Site Evaluations
Haight Creek
Site Information
Site Location:
Coast Range, S Willamette Valley, Siuslaw River Tributary, near Alma
Year Installed:
Pre-1987
Lat/Long:
123°30’1.49”W
43°52’32.70”N
Watershed Area (mi2):3.76
Stream Slope (ft/ft)1: 0.0077
Channel Type:
Pool-riffle
Bankfull Width (ft): 19
Survey Date:
March 8, 2007
1
Water surface slope extending up to 20 channel widths up and downstream of crossing.
Culvert Information
Culvert Type:
Open-bottom arch
Culvert Material:
Annular CMP
Culvert Width:
19
Outlet Type:
Mitered
Culvert Length:
62
Inlet Type:
Mitered
Pipe Slope (structure slope): 0.005
Culvert Bed Slope: 0.001
(First hydraulic control upstream of inlet to first hydraulic control downstream of outlet.)
Culvert width as a percentage of bankfull width: 1.01
Alignment Conditions: Appears to have been aligned to minimize length under road. Inlet is shifted
too far to the left, and is likely creating the erosion observed on left bank upstream of inlet.
Bed Conditions: Bedrock (sandstone) dominates in pipe. Bedrock scoured in places. Some gravel/
cobble forming riffle at downstream portion of pipe. Material possibly remaining in pipe due to Siuslaw
backwater.
Pipe Condition: Light to medium rust. Some structure joints open.
Hydrology
Discharge (cfs) for indicated recurrence interval
25% 2-yr
Qbf2
2-year
5-year
10-year
50-year
100-year
41
150
165
242
295
418
471
Bankfull flow estimated by matching modeled water surface elevations to field-identified bankfull elevations.
2
Haight Creek
A—241
Culvert Scour Assessment
Points represent survey points
Figure 1—Plan view map.
A—242
Haight Creek
Site Evaluations
History
The exact installation date is unknown, but
the culvert was included in the 1987 Western
Federal Lands Highway Division (WFLHD)
“Oregon Culvert Fish Passage Survey;” the field
survey for the WFLHD study was conducted on
December 8, 1987. With respect to fish passage,
Oregon Department of Fish and Wildlife staff
rated the site as a “good” installation. Their
comments consisted of the following “access
to stream good at most flows, except extreme
low summertime. Metal of culvert beginning to
corrode near waterline, but concrete sill shows
no sign of wear. No buildup of gravel or other
material. Soft sandstone bedrock bottom. Bridge
was offset from normal stream channel by 15
feet on upstream end. Bridge should have been
placed more directly inline with streamflow.
Some erosion noted at this point, probably due
to creation of back eddy.” WFLHD staff rated
the condition of the foundation as “fair,” with
negligible outlet scour. The culvert hydraulics
were rated as “compatible” with the natural
stream hydraulics. They note that because the
foundation is located on sandstone, scour at the
foundations may be a problem.
The following are photos from the WFLHD study:
Culvert inlet.
Haight Creek
Typical stream channel.
Site Description
The Haight Creek culvert is a bottomless arch
mitered to conform to the slope of the road fill.
Exposed footings run along the length of the
crossing. Riprap lines both banks upstream of the
culvert. The channel through the culvert is made
up of sandstone bedrock overlain by sand and
small gravels. For the most part, the bed lacks
any bedforms with the exception of a scour pool
towards the downstream end.
The transition from the Haight Creek drainage
into the flood plain of the Siuslaw River is
accompanied by an abrupt flattening out of the
gradient. Due to the location of the crossing
immediately downstream of this transition,
the influence of the Siuslaw on the hydraulics
and geomorphic condition of the culvert are
significant. Suspected backwatering during low
to mid-range floods through and upstream of
the culvert forced the location of the upstream
representative reach to be pushed a significant
way upstream, past a sharp bend in the channel.
The upstream representative reach had riffles
interspersed by glides/pools. High banks
along both sides indicate that the channel may
be somewhat incised through this reach, an
observation supported by the results from the
A—243
Culvert Scour Assessment
hydraulic model. Incision through this reach is
likely a contributor to narrow bankfull widths
measured as equal as or less than the culvert.
The growth of vegetation along the banks and out
over the channel adds roughness to the channel
and also provides shade and cover.
Downstream of the culvert the stream channel is
influenced by the Siuslaw River. Bank height and
channel dimensions do not bear any signature
of Haight Creek. The deposition of fines and
sand along the banks, through the culvert, and
extending upstream to a bar located at a sharp
bend in the channel indicate that the hydraulic
effects of the Siuslaw on the channel are frequent
and extensive. Based on the profile, minor
changes in stage of the Siuslaw (i.e., less than
a foot) would result in water backing up into the
culvert. Without knowledge of the timing of floods
on Haight Creek and the Siuslaw and without
survey data and a stage-discharge relationship
for the Siuslaw, it is hard to know the specific
extent or frequency of backwater.
Survey Summary
Twelve cross sections and a longitudinal
profile were surveyed along Haight Creek in
March 2007 to characterize the culvert and an
upstream representative reach. No downstream
representative reach was established due to
the proximity of the confluence with the Siuslaw
River. Two representative cross sections
were taken through the culvert; one along the
plane-bed section and the other through the
downstream scour pool. One additional cross
section was surveyed upstream to characterize
the inlet as well as the contraction of flow. Another
two cross sections were surveyed downstream
of the culvert to characterize the outlet and the
expansion of flow.
