EEP Project Closeout Summary
EEP Project Closeout Summary Project ID & Status
-
Project Name/Number: EEP ID County: Project Type: Current Status:
Clear Creek 092 Henderson Stream Restoration 5 Years of Monitoring complete
Project Setting & Classifications
Project Timeline
Basin: Physiographic Region: Ecoregion: USGS Hydro Unit: NCDWQ Subbasin: Trout Water: Designer: Monitoring
Milestone Construction Completed As-built survey Monitoring Year-1 Monitoring Year-2 Monitoring Year-3 Monitoring Year-4 Monitoring Year-5
French Broad Mountain Blue Ridge Belt 06010105 04-03-02 No EcoLogic Associates Kimley-Horn, SEC
Date October 2002 October 2002 December 2004 December 2005 January 2007 February 2008 December 2008
Table 1. Project Restoration Components and Mitigation Assets Stream
Asset Data Drainage/Hydrology Component Clear Creek
Restoration Component Reach 1
Asset
Watershed Data and Characteristics
Ratio
DA
Stream
%
Land
Map #
Approach
Level
Ratio
Multip
Feet
SMU
Acres
WMU
P/I/E
Type
(SM)
Order
Imper
Use
303d
1
P1
R
1.00
1.00
1196
1196
-
-
P
-
44
4th
20%
Ag-Past
No
Level
Feet
SMU
Acres
WMU
R
1196
1196
1196
1196
Table 2.Asset Summary P1 = Priority I Restoration P2 = Priority II Restoration P3 = Priority III Restoration
Wetland
R= E= EI = EII = C= P=
SMU =Stream Mitigation Units WMU = Wetland Mitigation Units P/I/E = Perennial, Intermittent, Ephemeral
Page 1 of 15 Clear Creek (092) Closeout Summary
Restoration Wetland Enhancement Stream Enhancement I Stream Enhancement II Wetland Creation Preservation
E EI EII C P
Figure 1: Project Location MADISON
YANCEY
19 £ ¤
MCDOWELL BUNCOMBE
§ ¦ ¨ 240
¦ ¨ §
§ ¦ ¨
40 § ¦ ¨
R
Charlotte
RUTHERFORD
25 £ ¤
R
Raleigh
220
26
HENDERSON
§ ¦ ¨ 95
POLK
40 § ¦ ¨
TRANSYLVANIA 178 £ ¤
0
50
25 £ ¤
276 £ ¤
100
0
10
Miles
d Rd
Pl
Page 2 of 15 Clear Creek (092) Closeout Summary
Lynwood Ln
Byers Dr
Tootsie Cir N Allen Rd
Co lle
ge
Harbor Rd
Tracy Gro ve
Rd
0
0.5 Miles
Rd
1
Prepared By
Clear Creek Stream Closeout Report (2009) Henderson County, North Carolina Date 06/25/2009
la n Sugar St d Rd Fr u it nd Rd Corn R
d
t
Dana Rd
I-26
Duncan Rd
Valley St
Fruitla
ood R d
176 £ ¤
tS
Airport Rd
White Pin e
r St
d Kanuga R
Rd
B lvd
Rd
Allen Rd S
Na rv a
McCall St
St NM ain
St Halsbury Ave
Rolfe St
Fyn ch
Dr
Dr
Carson
Ciccone
Miller Ln
d
Ln
eR
lsi d
ns
Do rth y
St
Ives St
St
Ne Gi lbe r
Ga p
Rd
Whit e
Hil lvie w
o wH
d pe R
Loop Rd
d
nce R d
Allen St
ill
R Willow
W Pri
Sugarloaf Rd
n Mid Alle
Robin St
I-26
£ ¤
E
rh de
n St St w llo Wi
ro Heb
r Ho wa rd
E
4th Ave
dell D
Dr
Dania Rd
Hil
St
Ew ar t Dr
e Av
Un
Project
St llen WA
7
th
Wad
64
rk Pa
2154
5th Ave W 3rd Ave W
St
U V
Hendersonville
te Sta
Ra
ie ns
U V 1179
tc Mi
ll he
U V
d
Hebron Rd r rD
Rd
ve
oD r
r de Hy
Laurel Park
ill
St t e pl tS Ma cus
r
H
1932
9th Ave W
eA La k
Ln
Ec h
D
Ivy Ln
Elm
i ff Cl
eP ine Dr
Franci s R d
Holly St
191
t
Wh it
r
ll R Hi
25 £ ¤
dD
Lo
Dr
Nix R d
an nc Du
Pl
Pisg ah
U V Yo n
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he S Bly t
Me r ga
St
Higate Rd
Valm ont D r
eD r Na tur
d ek R
Dr
Co me tD r
Ga
Project Area
d
Hay nes
rd
p
Atw oo
1676
Brook St
n gto lin Ar
e al
1462
Prepared For
sR
pp
kd Oa
Dr
wa
r Cre
Ca
Rd
U V
Toxaway
Smyth Rd
N
Ho
dy D r
Nil e sR d
us
26 § ¦ ¨ Clea
in Mounta
Ran
Rd
Rd ee k r Cr Clea
1638
Foxwood Dr
Lo c
Ho wa rd G ll e y D ap Rd r
U V
r
d
inn
n
ook R d
M Mc
Sh e
Florida Dr Debbie D
Ste pp R
Ali ett eL
d pR de Ca m
South br
1664
Lakew
2nd St
6th St
r
n
1646
Br o oks i
Wick in sD
r Ln
D
Rd
y ad Sh
Ho lly
ton er Eg
Raymond Dr
d
I-2 6
rR
2282
rpe
Pl
Loblin L
Ove rhill Dr
U V
Rd
1674
Pl
Pj's
1675
Mt n
Ha
Pj's
Ethel Ln
U V U V U V U V
ge
eR
Bur
Glov e
Rd les
6 I-2
p Na
Miles
tG r ov
26 § ¦ ¨
20
Ball enger Rd
R
Imperial Rd
77 § ¦ ¨
74 £ ¤
26 § ¦ ¨
HAYWOOD
85 § ¦ ¨ R
Mc Murray Rd N
Winston-SalemR
Project Number 092
