UBC South Campus Stormwater Detention Facility
Creators: name: Gerard, Emma
name: Bae, Do Youl
name: Neyshaboori, Sadaf
name: Granger, Brody
name: Kim, Kelim
Publisher: name: The University of British Columbia
Year: 2017

description: Point Grey Consultants Ltd. was retained by Doug Doyle, Associate Director of Municipal Engineering for UBC Campus and Community Planning to design a stormwater management system for the UBC South Campus. The system is designed to provide stormwater detention for up to a 100 year storm, with a storage capacity of 4150 m³. This is achieved using an underground detention tank overlaid by a bio-retention pond which allows ponding of water. Pollution removal occurs as the bio-retention pond infiltrates stormwater flows up to a 2 year storm. The underground detention tank is 0.61 m high by 70 m long by 30 m wide and is to be located on the north corner of the intersection of Wesbrook Mall and SW Marine Drive. The overlaid bio-retention pond of the same area as the tank is to be constructed with 1 m of engineered soils with an infiltration rate of 43 mm/hr and planted with vegetation. A dyke surrounding the bio-retention pond will allow ponding of water up to 1.4m. Water that currently flows through the 1.05 m diameter storm main will be re-routed into a 1.05m culvert which discharges into the bio-retention pond. This water enters a central trough that runs the length of the bio-retention pond and spills onto adjacent rock that slows and distributes the water. Overflow pipes located 0.5 m above the surface of the bio-retention pond discharge water into the underground tank when ponding exceeds this level. A new by-pass pipe at 105 m upstream of the tank along the road will connect the existing stormwater main to the detention tank. An orifice outlet releases water at maximum rate of 261 L/s and discharges into the existing 1.2 m storm main. Throughout the design process, Point Grey Consulting has used the United States Environmental Protection Agency’s Storm Water Management Modelling (US EPA SWMM) software. Numerical modelling of 100 year storms before and after the addition of this detention facility show that local flooding has been eliminated. The final design report contains the detailed design description of the detention tank and the bioretention pond. This includes tank, bio-retention pond, and bypass pipe locations and dimensions shown in AutoCAD and Sketchup drawings. A finalized cost estimate, work schedule, detailed construction activities along with specific site constraints is presented. Finally, recommendations are given for further improvement of the design. Disclaimer: “UBC SEEDS provides students with the opportunity to share the findings of their studies, as well as their opinions, conclusions and recommendations with the UBC community. The reader should bear in mind that this is a student project/report and is not an official document of UBC. Furthermore readers should bear in mind that these reports may not reflect the current status of activities at UBC. We urge you to contact the research persons mentioned in a report or the SEEDS Coordinator about the current status of the subject matter of a project/report.”