A—244
Representative cross sections in the upstream
representative reach were taken through a riffle
and a glide/pool. Two additional sections were
surveyed to characterize the upstream and
downstream ends of the reach.
Profile Analysis Segment Summary
The profile analysis resulted in a total of nine
profile segments. The culvert consisted of one
profile segment that extended into inlet and
outlet transition areas. The culvert segment was
compared to one representative profile segment
in the upstream channel. The gradients are
63-percent different between these two segments,
but because of their very flat profiles and
similarity in channel type, they are considered
suitable comparisons. The downstream transition
area was compared to one representative profile
segment in the upstream channel. A transition
area comparison was not made for the upstream
transition because the culvert segment extends
through the upstream transition area. Therefore,
the culvert segment also represents conditions
in the upstream transition area that is affected by
the culvert. See figure 2 and table 1.
Scour Conditions
Observed conditions
Footing scour – There is scour upstream of the
inlet on the right bank at the base of the riprap
bank. There is scour at the inlet on the left bank
along the footing. There is approximately 20 lineal
feet of scour (18 inches deep) at the downstream
end of the culvert on the right bank. These areas
of scour are in the sandstone bedrock.
Culvert-bed adjustment – The culvert is primarily
(80 percent) sandstone bedrock. It is unknown
whether streambed material was placed on the
bed during construction.
Haight Creek
Site Evaluations
Profile characteristics – The profile shape is
concave with the maximum concavity focused
upstream of the inlet. The crossing is located
in an area of valley transition where the Haight
Creek valley meets the broad valley of the
Siuslaw River.
Residual depths – Culvert residual depths
are greater than the residual depths in the
corresponding profile segment (G) (figure 21).
Residual depths in the downstream transition
segment (A) are comparable to those in the
corresponding profile segment (I).
Substrate – The culvert is primarily sandstone
bedrock. The alluvial material that is present is
primarily composed of fine material. The bed
material distribution in the culvert is negatively
skewed, indicating more fine particles than
coarse particles. The bed material in the culvert is
heavily influenced by backwater from the Siuslaw
during high flows. The upstream representative
segment has significant portions of bedrock and
sand. Large deposits of sand in the upstream
transition segment are a result of backwater from
the Siuslaw.
Predicted conditions
Cross-section characteristics – The culvert affects
flow geometry at the crossing. The width-related
parameters (top width and wetted perimeter) are
actually greater in the culvert at low flows and
lower at high flows (figures 6 and 8). Values of
maximum hydraulic radius and maximum depth in
the culvert are greater than in the corresponding
profile segment (figures 9 and 14). The box plots
do not adequately represent conditions in the
culvert because the culvert segment extends into
inlet and outlet transition areas. The downstream
transition segment (A) has lower width and
wetted perimeter but similar depth and hydraulic
radius when compared to the corresponding
profile segment (I).
Haight Creek
Shear stress – Shear stress in the culvert is lower
and less variable than in the natural channel
(figure 10). Shear stress has higher values and
a greater range of values in the downstream
transition segment at the Q50 and above.
Excess shear – The excess shear analysis
shows little difference between the culvert and
the channel. Bed mobilization would be affected
by backwater conditions during high flows on the
Siuslaw, which the excess shear analysis does
not consider.
Velocity – Velocity in the culvert is greater and
less variable than the corresponding profile
segment, particularly at flows above the Q10
(figure 11). Velocity in the downstream transition
segment (A) is greater and more variable than the
corresponding profile segment (I) at most flows.
Scour summary
There is scour into the sandstone bedrock
upstream of the inlet, at the inlet on the left bank
and at the downstream end of the culvert on the
right bank. There is scour along the footing within
the culvert but the footing base is not exposed.
The footing depth is unknown. Scour upstream
of the inlet and at the inlet may be related to
constriction of the channel at this location (necks
down to 9 feet at one location) and to the sharp
bend as the channel enters the culvert.
Channel incision is apparent upstream of the
inlet and may be the result of this or a previous
installation.
The culvert affects flow geometry and hydraulics
but shear stress and excess shear do not
indicate significant risk of scour to the culvert
bed. The potential for scour is further reduced by
the common occurrence of backwater from the
Siuslaw River at high flows. The sandstone bed,
however, is easily eroded and continued erosion
may undermine footings over time.
A—245
Culvert Scour Assessment
AOP Conditions
Cross-section complexity – The sum of squared
height differences in the culvert cross sections
are either less than (upstream cross section)
or greater than (downstream cross section) the
values in the representative channel (table 3).
Profile compolexity – Vertical sinuosity in the
culvert and in the downstream transition segment
is similar to that found in corresponding profile
segments (table 4).
Depth distribution – There is less channel margin
habitat in the culvert compared to the channel at
the 25 percent Q2 (table 5).
Habitat units – The culvert is composed of
glide and pool habitat whereas the upstream
representative reach is composed of riffle and
pool habitat (table 6).
Residual depths – Culvert residual depths
are greater than the residual depths in the
corresponding profile segment (G) (figure 21).
Residual depths in the downstream transition
segment (A) are comparable to those in the
corresponding profile segment (I).
