HomeMy WebLinkAboutB-4138WM UT to Cape Fear River - Year 2 Report
ANNUAL REPORT FOR 2021
B-4138WM UT to Cape Fear River
Harnett County
TIP No. B-4138WM
USACE Action ID: SAW-2003-00357
DWR Project #: 20091321
Prepared By:
Environmental Analysis Unit & Roadside Environmental Unit
North Carolina Department of Transportation
December 2021
TABLE 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 .................................................................................... 5
2.2.1 Post-Construction Conditions .............................................. 5
2.2.2 Monitoring Conditions ......................................................... 5
2.3 Results of the Stream Assessment ............................................................ 7
2.3.1 Site Data ............................................................................. 7
3.0 VEGETATION MONITORING .............................................................................. 8
3.1 Description of Species ............................................................................... 8
3.2 Results of Vegatation Monitoring ............................................................... 8
3.3 Conclusions ............................................................................................... 8
4.0 OVERALL CONCLUSIONS AND RECOMMENDATIONS ................................... 9
5.0 REFERENCES ..................................................................................................... 9
LIST OF FIGURES
Figure 1 – Vicinity Map .................................................................................................... 3
TABLES
Table 1 – Abbreviated Morphological Summary .............................................................. 6
APPENDICES
Appendix A – Cross Section Comparisons & Stream Gauge Data
Appendix B – Site Photographs
Appendix C – Cross Section & Photo Point Locations (As-Built Plans)
1
SUMMARY
The following report summarizes the stream monitoring activities that have occurred
during 2021 at the UT to Cape Fear River mitigation site in Harnett County. The site was
originally constructed in 2013 by the North Carolina Department of Transportation
(NCDOT). The site was designed as stream mitigation for impacts associated with the
construction of Transportation Improvement Program (TIP) number B-4138WM. Due to
significant stream instability the stream was redesigned, and remediation was completed
at the site during the fall of 2019. This report provides the monitoring results for the
second formal year of monitoring (Year 2021). The Year 2021 monitoring period is the
second of five scheduled years of monitoring (See Success Criteria Section 2.1). No
hydrologic monitoring is required for this project; however, vegetation monitoring is
required for five years.
Based on the overall conclusions of monitoring, the site has met the required monitoring
protocols for the second year of monitoring. Based on comparing the monitoring data to
the as-built, the stream channel remains stable throughout at this time. The stream bank
is vegetated for the second year of monitoring.
There are a total of two vegetation monitoring plots established within the stream buffer
area. The 2021 vegetation monitoring of the site revealed an average tree density of 581
trees per acre. This average is well above the minimum success criteria of 320 trees per
acre for Year 1 of vegetation monitoring.
NCDOT proposes to continue stream monitoring at the UT to Cape Fear River site in
2022.
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1.0 INTRODUCTION
1.1 Project Description
The following report summarizes the stream monitoring activities that have occurred
during 2021 at UT to Cape Fear River mitigation site. The site is situated directly adjacent
to the southbound lanes of NC 210/401 (see Figure 1). The site was constructed to
provide mitigation for stream impacts associated with construction of TIP number B-4138.
The site is composed of one reach of a UT to Cape Fear River.
The mitigation project includes 606 linear feet of Priority II stream restoration.
Construction was completed in fall of 2019 by NCDOT. Stream restoration involved the
installation of rock cross vanes, rock sills, rock toe protection, constructed riffles,
construction of a new stream channel, and construction of the floodplain through Priority
II restoration to allow for overbank flooding. It also included the installation of coir fiber
matting/roles along the stream banks. Live stakes were installed along the streambanks
and bareroot seedlings within the buffer area in April 2021.
1.2 Purpose
For a mitigation site to be considered successful, it must meet the success criteria. This
report details the monitoring in 2021 at UT to Cape Fear River. Hydrologic monitoring
was not required.
