City Wide Study of Flood Vulnerability, Prioritization and Mitigation. City of Burlington Infrastructure Committee. July 6, 2015

Transcription

1 City Wide Study of Flood Vulnerability, Prioritization and Mitigation City of Burlington Infrastructure Committee July 6, 2015 CW File No

2 Presentation Outline 1. Overview of August 4, 2014 Storm and Response 2. Rainfall and Flood Characterization (August 4, 2014) 3. Identification and Prioritization of Flood Vulnerable Areas City-Wide 4. Preliminary Flood Mitigation Opportunities 5. Site Specific Flood Mitigation Projects 6. Summary of Recommendations 7. Actions Moving Forward 2

3 1. Overview of August 4, 2014 Storm and Response 3

4 1. Overview of August 4 th Storm and Response i. Storm Track / Comparison ii. Committees iii. Coordination with Region of Halton and Conservation Halton iv. Debris Clean-Up v. RPM Creek Maintenance vi. Flood Vulnerability, Prioritization and Mitigation Study 4

5 1. Overview of August 4 th Storm and Response 5

6 1. Overview of August 4 th Storm and Response RAIN EVENT COMPARISON Aug 4, 2014 Regional Rainfall Amount (mm) MAY 2000 July 2006 March 2011 October 2011 August 2013 May Year Storm (6 hr) 100 Year Storm (6 hr) 6 0

7 1. Overview of August 4 th Storm and Response Flood Steering Committee and Subcommittee: Established to continue action plan for the City s flood response: Creek Erosion and Maintenance Flood Vulnerability, Prioritization and Mitigation Study Private Property Drainage and Lot Grading Data Management and Geographic Information Systems (GIS) Ontario Disaster Relief Assistance Program (ODRAP) 7

8 1. Overview of August 4 th Storm and Response Coordinating with Halton Region and Conservation Halton City staff has been closely coordinating its flood response work with Halton Region and Conservation Halton. Information has been openly shared between all parties regarding flooding inspections, data management, GIS mapping, consultant flood studies and staff reports. 8

9 1. Overview of August 4 th Storm and Response Locations of Creek Debris Clean-Up by RPM Over 120 Locations 9

10 1. Overview of August 4th Storm and Response Tuck Street south of New Street Trees, shrubs & vegetation August 5,

11 1. Overview of August 4 th Storm and Response Tuck Creek at Fairview Street Debris at major culverts August 5,

12 1. Overview of August 4 th Storm and Response Shoreacres Creek south of New Street Trees, shrubs & vegetation August 5,

13 1. Overview of August 4 th Storm and Response Shoreacres Creek south of South Service Road Broken shale transported downstream 2015 August 5,

14 1. Overview of August 4 th Storm and Response RPM Creek Maintenance $100,000 additional base budget funding Enhanced level of service Bi-annual creek debris inspection program New equipment to assist debris clean-up in areas with access challenges Rural ditch maintenance program 14

15 1. Overview of August 4 th Storm and Response Flood Vulnerability, Prioritization & Mitigation Study Amec Foster Wheeler retained by the City 15

16 2. Rainfall and Flood Characterization (August 4, 2014) 16

17 2. Rainfall and Flood Characterization (August 4, 2014) The purpose of this part of the presentation is to: Briefly highlight the characteristics of the storm and the resulting flood including its variability across Burlington s watersheds Review / compare storm severity in relationship to current standards (i.e. characterize the storm and flood) 17

18 2. Rainfall and Flood Characterization (August 4, 2014) What caused the storm? Meteorological condition referred to as Training a series of storm cells that pass over a single area Causes: Cold front meets hot humid air mass Thunderstorm sets up Strong winds created by leading thunderstorm create another storm in its wake These repeat like a train on a track 18

19 2. Rainfall and Flood Characterization (August 4, 2014) Rainfall Measurement Rain is measured using two technologies: radar and local (point) gauges Radar data for Burlington are available from the US National Weather Service (Buffalo) and Environment Canada (King City & Exeter) Conservation Halton determined that Buffalo data were most accurate by comparing it to 34 local gauges (this was independently confirmed by AFW) 19

