Thomas R. Payne & Associates

Update on Flood Storage Fish Study

Presented by

Paul Schlenger, Bob Montgomery, Jim Shannon

June 15, 2011

Overview of Presentation

• Introduction• Update on Fish Study Analysis

Components– Hydrology– Water Quality– Geomorphology– Fish Habitat Modeling (PHABSIM)– Fish Population Modeling (SHIRAZ)

• Next Steps• Recommended Steps

Purpose of Fish Study

• To characterize the magnitude of potential impacts that a flood storage facility on the upper mainstem Chehalis River could have on anadromous salmon populations

Study Approach

• To use applicable existing and new data to characterize habitat conditions in the basin that contribute to salmon viability and would potentially be impacted by a dam– Hydrology and Hydraulics (water flow)– Water Quality (temperature)– Geomorphology (sediment transport)

Study Approach

Understanding of Dam Structure and Operations

Structure or Operational Element

Flood Storage Multi-Purpose

Construction Complete 2020 2020

Structure Location 2 miles south of Pe Ell (RM 108.3)

2 miles south of Pe Ell (RM 108.3)

Structure Height 238 feet 288 feet

Reservoir Surface Area (full)

1,000 acres 1,450 acres

Fish Passage Facilities Yes Yes

Sediment Transport Past Dam

No No

Large Woody Debris Transport Past Dam

No No

Fish Study Status

• Fish Study Elements– Hydrology – Water Quality – Geomorphology – Fish Habitat Modeling (PHABSIM) in prep.– Fish Population Modeling (SHIRAZ) in prep.

Geomorphology

•Geomorphic Reaches•Changes to Geomorphic Reaches from proposed flood storage facility

Geomorphic ReachesGeo-

morphic Reach Location Confinement

Average Gradient Comments

1 Headwaters to RM 107.8

Confined 1.05% Headwaters upstream of Pe Ell

2 RM 107.8 to RM 93.5

Moderately confined

0.25% Varies between confined and unconfinedIncludes Rainbow Falls

3 RM 93.5 to RM 88

Unconfined 0.05% South Fork Chehalis enters at downstream end

4 RM 88 to RM 75.5

Locally confined

0.06% Newaukum River enters at downstream end

Channel incised at downstream end5 RM 75.5 to

RM 61.7Locally

confined0.03% No gravel or cobble transport; bedrock

control at downstream endIncised channel

mid-reach 6 RM 61.7 to

RM 33Unconfined 0.07% Very wide flood plain

Black River enters mid-reach

Changes to Geomorphology

•Reduced peak flow•Channel migration•Bedload transport

•Reduced sediment and wood input

Estimated Changes to Geomorphology

• Reach 1 (upstream-most reach)– Inundated

• Reach 2– Transport capacity 4 percent of existing. – Bedload transport 4 of 20 years vs. 12 of 20.– Sediment input 29 percent of existing.– Change? Aggradation and percent fines up.

• Reach 3– Similar to Reach 2 but also channel migration

patterns may change. Peak flow vs. aggradation?

Estimated Changes to Geomorphology

• Reach 4 and 5– Transport capacity 65 percent of existing. – Sediment input 75 percent of existing.– Change? Aggradation and percent fines

change relatively small.• Reach 6 (downstream-most reach)

– Changes muted because downstream of bedrock control grade.

Fish Habitat Modeling Using PHABSIM

• PHABSIM = Physical Habitat Simulation• PHABSIM is a subcomponent of IFIM

(Instream Flow Incremental Methodology)• PHABSIM and IFIM were developed as

aids to instream flow decision-making• PHABSIM predicts changes in habitat

availability with changes in flow

PHABSIM•Mesohabitat survey•Six reaches•Ten study sites•71 transects•Reviewed and agreed upon with WDFW and Ecology•Measured depth, velocity, substrate, and cover along transects

Mesohabitat ResultsChehalis River Reaches

Habitat TypePe Ell to Elk Creek

(RM 106.5 to 100.2)Elk Creek to South Fork

(RM 100.2 to 88.0)

South Fork to Newaukum

(RM 88.0 to 75.3)

Pool 34.3 61.6 70.6

Glide 22.3 11.2 11.2

Run 28.3 18.8 15.1

Low Gradient Riffle 14.9 7.5 3.0

High Gradient Riffle 0.2 0.2 -----

Cascade ----- 0.2 -----

Other ----- 0.5 0.1

Habitat Type

Newaukumto Skookumchuck(RM 75.3 to 66.8)

