Sewer Inlet Catchment Delineatoin

Question

Hello, I am trying to use arcmap and the hydrology or hydro tools to delineate the catchment for a single sewer inlet location. I have 3 ft by 3 ft DEM data and a single vector point dataset. I'm currently using the Fill and Flor Direction Tools and then the Watershed tool to get the catchment area. However, I am not getting good results and I am not sure these tools were designed to be used on such a small scale.

I have attached a picture of one of my test runs. I'm not sure why the delineated watershed stops where it does instead of continuing to go up, since the flow direction value of 4 should be flowing down. (relative to the picture.)

If anyone has done something similar to this or has any suggestions It would be greatly appreciated. Thanks.

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example_delineation.png

GBacon_2-1661954027708.png

BrianJeffries · Answer

To get appropriate results, you probably need to specify the raster environment -- especially if you are providing vector data (points) that are going to be rasterized on the fly when you run the Watershed tool.

The relevant environments include:

Extent  (must include the area you want to delineate)
Snap Raster
Cell Size

Hope this helps.

Thanks for the quick reply. This did the trick. Thanks for the help!

curtvprice · Answer

To get appropriate results, you probably need to specify the raster environment -- especially if you are providing vector data (points) that are going to be rasterized on the fly when you run the Watershed tool.

The relevant environments include:

Extent  (must include the area you want to delineate)
Snap Raster
Cell Size

Hope this helps.