20 2. Rainfall and Flood Characterization (August 4, 2014) Rainfall Planning/Design Historic rainfall records from rain gauges are analyzed to statistically estimate the rainfall depth associated with a range of return periods (ie. 5, 25, 100 year storms) Example: the 100 year event describes a storm of a certain rainfall depth and duration that would occur, on average, every 100 years or a 1% chance of occurrence in any given year This rainfall information is specific to a rain gauge (point location) For Burlington, this is Environment Canada s Royal Botanical Gardens gauge 20

21 2. Rainfall and Flood Characterization (August 4, 2014) Rainfall Planning/Design Important for engineering purposes Design of culverts, bridges and channels For establishing the Regulatory floodplain, the Province uses the greater of the 100 year or the Regional Storm (a local observed event) Used to direct development out of flood hazard areas (est s) In southern Ontario, the Regional Storm is Hurricane Hazel (1954) When a large storm like August 4, 2014 occurs, it is important to compare it to the prevailing design storms (i.e. 100 year, Regional Storm and others) 21

22 2. Rainfall and Flood Characterization (August 4, 2014) Total rainfall accumulation by watershed (Source: NWS) Appleby Sheldon Shoreacres Tuck Creek Roseland 22

23 2. Rainfall and Flood Characterization (August 4, 2014) Rainfall Statistics Comparing August 4, 2014 to design storms Rainfall period August 4, :00 PM to 9:00 PM (Approximately 7 hours) Maximum rainfall depth = 196 mm (Roseland/Tuck Creek) Maximum rainfall intensity = 22.7 mm in 10 minutes (Shoreacres/Appleby Creek) Average rainfall depth by watershed Tuck Creek 150 mm Shoreacres Creek 140 mm Appleby Creek 130 mm Roseland Creek 120 mm Sheldon Creek 100 mm Design Standards 5 Year (6 hours) is 49.4 mm 100 Year (6 hours) is 87.7 mm Hurricane Hazel (12 hours) is 212 mm 23

24 2. Rainfall and Flood Characterization (August 4, 2014) Flood Characterization Types of flooding mechanisms: 1. Basement flooding due to sanitary system back-up 2. Basement flooding due to foundation drain (weeper) back-up where connected to sanitary 3. Riverine (creeks overflowing their banks) 4. Roads (overtopping culverts and bridges) 5. Urban (overland/depressional) 6. Lot Level / Grading (private) 7. Basement Flooding due to Foundation drain where connected to storm Region of Halton is addressing Mechanisms 1 and 2 City of Burlington is addressing Mechanisms 3, 4, 5, 6 and 7 Note: Flooding can also be a combination of mechanisms including various interdependencies. 24

25 Basement Flooding Sewer Backup Source: Institute for Catastrophic Loss Reduction 25

26 Basement Flooding -Overland Source: Institute for Catastrophic Loss Reduction 26

27 2. Rainfall and Flood Characterization (August 4, 2014) Creek overtopping Creek overtopping Culvert overtopping Flooded roadway 27

28 2. Rainfall and Flood Characterization (August 4, 2014) Flood Characterization (Riverine) Results have been compared to design storms Location Drainage Area (ha) Tuck Creek Peak Flow (m 3 /s) 100 Year 04-Aug-14 Regional Storm Storm Storm (Hurricane Hazel) Highway Q.E.W Lake Ontario Increasing Flow Increasing Flow August 4, 2014 peak flows are between the 100 year event and Regional Storm 28

29 2. Rainfall and Flood Characterization (August 4, 2014) Flood Characterization (Riverine) August 4, 2014 radar data (maximum cell) have been simulated in computer models for all City watersheds to determine where that storm fits in the governing hierarchy East City Watersheds Hager- Rambo Roseland Creek Tuck Creek Shoreacres Creek Appleby Creek Sheldon Creek Regional Aug 4/14 Regional Aug 4/14 Aug 4/14 Regional West City Watersheds Grindstone Creek Stillwater Creek Edgewater Creek Teal Creek Forest Glen Creek La Salle Creek Falcon Creek Indian Creek Regional Aug 4/ Yr 100 Yr Aug 4/ Yr Regional Regional August 4, 2014 (max. cell) and Regional Storm typically govern and peak flows are generally within 10% +/- 100 Year event governs in smaller watersheds (i.e. Aldershot Creeks) 29

