19970616 Ver 1_Complete File_20050309

_® North Carolina Wildlife Resources Commission
Richard B. Hamilton, Executive Director
MEMORANDUM
TO: wJohn Hennessy, NCDWQ
Jean Manuele, USACE
LeiLani Paugh, NCDOT
FROM: Joe Mickey, NCWRC Stream Restoration Coordinator
Jim Wasseen, Stream Restoration Technician
DATE: March 9, 2005
SUBJECT: Bare Mitigation Site, 2002 and 2004 Monitoring Report
We are pleased to submit the Bare Mitigation Site monitoring report for 2002 and 2004
for your review and files. This report is submitted as partial fulfillment of the North Carolina
Department of Transportation and North Carolina Wildlife Resources mitigation agreement for
Transportation Improvement Project R-529 BA, BB, BD, US 421 in Watauga County. This
stream mitigation work was authorized under U.S. Army Corps of Engineers permit number
199707161 and N.C. Division of Water Quality permit number 970616.
If you have questions or concerns about this monitoring report, please do not hesitate to
contact me at 336/527-1547 or 1549.
!74 2005
Aids ?sRW-H
Mailing Address: Division of Inland Fisheries • 1721 Mail Service Center • Raleigh, NC 27699-1721
Telephone; [phone] • Fax: [phone]
Bare Mitigation Site
Unnamed Tributary to Peak Creek, Ashe County
Monitoring Report
Prepared for the
NORTH CAROLINA DEPARTMENT OF TRANSPORTATION
STREAM MITIGATION PROGRAM
Transportation Improvement Project R 529 BA, BB, BD
Period covered October 22, 2002 to July 7, 2004
Joseph H. Mickey, Jr.
James A. Wasseen, II
North Carolina Wildlife Resources Commission
Division of Inland Fisheries
Raleigh
2005
This monitoring report is submitted as partial fulfillment of the off-site stream
mitigation agreement between the North Carolina Department of Transportation
(NCDOT) and North Carolina Wildlife Resources Commission (NCWRC) for the R-529
US 421 road improvement project in Watauga County. Under this agreement, a total of
14,814 linear feet of stream mitigation is required by the United States Army Corps of
Engineers (USACE) and 7,407 linear feet of mitigation is required by the North Carolina
Division of Water Quality (NCDWQ). Mickey and Scott (2002) described survey
methods, site conditions, and project objectives in the as-built report. The purpose of this
report is to summarize the monitoring data collected in 2002 and 2004 from 2183 linear
feet of an unnamed tributary to Peak Creek located on the Bare property, Ashe County
(Figure 1). Monitoring data is compared with data submitted in the 2002 as-built report
(Mickey and Scott 2002).
Monitoring
The purpose of the Bare mitigation project is to improve in-stream habitat and reduce
bank erosion from a previously channelized stream. Since construction was completed in
2001 the stream has remained a C/b4 stream type (Rosgen 1996). The as-built survey
was completed on November 8, 2001, the first and second year monitoring surveys were
completed on October 22, 2002 and on May 4, 2004. These surveys included
longitudinal profiles, channel cross-sections, pebble counts, stem counts (planted
trees/live stakes), and a photo log of the site (Appendix 1). Bankfull rain events were
monitored through review of the United States Geological Survey's South Fork New
River gage (03161000) near Jefferson, North Carolina, by photos (Appendix 1) and by
personal observations of bankfull stage stakes placed on site. Since completion of the as-
built survey (Mickey and Scott 2002) there have been seven bankfull or greater than
bankfull events at the site (Table 1). It should be noted that the fall of 2002 through 2003
was an unusually wet period. Of the seven bankfull events that occurred during this time
the storm on November 19, 2003 was the most severe. This storm dropped 6 inches of
rain in less than 8 hours on the site (personal communication, landowner). This storm
caused a new head cut channel to be created across a point bar at station 2+90 (Figure
3.2) and damaged the cattle crossing gates (Appendix 1). These damaged areas were
repaired in 2004.
Longitudinal Profile Monitoring
Since construction was completed in September 2001, several channel adjustments
have occurred to the longitudinal profile (Figure 2). The 2002 monitoring survey shows
that the stream bottom aggraded along a series of small rock vanes from stations 0+17 to
0+89, filling in the small constructed pools (Figure 2.1). In 2004 this section degraded
slightly towards post-construction elevations, however, the pools were not reestablished.
The aggrading that took place in the constructed pools in this section was not unexpected.
