A railyard and logistics centre Staged Master Drainage Plan (SMDP) outlines the stormwater management strategy for a 536‑hectare industrial development in southern Alberta. Prepared to meet strict local authority guidelines in a closed basin, the plan aims to manage post‑development runoff, protect retained Crown‑claimed wetlands, and integrate local and regional drainage infrastructure. The SMDP emphasizes adaptive management and long‑term monitoring to address uncertainties in groundwater–wetland interactions and ensure ongoing regulatory and environmental compliance. The site consists primarily of cultivated land with flat topography and numerous wetlands. Geotechnical and groundwater investigations identified variable till layers and shallow bedrock, with groundwater generally flowing toward wetlands and exhibiting seasonal fluctuations. These conditions informed the drainage design and wetland protection approach. Stormwater management is centered on nine wet stormwater management facilities (SWMFs) designed to provide sediment control and water quality treatment, exceeding the local authority requirement for 85% total suspended solids removal. Several facilities are positioned to support wetland hydrology and include provisions for direct pumping where required. A regional stormwater trunk system conveys controlled outflows to an open channel and is sized to accommodate both onsite and upstream catchments. Development is planned in six phases, with each phase extending the trunk system and constructing associated infrastructure. Due to the absence of feasible overland emergency spill routes, the trunk system is designed with increased capacity to manage extreme storm events. Hydrologic modeling using PCSWMM shows reduced infiltration and groundwater recharge and increased surface runoff following development. To mitigate impacts on wetland hydroperiods, adaptive management measures are recommended, including seasonal or year‑round pumping and potential supplemental groundwater baseflow.
