tillicum fan habitat restoration concepts...

Tillicum Fan Habitat Restoration Concepts ReportSubmiTTed ToYakama Nation Fisheries

MaRCh 2017

Tillicum Fan Habitat Restoration Concepts Report

MaRCh 2017

SubmiTTed ToYakama Nation Fisheries 401 Fort Road Toppenish, Wa

prepared byInter-Fluve, Inc.501 Portway ave, Suite 101hood River, OR 97031 (541) 386-9003


i

Table of Contents

INTRODUCTION ................................................................................................................................... 1

Overview .......................................................................................................................................... 1

Project Area Description ................................................................................................................... 1

Goals and objectives ........................................................................................................................ 2 Regional Habitat Objectives and Priorities ........................................................................................... 2

SITE CONDITIONS AND ANALYSIS ......................................................................................................... 3

Site Survey and Data Collection ........................................................................................................ 3

Geomorphology ............................................................................................................................... 6

Hydrology ........................................................................................................................................ 7

Hydraulic Modeling .......................................................................................................................... 8

PRELIMINARY DESIGN CRITERIA ........................................................................................................... 9 Habitat .................................................................................................................................................. 9 Geomorphology/Hydrology .................................................................................................................. 9 Engineering and Risk ............................................................................................................................. 9 Construction Impacts .......................................................................................................................... 10

CONCEPT DESIGNS ............................................................................................................................. 10

Concept 1: Fan Swale Extending to Mad River ................................................................................ 12

Concept 2: Short Fan Swale Extending to Mad River Relic Channel ................................................. 13

Concept 3: Long Fan Swale Extending to Mad River Relic Channel .................................................. 14

Designer’s notes on configurations ................................................................................................. 14

REFERENCES ....................................................................................................................................... 15

Attachments – Plans and estimates

Appendix 1 – Stream substrate pebble count data

Appendix 2 – Stream hydrology

Appendix 3 – Hydraulic modeling output


March 2017 1

1. Introduction

OVERVIEW

This report presents field investigations and development of concepts for opportunities to

enhance stream processes and aquatic habitat at the Tillicum Creek Fan project area. The project

proposes to improve stream processes and riparian conditions to enhance aquatic habitats for

Endangered Species Act (ESA) listed Chinook salmon (Oncorhynchus tshawytscha) and steelhead

(Oncorhynchus mykiss).

PROJECT AREA DESCRIPTION

Tillicum Creek is a tributary to the Mad River at River Mile 1.92, approximately 10 miles

northwest of Entiat, in Chelan County, Washington, near the intersections of Mad River Road

(119A) and Forest Service Roads 5700 and 5800. The Mad River is tributary to the Entiat River

near the unincorporated community of Ardenvoir. Tillicum Creek has formed an alluvial fan

that terminates along 560 feet of the Mad River and extends up the Tillicum Valley 700 feet

where Tillicum Creek flows out of a confined valley and expands radially across the wider fan

surface. The fan is bounded on both sides by steep valley walls. Forest Road 5800 runs along

the toe of the north valley wall and Tillicum Creek runs along the toe of the south valley wall.

The project area of Tillicum Creek and fan and right bank of Mad River encompasses

approximately 3.57 acres. The entire project area is located on land owned by the U.S. Forest

Service.

Tillicum Creek is entrenched and confined in some locations by a levee, preventing hydrologic

connection to the full width of the historic fan limits. The fan is predominantly open field that

is grazed seasonally. The banks of Tillicum Creek and Mad River are vegetated with riparian

trees.


March 2017 2

Figure 1. Location of the Tillicum Creek watershed and the project area.

GOALS AND OBJECTIVES

Regional Habitat Objectives and Goals

Regional objectives for salmonid habitat protection and restoration in the Upper Columbia

Region have been evaluated and summarized in the document A Biological Strategy to Protect and

Restore Salmonid Habitat in the Upper Columbia Region (2014) by the Upper Columbia Salmon

Recovery Board (UCSRB) Regional Technical Team (RTT). This Biological Strategy is part of the

Upper Columbia Spring Chinook Salmon and Steelhead Recovery Plan (UCSRB 2007). It

recommends region‐wide biological considerations and approaches for salmonid habitat

restoration and protection actions. The RTT guides the development and evaluation of salmonid

recovery projects within the Upper Columbia Region.

The Biological Strategy has identified several assessment units within the Entiat River

watershed, including the Mad River assessment unit which includes the Tillicum Creek fan

project area. The Mad River is a Tier II priority and the project area is within an area known to

provide spawning and rearing habitat for steelhead and rearing habitat for spring Chinook.


March 2017 3

The Biological Strategy notes factors affecting habitat conditions to include historical sheep

grazing and timber harvest practices, which have both increased upland erosion and sediment

delivery to the stream. Further, the Mad River Road constricts the main stem channel at the

project area. Ecological concerns include:

Channel structure and form

Sediment conditions

Riparian conditions

Food

Habitat quantity.

The primary project goal is to improve stream process and associated habitats along the

Tillicum Fan by creating improved hydrologic connectivity of Tillicum Creek with its fan, and

Mad River with its floodplain, along the distal end of the Tillicum fan. Improved stream

processes will enhance habitat complexity, create wetland and riparian vegetative communities,

and possibly access to ground water inflow.

2. Site Conditions & Analysis

SITE SURVEY AND DATA COLLECTION

Topographic and bathymetric data were collected October 2, 2016 using total station survey

equipment. The data collection focused on capturing channel cross sections for hydraulic

modeling, as well as topography of the fan for mapping and concept designs. Temporary

benchmarks were placed throughout the project site for future reference. Survey is based on a

project relative datum.


March 2017 4

Figure 2. Looking downstream (east) at Tillicum fan. Tillicum Creek along right edge. Mad River along far end of field.

Five soil pits were excavated on the Tillicum Fan on November 8, 2016 at locations shown on

Figure 3. Soil profiles were documented by Inter‐Fluve staff and reported in a separate

memorandum. Soils generally consist of fine soils of varying depths over gravel and cobble and

are dry or have low rates of groundwater inflow. Perforated PVC piezometers with water level

data loggers were installed in Pits 1 through 4. Data loggers will be downloaded in the spring

of 2017.


