Biological assessment

1.0INTRODUCTION 6

2.0DESCRIPTION OF ACTION AREA 6

2.1R-2518 and R-2519 Project Description 6

2.2Construction areas 8

2.3Areas of Indirect Impacts 9

2.4Areas of Conservation Measures 9

3.0ENVIRONMENTAL BASELINE 9

3.1FRENCH BROAD RIVER SUBBASINS Affected BY PROPOSED ACTION 9

3.1.1Subbasin 04-03-04 10

3.1.2Subbasin 04-03-06 10

3.1.3Subbasin 04-03-07 10

3.1.4Water Quality of the Nolichucky River Basin 10

3.2SPECIES DESCRIPTION 17

3.2.1Characteristics 17

3.2.2Distribution and Habitat Requirements 19

3.2.3Threats to Species (Particularly the Nolichucky River Population) 20

3.3DESIGNATED CRITICAL HABITAT 23

3.4PAST and FUTURE FEDERAL ACTIONS IN Nolichucky basin 26

3.4.1NCDOT/FHWA 26

3.4.2National Resources Conservation Service 28

4.0potential EFFECTS OF PROPOSED ACTION 28

4.1DIRECT IMPACTS 29

5.0PROPOSED AVOIDANCE AND MINIMIZATION MEASURES 38

5.1STANDARD MEASURES 38

5.1.1Erosion Control Measures 38

5.1.2Bridge Deck Drainage 39

5.1.3Preconstruction Survey 39

5.1.4Agency Coordination 39

5.2PROJECT SPECIFIC MEASURES 40

6.0determination of effects 42

6.1DIRECT IMPACTS-APPALACHIAN ELKTOE 42

6.1.1Stream Fill (Substrate (Habitat) Disturbance/Loss) 42

6.1.3Alteration of Flows/Channel Stability 51

6.1.4Roadway Runoff 52

6.2INDIRECT IMPACTS-APPALACHIAN ELKTOE 53

6.2.1Disruption of Fish Host Migration 53

6.2.2Potential for Toxic Spills 54

6.2.3Indirect Effects on Land Use 54

6.3CUMULATIVE IMPACTS-APPALACHIAN ELKTOE 58

6.4DIRECT IMPACTS-CRITICAL HABITAT 59

6.5INDIRECT IMPACTS-CRITICAL HABITAT 60

6.6CUMULATIVE IMPACTS-CRITICAL HABITAT 60

7.0CONSERVATION MEASURES AND PROPOSED MEASURES TO OFFSET IMPACTS 61

7.1Mussel Relocation 61

7.1.1Relocation Methods 62

7.1.2Selection of Relocation Sites 63

7.1.3Collection of Mussels at Impact Site 63

7.1.4Data Processing 63

7.1.5Transportation to Relocation Site 64

7.1.6Preparation of Relocation Site 64

7.1.7Monitoring 64

7.2.1Fish Sampling Survey Methods: 65

7.2.2Macroinvertebrate Sampling Methods 65

7.3Riparian Habitat Protection 67

7.4On-Site Stream Mitigation 68

7.5River Geomorphology Monitoring 71

7.5.1Existing Condition Surveys 71

7.5.2Data Reporting 72

7.6Erosion Control Practices/Habitat Monitoring 72

7.7Japanese Knotweed Control Research 72

8.0OTHER FEDERALLY PROTECTED SPECIES 73

9.0Literature Cited 86

Table 1. Best Usage Classifications in the Nolichucky River Basin. 10

Table 2. EPT Scores for Water Bodies Monitored in Nolichucky River Basin for Basinwide Assessment. 12

Table 3. Fish Community Assessments Conducted by TVA in Nolichucky River Basin. 13

Table 4. NPDES Permitted Dischargers in Nolichucky River Basin. 14

Table 5. Rare Aquatic Species in the Nolichucky River Basin in North Carolina. 16

Table 6. Fish species collected from the Little Tennessee River (NC) that contained encysted Alasmidonta raveneliana glochidia. 17

Table 7. Fish species collected from the Tuckasegee River (NC) on April 21, 2004, and used for laboratory induced infestations. 17

Table 8. Threats to Appalachian elktoe in Nolichucky River. 22

Table 9. Distances from permitted sites to Cane River. 28

Table 10. Distances from permitted sites to South Toe River. 29

Table 11. Distances from permitted sites to North Toe River (R-2519B) 31

Table 12. Retaining walls designed to reduce stream impacts. 39

Table 13. Impacts to Cane River (CR) Tributaries from west to east. 43

Table 14. Impacts to South Toe River (STR) Tributaries in Section R-2519A from west to east. 45

Table 15. Streams in South Toe River in R-2519B Segment from West to East. 46

Table 16. Streams in North Toe River from West to East (R-2519B). 47

Table 17. NCDOT Fish Community and Benthic Macroinvertebrate Sample Locations. 64

Table 188. On-site Stream Mitigation* for R-2518A, R-2518B, R-2519A and R-2519B. 69

Table 19. Federally Protected Species in Madison (Ma), Mitchell (Mi), and Yancey (Ya) Counties. 72

Figure 1. Project Vicinity Map 6

Figure 2. Appalachian Elktoe Critical Habitat Unit 6 24

Figure 3. Riparian Buffer Protection Areas 68

Figure 4. Virginia Spirea Element Occurrences 84