WILLIAM STREET STORM SEWER OUTFALL Municipal Class Environmental Assessment PUBLIC INFORMATION CENTRE March 23, 2017
ACCESSIBILITY Under the Accessibility Standards 2015 for Customer Service Regulation (2008), the City of London (City) is committed to ensuring that public participation opportunities are accessible to all participants. This Public Information Centre (PIC) incorporates the following accessibility features: Accessible venue location for persons with disabilities, including wheelchair ramps, accessible washrooms, parking and elevators For persons requiring assistance, project team members will: o Explain presentation board content o Assist with the preparation and submission of comment forms Reading aids are available, including magnifying glasses. 2
WELCOME The City s Old North Servicing Strategy identified the need to improve drainage in the Old North neighbourhood, which will include constructing a new trunk storm sewer on William Street between Huron Street and Grosvenor Street. The storm sewer will be constructed over a number of years, with the first phase including upgrades to the existing outlet at the end of William Street., in Huron Street Woods. OUTLINE the Class EA process and why the Old North/William Street Trunk Storm Sewer Class EA Study was initiated by the City SUMMARIZE existing conditions in the Study Area IDENTIFY alternatives considered and the recommended alternative RECEIVE public and agency input on the recommended alternative OUTLINE the next steps in the study 3
CLASS ENVIRONMENTAL ASSESSMENT PROCESS PHASE 1: Problem/ Opportunity PHASE 2: Alternative Solutions PHASE 3: Design Options for Preferred Solution PHASE 4: Environmental Study Report (ESR) PHASE 5: Implementation Identify problems/ opportunities to be addressed in the planning and design process Prepare a Problem Statement Develop alternative design solutions to address problems/opportunities Overview of existing and future conditions Consultation with review agencies and the public Complete an impact assessment of the preferred alternative Prepare report documenting the study process Identify design options for the preferred solution Detailed overview of existing/future conditions Evaluate design options and select a preferred design option Consultation with review agencies and the public Complete an impact assessment of the preferred design option Document the decisionmaking process in an ESR for a Schedule C project Design and construction phase Project must be designed and constructed as outlined in the ESR WE ARE HERE PUBLIC INFORMATION CENTRE March 23, 2017 The Study is following the requirements of the Municipal Class Environmental Assessment (EA) (2015). The study was initiated as a Schedule B project, which follows Phases 1 and 2 of the Class EA process. The Class EA schedule will be confirmed when the preferred alternative is selected. There is potential for the project to be re-classified as a Schedule A+ project, which is considered pre-approved and a Class EA is not required. The Class EA process ensures: All relevant social, environmental and engineering factors are considered in the planning and design process Public and agency input is integrated into the EA process. 4
STUDY AREA -5
PROBLEM/OPPORTUNITY The Old North Servicing Strategy was completed in 2014 to develop a storm, sanitary and water servicing strategy for the Old North neighbourhood. Improvements to the existing Huron Creek storm outfall and natural channel were identified as a priority in the strategy. Problem/Opportunity: The Cheapside Street corridor, William Street and several other local streets in Old North require the combined sewers to be separated. The existing outfall structure and channel in Huron Street Woods does not have the capacity to accommodate additional flows from the new storm sewers. The outfall structure and channel need to be improved to accommodate increased flows and mitigate environmental impacts. 6
EXISTING CONDITIONS 2015 Channel and outfall cannot handle existing flows. Conditions include flooding and deterioration of multiuse pathway. 2015 2017 Open/aquatic swamp is a pond feature created by beaver activity. 2017 Significant changes in the area between 2015 and 2017. The existing open pond/swamp feature has the potential to impact the Thames Valley Parkway during significant storm events. 7
EXISTING CONDITIONS NATURAL ENVIRONMENT Ecological investigations in the potential impact area will be used to develop the recommended alternative. An Environmental Impact Study will be completed to document the investigation. Amphibian survey completed spring 2016 Surveys of plants, birds and fish will be completed in spring 2017 Potential for several Species at Risk (SAR) to occur in the area, which will be confirmed Huron Street Woods is a Significant Woodland that includes deciduous forest and open/aquatic swamp habitats. Photo credit: Walter Muma Native and exotic plants identified in 2016 survey. Flows from the outfall eventually reach the North Thames River. Photo credit: Ontario Wildflowers New England Aster Common Buckthorn 8
EXISTING CONDITIONS BEAVERS There is evidence of significant beaver activity in the vicinity of the outfall. Council has adopted a Beaver Protocol to implement the City s Humane Urban Wildlife Conflict Policy. The protocol balances competing priorities, including: Respect and protect beavers in their natural habitat Allow for enhancements to biodiversity and the creation of wetland environments Study Area Educate the public about the value of beaver created wetlands Protect critical infrastructure Protect people and property from flooding Maintain the use of the City s pathway and trail system. The Beaver Protocol will be applied to works required for this project. Photo Credit: Wikipedia 2017 9
