Chapter 7 Table of Contents -...

Approved Quinte Region Assessment Report Chapter 7

September 2019 i Version 6.0

Chapter 7 Table of Contents

7 CLIMATE CHANGE ...................................................................................................................... 7-1

7.1 RESEARCH TO DATE FOR SOUTH-EASTERN ONTARIO .................................................................... 7-1 7.2 QUINTE MODELLING FOR CLIMATE CHANGE ................................................................................. 7-3 7.3 POTENTIAL IMPACTS ON WATER QUANTITY .................................................................................. 7-8 7.4 POTENTIAL IMPACTS ON WATER QUALITY .................................................................................... 7-9 7.5 POTENTIAL IMPACTS TO VULNERABLE AREA DELINEATIONS ...................................................... 7-10 7.6 MITIGATION/ADAPTATION TO CLIMATE CHANGE ........................................................................ 7-10 7.7 CONSIDERATIONS FOR MONITORING CLIMATE CHANGE .............................................................. 7-11 7.8 FUTURE WORK FOR UNDERSTANDING CLIMATE CHANGE EFFECTS IN QUINTE ........................... 7-11


September 2019 ii Version 6.0

Chapter 7 Table of Tables Table 7-1: CCCma Climate Change Estimate Factors .................................................................................. 7-5 Table 7-2: Precipitation .............................................................................................................................. 7-7 Table 7-3: Snowfall ..................................................................................................................................... 7-7 Table 7-4: Evapotranspiration .................................................................................................................... 7-7 Table 7-5: Total Runoff ............................................................................................................................... 7-7 Table 7-6: Baseflow .................................................................................................................................... 7-7 Table 7-7: Projected Lowest Monthly Baseflow in Moira River at Foxboro ................................................ 7-8

Chapter 7 Table of Figures Figure 7-1: Moira River at Deloro Flows (m

3/s) .......................................................................................... 7-6

Figure 7-2: Skootamatta River at Hwy 7 Flows (m3/s) ................................................................................ 7-6

Figure 7-3: Black River at Hwy 7 Flows (m3/s) ............................................................................................ 7-6

Figure 7-4: Moira River at Foxboro Flows (m3/s) ........................................................................................ 7-6


September 2019 7-1 Version 6.0

7 Climate Change

As part of the Assessment Report, there is an acknowledgement that

considerations of climate change are important. Some of the eastern Ontario

Source Protection Regions/Areas have prepared climate change reports for their

specific jurisdictions, Cataraqui (Watt 2009), Mississippi-Rideau (Oblak 2009)

and Trent Conservation (TCC 2009). The reports summarize a number of other

climate change reports and studies and describe some potential water quantity

and water quality impacts as well as some mitigation and adaptation

considerations.

This chapter of the Assessment Report provides a further summary of that work.

It must be noted that there is large uncertainty associated with climate change

across the globe. It is very clear that our climate is changing, but which aspects

of our climate, and how much they may change in the future, is very unclear. All

the potential impacts presented here are by no means definitive.

7.1 Research to Date for South-eastern Ontario

Climate change impacts are probably best understood by looking at the regional

scale (eastern Ontario) rather than by property, city or town. Much of the

research and the published reports done to date are structured this way. These

look at areas as large as eastern Ontario, or eastern Canada and the

northeastern United States. In fact, there is minimal research specific to

southeastern Ontario with regards to climate change. However, most of the

studies do come to the same general conclusions about potential climate change

in our area.

The Intergovernmental Panel on Climate Change (IPCC) (2007a, 2007b) reports

summarize potential climate change across the globe, looking at both global

variability as well as smaller areas such as eastern North America. The reports

synthesize results from 21 global climate change models. For our area, the

reports predict:

increase in temperature, higher winter minimum temperatures; and

summer maximum temperatures;

more winter precipitation;

changes in summer precipitation are less certain;

small increase in runoff (may not be statistically significant); and

more frequent heavy precipitation.



It has also been observed, since the IPCC report was published, that the

predictions it contains are actually occurring faster than expected (Richardson et

al. 2009).

