Gracie Creek REE 2010 - Ministry of Forests, Lands and Natural

Transcription

Gracie Creek REE 2010 - Ministry of Forests, Lands and Natural
Gracie Creek – Taylor River Watershed
Funding Source: Land Based Investment Program
Of the Forest Investment Account
Investment Number: COTFL446906
Project Number: 6906005
Routine Effectiveness Evaluation of
Gracie Creek Restoration
February 2010
\
Submitted to:
Annette Van Niejenhuis
Western Forest Products
Campbell River, BC
Submitted By:
M.C. Wright and Associates
2231 Neil Drive
Nanaimo BC
V9R 6T5
Phone/Fax: (250) 591-1056
Email: [email protected]
______________________________________________________________
M.C. Wright and Associates
Gracie Creek REE –February 2010
1
Gracie Creek REE February 2010
Routine Effectiveness Evaluation of
Gracie Creek Restoration
February 2010
Citation: Musial, B., and M.C. Wright. 2010. Routine Effectiveness Evaluation of Gracie
Creek Restoration. Unpublished Report to Western Forest Products Inc.,
Campbell River, BC.
___________________________________________________________
M.C. Wright and Associates
Gracie Creek REE 2010
2
Gracie Creek REE February 2010
Table of Contents
1.0 Introduction................................................................................................................. 4
2.0 Site History .................................................................................................................. 4
3.0 Objectives..................................................................................................................... 5
4.0 REE Performance Summary ..................................................................................... 5
5.0 Conclusion and Recommendations ........................................................................... 7
Tables:
-Table 1: Routine Effectiveness Evaulation for the Repairs Made to the Gracie Creek Restoration
Sites, February, 2010
-Table 2: Summary of Remedial Work Recommendations for Gracie Creek Reaches 1 and 2,
2010.
Figures
-Figure 1 - Location Overview
-Figure 2 - Site Overview - 2004 As-built
-Figure 3 - Upper Gracie Creek: 0+500 to 0+787 with Photos
-Figure 4 - Lower Gracie Creek: Lake to 0+500 with Photos
Photos
-Gracie Creek Photo Chronology - Main Stem
- Gracie Creek Photos - Trib. 50.1
___________________________________________________________
M.C. Wright and Associates
Gracie Creek REE 2010
3
Gracie Creek REE February 2010
1.0 Introduction
Gracie Creek is located in mid-central Vancouver Island, discharging into the West end
of Two Rivers Arm, Sproat Lake (Figure 1). Gracie Creek has a total drainage area of
23.9 km2 and is one of 8 basins with an area >500ha that drain into Sproat Lake. Gracie
Creek is a high value fish resource, principally for sockeye and coho salmon, cutthroat
trout and steelhead. This channel has been affected by past logging activities in the
area which have negatively impacted fish production in this basin.
The lakeshore area of Gracie Creek was logged in the 1940’s. The Gracie Creek Basin
is contained entirely within TFL 44. Most of the valley floor was logged in the 1960’s and
the 1970’s (Horel, 1997). Logging practices would likely have included cross-stream
yarding without riparian buffers, and the probable introduction of wood debris into the
channel (Horel, 1997). The results of past logging include a loss of riparian forest and
LWD along the channel that would naturally occur in low-gradient alluvial channels of
this size. The total area logged as of July 20, 2000 was 778 ha (Horel, 2000). The
alluvial reaches of Gracie Creek were impacted during original logging but have been
recovering with some residual impacts (Horel, 2000). This basin is one of the few areas
(outside of the Taylor basin) where there are significant lengths of alluvial channel
reaches that are sensitive to sediment deposition and erosion (Horel, 1997). An
increase in channel sediment in the main Gracie Creek channel was noted as early as
1962 from 0.4 km upstream of the Stirling Main Bridge, downstream to the outlet (Horel,
1997). However, no visible change in the overall channel position has been observed
between 1962 and 1994.
2.0 Site History
In 2000 Gracie Creek was mapped and assessed using RT-GPS technology by M. C.
Wright and Associates and Hupacasath First Nation Fisheries personnel. Assessment
of the creek revealed numerous logging related impacts. Logging impacts included
severe channel aggrading, braiding, bank erosion, infilling of pools, loss of large
conifers and loss of functional LWD required to maintain fish habitat. Channel
aggrading in Reaches 1 and 2 led to predominantly subsurface flow during low flow
periods, which isolated fry in pools and during periods of draught, causing high mortality
as pools dewatered. The aggraded habitat also caused stranding of spawning sockeye
and coho and high egg mortality from the dewatered redds.