CONSTRAINTS/OPPORTUNITIES The following was considered when developing alternatives to address the problem/opportunity: Constraints Poor soil conditions for construction work Slope stability north of Harrison Crescent, some of Study Area which is on private property Existing critical trunk transmission watermain in the area Opportunities Provide storm sewers to areas where they currently don t exist Improve the environment by eliminating combined sewer flows Allow reconstruction and upgrading of local infrastructure Flooding and beaver activity near Thames Valley Parkway Existing outfall channel 10
ALTERNATIVE 1 - RECOMMENDED Description: Basic channel improvements from the existing headwall to the maintenance road Replace existing culvert with a larger culvert or bridge Maintain existing open aquatic/swamp feature but eliminate significant water ponding Pros Reduce flooding and standing water on the Thames Valley Parkway Minimal impact on existing watermain Minimal impact on natural environment Improved drainage Lowest construction cost Construction practical despite soil conditions Eliminate standing water at top of slope at rear of Harrison Crescent properties. Legend Multi-Use Path Existing Storm Maintenance Hole Existing Water Drain Chamber Structure Existing 1800 mm Storm Sewer Existing 600mm Watermain Low Flow Channel Water Grading Cons Potential for culvert to be impacted by beaver activity in the future 11
ALTERNATIVE 2 NOT RECOMMENDED Description Remove existing headwall Extend storm sewer approximately 35m Install new energy dissipating headwall Replace existing culvert with a larger culvert or bridge Maintain existing open aquatic/swamp feature but eliminate significant water ponding Pros Reduce flooding and standing water on the Thames Valley Parkway Impacts of increased flow are reduced (i.e. storm flow is contained in sewer longer) Minimal impact on natural environment Legend Multi-Use Path New Storm Maintenance Hole Existing Storm Maintenance Hole Existing Water Drain Chamber Structure New Storm Sewer Existing 1800mm Storm Sewer Existing 600mm Watermain Low Flow Channel Water Grading Cons Potential for culvert to be impacted by beaver activity Construction not cost effective due to existing soil conditions Impact on existing watermain due to poor soil conditions (i.e. high water table and approximately 2.5m thick organic layer) 12
ALTERNATIVE 3 NOT RECOMMENDED Description Remove existing headwall and culvert Extend storm sewer under maintenance road before outletting to the existing channel Install new energy dissipating headwall Maintain existing open aquatic/swamp feature but eliminate significant water ponding Pros Reduce flooding and standing water on the Thames Valley Parkway Reduce standing water Legend Multi-Use Path New Storm Maintenance Hole Existing Storm Maintenance Hole Existing Water Drain Chamber New Inlet Structure New Storm Sewer Existing 1800 mm Storm Sewer Existing 600mm Watermain Low Flow Channel Grading Cons Greater impact on natural environment Construction not cost effective due to existing soil conditions Greater impact on existing watermain due to poor soil conditions (i.e. high water table and approximately 2.5m thick organic layer) 13
ALTERNATIVE 4 NOT RECOMMENDED Description Remove existing headwall and culvert Extend storm sewer under maintenance road before outletting to the existing channel Install new energy dissipating headwall Install drain to direct overland flow to the storm sewer Grade and plant existing open aquatic/swamp feature using native species Pros Reduce flooding and standing water on the Thames Valley Parkway Legend Multi-Use Path New Storm Maintenance Hole Existing Storm Maintenance Hole Existing Water Drain Chamber Ditch Inlet Catch Basin Structure New Storm Sewer Existing Storm Sewer Existing 600mm Watermain Low Flow Channel Naturalized Area Grading Cons Greatest impact on natural environment Construction not cost effective due to existing soil conditions Impact on existing watermain due to poor soil conditions (i.e. high water table and approximately 2.5m thick organic layer) 14
RECOMMENDED ALTERNATIVE Alternative 1 is recommended: Meets objective to improve the storm sewer outfall and channel to accommodate increased flows Lowest impact on the natural environment and watermain Practical to construct despite soil conditions Lowest construction cost. Alternative 1 provides a balance between accommodating increased stormwater flows and minimizing disturbance in the Huron Street Significant Woodlot. Due to the limited impact and scope of work, this alternative is identified as a Schedule A+ activity under the Class EA. It is considered pre-approved and does not require an environmental assessment report to be prepared. The public will be advised prior to the implementation of the project. 15
NEXT STEPS 2017 2018 2018 THANK YOU FOR ATTENDING! Spring Summer Fall Winter Spring Summer Fall Your input is important to the outcome of this project. RESPOND TO INPUT PROVIDED Please complete and return a comment form by April 6, 2017 COMPLETE FIELD INVESTIGATIONS COMPLETE EA STUDY DETAILED DESIGN POTENTIAL CONSTRUCTION START Jason Johnson, P.Eng. Project Manager Dillon Consulting Limited 130 Dufferin Ave. Suite 1400 London, ON, N6A 4W7 Tel: 519-438-1288 Ext. 1222 Email: WilliamStreet@dillon.ca Kyle Chambers, P.Eng., Wastewater and Drainage Engineering City of London P.O. Box 5035 300 Dufferin Ave. London, ON, N6A 4L9 Tel: 519-661-2500 Ext. 5854 Email: kjchambe@london.ca Personal information collected and recorded at the Public Information Centre or submitted in writing on this subject is collected under the authority of the Municipal Act, 2011 and will be used by members of Council and City of London staff in their review of this matter. With the exception of personal information, all comments will become part of the public record. Questions about this collection should be referred to the City Clerk s office at 519-661-2500. 16