Background and Project History The Clear Creek restoration site is located in a relatively low slope mountain valley in Henderson County, NC. It is a fourth order tributary to Mud Creek in the French Broad River Basin. The restoration reach runs through a former overgrazed pasture between I-26 and Clear Creek Road. The watershed of this section of Clear Creek has a drainage area of approximately 44 square miles. Clear Creek is listed as Class C waters, protected for secondary recreation, fishing, wildlife, and aquatic life propagation and survival, and agriculture. There are no restrictions on watershed development activities. Prior to January 1951, the date of the oldest aerial photograph available at the Henderson County NRCS Office, Clear Creek was straightened. Presumably, it was straightened for agricultural purposes and for construction of a sanitary sewer line, as the county was predominantly rural at that time. Successive aerial photographs show the construction of I-26 in 1965. A 1969 aerial photograph (NCDOT) shows Clear Creek flowing straight, wide and shallow, typical of an F stream type. The 1994 photograph shows that Clear Creek is trying to re-establish meanders. See aerials from 2001 (pre-construction and from 2007 post-construction) in Figure 2. Shortly after construction, successive Hurricane events in 2004 generated several isolated instances of bank scour, which have advanced little over the monitoring period. The percentage of bank exhibiting scour has maintained levels between 8 and 10% since that time, with little advancement. In between the large storms related to the remnant hurricanes of 2004, the bank was hardened in an emergency measure near the old channel plug at the top of the project. The flow vectors coming into the project under the I-26 bridge led to concerns after the first event that the forecasted, second event might re-enter or avulse into the abandoned channel on stream left. The North Carolina Ecosystem Enhancement Program (EEP) always intended to regrade and replant this area once additional observation provided confidence that the vectors and conditions would not lead to an avulsion. This was carried out in winter of 2008/2009 and while equipment was already on site, another area between station 9+00 and 10+00 on stream right was repaired as well. This area did not seem to completely arrest its advancement as with the other areas of bank scour and the adjacent floodplain exhibited poorer soil conditions and lesser vegetation success. This included bank resloping and root wrap installation to an area greater than the bounds of observed instability as well as installation of additional plantings.
Page 3 of 15 Clear Creek (092) Closeout Summary
Figure 2: Pre-Post Construction Aerial Photographs
Prepared For
Project
Prepared By
Clear Creek Stream Closeout Report (2009) Henderson County, North Carolina Date
Project Number
06/25/2009
092
Page 4 of 15 Clear Creek (092) Closeout Summary
Figure 3: Project Site Map
Hyd er F arm
Nix
Rd
Rd
Nix Rd
B ur fo al
r Ci
Rd
Asset 1 ok ro
ra
nb
26 § ¦ ¨ 26 ¦ ¨ §
reek Rd
C
D
W
ay
sor C
Dr
t
Gr
Ho l
ly w
E Prepared For
oo d
in St N Ma
Azal ea
U V 1668
NM
ain
ee n
fie
ld
Ln
St
Clear Creek Rd
St
Hol
ly S
t Hy de
y Rd Berkele
Project
r
Atwood Dr
W ay
Wi nd
Pin eh urst
dD
Cle a rC
i av
es
At
o wo
0
rS
t
Page 5 of 15 Clear Creek (092) Closeout Summary
700
Feet
Prepared By
Clear Creek Stream Closeout Report (2009) Henderson County, North Carolina Date 06/25/2009
350
Project Number 092
! !
!3
¬«
100
800
- «¬¬ «
700
1
2
!1
! !
Stream Channel Profile 2008 Thalweg
Channel Structures
.
Rootwad
AsBuilt Centerline !
¬ «
As Built Permanent Photo Points As Built Vegetation Quads
J-Hook Rock Cross Vane Rock Vane 0
! As Built Cross Sections
Feet
Figure 4. Monitoring Plan View
Page 6 of 15 Clear Creek (092) Closeout Summary
10 0
As Built Restoration Area
50
11 00
0
500
¬ «
4 5
!
!2 !2
!1
600
00 10
!3
200
¬«
3
6
-«¬
-¬«
900
!4
300
!
