CARRUTHERS CREEK WATERSHED PLAN

PREPARING FOR THE FUTURE

Toronto and Region Conservation Authority (TRCA), in partnership with the Region of Durham, is undertaking an update to the last Watershed Plan for Carruthers Creek, which was completed in 2003.

As we strive to develop a comprehensive watershed plan for the Carruthers Creek watershed, TRCA acknowledges that this watershed planning was undertaken within the traditional territory and treaty lands of the Anishinaabeg of the Williams Treaty First Nations, and the traditional territory of the Huron-Wendat Nation. As stewards of land and water resources within the Greater Toronto Region, TRCA appreciates and recognizes the history and diversity of the land, as well as our shared values and interests and is respectful of working in this territory.

Why do we need an update?

TRCA will assess changes and impacts which have occurred since 2003 and review the current conditions of the watershed. We will recommend actions to keep the watershed healthy over the long-term.

The new Plan will guide future decision-making for the watershed by the Region of Durham, the City of Pickering, the Town of Ajax, TRCA, and watershed residents, neighbours, businesses, and other stakeholders. Watershed Plans do not make decisions about land use.

How do you create a Watershed Plan?

TRCA will revisit the Vision and Management Philosophy established for Carruthers Creek watershed in 2003 as a foundation for the new Plan.

Scientists working on the Watershed Plan assess the watershed's current conditions by studying various features and functions including groundwater, geology, plants and animals, water quality, and the movement and changes in the stream over time.

Our scientific work will be reviewed by independent experts in each field, to ensure we relied on the best available science and our work is impartial and rigorous.

The resulting Watershed Plan will make recommendations for the protection, restoration, enhancement, and overall management of the watershed over the long-term.

Learn more about peer review of the Watershed Plan

How can I get involved?


Where is Carruthers Creek watershed?

(Click map to enlarge)

PREPARING FOR THE FUTURE

Toronto and Region Conservation Authority (TRCA), in partnership with the Region of Durham, is undertaking an update to the last Watershed Plan for Carruthers Creek, which was completed in 2003.

As we strive to develop a comprehensive watershed plan for the Carruthers Creek watershed, TRCA acknowledges that this watershed planning was undertaken within the traditional territory and treaty lands of the Anishinaabeg of the Williams Treaty First Nations, and the traditional territory of the Huron-Wendat Nation. As stewards of land and water resources within the Greater Toronto Region, TRCA appreciates and recognizes the history and diversity of the land, as well as our shared values and interests and is respectful of working in this territory.

Why do we need an update?

TRCA will assess changes and impacts which have occurred since 2003 and review the current conditions of the watershed. We will recommend actions to keep the watershed healthy over the long-term.

The new Plan will guide future decision-making for the watershed by the Region of Durham, the City of Pickering, the Town of Ajax, TRCA, and watershed residents, neighbours, businesses, and other stakeholders. Watershed Plans do not make decisions about land use.

How do you create a Watershed Plan?

TRCA will revisit the Vision and Management Philosophy established for Carruthers Creek watershed in 2003 as a foundation for the new Plan.

Scientists working on the Watershed Plan assess the watershed's current conditions by studying various features and functions including groundwater, geology, plants and animals, water quality, and the movement and changes in the stream over time.

Our scientific work will be reviewed by independent experts in each field, to ensure we relied on the best available science and our work is impartial and rigorous.

The resulting Watershed Plan will make recommendations for the protection, restoration, enhancement, and overall management of the watershed over the long-term.

Learn more about peer review of the Watershed Plan

How can I get involved?


Where is Carruthers Creek watershed?

(Click map to enlarge)

  • Feedback on the Draft Management Framework

    7 days ago

    The Carruthers Creek Watershed Plan will aim to protect the ecological health of Carruthers Creek for present and future generations. Community input on the plan’s Management Framework will help TRCA and the Region of Durham create a healthier future for Carruthers Creek. By attending one of the two upcoming Public Open House events, on October 8 in Ajax or October 10 in Pickering, community members can speak with technical experts and give feedback on the plan’s draft Management Framework, which will address proposed urban canopy enhancements, aquatic species protection, flooding and erosion management, water quality management and more.