Also in 2007, the Ontario Ministry of Natural Resources produced a report

(Colombo et al 2007) and mapping considering climate change in Ontario. The

authors used Canadian data provided by Natural Resources Canada.

Specifically, this study looked at the relative change in temperature and

precipitation for three 30 year periods (2011-2040, 2041-2070, 2071-2100),

compared to the 1971-2000 period. It must be noted that the 1971-2000 period

happens to be one of the wettest periods in recent history (Hogg 2007) based on

the analyses of climate data conducted by Mekis and Hogg (1999). The MNR

study predicts:

precipitation decreases from zero to ten per cent in most areas of the

region, though some areas show an increase of zero to ten percent (this

does not represent a statistically significant change), and

temperature increase of a few degrees, more in the winter months than

summer months.

In addition to the IPCC and MNR studies, numerous other studies and reports

have been completed that provide much the same predictions and conclusions.

Some of these other reports include predictions such as:

decrease in the number of cold events;

increase in the number of warm events;

increase in night-time temperatures;

decrease in snow depth in many areas, but an increase in eastern

Ontario;

increase in the number of days of precipitation, specifically rain,

decrease in length of dry spells;

less ice cover on the Great Lakes (thinner, and shorter ice-in season); and

drop in Great Lake levels (predicted one metre for Lake Ontario if not

mitigated by change in dam operation at Cornwall ).

Some of the predictions presented are contradictory, which contributes to the

large degree of uncertainties associated with climate change models. This must

be taken into account when considering potential climate change; there is not

enough information to predict the results with certainty.



7.2 Quinte Modelling for Climate Change

Quinte Conservation undertook a review of potential effects of climate change on

the region with Dr. Harold Schroeter from Schroeter and Associates and the

assistance of a Quinte Region GAWSER model. The model was prepared to

simulate average conditions, 2-year and 10-year drought conditions for each of

three scenarios: The average conditions are defined by the meteorological

period 1950 to 2005. The 2-year and 10-year-droughts are defined in the

Technical Rules as:

2-Year Drought

The continuous two year period for which precipitation records exist with

the lowest mean annual precipitation.

10-Year Drought

The continuous ten year period for which precipitation records exist with

the lowest mean annual precipitation.

Three modelled scenarios include:

1. Current meteorological conditions

2. Conditions in 2050

3. Conditions in 2090

This work made use of a Canadian Centre for Climate modelling and analysis

(CCCma) gridded model output for southern Ontario (Environment Canada

2009). The model provided gridded modifiers for meteorological inputs such as

temperature, precipitation, cloud cover, solar radiation and wind speed.

The Quinte region fell within vertical grid points 76 and 77 and horizontal grid

points 36 and 37. Specific modifiers for the Quinte Region were developed by

averaging each of the horizontal and vertical factors (note that the temperature

change factors are provided in degrees C). The resulting modifiers are

assembled in Table 7-1. This table shows that precipitation will increase in the

winter and spring months and decrease slightly during summer and fall.

Temperature will likewise increase in winter and spring and less so in the

summer and fall. The Quinte Region GAWSER model used the precipitation and

temperature multipliers to develop the models to determine the potential effects

on the Quinte Region.

The following table contains a summary of the modifiers used in the Quinte

Region GAWSER (Guelph All Weather Sequential Event Runoff) model. The



model was capable of simulating evapotranspiration using the Linacre method

that is discussed in detail in Chapter 3. It is also capable of redistributing

snowfall, providing estimates of snow melt, and separating runoff from infiltration

through nine soil types and two soil layers. The Quinte model was constructed

for the water budget exercise and its development is further discussed in Chapter

3.

The initial modelling work was centred upon development of a model to simulate

current meteorological conditions. This was assisted by placing nodes at stream

gauge locations so that the predicted model output can be verified by actual

stream flow measurements. The model was verified using meteorological data

from 1950 to 2005. Once the model verification or calibration was completed two

future scenarios were programmed into the model by making use of the climate

change factors in Table 7-1.

