ORM Vital Signs: Tracking Change on the Oak Ridges Moraine

For all but the longest-standing residents of the Oak Ridges Moraine (ORM), it’s easy to believe that the landscape is largely unchanged. Conservation authorities and regional forests still protect core habitat and watersheds, the kettles and drumlins still roll away into the horizon, and the headwaters still cut through clay and sand on their way to Lake Ontario and Lake Simcoe.

What we don’t see, from any one vantage point, is how much has changed over the last 25 years: palatial homes strewn through the countryside, clay berms concealing massive aggregate pits, roads and pipes fragmenting natural linkage areas, and the relentless spread of urban sprawl.

Using new mapping tools—and in the absence of provincial tracking—ORM Vital Signs is STORM’s effort to showcase this slow and silent diminishing of the ORM’s vitality. In the absence of a provincial monitoring framework, ORM Vital Signs tracks how the moraine’s forests and landforms have changed since 2000 and makes the evidence available to communities in need when government policies and enforcement fall short.

Tracking Cumulative Effects

Over the next several months, we’ll be launching Moraine Vital Signs with two core maps. The first uses satellite imagery to calculate the Normalized Difference Vegetation Index (NDVI) for six summers—2000, 2005, 2010, 2015, 2020 and 2025—producing a time-lapse of canopy health and density over a full quarter century. On a single council agenda, a rezoning or site plan can look minor; on a twenty-five-year map, repeated “minor” decisions show up as thinning cover, fragments of woodland breaking apart, and natural areas retreating from the edges of roads, golf courses and settlement areas. NDVI does not replace fieldwork or hydrological modelling, but it does something our politics badly need: it creates a shared, visual baseline to help illustrate the cumulative impacts of policy decisions.

The second dataset provides terrain change analysis by looking below the canopy at the shape of the landform itself. By comparing digital elevation models (DEMs) from different years, ORM Vital Signs can see where the ORM’s surface has been cut, filled or flattened. This matters because the ORM is not a generic upland; it is a complex glacial landform whose hummocks, kettles and slopes control how water is stored, filtered and released. The Oak Ridges Moraine Conservation Plan’s landform conservation policies were written to stop exactly the kind of deep regrading that undermines those functions, yet it is very difficult for communities to prove that a hill has been lowered five metres over fifteen years, or that a valley has been quietly filled under the banner of “site alteration.” Terrain-change analysis gives us a tool to look back over time to correlate site-specific changes in the ORM’s surface landform with real-time council decisions and approvals to explore policy gaps and enforcement issues.

Vegetation and landform tracking are the first two vital signs, but not the last. As the program grows, STORM expects to add additional indicators built from provincial and conservation authority datasets: land-cover time series such as the Ontario Land Cover Compilation, which distinguishes forest, wetland, agriculture and urban land uses across southern Ontario; long-term surface water quality data from the Provincial Water Quality Monitoring Network, which tracks nutrients, metals and chloride in streams at hundreds of stations; and groundwater level and chemistry trends from the Oak Ridges Moraine Groundwater Program. Together with existing watershed report cards on forest condition, wetland cover, and stream health, these datasets can be layered into ORM Vital Signs over time, turning it into a fuller diagnostic panel representing the ORM’s ecological and hydrological health.

Planning Accountability

Since Ontario’s conservation authorities were stripped of their duty to review the technical aspects of natural heritage evaluations submitted by developers, municipal and tribunal decisions have often been informed by qualitative opinions.

When a municipality considers expanding a settlement boundary, when a major recreation proposal lands on the ORM, when a tribunal is told that impacts will be “minor” or “mitigated,” we need more than opinion. We need to be able to show—with data, maps and time series—how similar changes have played out on the landscape over the last quarter-century.

That is the core purpose of ORM Vital Signs: providing communities access to system-wide evidence to inform and reinforce best planning practices.

Built by the Next Generation

There is another quiet story inside this project. Much of the heavy lifting on ORM Vital Signs—the data processing, the map building, the careful comparison of years and datasets—is being carried out by University of Toronto Mississauga interns Sarah Saleem and Joshua Barci.

Their work is a reminder that the future of the ORM will not be decided in cabinet rooms or board chambers. The future of the ORM depends on training and supporting the next generation of planners, geographers and advocates to protect this landform in perpetuity. This will require an intimate relationship with the land, access to innovative tools, and the knowledge to insist that our planning decisions are tested against what is really happening on the land.

Built for Generations to Come

No single map will save the Oak Ridges Moraine. But without clear, public, repeatable ways to see how it is changing, our arguments are toothless. ORM Vital Signs is one way to keep the ORM’s real condition in view, and to make sure that every new decision is measured against what has already been lost, and what still can be saved.

Over the coming months, STORM will begin releasing the first ORM Vital Signs datasets and maps, starting with long-term vegetation and landform change. If you live on or near the ORM, watch for these releases, share them with your councillor, and plan to bring them into the conversation the next time someone says a proposal will have “no impact.”