    If...

    The Carruthers Creek Watershed Plan will aim to protect the ecological health of Carruthers Creek for present and future generations. Community input on the plan’s Management Framework will help TRCA and the Region of Durham create a healthier future for Carruthers Creek. By attending one of the two upcoming Public Open House events, on October 8 in Ajax or October 10 in Pickering, community members can speak with technical experts and give feedback on the plan’s draft Management Framework, which will address proposed urban canopy enhancements, aquatic species protection, flooding and erosion management, water quality management and more.

    If you are unable to make one of the Public Open House events, don't worry! All of the Open House Information Panels have been uploaded in Reports and Resources. Once you have had a chance to review the information don't forget to submit your feedback. You can submit your feedback by completing the Comment Form by Friday, October 18th, 2019.

    As always, you can Ask a Question through the Project Website or send an e-mail to carruthers@trca.ca.

  • Carruthers Creek Watershed Plan - Upcoming Public Open Houses

    about 2 months ago
    Carruthers ehq postcard final page 001

    As part of the consultation process for the Carruthers Creek Watershed Plan (CCWP) the Toronto and Region Conservation Authority (TRCA), in partnership with the Region of Durham, is hosting two (2) Public Open Houses to solicit feedback on the plan’s draft Management Framework. These Open Houses will be drop-in style where you can learn about the Carruthers Creek watershed, speak with technical experts, and learn about the management recommendations drafted as part of the watershed plan.


    Public Open House #1:

    Date: Tuesday, October 8th, 2019

    Time: 6:00pm - 9:00pm

    Location: Carruthers Marsh Pavilion (55 Ashbury Boulevard West, Ajax, ON,...

    As part of the consultation process for the Carruthers Creek Watershed Plan (CCWP) the Toronto and Region Conservation Authority (TRCA), in partnership with the Region of Durham, is hosting two (2) Public Open Houses to solicit feedback on the plan’s draft Management Framework. These Open Houses will be drop-in style where you can learn about the Carruthers Creek watershed, speak with technical experts, and learn about the management recommendations drafted as part of the watershed plan.


    Public Open House #1:

    Date: Tuesday, October 8th, 2019

    Time: 6:00pm - 9:00pm

    Location: Carruthers Marsh Pavilion (55 Ashbury Boulevard West, Ajax, ON, L1Z 0E1)


    Public Open House #2:

    Date: Thursday, October 10th, 2019

    Time: 6:00pm - 9:00pm

    Location: Mt. Zion Community Hall (4230 Salem Road, Pickering, ON, L0C 1A0)


    While it may be a small watershed in Durham Region, Carruthers Creek is certainly an important one. Connecting Pickering and Ajax, this unique watershed, home to several rare plants and fish, drains into the north shore of Lake Ontario. A new Watershed Plan will aim to protect the ecological health of Carruthers Creek now and in the future. Community input on the Management Framework will help TRCA and the Region of Durham create a healthier future for Carruthers Creek.


    The final plan will not result in a decision on future land use designations. Rather, it will recommend management actions focused on the protection, restoration, enhancement, and long-term management of the watershed. The recommendations will apply to existing land uses, and potential changes throughout the entire watershed.


  • Carruthers Creek Watershed Plan Update - Summer 2019

    2 months ago

    As part of the commitments in the CCWP Communications and Consultation Strategy, Toronto and Region Conservation Authority (TRCA) staff are required to provide an update to municipal councils and/or committees at key milestones identified throughout the project.

    In Spring 2019, TRCA staff provided an update to:

    The update, and associated Staff Reports, provided an overview to municipal council members on the status of the CCWP....

    As part of the commitments in the CCWP Communications and Consultation Strategy, Toronto and Region Conservation Authority (TRCA) staff are required to provide an update to municipal councils and/or committees at key milestones identified throughout the project.