30 2. Rainfall and Flood Characterization (August 4, 2014) Conclusions i. Short duration thunderstorms can produce peak flows comparable to longer duration post-tropical events (Regional Storm) ii. The Regional Storm is not an overly conservative event to establish the flood hazard for planning purposes iii. Regional Storm remains an appropriate basis for flood hazard planning in the City of Burlington iv. Current City of Burlington hydrologic models produce conservative results, likely resulting in conservatively sized infrastructure and thereby reduced flood risk 30

31 3. Identification and Prioritization of Flood Vulnerable Areas City-Wide 31

32 3. Identification & Prioritization of Flood Vulnerable Areas City Wide The next stage in the assessment involved determining those locations in the City most vulnerable to flooding: Riverine Roads / Culverts Urban / Depressional areas The August 4, 2014 storm event impacted primarily the central-east portion of the City the resulting flood identified vulnerable areas If a similar storm were centred over the other parts of the City, similar flood impacts could be expected Although the City is responding to address flood vulnerable areas impacted directly by the August 4, 2014 storm (principally Tuck, Roseland, Appleby, Shoreacres), there is a need to proactively identify Flood Vulnerable Areas city-wide 32

33 3. Identification & Prioritization of Flood Vulnerable Areas City Wide Assessment is city-wide Watersheds most impacted by August 4,

34 3. Identification & Prioritization of Flood Vulnerable Areas City Wide Objectives Identify Flood Vulnerable Areas (FVAs), city-wide Assessment is not limited to watersheds impacted by August 4, 2014 storm Identify the mechanism that creates the flood vulnerability e.g. riverine vs. road vs. urban Characterize the relative frequency and magnitude of flood risk for each FVA Characterize each FVA in a systematic and consistent manner such that FVAs can be compared and prioritized in an equitable and consistent manner Identify the most vulnerable areas for flood mitigation planning 34

35 3. Identification & Prioritization of Flood Vulnerable Areas City Wide Methodology - General Distinct and unique analytical approach for Riverine FVAs and Urban FVAs Resulting metrics are common and comparable, allowing defendable prioritization Riverine Flooding Urban Flooding Source: CTV News Source: CTV News Source: Global News Source: Global News 35

36 3. Identification & Prioritization of Flood Vulnerable Areas City Wide Methodology Riverine The Regional (Regulatory) Storm is generally the worst case flood for most City watersheds Regulatory floodplains have been delineated for previous studies Existing Regulatory floodplain limits used to identify all buildings with flood risk (City-wide) Clusters of flood vulnerable buildings grouped into Riverine FVAs Seventy (70) Riverine FVAs identified through this process City-wide 36

37 3. Identification & Prioritization of Flood Vulnerable Areas City Wide Methodology Riverine Break down of FVA s by watershed Watershed No of Riverine FVAs Tuck 13 Shoreacres 9 Appleby 14 Indian 7 Roseland 8 Falcon 5 Sheldon 5 Aldershot 9 Total 70 37

38 3. Identification & Prioritization of Flood Vulnerable Areas City Wide Methodology Riverine 38

39 3. Identification & Prioritization of Flood Vulnerable Areas City Wide Methodology Riverine The flood vulnerability (risk) and potential for flood mitigation vary by FVA In order to allow prioritization of Riverine FVAs, more information on the degree of flood vulnerability is required Buildings that are flood vulnerable for more frequent storms are a higher priority for mitigation E.g. a building that floods at a simulated 25 year frequency, is a higher priority to a building that floods for a simulated 100 year event Hydrologic and hydraulic computer modelling is required to determine the degree of vulnerability 39

40 3. Identification & Prioritization of Flood Vulnerable Areas City Wide Methodology Riverine City s existing numerical hydrologic and hydraulic models used Hydrologic model (flows) Input: drainage area, land use, soils, rainfall Output: runoff (flow, volume) Hydraulic model (levels) Input: river geometry, peak flow Output: flood level, velocity 40

41 3. Identification & Prioritization of Flood Vulnerable Areas City Wide Methodology Riverine Flood levels simulated for the 2 to 100 year, August 4, 2014 and Regional Storm events Flood levels are then compared to building ground elevations to determine the frequency at which they are vulnerable Regional WSEL 41