March 2017 5

Figure 3. Locations of 2016 soil pits

Soil types mapped by the USDA NRCS are fine loam in the valley (Figure 4). The two primary

soil types in the Tillicum Fan project area include: #37 ‐ Billyridge gravelly sandy loam, which is

a well‐drained soil that forms in alluvial fans; and, #33 ‐ Ardenvoir stony fine sandy loam which

is a well‐drained soil that is generally formed by colluvium parent material from adjacent

mountain slopes.


March 2017 6

Figure 4. NRCS soils types within the Tillicum fan area (USDA NRCS 2017).

GEOMORPHOLOGY

The Tillicum Creek and fan is confined by valley wall along the south edge and Forest Road

5800 and valley wall along the north edge. The basal end of fan is about 700 feet upstream of

the confluence with the Mad River. The distal end of the fan is the right bank of the Mad River.

With few exceptions, riparian vegetation is robust along the banks of Tillicum Creek and the

Mad River. The Tillicum fan surface is former pasture and currently fenced. Figures 2 and 3

provide an overview of site conditions.

Tillicum Creek average grade is 2.5% along the project reach. The creek is confined through

entrenchment and periodic levees along the left bank. The right valley wall is in close proximity

to the right bank with narrow 10 to 30‐foot wide flood prone benches between the creek and

valley toe. Riparian vegetation is dense. The stream bed grade is partly controlled by colluvially

derived lag material and woody debris that temporarily stores sediment. The stream banks are

generally stable with vegetated banks along much of the project reach. Some banks have been

stabilized with concrete rubble or stone armoring. Two locations vegetated by reed canary

grass have undercut their banks and are migrating laterally.


March 2017 7

Occurrences of self‐formed channel sections and gravel bars are limited but do exist. Near the

upstream end of the project reach, the creek has apparently hydrologically connected narrow

vegetated flood benches (Figure 5). Approximately 80 feet upstream from the confluence with

the Mad River is a gravel bar along the inside of a bend that provides a reference condition for

future channel design. One pebble count was conducted along this self‐formed gravel bar

indicative of developing OHW flood prone channel surface. Gradation of the sampled gravel

bar material includes D16, D50, and D84 were 22mm, 64mm, and 128mm, respectively.

Summary data are included in Appendix 1. Pebble count data will be used for channel design

in future design phases.

Figure 5. Looking downstream along Tillicum Creek at typical self‐formed channel dimensions.

HYDROLOGY

The Tillicum Creek watershed (Figure 1) encompasses approximately 22.25 square miles. It

flows into the Mad River at approximately RM 1.9, which discharges to the Entiat River near the

community of Ardenvoir. The Entiat River discharges to the Columbia River near Entiat, WA.

Tillicum Creek watershed elevations range from about 1,400 feet up to about 5,700 feet. Mean

annual precipitation in the basin is approximately 35 inches. Tillicum Creek has a snowmelt‐


March 2017 8

driven hydrograph with low flows in late summer and peak stream flows occurring during

snow melt in spring and early summer. Runoff timing and duration are affected by ambient air

temperatures, snowpack mass, and the distribution of the season’s snowpack.

No gage data exist for Tillicum Creek, and no flow measurement data on the creek were

available for this study. A USGS gage exists on the Entiat River near Ardenvoir, but is of

limited use for detailing Tillicum Creek hydrology. Thus, recurrence flows were calculated for

Tillicum Creek using USGS regression equations (Mastin, 2016) and are summarized in Table 1.

Calculations are included in Appendix 2.

Table 1. Flood recurrence flows for Tillicum Creek.

Recurrence Interval (years)

Peak Discharge (cfs)

2 132

10 312

25 429

50 533

100 640

HYDRAULIC MODELING

Existing channel and floodplain hydraulics were simulated using the U.S. Army Corps of

Engineers Hydraulic Engineering Center River Analysis System (HEC‐RAS 5.0.3; USACE 2016).

HEC‐RAS is a computer program that models the hydraulics of water flow through natural

rivers and other channels. The model was run in one‐dimensional steady state mode. Model

results include estimates of flow depth, velocity, energy and extents of inundation for various

flow conditions.

The model geometry for existing conditions cross sections were developed using topographic

and bathymetry data obtained from the Inter‐Fluve survey completed in October 2016. Cross

sections extend from Forest Service Road 5800, through the fan and channel to the south valley

wall. The 2‐, 5‐, 10‐, 25‐, 50‐, and 100‐year recurrence interval floods summarized in Table 1

were modeled, as well as several flows less than the 2‐year event. Values for Manning’s n

coefficient of hydraulic roughness were initially set at 0.07 for the floodplain and 0.040 for the

channel based on professional judgement. The model was run in mixed mode to account for

possible subcritical and supercritical flow conditions. Upstream and downstream boundary

conditions were set at critical depth. Model results for existing conditions are included in

Appendix 3.

Cross sectional geometries from survey data where self‐formed floodplain benches or gravel

bars were present and HEC‐RAS inundations were used to estimate bank full flow to be


March 2017 9

approximately 80 cfs (~1.25‐year event). Corresponding average bank full channel cross section

is 12 to 14ft wide by about 1ft deep. Proposed conditions were not modeled at this conceptual

level and will be included as part of later phases of design.

The FEMA flood insurance rate map for Chelan County Washington (unincorporated areas),

Community Panel 530015 0375A, effective date of February 4, 1981, indicates that the base flood

delineation for the Mad River stops well short of the project area. Other than the NF 5800 road

bridge at the upstream, northeast corner of the project area, the closest infrastructure to the

project includes downstream residences with the closest being 0.9 miles downriver which

includes a house with private bridge. Project impacts on Mad River hydraulic conditions will

not extend downstream.

3. Preliminary Design Criteria A suite of preliminary design criteria are outlined below to guide development of concepts

including: 1) Habitat, 2) Geomorphology/Hydrology, 3) Engineering and Risk, and 4)

Construction Impacts.

