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ANNUAL REPORT FOR 2013 Unnamed Tributary to Smith Mill Run Wayne County TIP No. R-2554BA – Permitted Site 4 COE Action ID: SAW–200–00252 DWQ #: 20080570 Prepared By: Roadside Environmental Unit & Natural Environment Section North Carolina Department of Transportation July 2013TABLE OF CONTENTS SUMMARY........................................................................................................... 1 1.0 INTRODUCTION: ...................................................................................... 2 1.1 Project Description ......................................................................... 2 1.2 Purpose ........................................................................................ 2 1.3 Project History ............................................................................... 2 1.4 Debit Ledger ................................................................................... 2 2.0 STREAM ASSESSMENT: ......................................................................... 4 2.1 Success Criteria.............................................................................. 4 2.2 Stream Description ......................................................................... 4 2.2.1 Post-Construction Conditions.................................... 4 2.2.2 Monitoring Conditions................................................ 5 2.3 Results of Stream Assessment....................................................... 7 2.3.1 Site Data.................................................................... 7 2.4 Results of Stream and Buffer Vegetation........................................ 8 2.4.1 Description of Species............................................... 8 2.4.2 Results of Vegetation Monitoring............................... 8 2.4.3 Conclusions............................................................... 9 3.0 OVERALL CONCLUSIONS AND RECOMMENDATIONS........................ 9 4.0 REFERENCES.......................................................................................... 9 LIST OF FIGURES Figure 1 –Site Location Map ............................................................................... 3 TABLES Table 1 – Abbreviated Morphological Summary .................................................. 6 Table 2 – Vegetation Monitoring Results ............................................................. 8 APPENDICES Appendix A – Cross Section Comparisons & Longitudinal Profile Appendix B – Site Photographs, Cross Section & Photo Point Locations SUMMARY The following report summarizes the stream monitoring activities that have occurred during 2013 at the UT to Smith Mill Run Mitigation Site in Wayne County. Construction was completed in 2010 by the North Carolina Department of Transportation (NCDOT). This report provides the monitoring results for the fourth formal year of monitoring (Year 2013). The Year 2013 monitoring period is the fourth of five scheduled years for monitoring on UT to Smith Mill Run (See Success Criteria Section 2.1). Based on the overall conclusions of monitoring along UT to Smith Mill Run, the site has met the required monitoring protocols for the fourth formal year of monitoring. Based on comparing the as-built data to the monitoring data, the channel is stable at this time. A supplemental planting was completed at UT to Smith Mill Run in February 2012. The streambank and buffer are meeting the planted vegetation success criteria for the fourth year of monitoring. The longitudinal profile survey was not conducted along the stream at the UT to Smith Mill Run Mitigation Site in 2013 due to extensive vegetation growth along the channel. The heavy vegetation growth made it impossible to survey the channel without cutting down many of the desired species along the channel. NCDOT proposed to discontinue profile monitoring at the 2012 Annual Monitoring Meeting but it was agreed that a visual inspection of the channel stability throughout the reach and photo documentation at the permanent photo point locations would be completed. All other monitoring activities will continue to be completed throughout the five year monitoring period. NCDOT will continue stream monitoring at the UT to Smith Mill Run Mitigation Site for 2014. 