42 3. Identification & Prioritization of Flood Vulnerable Areas City Wide Methodology Riverine - Flood Vulnerable Roads (FVRs) All primary culverts/bridges city-wide were assessed to determine whether they meet current design guidelines (132 +/- culverts / bridges): Ministry of Transportation (MTO) specifies the storm event that should be conveyed by a certain road class (e.g. urban collector) without overtopping Ministry of Natural Resources & Forestry (MNRF) outlines criteria for emergency/passenger vehicle and pedestrian ingress/egress based on overtopping depth and velocity Roads are designed to overtop at a certain frequency overtopping does not mean failure Although FVRs could be prioritized based on overtopping frequency, the primary priority for upgrading culverts/bridges is when an undersized opening causes flood impacts on property upstream (identified through the Riverine FVA process) 42

43 3. Identification & Prioritization of Flood Vulnerable Areas City Wide Results Riverine Summary of City-wide results: Residential uses make up 90% of flood vulnerable buildings Low Density Residential is the most vulnerable land use (77%) Primarily related to historic development practices (pre-1970 s) in the southern part of the city when floodplains were not regulated as they are today SUMMARY OF FLOOD VULNERABLE BUILDINGS BY WATERSHED & LAND USE Total Number of Flood Vulnerable Buildings Watershed ID Grand Total Residential Medium Density Residential Residential Commercial Employment Low Density High Density Zones Mixed Use Corridor Open Space / Park /Utility City Wide

44 3. Identification & Prioritization of Flood Vulnerable Areas City Wide Results Riverine Summary of city-wide results Most vulnerable watersheds were also those hardest hit by August 4, 2014 Summary Of Flood Vulnerable Buildings By Watershed & Return Period Watershed Total Number of Flood Vulnerable Buildings Grindstone Creek N/A Aldershot Creeks 10 Falcon Creek 30 Indian Creek 64 Hager-Rambo N/A Roseland Creek 111 Tuck Creek 188 Appleby Creek 84 Shoreacres Creek 22 Sheldon Creek 17 Bronte Creek 0 City Wide

45 3. Identification & Prioritization of Flood Vulnerable Areas City Wide Results Riverine Specific details summarized for each Riverine FVA: Number of buildings at risk Land use Frequency of flood vulnerability (risk) A Flood Score has been generated for each Riverine FVA as a measure of flood risk The Flood Score has been used to prioritize the Riverine FVAs relative to each other using consistent methodology (comparative basis) 45

46 3. Identification & Prioritization of Flood Vulnerable Areas City Wide Results Riverine Top 10 Priority Areas Priority FVA Watershed Score Total No. of Flood Vulnerable Buildings 1 RTK3 Tuck RRO6 Roseland RTK4 Tuck RRO4 Roseland RTK2 Tuck RAP7 Appleby RRO5 Roseland RTK6 Tuck RFA4 Falcon RFA3 Falcon

47 3. Identification & Prioritization of Flood Vulnerable Areas City Wide Climate Change Assessment Global Climate Change Model (GCM) Data (forecasts) are available from the World Climate Research Programme (WCRP) Coupled Model Intercomparison Project Phase 3 (CIMP3) Dozens of models available from various countries Each GCM has been run for a range of predicted severity in climate change (low, moderate, severe), including ensembles (averages) Significant range of results given variability the best approach is to use the average Relative Change in Rainfall Depth Relative Change 70% 60% 50% 40% 30% 20% 10% 0% -10% -20% Return Period (Years) Average or Median 47

48 3. Identification & Prioritization of Flood Vulnerable Areas City Wide Climate Change Assessment GCM data is coarse. It is downscaled using Regional models for application to a smaller geographical area (e.g. Ontario) IDF-CC Tool (University of Western, Canadian Water Network, 2015) has been applied Incorporates results from several GCMs Provides climate change forecasts by way of direct modification of the Environment Canada rainfall data that the City of Burlington currently uses to design infrastructure Two (2) climate change rainfall scenarios have been created and have been simulated in City models: Year % +/- increase in rainfall depth Year % +/- increase in rainfall depth 48

