AK Jean AOP Report Final.pdf

Memorandum

Western Federal Lands Highway Division 610 E. Fifth Street

Vancouver, WA 98661-3801

SKILAK LAKE ROAD / UPPER SKILAK LAKE ROAD

JEAN CREEK AOP HYDRAULICS REPORT

To: Stacy Bluhm, WFLHD Project Manager

From: James Neighorn, P.E. and Vernon Bevan, WFLHD Hydraulics Engineer

Date: June 20, 2023

Project: Skilak Lake Road – AK FWS Kenai 1192(1)

Background

The Kenai National Wildlife Refuge (NWR) is proposing Aquatic Organism Passage improvements to culverts within the Kenai National Wildlife Refuge (KNWR) located on Skilak Lake Road and Upper

Skilak Lake Road. The purpose of the culvert improvements is to restore aquatic organism passage, protect visitor safety, preserve the KNWR roadway infrastructure, and ensure roadway drainage structures are of the latest design standards. As part of the project the NWR is replacing a culvert that carries Jean Creek under Skilak Lake Road as it flows towards the Kenai River. The Kenai NWR 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

The proposed AOP structure has been designed following the requirements Culvert Design Guidelines for

Ecological Function (U.S. Fish and Wildlife 2021) and per Stream Simulation: An Ecological Approach to

Providing Passage for Aquatic Organisms at Road-Stream Crossings (USDA-Forest Service 2008). These documents provide simplified design methodologies intended to mimic natural stream processes within the culvert. Sediment transport, debris conveyance and streambed morphology within the culvert should replicate these processes as they occur in the natural channel upstream and downstream of the culvert.

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 replicate the stream conditions upstream and downstream of the crossing. AOP culvert design utilizes streambed materials and sizes which occur in the natural channel, providing similar channel complexity, flow depth, flow velocities, and resting areas.

USFW Alaska Fish Passage Program (USFW/AFPP) Guidelines

The AOP design for the Jean Creek outfall crossing is consistent with the 2021 U.S. Fish and Wildlife

(USFW) Service design guidelines. The 2021 document generally follows the U.S. Forest Service stream simulation approach with certain modifications. The basis for AOP design is the geomorphic analog method. The underlying philosophy of the geomorphic analog method is similar to the stream simulation approach. However, many of the design criteria are based on the 100-year flood event as opposed to a specifically selected design flood. The following USFW/AFPP requirements have been incorporated into the AOP design:

Flood and Debris Conveyance: Culvert capacity is designed to accommodate the 100-year recurrence flood without interfering with the functioning of the floodplain while providing adequate clearance above the flood stage for expected debris.

Memo to: Stacy Bluhm, WFLHD Project Manager

June 2023

Crossing Location: Crossing structure is placed within the pre-development natural channel alignment wherever possible.

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. All culverts will meet design requirements for a 6-foot minimum diameter.

Channel Vertical Clearance: Clearance from bed to ceiling must be at least 4-feet to allow for ease of construction, maintenance, and debris removal. Where possible, clearance will be 5-feet or greater.

Channel Slope: Reconstructed streambed within the culvert approximates the average slope of the stream reference reach. The slope should not deviate by more than 25% from the natural stream slope of the reference reach.

Embedment: Bottoms of round culverts should be buried below the streambed thalweg a minimum of

40% of the pipe diameter. Box or pipe arch culverts should be buried a minimum of 20% of the culvert’s rise.

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

Fill Materials: Fill materials are generally comprised of sediment similar in size composition to natural bed materials that form the natural stream channel above and below the road crossing. Larger material is added to assist grade retention and provide resting areas for migrating fish. A dense, well-graded mixture is specified, with washing in of fines between constructed lifts, to encourage the stream to flow on the surface.

Fill/substrate material for culverts without an adequate sediment supply, such as those situated below a lake or wetland, should be designed to resist the predicted critical shear forces of the 100-year flood.

Water Depth and Velocity: Bankfull water depths and velocities in the culvert must closely resemble those existing reference reach as specified in the 2021 USFW Service guidance document.

Jean Creek AOP Culvert

United States Fish and Wildlife Service (USFWS) has determined that the Jean Creek crossing of Skilak

Lake Road requires an AOP structure (60.483648°, -150.116302°). Federal Lands Highway Division conducted field reconnaissance of the crossing in 2020 and 2021. This reconnaissance data and fish passage assessment data from a FWS 2018 field survey were used to assess crossing and stream conditions.

The crossing is located on Jean Creek, roughly 2.3-miles downstream of Jean Lake and approximately 700-feet upstream from its confluence with the Kenai River (Figure 1). Jean Creek crosses Skilak Lake Road through one 72-inch diameter CMP with another 60-inch diameter CMP providing for flood relief overflow.

Above Skilak Lake Road, Jean Creek is a single thread, meandering channel which flows out of Jean Lake in a south easterly direction. Along this course, it is bordered by the Sterling Highway on the east.

Approximately 800 feet above Skilak Lake Road, the stream is part of a larger wetland complex with observed beaver activity. The backwater created by the roadway has resulted in a large flat wetland floodplain that spans a width of 200 to 300 feet. Excluding beaver activity, little to no larger woody debris transport was observed in this upstream reach. Bankfull channel widths in this upstream section are approximately 7 to 10 feet, with wider channel widths of 13 to 14 feet were influenced by beaver activity or the existing culverts (Photos 3 and 4). Bankfull depths range from 2.5 to 3.3 feet. North of the road the stream is slow moving with a channel slope of approximately 0.4% or less.

Downstream of the crossing, the slope of the terrain steepens to approximately 0.9% slope and the stream transitions to a riffle-pool bedform (Photo 5). Bankfull widths downstream of the culvert are approximately 9 to 10 feet with depth of approximately 2.5 feet (Photos 6 and 7). The channel appears stable with well vegetated banks which supply woody debris to the stream and are accessible for high discharges. As the stream approaches the confluence with the Kenai River, the valley flattens, and channel width expands.

Channel substrate below the culverts consists of cobble and gravel mixed with fines. A streambed pebble counts were performed at two riffles downstream of the crossing. The data was processed using FHWA Hydraulic Toolbox, version 4.2, to compute the resulting gradation: D100 25-inches, D85 3.8-inches, D50 1.72-inches, D15 0.13-inches, and D5 0.08-inches (Figure 3).