1 1.0 INTRODUCTION 1.1 Project Description The following report summarizes the stream monitoring activities that have occurred during 2013 at the UT to Smith Mill Run Mitigation Site. The site is located adjacent to US 70 (Goldsboro Bypass) just south of SR 1313 Belfast Road in Goldsboro, NC (Figure 1). UT to Smith Mill Run Mitigation Site was constructed to provide mitigation for stream impacts associated with Transportation Improvement Program (TIP) number R-2554BA in Wayne County. The mitigation project covers approximately 1,082 linear feet of stream relocation. Construction was completed in January 2010 by the North Carolina Department of Transportation (NCDOT). Stream restoration involved the installation of rock cross vanes, rock vanes, construction of a new stream channel and construction of the floodplain to allow for overbank flooding. It also included the installation of coir fiber matting and live stakes along the streambank and bareroot seedlings in the buffer area. 1.2 Purpose In order for a mitigation site to be considered successful, the site must meet the success criteria. This report details the monitoring in 2013 at the UT to Smith Mill Run Mitigation Site. Hydrologic monitoring was not required for the site. 1.3 Project History January 2010 September 2010 Construction Completed Vegetation Monitoring (Year 1) October 2010 January 2011 August 2011 November 2011 February 2012 August 2012 Stream Channel Monitoring (Year 1) Replanted Site Vegetation Monitoring (Year 2) Stream Channel Monitoring (Year 2) Supplemental Planting Vegetation Monitoring (Year 3) December 2012 July 2013 Stream Channel Monitoring (Year 3) Vegetation and Stream Channel Monitoring (Year 4) 1.4 Debit Ledger The entire UT to Smith Mill Run stream mitigation site was used for the R-2554BA project to compensate for unavoidable stream impacts. 2 Figure 1. Site Location Map 3 2.0 STREAM ASSESSMENT 2.1 Success Criteria The stream mitigation site shall be monitored annually for five years or until success criteria are satisfied. Monitoring protocols shall follow the Monitoring Level I outlined in the Stream Mitigation Guidelines, April 2003. NCDOT will evaluate the success of the stream relocation project based on guidance provided by the Stream Mitigation Guidelines disseminated by the United States Army Corps of Engineers-Wilmington District. The survey of channel dimension will consist of permanent cross sections placed at approximately six cross sections (three riffles and three pools). Annual photographs showing both banks and upstream and downstream views will be taken from permanent, mapped photo points. The survey of the longitudinal profile will represent distinct areas of the stream and will cover a cumulative total of 1,041 linear feet of channel. The entire restored length of stream will be investigated for channel stability and in-stream structure functionality. Any evidence of channel instability will be identified, mapped and photographed. Vegetation Success For the onsite buffer mitigation sites, the permittee shall monitor the sites for five years. An annual report shall be submitted to the DWQ for a period of 5 years showing monitoring results, survival rate, success of tree and vegetation establishment, and that diffuse flow through the riparian buffer has been maintained. The first annual report shall be submitted within one year of the final planting. Failure to achieve a buffer density of 320 trees per acre after 5 years will require the annual report to provide appropriate remedial actions to be implemented and a schedule for implementation. Approval of the final annual report and a formal “close-out” of the mitigation site by the DWQ is required. The success of vegetation plantings will be measured through stem counts. Permanent quadrants will be used to sample the riparian buffer. Survival of the live stakes will be determined by visual observation throughout the 5 year monitoring period. Bareroot vegetation will be evaluated using 2 staked survival plots. Plots will be 50 ft. by 50 ft. or 100 ft. by 25 ft. and all flagged stems will be counted in those plots. Success will be defined as 320 stems per acre after 5 years. All vegetation monitoring will be conducted during the growing season. 2.2 Stream Description 2.2.1 Post-Construction Conditions The mitigation project covers approximately 1,082 linear feet of stream relocation. Construction was completed in January 2010 by the North Carolina Department of Transportation (NCDOT). Stream restoration involved the installation of rock cross vanes, rock vanes, construction of a new stream channel and construction of the floodplain to allow for overbank flooding. It also included the installation of coir fiber matting and live stakes along the streambank and bareroot seedlings in the buffer area. 4 2.2.2 Monitoring Conditions The objective of the UT to Smith Mill Run Mitigation Site relocation was to build a C5 stream type as identified in the Rosgen’s Applied River Morphology. A total of six cross sections (three in a riffle, three in a pool) were surveyed. For this report, only cross sections containing riffles were used in the comparison of channel morphology in Table 1. 