Oak Ridges Moraine

`The Oak Ridges Moraine stretches 160 kilometres from the Niagara Escarpment almost to the Trent River. About 65% of it is within the GTA. It rises up to 300 metres above Lake Ontario and contains deposits of sand and gravel up to 200 metres thick. ¸ Today, the Oak Ridges Moraine is the prominent ridge north of Lake Ontario. The ridge influences the flow of surface and groundwater, and local climate in the GTA.

Rain and snow that fall onto the Oak Ridges Moraine soak into the ground to replenish large reservoirs of groundwater that supply drinking water for over 200 000 people. This is because moraine sands and gravels allow water to infiltrate more rapidly and in much greater amounts per unit area than the surrounding, less permeable till plains. In addition, depressions called kettles capture water rather than allowing it to run off over the surface. Hence, there are few flowing streams on the moraine. Instead, water seeps into the depths of the moraine until it reaches a less permeable layer. It then begins to move sideways to emerge as springs or wetlands along the lower slopes. These springs are the headwaters of over 60% of the watersheds in the GTA.

Source: Natural Resources Canada

One of the Oak Ridges Moraine’s most important functions is that it acts as a water recharge and discharge system. Permeable sands and gravel absorb and collect rain and melted snow, which then slowly filter into the deep aquifers, or wet underground layers of water-bearing permeable rock or unconsolidated materials, below the ground. This groundwater is then used in private and public wells across the Moraine, providing clean drinking water to more than 250,000 people. It is because of this function that the Moraine is often described as southern Ontario’s rain barrel. Source: Oak Ridges Moraine Foundation (ORMF)

Oak Ridges Moraine Fact Sheet from Oak Ridges Moraine Foundation (ORMF)

Source: Glacial meltwaters form the Oak Ridges Moraine from Natural Resources Canada.

Lesson Plan Ideas for Learning About the Oak Ridges Moraine

Explore the Oak Ridges Moraine, a prominent sand and gravel ridge north of Lake Ontario formed by glacial ice and meltwater. Use an on-line animation of a digital elevation model to fly-over the region to see its topography. Assume the roles of potential interest groups affected by a fictional plan for urban expansion on the Oak Ridges Moraine and debate your group's perspective on the issue at a "Town Hall Meeting". Build a groundwater model to learn how water and contaminants interact with layers of gravel, sand, and clay.

Lesson Plan for The Oak Ridges Moraine (PDF, 1.2) from Natural Resources Canada.

Activity 1 (PDF, 3.9 Mb) - This teacher-led discussion and self-guided internet activity provides an introduction to the formation, location and features of the Oak Ridges Moraine. Students visit the Geological Survey of Canada's Web site to explore the moraine using an animated digital elevation model.

Activity 2 (PDF, 2.7 Mb) - In groups, students read an information bulletin and a fictional case study about a proposed urban development on the Oak Ridges Moraine. Students assume the roles of potential interest groups affected by the plan and debate their perspective on the issue at a "Town Hall Meeting".

Activity 3 (PDF, 658.5 kb) - In groups, students follow instructions to build a groundwater model using a small aquarium, sand, gravel and clay. The impact of contaminants applied on the surface and in the aquifer will also be examined. Students answer questions related to their model and learn how their findings apply to the real world.

References

Oak Ridges Moraine A ridge of resources from Natural Resources Canada.

Oak Ridges Moraine Conservation Plan from the Ontario Ministry of Municipal Affairs and Housing.

Oak Ridges Moraine Biosphere Reserve Project from the Faculty of Environment at the University of Waterloo

The Role of the Media, Planning and the Oak Ridges Moraine by R. Christopher Edey, Mark Seasons & Graham Whitelaw

The Oak Ridges Moraine (STORM) Coalition is focused on protecting the ecological integrity of the Oak Ridges Moraine. Since 1989

The Oak Ridges Moraine Foundation (ORMF) is a non-profit organization mandated to preserve and enhance the Oak Ridges Moraine. In 2002, the Oak Ridges Moraine Foundation (ORMF) was started with an investment of $15 million from the Province of Ontario. Since opening its doors, the ORMF has efficiently granted $14.1 million to 177 projects and leveraged an additional $35.8 million. This means that the Province’s original $15 million was grown into $50 million worth of projects!

Oak Ridges Moraine Experience from Hunter and Associates environmental engineers and environmental and GIS specialists

Oak Ridges Moraine Hydrogeology Study 1 from Hunter and Associates environmental engineers and environmental and GIS specialists

Oak Ridges Trail Association (ORTA) maintains a 275 km of main trail, plus various side trails, have been completed. The trail starts in the west with a link to the Bruce Trail, north of Mono Mills (Hwy #9 & Airport Road), and continues through the Northumberland Forest in the east, before splitting to two gateways at Castleton and Warkworth.

Oak Ridges Moraine