Description: The valley Top of Slope is the break in slope point between the valley side slope and the tableland. The update of this version is based on consultation with TRCA development, infrastructure and technical review staff, municipalities, the development industry, and the public.The update was using 2019 Lidar contours, DEM and 2022 ortho photo.
Description: The Meander Belt Allowance provides a limit to development within the areas where the river system is likely to shift.The Meander Belt criterion was updated through the refinement of the existing Meander Belt created in 2006. The refinements include additions and removals of Meander Belt areas based on comments from TRCA planning staff and thru review of existing watercourse alignments using the most current available Orthophotos. The update was using 2022 ortho photo.
Description: Lower Don Flood Plain Landform defined by landform toe of slope. This feature will be added as a separate criteria layer for regulation limit. For further information, please contact Steve Heuchert.
Last update date: Dec 2020
Description: Wetland Area of Interference consists of evaluated and unevaluated wetlands derived from a combination of information from TRCA ELC and MNRF wetlands . The Water Resource System wetlands is also integrated into the source. It is 30m buffer adjacent to all wetlands. Generally, this layer is to be used for internal use only. Only to be sent externally with consent from Policy Planning. The update of this version is based on consultation with TRCA development, infrastructure and technical review staff, municipalities, the development industry, and the public.
Description: Properties in this area may be within the flood plain, or within a flood plain spill, and the corresponding sections of the Living City Policies may apply. Model information, or minimum floodproofing elevation requirements, may be available, or further studies may be required to determine if this property is impacted by a spill. Please contact TRCA for further information.
Description: The regulatory flood plain is the approved standard used in a particular watershed to define the limit of the flood plain for regulatory purposes. This standard is defined by the Ontario Ministry of Natural Resources and Forestry. Within TRCA’s jurisdiction, the regulatory flood plain is based on the more severe of the Regional Storm (Hurricane Hazel, 1954), or the 100 year storm; whichever is greater. For most of our jurisdiction, it is Hurricane Hazel. A hydrology model simulates the effect of this amount of rainfall as if it were over each watershed, taking into account the topography, soil type, land-use, and other characteristics to determine how much water would end up in our rivers and streams. A hydraulic model then looks at where this water would go, and what areas would be inundated. The inundated area for the regulatory storm is called the regulatory flood plain.
Description: The regulatory flood plain is the approved standard used in a particular watershed to define the limit of the flood plain for regulatory purposes. This standard is defined by the Ontario Ministry of Natural Resources and Forestry. Within TRCA’s jurisdiction, the regulatory flood plain is based on the more severe of the Regional Storm (Hurricane Hazel, 1954), or the 100 year storm; whichever is greater. For most of our jurisdiction, it is Hurricane Hazel. A hydrology model simulates the effect of this amount of rainfall as if it were over each watershed, taking into account the topography, soil type, land-use, and other characteristics to determine how much water would end up in our rivers and streams. A hydraulic model then looks at where this water would go, and what areas would be inundated. The inundated area for the regulatory storm is called the regulatory flood plain.
Description: This layer is from MNRF wetlands. The update of this version is based on consultation with TRCA development, infrastructure and technical review staff, municipalities, the development industry, and the public.The Water Resource System wetlands is also integrated into it.
Description: This layer is from MNRF wetlands. The update of this version is based on consultation with TRCA development, infrastructure and technical review staff, municipalities, the development industry, and the public.The Water Resource System wetlands is also integrated into it.
Description: This is a TRCA ELC wetlands and MNRF unevaluated wetlands combined layer where the area is greater than 0.5 ha. The update of this version is based on consultation with TRCA development, infrastructure and technical review staff, municipalities, the development industry, and the public. The Water Resource System wetlands is also integrated into it.
Description: This feature was created by merging the three features that are part of the Shoreline Hazard Limit as part of the Reference Manual - Determiniation of Regulation Limits. The three features are (named by feature name as they appear in the GDB) 1. FloodInundation 2. ErosionHazard_100YearErosionAllowance 3. ErosionHazard_DynamicBeach. After merging these features the resulting feature was dissolved. Please note that the 15 m buffer for the Regulation Limit allowance was NOT applied.
Description: The Meander Belt Allowance provides a limit to development within the areas where the river system is likely to shift.The Meander Belt criterion was updated through the refinement of the existing Meander Belt created in 2006. The refinements include additions and removals of Meander Belt areas based on comments from TRCA planning staff and thru review of existing watercourse alignments using the most current available Orthophotos. The update was using 2022 ortho photo.
Description: Lower Don Flood Plain Landform defined by landform toe of slope. This feature will be added as a separate criteria layer for regulation limit. For further information, please contact Steve Heuchert.
Last update date: Dec 2020
Description: Wetland Area of Interference consists of evaluated and unevaluated wetlands derived from a combination of information from TRCA ELC and MNRF wetlands . The Water Resource System wetlands is also integrated into the source. It is 30m buffer adjacent to all wetlands. Generally, this layer is to be used for internal use only. Only to be sent externally with consent from Policy Planning. The update of this version is based on consultation with TRCA development, infrastructure and technical review staff, municipalities, the development industry, and the public.
Description: Properties in this area may be within the flood plain, or within a flood plain spill, and the corresponding sections of the Living City Policies may apply. Model information, or minimum floodproofing elevation requirements, may be available, or further studies may be required to determine if this property is impacted by a spill. Please contact TRCA for further information.
