FSR_2800_MP_5-3_Dar_AOP_Hydraulics_Memo_combined-1.pdf

Memorandum

Western Federal Lands Highway Division 610 E. Fifth Street

Vancouver, WA 98661-3801

MT. BAKER FISH PASSAGE IMPROVEMENTS

FSR 2800 MP 5.3 AOP HYDRAULICS REPORT

To: Betty Chon, WFLHD Project Manager From: Sven Leon, P.E., WFLHD Hydraulics Engineer Date: February 15, 2018 Project: Darrington ERFO – WA EFRO 2016(1)-20(3)

Background

The Forest Service (FS) is replacing a failed culvert on forest service road (FSR) 2800 at mile post (MP) 5.3, Mt. Baker National Forest, Skagit County, Washington (Fig. 1). The Forest Service will maintain the new structure. Western Federal Lands Highway Division (WFLHD) is designing the replacement structure. Recommendations for the proposed aquatic organism passage (AOP) structure design are presented.

AOP Design Criteria

Forest Service biologists confirmed FSR 2800 MP 5.3 crossing requires an AOP structure (48.351/- 121.624, NAD1983). The crossing is located on an unnamed tributary to the North Fork Stillaguamish River. This unnamed tributary provides rearing habitat for steelhead trout, federally listed Endangered Species Act (ESA) anadromous fish species. Cutthroat trout and Coho salmon may be present.

Constructing passable structures at this location will allow their passage to critical habitat.

Fish passage is required by Washington Administrative Code (WAC) 220-660-190, the Endangered Species Act (ESA), and the Magnuson-Stevens Fishery Conservation and Management Act. The recommended fish passage crossing design is consistent with requirements of the Aquatic Restoration Biological Opinion II (ARBOII).

The proposed AOP structure has been designed per Stream Simulation: An Ecological Approach to Providing Passage for Aquatic Organisms at Road-Stream Crossings (USDA-Forest Service 2008). This method provides a simplified design methodology that is intended to mimic natural upstream and downstream processes within the culvert. Fish passage, sediment transport, and debris conveyance within the culvert are designed to function as they would in the adjacent natural channel. Determination of the high and low fish passage design flows, water velocity, and water depth is not required for this method since the stream hydraulic characteristics within the culvert are intended to mimic the stream conditions upstream and downstream of the crossing. The method utilizes streambed materials that are like the adjacent channel, providing similar channel complexity, flow depth, flow velocities, and resting areas.

The following requirements have been incorporated into the AOP design:

Flood Conveyance: Culvert capacity exceeds the 100-year recurrence flood without roadway overtopping.

Culvert Width: Must accommodate the design channel bankfull width plus additional width for construction of stable bank rocks along both sides of the channel inside the culvert. The minimum culvert

Memo to: Betty Chon, WFLHD Project Manager February 15, 2018 bed width is 1.3 times the bankfull channel width for non-entrenched streams. For entrenched streams (entrenchment ratio < 1.4) the minimum width is bankfull channel width plus room for natural channel banks.

Channel Vertical Clearance: Clearance from bed to ceiling must be at least 5 feet to allow for ease of construction, maintenance, and debris removal.

Channel Slope: Reconstructed streambed within the culvert should approximate the average slope of the adjacent stream from approximately ten channel widths upstream and downstream of the culvert site, and should not deviate by more than 1%.

Embedment: Bottom of the culverts should be buried into the streambed between 30 and 50 percent of the culvert height, and a minimum of 3 feet.

Maximum Length of Road Crossing: Length should be less than 150 feet.

Fill Materials: Fill materials are comprised of material similar in size composition to natural bed materials that form the natural stream channels adjacent to the road crossing. Larger material is added for assisting stream gradient retention and providing resting areas for migrating fish.

Water Depth and Velocity: Water depth and velocity in the culvert must closely resemble those existing in the adjacent stream.

FSR 2800 MP 5.3 AOP Culvert

The stream is a tributary to the North Fork Stillaguamish River. The stream crossed Forest Road 28 through an existing 4-foot diameter culvert which is located approximately 170 feet west from the confluence with the North Fork Stillaguamish River. During 2016 flooding the inlet of the culvert was plugged with debris. The roadway embankment then washed out. The stream is developing a new channel that now flows along the south side of the culvert. Bedrock is exposed on both sides of the roadway washout. Bedrock is also intermittently exposed along the bottom of the channel indicating that sediment supply for this stream is low.

Upstream of the culvert, the channel becomes steeper with more frequent segments of exposed bedrock and 12-inch to 18-inch drops. Medium to large logs laying across and within the channel do not appear to be mobilized by flood flows. The stream is confined by bedrock banks in some locations. In other segments the flow depth becomes shallow as it passes over flat smooth bedrock along the channel bottom.