Habitat

Promote natural habitat‐forming processes to the maximum extent practicable

Increase floodplain inundation

Increase in‐stream and floodplain habitat quality and quantity for steelhead and

Chinook salmon rearing at a range of flows

Design habitat elements that have low risk of creating fish passage barriers

Geomorphology/Hydrology

Design channels and floodplains that are consistent with current and projected

hydrologic and geomorphic regimes

Promote dynamic habitat‐forming processes

Maintain sediment transport continuity to maximize design life and reduce in‐filling

Promote sediment sorting

Engineering and Risk

Do not increase flooding or erosion risk to public or private infrastructure

Provide adequate ballasting of placed logs to withstand high flows that overtop the

structures (i.e. compensate for buoyancy)

Minimize risk to river users. The only identified recreational use of Tillicum Creek and

the Mad River is camping and day use along the floodplain and banks near the roads


March 2017 10

Construction Impacts

Choose channel alignments that take advantage of gaps in riparian vegetation to protect

existing mature vegetation.

Minimize impacts to existing mature vegetation that is providing shade to Tillicum

Creek and the Mad River

Maximize shading of Tillicum Creek

4. Concept Designs This site is suitable for a project that provides enhanced floodplain connection and habitat

complexity by excavating in the field area. New channel patterns can be formed on the alluvial

fan to replicate fluvial signatures typical of dynamic fan and confluence processes.

The three enclosed concepts were developed to represent a range of restoration intensities and

construction impacts. Each concept would create diverse and complex habitats through

hydrologically connected floodplains and high flow channels, backwater areas and wetlands.

All three concepts leave Tillicum Creek in its current alignment and create a fan swale adjacent

to the creek to increase flood prone riparian areas. Portions of bankfull and greater flows would

access these areas, providing habitat opportunities while reducing hydraulic stress in the creek.

The fan swale would be inset into a floodplain bench, and placement of woody debris would

further improve habitat, geomorphic function, and natural aesthetic. The variation in terrain

and seasonal contact with surface water and groundwater will support diverse wetland and

riparian vegetation communities.


March 2017 11

Alternatives one and two add a flood channel off the Mad River that would further increase

habitat, diverse flow patterns, and wetland mosaic. High flows would seasonally pass along

the upper portion of this new channel (cross section one), while the downstream portion would

be backwatered by the Mad River (cross section two).

All concepts assume that fill generated from excavations will be placed on site as embankment

along NF 5800 Road on site, contoured to blend into the surrounding landscape, and planted

with upland trees and shrubs. The fill could be also be configured to reduce visibility of the

project from the road and accessibility to recreational off road vehicles and snowmobiles.

Piezometer groundwater levels are currently being collected by water level data loggers and

will be downloaded in the spring of 2017. Groundwater elevation information is anticipated to

be useful for designing elevations that may be suited for wetlands and riparian plant

communities. However, the November 2016 pump tests at Pit 1 indicates that inflow rate is

very low, and other pits had insufficient inflow to warrant pump tests. Thus groundwater

inflow is not anticipated to be adequate as a supply for flow along the new channel.


March 2017 12

Concept 1: Fan Swale Extending to Mad River

Concept 1 excavates a 600‐foot‐long fan swale roughly parallel to Tillicum Creek and extending

to the right bank of the Mad River. Existing riparian vegetation will be protected to the degree

possible to maintain shade along the creek and river. Large wood would be placed in areas

expected to experience natural recruitment of wood. Ballasting designs will be completed at

future phases with an emphasis on backfill and driven vertical logs as the primary restraint.

The new fan swale alignment would meet the Mad River at a location that minimizes

disturbance to existing riparian vegetation. The Mad River will backwater into the new channel

to various extents and depths depending on river levels. Piezometer water level logger data

will be downloaded in the spring and evaluated in the next phase of work to evaluate

groundwater levels and the possibility of creating wetlands and opportunities to intercept

groundwater flow.

This is the smallest scale alternative in terms of earthwork volume, which is estimated to be

3,000 cubic yards (cy).


March 2017 13

Concept 2: Short Fan Swale Extending to Mad River Relic Channel

Concept 2 includes excavating a shorter length of fan swale through the existing field to

enhance flood prone areas similar to Concept 1. This concept also includes a 375‐foot‐long

excavation within the Mad River floodplain to emulate a relic channel of the Mad River that runs

along the distal edge of the Tillicum fan. The upstream end of this relic channel would include

a bar apex log structure to encourage portions of river flood flows to split into the relic channel,

providing floodplain function and habitat. The upstream half of the relic channel is anticipated

to be predominantly riparian wetland, with seasonal connection to groundwater and regularly

flooding, while the lower extents would be backwatered by the river to various extents and

depths depending on river stage.

This is the medium scale alternative, with less earthwork associated with the fan swale but

more earthwork associated with Mad River floodplain enhancement. Volume is estimated to be

4,400 cy.


March 2017 14

Concept 3: Long Fan Swale Extending to Mad River Relic Channel

Concept 3 is the largest scale project that combines aspects of Concepts 1 and 2, creating a long

fan swale that connects to a Mad River relic channel. This concept provides the greatest amount

of habitat and complexity at a variety of flows, and the largest acreage of wetland creation.

Earthwork volume is estimated to be 5,400 cy.

DESIGNER’S NOTES ON CONFIGURATIONS

The concepts presented here are meant to show a suite of possibilities. Each of these concepts is

scalable and can be combined or reconfigured into other schemes. The only limitation would be

on the amount of fill that can be placed on site. If a significantly larger scale scheme is

considered, offsite disposal of fill may be required.

The existing creek exhibits many attributes of good habitat, particularly during average and low

flows. The riparian corridor is narrow, but it provides excellent shade canopy over the stream,

and it is a source of small woody debris inputs and trapping. It was therefore decided to not


March 2017 15

include alternatives that re‐align the channel. Instead, the alternatives work with the existing

creek by attaching adjacent flood prone areas that would relieve flood stress in the channel

while also providing additional floodplain habitat and perennial backwater habitat.