The existing crossing is currently served by one 72-inch diameter CMP and another 60-inch diameter CMP (Photos 1 and 2). The 72-inch culvert is situated within the main channel and is active during low and high flows (Photo 1). The other flood relief culvert is elevated and activated during higher flows. This culvert has a sag in the middle and is disconnected from the channel at the outlet (Photo 2 and 9). The active channel culvert has approximately 1.5 feet of cover while the flood relief culvert has little to no cover. The active culvert was free of woody debris (Photos 1 and 8). A minimal amount of small sized woody vegetation was observed in the overflow culvert inlet (Photo 9). The existing culverts are situated perpendicular to the roadway and the active channel culvert is well aligned with the stream thalweg. No scour was observed at the culvert outfall.

Recommendations:

The existing 72-inch culvert and 60-inch overflow pipe are in poor conditions and do not meet USFWS standards for fish-bearing stream crossings and inhibit aquatic organism passage. The flood relief culvert will be replaced with a new 72-inch diameter CMP that matches the existing culvert alignment and slope.

The 72-inch main channel culvert will be replaced per the following:

Install an 82-foot long, structural plate pipe with a 13-foot span and a 13-foot rise.

Place the culvert at a 0.50% slope to simulate the channel slopes upstream of the crossing by setting the inverts at elevation 272.12-feet upstream and at elevation 271.71-feet downstream (project datum).

Embed the culvert 5.5 feet and backfill the culvert interior with streambed material conserved during excavation of the culvert. If the conserved streambed material quantity is insufficient for backfilling the culvert, use material similar to the natural streambed material. Streambed material will be augmented with Class D gradation cobbles specified in the attached Special Contract Requirements (SCR) and Gradation Stability Calculations to provide a dynamically stable substrate.

Allow clearance for debris passage and maintenance access by providing 7.5 feet of clearance from the crown of the culvert and the installed bed material.

Construct a channel with a bankfull width of 10 feet and bankfull depth of 3 feet including a low flow channel and streambanks inside the culvert to provide resting opportunities for fish.

Install 3 rock weirs spaced at 40-foot intervals to help maintain banks and channel shape.

Install 3 round boulders, approximately 36-inches in diameter, for inducing channel migration and providing low velocity fish resting areas.

Install concrete collars to mitigate the influence of frost heaving at pipe ends.

Install Class 3 riprap (FHWA FP-14), minimum 3 feet thick, at the inlet and outlet for controlling erosion near the culvert.

• Replace the 60-inch overflow pipe with a 72-inch overflow pipe to reduce velocities in the main culvert during higher flows.

Construction

The Alaska Department of Fish and Wildlife instream work period is May 15 to July 15. Temporary flow deflectors placed for isolating the work area and diverting the stream flow must have a minimum height of

4-feet above the stream bottom and be stable assuming 6.5-feet per second parallel flow. Use plastic-lined channels or pipes for temporarily conveying stream flow through the construction area. Protect the outfalls from erosion. Ensure fish can pass smoothly through the diversion. Temporary stream diversions in place must provide an equivalent capacity to a 5-foot diameter pipe or demonstrate a minimum flow capacity equal to the 2-year discharge (195-cfs). Before installing the flow deflectors, remove fish from the work area to the level and methods meeting the 2009 ADF&G and FHWA Fish Habitat MOU requirements.

Full construction area dewatering is expected up to the groundwater level for excavation and installing the culvert, streambed material, backfill, and riprap. Water pumped from work area must be discharged at an upland treatment area near the site.

Temporary access routes adjacent to the road embankment are needed for installing flow barriers and completing culvert inlet, interior, and outlet work.

Stream Impacts

The proposed fish passage culvert is expected to dramatically improve stream flow conveyance, sediment transport, and woody debris transport to a level comparable to reaches upstream and downstream of the 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 and introducing the stream flow over an extended two to three-hour time.

Operation and Maintenance

Scour or aggradation of the streambed is expected to occur to some extent, as would be expected for the natural stream. Monitoring at regular intervals, and ideally during flood events, will be especially important during the first few years to ensure that excessive debris accumulation, scour, or aggradation does not impair passage through the culvert. Increase the frequency of culvert inspections and debris removal for the first three years. Fish boulders placed within the culvert and stream channel should be inspected annually and after each extreme flood event to ensure effective backwater and bed retention. Replace or reposition dislodged rock or boulders. Additional rock may need to be installed to correct erosion or channel degradation. 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 negatively impact flooding at the site.

Hydrology

The USGS StreamStats (version 4) web-based application was used for delineating the watershed and calculating the drainage area (10.4 sq. miles) and mean annual precipitation (27-inches). Since delineations made by StreamStats can include inaccuracies for smaller watersheds and flat areas, the delineated watershed was verified by comparing it to both USGS TOPO maps and Digital Terrain Maps produced by the Alaska Division of Geological and Geophysical Surveys. No significant deviations that would impact flow estimates were found.

Peak discharges were estimated with StreamStats using USGS regression equations from Magnitude and

Frequency at Gaged and Ungaged Sites on Streams in Alaska and Conterminous Basins in Canada (USGS

WRIR 2016-5024). The watershed is mostly comprised of forested lands as well as several lakes and ponds including Jean Lake and Upper Jean Lake (Figure 2). These lakes may influence the amount of runoff generated by the basin in two distinct manners. They have the potential to increase runoff due their large impervious surface area. However, lakes may also attenuate surface water flow withing the basin.

Hydraulic modeling of the channel and the existing culverts indicate that the flows derived from the USGS regression equations are likely reasonable estimates of the basin’s hydrology. A summary of peak discharges and their corresponding water depths at the culvert inlet are presented in Table 1.

Dominant flooding is from snow melt. Larger floods typically occur in April and May. Rain-on-snow flood events can occur in October through December. Lower flows typically occur from January to February and

July through September.

Culvert Hydraulics

Hydraulic performance of the culverts was evaluated using the FHWA Culvert Hydraulics Analysis

Program, HY-8, version 7.7. Topographic field survey was used to develop the hydraulic model slopes and elevations. Floods larger than the 2-year were analyzed assuming culvert slope of 0.50 percent and

Manning’s Roughness coefficient of 0.032 for the channel bottom and 0.024 for the culvert sides and top.