5 Table 1. Abbreviated Morphological Summary (Upper and Lower Channel of the UT to Smith Mill Run) Variable Proposed Upper Reach Proposed Lower Reach Cross Section #1 (Riffle) Cross Section #3 (Riffle) Cross Section #4 (Riffle) Cross Section #6 (Riffle) Min. - Max Values (Riffle Sections Only) 2013 2013 2013 2013 2013 Drainage Area (sq. mi) 0.084 0.15 0.084 0.084 0.15 0.15 0.15 - 0.084 Bankfull Width (ft) 6.0 8.0 9.54 8.93 14.27 14 8.93 – 14.27 Bankfull Mean Depth (ft) 0.5 0.7 0.34 0.35 0.39 0.49 0.34 – 0.49 Width/Depth Ratio 12.0 11.4 28.06 25.51 36.59 28.57 25.51 – 36.59 Bankfull Cross Sectional Area (ft2) 3 5.6 3.22 3.14 5.58 6.83 3.14 – 6.83 Maximum Bankfull Depth (ft) 0.65 1.0 0.56 0.77 1.16 1.41 0.56 – 1.41 Floodprone Area (ft) 89-101 62-95 39.89 55 26 41 26 – 55 Entrenchment Ratio 14.8-16.8 7.9-11.9 4.18 6.16 1.82 2.93 1.82 – 6.16 *Drainage Area, Floodprone Width, and Slope are averaged values only. *Riffle values are used for classification purposes. 6 2.3 Results of the Stream Assessment 2.3.1 Site Data The assessment included the survey of six cross sections and the longitudinal profile of UT to Smith Mill Run Mitigation Site established by the NCDOT after construction. The length of the profile along Smith Mill Run was approximately 1,041 linear feet (Main Channel: 900 lf. and Tributary: 141 lf.). Six cross sections were established during the as-built. Cross section locations were subsequently based on the stationing of the longitudinal profile and are presented below. The location of the cross sections and longitudinal profile are shown in Appendix A. ♦ Cross Section #1. UT to Smith Mill Run, Station 166+00 linear feet, midpoint of riffle ♦ Cross Section #2. UT to Smith Mill Run, Station 251+00 linear feet, midpoint of pool ♦ Cross Section #3. UT to Smith Mill Run, Station 329+00 linear feet, midpoint of riffle ♦ Cross Section #4. UT to Smith Mill Run, Station 426+50 linear feet, midpoint of pool (main channel) and Station 64+00 linear feet, midpoint of riffle (tributary) ♦ Cross Section #5 UT to Smith Mill Run, Station 593+50 linear feet, midpoint of pool ♦ Cross Section #6 UT to Smith Mill Run, Station 805+00 linear feet, midpoint of riffle Based on comparisons of the as-built to the monitoring data, all six cross sections appear stable with little or no active bank erosion. Graphs of the cross sections are presented in Appendix A. Future survey data will vary depending on actual location of rod placement and alignment; however this information should remain similar in appearance. The longitudinal profile survey was not conducted along the stream at the UT to Smith Mill Run Mitigation Site in 2013 due to extensive vegetation growth along the channel. The heavy vegetation growth made it impossible to survey the channel without cutting down many of the desired species along the channel. NCDOT proposed to discontinue profile monitoring at the 2012 Annual Monitoring Meeting but it was agreed that a visual inspection of the channel stability throughout the reach and photo documentation at the permanent photo point locations would be completed. All other monitoring activities will continue to be completed throughout the five year monitoring period. A visual inspection of the channel and photos taken from photo points 1 through 6 showed that the channel bed is stable throughout the stream relocation at this time. 7 2.4 Results of Stream and Buffer Vegetation 2.4.1 Description of Species The following live stake species were planted on the streambank: Salix nigra, Black Willow Cornus amomum, Silky Dogwood The following tree species were planted in the buffer area: Liriodendron tulipifera, Tulip Poplar Platanus occidentalis, American Sycamore Juglans nigra, Black Walnut Betula nigra, River Birch Fraxinus pennsylvanica, Green Ash 2.4.2 Results of Vegetation Monitoring Buffer Vegetation: One 50 ft. x 50 ft. vegetation plot and one 100 ft. x 25 ft. vegetation plot were set to determine the trees per acre in the buffer area. Table 2. Vegetation Monitoring Results Plot #Tulip PoplarAmerican SycamoreBlack WalnutRiver BirchGreen AshTotal (Year 4)Total (at planting)Density (Trees/Acre)110266165864616271411624040680648Average Density (Trees/Acre) Site Notes: The black willow and silky dogwood live stakes were surviving along the streambank. A supplemental planting was completed in February 2012 due to the lower end of the site, which included Plot #1, not meeting the planted vegetation success criteria in 2011. Other vegetation noted included cattail, baccharis, sweetgum, lespedeza, soft rush, pine, and various grasses. 8 2.4.3 Conclusions There were two vegetation monitoring plots established throughout the buffer area. The 2013 vegetation monitoring of the site revealed an average tree density of 648 trees per acre. This average is above the minimum success criteria of 320 trees per acre after year four monitoring. NCDOT will continue to monitor the vegetation at the UT to Smith Mill Run Mitigation Site. 3.0 OVERALL CONCLUSIONS/RECOMMENDATIONS The UT to Smith Mill Run Mitigation Site has met the required monitoring protocols for the fourth formal year of monitoring. The channel and structures throughout the stream are stable at this time. The streambank and buffer are meeting the planted vegetation success criteria for the fourth year of monitoring. NCDOT will continue stream monitoring at the UT to Smith Mill Run Mitigation Site for 2014. 