Furthermore, by not altering the existing channel, impacts to the fish and wildlife that occupy

the stream are minimized, making environmental permitting easier, and significantly reducing

fish exclusion and rescue efforts during construction.

Although the intent is to leave the existing channel in its current alignment, alluvial fans are

naturally dynamic areas, so future sediment and debris loading, or beaver activity is expected

to cause the configuration to evolve over time.

5. References Mastin, M.C., Konrad, C.P., Veilleux, A.G., and Tecca, A.E., 2016, Magnitude, frequency, and

trends of floods at gaged and ungaged sites in Washington, based on data through water

year 2014 (ver 1.1, October 2016): U.S. Geological Survey Scientific Investigations Report

2016‐5118, 70 p.

United States Geological Survey. 2016. StreamStats Program. Web. March 27 2016.

<http://water.usgs.gov/osw/streamstats/>.

Upper Columbia Regional Technical Team (UCRTT). 2014. A Biological strategy to protect and

restore salmonid habitat in Upper Columbia Region (revised). A Report to the Upper

Columbia Salmon Recovery Board from the Upper Columbia Regional Technical Team.

http://www.ucsrb.org/Assets/Documents/Library/REVISED%20Upper%20Columbia%20Rev

ised%20Biological%20Strategy%202014%20(March%20).pdf

Upper Columbia Salmon Recovery Board (UCSRB). 2007. Upper Columbia salmon and

Steelhead recovery plan: Upper Columbia Salmon Recovery Board, Wenatchee,

Washington, 300 pp. <http://www.ucsrb.com/plan.asp>.

USDA‐NRCS (United States Department of Agriculture – Natural Resources Conservation

Service) National Cooperative Soil Survey. Official Soil Series Descriptions. Web. May 27,

2016.

<http://www.nrcs.usda.gov/wps/portal/nrcs/detailfull/soils/home/?cid=nrcs142p2_053587>.

Washington State Dept. of Transportation (WSDOT). 2010. US2, XL 2793/4 Tumwater Canyon

Bridge Replacements Geotechnical Report. Memorandum by B Romine. August 10, 2010.

Washington State Dept. of Transportation (WSDOT). 2014. WSDOT Fish Passage Performance

Report. Environmental Services Office, Biology Branch, Stream Restoration Program. 184

pp.


Attachments


‐ Grading plan and profile of alternatives ‐ Estimates

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9+30

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6+00

6+53

80

90

100

80

90

100

0+001+002+003+004+005+006+006+53

2.4%

3.2%

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94.

2GRAD

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103

.0

CONCEPT 1TILLICUM CREEK FAN CHANNEL

TO MAD RIVER

1 OF 3

MAD RIVER

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PROFILE

TILLICUM CREEK

3,000 CY EXCAVATION3,000 CY FILL

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0

CONCEPT 2TILLICUM CREEK FAN CHANNEL (SHORT)

AND MAD RIVER FLOODPLAIN ENHANCEMENT

2 OF 3

MAD RIVER

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CONCEPT 3TILLICUM CREEK FAN CHANNEL (LONG)

AND MAD RIVER FLOODPLAIN ENHANCEMENT

3 OF 3

MAD RIVER

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Appendix 1


Pebble count

Tillicum FanSediment Grain Size Analysis

Gravel bar Identifier SUBSTRATE PHOTO10/2/16 Date

MM, MBr PersonnelTillicum Ck Stream

0.75 Approximate Depth of Flow at Thalweg (ft)gravel bar Longitudinal Description (Pool, Riffle, Bend, Crossing)

surficial material Sample Type: Armor Layer or Subarmor

Notes:overview photo:

OVERVIEW PHOTO

Pebble Count DataClass (Wentworth) Size Class mm Frequency Cumulative %Sand <2 0 .0%Sand 2 3 3.4%Very Fine Gravel 2.1-4 0 3.4%Fine Gravel 4.1-5.7 0 3.4%Fine Gravel 5.8-8 0 3.4%Medium Gravel 8.1-11.3 1 4.6%Medium Gravel 11.4-16 5 10.3%Coarse Gravel 16.1-22.6 2 12.6%Coarse Gravel 22.7-32 6 19.5%Very Course Gravel 32.1-45 6 26.4%Very Course Gravel 45.1-64 13 41.4%Small Cobble 64.1-90 16 59.8%Small Cobble 90.1-128 21 83.9%Large Cobble 128.1-256 8 93.1%Small Boulders >256 6 100.0%

Total 87

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0

2

4

6

8

10

12

14

16

18

20

22

24

<2 2

2.1-

4

4.1-

5.7

5.8-

8

8.1-

11.3

11.4

-16

16.1

-22.

6

22.7

-32

32.1

-45

45.1

-64

64.1

-90

90.1

-128

128.

1-25

6

>256

Freq

uenc

y

Median Axis Diameter (mm)

Pebble CountSurficial Grain Size Analysis

Frequency

Cumulative %


Appendix 2


Hydrology

Flood Q Regression Tool. Use to estimate flood discharge in Washington State at ungaged sites based on regional regression equations and user-determined basin characteristics.

Steps Selected Region: Regression Region 21

= 22.2 square miles

= 35.00 inches

= 50 %

Selected Region: Regression Region 2

AEP *Qu, ft3/s PIL, in ft3/s PIU, in ft3/s

0.5 = 132 43.6 399.70.2 = 231 82.8 644.10.1 = 312 106.4 914.80.04 = 429 132.4 1390.50.02 = 533 150.0 1894.40.01 = 640 165.2 2478.80.005 = 757 176.6 3244.70.002 = 930 191.8 4510.3

*rounded to 3 significant figures

Prediction Intervals, 90% confidence level

2 Determine the drainage area, DA and the Annual Precipitation, P for the ungage drainage basin. If you pick Regression Region 1 or 2, determine the percent canopy cover, CAN .

