Lower Davis Creek Rehabilitation – the Final Implementation Stages of the Red Hill Creek Watershed Plan Below the Niagara Escarpment, City of Hamilton
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Lower Davis Creek Rehabilitation – The Final Implementation Stages of the Red Hill Creek Watershed Plan below the Niagara Escarpment, 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 Parkway, 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 Canadian Pacific Railway (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.