During low flows, this becomes a barrier to fish. A series of waterfalls cascade over bedrock approximately 170 feet upstream of the culvert. This forms a barrier to fish during all flows (Fig. 2).

Downstream of the culvert, the material washed out from the roadway embankment has been deposited over a wide flat area along the edge of the North Fork Stillaguamish River. ATV users have constructed paths across the stream and down the center of the channel bottom to provide access for their vehicles.

This has created an unnaturally flat and wide channel width. This problem will be alleviated once the roadway is repaired. The North Fork Stillaguamish River appears stable with well-established vegetation along its banks. Some deposition is occurring on the inside of the river bend, forming a small bar. The potential for the river to significantly aggrade or degrade appears low.

Due to the steeper upstream channel conditions and downstream modifications made by ATV users, there was very little area to measure an appropriate bankfull width that could be applied to the proposed crossing design. The stream channel which is forming adjacent to the existing culvert provides some indication of what might be a reasonable bankfull design width. Measurements suggest that the natural bankfull width may range between 12 to 14 feet with a channel slope around 4 and 7 percent. Streambed gradation was measured by digital pebble count using FHWA Hydraulic Toolbox, version 4.2, and processing digital-scaled photographs at two stream locations. Resulting gradation is D100 18 to 20 inches, D85 12 to 16 inches, D50 7 to 9 inches, and D15 4 to 5 inches (Fig. 3).

The existing 48-inch culvert had remained in place for a long period with little or no maintenance problems which indicates that large or moderate woody debris is not being transported by the stream. The material observed at the plugged culvert inlet indicates the stream does carry a moderate amount of small sized woody debris. The exposed bedrock upstream indicates that sediment supply is very limited. If bedrock is encountered near the surface of the proposed stream bottom, the thickness of the streambed material placed inside the proposed structure could be relatively shallow. This would make the material subject to washing-out during large flow events. Without sediment being supplied from upstream, the stream is subject to scouring down to bedrock at the crossing.

Available topographic and stream channel ground surveys are limited to near the road embankment. No channel profile was used in developing design.

Recommendations:

Install new culvert on existing culvert alignment.

Install a 108-foot long, corrugated metal arch culvert with 18-foot span and 9-foot rise (Sheet H.20).

Use aluminum pipe for resisting corrosive conditions.

Place culvert arch on 6-foot high precast or cast-in-place concrete footings (Sheet H.20, H.21, and H.24).

Set inlet footing top elevation at 980.2 feet (project datum).

Set outlet footing top elevation at 974.8 feet (project datum).

Slope footing tops 5 percent.

Adjust footing stem wall height as needed for embedding footings into bedrock minimum 1 foot.

Place 2 to 3 feet conserved streambed material inside the culvert matching the gradation of the natural streambed material upstream.

Slope the channel surface to match upstream and downstream flowlines and gradient (6 percent).

Construct a defined flow channel 10 feet wide at the bottom and 24 inches deep (Sheet H.21).

Construct the flow channel banks from coarser gravel, gobble, and boulder material.

Install 18 boulders, approximately 30 inches in diameter, as shown on Sheet H.22 for inducing channel migration and providing low velocity fish resting areas.

Install cast-in-place concrete collars at culvert inlet and outlet (Sheets H.21 and H.23).

Install Class 3 riprap (FHWA FP-14), minimum 3 feet thick, at the inlet and outlet for controlling road embankment erosion near the headwalls (Sheets H.20 and H.21).

Install Class 1-C nonwoven geotextile (FHWA FP-14) under the riprap.

Shape new channel approximately 30 lineal feet immediately upstream and 50 lineal feet immediately downstream for aligning the culvert channel with the natural channel.

Remove channel debris upstream of inlet and downstream of outlet as needed for establishing unobstructed channel.

Seed and plant any disturbed areas with local native vegetation.

No modification of the road profile is needed for accommodating proposed culvert design.

Construction

Work within the ordinary-high-water limits can only be performed between July 16 and February 28.

Temporary flow deflectors placed for isolating the work area and diverting the stream flow must have a minimum height of 3 feet above the stream bottom and be stable assuming 8 feet per second parallel flow and 2 feet maximum water depth. Use plastic-lined channels or pipes for temporally conveying stream flow through the construction area. Protect the outfalls from erosion. Fish passage downstream through the temporary flow diversions is required. Ensure fish can pass smoothly from the upstream diversion point to the downstream diversion point. Locate diversion points in the main stream channel. Fish passage upstream is not required. Assuming in-stream construction occurs July 16 to October 15, temporary flow diversions must have a minimum flow capacity equal to 30 cubic feet per second (cfs).

Temporary stream diversions in place October 16 through February 28 must have minimum flow capacity equal to the 2-year discharge (69 cfs). Before installing the flow deflectors, remove fish from the work area to the level and methods specified in the environmental permits.

