Saunders Lake Stormwater Impact Evaluation

Leduc County, AB

Altalink is interested in constructing a new substation in close proximity to Saunders Lake near the City of Leduc. Before proceeding with construction, they selected three possible sites and engaged ISL to complete a Phase 1 Stormwater Impact Evaluation to determine what stormwater impacts might result from each of the three sites.

Document Review

To produce the high level document needed to evaluate each site, ISL reviewed all the regional and local stormwater management guidelines and plans, including the delineation of catchment areas and the site grading standards. We also conducted a detailed assessment of pre- and post-development release rates, downstream impacts and surface flow data.


Using this information, our team created a detailed surface model, and each scenario for each site was evaluated using XP-SWMM (2D Add-on) software. Peak site discharge rates were applied downstream of each potential site for multiple flowpaths.

Regulatory Approvals

Many high-level conversations were conducted with Alberta Environment in order to be proactive in terms of the stormwater management process and the level of regulatory risk outside of local municipalities.

Final Report

A Stormwater Management Report was compiled for Altalink's use. The report offered an unbiased presentation of potential stormwater impacts for each site, as well as recommendations and suggestions for discussion when selecting the final construction site. The report will act as a baseline for mitigation recommendations once the site has been chosen.

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