10
¬ «
7 8
400
¬ «
¬ «
9
Clear Creek – Before Construction (2001) Figure 5: Pre-Existing Condition Photos
Page 7 of 15 Clear Creek (092) Closeout Summary
Clear Creek – Before Construction (2001)
Clear Creek – Before Construction (2001)
Clear Creek – As-Built Station 1+00 Facing Downstream
Clear Creek – Year 5 (2008) Station 1+00 Facing Downstream
Clear Creek – As-Built Station 7+80 Right Floodplain Facing Upstream
Clear Creek – Year 5 (2008) Station 7+80 Right Floodplain Facing Upstream
Clear Creek – Hurricane Frances (09/2004) Station 7+80 Facing Upstream
Clear Creek – Year 5 (2008) Station 7+80 Facing Upstream Compare to Hurricane Frances Photo
Clear Creek – Year 5 (2008) Station 5+50 Facing Upstream Note established vegetation along banks.
Figure 6: As-Built Photo Comparison Clear Creek – Hurricane Ivan (09/2004) Station 0+00 Facing Downstream
Figure 7: Stream Photos
Page 8 of 15 Clear Creek (092) Closeout Summary
Channel Stability Dimension Through the five year monitoring period, the riffle cross section areas have averaged 6% to 18% larger than the as-built conditions. A portion of this increase could be attributed to XS1 and XS2 being re-set during the monitoring year 2 morphological survey. Heavy flooding events in 2004 (see figure 6 photos of Hurricanes Ivan and Frances) generated several isolated instances of bank scour and some impact to three in-stream structures. These conditions have not noticeably advanced after their initial occurrence. The channel prior to restoration was classified as an F5 stream type, wide and shallow. The channel was constructed as a C4 stream type. The entrenchment ratio for the stream was maintained throughout the monitoring period, which indicates healthy floodplain capacity. There appeared to be some lateral migration in cross section three, but this may have been a lateral shift in the survey by the monitoring consultant. The bankfull area increased for XS1 and XS3 during monitoring year 2, however the subsequent years showed a trend towards as-built conditions. The pool cross section exhibited greater depth than that of the riffles, indicating the maintenance of distinct bedform features during the monitoring period. The project’s dimensions currently represent an E/C channel and exhibit steep inner meanders, which can present pressure on the outer meander. Some meanders have exhibited modest, slow lateral migration, but this appears to be at a sustainable rate such that the inner meander builds at a complementary modest rate. Collectively, these conditions indicate stability or stable trends of the restored reach. The plots below show some of the conditions of the channel dimensions for the project.
Eleation (ft)
Table 3. Cross-Sectional Areas Based on As-Built BKF 2078 2077 2076 2075 2074 2073 2072 2071 2070 2069 2068 2067 2066 2065 2064 0
20
40
60
Water Surface Elevation XS1-2008 Bed Elevation XS1-2007 Bed Elevation XS1-2004
80
100 120 Station (ft) Bankfull Elevation XS1-2008 Bed Elevation XS1-2006 Bed Elevation XS1-AsBuilt (2003)
Figure 8. Cross Section 1 (Riffle)
Page 9 of 15 Clear Creek (092) Closeout Summary
140
160
180
200
XS ID
MY0
MY1
MY2
MY3
MY4
MY5
Mean
XS 1
335
338
446
387
371
418
383
XS 2
352
337
361
356
358
372
356
XS 3
337
322
444
343
397
388
372
220
Bed Elevation XS1-2008 Bed Elevation XS1-2005
Cross Section 1 (Riffle) Photo (2008)
Elevation (ft)
2076 2075 2074 2073 2072 2071 2070 2069 2068 2067 2066 2065 2064 2063 2062 0
20
40
60
80 100 Station (ft)
120
140
Water Surface Elevation XS2-2008
Bankfull Elevation XS2-2008
Bed Elevation XS2-2008
Bed Elevation XS2-2007
Bed Elevation XS2-2006
Bed Elevation XS2-2005
160
180
Elevation (ft)
Figure 8. Cross Section 2 (Riffle)
Cross Section 2 (Riffle) Photo (2008)
2076 2075 2074 2073 2072 2071 2070 2069 2068 2067 2066 2065 2064 2063 2062 2061 0
20
40
60
80 Station (ft)
100
120
140
Water Surface Elevation XS3-2008
Bankfull Elevation XS3-2008
Bed Elevation XS3-2008
Bed Elevation XS3-2007
Bed Elevation XS3-2006
Bed Elevation XS3-2005
Figure 9. Cross Section 3 (Pool) Page 10 of 15 Clear Creek (092) Closeout Summary
160
180
Cross Section 3 (Pool) Photo (2008)
Profile The riffles, pools, and thalweg have maintained or improved function over the course of the five year monitoring period. Overall the bed has maintained feature faceting, but has been subject to imports of sand and as a result the thalweg has been shifting. It has generally been controlled by the project structures and woody debris that has been introduced and passed through the reach at various points in the project’s history. Pools and bed faceting have been maintained in overall quantity, but these bed features (other than those tied to the engineered structures) have oscillated in their longitudinal position in response to the above factors. Some of the variability exhibited with baseline and year-1 monitoring may vary due to a different method of survey with subsequent measurements.
