Floodline TRCA Line
This line feature represents the TRCA regulatory flood line produced directly from TRCA's flood plain maps (except where specified, see Description for more detail).
*NOTE: to obtain the feature as a polygon please click Floodline_TRCA_Polygon here.
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.
The segments of this feature fall under catagories as defined by the 'Layer' field of the feature's attribute table and are as follows:
Floodline-Engineered - the flood line from the finalized TRCA flood plain map.
Floodline-Estimated - the flood line from TRCA's estimated flood plain project. This flood line was created from a rough hydraulic model where the purpose was to define the regulatory flood plain in areas of the jurisdiction where there was a watercourse that met the criteria for flood plain mapping, but had not been modeled through previous study. This flood extent is intended for use as a criterion in TRCA regulation mapping and should not be used in place of a hydraulic analysis completed to TRCA standard.
Floodline- Engineered Flood Study - flood line acquired from a study not completed by the TRCA. These lines were specifically used with direction from the Planning and Development division for use in the Generic Regulation criteria layer and were complied from the submitted development application.
Floodline-Spill Unmapped - a flood plain spill exists where flood waters are not physically contained within the valley or stream corridor and exit into surrounding lands. As a consequence, the limit and depth of flooding are difficult to determine. Flood spill areas occur naturally or can occur as a result of downstream barriers to the passage of flood flows such as undersized bridges or culverts. Please refer to TRCA’s Living City Policies for further information on flood plain spills. This line segment does not represent the flood plain and is used only to indicate where the spill occurs.
Floodline-Spill Screening Area - 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. Draft 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 Engineering Services for further information.
Floodline-Update Pending - the flood line from the finalized TRCA flood plain map but indicated as an area where there is currently an update in progress.
Floodline-Undefined - this segment indicates where the extent of the flood plain is beyond the boundary limits of the topographical data that was available at the time the flood plain map was created.
Datasets available for download
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Floodline_TRCA_LineFeature Layer
Layer 0 via ArcGIS REST API
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Floodline_TRCA_Line (Explore)HTML
Explore Floodline_TRCA_Line on ArcGIS Hub
Additional Info
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| Last Updated | September 23, 2026, 08:10 (UTC) |
| Created | May 19, 2026, 16:31 (UTC) |
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Domain / Topic
Domain or topic of the dataset being cataloged.
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Title
Title for the Dataset.
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Floodline TRCA Line |
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Description
A description of the dataset.
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This line feature represents the TRCA regulatory flood line produced directly from TRCA's flood plain maps (except where specified, see Description for more detail). *NOTE: to obtain the feature as a polygon please click Floodline_TRCA_Polygon here. 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. The segments of this feature fall under catagories as defined by the 'Layer' field of the feature's attribute table and are as follows:
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Tags / Keywords
Keywords/tags categorizing the dataset.
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Format (CSV, XLS, TXT, PDF, etc)
File format of the dataset.
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Dataset Size
Dataset size in megabytes.
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52904.0 |
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Metadata Identifier
Metadata identifier – can be used as the unique identifier for catalogue entry
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Published Date
Published date of the dataset.
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2025-07-15 |
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Time Period Data Span (start date)
Start date of the data in the dataset.
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Time Period Data Span (end date)
End date of time data in the dataset.
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GeoSpatial Area Data Span
A spatial region or named place the dataset covers.
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Access category
Type of access granted for the dataset (open, closed, service, etc).
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public |
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License
License used to access the dataset.
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License not specified |
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Limits on use
Limits on use of data.
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Location
Location of the dataset.
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https://trca-camaps.opendata.arcgis.com/datasets/camaps::floodline-trca-line |
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Data Service
Data service for accessing a dataset.
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Owner
Owner of the dataset.
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trca.m.todd |
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Contact Point
Who to contact regarding access?
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Conservation Ontario |
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Contact Point Email
The email to contact regarding access?
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[email protected] |
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Publisher
Publisher of the dataset.
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Conservation Ontario |
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Publisher Email
Email of the publisher.
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Author
Author of the dataset.
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trca.m.todd |
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Author Email
Email of the author.
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Accessed At
Date the data and metadata was accessed.
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2026-09-21 |
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Identifier
Unique identifier for the dataset.
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33630fb21fcc400eb78eda205a90949c |
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Language
Language(s) of the dataset
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English |
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Link to dataset description
A URL to an external document describing the dataset.
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https://trca-camaps.opendata.arcgis.com/datasets/camaps::floodline-trca-line |
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Persistent Identifier
Data is identified by a persistent identifier.
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Globally Unique Identifier
Data is identified by a persistent and globally unique identifier.
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Contains data about individuals
Does the data hold data about individuals?
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Contains data about identifiable individuals
Does the data hold identifiable data about individual?
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Contains Indigenous Data
Does the data hold data about Indigenous communities?
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Portal Type
Platform type of the source portal.
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Version
Version of the datatset
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None |
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Source
Source of the dataset.
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None |
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Version notes
Version notes about the dataset.
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Is version of another dataset
Link to dataset that it is a version of.
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Other versions
Link to datasets that are versions of it.
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Provenance Text
Provenance Text of the data.
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Conservation Ontario |
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Provenance URL
Provenance URL of the data.
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Temporal resolution
Describes how granular the date/time data in the dataset is.
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GeoSpatial resolution in meters
Describes how granular (in meters) geospatial data is in the dataset.
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GeoSpatial resolution (in regions)
Describes how granular (in regions) geospatial data is in the dataset.
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Indigenous Community Permission
Who holds the Indigenous Community Permission. Who to contact regarding access to a dataset that has data about Indigenous communities.
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Community Permission
Community permission (who gave permission).
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The Indigenous communities the dataset is about
Indigenous communities from which data is derived.
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Number of data rows
If tabular dataset, total number of rows.
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5482 |
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Number of data columns
If tabular dataset, total number of unique columns.
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4 |
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Number of data cells
If tabular dataset, total number of cells with data.
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21928 |
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Number of data relations
If RDF dataset, total number of triples.
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Number of entities
If RDF dataset, total number of entities.
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Number of data properties
If RDF dataset, total number of unique properties used by the triples.
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Data quality
Describes the quality of the data in the dataset.
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Metric for data quality
A metric used to measure the quality of the data, such as missing values or invalid formats.
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