Collingwood, along with many areas of the province, has been dealing with rain, freezing rain, snow and snow melt over the past week. Our hard-working crews have been out monitoring localized flooding across town and managing extraordinary flows in our wastewater treatment system. Our engineers are also updating our stormwater plans and projects to ensure our systems can handle the increasing intensity of storms and identify what must be accommodated in new developments.
“We do important work as a municipality and with our conservation authorities to address Collingwood’s water-related triple threats – rivers, stormwater and wave uprush,” says CAO Sonya Skinner.
Due to the recent localized flooding and wastewater system bypasses, staff will review actions needed to better prepare for poor weather and communicate effectively with residents and businesses.
With respect to rivers and stormwater, a study is nearing completion and a final report incorporating public input is the next step. The draft findings are on the Town’s Engage Collingwood page: https://engage.collingwood.ca/swmmp with the latest information in the Public Information Session (PIC) #2 materials. This study recommends immediate and longer-term work and potential sources of funds for each project.
“We do not like to see any flooding, though with certain storms beyond the 5-year average, we expect and plan for spills within the flood plain areas that are regulated by our Conservation Authorities,” says CAO Skinner. “One of the factors in flooding risk is the climate change impacts including larger storms.”
There also may be a perception of unfairness, as some people think that changes to stormwater runoff are caused by new developments. However, all major development proposals are required to complete a stormwater management report demonstrating how stormwater infrastructure will limit peak flows and meet water quality requirements. One may often see stormwater ponds or other options used for this in new developments. Further, new developments pay Development Charges, which pay for infrastructure expansion.
In 2025 the Town is kicking off work to expand the wastewater treatment plant. “While we are at about 80 percent capacity, our recent bypasses are not due to wastewater flows, they are due to the inflow of water into the wastewater drains. The amount of water flowing through the plant after significant rain can mount to more than double the capacity of the plant,” says Peggy Slama, Manager, Water and Wastewater. “A priority project for 2025 is to identify the largest sources of inflow and propose a plan to address them.”
“We understand there may be some confusion about why stormwater affects the wastewater treatment plant, causing a bypass, and some suggest that new developments are to blame. However, the additional flows are due to stormwater making its way into the sanitary system. Also, growth pays for growth; existing taxpayers do not pay for the expansion of our infrastructure to meet growth,” says CAO Skinner. “Council has been proactive in asking that our Stormwater Plans be updated with the best technology available, using the input of our residents to help identify their areas of concern, and considering climate change impacts. Staff also work with developers to ensure developments fulfill modern drainage requirements.”
Here are some FAQs to help residents understand our stormwater system and why bypasses occur at the Wastewater Treatment Plant during weather-related events:
Question: How does rain and snow melt affect the Wastewater Treatment Plant (WWTP)? / What causes a Bypass to happen?
Answer: During intense or long duration storms water can make its way into the wastewater sanitary system. This can happen at manholes, cracks in pipes, and if sump pumps and roof leaders are connected to the sanitary system. When the flows at the WWTP are in excess of what the plant can handle, wastewater overflows to the Bay.
Question: What is the difference between a partial bypass and a full bypass (overflow)?
Answer: When the Town refers to a partial bypass, that means all wastewater is receiving treatment, with part of the treatment process being bypassed. When the WWTP is fully bypassed, raw wastewater is diverted directly to the bay and does not receive treatment.
Question: Is there anything the Town can do to prevent this from happening?
Answer: The Town is currently performing an Inflow and Infiltration review to identify where stormwater is entering the wastewater sanitary system, so this can be addressed. An update of the Stormwater Master Plan is also nearing completion. These plans consider the current situation, and the most efficient projects to improve today and address the future. In 2025 the Town is also starting the process for a Wastewater Treatment Plant Expansion.
The photo is for illustrative purposes.