Select the Regression Region below from the List Box

DA = Drainage Area, in square miles; P = Average Basin Annual Precipitation, in inches (from PRISM data set, years 1981-2010); CAN = Percent canopy cover (NLCD 2001); AEP = Annual Exceedance Probability; Qu = Flood Discharge, in cubic feet per second at ungaged site for the indicated AEP; PIL, PIU= Predition Intervals (L=Lower and U=Upper)

Instructions for using the Flood Q Tool to estimate Flood Discharges at Ungaged Sites using the regional regression equations

Instructions

User determined basin characteristics for ungaged site

Estimate of indicated flood discharge for Regression Region 2 using regional regression equations

Range of values that are valid for the regression

0.42 - 1820

8.86 - 84.20

Drainage Area, DA

Annual Precipitation, P

Percent Canopy, CAN 0.0 - 97.0

Regression Regions in Washington State

Rows 23-30 will have the results. Estimated flood discharge, Qu, will be found in column O and the 90% prediction limits for these flood discharges will be found in columns R and T. 4

3Enter these basin characteristic values in the green-shade cells. If the cell changes to red, than the value is outside the range of valid values for this regression. Valid value range listed to the right of the green cells.


Appendix 3


HEC‐RAS hydraulic modeling – existing conditions

Tillicum Ck

719.38

679.65

645.82

563.66

511.9

424.84387.24

287.31

247.32225.38

193.36

154.76

108.42

68.88

32.93T i l l i cum

Ck

0 100 200 300 400 500 600 70080

85

90

95

100

105

110

115

Tillicum Fan Plan: TF-Existing 1/24/2017

Main Channel Distance (ft)

Elev

atio

n (ft

)

Legend

WS 100yr

WS 50yr

WS 25yr

WS 10yr

WS 5yr

WS 2yr

WS ~1.25yr

WS ~1yr

WS 25cfs

WS 10cfs

Ground

LOB

ROB

57.6

768

.88

108.

42

154.

76

193.

36

225.

38

247.

32

287.

31

359.

85

387.

24

424.

84

485.

43

511.

9

563.

66

596.

8261

3.21

645.

82

679.

65

719.

38

Tillicum Ck Tillicum Ck

0 20 40 60 80 100 120104

106

108

110

112

114

116

118

120

Tillicum Fan Plan: TF-Existing 1/24/2017 RS = 719.38

Station (ft)

Elev

atio

n (ft

)

Legend

WS 100yr

WS 50yr

WS 25yr

WS 10yr

WS 5yr

WS 2yr

WS ~1.25yr

WS ~1yr

WS 25cfs

WS 10cfs

Ground

Bank Sta

.07 .04 .07

0 20 40 60 80 100 120104

106

108

110

112

114

116

118


Station (ft)

Elev

atio

n (ft

)

Legend

WS 100yr

WS 10yr

WS 50yr

WS 5yr

WS 25yr

WS 2yr

WS ~1.25yr

WS ~1yr

WS 25cfs

WS 10cfs

Ground

Bank Sta

.07 .04 .07

0 20 40 60 80 100 120 140 160104

106

108

110

112

114

116

118


Station (ft)

Elev

atio

n (ft

)

Legend

WS 100yr

WS 50yr

WS 25yr

WS 10yr

WS 5yr

WS 2yr

WS ~1.25yr

WS ~1yr

WS 25cfs

WS 10cfs

Ground

Bank Sta

.07 .04 .07

0 20 40 60 80 100 120 140 160102

104

106

108

110

112

114

116


Station (ft)

Elev

atio

n (ft

)

Legend

WS 100yr

WS 50yr

WS 25yr

WS 10yr

WS 5yr

WS 2yr

WS ~1.25yr

WS ~1yr

WS 25cfs

WS 10cfs

Ground

Bank Sta

.07 .04 .07

0 20 40 60 80 100 120 140 160100

102

104

106

108

110

112

114

116


Station (ft)

Elev

atio

n (ft

)

Legend

WS 100yr

WS 50yr

WS 25yr

WS 10yr

WS 5yr

WS 2yr

WS ~1.25yr

WS ~1yr

WS 25cfs

WS 10cfs

Ground

Bank Sta

.07 .04 .07

0 20 40 60 80 100 120 140 160 180100

102

104

106

108

110

112

114


Station (ft)

Elev

atio

n (ft

)

Legend

WS 100yr

WS 50yr

WS 25yr

WS 10yr

WS 5yr

WS 2yr

WS ~1.25yr

WS ~1yr

WS 25cfs

WS 10cfs

Ground

Bank Sta

.07 .04 .07

0 20 40 60 80 100 120 140 160 18098

100

102

104

106

108

110

112


Station (ft)

Elev

atio

n (ft

)

Legend

WS 100yr

WS 50yr

WS 25yr

WS 10yr

WS 5yr

WS 2yr

WS ~1.25yr

WS ~1yr

WS 25cfs

WS 10cfs

Ground

Bank Sta

.07 .04 .07

0 20 40 60 80 100 120 140 160 18098

100

102

104

106

108

110


Station (ft)

Elev

atio

n (ft

)

Legend

WS 100yr

WS 50yr

WS 25yr

WS 10yr

WS 5yr

WS 2yr

WS ~1.25yr

WS ~1yr

WS 25cfs

WS 10cfs

Ground

Bank Sta

.07 .04 .07

0 50 100 150 20096

98

100

102

104

106

108


Station (ft)

Elev

atio

n (ft

)

Legend

WS 100yr

WS 50yr

WS 25yr

WS 10yr

WS 5yr

WS ~1yr

WS 2yr

WS ~1.25yr

WS 25cfs

WS 10cfs

Ground

Bank Sta

.07 .04 .07

0 50 100 150 200 25096

98

100

102

104

106


Station (ft)

Elev

atio

n (ft

)

Legend

WS 100yr

WS 50yr

WS 25yr

WS 10yr

WS 5yr

WS 2yr

WS ~1.25yr

WS ~1yr

WS 25cfs

WS 10cfs

Ground

Bank Sta

.07 .04 .07

0 50 100 150 200 25092

94

96

98

100

102

104

106


Station (ft)

Elev

atio

n (ft

)