Model results were provided as an ASCII (American Standard Code for

Information Interchange) file and these were imported into Excel spreadsheets

for comparison. The results generally show peak stream flows are experienced

earlier in the spring and summer flows are drier. Figures 7-1 to 7-4 show flows

from three scenarios discussed above for several Moira flow gauge stations. The

current conditions show a large peak runoff in April. This peak is reduced in

2050 and 2090 and is also earlier. Also, the summer low flow conditions appear

to become more reduced.



Table 7-1: CCCma Climate Change Estimate Factors

CCCMA Climate Change Estimates for Quinte Conservation Source Protection Region

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Mean

Cloud Fraction

C2030 1.04 1.04 0.99 1.03 1.02 1.03 0.97 0.94 0.97 0.99 0.99 0.98 1.00

C2050 1.05 1.07 1.06 1.04 1.02 0.99 0.96 0.95 0.96 1.00 1.01 0.99 1.01

C2090 1.06 1.13 1.09 1.08 1.02 1.05 1.04 0.95 0.98 0.99 0.99 0.96 1.03

Evaporation

E2030 1.25 1.41 1.15 1.21 1.11 1.01 1.02 1.04 1.04 1.05 0.96 0.81 1.09

E2050 1.20 1.70 1.17 1.39 1.13 1.03 1.03 1.06 1.06 1.07 0.95 0.74 1.13

E2090 1.02 1.79 1.52 1.86 1.19 1.04 1.03 1.07 1.08 1.10 0.96 0.63 1.19

Precipitation

P2030 1.05 0.99 1.01 1.06 1.01 1.11 1.02 0.92 1.02 1.01 0.97 0.99 1.01

P2050 1.04 1.07 1.07 1.15 1.03 1.02 0.94 0.88 0.97 0.98 0.97 0.95 1.01

P2090 1.06 1.21 1.28 1.19 1.07 1.11 0.99 0.90 1.03 1.13 0.98 0.99 1.08

Incident Solar Radiation

S2030 0.96 0.97 0.98 0.97 1.00 0.98 0.99 1.02 1.00 1.00 1.00 1.01 0.99

S2050 0.97 0.94 0.96 0.97 0.99 0.98 1.00 1.01 1.00 0.99 0.99 1.00 0.98

S2090 0.96 0.92 0.93 0.96 0.97 0.94 0.93 0.97 0.97 0.97 0.98 1.00 0.96

Mean Screen Temperature

T2030 3.97 4.36 2.55 2.07 1.71 1.47 1.56 1.49 1.73 1.29 1.18 0.85 2.02

T2050 4.87 6.29 3.83 3.33 2.69 2.22 2.19 2.14 2.16 2.10 1.96 1.05 2.90

T2090 6.11 8.97 6.68 7.40 5.91 5.07 4.28 4.13 4.20 4.34 4.07 2.49 5.31

10-m wind

W2030 1.04 1.06 0.99 1.06 1.02 0.97 0.98 0.98 0.98 0.99 0.94 0.92 0.99

W2050 1.00 1.06 1.00 1.07 1.01 0.94 0.93 0.95 0.96 0.96 0.93 0.86 0.97

W2090 0.93 1.07 1.01 1.13 0.95 0.90 0.90 0.92 0.90 0.94 0.90 0.80 0.95



Figure 7-1: Moira River at Deloro Flows

(m3/s)

Figure 7-2: Skootamatta River at Hwy 7

Flows (m3/s)

Figure 7-3: Black River at Hwy 7 Flows

(m3/s)

Figure 7-4: Moira River at Foxboro Flows

(m3/s)

Water balance values were provided by the model output showing the potential

changes to precipitation, snowfall, evapotranspiration, total runoff and baseflow.

These values are provided in Tables 7–2 to 7–6 respectively. These are annual

totals and will not reveal the seasonal variations discussed above. The model

output provided monthly water balances for each station and scenario, but these

are too cumbersome to reproduce here. The Figures 7–1 to 7–4 are included to

illustrate the monthly trends for total flow.

The effect of increased precipitation and temperature on water quantity of the

Moira River system is interpreted by reviewing the Average Conditions columns

in Tables –2 to 7–6. The portion of precipitation that is expected to fall as snow

is not expected to increase (Table 7-3).

