The Reach Indexing Tool for the National Hydrography Dataset: Functionality and Impacts on State Water Programs

Author: Christoph Spoerri
Organization: Research Triangle Institute

3040 Cornwallis Road
PO Box 12194
Research Triangle Park, NC 27709-2194
USA

Phone: 919-485-7771
Fax: 919-485-7777
spoerri@rti.org

Research Triangle Institute (RTI), under contract with the U.S. EPA, is developing a reach indexing tool (RIT) for the National Hydrography Dataset (NHD). NHD is a spatial database containing national surface water features. The NHD-RIT is an ArcView GIS-based tool to help states georeference surface water entities to NHD using the dynamic segmentation data model. The tool is primarily used to index Clean Water Act Section 303(d) and 305(b) water bodies and state water quality standards. This paper discusses the evolution, purpose, and functionality of the NHD-RIT and its impacts on states' Clean Water Act programs.