Wainwright Siphon Assisted and Green Power Stormwater Management Project

In order to more effectively and sustainably control the stormwater that drains into its terminal water body, the Town of Wainwright will implement a series of engineered wetland system measures that will better treat and manage the quantity and quality of stormwater runoff to the Battle River. The plans, policies and programs that align with the Town’s Municipal Development Plan, particularly as they relate to the protection of the landscape from agricultural operations and urban development, support the main objective of this initiative. The project will include a series of phases that will enhance the existing drainage features of the landscape. With the necessary municipal, provincial and private landowner right of access and approvals, initial downstream segregation and bypass measures will separate the eastern and western portions of the watershed through independent paths. That is, rather than have all the stormwater flow to the pre-terminal Bushy Head Lake, which already receives effluent from a neighbouring wastewater lagoon, this re-routing will divert the majority of the stormwater to a newly formed attenuation pond (Gold Quarter Pond) before eventual discharge to the Battle River. Floating Treatment Wetlands (FTWs) in the Gold Quarter Pond will balance nutrient management with variable stormwater input, as there will be no physical contact between the FTW roots and the pond’s soil. Construction will then move upstream, where a six-kilometre gravity controlled pipeline will effectively allow low-lying upstream land to release trapped water for the reconstitution of adjacent wetlands. Comparison of performance before and after modifications through volumetric and water quality sampling will help assess the long term ecological health of the system. The overall project design will reduce the aquatic stress in the terminal Battle River with increased capacity for attenuation and greater control over drainage and flow of stormwater runoff. The stream segregation measure and added Gold Quarter Pond holding capacity (750,000 m3/year), will reduce Total Suspended Solids by over 90%, Ammonia and Nitrate by approximately 90%, Chloride by 50%, Total Phosphorus by 65%, and biological oxygen demand by 75% in the Battle River. The system design may also allow for part of the Gold Quarter Pond attenuated stormwater to blend back into Bushy Head Lake to further reduce terminal contaminant concentrations. The total storage capacity of the system will far exceed the volume of runoff generated by the 90th percentile rainfall event by 3.3M m3. The gravity-controlled weir will contribute over 500,000 m3 of capacity to the system, while also creating an additional 750,000 m2 of natural wetland. In addition, the topography of the landscape will provide the relative elevations to drive a micro-power plant that will generate the electricity required to siphon 5 million m3 of stormwater to the new wetlands and downstream system every year. Relative to a grid-based system, this hydro-generated siphon system will reduce 258 tonnes of C02e/year. The knowledge value of this initiative lies in its integration of upstream and downstream measures with an energy efficient pumping system that ultimately gives a municipality more control over its natural assets. (Project description from original funding application)