The computed outlet tailwater depth of 3.0 for the 2-year discharge was compared with the bankfull channel design depth of 2.9 feet and found to be within the measured range of 2.5 to 3.3 feet in the natural channel.

Hydraulic results are included in the attachments with headwater depths and ratios shown in Table 2.

Attachments: Table 1 - Peak Discharge Estimates

Table 2 – Headwater Depths and Ratios

Figures 1, 2, and 3

Photographs

HY-8 Calculations

USGS StreamStats Report

Drawings

Special Contract Requirements and Gradation Stability Calculations

Tables

Table 1. Peak Discharges Estimates Peak Annual Floods Discharge (ft3/2)

2-Year 195 5-Year 325

10-Year 426 25-Year 563 50-Year 670

100-Year 785 200-Year 903 500-Year 1070

Table 2. Peak Discharges and Water Depths Peak Annual

Floods Discharge (ft3/2) Headwater Depth (HW)

(ft)

HW/D

(D=7.5 ft) 2-Year 195 3.14 0.42

50-Year 670 6.13 0.82 100-Year 785 6.79 0.91

D = Distance between culvert crown and streambed

Image date: 4/17/2011

Project AOP Culvert Site Location

Project Area Location

USGS Topographic Maps on Google Earth

N

FIGURE 1

JEAN CREEK

AOP CULVERT

SITE LOCATION

2500 feet0

Map printed from Google Earth, Image date 04/17/2011.

N

DA = 10.3 sq. mi.

FIGURE 2

JEAN CREEK

AOP CULVERT

DRAINAGE AREA

0 2500 feet

FIGURE 3

JEAN CREEK

AOP CULVERT

STREAMBED GRADATION

Photos

PHOTO 1

7/2021

PHOTO 2

7/2021

PHOTO 3

7/2021

Jean Creek AOP

View of channel above culvert looking upstream.Wetland complex is visible on the right. Bankfull channel widths are approximately 13 to 14 feet within the upstream backwater influence of the existing culvert and beaver activity.

Bankfull channel width further upstream in unimpeded sections are 9 to 10 feet.

Upstream view of 60" culvert outlet.

Visible sag in middle of the culvert

Channel upstream of culvert.

Main channel culvert inlet.

View looking downstream at culvert inlet.

72" culvert has approximately 1.5 feet of cover.

Overflow culvert outlet.

PHOTO 4

7/2021

PHOTO 5

7/2021

PHOTO 6

7/2021

Jean Creek AOP

Looking upstream towards culvert outlet.

Example of woody debris within natural channel. Well vegetated adjacent bankfull benches.

Channel upstream of culvert.

View of channel above culvert looking upstream. Wetland complex is visible on the right. Evidence of beaver activity in channel.

Channel downstream of culvert.

Looking upstream towards culvert outlet.

Riffle-pool is dominant bed form downstream of culvert.

Channel downstream of culvert.

PHOTO 7

7/2021

PHOTO 8

7/2021

PHOTO 9

7/2021

Jean Creek AOP

Inside of overflow culvert outlet.

Example of woody debris within natural channel.

Minimal amount of woody debris in overlfow culvert. Sag in middle of culvert.

Top of overflow culvert outlet.

Minimal amount of cover on 60"overflow culvert.

Channel below culvert looking downstream.

HY-8 Culvert Analysis Report – Proposed AOP Crossing Discharge Data Discharge Selection Method: Specify Minimum, Design, and Maximum Flow

Minimum Flow: 195.00 cfs

Design Flow: 670.00 cfs

Maximum Flow: 785.00 cfs

Table 1 - Summary of Culvert Flows at Crossing: Jean Creek Headwater Elevation (ft)

Total Discharge (cfs)

Jean Creek

AOP

Discharge (cfs)

Floodplain Overflow Discharge (cfs)

Roadway Discharge (cfs)

Iterations

280.76 195.00 146.50 48.71 0.00 10

281.17 254.00 188.93 65.07 0.00 4

281.56 313.00 232.44 80.57 0.00 4

281.95 372.00 275.73 96.38 0.00 3

282.32 431.00 317.87 113.15 0.00 3

282.69 490.00 359.09 130.91 0.00 3

283.04 549.00 399.54 149.47 0.00 3

283.39 608.00 439.54 168.55 0.00 3

283.75 670.00 481.03 188.97 0.00 3

284.07 726.00 518.63 207.44 0.00 2

284.41 785.00 558.30 226.70 0.00 3

288.00 1328.67 943.43 385.24 0.00 Overtopping

Rating Curve Plot for Crossing: Jean Creek

Culvert Data: Jean Creek AOP

Table 1 - Culvert Summary Table: Jean Creek AOP 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)