Vehicular traffic will not be maintained through the work site. Full construction area dewatering is expected up to the groundwater level for excavation and installing the foundation, culvert, streambed material, backfill, and riprap. Water pumped from work area must be discharged at an upland area near the site. Access for culvert installation work can be accomplished within the existing road embankment footprint. Temporary access route adjacent to the road embankment is needed for installing flow barriers, removing the channel debris, and completing culvert foundation, inlet, interior, and outlet work.

Constructing the proposed culvert and in-stream work may require heavy track-mounted equipment operating on the stream bed, possibly in water up to 2 feet deep.

The State of Washington and the U.S. Fish and Wildlife Service will restrict the release of turbidity from the work areas into the stream. The agencies require turbidity control and monitoring, and should be contacted for specific requirements and allowable discharge limits.

Stream Impacts

The proposed fish passage culvert is expected to dramatically improve stream flow conveyance, sediment transport, and woody debris transport to a level that is similar for adjacent natural streams. Both channel incision and aggradation is expected upstream, inside, and downstream of the proposed fish passage culvert.

A moderate amount of turbidity and sediment is expected to be released when the flow barriers are removed and stream flow is introduced into the newly constructed culvert. The amount of turbidity and sediment will be reduced by removing the flow barriers gradually introducing the stream flow over an extended two to three-hour time.

Operation and Maintenance

Woody debris will tend to accumulate more frequently at the culvert inlet and inside the culvert barrel.

The FS should increase the frequency of culvert inspection and woody debris removal. Stream degradation is not expected to negatively impact culvert structure or performance. Stream aggradation could reduce the culvert hydraulic capacity. Remove sediment from the upstream channel, inside the culvert, the downstream channel when there is less than 6 feet of clearance between the stream bottom and culvert crown at the inlet. Riprap placed at the culvert inlet and outlet should be inspected annually and after each extreme flood event. Replace or reposition dislodged stone.

Floodplain and Flood-rise Impacts

Flood limits and elevations have not been mapped by the National Flood Insurance Program for the site.

The proposed culverts will improve hydraulic conveyance and is not expected to impact flooding at the site.

Hydrology

The USGS StreamStats (version 4) web-based application was used for delineating the watershed and calculating drainage area (0.89 sq. miles), mean basin elevation (1730 feet), canopy cover (87.8 percent), and mean annual precipitation (87.4 inches). Peak discharges were estimated with StreamStats using USGS regression equations from Magnitude and Frequency of Floods in Washington (USGS WRIR 97- 4277). Watershed is entirely within Region 2 for the USGS regression equations. The watershed is entirely heavily forested (Fig.2). Clear-cut logging has occurred and can occur in the future. No flow diversions or lakes occur. The drainage area is mountainous with moderately incised drainages. Area with slopes greater than 30 percent is 5.86 percent. Elevations range from 974 to 2430 feet (NAD83/WGS84). Peak discharges estimates are presented in Table 1.

Dominant flooding is from snow melt. Larger floods typically occur in April, May, and June. Rain-on-snow flood events occur in October, November, and December. Lowest flows occur in July, August, and September.

Culvert Hydraulics

Water surface profiles and culvert capacities were estimated using the FHWA Culvert Hydraulics Analysis Program, HY-8, version 7.5 (results attached). Floods larger than the 2-year were analyzed assuming culvert slope of 6 percent and Manning’s Roughness coefficient of 0.06. Headwater depths are shown on Table 1.

Flow depths and average channel velocities inside the proposed culverts for up to the 2-year peak discharge were estimated with the FHWA Hydraulic Toolbox, version 4.2, open-channel flow calculator.

The calculations assumed 10 feet channel bottom width, 1:1 sides, and 6 percent channel slope. The Manning’s Roughness coefficient was iterated until a Froude number of 1.0 was achieved for the 2-year discharge. This represents the minimum energy for the stream and the channel inside the culvert and models the turbulent nature of natural steep-gradient, cobble-bedded streams. A Manning’s Roughness coefficient of 0.06 was selected. Average channel flow velocities inside the culverts are presented in Figure 4.

attachments: Table 1 Figures 1, 2, 3, and 4 Photographs 1 to 12 Drawings H.20, H.21, H.22, H.23, and H.24 Peak Discharge Estimates HY-8 Calculations Hydraulic Toolbox Calculations

Drainage

Site Area (mi2) 2 5 10 25 50 100 500

Culvert Peak Q (cfs) 0.89 69 NA 130 164 195 220 NA

Water Elev. at Inlet (ft) 981.0 NA 981.0 982.8 983.0 983.3 NA

Clearance at Inlet (ft) 8.2 NA 8.2 6.4 6.2 5.9 NA

Water Depth at Inlet (ft) 1.1 NA 3.0 4.8 5.0 5.3 NA

Notes:

1. USGS - USGS Regression Equations, “Magnitude and Frequency of Floods in Washington”, WRIR 97-4277, 1998.

NA = Not analyzed.