4.0 REFERENCES Natural Channel Design for UT to Smith Mill Run (Permit Site 4); Wayne County, NC, Rev. October 10, 2007. As-Built Report for Stream Restoration on R-2554BA Permit Site 4, Wayne County, NC, February 26, 2010. Rosgen, D.L, 1996. Applied River Morphology. Wildland Hydrology, Pagosa Springs, Colorado. US Army Corps of Engineers (USACE), 2003. Stream Mitigation Guidelines. Prepared with cooperation from the US Environmental Protection Agency, NC Wildlife Resources Commission, and the NC Division of Water Quality. 9 APPENDIX A CROSS SECTION COMPARISONS & LONGTITUDINAL PROFILE Cross-Section #1 (Riffle) Abbreviated Morphological Summary 2010 2011 2012 2013 2014 Bankfull Width (ft) 9.93 9.87 9.91 9.54 Bankfull Mean Depth (ft) 0.32 0.34 0.30 0.34 Width/Depth Ratio 31.03 29.03 33.03 28.06 Bankfull Cross Sectional Area (ft2) 3.18 3.4 2.93 3.22 Maximum Bankfull Depth (ft) 0.51 0.57 0.57 0.56 Width of the Floodprone Area (ft) 43 40.46 40.27 39.89 Entrenchment Ratio 3.9 4.1 4.06 4.18Cross-Section #2 (Pool) Abbreviated Morphological Summary* 2010 2011 2012 2013 2014 Bankfull Cross Sectional Area (ft2) 15.81 13.74 13.12 13.76 Maximum Bankfull Depth (ft) 2.24 2.19 2.17 2.21 Bankfull Mean Depth (ft) 0.85 0.94 0.9 0.84 Bankfull Width (ft) 18.5 14.55 14.53 16.4 * According to the Rosgen Classification of Natural Rivers floodprone width, entrenchement ratio, and width depth ratio are not measured in pool, glide, or run features. Cross-Section #3 (Riffle) Abbreviated Morphological Summary 2010 2011 2012 2013 2014 Bankfull Width (ft) 8.89 8.83 8.88 8.93 Bankfull Mean Depth (ft) 0.39 0.37 0.37 0.35 Width/Depth Ratio 22.79 23.86 24 25.51 Bankfull Cross Sectional Area (ft2) 3.46 3.24 3.3 3.14 Maximum Bankfull Depth (ft) 0.84 0.77 0.83 0.77 Width of the Floodprone Area (ft) 55 55 55 55 Entrenchment Ratio 6.19 6.23 6.19 6.16Cross-Section #4 (Main Pool) Abbreviated Morphological Summary* 2010 2011 2012 2013 2014 Bankfull Cross Sectional Area (ft2) 12.89 13.36 14.5 15.14 Maximum Bankfull Depth (ft) 1.71 1.73 1.74 1.88 Bankfull Mean Depth (ft) 0.95 0.96 0.98 0.8 Bankfull Width (ft) 13.6 13.89 14.75 19 * According to the Rosgen Classification of Natural Rivers floodprone width, entrenchement ratio, and width depth ratio are not measured in pool, glide, or run features.Cross-Section #4 (Tributary Riffle) Abbreviated Morphological Summary 2010 2011 2012 2013 2014 Bankfull Width (ft) 10.55 10.26 10.76 14.27 Bankfull Mean Depth (ft) 0.52 0.43 0.46 0.39 Width/Depth Ratio 20.29 23.86 23.39 36.59 Bankfull Cross Sectional Area (ft2) 5.47 4.41 4.91 5.58 Maximum Bankfull Depth (ft) 1.09 1.06 1.18 1.16 Width of the Floodprone Area (ft) 26 26 26 26 Entrenchment Ratio 2.47 2.53 2.42 1.82Cross-Section #5 (Pool) Abbreviated Morphological Summary* 2010 2011 2012 2013 2014 Bankfull Cross Sectional Area (ft2) 14.34 14.6 14.27 13.37 Maximum Bankfull Depth (ft) 2.55 2.43 2.19 1.94 Bankfull Mean Depth (ft) 0.9 0.91 0.99 0.84 Bankfull Width (ft) 16 16 14.36 16 * According to the Rosgen Classification of Natural Rivers floodprone width, entrenchement ratio, and width depth ratio are not measured in pool, glide, or run features.Cross-Section #6 (Riffle) Abbreviated Morphological Summary 2010 2011 2012 2013 2014 Bankfull Width (ft) 9.73 9.92 12.22 14 Bankfull Mean Depth (ft) 0.75 0.72 0.59 0.49 Width/Depth Ratio 12.97 13.78 20.71 28.57 Bankfull Cross Sectional Area (ft2) 7.28 7.1 7.26 6.83 Maximum Bankfull Depth (ft) 1.45 1.36 1.44 1.41 Width of the Floodprone Area (ft) 41 41 41 41 Entrenchment Ratio 4.21 4.13 3.35 2.93APPENDIX B SITE PHOTOGRAPHS, CROSS SECTION AND PHOTO POINT LOCATIONS Cross Section #3 at Station 4+95.6 Cross Section #7 at Station 17+75.6 UT to Smith Mill Run Photo Point #1 (Upstream) Photo Point #1 (Downstream) Photo Point #2 (Upstream) Photo Point #2 (Downstream) Photo Point #3 (Upstream) Photo Point #3 (Downstream) July 2013UT to Smith Mill Run Photo Point #4 (Upstream on Main Channel) Photo Point #4 (Downstream on Main Channel) Photo Point #4 (Upstream on Tributary) Photo Point #4 (Downstream on Tributary) Photo Point #5 (Upstream) Photo Point #5 (Downstream) July 2013UT to Smith Mill Run Photo Point #6 (Upstream) Photo Point #6 (Downstream) Vegetation Plot #1 Vegetation Plot #2 Overview Photo Looking Upstream Overview Photo Looking Downstream July 2013
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Title | Annual report for... Unnamed Tributary to Smith Mill Run, Wayne County, TIP no. R-2554BA - permitted site 4 |
Other Title | Unnamed Tributary to Smith Mill Run, Wayne County |