Substrate – The culvert is primarily sandstone
bedrock. The alluvial material that is present is
primarily composed of fine material. The bed
material distribution in the culvert is negatively
skewed, indicating more fine particles than
coarse particles. The bed material in the culvert is
heavily influenced by backwater from the Siuslaw
during high flows. The upstream representative
segment has significant portions of bedrock and
sand. Large deposits of sand in the upstream
transition segment are a result of backwater from
the Siuslaw.
A—246
Large woody debris – There was one small piece
of LWD at the inlet (table 8). The representative
channel had low LWD abundance. LWD formed
occasional scour pools in the channel outside the
crossing. There were no features in the culvert
that mimicked the role of wood in the natural
channel.
AOP summary
Although the complexity metrics do not capture
it, site observations indicate that the bedrock
bed of the culvert has much less complexity than
the natural channel upstream of the culvert. The
culvert is considered a poor design with respect
to fish passage, with very little shallow channel
margin habitat available and very little velocity
refuge such as what is provided by substrate
and pools in the natural channel. At low flows,
shallow sheet flow over bedrock may present
passage limitations. There are no streambanks
to concentrate flows for passage or to allow
for passage of terrestrial organisms. At higher
flows, however, backwatered conditions from the
Siuslaw may allow for easy fish passage through
the crossing.
Design Considerations
Inlet scour may be reduced with an installation
that is more inline with the original channel, which
would require a longer culvert. Using a wider
culvert and constructing a stable bed foundation
may allow for material to be retained within
the pipe. Constructing banks using stable bed
elements (i.e., boulders) within the culvert would
protect the footings from being undermined by
scour of the sandstone bedrock. This would also
allow for the passage of terrestrial organisms;
however, passage of terrestrial organisms may
be limited at higher flows when the culvert is
backwatered by the Siuslaw River.
Haight Creek
Haight Creek
Pebble count
(riffle)
498
750
700
A
650
XS 2
XS 3
600
XS 4:
Pebble count
(glide)
C ulvert
B
550
XS 6
I
C u lv e rt S e g m e n t
B
D o w n s tre a m T ra n s itio n
A
XS 7
500
XS 5:
Pebble count
(glide)
R e p re s e n ta tiv e C h a n n e l
S egment
G
Table 1­—Segment comparisons
Figure 2—Haight Creek longitudinal profile.
Relative elevation (ft)
500
502
XS 1:
Relative Elevation (feet)
504
506
508
510
450
400
350
D is ta nc e Along T ha lweg (feet)
13.3%
% D iffe re n c e in
G ra d ie n t
62.6%
XS 8
C
D
124
38
64
30
60
150
E
F
G
H
I
200
S egm ent L ength
(ft)
69
146
76
71
250
XS 9
S egm ent
A
B
C
D
300
E
F
G
0.005
0.012
0.003
0.022
0.009
S egm ent
G ra dient
0.010
0.001
0.025
0.013
100
H
50
I
XS 12
0
Site Evaluations
A—247
n
o
i
t
a
v
e
l
E
)
t
f
(
A—248
0.048 – 0.0492
0.03 – 0.0635
0.0629 – 0.0632
0.0638 – 0.0646
A
B
G
I
SegmentRange of Manning's n values1
1
2
6
2
# of measured XSs
8
6
16
9
# of interpolated XSs
Elevation (ft)
498
500
502
504
506
508
510
512
0
1
5
.
1
4
.
2 2
3
4
100
5
5
.
5
7
200
8
*
5
0
.
8
*
1
.
8
*
5
1
.
8
*
5
2
6
4
.
8
*
3
5
.
8
*
9
5
.
8
400
Main Channel Dis tance (ft)
2
.
8
300
5
7
2
.
8
*
5
7
8
3
.
8
*
5
6
.
8
8
6
.
8
*
6
6
6
4
7
.
8
*
5
9
7
.
8
4
8
.
8
7
8
.
8
*
5
9
.
8
500
*
1
.
9
3
.
9
Stations with decimal values are interpolated cross sections placed along the surveyed profile.
Figure 3—HEC-RAS profile.
1
*
5
6
.
9
0
1
*
6
*
6
5
6
6
1
.
.
0
1
1
1
600
5
.
1
1
7
.
1
1
5
7
.
1
1
Obtained using equation from Jarrett (1984): n = 0.39S0.38R-0.16, where S=stream slope; R=hydraulic radius. Jarrett’s equation only applied
within the following ranges: S = 0.002 to 0.08, R = 0.5 ft to 7 ft. For cross sections outside these ranges, n was computed either from adjacent
sections that fell within the ranges, using the guidance of Arcement and Schneider (1987), or from the HEC-RAS recommendations for culvert
modeling.
Table 2—Summary of segments used for comparisons
2
1
1
.
