2015
Why does this matter?
In Ontario, groundwater (water that discharges from springs in the
ground) is the most important factor that determines the presence of
cold and cool water streams. Groundwater discharge can cool water in
the summer and warm it in the winter. Urbanization and agricultural
drainage can reduce the amount of groundwater stored on the
landscape, which reduces this moderating influence during both summer
and winter. The increase in impervious surfaces (e.g. concrete and
pavement) resulting from urbanization not only reduces groundwater
infiltration, but also causes thermal spikes following summer
thunderstorm events from runoff into our creeks and streams.
Direct solar radiation is another factor causing streams to warm. Online ponds and stream banks without overhanging vegetation to shade
surface waters are a primary cause of excessive warming. Erosion and
sedimentation can change stream channels, making them wide, shallow
and vulnerable to increased solar radiation.
As thermal impacts increase due to urbanization, agricultural
intensification, and climate change, sensitive native cold and coolwater
species such as Brook Trout and Redside Dace are more likely to be
threatened with extirpation (local extinction) while the overall health of
these streams may become degraded.
How can you help?
•Create and maintain a shade canopy next to streams. Trees are ideal,
but even shrubs and tall grasses can help small streams. Consider
leaving an unmowed buffer of natural vegetation at locations where
manicured lawns are adjacent to a stream.
•Use rain barrels to store runoff from rooftop. This water is ideal for
watering your garden during drier periods.
•Look for opportunities to capture and store water runoff on your
property through site grading. On large properties this can mean major
works involving wetland creation but there are often other simple
and relatively easy opportunities to make a difference, even on small
urban lots (eg. rain gardens).
Take action and be part of the solution!
Be a good neighbour…Be a steward of your land.
Collectively, private landowners own the majority of natural areas in Conservation
Halton’s watershed. Each parcel of land and each individual action can make a real
difference to the health of our natural environment. Whether you own or live close to
a forest, wetland, meadow, or stream, what you do on your property can benefit or
impact these features. Good stewardship practices on your own property benefit you,
your community, and the watershed.
Conservation Halton’s Stewardship Program encourages and assists with stewardship
initiatives towards the protection, improvement, or rehabilitation of natural
areas, streams and groundwater resources on private lands. Our stewardship
program can provide technical assistance, advice and guidance, and may be able
to provide financial and volunteer assistance to private landowners for restoration,
naturalization, and environmental activities on their property. To find out more about
Conservation Halton’s Stewardship Program projects and initiatives, or to arrange a
site visit on your property with one of our Watershed Stewardship Technicians, please
call 905.336.1158 ext. 2263.
•Some new subdivisions have Low Impact Development (LID) features
built into final grading to store runoff in back lot swales to reduce
runoff and encourage groundwater recharge. If you live in one of these
areas, resist the temptation to change the drainage patterns that have
been established. Having a soggy lawn for a couple of days after a
major thunderstorm is a small price to pay for healthier streams.
Water Temperature
MONITORING
Conservation Halton’s Long-term Environmental
Monitoring Program
Conservation Halton’s Long-term Environmental Monitoring Program
(LEMP) was developed in 2005 to assess the long-term health of the
Conservation Halton watershed. The results of the program will help
guide environmental protection efforts to ensure that the watershed’s
health will be maintained or enhanced while meeting the current and
future needs of local communities.
Ecological monitoring conducted as part of Conservation Halton’s
Long-term Environmental Monitoring Program is conducted across the
entire Conservation Halton jurisdiction including the major watersheds
of Grindstone Creek, Bronte Creek and Sixteen Mile Creek as well
as fourteen smaller watersheds. It focuses on both the aquatic and
terrestrial ecosystems using biological, physical and chemical indicators
of watershed health.
This factsheet provides the details and results of the water temperature
monitoring completed by Conservation Halton over the 2015 field season.
2596 Britannia Road West
Burlington, Ontario L7P 0G3
conservationhalton.ca
• Thermal classifications were determined for 21 of the 26 deployed dataloggers. The
remaining five sites could not be analyzed because dataloggers were lost or removed
and could not be retrieved. Three stations were classified as cool, 10 as cool-warm and
eight as warm (see figure below). These temperature patterns are what one would
expect in a watershed with widespread agricultural and urban development.
• As in previous years station SXM-314, located upstream of Scotch Block reservoir, had
the coldest temperatures within the watershed. The warmest temperatures were found
at several stations on the Main and Lower Middle Branches downstream of Brittania
Road (SXM-103, SXM-151, SXM-108, SXM-435, SXM-205) and at two sites above the
Niagara Escarpment (SXM-433 and SXM-437) which are downstream of large wetlands.
• Stations GRN-7, GRN-65 and GRN-100 were classified as cool in 2015. The reaches
upstream of these stations are influenced by groundwater discharge, which helps to
moderate summer temperatures.
• The cool-warm conditions observed in the other six stations are likely the result of the
benefits of groundwater inputs being offset by thermal impacts from beaver and manmade ponds, narrow or sparsely vegetated riparian buffers, and urban stormwater.
• The highest temperature in 2015 was observed on July 29 at station SXM-108, located
downstream of the QEW (air 31.9 °C, water 30.9°C).
• The highest temperature recorded in the watershed in 2015 was at GRN-20
(downstream of Centre Road) on July 29 (air 31.9 °C, water 25.36°C ).
• Of the 17 stations previously sampled in 2013, thermal classifications at 12 did not
change. Thermal classifications increased at four locations (SXM-347, SXM-40, SXM-435
and SXM-113). The increases were slight (cool to cool-warm) and are likely due to the
warmer air temperatures observed in 2015 compared to 2013.
