Since phase 1 of the public consultation, the project team has undertaken a number of technical studies that have – along with feedback from the campus community – informed the emerging directions for rainwater management at UBC.
The technical analysis undertaken by Urban Systems to inform emerging directions for rainwater management on campus included:
- Geo-technical soils analysis of the campus to determine soil permeability
- Hydrologic modelling to simulate rain water rates and effectiveness of potential controls, including impacts to the existing Pond
- Potential future climate impacts, such as increases in precipitation intensities, for climate adaptation planning
The Main Campus has an established storm sewer system that ultimately drains to an existing pond located in the south east corner of the campus. The existing storm sewer system has a history of flooding at some locations during heavy rainfall; increased runoff rates and volumes pose a concern of increased flood risk with the Main Campus area. There are also a number of planned projects that will result in site transformation and planning to manage future rainwater.
Analysis demonstrates that effective site controls that utilize pervious areas for rainwater management can be significantly beneficial in managing runoff while significantly reducing costs of storm sewer replacement that would otherwise be required. For the main campus in particular, this is very meaningful to manage flood risk. If successfully done, investing in site controls can have a number of benefits including improved ecological conditions and cost savings from reduced infrastructure.
Work is underway to inform general maintenance requirements of the existing grey infrastructure to ensure its viability to support the pond over time. UBC is also conducting a topographical survey to further inform flood path risks and proposed measures at this stage.
The innovation precinct is largely undeveloped and was a former gravel mining operation. As part of the IRMP, a soil survey was conducted which identified a relatively thin layer of lower highly permeable soils on top of an aquifer. Highly permeability in this area offers several options for managing rainwater.
Given the rapid infiltration zone, several options to manage rainwater could be implemented. These include:
- Centralized stormwater management facilities, with cost, maintenance and space utilization benefits, or the implementation of smaller, highly distributed facilities.
- Opportunities for disposal and temporary storage with centralized stormwater facilities. The potential for a relatively pipe free Innovation Precinct provided there is acceptance for overland flow paths to a centralized storage and disposal facility.
- Rehabilitation or relocation of Lot H infiltration ditch with care to preserve and protect Spadefoot Toad habitat.
The eventual approach for managing rainwater at the Innovation Precinct will be further informed by the Innovation Precinct project. UBC is also conducting a topographical survey to further inform flood path risks and proposed measures at this stage.
Last reviewed 10/31/2016 10:09:34 AM