - fix_geometries
   - split_long_edges
   - calculate_contributing_area
   - set_elevation
diff --git a/tests/test_graph_utilities.py b/tests/test_graph_utilities.py
index 45251599..ccaa3a72 100644
--- a/tests/test_graph_utilities.py
+++ b/tests/test_graph_utilities.py
@@ -260,3 +260,19 @@ def test_iterate_graphfcns():
     for u, v, d in G.edges(data=True):
         assert 'id' in d.keys()
         assert 'width' in d.keys()
+
+def test_fix_geometries():
+    """Test the fix_geometries function."""
+    # Create a graph with edge geometry not matching node coordinates
+    G = load_graph(Path(__file__).parent / 'test_data' / 'graph_topo_derived.json')
+    
+    # Test doesn't work if this isn't true
+    assert G.get_edge_data(107733, 25472373,0)['geometry'].coords[0] != \
+        (G.nodes[107733]['x'], G.nodes[107733]['y'])
+
+    # Run the function
+    G_fixed = gu.fix_geometries(G)
+
+    # Check that the edge geometry now matches the node coordinates
+    assert G_fixed.get_edge_data(107733, 25472373,0)['geometry'].coords[0] == \
+        (G_fixed.nodes[107733]['x'], G_fixed.nodes[107733]['y'])
\ No newline at end of file