Table 1. Peak Discharges (ft3/sec) and Water Depths at Inlets

Recurrence Intervals (years)

Image date: 7/28/2016

Project AOP Culvert Site Location

Project Area Location

Map printed from National Geographic TOPO

N

North Fork Stillaguamish River

FIGURE 1

FSR 2800 MP 5.3 AOP CULVERT

SITE LOCATION

MP 5.3

400 feet0

Map printed from Google Earth, Image date 7/28/2016.

MP 5.3

N

DA = 0.89 sq. mi.

FIGURE 2

FSR 2800 MP 5.3 AOP CULVERT

DRAINAGE AREA

0 3000 feet

FIGURE 3

FSR 2800 MP 5.3 AOP CULVERT

STREAMBED GRADATION

FIGURE 4

FSR 2800 MP 5.3 AOP CULVERT

2-YEAR FLOW VELOCITY

Photos

PHOTO 1

PHOTO 2

PHOTO 3

2/14/2018

FSR 2800 MP 5.3

The 48-inch culvert inlet plugged with wood debris and sediment.

Culvert outlet.

Culvert and washed out looking North.

The 48-inch culvert inlet became plugged during the 2016 flooding and the roadway was washed out.

Culvert inlet.

PHOTO 4

PHOTO 5

PHOTO 6

2/14/2018

The North Fork Stillaguamish appears stable with well established vegetation along the banks. Some deposition is occurring on the inside of the bend, forming a small bar. The potential for significant aggradation or degradation appears low.

Inside of culvert looking up to inlet.

Per discussions with FS staff the culvert had functioned for extensive time with little or no maintenance issues.

Downstream of the culvert.

The confluence with the North Fork Stillaguamish River is 120 feet downstream (East) of the culvert. ATV trails have been graded across and along the downstream channel.

Looking north from the confluence with the North Fork Stillaguamish River.

PHOTO 7

PHOTO 8

PHOTO 9

2/14/2018

Channel upstream of the culvert.

Series of waterfalls upstream of culvert.

The channel steepens upstream of the culvert. Bedrock can be seen along the channel bottom and banks. The bedrock confines the channel in some locations.

A series of waterfalls cascade over bedrock appproximately 170 feet upstream of the culvert. The falls are a barrier to fish.

Bedrock along channel bottom.

PHOTO 10

PHOTO 11

PHOTO 12

2/14/2018

FSR 2800 MP 5.3

Looking upstream along the culvert.

The stream is currently flowing along the south side of the culvert. The culvert forms a hardened bank on the right. The stream has started to down-cut and form a bank along the left. This indicates that bankfull widths may be in the range of 12 to 14 feet at this location and slope.

Upstream channel.

Bankfull width measurements upstream of the culvert were not applicable to the culvert design due to the much greater slopes and channel confined by bedrock.

Downstream channel.

Defined banks downstream of the culvert are not present due to construction of ATV trails across and along the stream.

Flow spreads out across the trails before entering the North Fork Stillaguamish River.

0 10 20 30 40 50 60 7060 50 40 30 20 1070

8090100110120130 80 90 100 110 120 130 140 150

160 170

975 975

Flow

N

PIPE INLET OUTLET

FISH SPECIES:

INSTREAM WORK WINDOW: 7/16 - 2/28

ACTIVE CHANNEL WIDTH: 14 feet

LENGTH: 108 feet

INFILL TYPE: SBM

SPAN: 18'-0"

FLOWLINE SLOPE: 0.06 ft/ft

TYPE: Conserved

HYDRAULIC INFORMATION

100 100

OHW : 2.0 feet

HW : 5.3 feetQ : 220 cfs

SCALE IN FEET

0 1010 20 25

BURIAL DEPTH: 2 feet BURIAL DEPTH: 2 feet

PLAN & PROFILE

AOP CULVERT

FSR 2800 MP 5.3RISE: 9'-0"

LOWER BEVEL HEIGHT: 1 foot LOWER BEVEL HEIGHT: 1 foot

BEVEL: 1.5(h):1(v) BEVEL: 1.5(h):1(v)

HEADWALL: Concrete collar/riprap HEADWALL: Concrete collar/riprap

H.20

STATE PROJECT

NUMBER

SHEET

I n t_ ft

D c m y fi le s p w p r o d u c ti o n d F S

R

M P

A O

P

C u lv e r t_

L O

C

M t

B a k e r

E R

F O .d g n

WA FS ERFO 2016(1)-20(3)

