Creating hole in polygon while using ‘auto complete polygon’ in ArcMap?

Creating Holes in Polygons While Using ‘Auto Complete Polygon’ in ArcMap: A Human’s Guide

ArcMap. It’s a classic, right? Even with Esri nudging everyone towards ArcGIS Pro, plenty of us still rely on it. And let’s face it, sometimes you just need to draw a polygon right next to another one. That’s where the ‘Auto Complete Polygon’ tool comes in clutch, making sure those shared borders line up perfectly. But what happens when you need a hole in that polygon? Like a lake with an island, or maybe a building with a courtyard in the middle? That’s where things get a little trickier with the ‘Auto Complete Polygon’ tool. So, let’s dive into how to make those “donut polygons” happen.

The Challenge: Donut Polygons Aren’t Always Easy

The ‘Auto Complete Polygon’ tool is a champ at creating those perfectly aligned, side-by-side polygons. Think land parcels neatly snuggled together, or different soil types butted up against each other. It’s all about that shared boundary. But throw a hole into the mix, and suddenly, things aren’t so straightforward. How do you tell ArcMap you want a void inside your new polygon?

The Solution: A Step-by-Step Walkthrough

Alright, here’s the secret sauce. Follow these steps, and you’ll be creating donut polygons like a pro:

Other Ways to Skin a Cat (Alternative Methods)

Okay, so that’s one way to do it. But GIS is all about options, right? Here are a couple of other tricks for creating holes in polygons:

• The Clip Tool: Think of this as cookie-cutting. Draw your outer polygon and your hole as separate shapes. Then, use the Clip tool to “cut” the hole out of the outer shape. It’s like using a donut cutter on a sheet of dough.
• The Cut Polygon Tool: This one’s more hands-on. It lets you manually trace the exact shape of the hole you want inside an existing polygon.

A Few Things to Keep in Mind

• Snapping is Your Friend: Seriously, turn on snapping. It makes sure all your lines connect perfectly, which is super important for clean data.
• Geodatabases are Key: If you want to be really sure everything lines up, use a geodatabase feature class. Trust me, it’s worth it.
• ArcGIS Pro is Out There: Remember, ArcMap’s not getting any younger. ArcGIS Pro is the future, so start thinking about making the switch. The workflows might be a little different, but the basic ideas are the same.

Final Thoughts

Creating holes in polygons with the ‘Auto Complete Polygon’ tool in ArcMap might seem a little weird at first, but once you get the hang of the “Finish Part” trick, you’ll be whipping out donut polygons like it’s nobody’s business. So go forth, create those lakes with islands, and remember to have fun with it! After all, GIS is all about solving problems and making maps that tell a story.