2073
Clear Creek Stream Thalweg Profile
2072 2071 2070 2069
Elevation (ft)
2068 2067 2066 2065 2064 2063 2062 2061
XS-1
2060 0
100
200
XS-2 300
400
500
600
700
XS-3
800
900
1000
1100
1200
Station (ft)
Figure 10. Clear Creek Longitudinal Profile
Page 11 of 15 Clear Creek (092) Closeout Summary
Water Surface Elevation 2008
Bankfull Elevation 2008
In-Stream Structures 2008
Cross Sections 2008
Bed Elevation 2008
Bed Elevation 2007
Bed Elevation 2006
Bed Elevation 2005
Bed Elevation 2004
Bed Elevation AsBuilt
Water Surface Slope
Bankfull Slope
Water Surface Slope y=-0.0008x+2066.5 Bankfull Slope y=-0.0005x+2070.7
1300
Substrate As described previously the site has been subject to the import and presence of sand, which has contributed to a shifting thalweg and although the bed has maintained pools and a diversity of bed facets, the overlaying material is definitively finer than intended, limiting coarser riffle bedforms. XS1 – Riffle: 5 year mean – Very coarse sand (d50) to Medium gravel (d84). XS2 – Riffle: 5 year mean - Very fine gravel (d50) to Medium gravel (d84). XS3 – Pool: 5 Year Mean – Coarse sand (d50) to Fine gravel (d84).
Table 4. Project Bedform Substrate Data Cross Section 1 (Riffle)
D50 (mm)
D84 (mm)
MY0
Cross Section 2 (Riffle)
D50 (mm)
D84 (mm)
MY0
MY1
11.5
27
MY2
MY1
Cross Section 3 (Pool)
D50 (mm)
D84 (mm)
1.7
7
MY0 11.5
27
MY2
MY1 MY2
MY3
0.1
9.5
MY3
0.3
5.6
MY3
0.2
14.5
MY4
0.7
4.6
MY4
1.1
4
MY4
0.2
0.8
MY5
0.2
9.5
MY5
0.2
10.4
MY5
0.2
4.7
Average
0.3
7.9
Average
0.5
6.7
Average
0.2
6.7
Page 12 of 15 Clear Creek (092) Closeout Summary
Status of Engineered Structures Three structures designed to provide bank protection exhibited some loss of structural integrity or did not provide complete bank protection as intended. These conditions are believed to be the result of flooding events from 2004 and 2005 (See figure 6 photos of Hurricanes Ivan and Frances) and have not noticeably advanced since their initial onset. Also, associated with the flooding events of 2004 and 2005 are several isolated instances of bank scour, which have advanced little over the monitoring period. Other in-stream structures are holding grade and directing the flow into the center of the channel properly. Bankfull Events There were three recorded bankfull events during the five year monitoring period, of which occurred on 07/02/03, 09/08/04, and 10/13/08. Alluvial deposition on the floodplain can be seen in figure 11 below.
Figure 11. Evidence of Bankfull Event (10/13/2008)
Page 13 of 15 Clear Creek (092) Closeout Summary
Table 6. Project Stem Counts Stem Counts per Acre by Plot Plots
2
1 MY 1 2 3 4 5
Year 2004 2005 2006 2007 2008
Avg. (P) 1578.3 566.6 465.4 455.3 414.8
Avg. (V) N/A N/A 1112.9 2033.5 1527.7
P* 242.8 728.4 566.6 566.6 526.1
V* N/A N/A 2509.1 5746.5 4249.2
P* 2711.4 688.0 607.0 526.1 728.4
4
3 V* N/A N/A 1618.7 1983.0 1416.4
P* 809.4 202.3 202.3 202.3 121.4
V* N/A N/A 283.3 161.9 283.3
P* 2549.5 647.5 485.6 526.1 283.3
V* N/A N/A 40.5 242.8 161.9
Success criteria for the project require 260 live stems per acre within the restoration area during year 5 of a 5-year monitoring period. The data in table 5 shows that the vegetation for the Clear Creek site has met the success criteria for the monitoring period. Plot 3 contains less planted stems, but total stems including volunteers exceed success criteria. The volunteer stems greatly outnumber the planted stems in plots one and two, because of the River Birch that is colonizing on that bank. Monitoring year 1 data is also significantly higher than other years, which may have been a result of using a different form of measurement. Overall the site is showing good vegetation growth and is meeting the success criteria.
*P = Planted Stems; V = Volunteer Stems
VQ1: Vegetation Quad 1 Taken: 10/13/2008
Figure 12. Vegetation Quad Photos (Year 5)
Page 14 of 15 Clear Creek (092) Closeout Summary
VQ2: Vegetation Quad 2 Taken: 10/13/2008
VQ3: Vegetation Quad 3 Taken: 10/13/2008
VQ4: Vegetation Quad 4 Taken: 10/13/2008
Project Goals, Outcomes and Conclusions The goals for the Clear Creek Stream Restoration project were to (1) improve water quality by reducing sediment load generated by eroding banks, (2) re-establish stable channel dimension, pattern and profile to Clear Creek through the process of stream restoration, (3) restore a functioning floodplain, (4) establish a riparian buffer of woody plant species, preferably native, (5) enhance aquatic and terrestrial habitats in the stream corridor, and (6) stabilize banks to safeguard a sanitary sewer line that runs parallel to Clear Creek on the south side of the channel. Analysis of the data throughout the monitoring period indicates the project’s goals have been largely met. The stream bank conditions have been improved, thus improving water quality downstream. The channel dimension, pattern and profile are all within reasonable morphological parameters of the design specifications for the site, which were based off of reference data. The floodplain was successfully reconnected to the channel, shown by the data from the crest gage and the alluvial material that has been deposited on the floodplain over time. The vegetation on site was successful, with three of the four vegetation quads meeting the success criteria when considering only planted stem counts. The fourth vegetation quad with lower planted stem counts exceeded success criteria when considering additional volunteer stem counts. The average planted stem count for the entire site exceeded success criteria. The five year monitoring process that included annual visual assessments and geomorphic surveys indicated that the project reach was performing within established success criteria ranges. There were isolated sections of limited bank scour and some loss of structural integrity due to flooding from Hurricane Ivan and Frances in 2004. These instances have advanced little over the monitoring period. Overall the project reach continues to be stable. The geomorphic measurements are within the ranges of the design parameters. In conclusion, the characteristics of the project’s assets and their measured performance yielded the ratios listed in table 1. EEP considers the project to be on a stable trajectory and seeks regulatory closure on the assets in tables 1 and 2.