2
1
700
Ground
W S 41 c fs
W S Qbf
W S Q10
W S Q50
W S Q100
L e ge nd
Culvert Scour Assessment
Haight Creek
Haight Creek
Elevation (ft)
n
o
i
t
a
v
e
l
E
)
t
f
(
n
o
i
t
a
v
e
l
E
)
t
f
(
502
0
10
.07
20
20
40
Station (ft)
30
.0632
RS = 10
Station (ft)
30
40
50
50
.07
.07
60
60
Bank St a
Gr ound
WS 41 c fs
WS Qbf
WS Q10
WS Q50
WS Q100
L e ge nd
Bank St a
Ground
WS 41 c fs
WS Qbf
WS Q10
WS Q50
WS Q100
L e ge nd
n
o
i
t
a
v
e
l
E
)
t
f
(
n
o
i
t
a
v
e
l
E
Elevation (ft)
0
502
20
504
506
508
510
512
514
502
504
506
508
510
512
514
.07
.07
30
10
40
.0625
20
30
Station (ft)
50
RS = 9
Station (ft)
.0629
RS = 11
60
40
70
.07
50
.07
80
60
Bank St a
Gr ound
WS 41 c fs
WS Qbf
WS Q10
WS Q50
WS Q100
L e ge nd
Bank St a
Gr ound
WS 41 c fs
WS Qbf
WS Q10
WS Q50
WS Q100
L e ge nd
Figure 4—Cross-section plots. Only measured cross sections are included. Manning’s n values are included at the top of the cross section. The
stationing (RS) corresponds to the stationing on the HEC-RAS profile. Green arrows define the ineffective flow areas. Black arrows represent
points identified in the field as the bankfull channel boundary. Only those points identified in the field and supported by hydraulic and topographic
analyses are shown below.
Elevation (ft)
504
506
508
10
.0646
Elevation (ft)
510
512
514
504
506
508
510
512
514
516
.07
RS = 12
)
t
f
(
Site Evaluations
A—249
n
o
i
t
a
v
e
l
E
)
t
f
(
Elevation (ft)
n
o
i
t
a
v
e
l
E
)
t
f
(
A—250
498
70
80
.065
40
90
50
Station (ft)
100
.0584
RS = 6
Station (ft)
60
.0635
70
110
80
120
.055
.07
90
130
B a n k S ta
In e ff
L e ve e
G ro u n d
W S 4 1 c fs
W S Qb f
W S Q1 0
W S Q5 0
W S Q1 0 0
L e ge n d
Bank St a
Ground
WS 41 c fs
WS Qbf
WS Q10
WS Q50
WS Q100
L e ge nd
n
o
i
t
a
v
e
l
E
)
t
f
(
Elevation (ft)
498
-20
500
502
504
506
508
510
498
20
500
502
504
506
508
510
-10
30
.07
0
.
0
1
3
40
Station (ft)
10
.03
RS = 5
Station (ft)
50
.063
RS = 7
.
0
1
3
20
60
30
70
.07
40
80
L e ge nd
Bank St a
Ground
WS 41 c fs
WS Qbf
WS Q10
WS Q50
WS Q100
L e ge nd
Bank St a
Ground
WS 41 c fs
WS Qbf
WS Q10
WS Q50
WS Q100
Figure 4—Cross-section plots. Only measured cross sections are included. Manning’s n values are included at the top of the cross section. The
stationing (RS) corresponds to the stationing on the HEC-RAS profile. Green arrows define the ineffective flow areas. Black arrows represent
points identified in the field as the bankfull channel boundary. Only those points identified in the field and supported by hydraulic and topographic
analyses are shown below. (continued)
Elevation (ft)
500
502
504
.07
n
o
i
t
a
v
e
l
E
Elevation (ft)
506
508
510
498
30
500
502
504
506
508
510
RS = 8
)
t
f
(
Culvert Scour Assessment
Haight Creek
n
o
i
t
a
v
e
l
E
)
t
f
(
Elevation (ft)
n
o
i
t
a
v
e
l
E
)
t
f
(
Haight Creek
498
50
60
.05
70
0
Station (ft)
80
.0484
RS = 2
Station (ft)
10
.03
.
0
1
3
.06
90
20
.07
100
30
)
t
f
(
B a n k S ta
In e ff
G ro u n d
W S 4 1 c fs
n
o
i
L e ge n d
t
W S Q1 0 a
0
W S Q5 0v
e
W S Q1 0
l
W S Qb f
E
110
40
Bank St a
Ground
WS 41 c fs
WS Qbf
WS Q10
WS Q50
WS Q100
L e ge nd
Elevation (ft)
498
40
500
502
504
506
508
510
498
70
500
502
504
506
508
510
80
50
.07
.07
.
0
5
5
60
90
70
.
0
5
5
.0483
RS = 1
Station (ft)
.05
100
Station (ft)
.0476
RS = 3
80
.06
110
90
.07
120
.07
W S Qb f
W S Q1 0
W S Q5 0
Bank St a
Ground
WS 41 c fs
WS Qbf
WS Q10
WS Q50
WS Q100
L e ge nd
B a n k S ta
In e ff
G ro u n d
W S 4 1 c fs
130
100
L e ge n d
W S Q1 0 0
Figure 4—Cross-section plots. Only measured cross sections are included. Manning’s n values are included at the top of the cross section. The
stationing (RS) corresponds to the stationing on the HEC-RAS profile. Green arrows define the ineffective flow areas. Black arrows represent
points identified in the field as the bankfull channel boundary. Only those points identified in the field and supported by hydraulic and topographic
analyses are shown below. (continued)
Elevation (ft)
500
502
504
.07
-10
.
0
1
3
n
o
i
t
a
v
e
l
E
Elevation (ft)
506
508
510
498
-20
500
502
504
506
508
510
RS = 4
)
t
f
(
Site Evaluations
A—251
A—252
.
P
.
W
l
a
t
o
T
0
50
100
150
200
250
300
0
A
100
Culvert
B
200
0
0
A
B
100
Culvert
Figure 6—Wetted perimeter.
W.P. total (ft)
20
40
60
80
100
200
Figure 5—Flow area (total) profile plot.
