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My sanitary sewer data (shapefiles) is being merged with data from another GIS firm for a large project and they are asking me to flip all my line segments because they believe they are backwards but I believe they are backwards. Shouldn't the upstream point be the start point and the downstream point be the end point?

How do you create pipes, upstream to downstream or downstream to upstream?

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Indeterminate flow direction (see node, sink & source diagrams)… – Mapperz May 24 '13 at 15:54

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