Toronto and Region Conservation Authority

Toronto, Canada

Toronto and Region Conservation Authority

Toronto, Canada
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Walsh C.J.,University of Melbourne | Booth D.B.,University of California at Santa Barbara | Burns M.J.,University of Melbourne | Fletcher T.D.,University of Melbourne | And 6 more authors.
Freshwater Science | Year: 2016

Urban stormwater runoff is a critical source of degradation to stream ecosystems globally. Despite broad appreciation by stream ecologists of negative effects of stormwater runoff, stormwater management objectives still typically center on flood and pollution mitigation without an explicit focus on altered hydrology. Resulting management approaches are unlikely to protect the ecological structure and function of streams adequately. We present critical elements of stormwater management necessary for protecting stream ecosystems through 5 principles intended to be broadly applicable to all urban landscapes that drain to a receiving stream: 1) the ecosystems to be protected and a target ecological state should be explicitly identified; 2) the postdevelopment balance of evapotranspiration, stream flow, and infiltration should mimic the predevelopment balance, which typically requires keeping significant runoff volume from reaching the stream; 3) stormwater control measures (SCMs) should deliver flow regimes that mimic the predevelopment regime in quality and quantity; 4) SCMs should have capacity to store rain events for all storms that would not have produced widespread surface runoff in a predevelopment state, thereby avoiDing increased frequency of disturbance to biota; and 5) SCMs should be applied to all impervious surfaces in the catchment of the target stream. These principles present a range of technical and social challenges. Existing infrastructural, institutional, or governance contexts often prevent application of the principles to the degree necessary to achieve effective protection or restoration but significant potential exists for multiple co-benefits from SCM technologies (e.g., water supply and climate-change adaptation) that may remove barriers to implementation. Our set of ideal principles for stream protection is intended as a guide for innovators who seek to develop new approaches to stormwater management rather than accept seemingly insurmountable historical constraints, which guarantee future, ongoing degradation. © 2016 by The Society for Freshwater Science.

News Article | February 15, 2017

Editors Note: There are two photos associated with this press release. Senior levels of government continue to overlook the many benefits of investing in living green infrastructure such as urban forests, green roofs, green walls, and bioswales when making multi-billion dollar infrastructure decisions. Join us and shape a healthier and more resilient future at the Grey to Green Conference: Quantifying Green Infrastructure from May 8-10, 2017 in Toronto, Ontario, Canada. Now in its 5th year, Grey to Green will feature a Public Forum on May 8th to discuss barriers and opportunities to advance green infrastructure from a variety of professional perspectives. The Forum includes Jennifer Keesmaat, Chief Planner, City of Toronto; Deborah Martin-Downs, CAO, Credit Valley Conservation; Steven Peck, Founder and President, Green Roofs for Healthy Cities; and Scott Torrance, Practice Leader, Scott Torrance Landscape Architect. "Quantifying the biophysical, social and economic benefits of green infrastructure is essential to support better design practice and policies for investing in, and protecting, green infrastructure assets," said Steven W. Peck, GRP, and Founder of Green Roofs for Healthy Cities. "A lot of progress made on this front in the past year, which we plan to highlight at Grey to Green," he added. Grey to Green will attract more than 300 architects, landscape architects, policy makers, manufacturers, growers, landscapers, and other green infrastructure professionals to discuss the benefits, growth and tangible effects of the green infrastructure industry. More than 50 expert speakers on a wide variety of topics will present on May 9th their latest work on Natural Capital, Green Infrastructure Asset Management, Stormwater Policy Best Practices, Health Impacts of Green Infrastructure, and Green Infrastructure Design Valuation. Expert speakers include: Grey to Green also includes a trade show and exceptional networking. Most professional training opportunities are paired with tours and include Low Impact Development, Rooftop Agriculture, New Lighting Technologies for Indoor Vegetable and Medical Crop Production and Living Walls, Green Walls 101: Systems Overview & Design, and Integrated Water Management for Buildings and Sites. Presented by Green Roofs for Healthy Cities, the Green Infrastructure Foundation, in partnership with the City of Toronto. Proud sponsors include: Toronto and Region Conservation Authority; Live Green Toronto; DeepRoot; Green Infrastructure Ontario Coalition; Credit Valley Conservation; LiveRoof; Ginkgo Sustainability; Gro-Bark; TD Bank Group; Construction Links Media; Renew Magazine; Water Canada; Ontario Association of Landscape Architects; Ontario Parks Association; Ryerson University; Landscape Ontario;; Carrot Common; and Ryerson University Urban Water. Early bird rates end March 10, 2017. Student pricing is available. To register visit, For media passes please contact Kara Orr at Green Roofs for Healthy Cities' mission is to develop and protect the market by increasing the awareness of the economic, social and environmental benefits of green roofs, green walls, and other forms of living architecture. The Green Infrastructure Foundation is a charitable organization with a mission is to promote green infrastructure across North America through education. To view the photos associated with this press release, please visit the following links:

