If I know that 10,000+ gallons of water were going to be dropped at a single point how could I model where it would flow.

I would prefer something that worked in ArcGIS and could create a layer.

  • the single point release is on land
    – jrhicks
    Sep 21, 2012 at 18:43
  • 5
    How realistic does the model need to be? (Most GIS calculations are not aimed at reproducing actual flows and are good only for rough estimation of cumulative flow or delineation of flow basins.) A truly realistic model would account for surface cover and roughness, soil permeability, soil moisture, viscosity of the liquid, rate of flow onto the point, and more, as well as the surface elevation. For an amusing account of one extreme example, visit what-if.xkcd.com/12.
    – whuber
    Sep 21, 2012 at 19:30

1 Answer 1


ESRI has a good support section on hydrologic analysis. Also, there is a pretty good video tutorial here on how to create drainage networks in ArcMap. The attached image from ESRI shows a stream network created using ArcMap's hydrologic tools and a digital elevation model (DEM) available from USGS Earth Explorer.

enter image description here

  • Could you provide any further information on hydrologic modeling, (such as books)? I am working on NED data at the continental scale.
    – derelict
    Aug 13, 2013 at 14:21

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