Lower Davis Creek Rehabilitation – The Final Implementation Stages of the Red Hill Creek Watershed Plan below the , City of Hamilton

November 21, 2013 Presentation Outline

Lower Davis Creek Rehabilitation 1.Study Area 2.Background 3.Design and Construction

Lower Davis Creek Rehabilitation November 21, 2013 2 Lower Davis Creek Rehabilitation

Study Area

Lower Davis Creek Rehabilitation November 21, 2013 3 1. Study Area

. Davis Creek subwatershed outlets to the Red Hill Creek at the Red Hill Valley , within the City of Hamilton.

Lower Davis Creek Rehabilitation November 21, 2013 4 1. Study Area • Davis Creek subwatershed area of 1,170 ha • Above the Niagara Escarpment (Upper Davis) • Below the Niagara Escarpment (Lower Davis)

Lower Davis Creek Rehabilitation November 21, 2013 5 Background

Lower Davis Creek Rehabilitation November 21, 2013 6 2. Background

• The award – winning Red Hill Creek Watershed Plan (RHCWP), October 1998 provided goals, objectives for:

Land development

Storm infrastructure (including the Davis Creek Flood Control Facility) Conservation, restoration and rehabilitation efforts within the Red Hill Creek watershed.

Lower Davis Creek Rehabilitation November 21, 2013 7 2. Background

• Davis Creek Subwatershed Study (DCSS) completed in October 2006 Recommendations for Lower Davis Creek improvements • Lower Davis Creek (LDC) Class Environmental Assessment completed in May 2011 in response • Detail design and construction of the Lower Davis Creek rehabilitation designed 2012, approved and completed by May 2013

Lower Davis Creek Rehabilitation November 21, 2013 8 2. Background

Issues with Lower Davis Creek included:  Significant bed and bank erosion  Failing instream concrete structures  Entrenchment/ disconnect with flood plain  Numerous debris blockages  Fisheries barriers from Red Hill Creek

Lower Davis Creek Rehabilitation November 21, 2013 9 2. Background

Davis Creek Flood Control Facility

• City of Hamilton, as part of Red Hill Valley Parkway, completed an Impact Assessment and Design Process (IADP) in 2003.

Lower Davis Creek Rehabilitation November 21, 2013 10 2. Background

IADP recommended: •Davis Creek Flood Control Facility to reduce flood risk to Red Hill Valley Parkway by 20%. •Davis Creek Flood Control Facility constructed in 2013.

Lower Davis Creek Rehabilitation November 21, 2013 11 Lower Davis Creek Rehabilitation

Design and Construction

Lower Davis Creek Rehabilitation November 21, 2013 12 3. Design and Construction

Lower Davis Creek Rehabilitation

Design and construction considerations

Lower Davis Creek Rehabilitation November 21, 2013 13 3. Design and Construction

Lower Davis Creek Rehabilitation

Detail design and construction divided into three (3) phases: • Phase 1: Escarpment to Quigley Road • Phase 2: Quigley Road to CPR tracks • Phase 3: CPR tracks to Quigley Road

Length of creek works just over 2 km.

Lower Davis Creek Rehabilitation November 21, 2013 14 3. Design and Construction

Phase 1:

• Escarpment to Quigley Road (South of Greenhill Ave.)

Lower Davis Creek Rehabilitation November 21, 2013 15 3. Design and Construction

Phase 1:

• Severely eroded bank with top of bank uses at risk protected with vegetated stone bank treatment

Lower Davis Creek Rehabilitation November 21, 2013 16 3. Design and Construction

Phase 1:

• Thalweg deposition zone • Thalweg reshaped and profile adjusted to improve sediment transport • Grade control features installed to maintain bed material in place

Lower Davis Creek Rehabilitation November 21, 2013 17 3. Design and Construction

Phase 1:

• Greenhill Avenue to Quigley Road • Removal of a concrete structure and bar formation.