Skookumchuck toBlack River

(RM 66.8 to 47.0)Black River to Porter

(RM 47.0 to 33.3)

Pool 99.2 70.3 70.0

Glide 0.2 13.3 9.4

Run 0.6 11.4 14.6

Low Gradient Riffle ----- 5.0 6.0

High Gradient Riffle ----- ----- -----

Cascade ----- ----- -----

Other ----- ----- -----

PHABSIM-Flow and Life Stage Maximum

Study Reach

Flow (cfs) at Maximum Usable Habitat(80% Range)

Chinook Spawning Chinook Juvenile

Steelhead Spawning

Steelhead Juvenile

Coho Spawning

Dam Siteto Pe Ell

160(90 to 240)

130(60 to 350)

190(130 to 290)

170(70 to 350)

220(130 to 350)

Pe Ellto Elk Creek

260(120 to 400)

200(120 to 400)

350(180 to 500)

240(140 to 450)

350(220 to 600)

Elk Creekto South Fork

650(400 to 900)

300(150 to 700)

400(200 to 600)

400(200 to 800)

400(250 to 650)

South Fork to Newaukum River

950(350 to 1,400)

500(250 to 850)

350(200 to 600)

600(300 to 1,000)

350(150 to 750)

Skookumchuck to Black River

2,200(1,200 to 4,000)

1,000(350 to 2,200)

650(300 to 1,600)

1,400(500 to 2,600)

650(250 to 1,600)

Black River to Porter

2,200(1,200 to 4,000)

1,000(350 to 2,200)

650(300 to 1,600)

1,400(500 to 2,600)

650(250 to 1,600)

PHABSIM

PHABSIM•Used results in SHIRAZ to determine spawning and rearing areas.•Results must be put into context.

•Other variables (i.e. water quality)•Looking at peaks oversimplifies results (i.e. maximum flow may not exist in a reach)•Usable habitat can be the same at two flows.

Fish Population Modeling Using SHIRAZ

• Microsoft Excel-based model to relate habitat conditions to salmon production– Capacity– Productivity

• User-defined inputs to build the model, i.e., a transparent model

• Allows for year-to-year changes in habitat conditions (as well as marine survival, harvest, and hatcheries, if desired)

Shiraz

Productivity Capacity

Survival

Habitat

Relies Upon Beverton-Holt Stock Recruitment Model

SHIRAZ Inputs

• Species data• Define assessment reaches• Populate model with data to characterize

habitat conditions in each reach• Establish relationships, i.e., functional

linkages, between habitat conditions and salmon survival

• Future condition scenarios

Species Data

• Species presence and distribution– Coho, spring Chinook, winter steelhead

• Life history– Freshwater lifestages– Age of outmigration– Age of return migration

• Species periodicity• Population numbers in the mainstem

Assessment Reaches

Habitat Conditions

• Capacity– Spawning area (flow dependent)– Rearing area (flow dependent)

• Productivity– Flow– Water temperature– Fine sediment in redds

Functional Linkages

0 2 4 6 8 10 12 14 16 18 200%

20%

40%

60%

80%

100%

Water Temperature During Egg Incubation(Deg C)

Eg

g S

urv

ival

Future Condition Scenarios

• Flood Storage Facility– Natural flows past dam when in non-flood

conditions– Following flood, downstream flows increased

by reservoir draining• Multi-Purpose Facility

– Controlled flows when in non-flood conditions, including potential to augment low flows

• Use studies to inform habitat condition changes

SHIRAZ Outputs

• Number of population alive by lifestage & area

• Life-cycle productivity

1990 2000 2010 2020 20300

500

1,000

1,500

2,000

Ob-served

Year

Nu

mb

er

of

Sp

rin

g

Ch

inook S

paw

ners

Next Steps

• Complete PHABSIM data collection and analysis

• Continue to build SHIRAZ models• Reporting• Data Transfer Workshop

Recommended Steps

• Collect more data on habitat conditions in proposed inundation area and representative portions of tributaries that would not be inundated

• Incorporate projected changes in basin hydrology associated with climate change

• Aerial photo interpretation of the growth of gravel bars

• Cross-section surveys at the same location as previous surveys, such as the FEMA surveys from the early 1980s – dual purpose to help in the sediment budget analysis and support updating the HEC-RAS model

Recommended Steps (continued)

• Investigate fish passage options for a dam• Investigate sediment transport and/or large

woody debris transport options for passing material past a dam

• Comprehensively identify opportunities to enhance habitat to improve fish population resilience in basin whether dam constructed or major floods encountered