Caledon warehouse project exposes environmental impacts of mismatched development
Feature Image Tribal Partners

Caledon warehouse project exposes environmental impacts of mismatched development

The Toronto and Region Conservation Authority is sticking to its position, claiming the shifting of a stream within the provincially protected Greenbelt to make way for a massive warehouse in Caledon will be “ecologically beneficial”, despite a report from its own staff detailing the potential problems around altering a natural watercourse. 

In 2021, a Minister’s Zoning Order (MZO) was requested by the Town of Caledon to expedite the planning process for a 2.2-million-square-foot warehouse at Dixie Road and Mayfield Road. The request—which allows the provincial housing minister to approve projects and bypass local, publicly driven planning processes—faced widespread backlash from environmentalists and concerned citizens.

To make space for the warehouse, engineers are planning to divert a tributary of the Humber River that runs directly through the property. According to the Ministry of Natural Resources and Forestry, the site at 12035 Dixie Road is significant habitat for amphibians and waterfowl, including the endangered redside dace, a small fish some aquatic biologists fear is facing extirpation in Ontario due to the ongoing threats from urbanization.

It was a shock to many when then councillor and chair of the TRCA Jennifer Innis, said the alteration of the stream’s natural course would be ecologically beneficial, claiming, “the environment will benefit from the work that will be done on this site.” 

Tribal Partners, the proponent behind the warehouse project, claim that 10-to-30-metre buffers around woodlands and waterways on the site will protect them from the impacts of warehouse activity. It’s another questionable claim.

Wetland ecologist and associate professor at the University of Waterloo, Rebecca Rooney, told The Pointer’s What’s the Point podcast that there is no ideal barrier between urbanization and sensitive natural spaces. 

“Certainly farther is better. Bigger buffers around wetlands will result in healthier wetlands,” she said. “But of course, we have to draw a boundary somewhere.”

Rooney said that traditionally a 30-metre-to-100-metre buffer is considered sufficient by consultants, but studies have shown that even with 500-metre buffers, commercial, agricultural, residential and industrial development has an impact on the integrity of nearby wetlands. 

“Wetlands are connected to their landscape. And so if you put a parking lot right up to the edge of the water, that’s going to have a huge impact on the integrity of the wetland, on the wildlife that uses it, on the water quality, even the ability of that wetland to function,” Rooney said. 

The TRCA says the wetlands surrounding the site are far enough away and will not be impacted.

“The wetlands are well over 100 metres from the development limit, are hydraulically separated from the development, and no impacts to the wetlands are anticipated as a result,” the TRCA states. 

This does not appear to take into account that the impacts of the warehouse site do not end at the property line, as pollution, and truck traffic will extend far behind these imaginary lines. One particularly damaging impact will be the increased presence of road salt in the area, which will be required to keep the large concrete pad of the trucking lanes, and the roads surrounding the site clear for truck traffic during the winter months. 

Innis, who was a pro-development councillor, pushing projects such as the warehouse and the 413 Highway, campaigned to become the town’s mayor in the 2022 municipal election but was defeated by Annette Groves after residents questioned the former TRCA chair’s track record on protecting Caledon’s vast natural landscape.

When asked in 2021, the TRCA repeated the claims made by Innis, noting the widening and lengthening of the stream would provide better fish habitat and improve water flow. 

To get an update on the project’s status, The Pointer reached out to the TRCA again to see if it still held the same position following Innis’s departure. The board vote that made Innis chair of the TRCA in 2019 was surrounded by controversy, with members admitting to being lobbied by representatives from the development industry, and assertions from the previous chair that those around the board table who voted for Innis had the interests of the development industry, not the environment, in mind when they allegedly pushed for her to take control of the agency. At the time, Innis denied knowing why people lobbied board members to appoint her as chair. 

“It remains the opinion of TRCA staff that the watercourse realignment and enhancement will provide a net ecological benefit,” a spokesperson for the TRCA told The Pointer in an email statement. “The enhancement proposed would introduce riparian wetland features, better watercourse characteristics, and would allow for fish passage. It should be noted that realignments have been approved and implemented both up and downstream of the site.”

The TRCA’s support for diverting the stream is questionable given the organization’s mandate of conserving southern Ontario’s delicate ecosystem. It also appears to look at the stream divergence in isolation. The TRCA states “The watercourse was ill-defined, historically altered through past farming practices, and did not allow for fish passage to headwater reaches,” and therefore concludes that realigning the watercourse would be a net benefit. But when considering the 2.2-million-square-foot warehouse that will be constructed in close proximity to this waterway, any “improvements” made are dwarfed by the negative impacts of such industrial uses, including contaminant runoff, noise and light pollution, and a myriad of other negative effects that come when farmland and greenspace is converted for urban uses. 

The conclusion also does not appear to take into account the uncertainty that arises any time human action attempts to change the natural state of a given ecosystem. 