49 3. Identification & Prioritization of Flood Vulnerable Areas City Wide Climate Change Assessment Additional analysis has been completed to calculate peak flows and flood levels using the climate change rainfall scenarios The analysis (ongoing) enhances the Riverine assessment: Assess the performance of existing infrastructure under future rainfall conditions (e.g. FVRs) Characterize the future vulnerability of FVAs and compare to the current vulnerability (e.g. does the priority of certain FVAs change in the future) Plan and design new infrastructure, including flood mitigation projects, for future climate conditions 49

50 3. Identification & Prioritization of Flood Vulnerable Areas City Wide Methodology Urban Urban FVAs have been identified by locating depression areas, or areas that do not have a positive surface outlet satisfying following criteria: Potential flood depth > 0.5 m drainage area > 1.0 ha Must be outside of floodplain (riverine) This has been achieved by way of a GIS assessment using City mapping 50

51 3. Identification & Prioritization of Flood Vulnerable Areas City Wide Methodology Urban Urban FVA s do not consider for the presence of storm sewers, and therefore represent vulnerability only when storm sewers are blocked or their capacity is exceeded The presence of reverse-grade driveways dramatically increases the flood vulnerability as this presents potential for direct impacts A Flood Score has been generated for each Urban FVA based on Number of reverse driveways (buildings at risk) Length of impacted road (i.e. impact to ingress/egress) Professional judgement has been used to screen those areas at lower risk due to other factors 51

52 3. Identification & Prioritization of Flood Vulnerable Areas City Wide 52

53 3. Identification & Prioritization of Flood Vulnerable Areas City Wide Results Urban One-hundred ten (110) Urban FVAs have been identified with Top 10 priority areas as follows: Priority FVA Watershed Flood Score Flood Impact Buildings (#) Road No. Reverse Driveways Length (m) 1 URO3 Roseland UAP21 Appleby USE8 Sheldon USO7 Shoreacres UAP19 Appleby URO9 Roseland UHRL5 Lower Hager-Rambo URO4 Roseland UHRL6 Lower Hager-Rambo USO9 Shoreacres

54 3. Identification & Prioritization of Flood Vulnerable Areas City Wide Summary City-Wide 70 Flood Vulnerable Areas (Riverine) 132 Culverts/Bridges (Roads) 110 Urban Flood Vulnerable Area s 54

55 4. Preliminary Flood Mitigation Opportunities 55

56 4. Preliminary Flood Mitigation Opportunities Methodology 1. For each flood mechanism (Riverine, Road, Urban) a long-list of opportunities established 2. These have been screened to a short-list based on FVA specific opportunities Is a downstream culvert impacting flood levels? Is there potential for spills between watercourses? Are there upstream stormwater management opportunities? Other localized factors 3. Technically evaluated the short-list (using modelling) to determine the potential reduction in flooding (i.e. the benefit) 4. Developed preliminary cost estimates considering further study, design, and capital costs 5. Determined and compared each potential project relative to others 6. Used the high-level benefit assessment, in conjunction with other considerations (flood vulnerability, capital planning, progressive judgement etc) to select priority projects for implementation including City staff consultation 56

57 4. Preliminary Flood Mitigation Opportunities Long-List of Flood Mitigation Opportunities Riverine Stormwater Management Online Over-control new development Conveyance Improvements Culvert upgrade Channelization Diversion Flood Proofing Berming or Flood Wall Building flood proofing Property Acquisition Note: Solutions may not be 100% effective but all would reduce risk 57

58 4. Preliminary Flood Mitigation Opportunities Hager-Rambo Flood Control Historical example of diversion and flood storage Hager-Rambo Diversion Channel Hager-Rambo Flood Control Facility 58

59 4. Preliminary Flood Mitigation Opportunities Long-List of Flood Mitigation Opportunities Urban (depressions) Stormwater Management Conveyance Improvements Sewer upgrades Major system upgrades Diversions Flood Proofing Building flood proofing Property Acquisition 59

60 4. Preliminary Flood Mitigation Opportunities Short-List Evaluation (by example) Typical Riverine FVAs Short-List Alternatives 1. Upgrade selected culverts 2. Upgrade culverts and improve channel 3. Acquire property to facilitate larger culvert upgrades and wider channel 60

61 4. Preliminary Flood Mitigation Opportunities Short-List Evaluation Process The impact / benefit of each short-listed alternative (system improvement) was technically assessed as to: Reduced flooding depths Reduced flooding extents The alternative s relative benefit was then compared to the base condition and a new / updated Flood Score calculated Preliminary capital cost estimates for each short-listed alternative was then determined A pseudo cost-benefit score established in order to determine the most effective solution 61