Date | 2013-07 |
Description | 2013 |
Digital Characteristics-A | 1.62 MB; 26 p. |
Digital Format |
application/pdf |
Related Items | http://worldcat.org/oclc/863994686/viewonline |
Pres File Name-M | pubs_serial_unnamedtributarysmithmill2013.pdf |
Full Text | ANNUAL REPORT FOR 2013 Unnamed Tributary to Smith Mill Run Wayne County TIP No. R-2554BA – Permitted Site 4 COE Action ID: SAW–200–00252 DWQ #: 20080570 Prepared By: Roadside Environmental Unit & Natural Environment Section North Carolina Department of Transportation July 2013TABLE OF CONTENTS SUMMARY........................................................................................................... 1 1.0 INTRODUCTION: ...................................................................................... 2 1.1 Project Description ......................................................................... 2 1.2 Purpose ........................................................................................ 2 1.3 Project History ............................................................................... 2 1.4 Debit Ledger ................................................................................... 2 2.0 STREAM ASSESSMENT: ......................................................................... 4 2.1 Success Criteria.............................................................................. 4 2.2 Stream Description ......................................................................... 4 2.2.1 Post-Construction Conditions.................................... 4 2.2.2 Monitoring Conditions................................................ 5 2.3 Results of Stream Assessment....................................................... 7 2.3.1 Site Data.................................................................... 7 2.4 Results of Stream and Buffer Vegetation........................................ 8 2.4.1 Description of Species............................................... 8 2.4.2 Results of Vegetation Monitoring............................... 8 2.4.3 Conclusions............................................................... 9 3.0 OVERALL CONCLUSIONS AND RECOMMENDATIONS........................ 9 4.0 REFERENCES.......................................................................................... 9 LIST OF FIGURES Figure 1 –Site Location Map ............................................................................... 3 TABLES Table 1 – Abbreviated Morphological Summary .................................................. 6 Table 2 – Vegetation Monitoring Results ............................................................. 8 APPENDICES Appendix A – Cross Section Comparisons & Longitudinal Profile Appendix B – Site Photographs, Cross Section & Photo Point Locations SUMMARY The following report summarizes the stream monitoring activities that have occurred during 2013 at the UT to Smith Mill Run Mitigation Site in Wayne County. Construction was completed in 2010 by the North Carolina Department of Transportation (NCDOT). This report provides the monitoring results for the fourth formal year of monitoring (Year 2013). The Year 2013 monitoring period is the fourth of five scheduled years for monitoring on UT to Smith Mill Run (See Success Criteria Section 2.1). Based on the overall conclusions of monitoring along UT to Smith Mill Run, the site has met the required monitoring protocols for the fourth formal year of monitoring. Based on comparing the as-built data to the monitoring data, the channel is stable at this time. A supplemental planting was completed at UT to Smith Mill Run in February 2012. The streambank and buffer are meeting the planted vegetation success criteria for the fourth year of monitoring. The longitudinal profile survey was not conducted along the stream at the UT to Smith Mill Run Mitigation Site in 2013 due to extensive vegetation growth along the channel. The heavy vegetation growth made it impossible to survey the channel without cutting down many of the desired species along the channel. NCDOT proposed to discontinue profile monitoring at the 2012 Annual Monitoring Meeting but it was agreed that a visual inspection of the channel stability throughout the reach and photo documentation at the permanent photo point locations would be completed. All other monitoring activities will continue to be completed throughout the five year monitoring period. NCDOT will continue stream monitoring at the UT to Smith Mill Run Mitigation Site for 2014. 