195.00 cfs 146.50 cfs 280.76 2.70 3.139 3- M1t

2.32 1.59 3.02 3.02 3.79 5.10

254.00 cfs 188.93 cfs 281.17 3.14 3.550 3- M1t

2.76 1.88 3.22 3.22 4.59 4.31

313.00 cfs 232.44 cfs 281.56 3.58 3.945 3- M1t

3.18 2.15 3.38 3.38 5.40 4.18

372.00 cfs 275.73 cfs 281.95 4.01 4.331 3- M2t

3.59 2.41 3.51 3.51 6.18 4.19

431.00 cfs 317.87 cfs 282.32 4.42 4.703 3- M2t

3.99 2.64 3.63 3.63 6.90 4.26

490.00 cfs 359.09 cfs 282.69 4.82 5.066 3- M2t

4.39 2.87 3.74 3.74 7.59 4.35

549.00 cfs 399.54 cfs 283.04 5.20 5.419 3- M2t

4.79 3.08 3.84 3.84 8.23 4.44

608.00 cfs 439.54 cfs 283.39 5.57 5.766 3- M2t

5.22 3.28 3.94 3.94 8.86 4.54

670.00 cfs 481.03 cfs 283.75 5.96 6.126 3- M2t

5.72 3.47 4.03 4.03 9.48 4.65

726.00 cfs 518.63 cfs 284.07 6.31 6.451 3- M2t

6.29 3.65 4.11 4.11 10.04 4.75

785.00 cfs 558.30 cfs 284.41 6.68 6.793 3- M2t

7.50 3.82 4.20 4.20 10.62 4.84

Culvert Barrel Data Culvert Barrel Type Straight Culvert

Inlet Elevation (invert): 277.62 ft, Outlet Elevation (invert): 277.21 ft

Culvert Length: 82.00 ft, Culvert Slope: 0.0050

Culvert Performance Curve Plot: Jean Creek AOP

Water Surface Profile Plot for Culvert: Jean Creek AOP

Site Data - Jean Creek AOP Site Data Option: Culvert Invert Data

Inlet Station: 0.00 ft

Inlet Elevation: 272.12 ft

Outlet Station: 82.00 ft

Outlet Elevation: 271.71 ft

Number of Barrels: 1

Culvert Data Summary - Jean Creek AOP Barrel Shape: Circular

Barrel Diameter: 13.00 ft

Barrel Material: Corrugated Steel

Embedment: 66.00 in

Barrel Manning's n: 0.0240 (top and sides)

Manning's n: 0.0320 (bottom)

Culvert Type: Straight

Inlet Configuration: Beveled Edge (1:1)

Inlet Depression: None

Culvert Data: Floodplain Overflow

Table 2 - Culvert Summary Table: Floodplain Overflow 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)

195.00 cfs

48.71 cfs 280.76 2.46 2.014 1- JS1t

1.62 1.85 3.03 3.02 3.40 5.10

254.00 cfs

65.07 cfs 281.17 2.87 2.283 1- JS1t

1.88 2.15 3.23 3.22 4.19 4.31

313.00 cfs

80.57 cfs 281.56 3.26 2.517 1- JS1t

2.10 2.40 3.39 3.38 4.89 4.18

372.00 cfs

96.38 cfs 281.95 3.65 2.748 1- JS1t

2.31 2.64 3.52 3.51 5.59 4.19

431.00 cfs

113.15 cfs 282.32 4.02 2.989 1- JS1t

2.52 2.87 3.64 3.63 6.30 4.26

490.00 cfs

130.91 cfs 282.69 4.39 3.250 1- S2n

2.74 3.10 2.76 3.74 10.32 4.35

549.00 cfs

149.47 cfs 283.04 4.74 3.534 1- S2n

2.96 3.32 2.98 3.84 10.68 4.44

608.00 cfs

168.55 cfs 283.39 5.09 3.841 1- S2n

3.18 3.54 3.20 3.94 11.01 4.54

670.00 cfs

188.97 cfs 283.75 5.45 4.192 1- S2n

3.41 3.75 3.43 4.03 11.32 4.65

726.00 cfs

207.44 cfs 284.07 5.77 4.530 1- S2n

3.62 3.94 3.64 4.11 11.57 4.75

785.00 cfs

226.70 cfs 284.41 6.11 4.906 5- S2n

3.84 4.12 3.86 4.20 11.80 4.84

Inlet Elevation (invert): 278.30 ft, Outlet Elevation (invert): 277.20 ft

Culvert Length: 62.01 ft, Culvert Slope: 0.0177

Culvert Performance Curve Plot: Floodplain Overflow

Water Surface Profile Plot for Culvert: Floodplain Overflow

Site Data - Floodplain Overflow

Inlet Station: 0.00 ft

Inlet Elevation: 278.30 ft

Outlet Station: 62.00 ft

Outlet Elevation: 277.20 ft

Number of Barrels: 1

Culvert Data Summary - Floodplain Overflow Barrel Shape: Circular

Barrel Diameter: 6.00 ft

Barrel Material: Corrugated Steel

Embedment: 0.00 in

Barrel Manning's n: 0.0240

Culvert Type: Straight

Inlet Configuration: Beveled Edge (1.5:1)

Tailwater Data for Crossing: Jean Creek

Table 2 - Downstream Channel Rating Curve (Crossing: Jean Creek) Flow (cfs) Water

Surface Elev (ft)

Velocity (ft/s)

Depth (ft) Shear (psf) Froude Number

195.00 280.23 3.02 5.10 1.70 1.46

254.00 280.43 3.22 4.31 1.81 1.00

313.00 280.59 3.38 4.18 1.90 0.87

372.00 280.72 3.51 4.19 1.97 0.80

431.00 280.84 3.63 4.26 2.04 0.77

490.00 280.95 3.74 4.35 2.10 0.74

549.00 281.05 3.84 4.44 2.16 0.73

608.00 281.15 3.94 4.54 2.21 0.72

670.00 281.24 4.03 4.65 2.26 0.71

726.00 281.32 4.11 4.75 2.31 0.71

785.00 281.41 4.20 4.84 2.36 0.70

Tailwater Channel Data - Jean Creek Tailwater Channel Option: Irregular Channel

Channel Slope: Irregular Channel

User Defined Channel Cross-Section Coord No. Station (ft) Elevation (ft) Manning's n 1 0.00 288.00 0.0550 2 30.00 280.11 0.0450 3 75.00 280.11 0.0320 4 76.00 277.21 0.0320 5 84.00 277.21 0.0320 6 85.00 280.11 0.0450 7 130.00 280.11 0.0550 8 160.00 288.00 0.0000

Roadway Data for Crossing: Jean Creek Roadway Profile Shape: Constant Roadway Elevation

Crest Length: 100.00 ft

Crest Elevation: 288.00 ft

Roadway Surface: Gravel

Roadway Top Width: 27.00 ft

HY-8 Culvert Analysis Report - Existing Conditions

Crossing Discharge Data

Discharge Selection Method: Specify Minimum, Design, and Maximum Flow

Minimum Flow: 195.00 cfs

Design Flow: 670.00 cfs

Maximum Flow: 785.00 cfs

Table 1 - Summary of Culvert Flows at Crossing: Jean Creek Existing Conditions

Headwater Elevation (ft)

Total Discharge (cfs)

Jean Creek Culvert Discharge (cfs)

Floodplain Overflow Discharge (cfs)

Roadway Discharge (cfs)

