Basinwide Assessment Report New River Basin
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BASINWIDE ASSESSMENT REPORT NEW RIVER BASIN NORTH CAROLINA DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES Division of Water Quality Environmental Sciences Section April 2009 This page was intentionally left blank 2 TABLE OF CONTENTS Section Page LIST OF APPENDICES ................................................................................................................................3 LIST OF TABLES..........................................................................................................................................4 LIST OF FIGURES........................................................................................................................................4 INTRODUCTION TO PROGRAM METHODS..............................................................................................5 BASIN DESCRIPTION..................................................................................................................................6 NEW RIVER HUC 05050001 – UPPER NEW RIVER..................................................................................7 Description .......................................................................................................................................7 Overview of Water Quality .............................................................................................................11 River and Stream Assessment ......................................................................................................15 GLOSSARY ................................................................................................................................................18 LIST OF APPENDICES Appendix Page Appendix B-1. Summary of benthic macroinvertebrate data, sampling methods and criteria. ............20 Appendix F-1. Fish community sampling methods and criteria. ..........................................................27 Appendix F-2. A summary of fish community assessment data for 2008............................................32 Appendix F-3. Fish community data collected from the New River basin, 1998 and 2008. Basinwide sites sampled in 2008 are in bold font..........................................................................36 Appendix F-4. Fish community metric values from 22 wadeable streams in the New River basinwide monitoring program, 2008 ............................................................................................37 Appendix F-5. Fish distributional recods for the New River basin. ......................................................38 Appendix F-6. Habitat evaluations and stream and riparian habitats at 22 fish community monitoring sites in the New River basin, 2008. ..............................................................................40 Appendix F-7. Water quality at 22 fish community sites in the New River basin, 2008.......................46 Appendix F-8. Fish community references...........................................................................................49 Appendix G-1. Flow measurement and flow conditions in the New River basin. .................................50 Appendix S-1. Fish and benthos site summaries for basinwide sites collected in the New River basin for the 2008 cycle. ........................................................................................................54 3 LIST OF TABLES Table Page Table 1. Waterbodies monitored in HUC 05050001 in the New River basin for basinwide assessment, 2003 and 2008. ................................................................................................11 LIST OF FIGURES Figure Page Figure 1. Geographical Relationships of the New River Basin...............................................................6 Figure 2. Level IV Ecoregions of the New River Basin...........................................................................8 Figure 3. Land cover in HUC 05050001 in the New River basin............................................................9 Figure 4. Sampling sites in HUC 05050001 in the New River basin. ...................................................10 4 INTRODUCTION TO PROGRAM METHODS The Division of Water Quality uses a basinwide approach to water quality management. Activities within the Division, including permitting, monitoring, modeling, nonpoint source assessments, and planning are coordinated and integrated for each of the 17 major river basins within the state. All basins are reassessed every five years. The New River basin has been sampled by the Environmental Sciences Section (ESS) four times for basinwide monitoring: 1993, 1998, 2003, and 2008. The ESS collects a variety of biological, chemical, and physical data that can be used in a myriad of ways within the basinwide-planning program. In some program areas there may be adequate data from several program areas to allow a fairly comprehensive analysis of ecological integrity or water quality. In other areas, data may be limited to one program area, such as only benthic macroinvertebrate data or only fisheries data, with no other information available. Such data may or may not be adequate to provide a definitive assessment of water quality, but can provide general indications of water quality. The primary program areas from which data were drawn for this assessment of the New River basin include benthic macroinvertebrates, fish community, ambient monitoring, and aquatic toxicity monitoring for the period 2003-2008. Details of biological sampling methods (including habitat evaluation) and rating criteria can be found in the appendices of this report. Technical terms are defined in the Glossary. This document is structured with physical, geographical, and biological data discussions presented in hydrologic units (HUCs). General water quality conditions are given in an upstream to downstream format. Lakes data, ambient chemistry data and aquatic toxicity data, with summaries, are presented in separate reports. 5 BASIN DESCRIPTION The New River Basin is located within the Blue Ridge Province of the Appalachian Mountains in the northwest corner of the state in Watauga, Ashe and Alleghany counties (Figure 1). It is the state’s 4th smallest river basin, and encompasses a 765 square-mile watershed drained by approximately 825 miles of streams. The New River originates at the confluence of the North Fork New River and South Fork New River in northeastern Ashe County, and then flows northeast into Virginia before eventually flowing into the Kanawha River (Figure 1). The New River meanders across the North Carolina-Virginia state line four times before the confluence of the Little River, the only other major tributary originating in North Carolina, which also flows north into Virginia. The New River is part of the oldest river system in North America. South Fork New River is classified as High Quality Waters (HQW) from Elk Creek near the Watauga-Ashe County line to Dog Creek and is classified as Outstanding Resource Waters (ORW) from Dog Creek to the New River. All North Carolina segments of the New River are classified as ORW. Other HQW waters in the New River basin are: upper segments of Flattop Branch; most of Winkler Creek; Flannery Fork; most of the Howard Creek drainage; a portion of Big Horse Creek and three of its tributaries; and the lowermost segment of Little River. The only other stream segments classified as ORW are Call Creek and the lowermost segment of Old Field Creek. Overall, more than half of the land in the New River basin is forested, with pastureland as the next largest land use. The steep slopes found in the basin limit much of the development and agriculture to the river valleys. Christmas tree farming is a rapidly expanding business in the basin. Figure 1. Geographical Relationships of the New River Basin. 6 NEW RIVER HUC 05050001 – UPPER NEW RIVER Description The North Carolina portion of HUC 05050001 includes the entire New River basin in the state. Most of the counties of Ashe and Alleghany are included, as is a central-to-northeast portion of Watauga. The towns of Sparta (population 1,817; all populations are from year 2000 U.S. Census Bureau data), Jefferson (1,422), West Jefferson (1,081), Boone (13,472), and most of Blowing Rock (1,418) are contained in the HUC. There are two active NPDES dischargers in the HUC with permitted flows of over one million gallons per day (MGD): the Town of Boone’s Jimmy Smith WWTP (permit NC0020621) with permitted flow of 4.82 MGD and discharge to South Fork New River; and United Chemi-Con, Incorporated (permit NC0000019) with permitted flow of 1.018 MGD and discharge to North Fork New River. Four Level IV ecoregions are represented by significant areas within the HUC (Figure 2): New River Plateau, Amphibolite Mountains, Southern Crystalline Ridges and Mountains, and Southern Metasedimentary Mountains.1 • About one-half of the HUC is within the New River Plateau ecoregion, a hilly, high-elevation area used for “pasture, orchards, cropland, livestock and dairy farms, and Christmas tree production.”1 This area has the lowest relief of the four ecoregions in the HUC, with elevations from 2300 feet on the New River floodplain to 4175 feet at Peach Bottom Mountain west-southwest of Sparta. • A western portion of the HUC is within the Amphibolite Mountains. This area is characterized by steep mountains of gneiss and amphibolite (composed mainly of hornblende, a form of amphibole) and by its high plant diversity (driven in part by disjunct populations of more northern species and by the presence