Page 15 of 15 Clear Creek (092) Closeout Summary
-
Project Name/Number: EEP ID County: Project Type: Current Status:
Clear Creek 092 Henderson Stream Restoration 5 Years of Monitoring complete
Project Setting & Classifications
Project Timeline
Basin: Physiographic Region: Ecoregion: USGS Hydro Unit: NCDWQ Subbasin: Trout Water: Designer: Monitoring
Milestone Construction Completed As-built survey Monitoring Year-1 Monitoring Year-2 Monitoring Year-3 Monitoring Year-4 Monitoring Year-5
French Broad Mountain Blue Ridge Belt 06010105 04-03-02 No EcoLogic Associates Kimley-Horn, SEC
Date October 2002 October 2002 December 2004 December 2005 January 2007 February 2008 December 2008
Table 1. Project Restoration Components and Mitigation Assets Stream
Asset Data Drainage/Hydrology Component Clear Creek
Restoration Component Reach 1
Asset
Watershed Data and Characteristics
Ratio
DA
Stream
%
Land
Map #
Approach
Level
Ratio
Multip
Feet
SMU
Acres
WMU
P/I/E
Type
(SM)
Order
Imper
Use
303d
1
P1
R
1.00
1.00
1196
1196
-
-
P
-
44
4th
20%
Ag-Past
No
Level
Feet
SMU
Acres
WMU
R
1196
1196
1196
1196
Table 2.Asset Summary P1 = Priority I Restoration P2 = Priority II Restoration P3 = Priority III Restoration
Wetland
R= E= EI = EII = C= P=
SMU =Stream Mitigation Units WMU = Wetland Mitigation Units P/I/E = Perennial, Intermittent, Ephemeral
Page 1 of 15 Clear Creek (092) Closeout Summary
Restoration Wetland Enhancement Stream Enhancement I Stream Enhancement II Wetland Creation Preservation
E EI EII C P
Figure 1: Project Location MADISON
YANCEY
19 £ ¤
MCDOWELL BUNCOMBE
§ ¦ ¨ 240
¦ ¨ §
§ ¦ ¨
40 § ¦ ¨
R
Charlotte
RUTHERFORD
25 £ ¤
R
Raleigh
220
26
HENDERSON
§ ¦ ¨ 95
POLK
40 § ¦ ¨
TRANSYLVANIA 178 £ ¤
0
50
25 £ ¤
276 £ ¤
100
0
10
Miles
d Rd
Pl
Page 2 of 15 Clear Creek (092) Closeout Summary
Lynwood Ln
Byers Dr
Tootsie Cir N Allen Rd
Co lle
ge
Harbor Rd
Tracy Gro ve
Rd
0
0.5 Miles
Rd
1
Prepared By
Clear Creek Stream Closeout Report (2009) Henderson County, North Carolina Date 06/25/2009
la n Sugar St d Rd Fr u it nd Rd Corn R
d
t
Dana Rd
I-26
Duncan Rd
Valley St
Fruitla
ood R d
176 £ ¤
tS
Airport Rd
White Pin e
r St
d Kanuga R
Rd
B lvd
Rd
Allen Rd S
Na rv a
McCall St
St NM ain
St Halsbury Ave
Rolfe St
Fyn ch
Dr
Dr
Carson
Ciccone
Miller Ln
d
Ln
eR
lsi d
ns
Do rth y
St
Ives St
St
Ne Gi lbe r
Ga p
Rd
Whit e
Hil lvie w
o wH
d pe R
Loop Rd
d
nce R d
Allen St
ill
R Willow
W Pri
Sugarloaf Rd
n Mid Alle
Robin St
I-26
£ ¤
E
rh de
n St St w llo Wi
ro Heb
r Ho wa rd
E
4th Ave
dell D
Dr
Dania Rd
Hil
St
Ew ar t Dr
e Av
Un
Project
St llen WA
7
th
Wad
64
rk Pa
2154
5th Ave W 3rd Ave W
St
U V
Hendersonville
te Sta
Ra
ie ns
U V 1179
tc Mi
ll he
U V
d
Hebron Rd r rD
Rd
ve
oD r
r de Hy
Laurel Park
ill
St t e pl tS Ma cus
r
H
1932
9th Ave W
eA La k
Ln
Ec h
D
Ivy Ln
Elm
i ff Cl
eP ine Dr
Franci s R d
Holly St
191
t
Wh it
r
ll R Hi
25 £ ¤
dD
Lo
Dr
Nix R d
an nc Du
Pl
Pisg ah
U V Yo n
" )
he S Bly t
Me r ga
St
Higate Rd
Valm ont D r
eD r Na tur
d ek R
Dr
Co me tD r
Ga
Project Area
d
Hay nes
rd
p
Atw oo
1676
Brook St
n gto lin Ar
e al
1462
Prepared For
sR
pp
kd Oa
Dr
wa
r Cre
Ca
Rd
U V
Toxaway
Smyth Rd
N
Ho
dy D r
Nil e sR d
us
26 § ¦ ¨ Clea
in Mounta
Ran
Rd
Rd ee k r Cr Clea
1638
Foxwood Dr
Lo c
Ho wa rd G ll e y D ap Rd r
U V
r
d
inn
n
ook R d
M Mc
Sh e
Florida Dr Debbie D
Ste pp R
Ali ett eL
d pR de Ca m
South br
1664
Lakew
2nd St
6th St
r
n
1646
Br o oks i
Wick in sD
r Ln
D
Rd
y ad Sh
Ho lly
ton er Eg
Raymond Dr
d
I-2 6
rR
2282
rpe
Pl
Loblin L
Ove rhill Dr
U V
Rd
1674
Pl
Pj's
1675
Mt n
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Winston-SalemR
Project Number 092