    In Spring 2019, TRCA staff provided an update to:

    The update, and associated Staff Reports, provided an overview to municipal council members on the status of the CCWP. Specifically, the update focused on Phase 2 communication and consultation, the updated Vision Statement for the CCWP, the development process of the Management Framework, and next steps.

    A PDF copy of the CCWP Update Presentation - Spring 2019 has been uploaded to the Document Library.

    Stay tuned to learn more about the Public Information Centres (PICs) being hosted in October 2019. These PICs will consult the public and all stakeholders to gather feedback on the Draft Management Framework for the CCWP.

  • A New Vision

    4 months ago

    As discussed in an earlier blog post, one of the main objectives of consultation during Phase 2, Stage 1 was to create a new vision statement for the Carruthers Creek Watershed Plan by gathering feedback on the vision statement from the 2003 Watershed Plan for Carruthers Creek.

    Generally, the feedback received on the 2003 Watershed Vision is that it is a good statement and remains relevant. When asked about what the public would like the New Vision to say, some responses were:


    “The essence of the (2003) Vision is on the mark. Enhance and protect the Carruthers Creek...

    As discussed in an earlier blog post, one of the main objectives of consultation during Phase 2, Stage 1 was to create a new vision statement for the Carruthers Creek Watershed Plan by gathering feedback on the vision statement from the 2003 Watershed Plan for Carruthers Creek.

    Generally, the feedback received on the 2003 Watershed Vision is that it is a good statement and remains relevant. When asked about what the public would like the New Vision to say, some responses were:


    “The essence of the (2003) Vision is on the mark. Enhance and protect the Carruthers Creek Watershed to ensure that it continues to provide valuable environmental and societal benefits to the community.”

    - Watershed Resident


    “The Vision needs to emphasize sustainability, climate change and biodiversity and retrofitting existing areas. The importance of continued research and science are important to acknowledge.”

    - Environmental Stakeholder


    There is a desire to update the Vision with current language and to incorporate new concepts and approaches. It was also noted that a succinct statement would make it easier to be understood and recalled by residents and stakeholders. The following ideas were frequently suggested for inclusion in the New Vision:

    • Incorporate resiliency and adaptation to climate change.
    • Have more focus on biodiversity and improving ecological health and integrity through a systems management approach.
    • Incorporate more emphasis on sustainability, restoration and retrofitting existing urban areas.
    • Highlight the importance of continued research and science.
    • More focus on health benefits of nature not just the risk versus benefit.
    • Encourage all stakeholders to participate in the stewardship of the watershed.
    After incorporating all feedback from various stakeholders, the New Vision now reads:

    Carruthers Creek watershed is a healthy and resilient natural system that is managed through partnerships to balance resource protection with human activity. Sound science and best management practices will protect and restore ecosystem functions, protect watershed residents from natural hazards like flooding, and maintain our natural heritage and water resources for present and future generations.


    TRCA and Region of Durham would like to sincerely thank all of the community members, stakeholders, and municipal staff who have dedicated their time to provide feedback to develop this New Vision for the Carruthers Creek Watershed Plan.


  • Carruthers Creek Watershed Plan: Communications and Consultation Summary (Phase 2, Stage1)

    5 months ago
    Picture1
    As part of Phase 2 of the Carruthers Creek Watershed Plan (CCWP), TRCA is undertaking extensive stakeholder and public consultation. Consultation will occur in three (3) stages throughout Phase 2 of the CCWP and will follow the Carruthers Creek Watershed Plan Communications and Consultation Strategy. The Communications and Consultation Strategy was received by Durham Regional Council in May 2018, and time lines were refined at Council’s request in June 2018.

    Phase 2, Stage 1 began in December 2017 and was completed in October 2018. The Carruthers Creek Watershed Plan: Communications and Consultation Summary (Phase 2, Stage1) was created to...

    As part of Phase 2 of the Carruthers Creek Watershed Plan (CCWP), TRCA is undertaking extensive stakeholder and public consultation. Consultation will occur in three (3) stages throughout Phase 2 of the CCWP and will follow the Carruthers Creek Watershed Plan Communications and Consultation Strategy. The Communications and Consultation Strategy was received by Durham Regional Council in May 2018, and time lines were refined at Council’s request in June 2018.