1 1.0 INTRODUCTION 1.1 Project Description The following report summarizes the stream monitoring activities that have occurred during 2013 at the UT to Smith Mill Run Mitigation Site. The site is located adjacent to US 70 (Goldsboro Bypass) just south of SR 1313 Belfast Road in Goldsboro, NC (Figure 1). UT to Smith Mill Run Mitigation Site was constructed to provide mitigation for stream impacts associated with Transportation Improvement Program (TIP) number R-2554BA in Wayne County. The mitigation project covers approximately 1,082 linear feet of stream relocation. Construction was completed in January 2010 by the North Carolina Department of Transportation (NCDOT). Stream restoration involved the installation of rock cross vanes, rock vanes, construction of a new stream channel and construction of the floodplain to allow for overbank flooding. It also included the installation of coir fiber matting and live stakes along the streambank and bareroot seedlings in the buffer area. 1.2 Purpose In order for a mitigation site to be considered successful, the site must meet the success criteria. This report details the monitoring in 2013 at the UT to Smith Mill Run Mitigation Site. Hydrologic monitoring was not required for the site. 1.3 Project History January 2010 September 2010 Construction Completed Vegetation Monitoring (Year 1) October 2010 January 2011 August 2011 November 2011 February 2012 August 2012 Stream Channel Monitoring (Year 1) Replanted Site Vegetation Monitoring (Year 2) Stream Channel Monitoring (Year 2) Supplemental Planting Vegetation Monitoring (Year 3) December 2012 July 2013 Stream Channel Monitoring (Year 3) Vegetation and Stream Channel Monitoring (Year 4) 1.4 Debit Ledger The entire UT to Smith Mill Run stream mitigation site was used for the R-2554BA project to compensate for unavoidable stream impacts. 2 Figure 1. Site Location Map 3 2.0 STREAM ASSESSMENT 2.1 Success Criteria The stream mitigation site shall be monitored annually for five years or until success criteria are satisfied. Monitoring protocols shall follow the Monitoring Level I outlined in the Stream Mitigation Guidelines, April 2003. NCDOT will evaluate the success of the stream relocation project based on guidance provided by the Stream Mitigation Guidelines disseminated by the United States Army Corps of Engineers-Wilmington District. The survey of channel dimension will consist of permanent cross sections placed at approximately six cross sections (three riffles and three pools). Annual photographs showing both banks and upstream and downstream views will be taken from permanent, mapped photo points. The survey of the longitudinal profile will represent distinct areas of the stream and will cover a cumulative total of 1,041 linear feet of channel. The entire restored length of stream will be investigated for channel stability and in-stream structure functionality. Any evidence of channel instability will be identified, mapped and photographed. Vegetation Success For the onsite buffer mitigation sites, the permittee shall monitor the sites for five years. An annual report shall be submitted to the DWQ for a period of 5 years showing monitoring results, survival rate, success of tree and vegetation establishment, and that diffuse flow through the riparian buffer has been maintained. The first annual report shall be submitted within one year of the final planting. Failure to achieve a buffer density of 320 trees per acre after 5 years will require the annual report to provide appropriate remedial actions to be implemented and a schedule for implementation. Approval of the final annual report and a formal “close-out” of the mitigation site by the DWQ is required. The success of vegetation plantings will be measured through stem counts. Permanent quadrants will be used to sample the riparian buffer. Survival of the live stakes will be determined by visual observation throughout the 5 year monitoring period. Bareroot vegetation will be evaluated using 2 staked survival plots. Plots will be 50 ft. by 50 ft. or 100 ft. by 25 ft. and all flagged stems will be counted in those plots. Success will be defined as 320 stems per acre after 5 years. All vegetation monitoring will be conducted during the growing season. 2.2 Stream Description 2.2.1 Post-Construction Conditions The mitigation project covers approximately 1,082 linear feet of stream relocation. Construction was completed in January 2010 by the North Carolina Department of Transportation (NCDOT). Stream restoration involved the installation of rock cross vanes, rock vanes, construction of a new stream channel and construction of the floodplain to allow for overbank flooding. It also included the installation of coir fiber matting and live stakes along the streambank and bareroot seedlings in the buffer area. 4 2.2.2 Monitoring Conditions The objective of the UT to Smith Mill Run Mitigation Site relocation was to build a C5 stream type as identified in the Rosgen’s Applied River Morphology. A total of six cross sections (three in a riffle, three in a pool) were surveyed. For this report, only cross sections containing riffles were used in the comparison of channel morphology in Table 1. 