Background and Project History The Clear Creek restoration site is located in a relatively low slope mountain valley in Henderson County, NC. It is a fourth order tributary to Mud Creek in the French Broad River Basin. The restoration reach runs through a former overgrazed pasture between I-26 and Clear Creek Road. The watershed of this section of Clear Creek has a drainage area of approximately 44 square miles. Clear Creek is listed as Class C waters, protected for secondary recreation, fishing, wildlife, and aquatic life propagation and survival, and agriculture. There are no restrictions on watershed development activities. Prior to January 1951, the date of the oldest aerial photograph available at the Henderson County NRCS Office, Clear Creek was straightened. Presumably, it was straightened for agricultural purposes and for construction of a sanitary sewer line, as the county was predominantly rural at that time. Successive aerial photographs show the construction of I-26 in 1965. A 1969 aerial photograph (NCDOT) shows Clear Creek flowing straight, wide and shallow, typical of an F stream type. The 1994 photograph shows that Clear Creek is trying to re-establish meanders. See aerials from 2001 (pre-construction and from 2007 post-construction) in Figure 2. Shortly after construction, successive Hurricane events in 2004 generated several isolated instances of bank scour, which have advanced little over the monitoring period. The percentage of bank exhibiting scour has maintained levels between 8 and 10% since that time, with little advancement. In between the large storms related to the remnant hurricanes of 2004, the bank was hardened in an emergency measure near the old channel plug at the top of the project. The flow vectors coming into the project under the I-26 bridge led to concerns after the first event that the forecasted, second event might re-enter or avulse into the abandoned channel on stream left. The North Carolina Ecosystem Enhancement Program (EEP) always intended to regrade and replant this area once additional observation provided confidence that the vectors and conditions would not lead to an avulsion. This was carried out in winter of 2008/2009 and while equipment was already on site, another area between station 9+00 and 10+00 on stream right was repaired as well. This area did not seem to completely arrest its advancement as with the other areas of bank scour and the adjacent floodplain exhibited poorer soil conditions and lesser vegetation success. This included bank resloping and root wrap installation to an area greater than the bounds of observed instability as well as installation of additional plantings.
Page 3 of 15 Clear Creek (092) Closeout Summary
Figure 2: Pre-Post Construction Aerial Photographs
Prepared For
Project
Prepared By
Clear Creek Stream Closeout Report (2009) Henderson County, North Carolina Date
Project Number
06/25/2009
092
Page 4 of 15 Clear Creek (092) Closeout Summary
Figure 3: Project Site Map
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reek Rd
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Page 5 of 15 Clear Creek (092) Closeout Summary
700
Feet
Prepared By
Clear Creek Stream Closeout Report (2009) Henderson County, North Carolina Date 06/25/2009
350
Project Number 092
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100
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Stream Channel Profile 2008 Thalweg
Channel Structures
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Rootwad
AsBuilt Centerline !
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As Built Permanent Photo Points As Built Vegetation Quads
J-Hook Rock Cross Vane Rock Vane 0
! As Built Cross Sections
Feet
Figure 4. Monitoring Plan View
Page 6 of 15 Clear Creek (092) Closeout Summary
10 0
As Built Restoration Area
50
11 00
0
500
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Clear Creek – Before Construction (2001) Figure 5: Pre-Existing Condition Photos
Page 7 of 15 Clear Creek (092) Closeout Summary
Clear Creek – Before Construction (2001)
Clear Creek – Before Construction (2001)
Clear Creek – As-Built Station 1+00 Facing Downstream
Clear Creek – Year 5 (2008) Station 1+00 Facing Downstream
Clear Creek – As-Built Station 7+80 Right Floodplain Facing Upstream
Clear Creek – Year 5 (2008) Station 7+80 Right Floodplain Facing Upstream
Clear Creek – Hurricane Frances (09/2004) Station 7+80 Facing Upstream
Clear Creek – Year 5 (2008) Station 7+80 Facing Upstream Compare to Hurricane Frances Photo
Clear Creek – Year 5 (2008) Station 5+50 Facing Upstream Note established vegetation along banks.
