Key Natural Resource Issues in Conservation Halton’s Watersheds
Conservation Halton has identified 13 key watershed-wide natural resource issues and risks and other localized concerns that are addressed in our Watershed-Based Resource Management Strategy (“Watershed Strategy”). These issues and risks were identified in the context of climate change and based on a review of environmental monitoring data, technical reports/studies, a public survey, and the expertise of Conservation Halton’s staff. Learn more in our Watershed Characterization report linked below.
Summary of Key Natural Resource Issues
Review the 13 key watershed-wide natural resource issues and risks specific to our watersheds. Other natural resource issues in our watersheds are more localized and include dynamic beaches, shoreline erosion, shoreline flooding, surface/overland erosion, unstable bedrock (e.g., karst), and unstable soils.
Description: Flooding occurs when water overtops the banks of creeks and flows onto adjacent lands. Flooding results from intense rainfall over short periods of time, long periods of rainfall, heavy snow melt, or channel constrictions such as ice jams, debris, or undersized infrastructure. Other factors can worsen flood risk including the loss or degradation of natural features such as wetlands, increased impermeability of soils due to urbanization, illegal dumping of fill in creek valleys, physical alterations to creek banks which may cause waters to spill beyond the natural floodplain, and climate change.
Conservation Halton maps flood hazards according to provincial standards.
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Description: Drought occurs when there is a water shortage. It results from a period of persistent drier-than-normal conditions with below normal precipitation and high temperatures. Other factors that can worsen drought include the loss and fragmentation of forests and wetlands, an increase in the use of surface and groundwater, and climate change.
Conservation Halton monitors drought through our Low Water Response Program.
HISTORIC DROUGHTS | VULNERABLE AREAS | KEY IMPACTS |
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Description: Valley erosion occurs when there is an excessive loss of soil due to natural creek processes. Valley erosion results from periodic increases in peak creek flow, changes in channel form, unstable and steep slopes, loss of riparian vegetation (a strip of vegetation along the edge of a creek or waterbody), sediment load levels, ice jams, or soil type. This can cause bank slumping, scouring, undercutting, and ultimately slope failure. Other factors can worsen valley erosion including vegetation removal, construction activities in proximity to the slope (e.g., illegal dumping or excavation of fill in creek valleys, soil compaction, inadequate drainage, and new structures), poorly maintained infrastructure such as culverts and bridges, and climate change.
Conservation Halton maps valley erosion hazards according to provincial standards.
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Description: Chloride is released through natural processes such as bedrock weathering and precipitation. There have been significant increases in chloride concentrations in surface water over the last 50 years throughout the watershed. At least one sample taken from most monitoring sites over a recent five-year period exceeds the provincial guideline (e.g., Fourteen Mile Creek at Lakeshore Rd, Oakville; Sixteen Mile Creek Main Branch at Speers Rd; and Sheldon Creek at Shell Park, Oakville). Other factors can increase chloride concentrations including use of road salt and water softening salt, degraded and/or loss of natural features that filter water, stormwater management ponds, and wastewater treatment plant effluent.
Conservation Halton monitors chloride concentrations in surface water and ground water as part of the Provincial Water Quality Monitoring Network, and through our surface and groundwater water quality monitoring programs.
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Description: Suspended solids are materials such as silt, clay, plankton, and microscopic organisms that remain suspended in the water column. They typically carry pollutants and nutrients. Concentrations are variable throughout the watersheds depending on weather conditions (e.g., high during storm events and low during dry periods) and are influenced by erosion and the decomposition rate of organic materials. Other factors can increase suspended solids concentrations including loss of riparian vegetation, runoff from urban and agricultural areas, illegal dumping of fill in creek valleys, wastewater treatment plant effluent, and climate change.
Conservation Halton monitors suspended solids concentrations in surface water as part of the Provincial Water Quality Monitoring Network and through our surface water quality monitoring program.
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Description: Sedimentation occurs when solid particles settle out of suspension to the creek or pond bottom. Factors that increase sedimentation include runoff from poorly managed fields and construction sites with inadequate erosion and sediment controls, illegal dumping of fill in creek valleys, dams, weirs, and climate change.
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Description: Phosphorus is a nutrient released into the environment naturally through bedrock weathering and erosion processes. It binds to suspended sediment and causes increased plant growth, including algae. Total phosphorus is a measure of all phosphorus, whether dissolved or particulate. Average annual concentrations have exceeded the provincial guideline at almost all the watershed monitoring sites at least once over a recent five-year period (e.g., Fourteen Mile Creek at Lakeshore Rd; Bronte Creek upstream of Mountsberg Reservoir and Grindstone Creek at Hamilton Harbour). Concentrations are influenced by erosion and soil type. Other factors that can increase concentrations include fertilizer application, runoff from poorly managed fields, increased impermeability of soils in urban areas that increase stormwater runoff, loss of riparian vegetation that filter and store nutrients, municipal wastewater, and climate change.
Conservation Halton monitors total phosphorus concentrations as part of the Provincial Water Quality Monitoring Network and through our surface water quality monitoring program.
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Description: Thermal pollution occurs when surface water temperatures increase. Widespread increases in surface water temperatures have been recorded in central and downstream reaches across the watershed over the last 20 years. Surface water temperature is influenced by yearly and seasonal weather (e.g., wet versus dry, air temperature, etc.), sun exposure, creek channel form, groundwater discharge, and erosion (e.g., wider, shallower creeks with more surface area). Other factors can increase surface water temperature including increased impermeable surfaces and reduced natural shade in urban areas, loss of forests and riparian vegetation, use of dams and on-line ponds which increase surface exposure to sunlight, surface water takings which temporarily reduce water depth, and climate change.
