Client: City of Brantford
Location: Brantford, Ontario
Year Completed: 2019
J.L. Richards & Associates Limited (JLR) provided prime consulting multidisciplinary services for a new administration building and vehicle storage garage in Brantford, Ontario. The stormwater management (SWM) component was led by the JLR water resources team.
The project required the design of a SWM system in support of the new building and parking area. The SWM system was developed to account for site constraints while achieving the required stormwater discharge criteria. The site was constrained by being next to the existing operational water treatment plant and a heritage building limiting the footprint of any potential SWM facilities. In addition, the site was located within Brantford’s source water protection zone and within a flood zone which again restricted options for stormwater management. Any facilities which were to be incorporated into the site could not become inundated in a flood event while the site also had to meet the enhanced protection level and mitigate any increase in runoff which would exacerbate flood conditions. The site had peat soils and extensive underground infrastructure.
Working as a multidisciplinary team it was found that solutions to some aspects of the project, such as building foundation requirements, were mutually beneficial to multiple aspects of the project including the SWM. As part of the project, and to remedy the poor geotechnical conditions, the majority of native material was removed and replaced with material better suited to a grade raise allowing the regarded surface to be removed from the floodplain. Based on hydraulic conductivity testing completed by the geotechnical engineer, the optimum location of two infiltration galleries was identified and sized to meet the enhanced protection level.
A proprietary underground storage and infiltration system was specified in the design as this was found to keep the footprint of the infiltration gallery smaller while maximizing capacity, ease of installation, and reducing maintenance requirements in the long term.