I am using the HEM Add-On tool which converts points into flags in ArcGIS 10, and it works great. Here is some online documentation: http://proceedings.esri.com/library/userconf/proc11/uc/papers/3110_87.pdf-- Hydrography Event Management (HEM) Tools New Features as of FY2011 - Additional new functionality includes a stand-alone tool to convert any point feature into network flags in order to do network analysis... http://www.epa.gov/waters/tools/hem/index.html-- It was developed by the Bureau of Land Management (BLM) with input from EPA and USGS. The HEM tool and associated documentation are available for download from: http://nhd.usgs.gov/tools.html
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