In 2003, M.C. Wright and Associates was contracted by Weyerhaeuser Company Ltd. to
create a prescription to restore Reaches 1 and 2 of Gracie Creek (Wright, 2004). The
project received approval from the Land Based Investment Program of the Forest
Investment Account (FIA) to carry out the prescribed restoration works during the 2004
___________________________________________________________
M.C. Wright and Associates
Gracie Creek REE 2010
4
Gracie Creek REE February 2010
fisheries window (Figure 2). A follow up survey to assess the affects of the first season
of fall and winter flows was completed in the spring of 2005. Significant changes were
documented and a prescription was developed to repair the damaged areas (M.C.
Wright and Associates, 2005). Prescribed repairs were carried out during the 2005
fisheries window. Since completion of the project the channel has experience extreme
flood events (especially in the fall and winter of 2006-2007).
In 2008 Western Forest Products Ltd. requested a Routine Effectiveness Evaluation of
the Gracie Creek. The REE was limited to the effectiveness of the repairs made to the
channel in 2005 and was conducted in reaches 1 and 2 of Gracie Creek (Wright, 2008).
A second routine effectiveness evaluation was requested by Western Forest Products
Ltd. in late 2009 to determine the current condition of the restored habitat. The site
evaluation was carried out in February of 2010.
3.0 Objectives
The primary objectives of the 2004 project were to:
• Re-define the Gracie Creek mainstem to provide year round fish access to
fish habitat upstream of the Sterling Mainline Bridge.
• Eliminate water from migrating into areas unsuitable for spawning and
rearing.
• Lower the bed elevation to eliminate the loss of eggs and fry caused by
frequent dewatering of spawning and rearing habitat.
The objectives of the 2005 restoration project were to;
• Repair riffles,
• Remove ineffective structures (cutbanks),
• Stabilize and redefine any unstable or eroded banks,
• Lower the channel bed elevation where significant aggrading occurred,
• Modify the log jam located immediately downstream of 0+000 to allow
sediment transport out of the system.
The Gracie Creek channel downstream of the bridge was evaluated during the 2010
REE to determine if the site has undergone any significant changes since the 2008
assessment.
4.0 REE Performance Summary
All restoration works and repairs were evaluated for physical performance (Table 1)
using the following definitions, modified from the 2003 REE guidelines:
___________________________________________________________
M.C. Wright and Associates
Gracie Creek REE 2010
5
Gracie Creek REE February 2010
Score
4
3
2
1
Condition
Remedial works have exceeded expectations and objectives
Remedial works are meeting expectations and objectives.
Remedial works are failing to meet objectives
Remedial works fail to meet objectives. Expectations are not met.
For the Gracie Creek channel downstream of the bridge (sites listed in Table 1), the
mean physical performance objective was 2.1; identified issues include:
 Backwatering from Sproat Lake has resulted in slower flows and the deposition
of a significant amount of material at the creek mouth and lower section of the
mainstem (Figures 4 and 5a).
o Observations from October of 2009 showed that downstream channel
aggradations and resultant gravel plugs blocked surface flows and
inhibited fish passage upstream (Kim Hyatt Personal Communication,
2009). This problem has been compounded by significant sediment
loading from of tributary 50.1 (See Gracie Creek Photo Chronology-Trib.
50.1).
o Figure 5a.shows aggrading in lower Gracie Creek at cross section #2, with
a loss of ~2m of channel depth (see Figure 2 for cross-section location).
 A number of sites along the channel have experienced erosion above and behind
the riprap bank armor during high flows.
o The most severe of these sites is located at the site of the old cutbank #4
where flows have eroded a large section of the bank (~3m) behind the
riprap amour (Figure 2 - Photo station 1659).
 Additionally, a second channel has branched off of tributary 50.1 and ends in a
braided section near the Gracie Creek mainstem.
o A large amount of material has been transported by this new channel that
is currently deposited at this braided area <50m from the Gracie
Mainstem.
o Should this channel breach into the mainstem it will result in additional
sediment loading and channel aggrading of the lower reach.
o Evidence of water seeping out from this new channel is visible in the
destabilized right bank section of Gracie Creek just upstream of tributary
50.1 (Figure 3, Photo station 1209).
