The Boardman: A River Reborn - Michigan · The Boardman: A River Reborn . Removing Dams for a Free...

The Boardman: A River Reborn Removing Dams for a Free Flowing River

Advances in Design and River Restoration Techniques: Part 1

Primary Project Components • Literature and Field Investigation • Hydrologic, Hydraulic and Geomorphic

Studies • Cass Road Bridge Design • Dam Removal / Breaching • River Restoration • Permitting

The Boardman River To Date

PHASE 2 Removal of Boardman Dam and Sabin Dam

Field Investigations • Topographic / Bathymetric Survey • Geotechnical Borings • Sediment Data • Flow Data • Wetland

Delineations

Primary Project Components • Literature and Field Investigation • Hydrologic, Hydraulic and

Geomorphic Studies • Cass Road Bridge Design • Dam Removal / Breaching • River Restoration • Permitting

Hydrologic Impact Assessment of Boardman River Dams

Ultimately found no evidence that any of the Boardman Dams provided the capacity to significantly attenuate flood flows.

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0 20 40 60 80 100 120

Stag

e (ft

)

Time (hours)

Boardman Dam Stage-Flow Hydrograph for 24hr 10yr Storm

Stage HW

Stage TW

Dam Flow

Inflow

0100020003000400050006000700080009000

10000

0 500 1000 1500

Disc

harg

e (c

fs)

Drainage Area (square miles)

Peak FQ Flood Prediction Results for Regional Analysis

2 -yr

10-yr

100-yr

Sediment Transport Analysis • Evaluate impacts upstream and downstream

Boardman Dam

Sabin Dam

S. Airport Rd. Crossing

Boardman Lake

Downtown Traverse City

Boardman Pond

Beitner Road

Sediment Transport Analysis • Sabin to Boardman Lake depositional reach

Beitner Rd. Boardman Dam

Sabin Dam

Boardman Lake

South Airport Rd.

Depositional Zone

Sediment Transport Analysis • Short term and

long term concerns • Sediment transport

modeling and sediment load investigations indicate impacts to infrastructure would likely be realized in 50+ years.

Short Term

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0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000

Elev

atio

n (ft

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Distance from dam (m)

MainstemMainstem LeftMainstem RightMPM modified, Equil LoadMPM, Equil Load, Wong & ParkerMPM, Rating CurveWilcock Rating Curve

Long Term

Cass Road Bridge Design • TS&L study incorporated

public and stakeholder feedback

• Two 12 foot vehicle lanes

• Two 8 foot shoulders

• Span restored Boardman River channel and floodplain

• Accommodate Boardman River Trail

• Meet Bridge Design Standards

• Construction Begins January 2016

Proposed Bridge

Dam Removal / Breaching

• Know hazards/risk • Develop appropriate breaching approach • Rally the troops – QAQC and Risk

Assessment

Dam Removal / Breaching • Evaluate your hazards and risks

– Dam Height – Dam Materials – Conditions


Boardman Dam

Sabin Dam

S. Airport Rd. Crossing

Boardman Lake

Downtown Traverse City


Beitner Rd. Boardman Dam

Sabin Dam

Boardman Lake

South Airport Rd.



Assessment

Dam Removal / Breaching • Developing the breaching plan

Dredged Intake Channel

Powerhouse

Historic Channel

Proposed Bridge

Earthen Dam (Proposed Breach Location)


Construction Access

Auxiliary Spillway

Bypass Siphon System



Assessment

Breaching Risk Assesment Name Affiliation Role

Dan DeVaun, PE URS Corporation Risk Assessment Facilitator Troy Naperala, PE URS Corporation Project Engineer

Vik Gautam URS Corporation Geotechnical Engineer Mike Damian, PG URS Corporation Sr. Dam Specialist David Sawitzki, PE URS Corporation Sr. Dam Engineer

Janeen Stalder URS Corporation Risk Assessment Facilitator Andy Selle Inter-Fluve, Inc. River Restoration Specialist

Frank Dituri Grand Traverse Band of Ottawa & Chippewa Indians Project Partner Kim Balke Conservation Resource Alliance Project Partner

Brett Fessell Grand Traverse Band of Ottawa & Chippewa Indians Project Partner Gregg Bird Grand Traverse County Health Department Emergency Management Coordinator

Bill Weihbrecht URS Corporation River Restoration Specialist Boardman Dam Breaching

Potential Risks Associated with Breaching Operation MITIGATION/RISK REDUCTION METHODS

Potential Risks Name Summary Description Design Features Monitoring/Instrumentation Other

1 Debris Debris at the Dam intake or

bypass intake

1. Onsite equipment for cleaning. 1. Daily observation. 1. Have debris removal pay item. 2. Include as a pay item. 2. 2. 3. Bypass intake screening. 3. 3.

2 Flood What is a safe flood event

for initial cut?

1. 100-yr flood for initial cut. 1. Onsite water level monitoring equipment.

1.

2. Identify area in core wall where flood flows would breach first.

2. Immediate notification of rising impoundment waters to URS and contractor.

2.

3. 3. Monitor local & regional weather conditions & forecasts.

3.

3 Initial Sequence Construction sequence of

auxiliary spillway

1. Construct spillway prior to full top cut.

1. 1. Stockpile broken concrete and/or rip rap.

2. Controlled overflow in single location.

2. 2. Pay items to stockpile and place.

3. Always construct downstream side first.

3. 3.

4. Include each spillway construction and articulated block installation as a pay item.

4. 4.

4 Spillway Crest

Capacity

Impact to flow capacity due to roughness of core wall

demolition

1. Specify overflow section to be cleanly cut by contractor.

1. 1. Have pay item per LF to saw-cut the concrete core wall, including its reinforcing steel.

The Boardman: A River Reborn - Michigan · The Boardman: A River Reborn . Removing Dams for a Free...

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