Flow area (sq ft)
)
t
f
(
w
o
l
F
a
e
r
A
q
s
(
)
t
f
C
C
400
400
Main Channel Distance (ft)
300
D
Main Channel Distance (ft)
300
D
E
E
500
500
F
F
G
G
H
600
Flow
600
H
I
I
700
700
W.P. Total 41 cfs
W.P. Total Qbf
W.P. Total Q10
W.P. Total Q50
W.P. Total Q100
Legend
Flow Area 41 cfs
Flow Area Qbf
Flow Area Q10
Flow Area Q50
Flow Area Q100
Legend
Culvert Scour Assessment
Haight Creek
Haight Creek
p
o
T
h
t
d
i
W
0
1
2
3
4
5
0
A
100
0
10
20
Figure 8—Top width.
Top width (ft)
30
40
50
100
200
300
D
400
E
500
500
F
F
G
G
H
Main Channel Distance (ft)
600
Flow
600
Flow
H
I
I
700
700
Top Width Q100
Legend
Hydr Radius 41 cfs
Hydr Radius Qbf
Hydr Radius Q10
Hydr Radius Q50
Hydr Radius Q100
Legend
Top Width 41 cfs
Top Width Qbf
Top Width Q10
C
E
60
Culvert
B
400
Main Channel Distance (ft)
300
D
Top Width Q50
A
200
C
70
80
90
B
Culvert
Figure 7—Hydraulic radius.
Hydraulic radius (ft)
)
t
f
(
r
d
y
H
s
u
i
d
a
R
)
t
f
(
Site Evaluations
A—253
r
a
e
h
S
n
a
h
C
q
s
/
b
l
(
B
200
C
300
D
400
E
E
500
F
F
G
G
600
H
Flow
H
I
I
700
Max Chl Dpth Q100
Legend
0
1
2
3
4
A—254
0.0
0
A
100
Culvert
200
Figure 10—Shear stress (channel) profile.
Shear channel (lb/sq ft)
0.5
1.0
1.5
2.0
2.5
400
Main Channel Distance (ft)
300
D
Main Channel Distance (ft)
500
600
Flow
700
Shear Chan 41 cfs
Shear Chan Qbf
Shear Chan Q10
Shear Chan Q50
Shear Chan Q100
Legend
Max Chl Dpth 41 cfs
Max Chl Dpth Qbf
Max Chl Dpth Q10
100
C
5
0
Culvert
B
Max Chl Dpth Q50
A
6
7
8
Figure 9—Maximum depth.
Maximum channel depth (ft)
)
t
f
x
a
M
l
h
C
h
t
p
D
)
t
f
(
Culvert Scour Assessment
Haight Creek
Haight Creek
l
e
V
l
n
h
C
)
s
/
t
f
(
0
0
200
Figure 11—Velocity (channel) profile plot.
Velocity channel (ft/s)
1
2
3
4
100
300
D
400
E
500
F
G
600
H
I
700
Vel Chnl Q100
Legend
Main Channel Distance (ft)
Vel Chnl 41 cfs
Vel Chnl Qbf
Vel Chnl Q10
C
5
Culvert
B
Vel Chnl Q50
A
6
7
8
Site Evaluations
A—255
A (ds
trans)
B (culv)
25%Q2
B (Culvert)
G
Figure 12—Flow area (total).
0
40
A (DS Trans)
Flow Area (ft2)
G
80
I
I
120
A (ds
trans)
Qbf
B (culv)
G
G
160
I
I
A (ds
trans)
10
B (culv)
50%
of the
values
G
G
B (Culvert)
A (DS Trans)
I
A (ds
trans)
50
B (culv)
Minimum value
25th percentile
G
I
Median (aka 50th percentile)
75th percentile
G
100%
of the
values
I
Maximum value
I
B (Culvert)
A (DS Trans)
A—256
A (ds
trans)
100
B (culv)
G
G
Flow area (sq ft)
I
I
Box Plot Explanation
Culvert Scour Assessment
Haight Creek
B (Culvert)
A (DS Trans)
B (Culvert)
A (DS Trans)
A (ds
trans)
B (culv)
G
25%Q2
A (ds
trans)
B (culv)
G
25%Q2
Figure 14—Hydraulic radius.
0
Hydraulic
Radius (ft)
1
2
3
4
5
Figure 13—Wetted perimeter.
0
I
I
A (ds
trans)
A (ds
trans)
A (DS Trans)
A (DS Trans)
Wetted
10 Perimeter (ft)
Qbf
B (culv)
Qbf
G
G
B (culv)
B (Culvert)
B (Culvert)
20
I
I
A (ds
trans)
A (ds
trans)
A (DS Trans)
A (DS Trans)
30
10
B (culv)
10
B (culv)
B (Culvert)
B (Culvert)
40
G
G
I
I
A (ds
trans)
A (ds
trans)
A (DS Trans)
A (DS Trans)
A (DS Trans)
A (DS Trans)
50
B (culv)
50
B (culv)
G
G
I
I
I
50
B (Culvert)
B (Culvert)
B (Culvert)
B (Culvert)
A (ds
trans)
A (ds
trans)
A (DS Trans)
A (DS Trans)
G
G
I
I
G
G
I
I
G
G
I
I
G
G
Hydraulic radius (ft)
I
B (Culvert)
B (Culvert)
Haight Creek
100
B (culv)
100
B (culv)
G
G
Wetted perimeter (ft)
G
G
I
I
I
I
Site Evaluations
A—257
B (Culvert)
A (ds
trans)
B (culv)
G
25%Q2
Figure 16—Maximum depth.