The rock vanes constructed in this area were an experiment to see if pools could be
created along this reach utilizing riprap placed on the streambank by the landowner years
ago. Apparently, the stream grade through this area was too low and the bed load settled
out in the constructed pools.
This monitoring report is submitted as partial fulfillment of the off-site stream
mitigation agreement between the North Carolina Department of Transportation
(NCDOT) and North Carolina Wildlife Resources Commission (NCWRC) for the R-529
US 421 road improvement project in Watauga County. Under this agreement, a total of
14,814 linear feet of stream mitigation is required by the United States Army Corps of
Engineers (USACE) and 7,407 linear feet of mitigation is required by the North Carolina
Division of Water Quality (NCDWQ). Mickey and Scott (2002) described survey
methods, site conditions, and project objectives in the as-built report. The purpose of this
report is to summarize the monitoring data collected in 2002 and 2004 from 2183 linear
feet of an unnamed tributary to Peak Creek located on the Bare property, Ashe County
(Figure 1). Monitoring data is compared with data submitted in the 2002 as-built report
(Mickey and Scott 2002).
Monitoring
The purpose of the Bare mitigation project is to improve in-stream habitat and reduce
bank erosion from a previously channelized stream. Since construction was completed in
2001 the stream has remained a C/b4 stream type (Rosgen 1996). The as-built survey
was completed on November 8, 2001, the first and second year monitoring surveys were
completed on October 22, 2002 and on May 4, 2004. These surveys included
longitudinal profiles, channel cross-sections, pebble counts, stem counts (planted
trees/live stakes), and a photo log of the site (Appendix 1). Bankfull rain events were
monitored through review of the United States Geological Survey's South Fork New
River gage (03161000) near Jefferson, North Carolina, by photos (Appendix 1) and by
personal observations of bankfull stage stakes placed on site. Since completion of the as-
built survey (Mickey and Scott 2002) there have been seven bankfull or greater than
bankfull events at the site (Table 1). It should be noted that the fall of 2002 through 2003
was an unusually wet period. Of the seven bankfull events that occurred during this time
the storm on November 19, 2003 was the most severe. This storm dropped 6 inches of
rain in less than 8 hours on the site (personal communication, landowner). This storm
caused a new head cut channel to be created across a point bar at station 2+90 (Figure
3.2) and damaged the cattle crossing gates (Appendix 1). These damaged areas were
repaired in 2004.
Longitudinal Profile Monitoring
Since construction was completed in September 2001, several channel adjustments
have occurred to the longitudinal profile (Figure 2). The 2002 monitoring survey shows
that the stream bottom aggraded along a series of small rock vanes from stations 0+17 to
0+89, filling in the small constructed pools (Figure 2.1). In 2004 this section degraded
slightly towards post-construction elevations, however, the pools were not reestablished.
The aggrading that took place in the constructed pools in this section was not unexpected.
The rock vanes constructed in this area were an experiment to see if pools could be
created along this reach utilizing riprap placed on the streambank by the landowner years
ago. Apparently, the stream grade through this area was too low and the bed load settled
out in the constructed pools.
As a result of the November 19, 2003 storm event, a major change occurred in the
longitudinal profile from stations 1+12 to 2+33 (Figure 2.1). During this storm event,
bed load materials began to deposit in the channel at station 2+33, causing a side channel
to develop across a point bar upstream at station 2+18. As this new bar channel
deepened, stream velocities were reduced in the main channel and additional streambed
materials began to be deposited in the main channel from stations 2+33 to3+30 (Figure
2.1). At station 3+30 the new bar channel connected with the main channel. From
station 3+30 to the end of the project some minor differences between the 2002 and 2004
longitudinal surveys can be noted (Figures 2.1, 2.2 and 2.3). At station 18+75 a new,
deep pool was formed and from stations 19+54 to 20+26 an existing pool was filled in by
streambed materials. These changes are a direct result of the November 19, 2003 flood
(Appendix 1). Repair work was completed on July 7, 2004 from station 2+33 to 3+30 to
reshape the point bar and eliminate the newly formed bar channel.
Cross-section Monitoring
Nine cross-sections were established during the post-construction survey and re-
surveyed during 2002 and 2004. Two additional cross-sections were added in 2004, one
to monitor a potential problem area and the other to monitor a stable pool maintained by
root wads.
CROSS-SECTION 1+78 - pool (Figure 3.1): This cross-section is located over a
long pool. There have been some changes in this cross-section profile from 2001 to 2002
as a result of the November 19, 2003 flood. The left bank has increased in height
approximately 1.4 feet near the waters edge. This is a direct result of the flood depositing
bed materials along this area. The center thalwag has been eliminated due to a 0.37 ft
rise of the mid-section of the stream channel, causing a shift in the thalwag to the left and
right banks. These changes have not caused channel instability as the banks exhibit
stable elevations and breaks in slope.