Iterations

283.26 195.00 145.50 49.50 0.00 5

284.03 254.00 179.32 74.66 0.00 3

284.73 313.00 210.55 102.44 0.00 3

285.45 372.00 238.66 133.35 0.00 4

286.12 431.00 259.47 161.33 9.96 7

286.34 490.00 266.22 170.38 53.24 6

286.52 549.00 271.24 177.09 100.44 5

286.67 608.00 275.52 182.75 149.59 5

286.81 670.00 279.46 187.97 202.13 4

286.93 726.00 282.73 192.24 250.70 4

287.05 785.00 285.94 196.42 302.36 4

286.00 412.66 256.01 156.65 0.00 Overtopping

Rating Curve Plot for Crossing: Jean Creek Existing Conditions

Culvert Data: Jean Creek Culvert

Table 1 - Culvert Summary Table: Jean Creek Culvert

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)

195.00 cfs 145.50 cfs 283.26 5.23 5.552 2-M2c 4.39 3.27 3.27 2.82 9.22 4.28

254.00 cfs 179.32 cfs 284.03 6.07 6.319 7-M2c 6.00 3.65 3.65 3.00 9.95 3.98

313.00 cfs 210.55 cfs 284.73 6.91 7.019 7-M2c 6.00 3.97 3.97 3.15 10.61 3.97

372.00 cfs 238.66 cfs 285.45 7.74 7.659 7-M2c 6.00 4.23 4.23 3.27 11.20 4.04

431.00 cfs 259.47 cfs 286.12 8.41 8.150 7-M2c 6.00 4.41 4.41 3.39 11.64 4.14

490.00 cfs 266.22 cfs 286.34 8.63 8.315 7-M2c 6.00 4.47 4.47 3.49 11.79 4.25

549.00 cfs 271.24 cfs 286.52 8.81 8.439 7-M2c 6.00 4.51 4.51 3.59 11.90 4.36

608.00 cfs 275.52 cfs 286.67 8.96 8.546 7-M2c 6.00 4.54 4.54 3.69 11.99 4.47

670.00 cfs 279.46 cfs 286.81 9.10 8.646 7-M2c 6.00 4.58 4.58 3.78 12.08 4.59

726.00 cfs 282.73 cfs 286.93 9.22 8.729 7-M2c 6.00 4.60 4.60 3.86 12.15 4.69

785.00 cfs 285.94 cfs 287.05 9.34 8.813 7-M2c 6.00 4.63 4.63 3.94 12.22 4.79

Inlet Elevation (invert): 277.71 ft, Outlet Elevation (invert): 277.50 ft

Culvert Length: 40.00 ft, Culvert Slope: 0.0051

Culvert Performance Curve Plot: Jean Creek Culvert

Water Surface Profile Plot for Culvert: Jean Creek Culvert

Site Data - Jean Creek Culvert

Inlet Station: 0.00 ft

Inlet Elevation: 277.71 ft

Outlet Station: 40.00 ft

Outlet Elevation: 277.50 ft

Number of Barrels: 1

Culvert Data Summary - Jean Creek Culvert

Barrel Shape: Circular

Barrel Diameter: 6.00 ft

Barrel Material: Corrugated Steel

Embedment: 0.00 in

Barrel Manning's n: 0.0240

Culvert Type: Straight

Inlet Configuration: Thin Edge Projecting (Ke=0.9)

Culvert Data: Floodplain Overflow

Table 2 - Culvert Summary Table: Floodplain Overflow

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)

195.00 cfs 49.50 cfs 283.26 2.63 0.773 1-S2n 1.51 1.97 1.55 2.82 9.58 4.28

254.00 cfs 74.66 cfs 284.03 3.40 1.465 1-S2n 1.88 2.44 1.93 3.00 10.66 3.98

313.00 cfs 102.44 cfs 284.73 4.10 2.252 1-S2n 2.24 2.88 2.31 3.15 11.54 3.97

372.00 cfs 133.35 cfs 285.45 4.82 3.190 1-S2n 2.61 3.31 2.70 3.27 12.33 4.04

431.00 cfs 161.33 cfs 286.12 5.49 4.107 5-S2n 2.94 3.64 3.04 3.39 12.93 4.14

490.00 cfs 170.38 cfs 286.34 5.72 4.418 5-S2n 3.04 3.74 3.14 3.49 13.11 4.25

549.00 cfs 177.09 cfs 286.52 5.89 5.248 5-S2n 3.12 3.81 3.23 3.59 13.22 4.36

608.00 cfs 182.75 cfs 286.67 6.04 5.421 5-S2n 3.19 3.87 3.29 3.69 13.32 4.47

670.00 cfs 187.97 cfs 286.81 6.18 5.584 5-S2n 3.25 3.92 3.36 3.78 13.42 4.59

726.00 cfs 192.24 cfs 286.93 6.30 5.719 5-S2n 3.31 3.96 3.41 3.86 13.50 4.69

785.00 cfs 196.42 cfs 287.05 6.42 5.853 5-S2n 3.36 4.00 3.45 3.94 13.58 4.79

Inlet Elevation (invert): 280.63 ft, Outlet Elevation (invert): 279.26 ft

Culvert Length: 44.50 ft, Culvert Slope: 0.0308

Culvert Performance Curve Plot: Floodplain Overflow

Water Surface Profile Plot for Culvert: Floodplain Overflow

Site Data - Floodplain Overflow

Inlet Station: 0.00 ft

Inlet Elevation: 280.63 ft

Outlet Station: 44.48 ft

Outlet Elevation: 279.26 ft

Number of Barrels: 1

Culvert Data Summary - Floodplain Overflow

Barrel Shape: Circular

Barrel Diameter: 5.00 ft

Barrel Material: Corrugated Steel

Embedment: 0.00 in

Barrel Manning's n: 0.0240

Culvert Type: Straight

Inlet Configuration: Beveled Edge (1.5:1) (Ke=0.2)

Tailwater Data for Crossing: Jean Creek Existing Conditions

Table 2 - Downstream Channel Rating Curve (Crossing: Jean Creek Existing Conditions)

Flow (cfs) Water Surface Elev (ft)

