Kinnickinnic River Flood Management and

Watercourse RehabilitationAchieving Multiple Design Objectives

Thomas R. Sear, PE, CFMShort Elliott Hendrickson

Patrick C. Elliott, MMSD

Kinnickinnic River (KKR) Watershed

KKR S. 6th St. to I-94 Bridge

Project Location

Updated Floodplain(SEWRPC, 2008)

6th St Bridge

KKR FM S. 6th St. to I-94 BridgeProject Area Characteristics

• South 6th Street Bridge • Upstream Watercourse Segment

– 500 feet of concrete lined channel– Confined cross-Sections– Steep northern embankment– MMSD CSO Facility on south

• Downstream Watercourse Segment– 500 feet of earthen / rock lined channel– Eroded north embankment, south of 5th Street– Heavily vegetated north embankment– South embankment instability

KKR FM Project Limits

Downstream WC Segment

Sout

h 6t

hSt

reet

Kinnickinnic River

Sout

h 5t

h St

reet

Brid

ge

KKR FM Project Limits

Downstream WC Segment

Sout

h 6t

hSt

reet

Kinnickinnic River

Sout

h 5t

h St

reet

Brid

ge

KKR 6th St. Bridge – Upstream (West Side)

KKR 6th St. Bridge – Downstream (East Side)

KKR Upstream Watercourse Segment

• Concrete Lined Channel– Constructed in 1983– 500 ft. length, 2:1 side slopes– 60 ft top width, 24 ft bottom width

• Northern Embankment– Buried (300 ft. long) WPA Wall– Railroad trestle remnants– Steep and unstable side slopes

• Southern Embankment– Maintenance Ramp– MMSD CSO facility and outfall

KKR Upstream Watercourse Segment

MMSD KK1 FacilityCombined

Sewer Outfall

Maintenance Ramp

South 6th Street

Unstable Embankment with Sand and

Gravel Fill Material

End of Concrete

Lined Channel

KKR Upstream Watercourse Segment

MMSD CSO Control Facility

Combined Sewer OutfallMaintenance

Ramp

Unstable Embankment with Sand and

Gravel Fill Material

KKR Upstream Watercourse Segment

KKR Upstream Watercourse Segment

KKR Downstream of South 6th Street BridgeJune 7, 1961

WPA Revetment Wall Buried in 1983

Existing KKR Concrete Lined ChannelConstructed 1983

Buried WPA Revetment

Wall

WPA Wall Weep Hole

Combined Sewer Outfall

84” Diameter RCP Storm

Sewer Outfall

Existing KKR Concrete Lined Channel and Buried WPA Revetment Wall, 1983

Buried WPA Revetment

Wall

Approx. 15 ft

WPA Wall Weep Hole

24 feet18 feet 18 feet

KKR Downstream Watercourse Segment• Earthen / Rock Lined Channel

– 500 ft. length– Channel scour and deposition – Embankment erosion– Storm sewer outfalls

• Northern Embankment– Failing Gabion Structure– Embankment erosion south of 5th Street– Vegetated riparian areas

• Southern Embankment– Steep / unstable side slopes– Collapsing stone revetment walls– Exposed watercourse flushing pipeline

KKR Downstream Watercourse Segment

KKR Earthen / Rock Lined Channel

Steep and Unstable Side

Slopes

Eroded Side Slope due to 5th Street Runoff

Failing Revetment Wall

End of Concrete Lined Channel

Storm Sewer Outfalls

Storm Sewer Outfall

Exposed Abandoned Flushing Pipeline

KKR Downstream Watercourse Segment

Steep and Unstable Side

Slopes

Eroded Side Slope due to 5th Street Runoff

Failing Revetment Wall

Storm Sewer Outfalls

Storm Sewer Outfall

Exposed Abandoned Flushing Pipeline

KKR Earthen / Rock Lined Channel

KKR Downstream Watercourse Segment

KKR Downstream Watercourse Segment

Stakeholder Involvement

• KK River Neighborhood Plan– Plan for overall KK River Flood Management

Project– Coordination with local government agencies

and community groups– Successfully accommodated various design

requests from stakeholders • Public Meetings

Proposed Improvements KKR S. 6th Street Bridge

• Design Objectives– Significantly reduce upstream WSE’s– Maintenance / bike path beneath bridge

• Proposed Design Features– Clear span concrete girder bridge– Functional, durable and attractive bridge

• Final Design Complete– Currently Under Construction– Scheduled for Completion in Dec. 2010

Proposed Bridge

11-02-10 Bridge Construction

Proposed Improvements KKR Upstream Watercourse Segment

• Design Objectives– Rehabilitated Main Channel– Maintain stable side slopes / hydraulic capacity– Maintenance / bike path alignment

• Design Features– Realigned channel centerline– Stone lined channel with riffles and pools– Tiered retaining walls, both sides– Recycle WPA wall limestone blocks– 15 ft. wide maintenance / bike path

Upstream KKR Improvements

Minimum 2:1 Side Slopes

Future KKR Bike Trail

Retaining Walls

Upstream KKR Cross-Sections

Proposed Improvements KKR Downstream Watercourse Segment• Design Goals

– Rehabilitated main channel and floodplain– Stable embankment slopes– Native vegetation plantings– Promote watercourse sediment continuity

• Design Features– Stone lined channel with riffles and pools– 2:1 to 4:1 native vegetated side slopes– Reuse of limestone blocks / streambed stone– 15 ft. wide maintenance / bike path

Downstream KKR Improvements

Future KKR Bike Path

3:1 Side Slope, where space

allows

Five Pools within Main Channel

Repair erosion from 5th St.

runoff

KKR Downstream Cross-Section

Typical Riffle Section

KKR Main Channel Cross-Sections

Typical Pool Section

KKR Watercourse Rehabilitation Improvements Schedule

• Advertisement – May 2010• Construction Start – Oct. 2010• Construction Completion – Dec. 2011• Upstream Improvements

– Finishing Preliminary Engineering– Starting Home Acquisition/Deconstruction

Kinnickinnic River Project Team Acknowledgements

• Dale Miller, Mainstream Restoration

• Rose Chmielewski, Ecological Services of Milwaukee

• Doug Bath, Gestra Engineering