When compared to the 2008 assessment, no significant changes were observed during
the 2010 REE. Many of the issues identified in the channel have existed since the time
of the 2008 REE, indicating that the channel has stabilized such that remedial works
can now be carried out (see Gracie Creek Photo Chronology-Main stem). Channel
cross sections showed that areas of the lower channel have aggraded (Figure 5a) while
much of the channel has stabilized (Figure 5b and c). From initial survey data it appears
that significant aggrading has also occurred in the pool at cross section 6 (Figure 5b),
however, a new pool has developed just upstream of the cross section. The profile at
___________________________________________________________
M.C. Wright and Associates
Gracie Creek REE 2010
6
Gracie Creek REE February 2010
cross section 9 was found to be very similar to that from 2004, with a well-developed
gravel bar and deepened section along the right bank (Figure 5c).
5.0 Conclusion and Recommendations
Since the restoration works were completed in 2004/2005 the channel has experienced
extreme flood events, which have impacted the constructed works. Flows have eroded
the channel banks behind the riprap amour and sediment inputs from tributary 50.1 are
causing significant channel aggrading. Sediment transport from tributary 50.1 must be
addressed as soon as possible to stop further channel aggrading in the lower reach of
Gracie Creek. In its present state fish passage from Sproat Lake is impeded during low
flow periods.
These issues indicate that the channel is currently not meeting expectations and
objectives in some of the channel sections. The following remedial works are required:
 Investigate sediment sources in tributary 50.1 (and the new secondary channel)
and develop a prescription to stop sediment loading in the Gracie Creek
Mainstem
 Develop a prescription to address the channel aggrading in the mainstem below
tributary 50.1 and at the creek mouth
 Develop a prescription to address bank erosion and instabilities at (Figures 2, 3
and 4):
 0+100-150 = left bank
 0+230 = left bank cut bank
 0+250 = right bank
 0+300-350 = left bank and right bank
 0+350-400 = right bank
 0+400-450 = right bank
 0+450 = left bank
 0+500 = left bank
 0+550= left bank
 0+550-600 = right bank
 0+600-650 = right bank
 Develop a prescription to lengthen the existing, or install a second groyne
upstream of the bridge to provide better bank protection.
 LWD should also be added to the channel to increase habitat complexity.
Remedial works are summarized in Table 2. Monitoring of the project should continue
to ensure that the project is meeting expectations and objectives. Recommended
remedial works should be carried out in 2010.
___________________________________________________________
M.C. Wright and Associates
Gracie Creek REE 2010
7
Gracie Creek REE February 2010
6.0 References:
Horel, G. 1997. Coastal Watershed Assessment (CWAP) of Sproat Lake Watershed.
Report prepared by Ostapowich Engineering Services Ltd. for MacMillan Bloedel,
Alberni West Division.
Horel, G. 2000. Sproat Lake Watershed. Update of Watershed Assessment (CWAP)
Report prepared by Ostapowich Engineering Services Ltd. for Weyerhaeuser
West Island Timberlands, Sproat Lake Operation.
Hyatt, Kim. Department of Fisheries and Oceans. Personal Communication, Oct. 2009.
M.C. Wright and Associates. 2005. Gracie Creek Restoration Project 2005. As-Built
Report.
Wright, M.C. 2004. Prescription to Rehabilitate Reaches 1 and 2 of Gracie Creek and
the Gracie Creek Side-Channel, 2003-2004.
Wright, M.C. 2008. Routine Effectiveness Evaluation of Gracie Creek Restoration.
Unpublished Report to Western Forest Products, Campbell River.
___________________________________________________________
M.C. Wright and Associates
Gracie Creek REE 2010
8
Gracie Creek REE February 2010
-Tables-
___________________________________________________________
M.C. Wright and Associates
Gracie Creek REE 2010
9
Table 1. Routine Effectiveness Evaluation for the Repairs made to the Gracie Creek Restoration sites, February 2010.
Survey CrewM. Wright, M. Sandford, B. Musial
Weather / Flow: light rain/moderate
Other Components:
Photo Numbers
Maintenance
Reccommendation
Low Flow Function
High Flow Function
Structural Stability
Structural Condition
Overall Rating
Incubation
Spawning
Overwinter
Rearing
Life Stage
Species
Access
Off-channel
Overall
Performance Objectives
Biological
Physical
Nutrient
Site
Objective
Cover
Structure
Type
Bank Protection
ID. #
Thalwag Development
Distance (m)
litated Reaches of Gracie Creek 2005
Watershed: Sproat Lake
sub-Watershed:
Pool Formation
Stream
Project Name:
Riffle
Western Forest
Name of Spons Products Inc.
