Catchment boundaries as published by school districts, made topologically valid and linked into feeder chains.
What cleaning means here
Published catchment files are usually digitised from paper or maintained in a system that does not enforce topology. The common defects are slivers where two boundaries were drawn independently, gaps where no catchment covers a strip of land, and overlaps where two schools both claim an area.
Each is resolved and recorded. The layer carries a cleaning_action field so you can see what was changed on any polygon, and the original geometry is retained in a parallel table.
Feeder links
Elementary catchments are linked to the secondary catchments they feed, using the district’s stated progression where published and a spatial overlap threshold where not. Where an elementary catchment splits across two secondaries, both links are recorded with the share of area in each.
What this is not
These are the boundaries districts published, not a judgement about where students should attend. Districts operate choice programs, French immersion catchments, and transfer policies that this layer does not model. Address-to-school assignment is a district decision and this layer will not always predict it.
Vintage
Catchments follow the school year, not the calendar quarter. The current file is 2026-27. Boundary reviews typically conclude in spring, so the file is refreshed once a year with mid-year corrections as districts issue them.