Infrastructure Master Plan Components
Development of the IMP is currently in progress, including several major components that address drinking water, wastewater, and stormwater management required to support the Official Plan objectives. The IMP will also enable associated greenfield and intensification development in urban areas and rural villages. A status update on key aspects of the plan and preliminary conclusions are provided below.
Intensification Capacity Management
The City is completing several studies to support the management of infrastructure capacity as intensification increases in existing neighbourhoods. These studies fall into the following three categories:
- Review of best practices in place in other major Canadian cities;
- Analysis of local water distribution and wastewater collection systems performance in existing neighbourhoods; and
- Review of strategic options for managing stormwater.
Through these studies, the following must be taken into consideration when developing the new IMP:
- Existing grading and development constraints limit opportunities to improve storm drainage system capacities;
- A regulatory mechanism will be required to enforce on-site stormwater management on virtually all intensification development projects where there is an increase in imperviousness. The proposed approach includes development of a design guide, sizing tables, approved servicing concept illustrations and standard drawings to simplify the design process for property owners;
- New City programs will be required to identify and prioritize upgrades to local water and sanitary systems based on intensification development pressure, asset condition, and existing system vulnerabilities; and
- A growth financing mechanism, such as Development Charges, will be needed to support these programs.
Early findings from these studies indicate that water and wastewater system capacity is available to support significant increases in intensification in most areas of the City. The key reasons for this are as follows:
- Per capita water demands have been dropping steadily over the last 30 years;
- Redevelopment in many areas of the City provides opportunities to remove wet weather flow from the sanitary sewer system; for example, through elimination of existing foundation drain connections;
- On-site stormwater management provides opportunities to reduce flows to the City’s combined sewers, allowing capacity for future sanitary flows;
- Local watermain sizing is not typically governed by average daily water demand;
- Pipe sizing standards govern the sizing of the upstream sections of local sanitary networks.
Water and Wastewater Master Plans
Studies to support updated Water and Wastewater Master Plans are in progress to identify the major infrastructure projects needed to support growth to 2046 and beyond. These major projects will account for land use intensification, greenfield development on vacant urban lands in established areas, and any urban expansion lands approved by Council in February 2021.
Detailed models of the existing water distribution system and wastewater collection system have been improved, updated, and calibrated based on monitoring data to support development of the Water and Wastewater Master Plans.
Gross City-wide projections were approved by Council in May 2021. Detailed local projections are currently being developed, which consider greenfield development and intensification-based development to support preparation of the plans.
Stormwater Master Plan
An updated Stormwater Master Plan (SMP) is also an important aspect of the IMP update. Generally, major stormwater infrastructure required to support greenfield development will continue to be planned and implemented by the development industry, subject to City approval processes. The Stormwater Master Plan will include recommendations for City-wide studies and programs, processes, and policies required to ensure resilience of Stormwater Management (SWM) systems and protection of receiving watercourses. It will also establish high-level requirements for stormwater management in expansion areas, including on sites with Low Impact Development (LID). LID involves the management and reduction of runoff as close to the site as possible to better mitigate impacts on receiving watercourses, compared to conventional approaches which treat stormwater at downstream locations.
The SMP will include an overview of existing and future conditions, including constraints and opportunities associated with existing infrastructure and natural drainage systems. Future conditions will consider local climate projections. The SMP also presents the strategy for developing stormwater management retrofit plans in existing development areas.
Expansion to the City’s village boundaries are not being contemplated in the New Official Plan. As such, it is not anticipated that any new infrastructure projects to support village growth will be identified in the IMP. However, the IMP will provide a status report on village development and the supporting infrastructure projects that were identified in previous editions of the IMP. Private servicing issues in the rural area will also be reviewed.