REE Interval: 2.5
Forest District: South Island Forest District
Comments
Gracie Creek
Lake 50 0
GRAV
Maintain Flow
3
1
4
4
3
2
2
Creek mouth was observed to be dry on October
17th due to significant aggredation
Gracie Creek
0-50
LWD-A
Modify Log
Jam
2
2
4
4
3
2
3
Large LWD tree in center of channel could be realigned to create better flow and channel scour
Gracie Creek
50-100
RR
Bank
Protection (RB)
2
3
3
2
3
3
High flow scour above riprap along right bank.
This area aggrading from 50.1 sediment input.
Gracie Creek
100-150
RR
Bank
Protection (RB)
2
3
3
2
3
3
Pool forming along right bank, some aggrading
along left side of channel.
Gracie Creek
150-200
RR
Bank
Protection (RB)
2
3
3
2
3
3
High flow scour above riprap along right bank.
Gracie Creek
200-250
CUTBANK
Cutbank #2
(LB)
1
1
1
1
2
Cutbank has completely collapsed and eroded
along the left bank.
Gracie Creek
250-300
RR
Bank
Protection (RB)
2
3
3
2
3
3
Some scour above riprap.
Gracie Creek
300-350
RR
Bank
Protection (RB)
2
3
3
2
3
3
High flow scour above and behind riprap along
right bank. Well-developed gravel bar along left
bank.
Gracie Creek
350-400
WEIR
Rock Weir
(trib 50.1)
1
2
1
2
1
Well-developed gravel bar along left bank.
Tributary 50.1 weir failed and a lot of sediment
input into main channel.
1
2
2
1
2
2
Severe erosion (3-5m) behind riprap along left
bank. Right bank destabilization from water
breaching out of 50.1.
1
Gracie Creek
400-450
RR
Bank
Protection (RB)
Gracie Creek
450-500
RR
Bank
Protection (RB)
2
3
3
2
3
2
Erosion behind left bank riprap at location of
original cutbank 4.
Gracie Creek
500-550
RR
Bank
Protection (RB)
3
4
4
3
4
3
Riprap armour is in good condition, little erosion.
Gracie Creek
550-600
RR
Bank
Protection (RB)
2
4
4
3
4
2
Scour along left bank.
Gracie Creek
600-650
BIO-BANK
Bank
Stabilization
2
2
2
2
3
2
Right bank erosion and slumping-consider
riparian prescription
Gracie Creek
650-700
RR
Bank
Protection (RB)
3
4
4
3
4
3
Riprap armour in good condition with little erosion.
Gracie Creek
700-800
700-800
RR
RIFF
Bank
Protection (RB)
Rock Riffle
3
4
4
4
4
3
4
4
4
3
4
700-800
BLD-G
Rock Gryone
2
4
4
2
3
2
Riprap armour in good condition with little erosion.
Riffle in good condition and functioning.
Another groyne should be installed to direct flow
under the bridge.
Gracie Creek
4
2
Table 2. Summary of remedial work recommendations for Gracie Creek Reaches 1 and 2, 2010.
Priority
Watershed
Distance
1
Gracie Creek 0+350 to 0+400
2
Site ID
Maintenance
score
Trib. 50.1
1
Gracie Creek -50 to 0+000
-50
2
3
Gracie Creek 0+450 to 0+500
500
2
4
Gracie Creek 0+787
2
5
Gracie Creek 0+50 to 0+550
787
Throughout
Channel
3
Remedial works proposed
Estimated
Cost
Look into feasability of diverting
flows back into Creek #51
~$40,000
(Historic Path) and develop a
(Prescription
prescription
and Diversion)
Excavate aggraded bed
material downstream of the log
jam
$2,500.00
Install additional rip rap at
erosion zone along left bank
behind existing armour
$3,000.00
Lengthen existing or install a
second groyne upstream of the
bridge
$3,000.00
Develop a rescription to repair
scour behind riprap armour.
