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Thames
River Quality
Introduction - Why Is
This Topic Of Interest?
What Are The Impacts To Water Quality?
Thames River Indicators
New! 2009 Fish Movement
Research at Springbank Dam
Introduction
- Why Is This Topic Of Interest?
The Thames River is one of the largest and most
biologically diverse rivers in Ontario. The
river is arguably the City of London’s most
significant natural feature and an environmental
asset. It flows through the centre of the city
and is used by thousands of residents and
tourists alike. It is used for a number of
purposes in the London area including natural
habitat, recreation, sport fishing, agricultural
irrigation, commercial / industrial and
residential water supply and wastewater
discharge.
The Thames River doesn’t begin in London; it
originates farther upstream in wetlands north of
Stratford and east of Woodstock. It flows
through several smaller communities and agricultural lands before
entering the city at Fanshawe Lake (North
Branch) and near Airport Road (South Branch).
The two river branches meet at the Forks and
form the Main Channel that continues to flow out
of the city past Kilworth, downstream to
Chatham and eventually outlets into Lake St. Clair.
Historically, the river is one of the main
reasons the city was settled where it is, at the
Forks of the Thames. The multi-purpose Thames
Trail Parkway now winds along most of the river, providing multi-purpose recreational trails,
parks, wildlife habitat and other natural
amenities. The Thames River was designated a
Canadian Heritage River in 2000 to highlight the
natural and cultural heritage found along its
banks. Regarding water quality, the watercourse
faces many pressures and stresses attributed to
both the agricultural and urban land uses and
due to a changing climate regime. Warmer
temperatures and more frequent and intense
rainfalls are reshaping the river from what it
once was.
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What Are The Impacts To Water Quality?
Water quality of the river has seen
fluctuations. Degradation of the quality of the
river from its natural state began as the area
became settled. As more land was cleared for
agriculture and as urbanization progressed, the
quality of water continued to deteriorate.
Causes for degradation in river quality in the
London area could be traced to both sources
upstream of the city, as well as sources within
the city, including industry, storm water runoff
and pollution control plant discharges.
The City of London, as well as other partners,
have been monitoring the water quality of the
Thames River through the city for almost 40
years. In the past, low dissolved oxygen
concentrations and elevated levels of bacteria,
ammonia, total phosphorus and biological oxygen
demand were common occurrences in the river.
Despite the dramatic growth of the city in both
developed area and population over these past 40
years, there has been an overall improvement in
river quality. The reasons for this are many and
include:
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Improved performance of the City’s pollution
control plants,
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Implementation of storm water management
controls for new developments in the city,
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The separation of combined sewers in older
portions of the city,
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Improved agricultural practices upstream of the
city, and
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Greater public awareness of environmental issues
and stewardship opportunities.
Monitoring of water quality is critical to
ensure we know what impact various pressures
have on the river and to be able to wisely
manage this feature. This will be for the
benefit of all who share in using and
a
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2009 Fish
Movement Research at Springbank Dam
View the
full 2009 report
here.
This
report (Biotactic Incorporated, 2009) is the
second year of a
multi-year, post-construction fish
monitoring effort being undertaken as
part of the Springbank Dam
Rehabilitation Project. Repair to the
gates after flood damage in 2000
necessitated fish monitoring to ensure
status quo conditions in the river at
the dam were maintained or enhanced. The
2009 report provides a comparison with
pre-construction, baseline research that
was completed in 2006 and with
post-construction, 2008 monitoring. In
each monitoring year,
multiple species of fish were tracked to
monitor their behaviour in the vicinity
of Springbank Dam during open flow
conditions.
View
the full 2008 report
here.
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Thames
River - Quick Facts
From the Clouds to the River
(pdf poster)
The Thames River is about 270 km in length
with London situated in the upper half.
It takes about 7 to 10 days for water to
travel from one end of the river to the other
(Tavistock to Lake St. Clair). In London, it
takes about 1 day to flow from one side of the
city to the other.
The length of the London portion of the Thames
River (including both the North and South
branches) is 43 km. In addition there are the
tributary creeks, such as Stoney, Medway,
Pottersburg and Dingman creeks.
The River is home to approximately 90 species
of fish (many considered species-at- risk), 220
species of vascular plants and over 26 species
of freshwater mussels (or clams).
In the early 1900’s, it was common to dump
material and garbage into the river (metal,
coal tar). Today, the implications of these
actions are well known, the actions no longer
permitted and many of these sites have been
successfully cleaned up.
The Thames River was one of the first rivers
formed after the retreat of the last glacier
in Ontario.
The Water Survey of Canada installed a flow
monitoring station on the Thames at Byron in
1916.
On average, only 40% of the precipitation runs
off into the Thames River to Lake St. Clair
each year (the rest evaporates, infiltrates
the soil, or is used by
vegetation).
Most, but not all of London drains to the
Thames River. The southerly 16% of the city
drains south to Kettle Creek.
The Thames River was also known as Antler
River by the First Nations and La Tranchée, or
“trench” by the French Canadians.
Floods along the river in London were greatest
in 1883, 1937, 1947, 1977, and 2000. The 1937
flood was the largest, reaching flows 120 times
greater than average.
Did you know
that you can get more information including
annual summaries of water quality reports from
the City web site?
Click here for link.
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