Figure 6: As-Built Photo Comparison Clear Creek – Hurricane Ivan (09/2004) Station 0+00 Facing Downstream
Figure 7: Stream Photos
Page 8 of 15 Clear Creek (092) Closeout Summary
Channel Stability Dimension Through the five year monitoring period, the riffle cross section areas have averaged 6% to 18% larger than the as-built conditions. A portion of this increase could be attributed to XS1 and XS2 being re-set during the monitoring year 2 morphological survey. Heavy flooding events in 2004 (see figure 6 photos of Hurricanes Ivan and Frances) generated several isolated instances of bank scour and some impact to three in-stream structures. These conditions have not noticeably advanced after their initial occurrence. The channel prior to restoration was classified as an F5 stream type, wide and shallow. The channel was constructed as a C4 stream type. The entrenchment ratio for the stream was maintained throughout the monitoring period, which indicates healthy floodplain capacity. There appeared to be some lateral migration in cross section three, but this may have been a lateral shift in the survey by the monitoring consultant. The bankfull area increased for XS1 and XS3 during monitoring year 2, however the subsequent years showed a trend towards as-built conditions. The pool cross section exhibited greater depth than that of the riffles, indicating the maintenance of distinct bedform features during the monitoring period. The project’s dimensions currently represent an E/C channel and exhibit steep inner meanders, which can present pressure on the outer meander. Some meanders have exhibited modest, slow lateral migration, but this appears to be at a sustainable rate such that the inner meander builds at a complementary modest rate. Collectively, these conditions indicate stability or stable trends of the restored reach. The plots below show some of the conditions of the channel dimensions for the project.
Eleation (ft)
Table 3. Cross-Sectional Areas Based on As-Built BKF 2078 2077 2076 2075 2074 2073 2072 2071 2070 2069 2068 2067 2066 2065 2064 0
20
40
60
Water Surface Elevation XS1-2008 Bed Elevation XS1-2007 Bed Elevation XS1-2004
80
100 120 Station (ft) Bankfull Elevation XS1-2008 Bed Elevation XS1-2006 Bed Elevation XS1-AsBuilt (2003)
Figure 8. Cross Section 1 (Riffle)
Page 9 of 15 Clear Creek (092) Closeout Summary
140
160
180
200
XS ID
MY0
MY1
MY2
MY3
MY4
MY5
Mean
XS 1
335
338
446
387
371
418
383
XS 2
352
337
361
356
358
372
356
XS 3
337
322
444
343
397
388
372
220
Bed Elevation XS1-2008 Bed Elevation XS1-2005
Cross Section 1 (Riffle) Photo (2008)
Elevation (ft)
2076 2075 2074 2073 2072 2071 2070 2069 2068 2067 2066 2065 2064 2063 2062 0
20
40
60
80 100 Station (ft)
120
140
Water Surface Elevation XS2-2008
Bankfull Elevation XS2-2008
Bed Elevation XS2-2008
Bed Elevation XS2-2007
Bed Elevation XS2-2006
Bed Elevation XS2-2005
160
180
Elevation (ft)
Figure 8. Cross Section 2 (Riffle)
Cross Section 2 (Riffle) Photo (2008)
2076 2075 2074 2073 2072 2071 2070 2069 2068 2067 2066 2065 2064 2063 2062 2061 0
20
40
60
80 Station (ft)
100
120
140
Water Surface Elevation XS3-2008
Bankfull Elevation XS3-2008
Bed Elevation XS3-2008
Bed Elevation XS3-2007
Bed Elevation XS3-2006
Bed Elevation XS3-2005
Figure 9. Cross Section 3 (Pool) Page 10 of 15 Clear Creek (092) Closeout Summary
160
180
Cross Section 3 (Pool) Photo (2008)
Profile The riffles, pools, and thalweg have maintained or improved function over the course of the five year monitoring period. Overall the bed has maintained feature faceting, but has been subject to imports of sand and as a result the thalweg has been shifting. It has generally been controlled by the project structures and woody debris that has been introduced and passed through the reach at various points in the project’s history. Pools and bed faceting have been maintained in overall quantity, but these bed features (other than those tied to the engineered structures) have oscillated in their longitudinal position in response to the above factors. Some of the variability exhibited with baseline and year-1 monitoring may vary due to a different method of survey with subsequent measurements.
2073
Clear Creek Stream Thalweg Profile
2072 2071 2070 2069
Elevation (ft)
2068 2067 2066 2065 2064 2063 2062 2061
XS-1
2060 0
100
200
XS-2 300
400
500
600
700
XS-3
800
900
1000
1100
1200
Station (ft)
Figure 10. Clear Creek Longitudinal Profile
Page 11 of 15 Clear Creek (092) Closeout Summary
Water Surface Elevation 2008
Bankfull Elevation 2008
In-Stream Structures 2008
Cross Sections 2008
Bed Elevation 2008
Bed Elevation 2007
Bed Elevation 2006
Bed Elevation 2005
Bed Elevation 2004
Bed Elevation AsBuilt
Water Surface Slope
Bankfull Slope
Water Surface Slope y=-0.0008x+2066.5 Bankfull Slope y=-0.0005x+2070.7
1300
Substrate As described previously the site has been subject to the import and presence of sand, which has contributed to a shifting thalweg and although the bed has maintained pools and a diversity of bed facets, the overlaying material is definitively finer than intended, limiting coarser riffle bedforms. XS1 – Riffle: 5 year mean – Very coarse sand (d50) to Medium gravel (d84). XS2 – Riffle: 5 year mean - Very fine gravel (d50) to Medium gravel (d84). XS3 – Pool: 5 Year Mean – Coarse sand (d50) to Fine gravel (d84).