    Phase 2, Stage 1 began in December 2017 and was completed in October 2018. The Carruthers Creek Watershed Plan: Communications and Consultation Summary (Phase 2, Stage1) was created to outline the objectives which guided the communications and consultation and describes the methods and activities used to inform and consult the public and stakeholders. It also describes what was heard and how public input is reflected in the new Vision Statement and ongoing Phase 2 work. The summary report is now available in our Reports and Resources library.

    Figure 1: Over 600 residents were engaged at seven pop-Up events across Pickering and Ajax. The pop-up events were interactive and designed to gather feedback about the CCWP process and Vision statement.


    The consultation for Phase 2, Stage 1 had three (3) main objectives:

    1. Raise awareness about the Carruthers Creek Watershed Plan.
    2. Inform partners, stakeholders, and the general public about the process for updating the Watershed Plan.
    3. Gather feedback on the Vision developed for the 2003 Watershed Plan and preliminary issues and ideas to be considered in all the Phase 2 work.

    Figure 2: Thousands of public comments were received at pop-up events, presentations, stakeholder workshops, through the CCWP Website, and as part of an online survey.


    During this initial stage, consultation was undertaken to seek input on a new Vision Statement for the Watershed Plan. The new Vision Statement will be highlighted in a future blog post. Consultation will also be undertaken in subsequent stages to solicit feedback on the draft Management Recommendations (Stage 2) and draft Watershed Plan (Stage 3).






  • Recreational Trails in Carruthers Creek Watershed

    7 months ago
    Playdiscover parkstrailsconser sm

    Now that spring weather has finally arrived, it is time to get your bicycle and running shoes out of storage and get outdoors! The Town of Ajax and City of Pickering have an abundance of parks, playgrounds, trails and conservation areas for you to enjoy. You can explore safe, connected, trails that are perfect for hiking, cycling, walking or simply just to take advantage of the beauty of nature.

    Figure 1: The Town of Ajax and City of Pickering have a beautiful Waterfront Trail along Lake Ontario (Photo courtesy Town of Ajax)


    In 2016, a 5km section of the Carruthers...

    Now that spring weather has finally arrived, it is time to get your bicycle and running shoes out of storage and get outdoors! The Town of Ajax and City of Pickering have an abundance of parks, playgrounds, trails and conservation areas for you to enjoy. You can explore safe, connected, trails that are perfect for hiking, cycling, walking or simply just to take advantage of the beauty of nature.

    Figure 1: The Town of Ajax and City of Pickering have a beautiful Waterfront Trail along Lake Ontario (Photo courtesy Town of Ajax)


    In 2016, a 5km section of the Carruthers Creek Trail was completed between Taunton Road and Kingston Road in Ajax. This trail is off-road and safe for all levels of trail users.


    Figure 2: A photo from the newest section of the Carruthers Creek Trail in Ajax (Photo courtest Town of Ajax).




    Figure 3: A photo from the newest section of the Carruthers Creek Trail in Ajax (Photo courtesy Town of Ajax).


    To plan your next outing, you can view a map of the Carruthers Creek Trail, and other trails, on the Town of Ajax Trail Map.


  • Carruthers Creek Watershed Plan: Fluvial Geomorphology Assessment

    7 months ago
    Img 20150605 100636

    This week's post will highlight the results of the Fluvial Geomorphology Assessment completed for the Carruthers Creek Watershed Plan.

    What is Fluvial Geomorphology?

    Fluvial geomorphology is the study of the form and function of streams and the interaction between streams and the landscape around them. ‘Fluvial’ refers to the processes associated with running waters, ‘geo’ refers to earth and ‘morphology’ refers to channel shape. Stream morphology is dynamic and constantly changing in both space and time. A stable stream channel is in a state of equilibrium and responds physically to the streamflow and sediment it receives from upstream.

    Fluvial Geomorphology...

    This week's post will highlight the results of the Fluvial Geomorphology Assessment completed for the Carruthers Creek Watershed Plan.

