Find sites upstream of a site

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RivEX will generate a dBase file listing all upstream sites in one layer against the input layer.  Sites that have no sites upstream of themselves are coded with a -1.  Therefore all sites are returned in the output as either -1 or a list of upstream IDs.

Sites must be snapped to the network and the ID field must be a numeric value.

Information If you want to find what is upstream of what within a single layer then simply set the Sites to search and Upstream sites to find as the same layer.

If a selection on the input site layer exists RivEX will enable the check box Use only selected sites. If you need to process only a sub set of your sites in the input layer then make sure you check this.  Any selection on the upstream sites layer is ignored.

Find upstream sites dialog

All RivEX generated fields must exist as well as the segment ID tables. Click OK and the tool will execute.

RivEX will first check if the sites intersect the polylines of the network. If any are found not to be intersecting it will drop these from the analysis and the ID's written to an error log file. The error log file is written to ..\RivEX_Workspace\ErrorLogs\FailedSites_SiteLayerName.txt.

Output is written to a dBase file and stored in the networks RivEX_Workspace\Output folder. The name given to this file is the name of the point layer with the suffix of "_UpstreamSites".  The field headings have to be 10 characters or less to be a valid dBase field therefore abbreviations are used and are described below.

Field name



Object ID (ESRI default)


The site ID number from the input layer


The ID of an upstream site


The distance from network mouth for the upstream site

In the screen shot below is a typical table generated by the tool. Site 7426 has four sites upstream of it whilst the other input sites have no sites upstream of them, hence the default -1.

Upstream sites table