A

M

F e b r u a r y

C h e c k e d b y

D e s ig n e d b y

I n t_ ft m y fi le s p w p r o d u c ti o n d F S

R

M P

A O

P

C u lv e r t_

L O

C

M t

B a k e r

E R

F O .d g n

INV N/E/EL: 980.2 INV N/E/EL: 974.8

PIPE SLOPE: 0.05 ft/ft

Q : 69 cfs

WALL THICKNESS: 0.2 in

TYPE: CMP Arch - Aluminum

Grade fill to match conc. collar

Remove existing 48" CMP culvert road edgeExisting

Station 41+67.1

LC

Culvert crown Temporary flow barrier

Concrete collar

6%

LC

Footing top, elev 980.2

Footing top, elev 974.8 field verifyon bedrock, Footing bottom, LC

Concrete collar

Class 3 riprap headwall

Class 3 riprap headwall

Concrete collar

Concrete collar

Footing top guide bank

Class 3 riprap

Bedrock surface

Road

Culvert material

Conserved streambed locate as needed

Temporary flow barrier, locate as needed

Temporary flow barrier, guide bankClass 3 riprap channel edgeActive channel edgeActive

Propsed road grade

Temporary flow barrier

Existing stream bottom

Existing grade contour

100-yr WS depth 5.3'

Culvert wall

Culvert stem wall

Culvert foundation

5'-0" 15'-0"

"8 747'-1

.7

H.21

STATE PROJECT

NUMBER

SHEET

I n t_ ft m y fi le s p w p r o d u c ti o n d F S

R

M P

A O

P

C u lv e r t_

L O

C

M t

B a k e r

E R

F O .d g n

WA FS ERFO 2016(1)-20(3)

P e c e m b e r

C h e c k e d b y

D e s ig n e d b y

ELEVATIONS

AOP CULVERT

FSR 2800 MP 5.3

Existing grade

CULVERT OUTLET

48" CMP culvert

Remove existing

48" CMP culvert

Remove existing

CULVERT INLET

for embedding min. 1 foot into bedrock*

Concrete footing, height as needed

Proposed road grade

Proposed road grade

Existing grade for embedding min. 1 foot into bedrock*

Concrete footing, height as needed

TYPICAL CULVERT CHANNEL

Concrete collar

Class 3 riprap headwall

LC

materialConserved streambed

17'-0"

5'-0" 3'-0"

17'-0"

3'-0" 5'-0"

Culvert stream bottomExisting

Existing bedrock

LC Culvert

100-yr WS depth 5.3'

2-yr WS depth 2.0'

2-yr WS depth 2.0'

100-yr WS depth 5.3' materialConserved streambed

Concrete collar Class 3 riprap headwall stream bottomExisting

Existing bedrock

Culvert wall

Culvert wall

10'-0"

14'-0"

18"

NO SCALE

NO SCALE

SECTION A-A

Flow sediment

Streambed

D2

SECTION B-B

PLAN

LC

F lo w

Culvert wall

Channel flowline

A A

B

B

NOTE:

FOOTNOTE:

Streambed cobble

D

D ty p

D ty p

(typ.)

(typ.)

Streambed sediment

36" min.

3.

2.

1.

or Length on plan sheet

LOCATION

(ft)

D

(ft)

W

(in)

GRADATION

COBBLE

STREAMBED

INFILL INFORMATIONAL QUANTITIES

(cuyd)

COBBLE

STREAMBED

(cuyd)

SEDIMENT

STREAMBED

Culvert outlet

Culvert inlet

14 Class E 18

W

(cuyd)

STONE

BANK

CULVERT INTERIOR TREATMENT

SIMULATED STREAM

Streambed sediment

Streambed cobble

Channel flowline

Pipe arch culvert wall

Box culvert wall

18 30 boulder

Fish passage boulder

Fish passage

(in +/- 4)

BOULDER DIAMETER

FISH PASSAGE

ITEM DESCRIPTION UNIT

each

64703-6000

64704-1000

QUANTITY

MITIGATION QUANTITIES

Fish passage boulder

Streambed material cuyd

Stagger in-channel fish passage boulder within the culvert span.

streambed cobble, and bank stone gradations.

See special contract requirements for streambed sediment, Mix streambed cobbles evenly throughout streambed sediment.

60 150

Material.

Quantities included in Item 64704-1000 Mitigation, Streambed[5]

18-inches or as specified on plan sheet.[4] dimension.

smallest4 3 Embed fish passage boulders within active channel [3] streambed sediment.

Construct well defined banks with bank stone and[2] parabolic shape.