5 Table 1. Abbreviated Morphological Summary (Upper and Lower Channel of the UT to Smith Mill Run) Variable Proposed Upper Reach Proposed Lower Reach Cross Section #1 (Riffle) Cross Section #3 (Riffle) Cross Section #4 (Riffle) Cross Section #6 (Riffle) Min. - Max Values (Riffle Sections Only) 2013 2013 2013 2013 2013 Drainage Area (sq. mi) 0.084 0.15 0.084 0.084 0.15 0.15 0.15 - 0.084 Bankfull Width (ft) 6.0 8.0 9.54 8.93 14.27 14 8.93 – 14.27 Bankfull Mean Depth (ft) 0.5 0.7 0.34 0.35 0.39 0.49 0.34 – 0.49 Width/Depth Ratio 12.0 11.4 28.06 25.51 36.59 28.57 25.51 – 36.59 Bankfull Cross Sectional Area (ft2) 3 5.6 3.22 3.14 5.58 6.83 3.14 – 6.83 Maximum Bankfull Depth (ft) 0.65 1.0 0.56 0.77 1.16 1.41 0.56 – 1.41 Floodprone Area (ft) 89-101 62-95 39.89 55 26 41 26 – 55 Entrenchment Ratio 14.8-16.8 7.9-11.9 4.18 6.16 1.82 2.93 1.82 – 6.16 *Drainage Area, Floodprone Width, and Slope are averaged values only. *Riffle values are used for classification purposes. 6 2.3 Results of the Stream Assessment 2.3.1 Site Data The assessment included the survey of six cross sections and the longitudinal profile of UT to Smith Mill Run Mitigation Site established by the NCDOT after construction. The length of the profile along Smith Mill Run was approximately 1,041 linear feet (Main Channel: 900 lf. and Tributary: 141 lf.). Six cross sections were established during the as-built. Cross section locations were subsequently based on the stationing of the longitudinal profile and are presented below. The location of the cross sections and longitudinal profile are shown in Appendix A. ♦ Cross Section #1. UT to Smith Mill Run, Station 166+00 linear feet, midpoint of riffle ♦ Cross Section #2. UT to Smith Mill Run, Station 251+00 linear feet, midpoint of pool ♦ Cross Section #3. UT to Smith Mill Run, Station 329+00 linear feet, midpoint of riffle ♦ Cross Section #4. UT to Smith Mill Run, Station 426+50 linear feet, midpoint of pool (main channel) and Station 64+00 linear feet, midpoint of riffle (tributary) ♦ Cross Section #5 UT to Smith Mill Run, Station 593+50 linear feet, midpoint of pool ♦ Cross Section #6 UT to Smith Mill Run, Station 805+00 linear feet, midpoint of riffle Based on comparisons of the as-built to the monitoring data, all six cross sections appear stable with little or no active bank erosion. Graphs of the cross sections are presented in Appendix A. Future survey data will vary depending on actual location of rod placement and alignment; however this information should remain similar in appearance. The longitudinal profile survey was not conducted along the stream at the UT to Smith Mill Run Mitigation Site in 2013 due to extensive vegetation growth along the channel. The heavy vegetation growth made it impossible to survey the channel without cutting down many of the desired species along the channel. NCDOT proposed to discontinue profile monitoring at the 2012 Annual Monitoring Meeting but it was agreed that a visual inspection of the channel stability throughout the reach and photo documentation at the permanent photo point locations would be completed. All other monitoring activities will continue to be completed throughout the five year monitoring period. A visual inspection of the channel and photos taken from photo points 1 through 6 showed that the channel bed is stable throughout the stream relocation at this time. 7 2.4 Results of Stream and Buffer Vegetation 2.4.1 Description of Species The following live stake species were planted on the streambank: Salix nigra, Black Willow Cornus amomum, Silky Dogwood The following tree species were planted in the buffer area: Liriodendron tulipifera, Tulip Poplar Platanus occidentalis, American Sycamore Juglans nigra, Black Walnut Betula nigra, River Birch Fraxinus pennsylvanica, Green Ash 2.4.2 Results of Vegetation Monitoring Buffer Vegetation: One 50 ft. x 50 ft. vegetation plot and one 100 ft. x 25 ft. vegetation plot were set to determine the trees per acre in the buffer area. Table 2. Vegetation Monitoring Results Plot #Tulip PoplarAmerican SycamoreBlack WalnutRiver BirchGreen AshTotal (Year 4)Total (at planting)Density (Trees/Acre)110266165864616271411624040680648Average Density (Trees/Acre) Site Notes: The black willow and silky dogwood live stakes were surviving along the streambank. A supplemental planting was completed in February 2012 due to the lower end of the site, which included Plot #1, not meeting the planted vegetation success criteria in 2011. Other vegetation noted included cattail, baccharis, sweetgum, lespedeza, soft rush, pine, and various grasses. 