PROJECT SUMMARY

The Town of New Hamburg is located along the Nith River and is one of 27 municipal flood damage centres in the Grand River Conservation Authority’s (GRCA’s) jurisdiction. The Town was established and developed in the Nith River floodplain and is subject to routine nuisance flooding; in addition to significant flooding events in 1975, 2008, and most recently in February 2018 and January 2020. Matrix was retained to estimate average annual flood damage costs associated with existing flooding, develop and evaluate potential mitigation strategies, and provide support for two Public Information Centres (PICs).

Matrix’s scope of work included:

• Reviewing background information, including streamflow monitoring data, previous flooding reports, and previously completed flood damage estimates and flood mitigation options.
• Completing flood damage estimates to provide a basis for comparing return-on investment (ROI) for potential flood mitigation options.
• Developing a long-list of flood mitigation options and screening criteria to identify a short-list of mitigation options to carry forward.
• Completing hydraulic modelling, cost estimates, and flood damage estimates for short-listed alternatives.
• Attending PICs to share findings with and solicit feedback from the public.

PROJECT OUTCOME

Matrix provided GRCA with a high-level evaluation of potential mitigation options to reduce flooding in New Hamburg based on estimated flood damages and ROI. A prioritization plan was also provided to allow GRCA to identify and evaluate potential mitigation projects that warrant further study as part of future Environmental Assessment projects.