Velocity (ft/s) Depth (ft) Shear (psf) Froude Number

195.00 280.33 2.82 4.28 1.59 1.13

254.00 280.51 3.00 3.98 1.69 0.89

313.00 280.65 3.15 3.97 1.77 0.81

372.00 280.78 3.27 4.04 1.84 0.76

431.00 280.89 3.39 4.14 1.90 0.74

490.00 281.00 3.49 4.25 1.96 0.72

549.00 281.10 3.59 4.36 2.02 0.71

608.00 281.19 3.69 4.47 2.07 0.70

670.00 281.28 3.78 4.59 2.12 0.70

726.00 281.36 3.86 4.69 2.17 0.69

785.00 281.45 3.94 4.79 2.21 0.69

Tailwater Channel Data - Jean Creek Existing Conditions

Tailwater Channel Option: Irregular Channel

Channel Slope: Irregular Channel

User Defined Channel Cross-Section

Coord No. Station (ft) Elevation (ft) Manning's n

1 0.00 288.00 0.0550

2 30.00 280.11 0.0450

3 75.00 280.11 0.0320

4 76.00 277.50 0.0320

5 84.00 277.50 0.0320

6 85.00 280.11 0.0450

7 130.00 280.11 0.0550

8 160.00 288.00 0.0000

Roadway Data for Crossing: Jean Creek Existing Conditions

Roadway Profile Shape: Constant Roadway Elevation

Crest Length: 100.00 ft

Crest Elevation: 286.00 ft

Roadway Surface: Gravel

Roadway Top Width: 27.00 ft

SCALE IN FEET

10 0 10 20 30 40

OUTLETINLETPIPEHYDRAULIC INFORMATION

0 20 40 60 8020406080

LENGTH: 82 ft

PIPE SLOPE: 0.0050 ft/ft

HEADWALL: Conc./Riprap

FLOWLINE SLOPE: 0.0050 ft/ft

100 120100120140

Q : 195 CFS

Q : 670 CFS

BANKFULL CHANNEL WIDTH: 10.0 ft

TYPE: Struct. Plt. Pipe SPAN: 13 ft RISE: 13 ft

LOWER BEVEL HEIGHT: 6.5 ft LOWER BEVEL HEIGHT: 6.5 ft

BEVEL: 1.5h : 1v

HEADWALL: Conc./Riprap

BEVEL: 1.5h : 1v

Q :785 CFS

INV N/E/EL: 2368669.67/1619350.15/272.12' /1619364.80/271.71INV N/E/EL: 2368588.99

WALL THICKNESS: NA

:1

Existing ground

Flow

Remove exisiting 72" CMP

HW : 284.4 ft

Jean Creek

N

LC

OHW : 280.8 ft

Slope 0.50%

Line to be constructed

BURIAL DEPTH: 5.5 ft BURIAL DEPTH: 5.5 ft

1:1

New culvert centerline structural plate pipe arch replace with 13' diameter

212+58.15

212+53.54, 39.34 RT

PLAN AND PROFILE

JEAN CREEK CULVERT

method B, class 3

Placed riprap method B, class 3

Placed riprap

Concrete collar Concrete collar detail Sheet G.13per

Backfill with streambed material

FOOTNOTE:

See Sheet G.11 for riprap details.[1]

G.2

STATE PROJECT

NUMBER

SHEET

AK FWS KNA 1192(1)

V

B e v a n

J N e ig h o r n

/2

/2

C h e c k e d b y

D e s ig n e d b y

In t_ ft

D c p w w o r k \d

\a k r k e n a i1 h .d g n

Road centerline

Channel elev. 277.62

Channel elev. 277.21

Channel flowline

Road grade

:4

A

M

J u ly

Flow

212+63.08, 42.10 LT

with 72" CMP

Replace exisiting 60" CMP

Concrete collar

Concrete collar method B, class 3

Placed riprapmethod B, class 3

Placed riprap per detail sheet G.15

Install rock weirs at 40' spacing

Begin channel grading End channel grading

End channel grading

Begin channel grading

Cut and fill limits (typ.)

1:1 2'

TYPICAL SECTION

CHANNEL GRADING

4" depth and seed

Place topsoil, [1]

[1]

[1]

[1] [1]

.5

6'

10' Bankfull width

NOTE:

FOOTNOTE:

DETAILS

RIPRAP HEADWALL

Sl op e

PIPE BEVEL DETAIL

Sl op e

SKEW ANGLE DIAGRAM

c e n te r li n e

R o a d w a y

Cu lv er t ce nt er lin e

BOP

EOP

(DIAMETER OR SPAN GREATER OR EQUAL TO 48-INCHES)

(DIAMETER OR SPAN LESS THAN 48-INCHES)

.2

D o r R

.2

D o r R o r R is e

R

D ia m e te r

D o r R is e

R

D ia m e te r

D

W

Sl op e

FRONT VIEW SIDE VIEW

[2

24" shown in the plans

Streambed material where shown in the plans

Streambed material where

V a ri a b le R is e

W2

Variable W2 o r R is e

R

D ia m e te r

V a r ia b le

Placed riprap, class 3

Placed riprap, class 3

[3

" m in geotextile, class 1, type C

Separation and stabilization

Manufacturer's standards

0.25 D or R or per the

Optional

Skew

B e v n

N e ig h o r

/2

/2

C h e c k e d b y

D e s ig n e d b y

G.11

STATE PROJECT

NUMBER

SHEET

In t_ ft m y f il e s \p w p r o d u c ti o n

\d

\m t-a e z .d g n

AK FWS KNA 1192(1)

:5

A u g u s t beneath and at all sides of placed riprap.

Place earthwork geotextile between riprap and existing ground, Earthwork geotextile, type II-C is subsidiary to 251.

Contractor to field verify all invert elevations, prior to installation.

3.

2.

1.

shown on site specific details, whichever is greater.

Construct riprap end treatment to a thickness of 36-inches or as[3]

Riprap end treatment slope to match roadway embankment slope.[2]

Bevel to match roadway embankment.[1]

RIPRAP END TREATMENT

[1]

[1]

B e v

N e ig h o

/2

/2

C h e c k e d b y

D e s ig n e d b y

G.12

STATE PROJECT

NUMBER

SHEET

In t_ ft p w w o r k \d

\a k r k e n a i1 h .d g n

AK FWS KNA 1192(1)

:4 a y

SECTION VIEW

ANCHOR BOLT DETAIL

1.5

3'-0"

TYPICAL SECTION

THRU COLLAR

CONCRETE COLLAR

ISOMETRIC VIEW

3'-0"

3'

Sp an

3'

LC

Culvert crown

2' min. lap splice

#4 Reinf (6 total)

Culvert invert galvanized " Dia.4 bolt design - 4" hook

Acceptable anchorStructural plate pipe

18" o.c. See detail " Anchor bolt @4

#4

#4 stirrups m in

2' min. lap splice

#4 Reinf (6 total)

6" min.