    What is Fluvial Geomorphology?

    Fluvial geomorphology is the study of the form and function of streams and the interaction between streams and the landscape around them. ‘Fluvial’ refers to the processes associated with running waters, ‘geo’ refers to earth and ‘morphology’ refers to channel shape. Stream morphology is dynamic and constantly changing in both space and time. A stable stream channel is in a state of equilibrium and responds physically to the streamflow and sediment it receives from upstream.

    Fluvial Geomorphology of Carruthers Creek

    This report characterized the channel morphology (the rate and locations of the movement of stream channels) in Carruthers Creek since the 2003 watershed plan was completed. Characterizing the channel morphology of a watershed is important because the physical form and function of a watercourse are key elements of aquatic habitat. Furthermore, establishing baseline conditions enables watershed managers to assess potential impacts from changes to the watershed.

    Methodology

    Following the completion of the 2003 watershed plan for Carruthers Creek, TRCA established the Regional Watershed Monitoring Program (RWMP). Under this program, Matrix Solutions Inc. established ten (10) monitoring stations along Carruthers Creek which were updated every three (3) years from 2003-2012. For this assessment, Matrix Solutions Inc. completed an updated desktop assessment (using aerial imagery) and data collected from the RWMP during detailed site visits in 2016 at all ten (10) monitoring stations. The report contains an anlysis of the full monitoring datasets from 2003, 2006, 2009, 2012, and 2016.

    Results

    Overall, the 13-year monitoring period provided a unique opportunity to document changes in channel morphology for the purposes of understanding channel processes. The assessment indicates that Carruthers Creek is an active channel, whether the cross-section is enlarging, aggrading, or continually adjusting while maintaining a similar size. Sites on the smaller tributaries of the creek suggest that channel dimensions are increasing. Comparatively, while the main branch sites exhibit active channel processes, overall change was minimal. This indicates the larger channel's resilience to changes in the surrounding area.


    Conclusion

    The information collected as part of this assessment will be used during Phase 2 of the watershed planning process to make recommendations for management of the natural heritage system and watercourses. To read the full Fluvial Geomorphology Assessment, please click here.

  • Carruthers Creek Watershed Plan: Terrestrial Biological Inventory and Assessment

    8 months ago
    Swamp rose

    This week's post will highlight the results of the Terrestrial Biological Inventory and Assessment completed for the Carruthers Creek Watershed Plan.

    In 2015, TRCA staff conducted an in-depth ecological inventory of the Carruthers Creek watershed that covered 970 hectares (92%) of the watershed's entire natural cover. Inventories were conducted at the levels of habitat patch (landscape analysis), vegetation community, and species (both flora and fauna).

    Land Classification

    The inventories found 173 different ELC vegetation community types including 47 different natural forest communities, 22 plantations, 23 successional communities, 15 wetlands, 13 aquatic communities, 14 dynamic communities (e.g. savannah, beaches, bluffs), and...

    This week's post will highlight the results of the Terrestrial Biological Inventory and Assessment completed for the Carruthers Creek Watershed Plan.

    In 2015, TRCA staff conducted an in-depth ecological inventory of the Carruthers Creek watershed that covered 970 hectares (92%) of the watershed's entire natural cover. Inventories were conducted at the levels of habitat patch (landscape analysis), vegetation community, and species (both flora and fauna).

    Land Classification

    The inventories found 173 different ELC vegetation community types including 47 different natural forest communities, 22 plantations, 23 successional communities, 15 wetlands, 13 aquatic communities, 14 dynamic communities (e.g. savannah, beaches, bluffs), and 3 meadow types.

    Flora

    A total of 935 species of vascular plants were recorded including 845 naturally-occurring species. Of the naturally-occurring plants, 484 (57%) are native and 361 (43%) are non-native. Four (4) of the 153 flora species of regional conservation concern have not been found anywhere else in TRCA's jurisdiction. All four species are associated with wetlands and include sessile-fruited arrowhead, few-flowered spike rush, swamp rose, and shore horsetail. Carruthers Creek watershed has significant infestations of invasive exotic plants such as dog-strangling vine, garlic mustard, and common buckthorn.

