Iroquois Shoreline (trca)

TRCA hydrogeology staff created the layer in Viewlog 4.0 by creating nodes at irregular intervals (perhaps 100 m intervals where the contours were tight and up to 1000 m where the break in slope was obvious and the surficial geology showed a till/sand contact). The interpretation largely relied upon Dr. Rick Gerber's rule of thumb of 135 m asl for the elevation of Lake Iroquois (established in the Duffins Watershed) but geological judgment was used where the OGS Surficial Geology and break in slope appeared to deviate from the rule of thumb. In addition, specific boreholes, such as the one installed by TRCA hydrogeology staff at West Deane Park along Mimico Creek where sands associated with the Iroquois shoreline were discovered, were relied upon to justify following the contours up river valley where erosion makes interpretation from surficial geology difficult. The layer was then exported as a shapefile.

During the review of the Carruthers Watershed, it came to the attention of TRCA hydrogeology staff that the Iroquois Shoreline in the Geologic Folder of the TRCA corporate data layers did not follow the Physiography established by Chapman and Putnam 1984 (The Physiography of Southern Ontario). It was then noted that within the Duffins Watershed the shoreline did not extend north along the Duffins River nor turn south along the height of land at the hamlet of Greenwood - instead the shoreline appeared to offset by about 1 km. TRCA hydrogeology staff brought the issue forward with Dr. Rick Gerber of the YPDT-CAMC team who stated that he had noticed the same thing when he prepared the Duffins and Carruthers watershed report in the early 2000s. He believed the error to be a NAD 83 / 27 conversion error.

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Additional Info

Field Value
Last Updated May 19, 2026, 16:32 (UTC)
Created May 19, 2026, 16:32 (UTC)
Domain / Topic
Domain or topic of the dataset being cataloged.
Title
Title for the Dataset.
Iroquois Shoreline (trca)
Description
A description of the dataset.

TRCA hydrogeology staff created the layer in Viewlog 4.0 by creating nodes at irregular intervals (perhaps 100 m intervals where the contours were tight and up to 1000 m where the break in slope was obvious and the surficial geology showed a till/sand contact). The interpretation largely relied upon Dr. Rick Gerber's rule of thumb of 135 m asl for the elevation of Lake Iroquois (established in the Duffins Watershed) but geological judgment was used where the OGS Surficial Geology and break in slope appeared to deviate from the rule of thumb. In addition, specific boreholes, such as the one installed by TRCA hydrogeology staff at West Deane Park along Mimico Creek where sands associated with the Iroquois shoreline were discovered, were relied upon to justify following the contours up river valley where erosion makes interpretation from surficial geology difficult. The layer was then exported as a shapefile.

During the review of the Carruthers Watershed, it came to the attention of TRCA hydrogeology staff that the Iroquois Shoreline in the Geologic Folder of the TRCA corporate data layers did not follow the Physiography established by Chapman and Putnam 1984 (The Physiography of Southern Ontario). It was then noted that within the Duffins Watershed the shoreline did not extend north along the Duffins River nor turn south along the height of land at the hamlet of Greenwood - instead the shoreline appeared to offset by about 1 km. TRCA hydrogeology staff brought the issue forward with Dr. Rick Gerber of the YPDT-CAMC team who stated that he had noticed the same thing when he prepared the Duffins and Carruthers watershed report in the early 2000s. He believed the error to be a NAD 83 / 27 conversion error.
Tags / Keywords
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Format (CSV, XLS, TXT, PDF, etc)
File format of the dataset.
Dataset Size
Dataset size in megabytes.
1144.0
Metadata Identifier
Metadata identifier – can be used as the unique identifier for catalogue entry
Published Date
Published date of the dataset.
2022-07-22
Time Period Data Span (start date)
Start date of the data in the dataset.
Time Period Data Span (end date)
End date of time data in the dataset.
GeoSpatial Area Data Span
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Field Value
Access category
Type of access granted for the dataset (open, closed, service, etc).
public
License
License used to access the dataset.
License not specified
Limits on use
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Location
Location of the dataset.
https://trca-camaps.opendata.arcgis.com/datasets/camaps::iroquois-shoreline-trca
Data Service
Data service for accessing a dataset.
Owner
Owner of the dataset.
jason.tam
Contact Point
Who to contact regarding access?
Conservation Ontario
Contact Point Email
The email to contact regarding access?
[email protected]
Publisher
Publisher of the dataset.
Conservation Ontario
Publisher Email
Email of the publisher.
Author
Author of the dataset.
jason.tam
Author Email
Email of the author.
Accessed At
Date the data and metadata was accessed.
2022-07-22
Field Value
Identifier
Unique identifier for the dataset.
68c862bb27a24c50995c5af77dc962b5
Language
Language(s) of the dataset
English
Link to dataset description
A URL to an external document describing the dataset.
https://trca-camaps.opendata.arcgis.com/datasets/camaps::iroquois-shoreline-trca
Persistent Identifier
Data is identified by a persistent identifier.
Globally Unique Identifier
Data is identified by a persistent and globally unique identifier.
Contains data about individuals
Does the data hold data about individuals?
Contains data about identifiable individuals
Does the data hold identifiable data about individual?
Contains Indigenous Data
Does the data hold data about Indigenous communities?
Portal Type
Platform type of the source portal.
Field Value
Version
Version of the datatset
None
Source
Source of the dataset.
None
Version notes
Version notes about the dataset.
Is version of another dataset
Link to dataset that it is a version of.
Other versions
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Provenance Text
Provenance Text of the data.
Conservation Ontario
Provenance URL
Provenance URL of the data.
Temporal resolution
Describes how granular the date/time data in the dataset is.
GeoSpatial resolution in meters
Describes how granular (in meters) geospatial data is in the dataset.
GeoSpatial resolution (in regions)
Describes how granular (in regions) geospatial data is in the dataset.
Field Value
Indigenous Community Permission
Who holds the Indigenous Community Permission. Who to contact regarding access to a dataset that has data about Indigenous communities.
Community Permission
Community permission (who gave permission).
The Indigenous communities the dataset is about
Indigenous communities from which data is derived.
Field Value
Number of data rows
If tabular dataset, total number of rows.
1
Number of data columns
If tabular dataset, total number of unique columns.
31
Number of data cells
If tabular dataset, total number of cells with data.
31
Number of data relations
If RDF dataset, total number of triples.
Number of entities
If RDF dataset, total number of entities.
Number of data properties
If RDF dataset, total number of unique properties used by the triples.
Data quality
Describes the quality of the data in the dataset.
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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