1.3 Project History
June 2013 Initial Stream Construction Completed
June 2014 Stream Channel Monitoring (Year 1)
December 2019 Stream Remediation Completed
February 2020 As-Built Survey Completed
November 2020 Stream Channel Monitoring (Year 1 Restart)
April 2021 Streambank Reforestation Completed
August 2021 Vegetation Monitoring (Year 1)
November 2021 Stream Channel Monitoring (Year 2)
1.4 Debit Ledger
The entire stream UT to Cape Fear River mitigation site was used for the B-4138WM
project to compensate for unavoidable stream impacts.
3
Figure 1-Vicinity Map
4
2.0 STREAM ASSESSMENT
2.1 Success Criteria
Mitigation Plan states: NCDOT shall monitor the restoration site by visual observation
for channel and bank stability and by photo documentation for the survival and the density
of the vegetation. NCDOT will monitor the site for a minimum of three years or until the
site is deemed successful.
NCDWQ Permit states: The permittee shall visually monitor the vegetative plantings to
assess and ensure complete stabilization of the mitigation stream segments. Riparian
area success shall be determined by conducting stem counts to ensure a tree survival
rate of 320 stems/acre. The monitoring shall be conducted annually for a minimum of 3
years after final planting. Photo documentation shall be utilized to document the success
of the riparian vegetation and submitted to NCDWQ in a final report within sixty (60) days
after completing monitoring. After 3 years the NCDOT shall contact NCDWQ to schedule
a site visit to “close out” the mitigation site.
ACOE Permit states: In order to compensate for permanent impacts to 608 linear feet
of stream, the permittee will perform on site mitigation consisting of approximately 608
linear feet of onsite stream restoration pursuant to the plan titled “UT to Cape Fear, Bridge
No. 46 on US 401/NC 210, Stream Mitigation Plan, TIP B-4138” dated September 2009.
Acceptance of this plan and mitigation proposal is predicted on compliance with the
following conditions:
a. The restored channel will be allowed to stabilize for one growing season prior to the
introduction of stream flow.
b. Monitoring shall continue for a minimum of five years unless the Corps determines in
writing the monitoring may be discontinued.
c. Within 60 days following completion of all channel construction and planting efforts, the
permittee will submit an as-built of the final site to the Corps.
d. Monitoring reports will be submitted to the Corps by January 31 of the year following
each monitoring year.
5
2.2 Stream Description
2.2.1 Post-Construction Conditions
The mitigation project includes 606 linear feet of Priority II stream restoration.
Construction was completed in December 2019 by NCDOT. Stream restoration involved
the installation of rock cross vanes, rock sills, rock toe protection, constructed riffles,
construction of a new stream channel, and construction of the floodplain through Priority
II restoration to allow for overbank flooding. It also included the installation of coir fiber
matting/roles along the stream banks. Live stakes will be installed along the streambanks
and bareroot seedlings within the buffer area during the dormant season between
December 2020 and March 2021.
2.2.2 Monitoring Conditions
The objective of the UT to Cape Fear River restoration was to build a E4 stream type as
identified in the Rosgen’s Applied River Morphology. A total of four cross sections were
surveyed. For this report, only the riffle cross sections were used in the comparison of
channel morphology in Table 1.
6 Table 1. Abbreviated Morphological Summary B-4138WM - Cross Sections #1 and #3 Variable Proposed As-Built Monitoring Year 1 – 2020 Monitoring Year 2 – 2021 Monitoring Year 3 – 2022 Monitoring Year 4 – 2023 Monitoring Year 5 – 2024 Cross Section #1 (Riffle) Cross Section #3 (Riffle) Cross Section #1 (Riffle) Cross Section #3 (Riffle) Cross Section #1 (Riffle) Cross Section #3 (Riffle) Cross Section #1 (Riffle) Cross Section #3 (Riffle) Cross Section #1 (Riffle) Cross Section #3 (Riffle) Cross Section #1 (Riffle) Cross Section #3 (Riffle) Drainage Area (mi2) 0.66 0.66 0.66 0.66 0.66 0.66 0.66 Bankfull Width (ft) 10.5 10.00 8.5 8.00 8.2 7.23 9.28 Bankfull Mean Depth (ft) 0.7 0.54 0.61 0.55 0.61 0.45 0.76 Width/Depth Ratio 15.2 18.52 13.93 14.55 13.44 16.07 12.21 Bankfull Cross Sectional Area (ft2) 7.5 5.42 5.23 4.39 5.00 3.24 7.07 Maximum Bankfull Depth (ft) 1.3 1.04 1.01 0.96 1.06 .90 1.27 Floodprone Area (ft) 36.0 34.89 39.84 34.79 40.88 33.11 45.0 Entrenchment Ratio 3.4 3.49 4.69 4.35 4.98 4.58 4.85 *Drainage Area, Floodprone Width, and Slope are averaged values only. *Riffle values are used for classification purposes.
