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Home My WebLink AboutINS-13-019 - Stirling Ave North - Environmental Assessment REPORT TO:Community & Infrastructure Services Committee DATE OF MEETING: April 22, 2013 SUBMITTED BY: Steve Allen, Manager, Engineering Design and Approvals (519-741-2200 x 7584 PREPARED BY: Diana Lupsa, Design & Construction Project Manager (519- 741-2200 x 7815) WARD(S) INVOLVED: 10 DATE OF REPORT: April 16, 2013 REPORT NO.: INS-13-019 SUBJECT: STIRLING AVENUE NORTH - FLOOD MITIGATION – SCHEDULE B CLASS ENVIRONMENTAL ASSESSMENT RECOMMENDATION: THAT the Stirling Avenue North Flood Mitigation Schedule B Class Environmental Study Report (ESR) prepared by The WalterFedy Partnership dated April 16, 2013 be received; and further; THAT the Stirling Avenue North Flood Mitigation Schedule B Class Environmental Study Report (ESR) be filed with the Ontario Ministry of the Environment for the mandatory thirty (30) day review period as required by the Environmental Assessment Act. BACKGROUND: Over the last 30 to 40 years, residents have experienced on-street flooding at the termination of Stirling Avenue North on the west side of the Parkway. The extent of flooding has impacted private property and basements have been flooded on numerous occasions. The City of Kitchener’s design criteria for storm sewer infrastructure requires that the storm sewers (minor system) have adequate capacity to convey flows from the 5-year return interval rainfall event and that a major overland flow route be provided to convey flows from the 100-year return interval rainfall event. Based on the frequency of resident complaints regarding flooding and observations made by City of Kitchener Staff, it is apparent that the current storm sewer infrastructure does not comply with the noted design criteria. Reviews of the storm sewer infrastructure, completed by the City of Kitchener, indicate capacity constraints on Stirling Avenue, crossing beneath the Parkway and continuing at various downstream locations to the outlet at Montgomery Creek. To address the flooding issue, the City initiated a Schedule B Class Environmental Assessment (EA) in order to ensure public participation. In July 2012, the City retained WalterFedy as consultants to complete a Class EA in order to identify cost effective solutions to correct this 8 - 1 flooding situation and to implement a preferred solution as part of the reconstruction of Stirling Avenue North. The Class EA was undertaken in accordance with Municipal Engineers Association document, October 2000, as amended in 2007. The Class EA process included consultation with the public, agencies and stakeholders through the issuance of a Notice of Commencement, the development and regular updating of a contact list and one Public Information Centre (PIC) to present the proposed alternatives and receive comments. The City of Kitchener intends to upgrade the underground services to current standards and carry out complete roadway reconstruction of Stirling Avenue North (from Weber Street to the East End). The infrastructure for Stirling Avenue North has generally reached the end of its useful life and requires full replacement and it is to be completed in two phases over two construction seasons (2013 and 2014). It is expected that the preferred solution for the flooding will be implemented in conjunction with the first phase of the road reconstruction. REPORT: During the Class EA process six (6) alternatives were evaluated against the following criteria: Social impacts; Economic impacts; and Overall flood mitigation benefits Four alternatives were presented at the PIC, but they have been modified and two more have been added based on input from internal staff, stakeholders and public. The alternatives are: Alternative 1 - Do Nothing The Do Nothing alternative is a standard consideration for all Class EA projects where the existing conditions are left as is, and no further analysis or work is done. In this case, the Do-Nothing alternative would result in no change to the current flooding situation. The roadway would continue to flood and there would continue to be impacts to private property including basement flooding. Alterative 2 –Acquire Impacted Properties This alternative does not involve any changes to the current storm sewer infrastructure and there would continue to be flooding. This conceptual alternative would involve purchasing the property and homes of those residents that experience the most impact to private property (i.e. 356 Stirling Avenue and 468 Dumfries Avenue, see Fig. 1).This alternative has significant social impacts involving the relocation of residents and the upheaval that this would cause in their lives. 8 - 2 Upgrade Downstream Storm Sewers Alternative 3 – This alternative would involve diverting some flow from East Avenue and Glendale Road to Krug Street, installing a larger diameter storm sewer beneath the Parkway as well as upgrading sections of the downstream trunk storm sewer (Archer Place, Lyndhurst Drive and Nottingham Avenue). The capital cost associated with this alternative is estimated to be $3.7 Million. Divert Flows to Centennial Stadium (South) Sewer, Upgrade the Existing Alternative 4 – South Sewer and Upgrade Downstream Storm Sewers Currently, there are two storm sewers crossing beneath the Conestoga Parkway. One, is a 600 mm diameter pipe at the end of Stirling North Avenue (the Stirling Avenue outlet North). The second one, is a 750 mm diameter pipe, servicing the Auditorium lands (Centennial Stadium outlet South). This alternative is proposing diverting the flows from the north crossing to the south crossing. This alternative involves the following: the diversion of storm flow at East Avenue and Glendale Road towards Krug Street; diversion of flows from the existing 600 mm diameter Stirling Avenue outlet (North) to the 750 mm diameter Centennial Stadium outlet (South) and abandonment of the North (existing) outlet; increasing the size of the south Parkway crossing from 750 mm to 1,500 mm diameter; and increasing the size of the downstream storm sewers to the outlet at Montgomery Creek to 1,500 mm diameter. Modelling indicates that this