If the design objective is to meet and provide peak flow control for storm events, it is necessary to plan beyond the 1:100-year peak flow, and instead plan for the new norm of a 1:1000-year flood event. Planning for the appropriate peak flow is crucial to building climate resilience and meeting the demand over the full lifecycle of the infrastructure. If an inadequate peak flow formula is used it could result in significant additional costs to the City if it has to repair or tear up failing infrastructure to rebuild and increase capacity before it has reached its end-life. “Even a 1000-year return period has a 5% risk of being equalled or exceeded in a 50-year period.”
The Report indicates that “the anticipated influence of climate change on precipitation is steeped in uncertainty with future projections ranging from a minimal increase to almost a 250% increase”, and yet the stormwater planning only ranges from a 1:5 to a 1:100-year flood event. The Report admits that “this range represents a significant challenge to the municipality to understand and integrate into its planning decision making process”.
Climate Change is projected to have long-term and ever-increasing effects on communities and the environment. It is encouraging to hear that data gaps in the vulnerability assessment for the City of Greater Sudbury’s (CGS) drainage related infrastructure are being addressed to prepare for the predicted increases in the severity and frequency of extreme weather events associated with climate change.
It is also important to emphasize the importance of planning for a warming climate by building resilience into whichever alternative/s are chosen. In this vein, planning should be based on at least a 1:200-year storm event, and preferably a 1:1000-year flood event for true resilience to climate change.
These Public Information Centre panels are very high level, so at this time there isn’t too much to comment on; however, it is important to consider the Chelmsford Wastewater Treatment Facility in this assessment.
Watershed and subwatershed studies should include water quality and water quantity considerations to help maintain and enhance natural freshwater systems, including fisheries and aquatic habitat. These considerations should be guided by commonly accepted and held principles, including an ecosystem-based approach, a landscape-based analysis, cumulative effects, the precautionary approach, adaptive management, and sustainable development.
What are the goals and objectives of this study? There is very little information about the subwatershed study, but instead appears to be primarily designed to manage stormwater run-off to prevent flooding and development impacts.
As part of the Lower Vermilion Source Water Quality Monitoring Project, funded through a 3-year Ontario Trillium Foundation grant, Carrie Strangway completed her Master’s Thesis in partial fulfillment of the requirements for a degree of Master of Science in the Faculty of Science, Applied Bioscience, University of Ontario Institute of Technology. What follows is Carrie’s published Thesis:
Abstract The Vermilion River and major tributaries (VRMT) are located in the Vermilion watershed (4272 km2) in north-central Ontario, Canada. This watershed not only is dominated by natural land-cover but also has a legacy of mining and other development activities. The VRMT receive various point (e.g., sewage effluent) and non-point (e.g., mining activity runoff) inputs, in addition to flow regulation features.
Further development in the Vermilion watershed has been proposed, raising concerns about cumulative impacts to ecosystem health in the VRMT. Due to the lack of historical assessments on riverine-health in the VRMT, a comprehensive suite of water quality parameters was collected monthly at 28 sites during the ice-free period of 2013 and 2014. Canadian water quality guidelines and objectives were not met by an assortment of water quality parameters, including nutrients and metals. This demonstrates that the VRMT is an impacted system with several pollution hotspots, particularly downstream of wastewater treatment facilities. Water quality throughout the river system appeared to be influenced by three distinct land-cover categories: forest, barren, and agriculture.
Three spatial pathway models (geographical, topographical, and river network) were employed to assess the complex interactions between spatial pathways, stressors, and water quality condition. Topographical landscape analyses were performed at five different scales, where the strongest relationships between water quality and land-use occurred at the catchment scale. Sites on the main stem of Junction Creek, a tributary impacted by industrial and urban development, had above average concentrations for the majority of water quality parameters measured, including metals and nitrogen. The river network pathway (i.e., asymmetric eigenvector map (AEM)) and topographical feature (i.e., catchment land-use) models explained most of the variation in water quality (62.2%), indicating that they may be useful tools in assessing the spatial determinants of water quality decline. Read more →
As part of the Lower Vermilion Source Water Quality Monitoring Project, funded through a 3-year Ontario Trillium Foundation grant, Carrie Strangway completed her Master’s Thesis in partial fulfillment of the requirements for a degree of Master of Science in the Faculty of Science, Applied Bioscience, University of Ontario Institute of Technology. What follows is a poster of her more detailed manuscript, which will be published shortly:
The Vermilion River and major tributaries (VRMT) receive various point and non-point inputs, in addition to several flow regulation features, along their continuum. Further development in the Vermilion watershed has been proposed, raising concerns about cumulative impacts to the ecological health of the VRMT. To assess the current state of riverine health, water quality metrics were monitored monthly at twenty-eight sites during the ice-free period of 2013 and 2014. Generation of landscape-scale data revealed a broad range of land-cover and road density in the watershed at differing landscape-scales. Sites on the main-stem of the Junction tributary had above average concentrations for the majority of water quality parameters measured, specifically, sites within Copper Cliff Creek and Junction Creek (i.e. CC- 12 and JUN-13) were the most impacted. The river network pathway (i.e. asymmetric eigenvector map (AEM) eigenfunctions) and topographical features (i.e. catchment land-use) explained most of the variation in water quality (62.2%), thus both proved to be useful spatial determinates of deteriorating water quality.Spatial-determinants-of-deteriorating-water-quality-in-the-Vermilion
VRS is recommending that a portion of the funding be assigned to a Master Watershed Study for the Vermilion River Watershed. This study would take a big picture perspective, and consider the cumulative effects that development, stormwater runoff, and wastewater and mining effluent are having on the Vermilion River. This would better inform potential mitigation measures required for the subwatersheds contained within it.