Watershed, Primary

A watershed, also known as a catchment basin, includes all of the land that is drained by a watercourse and its tributaries.

Watersheds are split into 3 categories: primary, secondary and tertiary.

Ontario has 3 primary watersheds:

  • Great Lakes - St. Lawrence
  • Southwestern Hudson Bay
  • Nelson River

These divisions are based on the federal framework originally known as the Water Resources Index Inventory Filing System

Instructions for downloading this dataset:

  • select the link below and scroll down the metadata record page until you find Transfer Options in the Distribution Information section
  • select the link beside the Data for download label
  • you must provide your name, organization and email address in order to access the dataset

This product requires the use of GIS software.

*[GIS]: geographic information system


Ontario's Open Data Team opengov@ontario.ca


Data Available

The data described here is available for you to use. [Learn more]
[See the licence for how you're allowed to use this data.]

Covers 2002-08-01 - 2009-05-01

Supporting Files

Additional Info

Field Value
Geographic coverage
Geography Breakdown None
Source URL/Address
Author Email
Maintainer branch
Last Validated Date 2020-04-14
Update frequency As required
Access instructions