Table 4. Project Bedform Substrate Data Cross Section 1 (Riffle)
D50 (mm)
D84 (mm)
MY0
Cross Section 2 (Riffle)
D50 (mm)
D84 (mm)
MY0
MY1
11.5
27
MY2
MY1
Cross Section 3 (Pool)
D50 (mm)
D84 (mm)
1.7
7
MY0 11.5
27
MY2
MY1 MY2
MY3
0.1
9.5
MY3
0.3
5.6
MY3
0.2
14.5
MY4
0.7
4.6
MY4
1.1
4
MY4
0.2
0.8
MY5
0.2
9.5
MY5
0.2
10.4
MY5
0.2
4.7
Average
0.3
7.9
Average
0.5
6.7
Average
0.2
6.7
Page 12 of 15 Clear Creek (092) Closeout Summary
Status of Engineered Structures Three structures designed to provide bank protection exhibited some loss of structural integrity or did not provide complete bank protection as intended. These conditions are believed to be the result of flooding events from 2004 and 2005 (See figure 6 photos of Hurricanes Ivan and Frances) and have not noticeably advanced since their initial onset. Also, associated with the flooding events of 2004 and 2005 are several isolated instances of bank scour, which have advanced little over the monitoring period. Other in-stream structures are holding grade and directing the flow into the center of the channel properly. Bankfull Events There were three recorded bankfull events during the five year monitoring period, of which occurred on 07/02/03, 09/08/04, and 10/13/08. Alluvial deposition on the floodplain can be seen in figure 11 below.
Figure 11. Evidence of Bankfull Event (10/13/2008)
Page 13 of 15 Clear Creek (092) Closeout Summary
Table 6. Project Stem Counts Stem Counts per Acre by Plot Plots
2
1 MY 1 2 3 4 5
Year 2004 2005 2006 2007 2008
Avg. (P) 1578.3 566.6 465.4 455.3 414.8
Avg. (V) N/A N/A 1112.9 2033.5 1527.7
P* 242.8 728.4 566.6 566.6 526.1
V* N/A N/A 2509.1 5746.5 4249.2
P* 2711.4 688.0 607.0 526.1 728.4
4
3 V* N/A N/A 1618.7 1983.0 1416.4
P* 809.4 202.3 202.3 202.3 121.4
V* N/A N/A 283.3 161.9 283.3
P* 2549.5 647.5 485.6 526.1 283.3
V* N/A N/A 40.5 242.8 161.9
Success criteria for the project require 260 live stems per acre within the restoration area during year 5 of a 5-year monitoring period. The data in table 5 shows that the vegetation for the Clear Creek site has met the success criteria for the monitoring period. Plot 3 contains less planted stems, but total stems including volunteers exceed success criteria. The volunteer stems greatly outnumber the planted stems in plots one and two, because of the River Birch that is colonizing on that bank. Monitoring year 1 data is also significantly higher than other years, which may have been a result of using a different form of measurement. Overall the site is showing good vegetation growth and is meeting the success criteria.
*P = Planted Stems; V = Volunteer Stems
VQ1: Vegetation Quad 1 Taken: 10/13/2008
Figure 12. Vegetation Quad Photos (Year 5)
Page 14 of 15 Clear Creek (092) Closeout Summary
VQ2: Vegetation Quad 2 Taken: 10/13/2008
VQ3: Vegetation Quad 3 Taken: 10/13/2008
VQ4: Vegetation Quad 4 Taken: 10/13/2008
Project Goals, Outcomes and Conclusions The goals for the Clear Creek Stream Restoration project were to (1) improve water quality by reducing sediment load generated by eroding banks, (2) re-establish stable channel dimension, pattern and profile to Clear Creek through the process of stream restoration, (3) restore a functioning floodplain, (4) establish a riparian buffer of woody plant species, preferably native, (5) enhance aquatic and terrestrial habitats in the stream corridor, and (6) stabilize banks to safeguard a sanitary sewer line that runs parallel to Clear Creek on the south side of the channel. Analysis of the data throughout the monitoring period indicates the project’s goals have been largely met. The stream bank conditions have been improved, thus improving water quality downstream. The channel dimension, pattern and profile are all within reasonable morphological parameters of the design specifications for the site, which were based off of reference data. The floodplain was successfully reconnected to the channel, shown by the data from the crest gage and the alluvial material that has been deposited on the floodplain over time. The vegetation on site was successful, with three of the four vegetation quads meeting the success criteria when considering only planted stem counts. The fourth vegetation quad with lower planted stem counts exceeded success criteria when considering additional volunteer stem counts. The average planted stem count for the entire site exceeded success criteria. The five year monitoring process that included annual visual assessments and geomorphic surveys indicated that the project reach was performing within established success criteria ranges. There were isolated sections of limited bank scour and some loss of structural integrity due to flooding from Hurricane Ivan and Frances in 2004. These instances have advanced little over the monitoring period. Overall the project reach continues to be stable. The geomorphic measurements are within the ranges of the design parameters. In conclusion, the characteristics of the project’s assets and their measured performance yielded the ratios listed in table 1. EEP considers the project to be on a stable trajectory and seeks regulatory closure on the assets in tables 1 and 2.
Page 15 of 15 Clear Creek (092) Closeout Summary