Legend

WS 100yr

WS 50yr

WS 25yr

WS 10yr

WS 5yr

WS 2yr

WS ~1.25yr

WS ~1yr

WS 25cfs

WS 10cfs

Ground

Bank Sta

.07 .04 .07

0 50 100 150 200 250 30090

92

94

96

98

100

102


Station (ft)

Elev

atio

n (ft

)

Legend

WS 100yr

WS 50yr

WS 25yr

WS 10yr

WS 5yr

WS 2yr

WS ~1.25yr

WS ~1yr

WS 25cfs

WS 10cfs

Ground

Bank Sta

.07 .04

.07

0 50 100 150 200 250 30088

90

92

94

96

98

100


Station (ft)

Elev

atio

n (ft

)

Legend

WS 100yr

WS 50yr

WS 25yr

WS 10yr

WS 5yr

WS 2yr

WS ~1.25yr

WS ~1yr

WS 25cfs

WS 10cfs

Ground

Bank Sta

.07 .04

0 50 100 150 200 250 30088

90

92

94

96

98


Station (ft)

Elev

atio

n (ft

)

Legend

WS 100yr

WS 50yr

WS 25yr

WS 10yr

WS 5yr

WS 2yr

WS ~1.25yr

WS ~1yr

WS 25cfs

WS 10cfs

Ground

Bank Sta

.07 .04

0 50 100 150 200 250 300 35086

88

90

92

94

96


Station (ft)

Elev

atio

n (ft

)

Legend

WS 100yr

WS 50yr

WS 25yr

WS 10yr

WS 5yr

WS 2yr

WS ~1.25yr

WS ~1yr

WS 25cfs

WS 10cfs

Ground

Bank Sta

.07 .04

.07

0 50 100 150 20086

87

88

89

90

91

92

93

94


Station (ft)

Elev

atio

n (ft

)

Legend

WS 100yr

WS 50yr

WS 25yr

WS 10yr

WS 5yr

WS 2yr

WS ~1.25yr

WS ~1yr

WS 25cfs

WS 10cfs

Ground

Bank Sta

.07 .04 .07

0 50 100 150 20085

86

87

88

89

90

91

92


Station (ft)

Elev

atio

n (ft

)

Legend

WS 100yr

WS 50yr

WS 25yr

WS 10yr

WS 5yr

WS 2yr

WS ~1.25yr

WS ~1yr

WS 25cfs

WS 10cfs

Ground

Bank Sta

.07 .04

.07

0 20 40 60 80 100 120 140 160 18084

85

86

87

88

89

90


Station (ft)

Elev

atio

n (ft

)

Legend

WS 100yr

WS 50yr

WS 25yr

WS 10yr

WS 2yr

WS 5yr

WS ~1.25yr

WS ~1yr

WS 25cfs

WS 10cfs

Ground

Bank Sta

.07 .04 .07

0 50 100 150 20083

84

85

86

87

88

89

90


Station (ft)

Elev

atio

n (ft

)

Legend

WS 100yr

WS 50yr

WS 25yr

WS 10yr

WS 5yr

WS 2yr

WS ~1.25yr

WS ~1yr

WS 25cfs

WS 10cfs

Ground

Bank Sta

.07 .04 .07

0 5 10 15 20 25 30 3583

84

85

86

87

88


Station (ft)

Elev

atio

n (ft

)

Legend

WS 100yr

WS 50yr

WS 25yr

WS 10yr

WS 5yr

WS 2yr

WS ~1.25yr

WS ~1yr

WS 25cfs

WS 10cfs

Ground

Bank Sta

.07 .04 .07

HEC-RAS Plan: Ex River: Tillicum Ck Reach: Tillicum CkReach River Sta Profile Q Total Min Ch El W.S. Elev Crit W.S. E.G. Elev E.G. Slope Vel Chnl Flow Area Top Width Froude # Chl Shear Chan

(cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) (sq ft) (ft) (lb/sq ft)Tillicum Ck 719.38 10cfs 10.00 105.71 106.36 106.36 106.52 0.035216 3.26 3.06 9.47 1.01 0.70Tillicum Ck 719.38 25cfs 25.00 105.71 106.63 106.63 106.89 0.030693 4.11 6.08 11.96 1.02 0.96Tillicum Ck 719.38 ~1yr 55.00 105.71 107.03 107.00 107.40 0.023600 4.85 11.33 14.09 0.95 1.16Tillicum Ck 719.38 ~1.25yr 80.00 105.71 107.28 107.24 107.73 0.022325 5.34 14.98 15.41 0.96 1.32Tillicum Ck 719.38 2yr 132.00 105.71 107.63 107.63 108.27 0.023089 6.39 20.68 16.92 1.01 1.74Tillicum Ck 719.38 5yr 231.00 105.71 108.21 108.21 109.10 0.019813 7.60 31.03 18.93 0.99 2.17Tillicum Ck 719.38 10yr 312.00 105.71 108.63 108.63 109.68 0.017892 8.29 39.24 20.39 0.98 2.41Tillicum Ck 719.38 25yr 429.00 105.71 109.28 109.28 110.37 0.013461 8.53 58.80 34.14 0.89 2.34Tillicum Ck 719.38 50yr 533.00 105.71 109.71 109.71 110.86 0.012167 8.90 73.75 35.00 0.86 2.43Tillicum Ck 719.38 100yr 640.00 105.71 110.02 110.02 111.31 0.012487 9.56 85.33 45.81 0.89 2.73

Tillicum Ck 679.65 10cfs 10.00 104.96 105.99 105.58 106.02 0.003716 1.48 6.74 12.09 0.35 0.12Tillicum Ck 679.65 25cfs 25.00 104.96 106.38 105.92 106.45 0.004423 1.99 12.54 16.41 0.40 0.20Tillicum Ck 679.65 ~1yr 55.00 104.96 106.80 106.92 0.005570 2.75 20.02 19.15 0.47 0.34Tillicum Ck 679.65 ~1.25yr 80.00 104.96 107.03 107.20 0.006626 3.26 24.54 20.63 0.53 0.46Tillicum Ck 679.65 2yr 132.00 104.96 107.39 106.90 107.66 0.007632 4.11 32.27 22.26 0.59 0.68Tillicum Ck 679.65 5yr 231.00 104.96 107.91 107.42 108.35 0.008963 5.33 44.45 24.56 0.66 1.04Tillicum Ck 679.65 10yr 312.00 104.96 108.20 107.79 108.80 0.010588 6.27 51.68 25.82 0.73 1.39Tillicum Ck 679.65 25yr 429.00 104.96 107.83 108.23 109.48 0.035476 10.34 42.41 24.19 1.31 3.98Tillicum Ck 679.65 50yr 533.00 104.96 108.12 108.62 110.02 0.034461 11.09 49.74 25.49 1.31 4.39Tillicum Ck 679.65 100yr 640.00 104.96 108.45 108.94 110.48 0.031290 11.53 58.37 27.61 1.28 4.54