0
2
Max Depth (ft)
4
6
8
B (Culvert)
Figure 15—Top width.
I
A (ds
trans)
A (DS Trans)
A (DS Trans)
25%Q2
A (ds
trans)
Qbf
B (culv)
Qbf
B (culv)
B (Culvert)
B (Culvert)
B (culv)
G
I
A (ds
trans)
A (ds
trans)
A (DS Trans)
A (DS Trans)
A (ds
trans)
10
B (culv)
10
B (culv)
B (Culvert)
B (Culvert)
I
G
G
G
G
G
I
I
I
I
I
A (ds
trans)
A (ds
trans)
A (DS Trans)
A (DS Trans)
G
50
B (culv)
50
B (culv)
G
G
G
G
0
I
I
I
15Width (ft)
Top
B (Culvert)
B (Culvert)
A (DS Trans)
A (DS Trans)
A (ds
trans)
A (ds
trans)
A (DS Trans)
A (DS Trans)
30
100
B (culv)
100
B (culv)
B (Culvert)
B (Culvert)
G
G
I
I
G
G
I
I
Maximum depth (ft)
I
G
G
G
G
A—258
I
I
I
Top width (ft)
I
45
Culvert Scour Assessment
Haight Creek
B (culv)
B (Culvert)
A (ds
trans)
B (culv)
G
25%Q2
Figure 18—Velocity (channel).
0
2
Velocity (ft/sec)
4
6
8
B (Culvert)
I
Figure 17—Width-to-depth ratio.
25%Q2
A (ds
trans)
A (ds
trans)
A (DS Trans)
A (DS Trans)
A (ds
trans)
Qbf
B (culv)
Qbf
B (culv)
B (Culvert)
B (Culvert)
G
G
G
I
I
I
I
G
A (ds
trans)
A (ds
trans)
A (DS Trans)
A (DS Trans)
0
10
B (culv)
10
B (culv)
B (Culvert)
B (Culvert)
5
G
G
G
G
Width-to-depth Ratio
I
I
I
I
10
A (ds
trans)
A (ds
trans)
A (DS Trans)
A (DS Trans)
15
50
B (culv)
50
B (culv)
B (Culvert)
B (Culvert)
20
G
G
I
I
I
I
25
G
G
A (DS Trans)
A (DS Trans)
A (ds
trans)
A (ds
trans)
A (DS Trans)
A (DS Trans)
30
100
B (culv)
100
B (culv)
G
G
G
G
G
G
B (Culvert)
B (Culvert)
I
I
Velocity (ft/sec)
G
I
I
I
Haight Creek
I
Width-to-depth ratio
I
Site Evaluations
A—259
B (culv)
A (DS Trans)
I
Excess Shear (Applied/tcrit)
100
300
A (DS Trans)
D is c h ar g e (c fs )
200
A (ds
trans)
400
Qbf
B (culv)
G
I
500
10
B (culv)
B (Culvert)
I
C u lve rt (D S p e b b le c o u n t) - g lid e
C u lve rt (U S p e b b le c o u n t) - g lid e
U S C h a n n e l (U S p e b b le c o u n t) - riffle
A (ds
trans)
G
A (ds
trans)
A (DS Trans)
A (DS Trans)
B (Culvert)
Figure 20—Excess shear stress.
Excess shear stress is the channel shear divided by the critical shear for bed entrainment
of the D84 particle size. Values of excess shear greater than 1 indicate bed movement
for the D84 particle size.
0
Excess Shear (Applied / tcrit)
0
0.5
1
1.5
2
2.5
Figure 19—Shear stress (channel).
25%Q2
B (Culvert)
A (ds
trans)
G
G
0
I
0.5
G
1
I
Shear Stress (lbs/ft2)
G
1.5
I
2
50
B (culv)
G
G
2.5
I
I
A—260
A (ds
trans)
100
B (culv)
G
G
Shear stress (lbs/ft2)
I
I
3
Culvert Scour Assessment
Haight Creek
B (Culvert)
A (DS Trans)
B (Culvert)
Site Evaluations
Table 3—Sum of squared height difference
Reach XS LocationUnit type
Culvert
Sum of squared
Within range of
height difference channel conditions?
US
Glide
0.01
No
DS
Glide
0.08
No
US
Riffle
0.05
DS
Pool
0.05
Upstream
Table 4—Vertical sinuosity
Segment
LocationVertical Sinuosity (ft/ft)
A
DS transition
1.000
B
Culvert
1.000
C
US channel
1.000
D
US channel
1.002
E
US channel
1.003
F
US channel
1.000
G
US channel
1.000
I
US channel
1.000
Table 5—Depth distribution
Reach
XS Location
25% Q2
Culvert
Within range of
channel conditions?
US
0
No
DS
0
No
US
1
DS
2
Upstream
Table 6—Habitat unit composition
Percent of surface area
Reach
Pool Glide
Riffle
Step
Culvert
31%
55%
0%
0%
Upstream Channel
36%
0%
64%
0%
Haight Creek
A—261
Culvert Scour Assessment
2.5
Residual Depth (ft)
2.0
1.5
1.0
Residual depth (ft)
0.5
Segment I
Segment H
Segment G
Segment F
Segment E
Segment D
Culvert
Segment B:
Segment
A:
DS Transition
Segment C
Segment B
Culvert
Segment A
DS Transition
0.0
Segment C Segment D Segment E Segment F Segment G Segment H
Segment I
Figure 21—Residual depths.
