Headwater Streams - Information, Delineation and Spatial Representation
The North Carolina Department of Environmental Quality (DEQ) has multiple divisions where maps depicting streams are used daily to complete program business and environmental goals. The Division of Water Resources (DWR) is a DEQ division where staff are dependent on United States Geological Survey (USGS) and Natural Resource Conservation Service (NRCS) soil maps to facilitate water quality monitoring and modeling programs, 401 certification, compliance and enforcement, water supply watershed protection, buffer and NPDES permitting. However, these maps and their depiction of streams were not originally intended for many of the technical and regulatory applications used today and consequently do not always accurately represent streams on the landscape. This fact is particularly true of 1st and 2nd order streams commonly referred to as headwater streams. Many states, including North Carolina, regulate activity in and near headwater streams for protection of water quality and aquatic resources as defined by the state administrative code. Accurate representation of streams, or at least, “known accuracy” of streams on presently used maps, is a basic requirement for use in research and regulatory programs across North Carolina. Improved stream maps benefit other state, federal and local government programs as well. The Ecosystem Enhancement Program and the North Carolina Department of Transportation need accurate stream maps in
- planning for mitigation needs,
- evaluating impact alternatives,
- identifying potential mitigation sites,
- and, facilitating hydraulic issues encountered in road construction and maintenance.
Additionally, timesavings will be realized by these agencies and the consultants that contract for them since more accurate maps will result in fewer stream delineations.
In response to the need for accurate headwater stream maps, the North Carolina Division of Water Resources, The North Carolina Department of Transportation, and North Carolina State University partnered in early 2004 to initiate a pilot project to develop a stream map for the state that more accurately depicts 1st and 2nd order streams. Additionally, DENR Center of Geographic Information and Analysis (CGIA) was tasked to produce a more accurate state-wide stream map in response to the Hurricane Recovery Act (Senate Bill 1152) passed in late 2004. Due to monetary, time and program constraints, neither program mapping effort alone will produce the multiple-use stream map needed by the state. For this reason, an agreement between DWR and CGIA was made to integrate the headwater stream mapping products with CGIA to produce one North Carolina stream map that meets multiple use requirements.