Sum field and use that sum to populate existing field in same table using ArcGIS ModelBuilder?

Question

I am trying to break down land uses in a watershed by making a tool in ModelBuilder. Right now I am clipping a land use layer by a watershed polygon, dissolving land use layer by land use code, converting the area of each dissolved land use to acreage, then adding a new field field for total watershed acreage, which i will then create a new field to divide the two together to get a percentage.

Where I am hung up on now is populating the total watershed acreage field. Is there a way in ModelBuilder where I can sum all of the areas of the dissolved land use acreages and populate that sum into each cell of the total watershed acreage field? I imagine it is possible through the calculate field tool. I am not all that familiar with python, but i think that might be the way to go.

Answer 1

With model builder, the best solution is to use "summary statistics" then join the resulting table with your dissolved feature class. You'll need to add a new field with a single value, so that the "summary statistics" works on the full table.