Lower Davis Creek Rehabilitation November 21, 2013 18 3. Design and Construction

Phase 1:

• Removal of concrete drop structure • Channel lined with armour stone and riffle constructed

Lower Davis Creek Rehabilitation November 21, 2013 19 3. Design and Construction

Phase 1:

• Removal of bar. Thalweg and banks reshaped, profile adjusted

Lower Davis Creek Rehabilitation November 21, 2013 20 3. Design and Construction

Phase 2:

• Quigley Road to (CPR) • Creek realigned to reduce entrenchment and protect property • Drop structures removed

Lower Davis Creek Rehabilitation November 21, 2013 21 3. Design and Construction

Phase 2:

• Realign creek and remove concrete aprons

Lower Davis Creek Rehabilitation November 21, 2013 22 3. Design and Construction

Phase 2:

• Improved thalweg and creek re-connection to floodplain

Lower Davis Creek Rehabilitation November 21, 2013 23 3. Design and Construction

Phase 2:

• Storm sewer outfall improvements

Lower Davis Creek Rehabilitation November 21, 2013 24 3. Design and Construction

Phase 3:

• CPR culvert/channel connection • Three (3) instream structures removed

Lower Davis Creek Rehabilitation November 21, 2013 25 3. Design and Construction

Phase 3:

• Improved fish passage through the CPR culvert • Constructed riffle cascade downstream of the culvert and increased tail water depth

Lower Davis Creek Rehabilitation November 21, 2013 26 3. Design and Construction

Phase 3:

• Failing armour stone lined channel • Replaced with riffle cascade downstream of the CPR culvert • Facilitates fish passage to downstream side of the CPR culvert

Lower Davis Creek Rehabilitation November 21, 2013 27 3. Design and Construction

Phase 3:

• Rehabilitation of outflanked concrete apron and severely entrenched creek

Lower Davis Creek Rehabilitation November 21, 2013 28 3. Design and Construction

Phase 3:

• Concrete apron partially removed over 1200 mm water main • Pool/ riffle sequence to provide adequate flow depth over remaining apron for fish passage • Side channel repaired • Banks rehabilitated using vegetated stone bank treatment

Lower Davis Creek Rehabilitation November 21, 2013 29 3. Design and Construction

Phase 3:

• Concrete apron outflanked and active bank erosion upstream of apron • Apron removed and channel reconstructed using pool/riffle sequence

Lower Davis Creek Rehabilitation November 21, 2013 30 3. Design and Construction

Davis Flood Control Facility

Represents one component of a multi-facility, watershed-wide flood management strategy designed to protect major highways serving up to 100,000 cars daily along with related infrastructure.

Lower Davis Creek Rehabilitation November 21, 2013 31 3. Design and Construction

Prevent Flooding of Red Hill Valley Parkway and QEW

Images from flood event of July 26, 2009 (estimated to be in excess of 100 year event)

Lower Davis Creek Rehabilitation November 21, 2013 32 3. Design and Construction

Challenges: 1. Maximize protection of Red Hill Valley Parkway & QEW while preventing road embankment overtopping during > 100 year storm events 2. Passage for wildlife and fish to be maintained/ improved from Red Hill Creek valley to Lower Davis Creek valley 3. Mitigate slope stability issues along valley affecting adjacent private properties 4. Improve natural environment throughout the facility

Lower Davis Creek Rehabilitation November 21, 2013 33 3. Design and Construction

Lower Davis Creek Rehabilitation November 21, 2013 34 3. Design and Construction

• Outlet control structure and creek rehabilitation

• Upstream valley: creek rehabilitation and slope stabilization works

• Stone trench separates channel from toe of slope stabilization berms

Lower Davis Creek Rehabilitation November 21, 2013 35 3. Design and Construction

Facts: 1. Up to 20% flood protection volume for Red Hill Valley Parkway 2. Retrofit of twin cell box culvert 3. 1200 ha +/- drainage area 4. 120 m3/s design flow (Regional Storm/Hurricane Hazel) 5. 500,000 m3 flood control storage 6. 11 ha footprint 7. 9 m operating depth (max) 8. Automated eletromechanical gate 9. Backup (redundant) manually operated flap-type gate (operated by winch and hand- held power actuator)

Lower Davis Creek Rehabilitation November 21, 2013 36 3. Design and Construction

• Channel realigned to centre thalweg with south culvert cell • North culvert cell invert raised 0.5 m. Conveys flow < 50 year design event • South culvert cell fitted with 0.6 m concrete sill to facilitate fish passage through culvert

Lower Davis Creek Rehabilitation November 21, 2013 37 3. Design and Construction

• Riffle downstream designed to accommodate culvert concrete sill • Thalweg profile adjusted over 50 m to minimize slope increase • 1.5 m diameter boulders placed in channel bed to provide fish resting areas

Lower Davis Creek Rehabilitation November 21, 2013 38 Lower Davis Creek Rehabilitation – The Final Implementation Stages of the Red Hill Creek Watershed Plan below the Niagara Escarpment, City of Hamilton Thank you

November 21, 2013