After more than 15 years of delays, federal laws now prohibit activities that would destroy the habitat of the endangered Redside Dace. That’s great news for Redside Dace, and very bad news for well-connected developers who’ve been planning sprawl subdivisions, warehouses, and taxpayer-funded highways through Dace habitats in the upper reaches of the Humber River, Carruthers Creek, Duffins Creek and Rouge River.

As required by the Endangered Species Act and the Redside Dace Recovery Strategy and Action Plan, the Critical Habitat of the Redside Dace (Clinostomus elongatus) Order: SOR/2025-4 prohibits anyone from doing anything that would destroy any of the habitat value of the mapped rivers, creeks and tributaries that Redside dace depends on. Since the Humber River’s upper reaches and tributaries are identified as critical habitat in the Recovery Strategy, it’s now clearly illegal to build the parts of Highway 413 that cross them.

redside dace
Redside Dace

The Protection Order also prohibits highway and sprawl construction currently being planned within the larger watersheds that feed Redside Dace habitats in the Humber River, Carruthers Creek and other waterways. That is because the Recovery Strategy makes it clear that activities including any “large increase in impervious surfaces” would constitute destruction of critical habitats even if they take place outside of the critical habitat itself. The Recovery Strategy explains that paved surfaces would destroy critical habitat, even if built outside it, because the Redside Dace is highly sensitive to the changes those paved surfaces always bring, including warmer water, lower oxygen, murky water, and changes in stream flow.

Of particular note the Habitat Protection Order seems to rule out:

  • Provincial plans to bulldoze and pave large areas of the Humber, East Humber and West Humber watersheds north of Brampton into commercial and residential sprawl.
  • Provincial plans to turn the land which surrounds the upper reaches of the Carruthers Creek into a new leapfrog sprawl development, and where the recent Toronto Region Conservation Authority’s Watershed Plan determined that development would “likely resul[t] in the loss of Redside Dace”.
  • Any non-agricultural or natural cover development of the former Pickering “airport lands” which surround the headwaters of the Duffins Creek.

All of this is great news for the Redside Dace, and for the fight to curb the wasteful sprawl that has been squandering Ontario’s construction capacity and causing a housing shortage.

However the danger is still real. While the Endangered Species Act and Protection Order now prohibit the destruction of these critical redside dace habitats, the federal government might intentionally decide to allow the extirpation of this beloved endangered species – either by issuing official permits to destroy the habitat or by intentionally failing to enforce the law, allowing harmful activities, like sprawl development to happen without a permit.

It is up to all of us to maintain pressure on the federal government, and all federal MPs, to ensure that doesn’t happen.