About the Oak Ridges Moraine
From MTM project partner-
STORM Coalition (Save the Oak Ridges Moraine) Website
www.stormcoalition.org
The Oak Ridges Moraine is a landform unique to southern Ontario.
One of Ontario's largest moraines, the Oak Ridges Moraine extends
160 kilometres from the Niagara Escarpment in the west to the
Trent River system in the east, and is on average 13 kilometres
wide. One-hundred-and-fifty metres deep, the moraine stands out
as one of the most distinct landscapes of southern Ontario. Its
height above the flat lands to the north and south, its rolling
hills and river and stream valleys and large blocks of mixed forest
provide solace and a sense of connection to the people who live,
work and play on the moraine, natural and wild habitat for flora
and fauna, and untapped recreational opportunities.
However, the Oak Ridges Moraine is more than just a beautiful
landform feature with its breathtaking vistas, rolling hills,
wooded valleys and 'kettle' lakes. Its most precious feature lies
hidden below the ground surface.
One of the moraine's most important functions is as a water recharge/discharge
area - sustaining the health of the many watersheds, which originate
in the moraine and directly providing drinking water to over 250,000
people. It has been described as southern Ontario's rain barrel
- its permeable sands and gravels absorb and collect precipitation,
which slowly recharge the deep aquifers below the ground.
These sand and gravel aquifers store, filter and release this
groundwater to over 65 watercourses flowing north and south into
Georgian Bay, Lakes Simcoe, Scugog, Rice and Ontario. At the same
time, unprecedented human exploitation of this groundwater places
the moraine in a precarious ecological position.
The 1991 Oak Ridges Moraine Planning Study, which began as a
tightly focused land use planning exercise, became a catalyst
for innovative water resource studies. The Ontario Ministry of
Natural Resources, through the planning study, undertook a broad
hydrogeological review of the Oak Ridges Moraine. This led to
the involvement of the Ontario Geological Survey and the Ontario
Ministry of the Environment in developing detailed geological
and hydrogeological mapping. In 1993, the Geological Survey of
Canada initiated an extensive five-year Oak Ridges Moraine study.
The result of this collaborative work is an extensive 'regional
scale' understanding of the Oak Ridges Moraine, exceptional by
Canadian standards.
Despite the focus of the Geological Survey of Canada and its
call for integration of land- use planning and groundwater management,
municipalities and the provincial government continued to carry
on with business as usual - processing applications for development
and official plan amendments in the absence of a comprehensive
groundwater management strategy. Land-use changes,primarily the
building of residential subdivisions, the construction of roads
and the paving of parking lots increase the imperviousness of
the ground surface, stopping water from entering the hydrologic
cycle. Consequently, this surface runoff results in dramatic increases
in wet weather flows of the headwater streams on the moraine causing
erosion and degradation of these fragile systems. Urban and rural
contaminants entering the ground today can remain undetected for
many decades given the excruciatingly slow movement of water through
the ground. Water-taking, associated with these new land uses,
further exacerbates the pressure on the resource. Not only is
precipitation blocked from entering the ground but more water
is being removed. Municipal water supplies, golf courses and commercial
water-bottling companies have, by necessity, began to 'go deeper'
into the moraine to find adequate quantities of drinkable and
usable water.
We have learned over the past several years that we must proceed
cautiously - how we use the moraine's land surface and its water
resources can affect the deep regional groundwater flow systems,
which are integral to the ecosystem health of south-central Ontario.
The Oak Ridges Moraine:
A Provincial Treasure
Soaring north from Lake Ontario's northern shoreline, the landscape
below leaves behind the tall office buildings and dense residential
streets of Toronto's heart, passes over suburban sprawl of subdivision
and industrial parks and development coalesces along major roads
and unseen pipelines that penetrate the countryside. The land
below is flat, dissected by river valleys that deepen as they
reach further into their headwaters. And then, abruptly, the country
changes from flat till plains to rolling hills and valleys; splashes
of green forests and blue waters replacing the greys and blacks
of pavement and rooftops. With a shift in perception through the
lens of time, you can almost see the massive glacial rent in the
ice sheet filling up with icy waters and a millennia worth of
sand and gravel and boulders; these are the early days of the
interlobate Oak Ridges Moraine, arcing like a huge eyebrow above
the eye of Canada's largest city.
Seen directly from above the first and most startling impression
is "this is where the rivers begin!" All along the ridge
of this regional surface water divide are many finger patterns
of tiny headwater streams bubbling out of the ground in seeps
and swales and springs. These trickles of water join forces, delivering
cold clean water to the many rivers and streams that flow north
and south from the moraine. The river valleys are well forested,
providing living corridors along which animals travel. Wetlands
and kettle lakes along the length of the watersheds are home to
hundreds of species of birds and amphibians and provide needed
watering holes for all kinds of wildlife.
Deep within the ground is the true treasure of the moraine -
thick layers of sand and gravel many hundreds of metres from surface
to bedrock. The waters in these aquifers span thousands of years
in age; on the surface the water was yesterday's rain but deep
deep down the water held in trust was once glacial ice. This is
truly the lifeblood of the region, providing water to people,
to rivers and to the oceans. It is these waters that may help
us survive the warming of the years to come.
Strung along the rivers of the moraine are historic towns that
show similar patterns of conurbation - the classic village center
ringed by modern subdivisions and schools and baseball diamonds.
Up or downstream are remains of dams signifying how important
the fast flowing rivers once were to the economy of a century
ago. Today, the millponds perform a different role of attracting
birds and wildlife, bringing eco-tourist dollars to these struggling
centers.
The second startling impression is the sight of a long and narrow
urban band stretching from the south to the north straight through
the hills and valleys. The Big Pipe decision decades ago helped
to bury the precious tributaries under acres of pavement and to
bring thousands of people up to the moraine. It was here where
the moraine was almost cut in half by development and it was here
where the battle for the moraine was staged and won. Through provincial
intervention, this significant section of the moraine has been
placed in the public trust, thus preserving a vital link in the
regional natural heritage system.
Fields of corn, hay, soybean, horses and cattle seem to drape
themselves around large garrulous old forests. Decades of restoration
efforts to re-connect the forest fragments are evident in the
thousands of acres of pine plantations, the hedgerow artifacts
and the newly planted saplings put there by school children. It's
obvious now that many of these marginal farm fields high on the
ridge should never have been cleared back in the early days of
First Contact - like long lost friends the newly-planted roots
re-secure the fine sands and silts and hold them close. More productive
farms on the north and south slopes are thriving and contribute
strongly to the economy of the area - tractors move more slowly
up and down the moraine hills than they do on the flat fields
to the north and south. The natural curves of the rivers and forest
edges are rudely pushed aside by the long linear slashes of roads
first built to bring the Europeans to this land to conquer. Like
ribbons of death, the new four lane highways do their best to
stop the genetic movement of nature. But nature's resiliency proves
too strong as plants and animals continue to move about the length
of the moraine.
Yes, sprawl is nibbling at the southern front of the moraine
and sprawl has been temporarily tamed. It will roar again in the
future and its threat will never totally disappear. But for now
development has been beaten back to the boardroom.
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