I want to find the storage in dams snapped to a set of polylines defining rivers above specific points on each river.

Using ArcMap 10.3 I have the polylines representing rivers, the points denoting dams, snapped to the river polylines, with a storage variable, and the points on the rivers where I want to calculate the cumulative upstream dam storage.

How to proceed?

  • 1
    Do you have spatial analyst license?
    – FelixIP
    Jun 13, 2018 at 18:52
  • If you have a DEM, WhiteboxTool's impoundment index may be useful for this application. Jun 13, 2018 at 20:45
  • I have Spatial Analyst and 3D Analyst licenses. My problem now is to create a geometric network from river polylines (2d) and a DEM to create the river network with the correct from- to- flow direction and connectivity. Jun 14, 2018 at 14:07

1 Answer 1


If your river network is a geometric network you could automate with ModelBuilder some sort of find upstream, select and summarise. Alternatively you could explore RivEX and use the find all upstream sites tool then do a simple summation of values.

  • Thanks for advice - I have RivWEx and will explore its solution Jun 14, 2018 at 12:00
  • My problem now is to create a geometric network from polylines. I have converted teh 2d opolyliines to 3D and added z-values from a DEM. However this only gives values for each segment. a 3D Jun 14, 2018 at 13:52
  • Are you trying to set flow direction? Suggest you read the help file page (Set Flow Direction (Data Management)). This will set the flow direction so the searching tools will work. This does assume the person who created the network knows that water flows down hill... ;)
    – Hornbydd
    Jun 14, 2018 at 16:22
  • Thanks, I see. But I'm stuck on how to produce a "geometric network" (which will hopelfully have z values at verticies, or at least at beginning and end of segments which are joined). Jun 14, 2018 at 17:15

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