8 2.4.3 Conclusions There were two vegetation monitoring plots established throughout the buffer area. The 2013 vegetation monitoring of the site revealed an average tree density of 648 trees per acre. This average is above the minimum success criteria of 320 trees per acre after year four monitoring. NCDOT will continue to monitor the vegetation at the UT to Smith Mill Run Mitigation Site. 3.0 OVERALL CONCLUSIONS/RECOMMENDATIONS The UT to Smith Mill Run Mitigation Site has met the required monitoring protocols for the fourth formal year of monitoring. The channel and structures throughout the stream are stable at this time. The streambank and buffer are meeting the planted vegetation success criteria for the fourth year of monitoring. NCDOT will continue stream monitoring at the UT to Smith Mill Run Mitigation Site for 2014. 4.0 REFERENCES Natural Channel Design for UT to Smith Mill Run (Permit Site 4); Wayne County, NC, Rev. October 10, 2007. As-Built Report for Stream Restoration on R-2554BA Permit Site 4, Wayne County, NC, February 26, 2010. Rosgen, D.L, 1996. Applied River Morphology. Wildland Hydrology, Pagosa Springs, Colorado. US Army Corps of Engineers (USACE), 2003. Stream Mitigation Guidelines. Prepared with cooperation from the US Environmental Protection Agency, NC Wildlife Resources Commission, and the NC Division of Water Quality. 9 APPENDIX A CROSS SECTION COMPARISONS & LONGTITUDINAL PROFILE Cross-Section #1 (Riffle) Abbreviated Morphological Summary 2010 2011 2012 2013 2014 Bankfull Width (ft) 9.93 9.87 9.91 9.54 Bankfull Mean Depth (ft) 0.32 0.34 0.30 0.34 Width/Depth Ratio 31.03 29.03 33.03 28.06 Bankfull Cross Sectional Area (ft2) 3.18 3.4 2.93 3.22 Maximum Bankfull Depth (ft) 0.51 0.57 0.57 0.56 Width of the Floodprone Area (ft) 43 40.46 40.27 39.89 Entrenchment Ratio 3.9 4.1 4.06 4.18Cross-Section #2 (Pool) Abbreviated Morphological Summary* 2010 2011 2012 2013 2014 Bankfull Cross Sectional Area (ft2) 15.81 13.74 13.12 13.76 Maximum Bankfull Depth (ft) 2.24 2.19 2.17 2.21 Bankfull Mean Depth (ft) 0.85 0.94 0.9 0.84 Bankfull Width (ft) 18.5 14.55 14.53 16.4 * According to the Rosgen Classification of Natural Rivers floodprone width, entrenchement ratio, and width depth ratio are not measured in pool, glide, or run features. Cross-Section #3 (Riffle) Abbreviated Morphological Summary 2010 2011 2012 2013 2014 Bankfull Width (ft) 8.89 8.83 8.88 8.93 Bankfull Mean Depth (ft) 0.39 0.37 0.37 0.35 Width/Depth Ratio 22.79 23.86 24 25.51 Bankfull Cross Sectional Area (ft2) 3.46 3.24 3.3 3.14 Maximum Bankfull Depth (ft) 0.84 0.77 0.83 0.77 Width of the Floodprone Area (ft) 55 55 55 55 Entrenchment Ratio 6.19 6.23 6.19 6.16Cross-Section #4 (Main Pool) Abbreviated Morphological Summary* 2010 2011 2012 2013 2014 Bankfull Cross Sectional Area (ft2) 12.89 13.36 14.5 15.14 Maximum Bankfull Depth (ft) 1.71 1.73 1.74 1.88 Bankfull Mean Depth (ft) 0.95 0.96 0.98 0.8 Bankfull Width (ft) 13.6 13.89 14.75 19 * According to the Rosgen Classification of Natural Rivers floodprone width, entrenchement ratio, and width depth ratio are not measured in pool, glide, or run features.Cross-Section #4 (Tributary Riffle) Abbreviated Morphological Summary 2010 2011 2012 2013 2014 Bankfull Width (ft) 10.55 10.26 10.76 14.27 Bankfull Mean Depth (ft) 0.52 0.43 0.46 0.39 Width/Depth Ratio 20.29 23.86 23.39 36.59 Bankfull Cross Sectional Area (ft2) 5.47 4.41 4.91 5.58 Maximum Bankfull Depth (ft) 1.09 1.06 1.18 1.16 Width of the Floodprone Area (ft) 26 26 26 26 Entrenchment Ratio 2.47 2.53 2.42 1.82Cross-Section #5 (Pool) Abbreviated Morphological Summary* 2010 2011 2012 2013 2014 Bankfull Cross Sectional Area (ft2) 14.34 14.6 14.27 13.37 Maximum Bankfull Depth (ft) 2.55 2.43 2.19 1.94 Bankfull Mean Depth (ft) 0.9 0.91 0.99 0.84 Bankfull Width (ft) 16 16 14.36 16 * According to the Rosgen Classification of Natural Rivers floodprone width, entrenchement ratio, and width depth ratio are not measured in pool, glide, or run features.Cross-Section #6 (Riffle) Abbreviated Morphological Summary 2010 2011 2012 2013 2014 Bankfull Width (ft) 9.73 9.92 12.22 14 Bankfull Mean Depth (ft) 0.75 0.72 0.59 0.49 Width/Depth Ratio 12.97 13.78 20.71 28.57 Bankfull Cross Sectional Area (ft2) 7.28 7.1 7.26 6.83 Maximum Bankfull Depth (ft) 1.45 1.36 1.44 1.41 Width of the Floodprone Area (ft) 41 41 41 41 Entrenchment Ratio 4.21 4.13 3.35 2.93APPENDIX B SITE PHOTOGRAPHS, CROSS SECTION AND PHOTO POINT LOCATIONS Cross Section #3 at Station 4+95.6 Cross Section #7 at Station 17+75.6 UT to Smith Mill Run Photo Point #1 (Upstream) Photo Point #1 (Downstream) Photo Point #2 (Upstream) Photo Point #2 (Downstream) Photo Point #3 (Upstream) Photo Point #3 (Downstream) July 2013UT to Smith Mill Run Photo Point #4 (Upstream on Main Channel) Photo Point #4 (Downstream on Main Channel) Photo Point #4 (Upstream on Tributary) Photo Point #4 (Downstream on Tributary) Photo Point #5 (Upstream) Photo Point #5 (Downstream) July 2013UT to Smith Mill Run Photo Point #6 (Upstream) Photo Point #6 (Downstream) Vegetation Plot #1 Vegetation Plot #2 Overview Photo Looking Upstream Overview Photo Looking Downstream July 2013 |
OCLC number | 863994686 |