Description: The regulatory flood plain is the approved standard used in a particular watershed to define the limit of the flood plain for regulatory purposes. This standard is defined by the Ontario Ministry of Natural Resources and Forestry. Within TRCA’s jurisdiction, the regulatory flood plain is based on the more severe of the Regional Storm (Hurricane Hazel, 1954), or the 100 year storm; whichever is greater. For most of our jurisdiction, it is Hurricane Hazel. A hydrology model simulates the effect of this amount of rainfall as if it were over each watershed, taking into account the topography, soil type, land-use, and other characteristics to determine how much water would end up in our rivers and streams. A hydraulic model then looks at where this water would go, and what areas would be inundated. The inundated area for the regulatory storm is called the regulatory flood plain.
Description: The regulatory flood plain is the approved standard used in a particular watershed to define the limit of the flood plain for regulatory purposes. This standard is defined by the Ontario Ministry of Natural Resources and Forestry. Within TRCA’s jurisdiction, the regulatory flood plain is based on the more severe of the Regional Storm (Hurricane Hazel, 1954), or the 100 year storm; whichever is greater. For most of our jurisdiction, it is Hurricane Hazel. A hydrology model simulates the effect of this amount of rainfall as if it were over each watershed, taking into account the topography, soil type, land-use, and other characteristics to determine how much water would end up in our rivers and streams. A hydraulic model then looks at where this water would go, and what areas would be inundated. The inundated area for the regulatory storm is called the regulatory flood plain.
Description: This layer is from MNRF wetlands. The update of this version is based on consultation with TRCA development, infrastructure and technical review staff, municipalities, the development industry, and the public.The Water Resource System wetlands is also integrated into it.
Description: This layer is from MNRF wetlands. The update of this version is based on consultation with TRCA development, infrastructure and technical review staff, municipalities, the development industry, and the public.The Water Resource System wetlands is also integrated into it.
Description: This is a TRCA ELC wetlands and MNRF unevaluated wetlands combined layer where the area is greater than 0.5 ha. The update of this version is based on consultation with TRCA development, infrastructure and technical review staff, municipalities, the development industry, and the public. The Water Resource System wetlands is also integrated into it.
Description: This feature was created by merging the three features that are part of the Shoreline Hazard Limit as part of the Reference Manual - Determiniation of Regulation Limits. The three features are (named by feature name as they appear in the GDB) 1. FloodInundation 2. ErosionHazard_100YearErosionAllowance 3. ErosionHazard_DynamicBeach. After merging these features the resulting feature was dissolved. Please note that the 15 m buffer for the Regulation Limit allowance was NOT applied.
Description: The Regulation Limit is mapped as the greatest extent of:
• 15m of criteria layers: Crest of slope, Meander Belt, Flood hazard engineered, Flood hazard Estimated, Shoreline Hazard
• the Areas of Interference (30 metres) adjacent to all wetlands.
The greatest extent of all features identified above is the Regulation Limit provided on the TRCA Regulation Limit mapping. It should be noted that compliance with this regulation does not exempt applicants from having regard for local by-laws, municipal and regional official plans (which incorporate provisions of the Oak Ridges Moraine Conservation Plan, the Growth Plan for the Greater Golden Horseshoe and the Greenbelt Plan), or the Provincial Policy Statement. TRCA’s Regulation mapping is a tool that conceptually shows the area of land within TRCA’s jurisdiction that is likely to be subject to the Regulation. The Regulation limit boundary is based on the best technical information available to TRCA at the time of the preparation of the map. Technical analysis that supports the mapping includes flood plain studies, provincial wetland mapping, ecological land classification mapping, digital elevation models, aerial photography, watercourse meander belt analysis, watercourse location mapping and Lake Ontario shoreline hazard assessment studies. The jurisdiction-wide update was completed in 2006 as part of the Generic Regulation conformity exercise. The 2019 comprehensive update to the existing mapping has been undertaken to reflect new technical information on current aerial photography. The 2022 update to the existing mapping has been undertaken to reflect new technical information on current aerial photography. TRCA is following the guidance provided by Conservation Ontario for regulation mapping updates.
Description: The Regulation Limit is mapped as the greatest extent of:
• 15m of criteria layers: Crest of slope, Meander Belt, Flood hazard engineered, Flood hazard Estimated, Shoreline Hazard
• the Areas of Interference (30 metres) adjacent to all wetlands.
The greatest extent of all features identified above is the Regulation Limit provided on the TRCA Regulation Limit mapping. It should be noted that compliance with this regulation does not exempt applicants from having regard for local by-laws, municipal and regional official plans (which incorporate provisions of the Oak Ridges Moraine Conservation Plan, the Growth Plan for the Greater Golden Horseshoe and the Greenbelt Plan), or the Provincial Policy Statement. TRCA’s Regulation mapping is a tool that conceptually shows the area of land within TRCA’s jurisdiction that is likely to be subject to the Regulation. The Regulation limit boundary is based on the best technical information available to TRCA at the time of the preparation of the map. Technical analysis that supports the mapping includes flood plain studies, provincial wetland mapping, ecological land classification mapping, digital elevation models, aerial photography, watercourse meander belt analysis, watercourse location mapping and Lake Ontario shoreline hazard assessment studies. The jurisdiction-wide update was completed in 2006 as part of the Generic Regulation conformity exercise. The 2019 comprehensive update to the existing mapping has been undertaken to reflect new technical information on current aerial photography. The 2022 update to the existing mapping has been undertaken to reflect new technical information on current aerial photography. TRCA is following the guidance provided by Conservation Ontario for regulation mapping updates.