$10,000.00
Total Person
days
Equipment
required
Prescription
required
~25
1 x 20 ton
excavator
1x rock truck
Yes
1
1 x 20 ton
excavator
No
1
1 x Spider hoe
No
1
1 x 20 ton
excavator
No
2-3
1 x Spider hoe
No
Gracie Creek REE February 2010
-Figures-
___________________________________________________________
M.C. Wright and Associates
Gracie Creek REE 2010
10
Sproat Lake
Gracie Creek
Two Rivers
Arm
Port Alberni
0
0.5
1
T_LAKE
CHANNEL
T_STREAM
2
3
Legend
tctrl
HWY
BRIDGE
4
Kilometers
trivr
tlake
troad
SCALE:
Survey Datum: NAD 83, UTM Z10
Map Base: Devloped from Digital TRIM
Locations recorded with
TRIMBLE Pro-XR
1:34,725
Gracie Creek Routine Effectiveness Evaluation
Figure 1: Location Overview
Prepared For: Western Forest Products
Annette Van Niejenhuis
Prepared By:
M.C. Wright & Associates
February, 2010
2%
en
b
fal
ls
(
ba
rri
er
)
wo
od
Gracie Creek
Sproat Lake
Three Rivers
Arm
SHEET #1 Gracie Creek
As-built Survey 2004
backwater inlet from lake
10
10
62
51
16
63
0+
0
00
Note: as-built chainages start at 0+000 at the DS end of works,
and increase US towards the mainline road bridge.
The chainage of the center of this bridge is aprox 0+740.
Xs
ec
#1
+0
(0
Note that the design chainages were reversed (increasing DS),
and the old bridge chainage was aprox 0+250.
)
09
0
05
0+
Xs
ec
#2
(0
+0
58
)
0+10
0
16
52
SHEET #2
Gracie Creek
As-built
Survey 2004
1060
Xsec #3 (0+132)
0+150
cutbank #1
1837
Xsec #4
(0+170
)
0+
20
0
1653
20
04
)
cutbank #2
Au
g
0
25
16
5
Xs
ec
#6
(
4
6)
3)
d
7 (0
+32
0
104
57
16
0+
40
16
56
0
0
se
9
ec
#8
(0+
3
56
)
cutbank #3
c
#9
(0
+3
87
)
1056
ec
Xs
#1
58
34
)
30
0+35
X
16
ec
#
Xs
0+45
(0
+2
braid
e
SP "A"
26
#5
0+
as
-b
uil
165
5
Gr
ac
ie
1065
730
Xs
Cr
ee
k
SHEET #3 Gracie
Creek As-built Survey
2004
0+
ec
0
t(
1066
Xs
8
0+
1067
10
5
0+02
0
0
(0
Tributary 50.1 bed elevation lowered ~1m.
and 3 riffles constructed @ chainages: 20, 100 & 157m
+4
60
top of bank (typ)
)
10
4
7
bo
tto
m
of
ba
nk
(ty
p
)
0+
50
0
cutbank #4
ry
ta
bu
tri
rip rap channel armouring (typ)
60
16
Xs
ec
11
)
"
"B
12
18
cutbank #5
.1
50
SP
16 #11 (
59 0+5
od
flo
2
#1
ec
cutbank #6
constructed riffle crest (typ)
0+
Xs
10
0
0
55
0+
n
an
ch
el
)
45
+5
(0
60
0+
6
16
0
2
3 (0
1
#1
166
ec
Xs
+5
97
)
Xs
4
#1
ec
16
(0
63
0
65
0+
)
37
+6
0+157
reach break 1
731
Xs
0
end of works on tributary 50.1
(at aprox chainage 0+180)
5(
ec
Xs
#1
70
ec
0+
0+
67
5)
+6
(0
)
89
#17
+7
(0
(0+
18
c#
64
16 702)
e
Xs
ec
Xs
53
10
6
#1
5
72
0+
65
16
23
)
Xsec #19 (0+78
7)
0
15
30
rock groyne installed to deflect flows
5%
60
90
SCALE: 1:2,500
120
Meters
Gracie Creek Routine Effectiveness Evaluation
Legend
Figure 2 - Gracie CreekOverview and Chainages
gracie4c.dwg Polyline
AB_GLIDE
AB_RIPRA
GLIDE
ROAD
Layer
AB_LWD
AB_TEXT
GRAV_BAR
STANDPIP
AB_CHANB
AB_PHOTO
AB_XSEC
G_GLIDE
SURVEY
AB_CONTR
AB_POOL
BRIDGE
POOL
T_LAKE
AB_CUTBA
AB_RIFFL
CHANNEL
RIFFLE
UL
Prepared For: Western Forest Products
Annette Van Niejenhuis
Prepared By:
Survey Datum: NAD 83, UTM Z10
Map Base: Digital TRIM
Locations recorded with
TRIMBLE Pro-XR
M.C. Wright & Associates
February, 2010
1655
1440
Gracie Creek
Sproat Lake
Two Rivers
Arm
Riprap along channel
bend downstream
1199
1057
1657
1196
!