62 4. Preliminary Flood Mitigation Opportunities Watershed Scale Stormwater Management In addition to FVA specific solutions (generally conveyance), stormwater management (flood control storage) opportunities have also been identified in priority watersheds 62

63 4. Preliminary Flood Mitigation Opportunities Watershed Scale Stormwater Management The best flood control opportunities in Roseland, Tuck, Falcon and Indian Creeks have been evaluated notably: Total reduction in Flood Score for the benefitting FVAs downstream was calculated Capital cost was estimated Cost-benefit score was calculated and used in comparison analysis 63

64 4. Preliminary Flood Mitigation Opportunities Recommended Projects (preferred solutions) The short-list evaluation has been completed for the top priority FVAs as well as watershed scale stormwater management opportunities The resulting benefit cost score for each mitigation opportunity has been determined and compared relatively A recommended list of projects has been advanced on the basis of: Greatest flood vulnerability Highest cost-benefit of flood mitigation Consultation with City staff including professional judgement The overall methodology ensures the City of Burlington is investing in flood mitigation in the most effective way possible (i.e. greatest flood relief per dollar) 64

65 4. Preliminary Flood Mitigation Opportunities Recommended Projects Watershed Project Cost Tuck Creek Tuck Creek Upgrade Regal Rd culvert and channelization between New St and Regal Rd Upgrade New St culvert and channelization upstream of New St. $3.50M $3.80M Tuck Creek Upgrade Spruce Ave culvert $1.36M Roseland Creek Upgrade Lakeshore Rd culvert $2.10M Appleby Creek Channelization of creek south of Fairview St., along bike path and culvert upgrade at Pinedale $2.76M Roseland Creek Upgrade New St. culvert $3.60M Roseland Creek Tuck Creek Construct SWM pond on Leon s property north of North Service Rd Upgrade Rexway Dr culvert $3.70M $1.37M Falcon Creek Construct Stormwater Management Pond $2.0M Tuck Creek Upgrade Rockwood Dr culvert $1.37M 65

66 4. Preliminary Flood Mitigation Opportunities Implementation Process Class Environmental Assessment Amec Foster Wheeler has consulted with MOECC Some work is essentially exempt Schedule A/A+ Eg, sewer upgrades, operations and maintenance, work within ROW Other work is more complex will require due consideration of broader environment Social Economics Natural Functional Current study serves as a City-wide Scan/Audit of Flood Risk to establish priorities Objective will be to develop area-specific Master Plans and incorporate extensive consultation with Agencies and Public (i.e. Resident Advisory Committee) 66

67 5. Site Specific Flood Mitigation Projects (in response to August 4, 2014) 67

68 5. Site Specific Flood Mitigation Projects (in response to August 4, 2014) Activities initiated concurrently with Phase 1 Study Sixteen (16) FVAs identified by City staff for immediate assessment Criteria of selection Observed and reported flooding impacts associated with August 4, 2014 event Projects related to historic or ongoing drainage problems Prioritized schedule of FVAs for mitigation 68

69 5. Site Specific Flood Mitigation Projects (in response to August 4, 2014) 69

70 5. Site Specific Flood Mitigation Projects (in response to August 4, 2014) Recommended Projects No. Location Watershed Flood Mechanism 1 Brant Cavendish Dr. East Rambo Creek Surface flooding due to insufficient inlet capacity 2 Grenallen Dr. Hydro ROW East Rambo Creek Surface flooding due to insufficient inlet capacity and local grading in ROW 3 Bennett Road Hydro ROW Appleby Creek Surface flooding due to insufficient inlet capacity and local grading in ROW 4 Hadfield Court Appleby Creek Surface and/or basement flooding related to local minor/major system 5 Ingersoll Drive Roseland Creek Surface and/or basement flooding related to local minor/major system 6 Beaufort Drive East Rambo Creek Riverine flooding 7 Ayr Place Shoreacres Creek Surface and basement flooding related to local minor/major system Itabashi Way Shoreacres Creek Riverine flooding 9 Auburn Crescent Shoreacres Creek 10 Bristol Drive Tuck Creek Basement flooding related to local minor/major system and reverse driveway grading Basement flooding related to local minor/major system and reverse driveway grading 11 Driftwood Park Tuck Creek Riverine flooding, potentially related to inlet/culvert capacity 12 Mullin Way Appleby Creek Basement heaving/cracking due to potentially surcharged foundation 13 Bridle Wood Appleby Creek drains/storm sewers and elevated groundwater levels. 14 Ashland Drive Appleby Creek 15 Shoreacres Hwy 407 Shoreacres/Tuck Riverine spill along Highway 407 (Shoreacres to Tuck) 16 Kirkburn/Overton Drive Roseland/Tuck Surface flooding, potentially related to inlet/culvert capacity 70