To bedrock or 3' max.

To bedrock or 3' max.

COLLAR DETAILS

REINFORCED CONCRETE

LARGE CULVERT

SECTION A-A

PLAN

NOTE:

FOOTNOTE:

3.

2.

1.

Pipe arch culvert

W

Streambed sediment

Streambed cobble

Pipe arch culvert wall

Box culvert wall

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

streambed cobble, and bank stone gradations.

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

Channel flowline

Streambed sedimentRound pipe culvert wall Streambed top

Round culvert

Culvert wall

LC

Flow

BB

A where specified on plan per detail Sheet G.14

Sediment retention sill on plan where specified detail Sheet G.15

Rock weir per culvert boulder within

Fish passage where specified on plan per detail Sheet G.14

Sediment retention sill specified on plan boulder where

Fish passage

NO SCALE

Streambed Material.

Infill informational quantities are incidental to ITEM 64704-1000 [4] dimension.

smallest 4 3 Embed fish passage boulders within active channel [3] sediment where listed in the infill quantities table.

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

Slope streambed aggregate towards flowline to ensure[1]

[1]Channel flowline

[2]Bank stone

[2]Bank stone

TREATMENT

STREAM CULVERT

SIMULATED

A Flow

SECTION B-B

(typ.)

36" min.

Streambed cobble

Culvert outlet where specified on plan per detail Sheet G.14

Sediment retention sill

[3]within culvert

Fish passage boulder

Streambed sediment plan sheet or Length on

LC

specified on plan

Sheet G.15 where

Rock weir per detail outlet

Culvert

LOCATION

(FT)

X

(CUYD)

COBBLE

STREAMBED

(CUYD)

SEDIMENT

STREAMBED

(CUYD)

STONE

BANK

GRADATION

COBBLE

STREAMBED

(FT)

W

MITIGATION

FISH PASSAGE BOULDER

(IN)

DIA. NO.

[4]STREAMBED MATERIAL

TOTAL

B e v

N e ig h o

/2

/2

C h e c k e d b y

D e s ig n e d b y

G.13

STATE PROJECT

NUMBER

SHEET

In t_ ft m y f il e s \p w p r o d u c ti o n

\d

\m t-a e w

.d g n

AK FWS KNA 1192(1)

:4

A u g u s t

JEAN CREEK NA 10

LOWER OHMER CREEK NA 7

UNNAMED CREEK 3.8 6.7

D

D

D

(IN)

BD

BD/3

3% (typ.)

Slope

B D

W

X (typ.)

X (typ.)

4' match rock weir spacing

Stagger fish boulders each side and d e p th

B u r ia l

B u r ia l d e p th

Flow

F lo wA

A

(in)

DIAMETER

FOOTER ROCK

TOP ROCK AND

(no.)

QUANTITY

ROCK WEIR

MITIGATION

ROCK WEIR

(ft)

B

(ft)

[5] Z

(ft)

W

LOCATION

ELEVATION

PLAN

SECTION A-A

DETAIL

ROCK WEIR

NO SCALE

FOOTNOTE:

Align footer rocks flush against bed retention sills inside culvert. [5] and stable foundation for the top rocks.

Place footer rocks close together to create a tightly packed[4] streambed material.

Fill voids in top rock and footer rock with specified[3]

Space top rocks in center 1/3 only.[2]

Orient top rocks to deflect water towards center of stream.[1]

[4] [3]Footer rock

Top rock

Bottom of channel

Bottom of channel

[4] [3]Footer rock high water level

Ordinary normal low flow

Edge of water

Control point

[2] [1] [2] [1]

[2]

[3] [2]Top rock

[2]

[2] [2] [2]

[2] streambed material elevation or top of

Original streambed

[4] [3]Footer rock

[3]Top rock water level

Ordinary high

B e v

N e ig h o

/2

/2

C h e c k e d b y

D e s ig n e d b y

G.15

STATE PROJECT

NUMBER

SHEET

In t_ ft m y f il e s \p w p r o d u c ti o n \d

\m t-a e y .d g n

AK FWS KNA 1192(1)

:5

A u g u s t

JEAN CREEK 10.0 1.5 5.5 3

LOWER OHMER CREEK 7.0 1.0 4.5 4

UNNAMED CREEK 6.6 1.2 3.3 19

Z

D o w n s tr e a m f r o m c o n tr o l)

BWB

B W3

W 3

W3

B

W3

VAP

Existing ground

Roadway centerline

2000 50 100 15050100150200

Jean Creek

Section 703. — AGGREGATE

703.18 Furnished Streambed Material. (Added Subsection).

Streambed material consists of streambed sediment and streambed cobbles (class A, B, C, D, or E as specified on the plans) with volumes of each specified on the plans. Provide a uniform mixture.

Furnish material consisting of hard, durable, free from seams, cracks, and other defects conforming to the following:

(a) Durability index, AASHTO T 210

(1) Course aggregate 35 min.

(2) Fine aggregate 35 min.

(b) Apparent specific gravity, AASHTO T 85 2.55 min.

(c) Los Angles abrasion, AASHTO T 96 50% max.

(d) Gradation, Streambed Sediment. Furnish material meeting the gradation requirements of Table 703-13. Conserve round or sub-round material from the culvert and roadway excavation meeting the requirements of Table 703-13 to use as streambed sediment.

Table 703-13 Streambed Sediment Gradation

Sieve Size

Percent by Weight Passing Designated Sieve

(AASHTO T 27 and T 11)

3 ½ inch 100

3 inch 80 – 90

1 ½ inch 55 – 65

¾ inch 40 – 50

No. 4(1) 15 – 25

No. 10 15 min.

(1) No more than 0.2 percent woody debris retained.

(e) Gradation, Streambed Cobbles. Furnish material meeting the requirements of Table 703-14. Conserve round or sub-round material from the roadway excavation meeting the requirements of Table 703-14 to use as streambed cobbles.