? 1057
!
?
1655
!
?
Close-up of severe erosion behind
left bank riprap
Severe erosion behind
left bank riprap
1659
1209
!
?
1196
1064
!
?
1657
1056
1440
Erosion and channel widening
1209
1661
!
?
1659
Scour along left bank downsrteam
Downstream of bridge 1230
1055
Right bank destabilized
from secondary channel
1659
1193
1054
Downstream of bridge 1664
!
?
1193
ta r y
1664
u
Trib
1193
1230
5 0.
Riffle and left bank
downstream of the bridge
1661
1662
781
!
?
1053
1
Erosion on right bank downstream
1193
Erosion on right bank across channel
-
1664
mid bridge ds
Groyne and extensive left bank
gravel bar upstream of bridge
1230
!
?
!
?
Erosion on right bank upstream
1050
1665
1051
Right bank downstream of bridge
0
30
60
120
180
240
Meters
SCALE: 1:1,500
Gracie Creek Routine Effectiveness Evaluation
Legend
Figure 3- Upper Gracie Creek: 0+500 to 0+787
Bridge
Cascade
h
H
Photo Stations
troad
Riffle
Glide
!
?
Benchmarks
Groyne
Pool
DigitizedStreams
Prepared For: Western Forest Products - Annette Van Niejenhuis
Survey Datum: NAD 83, UTM Z10
Map Base: Devloped from Digital TRIM
Locations recorded with a TRIMBLE Pro-XR
Prepared By: M.C. Wright & Associates
February, 2010
Gracie Creek
Sproat Lake
Three Rivers
Arm
Sproat Lake
Two Rivers
Arm
1208
Looking upstream to log jam
1208
1208
1063
? 1062
!
? !
Looking downstream to right
bank gravel bar from the log jam
Log jam downstream of
BMs 1062 and 1063
1652
!
?
1061
Looking downstream toward
LWD tree in channel
1652
1652
!
?
1653
1060
Looking upstream
Looking downstream
810
1653
!
?
1059
1653
Eroding left bank at original
site of cutbank 2
987
Looking upstream
!
?
Riprap along channel bend
and gravel bar upstream
1223
1058
1058
810
987
987
1655
Slumping right bank and
location of Cross Section 6
Riprap along channel
bend downstream
1199
1057
1196
-
St
re
am
#5
1
!
? 1057
!
?
1655
Looking downstream
1196
0
!
?
12.5
25
50
75
SCALE: 1:1,500
100
Meters
Legend
Gracie Creek Routine Effectiveness Evaluation
Figure 4 - Lower Gracie Creek Lake to 0+500
Riffle
troad
h
H
Photo Stations
Cascade
tlake
!
?
Benchmarks
Glide
DigitizedStreams
Pool
Prepared For: Western Forest Products
Annette Van Niejenhuis
Prepared By:
Survey Datum: NAD 83, UTM Z10
Map Base: Digital TRIM
Locations recorded with
TRIMBLE Pro-XR
M.C. Wright & Associates
February, 2010
Figure 5: Corss Sectional Profiles at Selected Sites to Demonstrate Changes in Bed Profile Since the 2004 As-built Survey.
A.
Cross Section 2, As-built 2004
Cross Section 2, February 2010
35
34
Elevation (m)
Elevation (m)
33
32
31
30
29
28
27
26
25
0
1.7
4.2
6
8.1
10.3
13
15.4
18.3
21.3
35.000
34.000
33.000
32.000
31.000
30.000
29.000
28.000
27.000
26.000
25.000
24
0
Distance (m)
B.
Right Bank
Left Bank
5
10
Cross Section 6, As-built 2004
Elevation (m)
34
Elevation (m)
33
32
31
30
29
28
27
26
25
2
5.2
8.2
10.6
12.8
14
19.5
24.7
25.5
27.3
32.1
35.000
34.000
33.000
32.000
31.000
30.000
29.000
28.000
27.000
26.000
25.000
39
Left Bank
0
Distance (m)
C.