Conservation Halton monitors surface water temperatures through our surface water quality monitoring program.
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Description: Groundwater is the water that infiltrates the soil, is stored, and moves underground. Private and municipal groundwater wells serve approximately 12% of Conservation Halton’s watershed population. The number of municipal drinking water system users is increasing. Groundwater quantity is influenced by the size of aquifers which are bodies of rock and/or sediment that hold groundwater, the ability of the materials in the ground to transmit water, and the loss and gain of water (water balance). Other factors can decrease groundwater quantity, including increased groundwater demand and excessive pumping, increased impermeability of soils due to urbanization, and climate change.
Conservation Halton monitors groundwater quantity through the Provincial Groundwater Monitoring Program and at selected wetland locations.
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Description: Groundwater quality is the physical, chemical, biological, and radiological characteristics of water under the earth’s surface. Water quality is described by measuring key characteristics or indicators such as chloride, sodium, nitrate, sulphate, arsenic, iron, lead, and manganese. Groundwater quality varies across the watersheds but is generally of good quality. However, some areas show trends of increasing chloride and sodium concentrations in well supplies. Groundwater quality is influenced by the permeability and chemical properties of the rocks and sediments through which it moves, the depth from ground surface, and natural climatic variations (e.g., rainfall and evaporation rates). Other factors can worsen water quality including the use of road salt and water softening salt, application of fertilizers, runoff from poorly managed fields, septic system effluent, and climate change.
Conservation Halton monitors groundwater quality indicators as part of the Provincial Groundwater Monitoring Network and through our groundwater quality monitoring programs.
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Description: Natural features include forests, wetlands, valleys, and water courses. They provide benefits and services such as flood attenuation, erosion control, carbon storage, filtration of contaminants, wildlife habitat, recreation, and more. In Conservations Halton’s watersheds, over 70% of wetlands have been lost or fragmented; remaining wetlands are located primarily in the upper watershed reaches. Riparian habitat coverage is variable but poor overall, especially in highly urbanized areas. Forest cover is poor overall. Large tracts of forest are rare (mostly above the Niagara Escarpment) and urban forests are small. Degradation, fragmentation, and loss of natural features are influenced by yearly and seasonal weather patterns, natural hazards (e.g., erosion, flooding, and drought), and disease. Other factors can worsen degradation and loss including the removal of natural features and wildlife corridors, urban encroachment, invasive species (e.g., Emerald Ash Borer), linear infrastructure (e.g., roads, utilities, etc.), and climate change.
Conservation Halton monitors biodiversity and ecological health through our Long-Term Ecological Monitoring Program (LEMP). Trends are monitored through our Ecological Land Classification (ELC) and Natural Areas Inventories.
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Description: Invasive species (e.g., Emerald Ash Borer and Garlic Mustard) are organisms that are not native to an area, adapt easily, reproduce quickly, and have a broader tolerance for a range of environmental conditions than native species. Natural features across Conservation Halton’s watershed, such as forests and wetlands, are negatively affected by invasive species. They are spread naturally by vectors such as wind, animals, insects and birds, and extreme weather events (e.g., hurricanes and flooding). Other factors can increase the spread including human activity (e.g., deliberate or accidental introduction of invasive species such as zebra mussels, goldfish, and purple loosestrife), and climate change.
Conservation Halton monitors the existence, spread and impact of invasive species.
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Description: Biodiversity loss is the decrease or disappearance of species. The status, health, and range of many species is shifting in Conservation Halton’s watersheds (e.g., decline of some tree species due to pests/pathogens). Biodiversity loss is influenced by yearly and seasonal weather patterns, natural hazards (e.g., erosion, flooding, and drought), and disease. Other factors that worsen biodiversity loss include loss of natural features and habitat, habitat degradation and fragmentation, spread of invasive species, and climate change.
Conservation Halton monitors biodiversity through our Long-Term Ecological Monitoring Program (LEMP) and Natural Areas Inventories.
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City of Burlington. Story Map: Climate Change Impacts. Accessed 七月 13, 2023.
Conservation Halton. 2002. Bronte Creek Watershed Study.
Conservation Halton. 2006. Northshore Watershed Study.
Conservation Halton. 2017. Water Quality in the Conservation Halton Watershed: 1964-2014.
Conservation Halton. 2018. Watershed Report Card.
Conservation Halton. 2018. Story Map: Terrestrial Monitoring.
Conservation Halton. 2018. Story Map: Aquatic Monitoring.
Conservation Halton. 2021. Story Map: How Much Habitat is Enough?
Conservation Halton. 2021. Story Map: Water Quality.
Conservation Halton, 2022. Water Temperature Data Analysis.
Conservation Halton. 2022. Story Map: Monitoring Watershed Health.
Conservation Halton. 2023. Watershed Report Card.
Environment and Climate Change Canada. 2019. Canada’s Changing Climate Report.
Gore and Storrie Limited and Ecoplans Limited. 1996. Sixteen Mile Creek Watershed Plan.
Halton Region. 2020. Climate Change Discussion Paper, Regional Official Plan Review.
Halton Region Conservation Authority. 1983. Interim Watershed Plan.
Halton Region Conservation Authority. 1998. Grindstone Creek Watershed Study.