CROSS-SECTION 2+90 - pool (Figure 3.2): This cross-section is located over a
meander pool stabilized by root wads. The left and right banks have remained stable but
some major changes have occurred across the wide point bar. The November 19, 2003
flood created a 15 ft wide head cut and resulting channel across the bar from stations
0+33 to 0+48. This head cut channel does not extend all the way across the bar, but the
potential exists for it to do so over time. If this occurs the meander and pool at this
location would be eliminated. Deposition from the November 19, 2003 flood increased
the height of the bar 0.87 ft from stations 0+48 to 0+67.7 and filled in the pool at the base
of the root wads 1.07 ft. This area was repaired on July 7, 2004 by reshaping the point
bar to eliminate the new channel.
CROSS-SECTION 6+29 - pool (Figure 3.3): This is a new cross-section located
over a pool on a section of eroding bank that developed after the November 19, 2003
flood. The bank had never been a problem until this flood event. This cross-section was
established to monitor the eroding bank and to monitor repairs to the bank that were
completed on July 7, 2004.
2
CROSS-SECTION 7+19 - pool (Figure 3.4): This cross-section is located over a
pool stabilized by root wads. The post-construction and 2002 monitoring cross-section
surveys indicated no major changes in this cross-section. The 2004 survey shows a
deepening of the pool by 1.17 ft and some deposition on the point bar, a result of the
November 19, 2003 flood. Both banks exhibit the same elevations and breaks in slope
from previous surveys.
CROSS-SECTION 10+35 - riffle (Figure 3.5): This cross-section is located over a
stable riffle immediately upstream of the second livestock crossing at longitudinal profile
station 10+64. This was a wide, shallow riffle area and the purpose of this cross-section
was to monitor the natural changes in the channel once livestock were excluded from the
riparian zone. The width of the wetted perimeter indicates how much this channel has
narrowed from 2001 to 2004. The wetted perimeter decreased from 18.3 ft in 2001, to 13
ft in 2002, and to 9.2 ft in 2004. The left bank has slowly widened creating a sloping
bank, effectively narrowing the channel while the right bank has remained stable. As the
vegetation along the slope of the left bank has become established, it has trapped
materials suspended during bankfull events, effectively rebuilding the left bank with a
stable slope. A wet spring seep is located from cross-section station 0+72 to 0+75.
CROSS-SECTION 11+68 - riffle (Figure 3.6): This cross-section is located over a
riffle which has a high left bank and long, sloping point bar on the right bank. There has
been a noticeable change in the maximum height of the point bar, an increase of 0.78 ft
from the post-construction survey. This is attributed to vegetation trapping stream bed
materials during flood events. Since completion of the stream work at this cross-section,
the thalwag has aggraded by 0.45 ft. Both banks exhibit the same elevation and breaks in
slope.
CROSS-SECTION 16+81- riffle (Figure 3.7): This cross-section is located over a
riffle which has a high right bank and long, sloping point bar on the left bank. There has
been an increase in the height of the point bar by 0.53 ft and corresponding aggradations
of the streambed by 0.81 ft. While there have been some adjustments to the channel
since construction, there has been little lateral movement and the channel is stable. The
unusual elevations for post-construction station 0+03.3 and 2 year monitoring station
0+56 is attributed to incorrect rod readings due to the rod beacon having to be hand held
on the rod. This can be the only explanation for these odd elevations since the bank
profiles have not changed during the monitoring period.
CROSS-SECTION 17+08 - pool (Figure 3.8): This cross-section was added to
monitor the pool formed by root wads used to stabilize the bank. At the time of the 2004
survey, this area was not experiencing any stability problems.
CROSS-SECTION 17+57 - riffle (Figure 3.9): This cross-section is located in a
run/riffle complex below a rock weir. The tops of the banks show some ground settling
has occurred since construction. There have been some minor adjustments to the
bankfull and floodplain areas that have captured sediments during high water storm
events. There has been a 0.56 ft aggradation of the channel thalweg between post-
3
construction and year 1 monitoring. This change in thalweg elevations is a result of
stream channel adjustments following construction. The thalwag had a minor adjustment
of + 0.10 ft between year 1 and year 2 monitoring period.