Slope streambed aggregate towards flowline to ensure[1]

[3]Fish passage boulder

[2]Bank stone

[2]Bank stone

[1]

[5] d e p th b u r ia l b u r ia l d e p th

H.22

STATE PROJECT

NUMBER

SHEET

WA FS ERFO 2016(1)-20(3)

D A

T E

P

A T

H

X X

X X

C h e c k e d b y

X X

X e s ig n e d b y

150 18 60

Round pipe culvert wall

(each)

BOULDER

FP

top

Streambed

#4 stirrups

18" O.C. See detail

" Anchor bolt @4

SECTION C-C

as needed

Provide beveled washers

ANCHOR BOLT DETAIL

LC

m in

" Ø galvanized4 bolt design - 4" hook

Acceptable anchor

Culvert crown

3'-0"

B

B

C

C

SECTION A-A

A

A

3' -0

Sp an

3' -0

ISOMETRIC VIEW

SECTION B-B

18" O.C. See detail

" Anchor bolt @4 ty p

C lr

18" O.C. See detail

" Anchor bolt @4

#4 Each face

Pipe

3'-0" each face

#4 @ equal spacing

C lr

Per plans (1.5 min.) 2'-0" min. lap splice

(3 each face, 6 total)

#4 Reinf @ equal spacing

#4 stirrups

REINFORCED CONCRETE HEADWALL

E a c h f a c e

Top of footing

Top of footing

Bottom of footing

Bottom of footing

O .C

Anchor dowels

Anchor dowels

COLLAR DETAILS

REINFORCED CONCRETE

OPEN-BOTTOM ARCH

least 1 foot. Excavation and backfill according to Section 209.

be reduced provided the collar is keyed into the rock at

Where bedrock is encountered, the depth of the collar may install bolts as shown.

Provide slotted hole at bolt locations as necessary in order to

2.

1.

NOTE:

NO SCALE

H.23

STATE PROJECT

NUMBER

SHEET

I n t_ ft m y fi le s p w p r o d u c ti o n d H .2

O

B A

R e in fo r c e d

C o n c r e te

C o ll a r d e ta il s .d g n

WA FS ERFO 2016(1)-20(3)

O c to b e r

C h e c k e d b y

D e s ig n e d b y

15°

V a r ie s

4½"

4¼" 8 31 ref.

ref.

foam gasket Closed cell

SECTION

Shim

Grout

Pipe arch

Span (per plan) stem wall

Concrete as required short & long bolts

Structural-plate bolts, R is e p e r p la n in stem wall

Center pipe arch

Pipe arch wall

3" m in twist bend down & anchor lugs, Base channel elev per plan

Bottom of pipe arch, elev per plan

Bottom of footing, elev per plan

Top of footing, GENERAL NOTES:

foundation

Outside of foundation

Inside of

WATERTIGHT FOUNDATION JOINT SECTION

STRUCTURAL DETAILS

OPEN-BOTTOM PIPE ARCH

NO SCALE

sided box culvert wall

Precast three

" thick material16

Base channel, 15" (min.)

Non-shrink grout rope

" mastic 4

" gap2

(outside joint) on top and sides mastic joint wrap

Grout and 9" wide at channel bottom

Streambed elevation material down, per plan

Place streambed

BASE CHANNEL

TOP OF FOOTING/STEM WALL

DETAIL

DETAIL

H.24

STATE PROJECT

NUMBER

SHEET

I n t_ ft m y fi le s p w p r o d u c ti o n d H .2

T y p ic a l_

S tr u c tu r a l_

D e ta il s .d g n

WA FS ERFO 2016(1)-20(3)

O c to b e r

C h e c k e d b y

D e s ig n e d b y

O Ring if required

" (max.)2 12'-9

" (min.)2 12'-6

1'-5" (max.)

1'-3" (min.)

ty p

Bearing Capacity: 2 tons/sq. ft.

SOIL:

all other locations.

cover for concrete cast against ground, and 2-inch minimum for conforming to ASTM A1064, GRADE 65. Provide 3-inch minimum

(ASTM, A615), deformed, grade 60, or welded wire reinforcing

Furnish reinforcing steel bars conforming to AASHTO M31

REINFORCING STEEL:

f'c=3000 psi.

per Section 6-1, with minimum 28-day compressive strength

-inch. Furnish minor concrete for headwall 4 3exposed edges design compressive strength f'c=4500 psi. Chamfer all

Furnish minor concrete per Section 601 with minimum 28-day

CONCRETE:

conforminG to AASHTO M 167 for the sizes and types specified.

Furnish structures and assembly fasteners for connecting plates

STEEL STRUCTURAL PLATE STRUCTURES:

As specified in design specifications.

LIVE LOAD:

Soil: 125 lb per cubic foot.

Concrete: 150 lb per cubic foot.

DEAD LOAD:

with AASHTO LRFD Bridge Design Specifications, latest edition.

latest edition. Design precast stem walls and footings in accordance

Design structural plate arch in accordance with ASTM A796, DESIGN:

precast sections.

Install tie rods or connector plates per manufacturer between

FP-14 (U.S. Customary). Field verify all dimensions and elevations.

Construction of Roads and Bridges on Federal Highway Projects, Federal Highway Administration Standard Specifications for

Detail is for general information only.