Drake J.,University of Toronto | Young D.,Toronto and Region Conservation Authority | McIntosh N.,University of Toronto
Water (Switzerland) | Year: 2016

The transportation of pollutants from impervious surfaces during runoff events to receiving water bodies is a serious environmental problem. Summer runoff is also heated by impervious surfaces, causing thermal enrichment in receiving water body systems and degradation of coldwater aquatic ecosystems. End-of-pipe stormwater management facilities that are open to the environment can result in further elevated temperatures due to exposure to solar radiation. Receiving water systems that provide coldwater habitat require cool water temperatures to sustain healthy conditions for cold water flora and fauna (e.g., trout, dace). Underground Stormwater Detention Chambers (USDC) are a technology for the detention and treatment of stormwater runoff that can potentially solve the thermal issues associated with sun-exposed detention facilities while still providing an equivalent level of treatment services for stormwater pollutants. A field study of an USDC located in Southern Ontario was undertaken to characterize its treatment performance and effect on water temperature. The results were: the USDC was found to provide similar levels of stormwater treatment as wet detention ponds. On average, outlet maximum temperatures were 5 °C cooler than inlet maximum temperatures, and outlet water temperatures remained within the thermal regime for coldwater fish habitat throughout the evaluation period. There was little to no stratification of temperature, nor dissolved solids, but stratification of dissolved oxygen was observed mid-winter and into the spring. © 2016 by the authors.

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.

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.

Wallace A.M.,Toronto and Region Conservation Authority | Biastoch R.G.,Toronto and Region Conservation Authority
Freshwater Science | Year: 2016

Salinization of streams is a growing ecological concern in urban areas. Winter application of deicers to roads (road salt) in cold climates strongly influences stream water chemistry. Total salt use and associated stream Cl-concentrations have increased in North American cities over the past few decades such that current elevated Cl-levels represent an evolutionarily novel stressor to freshwater biological communities. We investigated changes in stream Cl-concentrations between 2002 and 2012 in Toronto, Canada, and related Cl-concentrations to corresponDing changes in benthic macroinvertebrates over the same period. Median stream Cl-concentrations in 2012 were almost 2× higher than the median concentrations in 2002, despite the mild winter in 2012. We used the strong relationship between field conductivity and laboratory Cl-concentrations (R2 = 0.93) to model summer Cl-values for 51 benthic macroinvertebrate (BMI) sampling sites in 2002 and 2012. We investigated BMI community shifts with respect to Cl-with conventional metrics and Threshold Indicator Taxa ANalysis (TITAN). Conventional metrics failed to show a coherent pattern of the change between 2002 and 2012, but TITAN results showed that the number of taxa sensitive to Cl-decreased and the number of taxa tolerant of Cl-increased between 2002 and 2012. We identified a BMI community threshold in 2002 with a range of ?50 to 90 mg/L of Cl-, the level at which the community demonstrated the most taxa changes. The 50 to 90 mg/L threshold is below the Canadian Water Quality Guideline of 120 mg/L for chronic exposure to Cl-. Thus, Cl-may be having nonlethal effects on the BMI community. © 2016 by The Society for Freshwater Science.

