TRACK 2, DAY 2
Navigating Watershed Futures: Muskoka River Ecological Flow Assessment in a Changing Climate
Thursday, March 27, 2025 | 3:45 p.m. to 4:15 p.m. | Hall F
ABSTRACT
The District of Muskoka is working to improve the Muskoka River Watershed’s health. GHD worked with the District to develop a calibrated long-term, continuous hydrologic model of the watershed that incorporates its ecological structure and dynamics and characterises its functions.
The model was used to run various “what-if?” scenarios encompassing climate change, population growth, changes to wetlands, and deforestation. The scenario results were used to further understand the watershed processes and potential impacts to the flow regime.
This presentation will focus on the ecological flow assessment, which was performed using the MNRF Aquatic Ecosystem Assessment for Rivers to evaluate the baseline and potential alterations for two ecological flows: subsistence and channel forming flows.
These flows are indicators of the “lower” hydrological regimes of a river as compared to peak and riparian flows and they are directly tied to aquatic ecosystem function. Channel forming flows surpass the threshold of sediment erosion and are important to fish habitat since they produce and maintain natural channel structures.
Study results indicated that the subsistence flows in the watershed are sensitive to climate change. Channel forming flows were likewise sensitive to climate change, particularly with timing and duration.
An increase in channel forming flows which may lead to increased erosion, and a shift to earlier occurrences is seen in the majority of the climate scenarios modelled.
ABOUT THE PRESENTER
Lisa Bowering (GHD)
Lisa is a water resources engineer at GHD in Waterloo with over 11 years of experience. Lisa’s expertise encompasses a wide range of technical skills, including hydraulic and hydrologic modelling, stormwater management design, climate change risk assessment, and Geographic Information Systems (GIS).
Throughout her career, Lisa has contributed to numerous projects involving natural channel design, floodplain mapping, hydro climate data analysis, the development of Intensity-Duration-Frequency (IDF) curves including climate change analysis, and projects relating to infrastructure and climate change.
Her contributions to the field are further highlighted by her authorship and co-authorship of peer-reviewed scientific papers on the impacts of climate change on municipal infrastructure. Additionally, she serves as a referee for the Journal of Flood Risk Management and Urban Water.