Table 7—Bed material sorting and skewness
Reach
XSUnit
Sorting
Location Type
Culvert
Within range
Skewness
of channel
conditions?
Within range
of channel
conditions?
US
Glide
2.76
No
-0.05
No
DS
Glide
2.66
No
-0.01
No
US
Riffle
2.11
0.35
DS
Pool
2.63
0.60
Downstream
US
Riffle
2.12
0.24
Upstream
Table 8—Large woody debris
Reach
Pieces/Channel
Width
Culvert
0.3
Upstream
0.8
Terminology:
US = Upstream
DS = Downstream
RR = Reference reach
XS = Cross section
A—262
Haight Creek
Site Evaluations
View upstream through culvert.
View downstream of culvert inlet.
Upstream reference reach.
Downstream view from road. Siuslaw River in background.
Upstream reference reach – first flag on right=
Inside culvert – downstream view.
upstream pebble count (riffle), second flag=
downstream pebble count (glide/pool).
Haight Creek
A—263
Culvert Scour Assessment
Material
Frequency
sand
very fine gravel
fine gravel
fine gravel
medium gravel
medium gravel
coarse gravel
coarse gravel
very coarse gravel
very coarse gravel
small cobble
medium cobble
large cobble
very large cobble
small boulder
small boulder
medium boulder
large boulder
very large boulder
bedrock
S ize R ange (mm)
C ount
Item %
C umulative %
6
2
4
0
9
4
4
6
10
8
18
7
9
5
3
0
0
0
0
5
6%
2%
4%
0%
9%
4%
4%
6%
10%
8%
18%
7%
9%
5%
3%
0%
0%
0%
0%
5%
6%
8%
12%
12%
21%
25%
29%
35%
45%
53%
71%
78%
87%
92%
95%
95%
95%
95%
95%
100%
<2
2-4
4 - 5.7
5.7 - 8
8 - 11.3
11.3 - 16
16 - 22.6
22.6 - 32
32 - 45
45 - 64
64 - 90
90 - 128
128 - 180
180 - 256
256 - 362
362 - 512
512 - 1024
1024 - 2048
2048 - 4096
> 4096
20
100%
18
90%
16
80%
14
70%
12
60%
10
50%
8
Frequency
6
40%
30%
4
20%
2
10%
Cumulative Frequency
Bedrock
2048-4096
512-1024
1024-2048
362-512
256-362
180-256
128-180
64-90
90-128
45-64
32-45
22.6-32
16-22.6
8-11.3
11.3-16
5.7-8
<2
4-5.7
<2
0%
2-4
0
Cumulative Frequency
Cross Section: Upstream representative channel – upstream pebble count
2-4
4 - 5.7
5.7 - 8
> 4096
32 -45
45-64
64- 90
8 - 11.3
90 - 128
11.316
- 16
-22.6
22.6- 32
128180
- 180
256
- 256
362
- 362
- 512
512 - 1024
Particle Size Category (mm)
1024
2048
- 2048
- 4096
Particle Size Category (mm)
S ize C las s
S ize perc ent finer
than (mm)
D5
D16
D50
D84
D95
D100
1
10
50
130
222
360
A—264
Material
P erc ent C ompos ition
Sand
Gravel
Cobble
Boulder
Bedrock
6%
47%
39%
3%
5%
Sorting Coefficient:
2.11
Skewness Coefficient: 0.35
Haight Creek
Site Evaluations
Material
sand
very fine gravel
fine gravel
fine gravel
medium gravel
medium gravel
coarse gravel
coarse gravel
very coarse gravel
very coarse gravel
small cobble
medium cobble
large cobble
very large cobble
small boulder
small boulder
medium boulder
large boulder
very large boulder
bedrock
S ize C las s (mm)
C ount
Item %
C umulative %
16
2
2
4
5
3
2
4
4
9
16
13
8
6
1
0
0
0
0
10
15%
2%
2%
4%
5%
3%
2%
4%
4%
9%
15%
12%
8%
6%
1%
0%
0%
0%
0%
10%
15%
17%
19%
23%
28%
30%
32%
36%
40%
49%
64%
76%
84%
90%
90%
90%
90%
90%
90%
100%
<2
2-4
4 - 5.7
5.7 - 8
8 - 11.3
11.3 - 16
16 - 22.6
22.6 - 32
32 - 45
45 - 64
64 - 90
90 - 128
128 - 180
180 - 256
256 - 362
362 - 512
512 - 1024
1024 - 2048
2048 - 4096
Bedrock
18
100%
16
90%
14
80%
70%
Frequency
12
60%
10
50%
8
Frequency
6
40%
30%
4
20%
2
10%
Bedrock
2048-4096
1024-2048
362-512
512-1024
256-362
180-256
128-180
64-90
90-128
45-64
32-45
22.6-32
11.3-16
16-22.6
5.7-8
8-11.3
2-4
4-5.7
<2
2-4
4 - 5.7 - 8
32 -45
45-64
64- 90
8 - 11.3
90 - 128
Bedrock
11.316- 16
-22.6
22.6- 32
128180
- 180
256
- 256
362
- 362
- 512
Particle Size Category (mm)
