The Kawartha Watershed


The Kawartha watershed is a unique landscape that holds vast wetlands, and long meandering rivers that flow to and from big lakes along the Trent-Severn Waterway. Agriculture thrives on rich soils and clean water, picturesque rural communities dot the landscape, and conservation and natural areas protect significant natural heritage. All of our programs and services support the protection of this unique watershed in Ontario.

Map of the Kawartha Watershed

To learn more about  Kawartha Watershed


Science and the Oak Ridges Moraine

oakloc.jpg       Research on the hydrology of the Oak Ridges Moraine had begun by 1970, with efforts to understand the significance of the aquifer as a recharge source for Lake Simcoe and Lake Ontario (Haefeli 1970). Only in the last decade, however, has there been a focus on the potential impact of urban development on the moraine, and ultimately on Great Lakes water quality. Much of the research on the moraine has taken place at two centres: the Geological Survey of Canada, and the University of Toronto Groundwater Research Group. Several consulting firms have also made significant contributions, including work for the Oak Ridges Moraine Technical Working Committee, or for private developers.

Learn more about Case Study: The Oak Ridges Moraine

Oak Ridges Moraine: land use designations

This data set was created to provide land use information on the Oak Ridges Moraine and is the basis for Ontario Regulation 140/02.

The data was digitized at 1:10,000 or better using 0.5 metre air photos, MNR, DMTI, Upper and Lower-tier Official Plans and digital vector layers.

To view, click the link below:

Oak Ridges Moraine Land And Trust

When the glaciers of the Wisconsin ice age retreated some 11,000 years ago they left the giant ridge of sediment we now know as the Oak Ridges Moraine. Southern Ontario was a bleak and chilly place.

Woolly Mammoths roamed the perimeter of giant lakes, many times larger than our current “Great Lakes”. At this time, the Oak Ridges Moraine (ORM) would have looked like arctic tundra, with only a few small coniferous trees and sparse vegetation able to grow in the stark rocky landscape.

The forests of the Moraine grew and changed, ultimately evolving into a complex ecosystem that sustained a diversity of wildlife under a towering canopy of oaks, sugar maples, beech, and many other tree species.

The Moraine has been shaped by the forces of nature and the forces of human occupation. What happens in the future will depend on understanding the past and by acting now to find a course of sustainability.

Want to learn more about the history of Oak Ridges Moraine?

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Quick Facts and Figures About Oak Ridges Moraine

Small Map of the Oak Ridges Moraine

The Moraine has an enormous amount of biodiversity. There are:

  • 1,171 plant species
  • 125 species of moss
  • 166 breeding bird species (and more through migratory seasons)
  • 30 species of reptiles and amphibians
  • 51 mammal species
  • 73 fish species
  • 74 species of butterflies
  • 70 dragonflies and damselfly species
  • 88 species are provincial or national species at risk and 466 are moraine rare (Canada as a whole has 71,500 species of plants and animals, with approximately 422 species at risk)

There are 72 life and earth science Areas of Natural and Scientific Interest (ANSI’s) covering 15% of the moraine and 82 Environmentally Significant Areas (ESAs)

For more information about the Oak Ridges Moraine


Interesting Physical Facts Of Oak Ridges Moraine


  • Oak Ridges Moraine stretches 160 kilometers from east of Mono Mills at the Niagara Escarpment to Castleton, north each of Cobourg
  • North and south of the Moraine is ‘narrowest’ ( < ½ km ) at Bewedley on the west end of Rice Lake and (just about ½ km) at Simcoe Street north of Oshawa. An area of major concern for connectivity of the Moraine occurs within Richmond Hill at Yonge Street where the only undeveloped ‘natural linkage area’ is considerably less than ½ km in the area currently referred to as Corridor Park
  • The Moraine covers a geographic area of 1900 square kilometers approximately 1/3 of the size of Prince Edward Island
  • 90% of the Moraine is in private ownership
  • 60% of the Moraine is in the Greater Toronto Area, 20% in Northumberland County, 7% in the city of Kawartha Lakes, 5% in Simcoe County, 3% in Peterborough County and 1% in Dufferin County
  • 32% of the Moraine is covered in upland forests and is one of six recognized areas for forest bird diversity in southern Ontario
  • 5% of the Moraine is wetlands

For more information of Oak Ridges Moraine, visit Oak Ridges Moraine Land Trust Website! (

Research on the moraine

In 1829, John Bigsby conducted the first investigation of the moraine. He noted the elevation, and styled the area Oak Ridge, identifying the portion of moraine north of Toronto. The moraine’s extent was not established until 1863 when William Logan conducted the Geological Survey of Canada.

Taylor formally defined the landform as the Oak Ridges Moraine in 1913. He described its extent to be from King and Maple in the west to the Trent River in the east. He also proposed that its origin was overlapping, interlobate glaciation retreat, between the Lake Ontario Lobe and the older Lake Simcoe Lobe. This has become the accepted explanation for the moraine’s development, through research in the 1970s suggested the moraine may not be interlobate.

Research conducted in the 1990s revealed that the moraine has multiple origins: its eastern area has subglacial depositions (Gorrell and McCrae, 1993); early parts of the moraine were deposited in an esker (Brennand and Shaw, 1994); and that the moraine is not continuous, but is composed of multiple depositional environments: subglacial, ice-marginal and proglacial lacustrine (Barnett et al., 1998).

Current research efforts on the moraine are quite extensive. Because of the political implications of development on the moraine, and because its aquifers are a source of potable water for numerous communities, both federal and provincial governments have invested resources towards research on the moraine. The Geological Survey of Canada and Ontario Geological Survey both investigate hydrostratigraphy and hydrology throughout the moraine.

Palaeo-Indian hunter-gatherers were in this area between 10,000 – 7000 BC. The oldest artifact found in what is now Richmond Hill, Ontario, from these people, was a stone scraper about 40 mm long, at the Mortson Site, near Leslie Street and 19th Avenue. Other artifacts were found in a settlement site on the eastern shore of Lake Wilcox.

Archaic Iroquois artifacts c. 1800 BC have also been found at the Silver Stream site, near the headwaters of the Rouge River on Leslie Street just north of Major Mackenzie Drive, and at the Esox site, on the eastern shore of Lake Wilcox.