Wallace A.M.,Toronto and Region Conservation Authority | Croft-White M.V.,Toronto and Region Conservation Authority | Moryk J.,Toronto and Region Conservation Authority
Environmental Monitoring and Assessment | Year: 2013

Impacts of urbanization on aquatic ecosystems are intensifying as urban sprawl spreads across the global land base. The urban stream syndrome (USS) identifies "symptoms" associated with urban development including changes in biotic communities, hydrology, water chemistry, and channel morphology. Direct relationships between road density (as surrogate of urbanization) and indicators of the USS were identified for streams in the Toronto region. Significant negative relationships were revealed between road density and biological (fish and benthic macroinvertebrate) richness, diversity, and fish Index of Biotic Integrity scores. Significant positive relationships were found between road density and tolerant fish/benthic macroinvertbrates, benthos Family Biotic Index scores, mean summer stream temperature, stream flashiness, and several water quality variables. Analysis of biological data showed that only four fish species and a reduced number of benthic macroinvertebrate families remained at the most urbanized sites. Road density was found to be a major determinant in both the fish and benthic macroinvertebrate community structure. © 2013 Springer Science+Business Media Dordrecht.

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.

Trenouth W.R.,University of Guelph | Gharabaghi B.,University of Guelph | MacMillan G.,Toronto and Region Conservation Authority | Bradford A.,University of Guelph
Inland Waters | Year: 2013

Several areas within the Lake Simcoe watershed, Canada, are experiencing rapid urban development. The construction of new homes and businesses is frequently associated with elevated rates of soil erosion stemming from land clearing and grading activities. During development, rates of soil erosion can climb to levels that are typically 200 times above background conditions, with the eroded sediments entering waterways and causing harm to the biota living therein. This is a serious challenge for the communities around Lake Simcoe because the transport of sediment has previously been identified as a contributor to the eutrophication of the lake's waters. To mitigate the negative impacts associated with development, many jurisdictions across North America and elsewhere have developed a suite of construction-phase stormwater management (CPSWM) guidelines, which entail the use of onsite best management practices that capture, detain, and treat sediment-laden surface runoff. Here, we review CPSWM guidelines for effluent discharge and receiving water quality and discuss the relative strengths and weaknesses of each approach. Finally, proposed revisions to the current Ontario guidelines are suggested based on a combination of field observations at predevelopment and active construction sites, as well as the reviewed literature. If adopted, the proposed revisions would help to reduce sediment transport from construction sites in rapidly urbanizing areas such as Lake Simcoe. © International Society of Limnology 2013.

Kricsfalusy V.V.,Toronto and Region Conservation Authority | Kricsfalusy V.V.,University of Saskatchewan | Miller G.C.,Toronto and Region Conservation Authority
Thaiszia Journal of Botany | Year: 2010

Habitat preferences of the invasive alien species Cynanchum rossicum (KLEOPOW) BORHIDI in northeastern United States and southeastern Canada are characterized on the basis of data from both field studies and literature. C. rossicum behaves more as a habitat generalist in North America, compared to its native range in Europe, particularly with respect to shade tolerance and soil type. It is prevalent in forest habitats as well as open meadow and savannah or woodland; and occurs mainly on loam and sandy loam soils. The ecology and structure of vegetation communities affected by C.rossicum is analyzed in the Toronto region, Canada where the phytocoenological optimum of C. rossicum occurs in semi-open communities. C. rossicum tends to be the primary or secondary dominant species in infested vegetation community polygons (43% and 26%, respectively). The area infested by C. rossicum includes 1813.21 ha or 7.25% of surveyed natural cover in the Toronto region. Young-to-mid-aged forests and plantations as well as semi-open successional communities tend to have the most severe infestations. C. rossicum is a serious threat to rare plant communities such as alvars, tallgrass oak savannahs and woodlands and their associated species.

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