Mountview Stormwater Management Design

2020 – 2021 (Ongoing) | Grande Prairie, AB

The City of Grande Prairie Mountview residential neighbourhood (located near 97 Street and 111 Avenue) is often subject to flooding during heavy rainfall and saturated ground conditions. The Mountview area is a mature neighbourhood built to old drainage standards. To address the old drainage standards and flooding, the City of Grande Prairie partnered with McElhanney to develop a robust and economical drainage solution. To determine the optimal design, an in-depth understanding of the overland flooding mechanisms was required. To accomplish this task, McElhanney developed a 1D-2D hydrologic and hydraulic model to review overland flow paths, ponding locations, and ponding depths; and assessed the proposed drainage strategy. The analysis revealed that the surface ponding within the Mountview neighbourhood was due to two constraints: a lack of inlet capacity and a lack of downstream storm sewer capacity. A design was subsequently established to add upstream stormwater storage to reduce flows and to increase inlet capacity at low points. A review of the existing sewer condition also revealed a downstream sewer blockage due to asset failures. As soon as the blockage was noted, McElhanney and the City worked quickly to develop a design and tender to have the blockage removed as soon as possible. Provincial economic stimulus funding was applied to support this project; therefore, the project required an accelerated schedule through the design and tender phases to accommodate funding requirements. McElhanney and the City are currently on track to meet all schedule requirements and have the improvements in place by the end of 2021.

The required engineering services included, storm water modeling and assessment, detailed design, tender preparation, construction inspection services, and post construction and warranty services.