CONSTRUCTION:

DETAIL

12" into bedrock to and embedded a min.

footing to be extended

Cast-in-place or precast

>3 feet - 2 per joint

<3 feet - 1 per joint

Stem wall height, precast tapered holes permitted when

"Ø Hole for 1"Ø joint tie,4 inside face

Stem wall

SUPPLEMENTAL PRECAST CONCRETE STEM WALL TIE

m a x

Flow

Attachments

Peak Discharge Estimates

HY‐8 Calculations

Hydraulic Toolbox Calculations

FLOOD DISCHARGE ESTIMATES

UNGAGED WASHINGTON SITES

Project: File:

Desc: By:

Region: 2 Date:

Exceed Coefficients Equation: Q = a(A)^b(P)^c

Prob. a b c Error Source: Magnitude and Frequency of

0.50 0.090 0.877 1.510 56.00% Floods in Washington, 1998.

0.10 0.129 0.868 1.570 53.00% USGS Report 97-4277

0.04 0.148 0.864 1.590 53.00%

0.02 0.161 0.862 1.610 53.00% Culvert Type HW/D K M a

0.01 0.174 0.861 1.620 54.00% CMP Projecting 0.8 0.5 0.667 2.023

Mean Estimated Discharge (Q) Min.

Drain. Annual Exceedance Probability 0.01 Culvert

Station Area Precip 0.50 0.10 0.04 0.02 0.01 Design Dia

(sq mi) (in) (cfs) (cfs) (cfs) (cfs) (cfs) (cfs) (ft)

3020 170

Minimum 0.08 23

0.250 105 30 58 73 87 99 99 5.2

FSR 2660 MP 4.1 8.750 129 928 1,745 2,188 2,611 2,956 2,956 20.3

0.140 130 25 49 62 75 85 85 4.9

0.82 96.7 75 142 179 213 241 241 7.5

0.89 87.4 69 130 164 195 220 220 7.2

1.28 91.8 103 193 242 288 326 326 8.4

FSR 4052 MP 1.9 0.17 129 29 57 73 87 99 99 5.2

FSR 4052 MP 2.55

0.04 121 7 15 19 23 26 26 3.0

FSR 4065 MP 1.15 0.05 160 14 28 36 43 49 49 3.9

0.49 106 55 105 133 159 180 180 6.6

FSR 2083 MP 0.1 - Site 2 0.04 105 6 12 15 18 20 20 2.8

FSR 2083 MP 0.1 - Site 1 0.08 105 11 21 27 33 37 37 3.5

General 0.05 130 10 20 26 31 35 31 3.3

0.10 130 19 36 46 56 64 56 4.2

0.40 130 63 121 154 185 210 185 6.7

0.50 130 76 147 187 224 255 224 7.2

0.70 130 102 197 250 300 340 300 8.1

Mt Baker Snoqualmie ERFO - Darrington Dist.

Major Drainage Peak Flow C.Sourek

FSR 2081 MP 1.3

reg-spec2014

3/31/2017

FSR 2081 MP 2.25

Maximum

FSR 28 MP 11.4

FSR 28 MP 5.3 - AOP

FSR 4052 MP 3.7

FSR 27 MP 6.9

FSR 28 MP 10.3(4?)

2/13/2018 StreamStats https://streamstats.usgs.gov/ss/ 1/2

StreamStats Report

FSR 2800 MP 5.3

Basin Characteristics

Parameter Code Parameter Descript ion Value Unit

BSLDEM30M Mean basin slope computed from 30 m DEM 20.2 percent

CANOPY_PCT Percentage of drainage area covered by canopy as described in OK SIR 2009_5267

87.8 percent

DRNAREA Area that drains to a point on a stream 0.86 square miles

ELEV Mean Basin Elevat ion 1730 feet

ELEVMAX Maximum basin elevat ion 2430 feet

MINBELEV Minimum basin elevat ion 978 feet

NFSL30 Nor th-Facing Slopes Greater Than 30 Percent 0

PRECIP Mean Annual Precipitat ion 87.4 inches

RELIEF Maximum - minimum elevat ion 1450 feet

Region ID: WA Workspace ID: WA20180213230321018000 Clicked Point (Latitude, Longitude): 48.35221, -121.62166 Time: 2018-02-13 15:03:36 -0800

FSR 2800 MP 5.3 HY-8 Culvert Analysis Report

Table 1 - Culvert Summary Table: 18 x 9 CMP arch

* Full Flow Headwater elevation is below inlet invert.