7
2.3 Results of the Stream Assessment
2.3.1 Site Data
The assessment included the survey of 4 cross sections and the longitudinal profile of UT
to Cape Fear River established by the NCDOT after construction. Four cross sections
were established during the 2020 as-built survey/monitoring. Cross section locations
were subsequently based on the stationing of the longitudinal profile and are presented
below. The locations of the cross sections and longitudinal profiles are shown in Appendix
A.
Cross Section #1: UT to Cape Fear River, Station 10+89 linear feet, midpoint of
riffle
Cross Section #2: UT to Cape Fear River, Station 11+85 linear feet, midpoint of
pool
Cross Section #3: UT to Cape Fear River, Station 13+85 linear feet, midpoint of
riffle
Cross Section #4: UT to Cape Fear River, Station 15+09 linear feet, midpoint of
pool
Based on visual assessment and comparisons of the as-built to the MY2 monitoring data,
the channel and all four cross sections appear stable with little or no active bank erosion.
Graphs of the cross sections are presented in Appendix A. A survey of the longitudinal
profile was not required. However, the entire restored length of stream was investigated
for channel stability and in-stream structure functionality. Photo points 1 through 4
presented in Appendix B show continued growth and vigor of herbaceous and woody
vegetation. Based on field observations (sand deposits and wrack lines) a recent bankfull
event had occurred at the site. Pebble counts were not required per the permit conditions
and therefore were not completed. All other monitoring activities will continue to be
completed by NCDOT throughout the five-year monitoring period.
An on-site stream gauge was installed at the site in May 2020. Numerous bankfull events
were documented by the on-site stream gauge at UT to Cape Fear River during the 2021
monitoring year. A graph of the stream gauge data is presented in Appendix A.
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3.0 VEGETATION: UT to CAPE FEAR RIVER
3.1 Description of Species
The following tree species were planted on the stream bank:
Salix nigra, Black Willow
Cephalanthus occidentalis, Buttonbush
The following tree species were planted in the buffer area:
Taxodium distichum, Baldcypress
Betula nigra, River Birch
Platanus occidentalis, Sycamore
Quercus nigra, Water Oak
3.2 Results of Vegetation Monitoring
Site Notes: Other species noted included stinkweed, lespedeza, Scirpus sp., baccharis,
tear-thumb and various grasses.
3.3 Conclusions
There are a total of two vegetation monitoring plots established throughout the buffer
area. The 2021 vegetation monitoring of the site revealed an average tree density of 581
trees per acre. This average is well above the minimum success criteria of 320 trees per
acre for Year 1. Plot #BaldcypressRiver BirchSycamoreWater OakTotal (Year 1)Total (at planting)Density (Trees/Acre)1 10 10 10 7 37 45 559
2 13 13 7 6 39 44 603
581
Year 1 Average Density
(Trees/Acre)
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4.0 OVERALL CONCLUSIONS AND RECOMMENDATIONS
The UT to Cape Fear River has met the required monitoring protocols for the second
formal year of monitoring. Based on comparing the monitoring data to the as-built, the
stream channel remains stable throughout at this time. The 2021 vegetation monitoring
of the site revealed an average tree density of 581 trees per acre. This average is well
above the minimum success criteria of 320 trees per acre for Year 1.