Tillicum Ck 645.82 10cfs 10.00 104.74 105.54 105.54 105.73 0.034428 3.46 2.89 7.95 1.01 0.76Tillicum Ck 645.82 25cfs 25.00 104.74 105.87 105.87 106.11 0.031281 3.95 6.37 13.65 1.01 0.91Tillicum Ck 645.82 ~1yr 55.00 104.74 106.22 106.22 106.53 0.030933 4.42 12.65 22.96 1.04 1.07Tillicum Ck 645.82 ~1.25yr 80.00 104.74 106.39 106.39 106.77 0.027733 4.97 16.46 23.30 1.03 1.25Tillicum Ck 645.82 2yr 132.00 104.74 106.68 106.68 107.20 0.024349 5.83 23.37 23.92 1.02 1.53Tillicum Ck 645.82 5yr 231.00 104.74 107.18 107.18 107.89 0.019680 6.82 36.37 30.84 0.98 1.84Tillicum Ck 645.82 10yr 312.00 104.74 107.54 107.54 108.33 0.016935 7.29 48.92 38.89 0.94 1.96Tillicum Ck 645.82 25yr 429.00 104.74 107.91 107.91 108.86 0.016385 8.10 65.03 47.24 0.95 2.27Tillicum Ck 645.82 50yr 533.00 104.74 108.47 108.47 109.21 0.010194 7.40 109.03 91.78 0.78 1.76Tillicum Ck 645.82 100yr 640.00 104.74 108.54 108.71 109.50 0.013217 8.56 115.05 93.74 0.89 2.34

Tillicum Ck 613.21 10cfs 10.00 102.38 102.63 102.76 103.11 0.325161 5.56 1.80 13.31 2.67 2.73Tillicum Ck 613.21 25cfs 25.00 102.38 102.73 102.96 103.65 0.313628 7.69 3.25 14.39 2.85 4.40Tillicum Ck 613.21 ~1yr 55.00 102.38 102.91 103.25 104.23 0.233983 9.20 5.98 16.22 2.67 5.35Tillicum Ck 613.21 ~1.25yr 80.00 102.38 103.02 103.44 104.65 0.220889 10.25 7.81 17.25 2.68 6.20Tillicum Ck 613.21 2yr 132.00 102.38 103.22 103.78 105.33 0.178291 11.67 11.38 18.43 2.56 7.14Tillicum Ck 613.21 5yr 231.00 102.38 103.55 104.33 106.33 0.136205 13.42 17.77 20.43 2.40 8.24Tillicum Ck 613.21 10yr 312.00 102.38 103.79 104.68 106.94 0.115417 14.35 22.97 21.91 2.29 8.74Tillicum Ck 613.21 25yr 429.00 102.38 104.15 105.13 107.57 0.090697 15.07 31.09 24.06 2.12 8.85Tillicum Ck 613.21 50yr 533.00 102.38 104.40 105.49 108.18 0.083560 15.95 37.21 24.97 2.08 9.44

HEC-RAS Plan: Ex River: Tillicum Ck Reach: Tillicum Ck (Continued)Reach River Sta Profile Q Total Min Ch El W.S. Elev Crit W.S. E.G. Elev E.G. Slope Vel Chnl Flow Area Top Width Froude # Chl Shear Chan

(cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) (sq ft) (ft) (lb/sq ft)Tillicum Ck 613.21 100yr 640.00 102.38 104.74 105.83 108.42 0.065832 15.86 45.82 25.74 1.90 8.82




Tillicum Ck 485.43 10cfs 10.00 98.85 99.31 99.31 99.47 0.034599 3.21 3.13 9.98 1.00 0.69Tillicum Ck 485.43 25cfs 25.00 98.85 99.58 99.58 99.86 0.028827 4.24 6.00 11.20 1.00 0.99Tillicum Ck 485.43 ~1yr 55.00 98.85 99.97 99.97 100.40 0.024866 5.30 10.73 12.96 1.00 1.34Tillicum Ck 485.43 ~1.25yr 80.00 98.85 100.23 100.23 100.76 0.023241 5.87 14.24 14.13 1.00 1.53Tillicum Ck 485.43 2yr 132.00 98.85 100.66 100.66 101.36 0.020815 6.78 20.75 16.49 0.99 1.85Tillicum Ck 485.43 5yr 231.00 98.85 101.32 101.32 102.26 0.017288 7.95 33.07 20.68 0.96 2.24Tillicum Ck 485.43 10yr 312.00 98.85 101.79 101.79 102.85 0.015489 8.58 43.29 23.05 0.94 2.45


(cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) (sq ft) (ft) (lb/sq ft)Tillicum Ck 485.43 25yr 429.00 98.85 102.23 102.23 103.59 0.016353 9.81 53.71 23.74 0.99 3.03Tillicum Ck 485.43 50yr 533.00 98.85 103.15 103.15 104.18 0.009213 8.79 95.36 69.04 0.78 2.23Tillicum Ck 485.43 100yr 640.00 98.85 103.49 103.64 104.55 0.008961 9.16 122.02 86.84 0.78 2.35




