Putting a sink in a stream network?

04-22-2012 01:55 AM
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New Contributor
Lets see if this makes sense...
I'm fairly new to this program, but have been trying to show where a flow will go if I interrupt it.  I've created a stream network based on a real watershed, but I want to block the flow in one of the tributaries to see (well, prove a theory)  where it will form a new path. 
How can I go about this?
The stream network I made did not have a pour point, I was able to use to fill-flow direction-flow accumulation- [condition to form a stream network] - stream link.  This formed a perfect match to the known stream network

I've discovered how to create a sink, but cannot incorporate it into the model to divert the flow (I guess I am not putting it in right)
I thought I created a pour point, but no image resulted when I tried to run it in the model.

Should I use a different methodology to model the network?
Is there a way I can place the sink stipulation into the DEM before beginning the process to get a stream network without it being filled?
or am I going about this all wrong???
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Regular Contributor II
What I would do is use ArcHydro.

  1. Run the DEM reconditioning to "burn in" the streams. Result > agreedem

  2. Run the fill sinks function. Result > fil

  3. Run the flow direction function. Result > fdr

Now you can use the flow path tracing tool with the fdr to see where the flow goes. If it gives you results you expect, then move to the next step. If not, you may you may need to check your agreestream polyline layer.

Then do it again. This time create an "innerwalls" polyline layer and "block" the creek by putting an innerwalls line accross the agreestream polyline where you want to block flow. Then follow these steps:

  1. Run the DEM reconditioning to "burn in" the streams. Result > agreedemblk

  2. Run the Build Walls tool using the agreedem and the innerwalls layer. DONOT use a breech line (this would typically be the agreestreams layer). Results > walleddem

  3. Run the fill sinks function. Result > filblk

  4. Run the flow direction function. Result > fdrblk

Now you will have a new fdrblk dem the will be filled in behind the "blockage" and you can see the flow direction your DEM gives you by using the flow path tracing tool
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