“All river relocation channels present an artificial discontinuity between natural sections of a river. This artificial channel seldom has the identical physical characteristics of the adjoining upstream and downstream reaches,” geomorphologists Alissa Flatley, Ian Rutherfurd and Ross Hardie wrote in the journal, Water. “As such, river relocation channels can be considered as large-scale geomorphic experiments.”

A recent report from the TRCA further illustrates this uncertainty. Even when the organization’s experts rely on scientific best practices for changing and altering waterways (the TRCA is the largest watershed conservation organization in Canada and considered a global leader in habitat restoration) the outcomes and planned “benefits” do not always come to fruition. The March report to the conservation authorities’ Regional Watershed Alliance details numerous instances where river paths were changed in the Region of Peel through practices of channelization and armouring, thought to improve water flow. 

“The realignment (straightening) of watercourses accompanied filling within valleylands to facilitate development, a practice that is no longer permitted due to negative environmental impacts. Current knowledge has shown that channelization can increase the chances of downstream flooding and erosion,” the report states. “These channels are now contributing to erosion and streambank failure, which can raise the risk of local flooding and damage to adjacent properties and infrastructure.”

The stream altering processes that were used were either less common (channelization and armouring) or banned (straightening), when they were described as ecologically stable. The TRCA determined the watercourse that runs through 12035 Dixie Road is ill-defined and was altered in the past due to farming practices. But as the examples from Brampton show, there is no guarantee that further manipulation of the stream will have the claimed benefits.



The site plan for 12035 Dixie Road shows how close the warehouse will be to the realigned stream and the Greenbelt, designated as Environmental Area in the top left corner.

(Tribal Partners)


When the MZO to trigger the project without proper public consultation and work by the local government was submitted, council members seemed unphased by the potential environmental impact of the watercourse manipulation on sensitive habitats. The only member opposed to the motion was Ian Sinclair, the former regional councillor for Ward 1. He said council was being rushed into a decision that would allow the developers to skirt by important aspects of the development process. Former councillor and current Mayor Annette Groves, known through her voting record as being environmentally conscious, was absent when the October 2021 decision was made.

The rest of council voted in favour of the motion. None questioned whether the development would be sustainable. 


In March 2022, the Region of Peel voted to expand its urban boundary by 11,000 acres for residential and employment development, including the site at 12035 Dixie Road.

(Region of Peel)


The TRCA seems unconcerned about the immediate proximity of the warehouse to sensitive surrounding ecosystems.

“The wetlands are well over 100 metres from the development limit, are hydraulically separated from the development, and no impacts to the wetlands are anticipated as a result,” the TRCA states. 

This does not appear to take into account that the impacts of the warehouse site do not end at the property line, as pollution, and truck traffic will extend far behind these imaginary lines. One particularly damaging potential impact will be the increased presence of road salt in the area, which will be required to keep the large concrete trucking lanes and roads surrounding the site clear for truck traffic during the winter months. 

A previous investigation by The Pointer of the 11 monitoring stations maintained by the Credit Valley Conservation Authority (CVC) in the months of June and July, when concentrations of chloride, a component of road salt, are often lower, found levels at the majority of the stations were above those that cause acute harm to aquatic life. Levels above 640 milligrams per litre are considered enough to cause acute harm. Some of the figures were nearly three times as high. Road salt is just one of the potential threats that can stem from warehouse activity that will ultimately put more trucks on the road. 

In the last term of council, truck traffic, particularly in the community of Bolton, was an issue that repeatedly came to the table. Former mayor Allan Thompson and Innis were supporters of the creation of a freight village in Bolton — a massive transportation and logistics corridor that would host commercial trucking activity for the distribution of goods. The proposal was supported despite the inevitable increase in air pollution and other environmental impacts, and concerns from residents in opposition to living in and around a freight village. 

In early 2020, Groves, who was opposed to turning the Bolton area into a freight village dominated by large commercial trucks around the clock, accused Thompson of making a request to the Province to expand employment lands in Bolton in order to build the freight village. Prior to the 2022 municipal election, Groves garnered support from Caledon residents after promising to get trucks off the roads and out of the villages and hamlets that make the municipality unique.

Groves told The Pointer she needs more information on the project and intends to ask staff for an update and some clarity. 

The MZO for the development at 12035 Dixie Road was approved in March 2022. According to Tribal Partners’ website, construction at the site was supposed to begin last year. The Pointer asked what caused the delay but Tribal Partners did not respond.



Email: [email protected]

Twitter: @rachelnadia_

COVID-19 is impacting all Canadians. At a time when vital public information is needed by everyone, The Pointer has taken down our paywall on all stories relating to the pandemic and those of public interest to ensure every resident of Brampton and Mississauga has access to the facts. For those who are able, we encourage you to consider a subscription. This will help us report on important public interest issues the community needs to know about now more than ever. You can register for a 30-day free trial HERE. Thereafter, The Pointer will charge $10 a month and you can cancel any time right on the website. Thank you

Submit a correction about this story