• Four of the 6 previously sampled stations (GRN-20, GRN-65, GRN-66, GRN-22) were
assigned a warmer thermal classification in 2015 compared to 2013 (from cool to coolwarm).
• The one observed decrease in thermal classification was at SXM-144, which moved from
cool-warm to cool.
We analyzed the temperature data using
a science-based protocol to classify sites based
on their thermal stability. We used selected
data points which met the protocol criteria to
create a temperature nomogram for each site
using both water and ambient air temperatures.
Conditions for the protocol are met when air
temperature exceeds 24.5 °C between July
1 and the first week in September. Water
temperature readings are recorded at 4:30 p.m.,
the typical maximum daily water temperature for Ontario streams. Once the thermal
stability of a stream is known, it can be classified under one of five thermal categories:
cold, cold-cool, cool, cool-warm, and warm. This example nomogram shows how
maximum air and water temperatures at specific points in time were used to classify
the reach of Sixteen Mile Creek below the Kelso Reservoir as a cool water system.
SXM-144
Warm
SXM-314
Cool-warm
SXM-40
Cool
SXM-347
SXM-349
40
7
SXM-152
SXM-113
Cool-cold
e
SXM-437
e
Cold
SXM-435
SXM-433
Dry
SXM-533
SXM-131
SXM-532
SXM-30
e
40
3
SXM-105
SXM-20
GRN-65
SXM-205
SXM-103
GRN-66
GRN-22
©
SXM-151
Warm
!
(
Cool
!
(
Dry
Conservation Halton
Watershed Areas
!
(
Cool-Warm
!
(
Cool-Cold
!
(
N/A
Municipal Boundary
0
1
2
4
6
8
e
40
3
GRN-18
GRN-184
10
Kilometres
The highest temperature in 2015 was observed on July 29 at
station SXM-108, located downstream of the QEW (air 31.9 °C,
water 30.9°C).
GRN-5
GRN-65
©
GRN-66
GRN-22
GRN-20
GRN-73
GRN-27
GRN-49
GRN-7
GRN-89
NM6
!
(
This mapping was produced by Conservation Halton and should be used for information purposes only. Data sources used in its
production are of varying quality and accuracy and all boundaries should be considered approximate. Conservation Halton
disclaims all responsibility for any and all mistakes or inaccuracies in the information and further disclaims all liability for loss or
damage, which may result from the use of this information. This mapping is provided as a public service and does not constitute
advice or endorsement by Conservation Halton of any specific product, service, organization or agency. This map is protected by
copyright (© 2014) and may not be reproduced without written consent from Conservation Halton. Any copying, redistribution or
republication the content thereof, for commercial gain is strictly prohibited.
Produced by Conservation Halton GISP under license with Ontario Ministry of Natural Resources, Copyright © Queens Printer 2016.
MN6
Watercourse
©
407
Cold
©
GRN-7
GRN-60
e
!
(
GRN-186
SXM-108
QE
W
MN6
Sixteen Mile Creek
Temperature Station 2015
GRN-20
SXM-107
e
Water temperature monitoring was undertaken
at 26 sites within the Sixteen Mile Creek
watershed and another 12 sites within the
Grindstone Creek watershed in 2015. Data were
collected using submersible dataloggers which
are installed in late spring and record water
temperature every 30 minutes until early fall.
• Twelve dataloggers were deployed across the Grindstone Creek watershed with nine
of them yielding temperature data suitable for nomogram analysis. The remaining
three sites were not analysed because dataloggers could not be retrieved or were
exposed to the air as water levels receded in the summer. Three stations were
classified as cool and six as cool-warm (see figure below). These temperature patterns
reflect a watershed that has abundant groundwater resources, but also widespread
agricultural and urban development.
40
7
What did we do in 2015?
SIXTEEN MILE CREEK
e
All animals breathe and need oxygen to survive, even those living
in water. Since cold water can hold more oxygen in saturation than
warm water, temperature can be an important factor in determining
the composition of aquatic communities. Coldwater sensitive species
(e.g. Trout, Sculpins, some Mayflies and Stoneflies) can’t breathe very
efficiently and therefore need cold, clean water to survive. Warmwater
species (e.g. Carp, Sunfish, Bass) breathe very efficiently and are
more tolerant to warm water where impurities can rob the water of
dissolved oxygen. Tracking thermal trends in creeks in the summer is
one way to determine the health and status of aquatic communities.
GRINDSTONE CREEK
40
1
Why do we monitor water temperature?
What we found:
Grindstone Creek
Temperature Station 2015
GRN-16
!
(
Cold
Watercourse
!
(
Warm
!
(
Cool
!
(
Dry
Conservation Halton
Watershed Areas
GRN-22
!
(
Cool-Warm
!
(
Cool-Cold
!
(
N/A
Municipal Boundary
GRN-60
0
0.5
GRN-28
1
2
3
4
Kilometres
This mapping was produced by Conservation Halton and should be used for information purposes only. Data sources used in its production are of varying quality and
accuracy and all boundaries should be considered approximate. Conservation Halton disclaims all responsibility for any and all mistakes or inaccuracies in the information
and further disclaims all liability for loss or damage, which may result from the use of this information. This mapping is provided as a public service and does not constitute
advice or endorsement by Conservation Halton of any specific product, service, organization or agency. This map is protected by copyright (© 2014) and may not be