Town of Tecumseh Storm Drainage Master Plan

In September of 2016, the Town of Tecumseh experienced significant flooding due to a 100 year storm event that overwhelmed the existing storm sewer and pumping stations. The Insurance Bureau of Canada estimated losses for the flooding at approximately $145-million. In response to this event, the town will conduct a vulnerability assessment of the current storm drainage network, including eight pump stations, the storm sewer system and the overland flow system. The local Essex Region Conservation Authority is supporting the study, and it is a municipal strategic priority to update the existing storm infrastructure where needed to ensure an adequate level of service to residents.The focus of the storm drainage Master Plan study will be on the most populated section of the town (approximately 1,282 hectares). The first phase of the study will include a Public Information Centre (PIC) session for local residents. This will kick-start the development of one and two dimensional models of the existing drainage system, including storm sewers, municipal drains and an overland roadway network under a range of storm scenarios. This existing conditions model will review the current level of service of each system and identify any constraints. Based on rainfall data collected during the storm event, a subsequent simulation of the 2016 event under existing conditions will qualify model results. A future conditions model will also assess the vulnerability of service areas under climate change (assuming a 20% increase in precipitation), presenting storm sewer improvement options and potential increases in levels of municipal services. The second phase of the project returns to local residents with the proposed remedial flooding solution designs, and the latter PIC session informs the final recommendations to the Town`s council.The project will follow the requirements of a Municipal Class Environmental Assessment (EA) study. This will include coordination with agency stakeholders and First Nations, posting of study information and project updates on the Town website, a notice of commencement to residents and local agencies, meetings to receive input on recommended solutions, and a notice of completion of the initiative. Specific deliverables of the study will include the review of low lying areas for attenuation of runoff volume from large storm events and solutions to address limitations in overland conveyance and excessive surface ponding. Pumping station upgrades, storm sewer improvements, major system storage and conveyance upgrades and consideration of green infrastructure as potential solutions for lot-level volumetric controls will also form essential elements of the study. The master plan will form a key component of the Town’s broader program of sustainable infrastructure solutions that contribute to reducing the risks and impacts of flooding.