Straight Culvert

Inlet Elevation (invert): 978.00 ft, Outlet Elevation (invert): 972.00 ft

Culvert Length: 108.17 ft, Culvert Slope: 0.0556

Site Data - 18 x 9 CMP arch

Site Data Option: Culvert Invert Data

Inlet Station: 0.00 ft

Inlet Elevation: 978.00 ft

Outlet Station: 108.00 ft

Outlet Elevation: 972.00 ft

Number of Barrels: 1

Culvert Data Summary - 18 x 9 CMP arch

Barrel Shape: Arch, Open Bottom

Barrel Span: 18.00 ft

Barrel Rise: 8.92 ft

Barrel Material: Corrugated Steel

Embedment: 0.00 in

Barrel Manning's n: 0.0350 (top and sides)

Manning's n: 0.0600 (bottom)

Culvert Type: Straight

Inlet Configuration: Mitered to Conform to Slope

Inlet Depression: None

Total Discharge

(cfs) Culvert

Discharge (cfs)

Headwater Elevation

(ft) Inlet

Control Depth (ft)

Outlet Control

Depth (ft)

Flow Type

Normal Depth (ft)

Critical Depth (ft)

Outlet Depth (ft)

Tailwater Depth (ft)

Outlet Velocity

(ft/s) Tailwater Velocity

(ft/s)

69.00 69.00 980.97 2.971 1.437 3-M1t 0.771 0.764 0.818 0.818 4.733 5.014

84.10 84.10 981.38 3.384 0.0* 1-S2n 0.874 0.875 0.874 0.922 5.268 5.392

99.20 99.20 981.78 3.776 0.0* 1-S2n 0.968 0.979 0.968 1.018 5.617 5.728

114.30 114.30 982.17 4.171 0.0* 1-S2n 1.057 1.073 1.057 1.108 5.936 6.029

129.40 129.40 980.85 2.850 0.0* 1-S2n 1.145 1.168 1.145 1.194 6.207 6.304

144.50 144.50 981.14 3.142 0.0* 1-S2n 1.224 1.260 1.224 1.276 6.492 6.558

159.60 159.60 982.74 4.741 0.0* 1-S2n 1.303 1.349 1.303 1.354 6.742 6.793

174.70 174.70 982.87 4.869 0.0* 1-S2n 1.381 1.430 1.381 1.429 6.968 7.013

189.80 189.80 983.00 4.998 0.0* 1-S2n 1.454 1.514 1.454 1.502 7.202 7.220

195.00 195.00 983.04 5.043 0.0* 1-S2n 1.479 1.538 1.479 1.527 7.277 7.288

220.00 220.00 983.26 5.256 0.0* 1-S2n 1.599 1.673 1.599 1.641 7.606 7.601

Table 2 - Downstream Channel Rating Curve (Crossing: FSR 2800 MP 5.3)

Tailwater Channel Data - FSR 2800 MP 5.3

Tailwater Channel Option: Trapezoidal Channel

Bottom Width: 16.00 ft

Side Slope (H:V): 1.00 (_:1)

Channel Slope: 0.0600

Channel Manning's n: 0.0600

Channel Invert Elevation: 972.00 ft

Roadway Data for Crossing: FSR 2800 MP 5.3

Roadway Profile Shape: Constant Roadway Elevation

Crest Length: 200.00 ft

Crest Elevation: 996.00 ft

Roadway Surface: Gravel

Roadway Top Width: 16.00 ft

Flow (cfs) Water Surface Elev (ft) Depth (ft) Velocity (ft/s) Shear (psf) Froude Number

69.00 972.82 0.82 5.01 3.06 1.00

84.10 972.92 0.92 5.39 3.45 1.02

99.20 973.02 1.02 5.73 3.81 1.03

114.30 973.11 1.11 6.03 4.15 1.04

129.40 973.19 1.19 6.30 4.47 1.05

144.50 973.28 1.28 6.56 4.78 1.06

159.60 973.35 1.35 6.79 5.07 1.07

174.70 973.43 1.43 7.01 5.35 1.08

189.80 973.50 1.50 7.22 5.62 1.08

195.00 973.53 1.53 7.29 5.72 1.08

220.00 973.64 1.64 7.60 6.14 1.09

Hydraulic Analysis Report

Channel Analysis: Channel Analysis - FSR 2800 MP5.3 - Channel

Input Parameters

Channel Type: Trapezoidal

Side Slope 1 (Z1): 1.0000 ft/ft

Side Slope 2 (Z2): 1.0000 ft/ft

Channel Width: 10.0000 ft

Longitudinal Slope: 0.0600 ft/ft

Manning's n: 0.0600

Flow: 69.0000 cfs

Result Parameters

Depth: 1.0850 ft

Area of Flow: 12.0271 ft^2

Wetted Perimeter: 13.0688 ft

Hydraulic Radius: 0.9203 ft

Average Velocity: 5.7370 ft/s

Top Width: 12.1700 ft

Froude Number: 1.0170

Critical Depth: 1.0970 ft

Critical Velocity: 5.6683 ft/s

Critical Slope: 0.0578 ft/ft

Critical Top Width: 12.19 ft

Calculated Max Shear Stress: 4.0622 lb/ft^2

Calculated Avg Shear Stress: 3.4456 lb/ft^2