Previous studies have reported variable outflow nutrient concentrations at peat harvesting operations across Canada. During opening and extraction phases, major changes that can occur to peatland hydrology, physicochemical and nutrient export, and the impact on water quality at each phase, have not been well studied in relation to geology and climate across the Canadian boreal. Understanding the influence of hydrological connectivity, depth of ditching into mineral versus organic substrate, and peat harvesting phase on nutrient availability is crucial to ascertain the variability in exported nutrient concentrations and potential downstream eutrophication risk. Water level, flow, ice and aeration depth, electrical conductivity, and pH were measured at harvest fields and outflows in natural, opened, and extracted peatlands located in the sub-humid, glaciated, boreal region of Alberta, Canada. Dissolved and particulate nitrogen and phosphorus in surface water, groundwater, and outflows were assessed monthly from March through October in 2019 and 2021. Harvesting activities encouraged ice formation and altered the outflow volume and timing. Electrical conductivity and pH values were elevated in water from mineral ditches compared to natural peatland drainage waters. Ammonium and soluble reactive phosphorus (SRP) concentrations were higher in extracted surface peat, but values decreased in the mineral ditch outflow. Increased flow allowed beavers to establish a dam at the harvesting operation outflow. Downstream of the dam, ammonium and SRP concentrations rose above peat field outflow levels. Harvesting alters hydrological connectivity and peat nutrient transformations; however, ditch substrate and beaver activity may control final outflow biogeochemistry of carbon, nitrogen, and phosphorous.