Tillicum Ck 287.31 10cfs 10.00 90.23 90.85 90.85 91.02 0.035435 3.28 3.05 9.37 1.02 0.71Tillicum Ck 287.31 25cfs 25.00 90.23 91.14 91.14 91.40 0.030091 4.11 6.08 11.77 1.01 0.96Tillicum Ck 287.31 ~1yr 55.00 90.23 91.51 91.52 91.90 0.026791 5.01 10.98 14.40 1.01 1.25Tillicum Ck 287.31 ~1.25yr 80.00 90.23 91.75 91.75 92.22 0.025128 5.48 14.61 15.96 1.01 1.41Tillicum Ck 287.31 2yr 132.00 90.23 92.13 92.13 92.75 0.022678 6.30 21.04 17.72 1.00 1.69


(cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) (sq ft) (ft) (lb/sq ft)Tillicum Ck 287.31 5yr 231.00 90.23 92.63 92.69 93.57 0.022285 7.82 30.11 19.10 1.05 2.33Tillicum Ck 287.31 10yr 312.00 90.23 92.92 93.09 94.17 0.024015 9.01 35.74 19.91 1.12 2.94Tillicum Ck 287.31 25yr 429.00 90.23 93.25 93.61 94.96 0.026938 10.57 42.51 20.84 1.22 3.84Tillicum Ck 287.31 50yr 533.00 90.23 93.50 94.01 95.63 0.029313 11.81 47.84 21.54 1.29 4.63Tillicum Ck 287.31 100yr 640.00 90.23 93.72 94.40 96.29 0.031720 12.98 52.77 22.17 1.36 5.44




Tillicum Ck 154.76 10cfs 10.00 86.42 87.10 87.04 87.22 0.021265 2.73 3.67 10.17 0.80 0.47Tillicum Ck 154.76 25cfs 25.00 86.42 87.36 87.32 87.59 0.024667 3.89 6.43 11.60 0.92 0.84Tillicum Ck 154.76 ~1yr 55.00 86.42 87.70 87.70 88.11 0.026505 5.12 10.73 13.39 1.01 1.29


(cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) (sq ft) (ft) (lb/sq ft)Tillicum Ck 154.76 ~1.25yr 80.00 86.42 87.90 87.94 88.45 0.028186 5.96 13.45 14.33 1.07 1.64Tillicum Ck 154.76 2yr 132.00 86.42 88.32 88.35 89.02 0.023618 6.75 19.90 16.12 1.03 1.90Tillicum Ck 154.76 5yr 231.00 86.42 88.77 88.99 89.93 0.028501 8.72 27.54 18.00 1.17 2.92Tillicum Ck 154.76 10yr 312.00 86.42 89.06 89.48 90.57 0.030819 9.96 33.14 20.87 1.25 3.63Tillicum Ck 154.76 25yr 429.00 86.42 89.44 90.04 91.38 0.031889 11.37 42.54 28.35 1.31 4.47Tillicum Ck 154.76 50yr 533.00 86.42 89.72 90.46 91.98 0.032494 12.37 51.06 32.29 1.34 5.09Tillicum Ck 154.76 100yr 640.00 86.42 89.97 90.77 92.53 0.033330 13.30 59.47 35.75 1.38 5.71



Tillicum Ck 57.67 10cfs 10.00 83.39 84.69 84.38 84.77 0.010049 2.23 4.62 9.51 0.57 0.29Tillicum Ck 57.67 25cfs 25.00 83.39 85.04 85.20 0.010854 3.16 8.14 10.55 0.63 0.50Tillicum Ck 57.67 ~1yr 55.00 83.39 85.53 85.79 0.012785 4.12 13.78 13.67 0.72 0.77Tillicum Ck 57.67 ~1.25yr 80.00 83.39 85.81 86.14 0.012674 4.57 18.07 15.43 0.74 0.90Tillicum Ck 57.67 2yr 132.00 83.39 86.23 86.71 0.012774 5.59 24.50 15.88 0.78 1.23Tillicum Ck 57.67 5yr 231.00 83.39 86.69 86.57 87.57 0.016740 7.58 31.92 16.38 0.93 2.07Tillicum Ck 57.67 10yr 312.00 83.39 87.27 87.27 88.18 0.012686 7.80 48.09 39.48 0.85 2.01Tillicum Ck 57.67 25yr 429.00 83.39 87.32 87.85 88.95 0.022262 10.46 50.10 41.02 1.13 3.60Tillicum Ck 57.67 50yr 533.00 83.39 87.54 88.15 89.50 0.024703 11.62 60.08 47.94 1.20 4.33Tillicum Ck 57.67 100yr 640.00 83.39 88.90 88.48 89.55 0.006173 7.50 158.00 116.52 0.64 1.59

Tillicum Ck 32.93 10cfs 10.00 83.63 84.15 84.15 84.33 0.034784 3.43 2.92 8.14 1.01 0.76


(cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) (sq ft) (ft) (lb/sq ft)Tillicum Ck 32.93 25cfs 25.00 83.63 84.46 84.46 84.76 0.029984 4.39 5.70 9.76 1.01 1.06Tillicum Ck 32.93 ~1yr 55.00 83.63 84.89 84.89 85.33 0.025891 5.33 10.38 12.05 1.01 1.36Tillicum Ck 32.93 ~1.25yr 80.00 83.63 85.15 85.15 85.69 0.024014 5.90 13.69 13.45 1.00 1.56Tillicum Ck 32.93 2yr 132.00 83.63 85.62 85.62 86.30 0.018821 6.67 21.26 19.16 0.94 1.76Tillicum Ck 32.93 5yr 231.00 83.63 86.29 86.29 87.16 0.015670 7.73 35.79 26.09 0.92 2.10Tillicum Ck 32.93 10yr 312.00 83.63 86.50 86.75 87.75 0.020447 9.37 41.54 30.00 1.06 2.99Tillicum Ck 32.93 25yr 429.00 83.63 87.00 87.27 88.38 0.018427 10.08 57.42 33.05 1.04 3.25Tillicum Ck 32.93 50yr 533.00 83.63 87.35 87.61 88.85 0.017828 10.69 69.10 33.05 1.04 3.52Tillicum Ck 32.93 100yr 640.00 83.63 87.92 87.92 89.27 0.013492 10.36 88.00 33.05 0.93 3.13