alternative would eliminate flooding for all storms up to and including the 100-year return interval rainfall event. The capital cost associated with this alternative is estimated to be $2.7 Million. Alternative 5 - Divert Flows to Centennial Stadium (South) Sewer, Utilize Existing South Crossing and Upgrade Stirling Avenue Storm Sewers to 1,350 mm Diameter This alternative involves the following: the diversion of storm flow at East Avenue and Glendale Road towards Krug Street; diversion of all flows from the existing 600 mm diameter Stirling Avenue outlet (North) to the 750 mm diameter Centennial Stadium outlet (South) and abandonment of the North (existing) outlet; utilizing the existing south Parkway 750 mm diameter crossing; and increasing the size of the storm sewers on Stirling Avenue to 1,350 mm diameter to provide storage within the right of way. Modelling indicates that this alternative would reduce but not eliminate flooding. This alternative would eliminate basement flooding. There would still be some occurrences of on street flooding, however, the severity would be greatly reduced. The capital cost associated with this alternative is estimated to be $500,000. 8 - 3 Alternative 6 – Divert Flows to Centennial Stadium (South) Sewer, Utilize Existing South Crossing and Upgrade Stirling Avenue Storm Sewers to 1,350 mm Diameter, Provide Storage for Excess Flows This alternative incorporates all of the elements of Alternative 5 with the introduction of a storage element prior to discharging the Stirling Avenue flows to the Centennial Stadium (South) Sewer. The goal of this alternative was to further reduce the depth of expected flooding by providing storage for the excess flows and gradually releasing them to the storm sewer system over an extended period. The storage volume required to provide this level of flood control is approximately 4,900 cubic metres. This alternative would still result in some minor on street flooding, however, it is expected that there would be no impact to private property as the flooding would be contained within the road right-of-way. The required storage volume could be provided on the property of the Kitchener Memorial Auditorium Complex (Auditorium) either by a quantity control pond located in the north-east corner, surface parking lot storage or below grade storage units. The future use of the Auditorium lands is not known at this time so a decision regarding the method of providing storage must be deferred. The estimated capital cost associated with this alternative is $875,000. The preferred alternative is Alternative 6 – Divert Flows to Centennial Stadium (South) Sewer, Utilize Existing South Crossing and Upgrade Stirling Avenue Storm Sewers to 1,350 mm Diameter, Provide Storage for Excess Flows. A schematic of this alternative is provided in Figure 2. The Preferred Alternative involves the following components: 1. the diversion of flows to Krug Street at East Avenue and Glendale Road; 2. diversion of flows from the existing 600 mm diameter Stirling Avenue outlet (North) to the 750 mm diameter Centennial Stadium outlet (South); 3. utilizing the existing south Parkway 750 mm diameter crossing; 4. increasing the size of the storm sewers on Stirling Avenue to 1,350 mm diameter to provide storage and some attenuation of flows; and 5. provision of approximately 4,900 cubic meters of storage. The Preferred Alternative will be implemented in a staged manner. Stage 1 will involve the first four components and they will be included in the tender and construction phase of the Stirling Avenue North Road reconstruction project. Stage 2 will be the fifth component, the off road storage within the Auditorium lands, and it will be implemented once a decision regarding the future expansion of the Auditorium will be made. The storage will be integrated into the Auditorium expansion plans. 8 - 4 FINANCIAL IMPLICATIONS: This project was identified in the City’s 2013 Capital Forecast. The estimated cost for the preferred Alternative 6 would be approximately $875,000.00. Funding has been included in the 2013 Capital budget. COMMUNITY ENGAGEMENT: As part of the Class EA process Notices of study commencement and open house were published in the newspaper, The Record. The public information (PIC) was conducted on January 17, 2013 at the Auditorium. At the PIC, study findings and conceptual alternatives were presented, and comments from the public were obtained. The following details were presented at the PICs: Class EA process Background Purpose statement Alternative solutions Evaluation criteria of Alternative solutions Preferred alternative Cost estimate Project Schedule Next steps Frequently asked Questions with regards to the EA process and how the public can be involved in the process Comment Sheet In addition to the PIC a number of meetings were held with City staff regarding the Auditorium lands. Input from various internal departments was taken into consideration when selecting the preferred alternative. CONCLUSION: Currently, localized flooding at the end of Stirling Avenue to the west of the Conestoga Parkway impacts and damages private property and creates safety as well as maintenance and access issues. Staff is recommending the proposed Alternative 6 to Divert Flows to Centennial Stadium (South) Sewer, Utilize Existing South Crossing and Upgrade Stirling Avenue Storm Sewers to 1,350 mm Diameter, Provide Storage for Excess Flows. Therefore Staff recommends that the Stirling Avenue North Flood Mitigation Schedule B Class Environmental Assessment Report be filed with the Ontario Ministry of the Environment for the mandatory thirty (30) day review period as required by the Environmental Assessment Act. 8 - 5 ACKNOWLEDGED BY: Pauline Houston, Deputy CAO Infrastructure Services Department 8 - 6 Fig. 1 - Flooding Area (around 356 Stirling Avenue and 468 Dumfries Avenue ) and the exisiting 600 mm diameter Stirling Avenue crossing under the HWY 8 Flooding Area (around 356 Stirling Avenue and 468 Dumfries Avenue) Stirling Avenue outlet (North) 8 - 7 Fig.2 - Schematic of thePreferred Alternative – Alternative 6 Stirling Avenue Storm Sewers Centennial Stadium outlet (South) 8 - 8