blue slough presentation

Reconnecting a River:Through the Woods and Under a Trail

Presented byPat Stevenson, Stillaguamish Tribe of IndiansTracy Drury, P.E., Anchor QEA LLC

Salmon Habitat Conference, Great Wolf LodgeApril 26th, 2011

STILLAGUAMISH STILLAGUAMISH TRIBE OF TRIBE OF INDIANSINDIANS


Chinook Salmon DistributionChinook Salmon Distribution


Status of Chinook PopulationsStatus of Chinook Populations

• Current Stillaguamish Chinook salmon populations are about 8% of historic levels

• Factors of decline include:– Land conversion– Forestry– Agriculture– Fishing– Population growth– Urban development


Habitat Limiting FactorsHabitat Limiting Factors

• Estuary/nearshore• Riparian areas• Large woody debris• Floodplain• Sediment• Hydrology


Stillaguamish Chinook 10-Year Stillaguamish Chinook 10-Year Habitat Recovery Project CostsHabitat Recovery Project Costs

SIRC Watershed Goal Projects Units Cost/Unit Total Costs

Landslide Treatments Treat 2 $ 4,500,000 Sediment

Forest Road Treatment (miles) 106 $ 30,000 $ 3,180,000 Instream Wood Engineered Log Jams 51 $ 67,000 $ 3,417,000

Riparian Acres Planted 400 $ 7,500 $ 3,000,000

Acres Restored 195 $ 20,000 $ 3,900,000 Estuary

Acres Created 120 $ 6,700 $ 804,000 Side Channel Acres Restored 30.0 $100,000 $ 3,000,000

$ 21,801,000

Possible Acquisition 1445 $ 6,000 $ 8,670,000

+40% Contingency & Inflation Total $ 42,659,400


Blue Slough Reconnection ProjectBlue Slough Reconnection Project

• Project was originally proposed in the 1970’s

• Concern arose about:– Culverts under the trail– Allowing the river to flow into the existing

channel– Potential impacts to property


Project ManagementProject Management

• Sponsor – Stillaguamish Tribe• Manager – Pat Stevenson with assistance

from Tribal biologists and field technicians

• Partners – Engineering: Anchor QEA– Landowners: Bob Soelberg, Stillaguamish

County Club, Snohomish County Parks and Recreation


Project BudgetProject Budget

• Phase 1 – Removal of fine sediment and organic matter from channel– NFWF $30,000– Landowner match $30,000

• Phase 2 – Excavation of Blue Slough channel– $420,000 – Match $80,000

• Phase 3 – Connection of channel to river– $200,000– Match $38,000


Site Map – Aerial ViewSite Map – Aerial View

2,600 ft of new channel

1,200 ft of improved channel


Site Map – Topographic ViewSite Map – Topographic View

1,200 ft of improved channel

2,600 ft of new channel


Project Site PlanProject Site Plan1,200 ft of improved channel

Lower pond~3.65 acres

Upper pond~1.27 acres

1,030 ft channel

6-ft culvert

9-ft culvert


Design ConceptDesign Concept

• Series of model runs and calculations• Iterative process• Chinese menu to select from for design


SurprisesSurprises

• Channel excavation resulted in significant increase in groundwater contributions

• First flood event (54,000 cfs) >20% greater than previous flood of record

• Upstream culvert plugged with fine materials, small branches, grasses, leaves


Lessons LearnedLessons Learned

• Disturbance of mainstem bed materials altered the natural armoring in the bed

• Flood lowered the channel grade adjacent to the upstream culvert – reduced connectivity

• Channel excavation provided significant increase in groundwater providing year round downstream connection


Immediate BenefitsImmediate Benefits

• Coho and chum spawning in the side channel

Salmonids caught in Blue Slough fyke trap 3/15 - 3/16/11

1

10

100

1000

Chinook Coho 0+ Coho 1+ Chum Steelhead Non-Salmonids

Species

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QuestionsQuestions

blue slough presentation

Technology

channel acres restoredunits

channel nfwf

connection of channel

ft of improved channel2

surprises channel excavation

stillaguamish county

ft culvert upper pond

channel grade adjacent