2023 STEP WEBINAR SERIES
Presenters: Colin Dunlop & Alex Fitzgerald (Credit Valley Conservation)
It is important to assess how bioretention performance is affected during the winter when infiltration may be impacted by freezing temperatures.
Soil moisture is primarily influenced by runoff, precipitation, and infiltration in swales. Collection of continuous soil moisture data may provide insight into bioretention performance year-round.
This project assesses how bioretention swales at the IMAX corporate office perform with the use of soil moisture data, and how they perform during the winter months. Findings from this will help inform future LID design and operation and maintenance.
Upstream and downstream soil moisture data from two swales was first analyzed on a precipitation event basis during non-winter months of different sizes, intensities, and temperatures to develop a baseline understanding of performance.
Winter events were then analyzed in comparison to understand how the performance differs from non-winter condition events.
The results found that both swales were close to meeting their design criteria. One swale had a catchment larger than originally designed and did not perform as well as the other. Winter data suggests that snow storage may be impacting infiltration in the swales.
When the temperatures rose above freezing, the soil moisture response would quickly return to normal, allowing for performance assessments to occur year-round. This can help inform if the swale is meeting its design criteria or of any maintenance needs that need to be addressed.
Learn more about the 2023 STEP Webinar Series.
Colin Dunlop is a Water resources technician with the water and climate change science division at Credit Valley Conservation (CVC). He started at CVC in 2019 as an assistant before becoming full-time in 2021. He completed his undergraduate at McMaster University for Earth and Environmental Science in 2020 and a Graduate Certificate in Environmental Management and Assessment at Niagara College in 2021.
Alex Fitzgerald is a Water Resources Technician at Credit Valley Conservation (CVC). He splits his time between working on LID monitoring, watershed modelling, and climate change adaptation. Prior to working at CVC, he worked with the Canadian Environmental Assessment Agency. He has a Master of Science with McMaster University, where he focused on groundwater-surface water interaction.