    Figure 1: Swamp Rose (Rosa palustris) was found in the Carruthers Creek watershed in 2015

    Figure 2: Sessile-fruited arrow-head (Sagittaria rigida) was found in Carruthers Marsh at the mouth of Carruthers Creek.


    Fauna

    Inventories documented a total of 133 possible breeding vertebrate fauna species over the past decade. This total is composed of 106 breeding birds, 18 mammals, and 9 herpetofauna. Of note is a small colony of great blue herons located in "Ajax Warbler Swamp" (east side of Shoal Point Road, south of Bayly), grasshopper sparrow (listed as Special Concern under COSSARO), ermine, and grey treefrog. For a complete list of recorded fauna, please read the full technical report.

    Figure 3: A small colony of great blue herons (Ardea herodias) was recorded in the Carruthers Creek watershed.

    Figure 4: Rare within the region, a single grasshopper sparrow (Ammodramus savannarum) territory was located in the agricultural upper reaches of the watershed.


    Conclusion

    This report characterizes the vegetation and wildlife found within the Carruthers Creek watershed in the context of the quantity and quality of the available habitat patches. The amount of natural cover, along with the quality and distribution throughout the watershed, is not only important habitat for wildlife, but it also performs many ecosystem services for people. Natural cover improves air quality, reduces the risk of flooding and provides opportunities for pollination of food crops. The data collected will be used in later phases of the watershed plan to determine recommendations for management and protection of terrestrial wildlife.

    To read the full Terrestrial Biological Inventory and Assessment , and to see complete records of observed fauna and flora species, please click here.

  • Carruthers Creek Watershed Plan: Hydrogeology Report

    8 months ago
    Physiogeographic regions

    This week's post will highlight the results from the technical report on the Hydrogeology of Carruthers Creek completed by the Oak Ridges Moraine Groundwater Program.

    The purpose of this technical report was to document the current understanding of the groundwater conditions within the Carruthers Creek watershed. Carruthers Creek drains an area of 3,840 hectares and occurs within two (2) physiogeographic regions which include:

    • The South Slope - occurring to the south of the Oak Ridges Moraine (ORM) and largely consisting of till deposits at surface with a localized lacustrine veneer.
    • The Glacial Lake Iroquois Plain -...

    This week's post will highlight the results from the technical report on the Hydrogeology of Carruthers Creek completed by the Oak Ridges Moraine Groundwater Program.

    The purpose of this technical report was to document the current understanding of the groundwater conditions within the Carruthers Creek watershed. Carruthers Creek drains an area of 3,840 hectares and occurs within two (2) physiogeographic regions which include:

    • The South Slope - occurring to the south of the Oak Ridges Moraine (ORM) and largely consisting of till deposits at surface with a localized lacustrine veneer.
    • The Glacial Lake Iroquois Plain - occurring immediately north of Lake Ontario and consisting of sand, silt, and clay deposits.


    Figure 1: Physiogeographic regions within the Carruthers Creek Watershed Plan study area.


    The groundwater conditions within Carruthers Creek watershed were documented utilizing high-quality data that exists within adjacent, directly-applicable watersheds. These data were augmented with relatively lower quality data (e.g. MOECC water well records) and streamflow gauging records that exist within the watershed.

    Three (3) aquifer systems are present within the watershed:

    • The Oak Ridges Moraine/Mackinaw Interstadial aquifer complex - a shallow aquifer complex that occurs beneath the surficial till deposits within the northern part of the watershed and locally to the Lake Iroquois shoreline at Whitevale Road.
    • The Thorncliffe aquifer complex - a deep aquifer complex located throughout the watershed and occur at a shallower depth south of the Lake Iroquois shoreline.
    • The Scarborough aquifer complex - a deep aquifer complex located throughout the watershed and occur at a shallower depth south of the Lake Iroquois shoreline.
    No municipal supplies from groundwater exist within the watershed. The southern part of the watershed (Lake Ontario to Taunton Road) is serviced by municipal water supplies from Lake Ontario. Water supply in rural areas (north of Taunton Road) is obtained from groundwater from wells for private homes and farms.

