I3: Oral Presentation C Thursday, 2:30 � 3:00 pm C Lake Superior Ballroom MN

Georeferencing Water Quality Information to the National Hydrography Dataset

Mark Olsen, Carrie Bartz
Minnesota Pollution Control Agency
520 Lafayette Rd
St. Paul, MN  55155
mark.olsen@pca.state.mn.us

This paper describes the work being done by the Minnesota Pollution Control Agency to georeference or link water quality information to surface water features in the National Hydrography Dataset (NHD). This effort is being accomplished through the use of the Reach Indexing Tool, developed by the U.S. Environmental Protection Agency. 

The Reach Indexing Tool for NHD (NHD-RIT) is an ArcView extension that allows users to georeference surface water data (such as, 305(b) use support assessments for aquatic life and swimming, Total Maximum Daily Loads, water quality standards, surface water monitoring stations and NPDES discharge locations) to the NHD. The process of identifying and assigning surface water ID's or attributes to portions of the NHD is referred to as Reach Indexing.