5
10
Elevation (m)
Elevation (m)
33
32
31
30
29
28
27
26
25
3.5
5.4
7.2
10
Distance (m)
15
20
25
30
35
40
Cross-section 9, February 2010
34
0.5
30
Right Bank
Cross Section 9, As-built 2004
0
25
Distance along channel (m)
35
0
20
Cross Section 6, February 2010
35
0
15
Distance Along Channel (m)
14.4
15.6
17.2
19.7
21
35.000
34.000
33.000
32.000
31.000
30.000
29.000
28.000
27.000
26.000
25.000
Left Bank
0
Right Bank
5
10
15
Distance along channel (m)
20
25
Gracie Creek REE February 2010
-Photos-
___________________________________________________________
M.C. Wright and Associates
Gracie Creek REE 2010
11
Gracie Creek Photo Chronology - Main Stem
0-050
Photos taken from photostation 1208
2005
Photo looking downstream towards Sproat Lake from downstream of debris jam.
2010
Photo looking downstream from below log jam to aggraded area out
0+000
Photos taken from photostation 1651
2005
Photo looking downstream to debris jam before construction.
2010
Photo looking downstream to debris jam.
2010
Photo looking upstream towards debris jam.
Photos from photostation 1651 cont.
2004
Looking upstream from photo point 1651 after the channel was complete
2005
Looking upstream from photo station 1651 before construction
2005
Looking upstream from photo station 1651 after construction
0+100
Photos taken from photostation 1652
2005
Looking upstream from photo station 1652 before construction
2005
Looking upstream from photo station 1652 after construction
2010
Photo looking upstream from left bank.
0+300
Photos taken from photostation 1664
2005
Looking upstream from photo station 1654 before construction.
2008
Looking upstream from photo station 1654.
2005
Looking upstream after construction.
2010
Looking upstream from photo station 1664 (987).
2008
View of the riffle crest at 0+300.
0+350
Photos taken from photostation 1655
2005
Looking upstream from photo point 1655 before construction.
2008
2005
Looking upstream from photo point 1655 after construction.
2010
2008
Photo showing armor at 0+380 covered in sediment from Trib.50.1,
which is being transported downstream and causing channel aggrading.
2010
Photo looking upstream from right bank, looking at outlet of Trib.50.1
Looking downstream from photo station 1655.
Looking downstream from photo station 1655
Photos taken from photostation 1655 cont.
2010
Photo showing excesive erosion behind riprap armour on right bank.
0+450
Photos taken from photostation 1657
2004
Looking downstream from photo point 1657 after restoration was complete.
2010
Looking downstream from photo station 1657
2010
Photo looking upstream from photo station 1657
Photos taken from photostation 1657 cont.
2010
2010
0+500
Photos taken from photostation 1659
2010
Photo taken from photo station 1657 showing severe erosion upstream of riprap
also identified channel widening.
Photo looking downstream showing severe erosion upstream of riprap,
also identified channel widening.
0+600
Photos taken from photostation 1661
0+620
Photos taken from photostation 1662
2010
Photo looking downstream showing extensive scour.
2004
Looking downstream from photo station 1662 after channel restoration was complete.
2010
Photo looking upstream showing severe erosion upstream of riprap,
also identified channel widening
Photos taken from photostation 1193
2010
2010
2010
2010
2010
Photos showing severe erosion on right bank.
0+700
Photos taken from photostation 1664
2004
Looking upstream from photo station 1664 after the restoration was complete.
Photo looking upstream from photo station 1664
Photo looking downstream from photostation 1664.
0+750
Photos taken from photostation 1665
2004
Looking upstream from photo station 1665 after restoration of channel was complete.
2010
Photo looking upstream at groyne.
Gracie Creek Photo Chronology - Trib. 50.1
Looking upstream from 50.1 trib downstream weir at sediment in channel.
Looking upstream from 50.1 trub at second weir.
Looking upstream into small inlet tributary which is contributing fine sediment to
50.1 tributary
Looking downstream in 50.1 tributary
Looking downstream in 50.1 tributary
Looking upstream from mid channel in tributary 50.1 from apporox. 0+200m
Photo taken from 0+260, looking upstream.
Photo taken from 0+260, looking downstream at eroding left bank - photo taken
from vegetated island in middle of the channel.
Looking downstream to fork in 50.1 channel.
Looking downstream in new branch channel.
Looking downstream to fork in 50.1 channel.