NCDOT proposes to continue stream and vegetation monitoring at UT to Cape Fear River
mitigation site in 2022.
5.0 REFERENCES
B-4138WM On-Site Stream Mitigation Plan; Harnett County, NC, Project No. 33490.1.1,
September 2009
As-Built Report/Record Drawings for UT to Cape Fear River, Harnett County, NC,
June 29,2020.
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.
APPENDIX A
CROSS SECTION COMPARISONS
&
STREAM GAUGE DATA
Cross‐Section #1 (Riffle) Abbreviated Morphological Summary
As‐built 2020 2021 2022 2023 2024
Bankfull Width (ft) 10.00 8.00 7.23
Bankfull Mean Depth (ft) 0.54 0.55 0.45
Width/Depth Ratio 18.52 14.55 16.07
Bankfull Cross Sectional Area (ft2) 5.42 4.39 3.24
Maximum Bankfull Depth (ft) 1.04 0.96 .90
Width of the Floodprone Area (ft) 34.89 34.79 33.11
Entrenchment Ratio 3.49 4.35 4.58
Cross‐Section #2 (Pool) Abbreviated Morphological Summary
As‐built 2020 2021 2022 2023 2024
Bankfull Width (ft) 14.2 13.6 10.53
Bankfull Mean Depth (ft) 1.86 1.85 1.78
Bankfull Cross Sectional Area (ft2) 26.363 25.21 18.69
Maximum Bankfull Depth (ft) 3.37 3.18 2.72
*According to the Rosgen Classification of Natural Rivers Floodprone width, entrenchment ratio, and width
depth ratio are not measured in pool, glide, or run features
Cross‐Section #3 (Riffle) Abbreviated Morphological Summary
As‐built 2020 2021 2022 2023 2024
Bankfull Width (ft) 8.5 8.2 9.28
Bankfull Mean Depth (ft) 0.61 0.61 0.76
Width/Depth Ratio 13.93 13.44 12.21
Bankfull Cross Sectional Area (ft2) 5.23 5.00 7.07
Maximum Bankfull Depth (ft) 1.01 1.06 1.27
Width of the Floodprone Area (ft) 39.84 40.88 45
Entrenchment Ratio 4.69 4.98 4.85
Cross‐Section #4 (Pool) Abbreviated Morphological Summary
As‐built 2020 2021 2022 2023 2024
Bankfull Width (ft) 14.67 14.63 14.52
Bankfull Mean Depth (ft) 1.96 1.95 1.99
Bankfull Cross Sectional Area (ft2) 28.74 28.48 28.86
Maximum Bankfull Depth (ft) 3.17 3.07 3.07
*According to the Rosgen Classification of Natural Rivers Floodprone width, entrenchment ratio, and width depth
ratio are not measured in pool, glide, or run features
APPENDIX B
SITE PHOTOGRAPHS
UT to Cape Fear River
Photo Point #1 (Upstream) Photo Point #1 (Downstream)
Photo Point #2 (Upstream) Photo Point #2 (Downstream)
Photo Point #3 (Upstream) Photo Point #3 (Downstream)
UT to Cape Fear River
Photo Point #4 (Upstream) Photo Point #4 (Downstream)
November 2021
UT to Cape Fear River
Photo Point #1 (Upstream) Photo Point #1 (Downstream)
Photo Point #2 (Upstream) Photo Point #2 (Downstream)
Photo Point #3 (Upstream) Photo Point #3 (Downstream
August 2021
UT to Cape Fear River
Photo Point #4 (Upstream) Photo Point #4 (Downstream)
Overview Looking Upstream from Cape Fear River
August 2021
UT to Cape Fear River
Aerial Drone View Looking Downstream
November 2021
APPENDIX C
CROSS SECTION, VEGETATION PLOT & PHOTO
POINT LOCATIONS (AS-BUILT PLANS)