Municipal Natural Assets Initiative

The magnitude of the loss in attenuation and the consequences of increased flood flows on downstream neighbourhoods and infrastructure requires a hydrodynamic model of the entire Millstone River, which was beyond the scope of this study. [...] The northern boundary of the area of interest is contiguous to the Millstone River and the western boundary follows the Nanaimo Parkway, where highway 19 bypasses the city. [...] The city is interested in understanding, quantifying and maximizing the municipal services from the BMCA in order to improve 4. What is the value of the BMCA in terms of assuring downstream water quality? [...] Reference documents were used to compile the hydraulic information associated with the BMCA, and to understand the relationship of the marshes to the Millstone River. [...] Thus, the marsh has a regulating effect, decreasing the flows during the rising limb of the hydrograph, reducing the peak flow and contributing to the flow during the falling limb.” The estimated attenuation of the flood flow in the Millstone River associated with the storage of flood water from the river to the elevation of 58.37 meters above sea level (masl) was approximately 20 per cent - 105 m