    Some data gaps exist relative to hydrogeology in the watershed and will be addressed in Phase 2 of the Watershed Plan process through the installation of groundwater monitoring wells in Pickering. These monitoring wells allow for measurement of groundwater level changes and groundwater quality.

    To read the detailed results of the Hydrogeology Report please click here.

  • Carruthers Creek Watershed Plan: Surface Water Quality Characterization

    8 months ago
    Water quality sampling resize

    Thank you for continuing to follow along as we summarize the Carruthers Creek Watershed Plan technical reports. This week's post will highlight the results from the technical report on the Characterization of Surface Water Quality

    Surface water quality is variable in all watersheds and reflects the local sources, contributions, and land use in the watershed. It can negatively impact the health of a watershed by causing eutrophication, toxicity to aquatic life, poor water clarity, and poor aesthetics.

    The purpose of the Surface Water Quality Characterization report was to determine benchmark water quality conditions, determine the variability between sites within the...

    Thank you for continuing to follow along as we summarize the Carruthers Creek Watershed Plan technical reports. This week's post will highlight the results from the technical report on the Characterization of Surface Water Quality

    Surface water quality is variable in all watersheds and reflects the local sources, contributions, and land use in the watershed. It can negatively impact the health of a watershed by causing eutrophication, toxicity to aquatic life, poor water clarity, and poor aesthetics.

    The purpose of the Surface Water Quality Characterization report was to determine benchmark water quality conditions, determine the variability between sites within the watershed, and identify some of the factors influencing water quality in Carruthers Creek. To do this, a number of key water quality parameters were the focus of this report including phosphorus, nitrogen compounds, suspended solids, chlorides, E. coli, dissolved oxygen, and metals. These parameters were measured during both low flow (dry conditions) and high flows (storm runoff/snow melt conditions).

    Figure 1: A TRCA staff member sampling water for quality assessment.

    Carruthers Creek watershed has diverse land use that ranges from rural and agricultural to intense urbanization. Therefore, as part of this report, a total of three (3) sampling sites were located across the Carruthers Creek watershed. These sampling locations represented: rural lands with predominantly natural and agricultural influences (headwaters at Highway 7); conditions upstream of urban influences (at Squires Rd.); and conditions downstream of urban influences (at the mouth of Carruthers Creek).


    Figure 2: Land use has an impact on surface water quality throughout the watershed. Golf courses, as seen here, can have specific influences on water quality parameters.

    Surface Water Quality in the Headwaters

    The headwaters (at Highway 7) contain elevated concentrations of total phosphorus, phosphate, total ammonia, E. coli, total suspended solids, turbidity, and some trace metals. These elevated concentrations were likely influenced by agricultural practices and the construction of a major highway. Additionally, elevated soluble and particulate components during runoff events indicates that over-land transport and erosion are important to the water quality in Carruthers Creek.

    Surface Water Quality Upstream of Urban Development

    Below the Lake Iroquois shoreline, upstream of urban development (at Squires Rd.), concentrations were reduced for the majority of parameters except chloride which increased. The increase in chloride concentrations may be due to the influences of the residential estate subdivision in the eastern branch of Carruthers Creek.

    Surface Water Quality Downstream of Urban Development

    Chloride levels regularly exceeded the threshold for the protection of aquatic life in the reaches of Carruthers Creek with urban influences. Additionally, increased concentrations of total ammonia, nitrite, phosphate, turbidity, and trace metals are often observed downstream of the urban area. As expected, the concentrations of many water quality parameters were elevated during high flow conditions that occur during storm runoff and wet weather.

    Conclusion

    Exceedances of water quality objectives were often highest in the rural headwaters, lowest above the urban sampling location, and second highest below the urban area. Understanding of watershed delivery of nutrients, pollutants, and materials that affect water quality in the near shore of Lake Ontario is fundamental to inform management of both the lake and the watersheds that drain in to it.

    To read the detailed Surface Water Quality Characterization report please click here.