CROSS-SECTION 18+42 - riffle (Figure 3.10): This cross-section monitors a stable
riffle that was not impacted by construction other than some minor grading along the top
of the right bank. This untouched riffle shows the same sediment build-up along the
banks as other cross-sections. The thalwag deepened by 0.31 ft from the year 1 to year 2
monitoring survey, bringing it back in line with the post-construction thalweg depth.
Monitoring of this site shows that the stream thalweg will increase or decrease in
elevation from year to year based on the number and magnitude of bankfull or greater
events.
CROSS-SECTION 20+80 - pool (Figure 3.11): This cross-section monitors a
constructed pool stabilized with root wads below a rock weir. The right bank has
aggraded slightly due to sediments being deposited in the bankfull and flood prone areas.
The thalwag of the pool has aggraded, reducing the depth of the pool by 0.82 ft. It will
be interesting to observe if this pool continues to fill or if it will scour out following the
next bankfull event.
These 11 cross-sections indicate that there has been no noticeable lateral movement
of the channel since construction was completed in September 2001. Most of the cross-
sections exhibit some build up of the streambanks due to deposition of materials during
storm events. These thalwag changes do not indicate an unstable channel, but a channel
bed that is constantly changing due to storm events.
Pebble Count Monitoring
Bed material analysis was conducted in a riffle at cross-section 18+42 (Figure 4).
Pavement analysis (100 sample count wetted perimeter) has changed very little from
post-construction to 2004. The D50 observed in the pavement was 16 mm, 26 mm and 27
mm for post-construction year 1, and year 2 monitoring. Since the post-construction
survey, the D50 has changed from medium gravel to coarse gravel. The D95 was 94 mm,
93 mm, and 98 mm for post-construction, year 1 and year 2 monitoring. The D95 has
remained in the small cobble particle size range. The bed material has exhibited little
change since completion of the project.
Vegetation monitoring
A total of 2,229 bare root trees and live stakes were planted in the 3.02 acre
conservation easement area during 2001-2003. The site is divided into four areas with a
total count of stems (trees and live stakes) being made in each area (Table 1). The May
2004 survey found 1,076 stems were present; a 48.3% (356.3 stems per acre) survival
rate (Table 1). The density of stems exceeds the 320 stems/acre required for woody
species planted at mitigation sites through year three (USACE 2003). It should be noted
that vegetation counts are difficult due to the small size of many of the plantings and high
4
forbs growth at the time of the stem counts. Of the 14 tree/shrub species planted, those
having a greater than 50% survival rate included silky willow Salix sericea (100%), tag
alder Alnus serrulata (100%), flowering dogwood Cornus florida (50.7%), sycamore
Platanus occidentalis (65%) and black cherry Prunus serotina (65.6%) (Table 2). The
100% survival rate for tag alder and silky willow is attributed to the high rate of natural
regeneration by these species.
Livestock Exclusion
The livestock exclusion plan includes five watering tanks, two livestock crossings and
approximately 4,400 ft of fencing. Livestock no longer have access to the riparian area
along the unnamed tributary and two small spring seeps located on the Bare property.
The two livestock crossings were damaged during the September 29, 2002 and November
19, 2003 storm events. Both crossings were repaired after each storm event. A change of
design was needed at the crossings so that flood water debris would not catch on the
fencing crossing the stream. Debris buildup on the barbed wire caused fence posts to be
pulled from their positions, resulting in the failure of the fencing across the creek. To
address this problem a removable cable system was developed that could be strung across
the stream only when cattle were rotated between pastures.
Conclusion
Monitoring data indicate that the stream channel has made minor adjustments in the
longitudinal profile and cross-sections as a result of large storm events. The stream is
stable. However, minor repairs during the fall of 2004 were required at cross-sections
2+90 and 6+29 and at the two livestock crossings. As the riparian vegetation improves,
streambank stability should continue to improve due to the exclusion of livestock from
the riparian zone. The monitoring survey will be conducted again during 2005.
References
Mickey, I H. and S. Scott. 2002. As-built report for the Bare mitigation site,
unnamed tributary to Peak Creek, Ashe County. North Carolina Wildlife
Resources Commission, Raleigh.
Rosgen, D. L. 1996. Applied river morphology. Wildland Hydrology Books. Pagosa
Springs, Colorado.
USACE (US Army Corps of Engineers), Wilmington District, U. S. Environmental
Protection Agency, North Carolina Wildlife Resources Commission, and the
North Carolina Division of Water Quality. 2003. "Stream Mitigation
guidelines". Wilmington, North Carolina.
5
Fi(iiju i. Bare stream mitigation site on an unnamed tributar} to Peak Creek. New
River drainage, Ashe County, North Carolina.

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