Table 703-14 Streambed Cobbles Gradation(1)

Nominal Size

Percent less than the nominal size Class

A B C D 18” 100 12" 60-70 10" 100 8" 100 75-80 30-40 6" 100 50-60 10-20 5" 65-75 4" 65-75 30-40 3" 35-45 25-35 0-10 2" 35-45

1 ½" ¾" 10-15 10-15

(1) Grading of the cobbles will be by visual inspection of material before it is placed, and if directed by the CO, by placing material on a flat surface and sorting and measuring a sampling of the cobbles..

Note: Approximate size can be determined by taking the average dimension of the three axes of the rock; length, width, and thickness by use of the following calculation:

𝐿𝐿𝐿𝐿𝐿𝐿𝐿𝐿𝐿𝐿ℎ + 𝑊𝑊𝑊𝑊𝑊𝑊𝐿𝐿ℎ + 𝑇𝑇ℎ𝑊𝑊𝑖𝑖𝑖𝑖𝐿𝐿𝐿𝐿𝑖𝑖𝑖𝑖

= 𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝑊𝑊𝐴𝐴𝐴𝐴𝐿𝐿𝐿𝐿 𝑆𝑆𝑊𝑊𝑆𝑆𝐿𝐿

Project:

Location/Stream:

New Stream Channel Design (Culvert, Rock Ramp)

FINE 50%

Using Corps of Engineers Equations - FHWA Circular on Development in the River System - Page 6.25. COARSE 50% FHWA NHI 01-004; River Engineering for Highway Encroachments, 2001 http://www.fhwa.dot.gov/engineering/hydraulics/library_arc.cfm?pub_number=8&id=20

YELLOW ARE INPUTS

Safety Factor 1.2 Stability Coefficient for Incipient Failure 0.36 (0.36 round rock, 0.3 angular rock) Vertical Velocity Distribution Coeff 1.00 (1.0 for straight channels) Blanket Thickness Coeff 1 (1xD100 or 1.5 or D50 max, whichever is greater) Local depth of flow 4.03 ft for 50 year event Unit Weight of water 62.4 lb/ft^3 assumed Unit weight of rock 165 lb/ft^3 assumed Local depth-average velocity 9.48 ft/s from 50-year event avg. velocity in pipe Side Slope correction factor 1 Gravitational Acceleration 32.2 ft/s^2 D85/D15 1.8 (1.7-5.2) D50/D30 1 Note: This method is based on the minimum D30 size Riprap Design Method - Selecting Proper Gradation, Page 131.

Design Hydrology and Sedimentology for Small Catchments, Haan, Barfield and Hayes, 1981.

D15 0.3 ft 4.0 inches D30 0.6 ft 8.0 inches D50 0.7 ft 9.0 inches D85 1.2 ft 15.0 inches

D100 1.4 ft 18.0 inches

Using D50 size, used FHWA circular for Rip Rap design to spec out D100, D85 and D15.

D100 = 2.0D50

Fuller-Thompson Estimating for Maximum Density: D100 (inches) 18.0 Method Adapted from US Forest Service Stream Simulation Guidelines D30 8.0 Stability (D30):

D30 Req'd 8.0

YELLOW ARE INPUTS COARSE FINES

Custom Fine Aggreg. Combined %F-T EQN Check Coarse Material Design -D30 Required p RELATIVE % = 0.50 0.50 1.0000 Riprap D30 Riprap Req 8.0

Size (inches) Sieve Size % Passing % Passing % Passing % Passing % Passing D30 Size = 8.0 54 54 in 1.00 1.00 100% 173% 100% No OK 48 48 in 1.00 1.00 100% 163% 100% No 44 44 in 1.00 1.00 100% 156% 100% No 42 42 in 1.00 1.00 100% 153% 100% No 36 36 in 1.00 1.00 100% 141% 100% No 30 30 in 1.00 1.00 100% 129% 100% No 24 24 in 1.00 1.00 100% 115% 100% No 18 18 in 1.00 1.00 100% 100% 100% No 12 12 in 0.65 1.00 83% 82% 65% No 8 8 in 0.30 1.00 65% 67% 30% 8.00 6 6 in 0.10 1.00 55% 58% 10% 6.00 3 3 in 0.00 0.85 43% 41% 0% 3.00

1.5 1.5 in 0.00 0.60 30% 29% 0% 1.50

0.75 0.75 in 0.00 0.45 23% 20% 0% 0.75

0.187 #4 0.00 0.20 10% 10% 0% 0.19

0.0787 #10 Sand 0.00 0.15 8% 7% 0% 0.08

Gradation values should be within +/-5% of this gradation (Rice) AND we need to have at least 5% sand size (#10) or smaller (Forest Service) in the combined gradation

DATA for Graph & Fuller-Thomson Eqn Size (in) Combined % pa F-T equation

54.000 100% 173%

48.000 100% 163%

44.000 100% 156%

42.000 100% 153%

36.000 100% 141%

30.000 100% 129%

24.000 100% 115%

18.000 100% 100%

12.000 83% 82%

8.000 65% 67%

6.000 55% 58%

3.000 43% 41%

1.500 30% 29%

0.750 23% 20%

0.187 10% 10%

0.079 8% 7%

OK

MATERIAL PROPORTIONS

AK FWS Kenai 1102(1) - Skilak Lake Road

Jean Creek Culvert

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0.010 0.100 1.000 10.000 100.000

P as si ng

Particle Size

Design

Fuller‐Thomson

YELLOW ARE INPUTS

Desired tolerance (+/-): 5%

SIEVE % PASSING

18 in 1.00 12 in 1.00 8 in 1.00 6 in 1.00 3 in 0.8 to 0.9

1.5 in 0.55 to 0.65

0.75 in 0.4 to 0.5

#4 0.15 to 0.25 #10 Sand 0.15 min

Desired tolerance (+/-): 5%

SIZE % PASSING

54 in 1.00 48 in 1.00 44 in 1.00 42 in 1.00 36 in 1.00 30 in 1.00 24 in 1.00 18 in 1.00 12 in 0.6 to 0.7 8 in 0.3 to 0.4 6 in 0.1 to 0.2

3 in 0 to 0.1

TABLE 1

FINE MATERIAL

TABLE 2

COARSE MATERIAL

Tailwater Channel Data - Jean Creek

Roadway Data for Crossing: Jean Creek