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Asadzadeh M.,National Water Research Institute | Asadzadeh M.,University of Manitoba | Leon L.,National Water Research Institute | McCrimmon C.,National Water Research Institute | And 5 more authors.
Journal of Great Lakes Research | Year: 2015

Continuous daily simulation of watershed-derived nutrient and sediment loads is required to estimate nearshore water quality in Lake Ontario and the impact of watershed beneficial management practices on lake water quality. In this study, the Soil and Water Assessment Tool (SWAT) is used to build watershed models that incorporate detailed information about representative land operation activities applicable to agricultural watersheds in Southern Ontario. SWAT is calibrated in a multi-objective simulation-optimization framework for the Rouge River watershed with a relatively high spatial resolution monitoring network. These parameters were directly applied to the model for an adjacent watershed, Duffins Creek. The model performed satisfactorily in both watersheds in terms of water balance and temporal, vertical, and spatial redistribution of water. Assessment of the model performance metrics shows a good agreement in the frequency distribution of measured and simulated water quality constituents. Both watersheds are experiencing rapid urbanization, so decision makers in the region may find the developed model useful to analyze the impact of future landuse and operation changes on watershed-derived sediment and nutrients to be delivered into Lake Ontario. © 2015 Published by Elsevier B.V. Source

Makarewicz J.C.,New York University | Booty W.G.,National Water Research Institute | Bowen G.S.,Toronto and Region Conservation Authority
Journal of Great Lakes Research | Year: 2012

Tributary phosphorus (P) loading was estimated for 145 Canadian and American streams entering Lake Ontario and was compared with historical P loads of the Niagara River. The 145 Lake Ontario tributaries contributed 2606. mT/year of P, with the U.S. tributaries contributing 1411. mT/year and the Canadian tributaries contributing 1195. mT/year. In New York, the largest tributary sources of total phosphorus (TP) were from the Genesee River (417. mT/year), followed by the Oswego River (336. mT/year) and the Black River (135. mT/year). In Ontario, the largest tributary sources of TP were from the Trent River (200. mT/year), the Humber River (93.0. mT/year), and the Welland Canal (80.8. mT/year). Phosphorus loading from both Canadian and American wastewater treatment plants was 781. mT in 2008. The total P load of tributaries (2606. mT/year) to Lake Ontario was 234% higher than that of wastewater treatment plants and was 67.5% of the 1982 Niagara River P load and 50.3 to 70.6% of the 1999 and 2004 Niagara River P loads. While the P load from the Niagara River connecting channel is important to the overall trophic status of the offshore of Lake Ontario, the impact of tributaries on water chemistry and ecology of the nearshore and embayments of Lake Ontario is potentially great and is being increasingly recognized as a driver of nearshore conditions. © 2012 Elsevier B.V. Source

Young D.,Toronto and Region Conservation Authority
Environmental Connection Conference 2015 | Year: 2015

Introduction : Infiltration practices are an integral part of progressive approaches to stormwater management. These practices help to reduce the volume of urban runoff discharged to watercourses thereby minimizing flood risk and preventing alterations to the stream flow regime and channel form. They help to maintain groundwater levels and sustain stream flows during dry periods. They also reduce pollutant loading to receiving watercourses by reducing runoff volume and retaining or breaking down pollutants in the engineered structures and underlying native soil. They can be designed for application at the ground surface (e.g., permeable pavement, bioretention, infiltration basins) or below ground (e.g., soakaways, infiltration trenches and chambers, and exfiltration sewer systems). An advantage of underground infiltration technologies is that they can be located below parking lots, roads, parkland or other landscaped areas. In densely developed urban areas, where the value of land is very high, this often makes them preferable to surface practices. Despite their advantages, designers are often reluctant to recommend the application of infiltration practices on fine textured soils due to their limited permeability and concerns over the required size of facilities. Since most of the designated urban growth areas in the Greater Toronto Area and southern Ontario are located on fine-textured glacial till soils, there is considerable interest in how effective infiltration practices are in such contexts. This study helps to address this knowledge gap by evaluating the effectiveness of three underground stormwater infiltration systems constructed over fine-textured glacial till soils draining roof runoff from industrial/commercial developments located in the Greater Toronto Area. Source

Booty W.G.,National Water Research Institute | Wong I.,National Water Research Institute | Bowen G.S.,Toronto and Region Conservation Authority | Fong P.,National Water Research Institute | And 2 more authors.
Water Quality Research Journal of Canada | Year: 2014

Integrated watershed-lake modelling requires high quality data for calibration and validation. The two-phase loading estimate approach presented here provides a more confident estimate of nutrient loads for these models. Phase 1 establishes the initial range of the loading estimates using averaging algorithms, ratio estimators, event mean concentration (EMC) and regression-based methods. For Duffins Creek outlet, the 2007, 2008 and 2009 ranges are 6.2-30, 22.3-78 and 19.5-242 tonnes of total phosphorus (TP), respectively. After combining the Beale ratio estimator and the regressionbased methods in Phase 2, the 2007, 2008 and 2009 ranges are reduced to 13-17, 57-73 and 69-92 tonnes TP, respectively. The reduction represents the 0 and 28.07% upper bound bias of the regression-based method. Applying this information to the regression-based methods, daily and monthly ranges with a lower bound with no adjustment and with upper bound as 1.2807 times the regression-based TP load estimates are established. These loads are then used in integrated watershed-lake model calibration and validation to improve the model predictions. © IWA Publishing 2014. Source

Bazinet N.L.,Ontario Ministry of the Environment and Energy | Gilbert B.M.,Ontario Ministry of the Environment and Energy | Wallace A.M.,Toronto and Region Conservation Authority
Water Quality Research Journal of Canada | Year: 2010

Benthic invertebrate communities were compared in several watersheds within an urban basin and an urbanizing basin in southern Ontario, Canada. The urban watersheds of the Lake Ontario basin and the urbanizing watersheds within the Lake Simcoe basin share similar geologies, soils, and climates, but differ in the stage of urban development within these two basins. Correspondence analysis showed that invertebrate populations formed distinct groups split between these two basins owing to intense urban development in the Lake Ontario watersheds versus the agricultural nature of the Lake Simcoe basin. Canonical correspondence analysis ordinations indicated that the major environmental gradients were related to urban land cover (imperviousness), chloride, nitrates and stream order factors. Urban land cover and chloride were most strongly associated with the first axis. The typical logarithmic relationship between urban land cover and benthos found in other studies was not evident in this study. Rather, 9 of the 12 metrics tested had significant linear relationships with urban land cover. The Hilsenhoff Family Biotic Index and percent Oligochaeta metrics showed the strongest positive linear relationships with urban land cover. Pollution sensitive groups (Ephemeroptera, Plecoptera, and Trichoptera) along with richness and diversity measures decreased with increasing urbanization. © 2010, CAWQ. Source

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