512 - 1024
1024
2048
- 2048
- 4096
Particle Size Category (mm)
S ize C las s
S ize perc ent finer
than (mm)
D5
D16
D50
D84
D95
D100
1
2.04
60
124.8
190
340
Haight Creek
Cumulative Frequency
0%
<2
0
Cumulative Frequency
Cross Section: Upstream representative cannel – downstream pebble count
Material
P erc ent C ompos ition
Sand
Gravel
Cobble
Boulder
Bedrock
15%
33%
41%
1%
10%
Sorting Coefficient: 2.63
Skewness Coefficient:0.60
A—265
Culvert Scour Assessment
Cross Section: Culvert – upstream pebble count
Material
sand
very fine gravel
fine gravel
fine gravel
medium gravel
medium gravel
coarse gravel
coarse gravel
very coarse gravel
very coarse gravel
small cobble
medium cobble
large cobble
very large cobble
small boulder
small boulder
medium boulder
large boulder
very large boulder
bedrock
S ize C las s (mm)
C ount
Item %
C umulative %
14
5
4
3
5
1
2
3
5
3
3
3
2
1
1
1
0
0
0
51
13%
5%
4%
3%
5%
1%
2%
3%
5%
3%
3%
3%
2%
1%
1%
1%
0%
0%
0%
48%
13%
18%
21%
24%
29%
30%
32%
35%
39%
42%
45%
48%
50%
50%
51%
52%
52%
52%
52%
100%
<2
2-4
4 - 5.7
5.7 - 8
8 - 11.3
11.3 - 16
16 - 22.6
22.6 - 32
32 - 45
45 - 64
64 - 90
90 - 128
128 - 180
180 - 256
256 - 362
362 - 512
512 - 1024
1024 - 2048
2048 - 4096
Bedrock
100%
60
90%
50
70%
Frequency
40
60%
50%
30
40%
Frequency
20
30%
20%
10
Cumulative Frequency
80%
Cumulative Frequency
10%
Bedrock
2048-4096
1024-2048
362-512
512-1024
256-362
180-256
128-180
64-90
90-128
45-64
32-45
22.6-32
11.3-16
16-22.6
5.7-8
2-4
4 - 5.7 - 8
32 -45
45-64
64- 90
8 - 11.3
90 - 128
Bedrock
11.316- 16
-22.6
22.6- 32
128180
- 180
256
- 256
362
- 362
- 512
512 - 1024
Particle Size Category (mm)
1024
2048
- 2048
- 4096
Particle Size Category (mm)
S ize C las s
S ize perc ent finer
than (mm)
D5
D16
D50
D84
D95
D100
1
1
10
90
185
500
A—266
8-11.3
2-4
<2
4-5.7
0%
<2
0
Material
P erc ent C ompos ition
Sand
Gravel
Cobble
Boulder
Bedrock
13%
29%
8%
2%
48%
Sorting Coefficient:
2.76
Skewness Coefficient:-0.05
Haight Creek
Site Evaluations
Cross Section: Culvert – downstream pebble count
Material
S ize C las s (mm)
sand
very fine gravel
fine gravel
fine gravel
medium gravel
medium gravel
coarse gravel
coarse gravel
very coarse gravel
very coarse gravel
small cobble
medium cobble
large cobble
very large cobble
small boulder
small boulder
medium boulder
large boulder
very large boulder
bedrock
C ount
Item %
C umulative %
23
6
5
10
11
13
5
7
4
2
4
1
8
2
0
2
0
0
0
0
22%
6%
5%
10%
11%
13%
5%
7%
4%
2%
4%
1%
8%
2%
0%
2%
0%
0%
0%
0%
22%
28%
33%
43%
53%
66%
71%
78%
82%
83%
87%
88%
96%
98%
98%
100%
100%
100%
100%
100%
<2
2-4
4 - 5.7
5.7 - 8
8 - 11.3
11.3 - 16
16 - 22.6
22.6 - 32
32 - 45
45 - 64
64 - 90
90 - 128
128 - 180
180 - 256
256 - 362
362 - 512
512 - 1024
1024 - 2048
2048 - 4096
Bedrock
100%
25
80%
20
Frequency
70%
60%
15
50%
10
Frequency
40%
30%
5
20%
Cumulative Frequency
90%
Cumulative Frequency
10%
Bedrock
2048-4096
1024-2048
362-512
512-1024
256-362
180-256
128-180
64-90
90-128
45-64
32-45
22.6-32
16-22.6
11.3-16
5.7-8
2-4
4 - 5.7 - 8
32 -45
45-64
64- 90
8 - 11.3
90 - 128
Bedrock
11.316- 16
-22.6
22.6- 32
128180
- 180
256
- 256
362
- 362
- 512
Particle Size Category (mm)
512 - 1024
1024
2048
- 2048
- 4096
Particle Size Category (mm)
S ize C las s
S ize perc ent finer
than (mm)
D5
D16
D50
D84
D95
D100
1
1
10
69
177
400
Haight Creek
8-11.3
<2
4-5.7
<2
0%
2-4
0
Material
P erc ent C ompos ition
Sand
Gravel
Cobble
Boulder
Bedrock
22%
61%
15%
2%
0%
Sorting Coefficient:
2.66
Skewness Coefficient:-0.01
A—267