Why are catch basins and inlets represented as points instead of polygons?

[Joshua-Young]

Why are catch basins and inlets represented as points in the stormwater utility network? A more accurate representation of those assets would be polygons just like manholes are represented. In our system the pipes do not go into catch basins or inlets but stop at the walls of those assets.

[DanPatterson]

Are all catch basins and inlets of a fixed size?  If not, perhaps their indeterminate geometry makes a location a safer option.

[RobertKrisher]

The boundary of a basin should also be modeled using the BMP Boundary asset group in the Structure Boundary layer. Each Basin will then contain all the BMP Inlets, BMP Points, and outlets associated with the basin. The various device features contained within the basin allow you to model the connectivity/flow for how water can enter/exit the basin.

See screenshot from sample data below:

[JonahW]

I've only seen stormwater detention ponds represented as polygons. Catch Basins, Manholes, Inlets, and Outlets are usually represented as points. Those locations are usually GPS'ed as points. We also have thousands of those assets and seems like a waste of time to digitize as polygons. It simplifies the data structure and no need to record every single vertex of a polygon which can have a bigger impact on querying data in a GIS. My recommendation is to keep it simple stick with points to manage those assets. 

[Nick_Creedon]

I suppose each scenario/workflow is different. We would never consider makings Inlets, Manholes or catch basins polygons. We have thousands represented in our maps. For really large underground structures, we use polygons, to give us a better idea of the structure when locating it for OUPS. All of our storm structures are for the most part uniform, we know what to expect when we are working with a storm structure. If there are any anomalies, we track that in the attribution. Since there are thousands of each type of structure, using points with symbology is the most efficient for us and it has proven to work well for our organization.

Boils down to how precise you are wanting to visualize your underground utilities. We take a large-scale approach for symbolizing our utilities because we have so much to display. Turning each point into a polygon would get messy for us.

[RobertKrisher · Accepted solution]

If you want to capture your basins you can choose to them as a point (BMP Point), polygon (BMP Boundary) or both, depending on your preferences.

[Joshua-Young]

Our catch basins and inlets are currently points and that is how we would like to keep them. I thought at one-point things like manholes were being captured in the utility network as polygons and we wanted to be consistent in how things are represented. However, I am not finding that in the latest version of the models. I guess I am misremembering things (not the first time that's happened) or manholes were changed back to points.

Thank you for the feedback. We are going to stick with using points and use associations to stop the pipes at the walls of the features. I am moving us from our geometric networks to utility networks and still figuring out how everything is intended to work.