71 5. Site Specific Flood Mitigation Projects (in response to August 4, 2014) Solutions for Phase 2 projects are in progress General types of solutions include: Upgrades to inlets Regrading Repairs Repairs to erosion / scour Public education Consultation is on-going with City Staff and other Stakeholders 71

72 6. Summary of Recommendations 72

73 6. Summary of Recommendations Enhanced Data Management & GIS Mapping Coordinated with Conservation Halton 73

74 6. Summary of Recommendations Conservation Halton Recommendations CH/City to investigate flood mitigation measures on Tuck Creek north of New St. CH/City to investigate runoff diverted from Shoreacres Creek into Tuck 407 ETR. In cooperation with Halton Region and City, assess the rainfall and streamflow gauge system in Burlington. Consideration be given to updating watershed studies for Roseland, Tuck, Shoreacres, Appleby and Sheldon Creeks. 74

75 6. Summary of Recommendations Halton Region Recommendations Undertake approximately $60M in system improvement projects. Develop an inter-jurisdictional basement flooding working group. Establish a permanent wastewater flow monitoring/metering program. Develop a voluntary downspout disconnection program based on 100 per cent subsidy for eligible residents. Develop a voluntary weeping tile disconnection program based on 100 per cent subsidy for eligible residents. Develop an extraneous flow reduction public education program. Establish dedicated staff resources to develop, implement, sustain and monitor the Region wide basement flooding mitigation program. 75

76 6. Summary of Recommendations City of Burlington Recommendations Include $20.04M in storm water infrastructure improvements for consideration in the 2016 Capital Budget and Capital Forecast. Undertake a Storm Water User Fee Implementation Study (est. cost $250,000). Extend, to the end of 2016, the grant program to offset the cost of plumbing permit fees for the installation of backwater valves, disconnection of foundation drains and installation of sump pumps. 76

77 6. Summary of Recommendations City of Burlington Recommendations (continued) Report back to D&I Committee annually on the progress of the Flood Vulnerability, Prioritization and Mitigation program, prior to the Capital Budget approvals. Approve the addition of a full-time stormwater management technician in the Development and Environmental Engineering section of the Capital Works Department. Undertake a public consultation and outreach program to advise residents of the recommendations of report CW

78 7. Actions Moving Forward 78

79 7. Actions Moving Forward 1. Phase 2 Flood Mitigation Project implementation. 2. Assist Halton Region with downspout disconnection program. 3. Coordinate with Conservation Halton to finalize revised authorization and permitting protocols for routine and emergency maintenance works in regulated floodplains and watercourses. 4. Creek Condition Inventory Inspection with enhanced scope of work. 5. Public Engagement neighbourhood meetings regarding report recommendations. 6. Assessment of effectiveness of RPM $100,000 additional creek maintenance funding prior to 2016 Capital Budget. 7. Storm Water Capital Budget modifications. 8. Storm Water User Fee Implementation Study. 9. Extend Plumbing Permit grant program to

80 7. Actions Moving Forward 10. Data management and GIS enhancements. 11. Continue to coordinate with Halton Region on the Basement Flooding Prevention Subsidy Program. 12. Further analysis of Urban Flood Vulnerable Areas and potential overland flow routes. 13. Storm Water design standards review. 14. Update watershed models. 15. Review and revise current By-laws & policies. 16. Regular coordination meetings with 407 ETR, MTO & CN. 17. Continue to monitor climate change and impacts to infrastructure. 18. Coordinate with Halton Region & Conservation Halton on the SWM design for Dundas Street widening. 80

81 81 Thank You