You can cut holes in existing polygon features to create a donut polygon.
- Ensure point snapping is enabled. If it is not, click Point Snapping on the Snapping toolbar.
- Click the Snapping menu on the Snapping toolbar and click Snap To Sketch.
- Click the Cut Polygons tool on the Editor toolbar.
- Sketch the area you want to remove. Make sure the end vertex snaps to the first one, so you end up with a closed polygon.
- To use an existing polygon for the shape of the hole, click Trace on the Editor toolbar palette, click edge of the feature you want to use to cut, and trace around it. As you are tracing, you can change which features are being traced by pointing to them and clicking or dragging.
- Right-click anywhere on the map and click Finish Sketch.
- You now have two polygons. Select only the inner polygon and press the DELETE key.
With edit sketch snapping, you can better construct a closed boundary defining the area you want to remove.
The Clip command is another way of using an existing overlapping polygon to cut the shape of the hole. When using this method, keep in mind that all editable features underneath the feature you are using to clip with will be clipped.
- Select the inner polygon.
- Click the Editor menu and click Clip.
- Set the buffer distance to 0 and choose to discard the area that intersects.
- Click OK.
- Delete the inner polygon.