Evapotranspiration, on the other hand, is expected to increase significantly in

both 2050 and more so by 2090 by well over 100 mm (Table 7-4). Total runoff in

Table 7-5 is projected to remain relatively unchanged in the 2050 and 2090

scenarios.

Moira River at Deloro

0

2

4

6

8

10

12

14

16

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

Flo

w (

cm

s)

Average

50 Years

90 Years

Skootamatta River at Hwy 7

0

5

10

15

20

25

30

35


Flo

w (

cm

s)

Average

50 Years

90 Years

Black River at Hwy 7

0

5

10

15

20

25


Flo

w (

cm

s)

Average

50 Years

90 Years

Moira River at Foxboro

0

20

40

60

80

100

120


Flo

w (

cm

s)

Average

50 Years

90 Years



Table 7-2: Precipitation

Average Conditions 2 Yr Drought 10 Yr Drought

Station Current 2050 2090 1963-1964 2050 2090 1957-1966 2050 2090

Deloro 931 943 1014 718 729 777 804 817 948

Black 950 970 1047 876 892 959 895 922 1130

Skootamatta 987 1008 1089 905 922 994 927 955 1173

Foxboro 944 958 1033 812 824 887 859 875 1057 Note: All units are in mm depth

Table 7-3: Snowfall


Station Current 2050 2090 1963-1964 2050 2090 1957-1966 2050 2090

Deloro 208 220 208 156 155 142 183 182 205

Black 200 199 205 238 240 240 221 233 248

Skootamatta 194 194 200 231 234 234 215 226 241


Table 7-4: Evapotranspiration


Station Current 2050 2090 1963-1964 2050 2090 1957-1966 2050 2090

Deloro 557 613 682 557 586 646 542 578 672

Black 556 599 663 547 572 628 543 570 663

Skootamatta 555 605 672 551 577 637 545 577 668


Table 7-5: Total Runoff


Station Current 2050 2090 1963-1964 2050 2090 1957-1966 2050 2090

Deloro 371 331 332 218 188 182 258 235 327

Black 389 369 382 362 350 360 349 349 497

Skootamatta 430 404 418 394 375 387 382 376 545

Foxboro 400 366 376 328 305 311 331 316 453

Note: All units are in mm depth

Table 7-6: Baseflow


Station Current 2050 2090 1963-1964 2050 2090 1957-1966 2050 2090

Deloro 180 179 178 130 124 117 138 136 185

Black 189 187 189 177 177 175 147 153 252

Skootamatta 216 209 210 196 193 208 170 177 277


What happens to seasonal low flow values in these scenarios is summarized in

Table 7-7 following based on the example of the Moira River at Foxboro station.

It can be seen from this table that lowest monthly base flows in the river are

projected to diminish over time although it is apparent from Table 7-6 above that



annual base flows will remain fairly steady. Again, the effects of climate change

are expected to be more pronounced seasonally.

Table 7-7: Projected Lowest Monthly Baseflow in Moira River at Foxboro

Average 2 yr Drought 10 yr Drought

Period Flow

(m3/s)

Lowest

Month

Flow

(m3/s)

Lowest

Month

Flow

(m3/s)

Lowest

Month

Current 4.1 Sept 2.3 Sept 2.2 Sept

2050 2.7 Sept 1.7 Sept 1.6 Sept

2090 2.5 Aug/Sept 1.5 Sept/Oct 2.2 Sept

Drought scenarios provide less reliable predictions since they are based on short

periods of record. The application of the precipitation modifier on the drought

scenario may not be scientifically appropriate. It implies that precipitation totals

would increase during a drought period. Naturally, if precipitation increases at

the same rate as Average conditions the evapotranspiration and total runoff

would increase over time. Perhaps more telling is the projected seasonal low

base flow value for the 2-year drought. The historical 2-year drought had a base

flow of 2.3 metres per secondduring September. This value decreases in the

model results to 1.5 metres per second by 2090 and is projected to occur during

both September and October (Table 7-7).

7.3 Potential Impacts on Water Quantity

The climate projections vary and impacts are dependent upon those projections.

The Quinte Region impact modelling was based on the Canadian Centre for

Climate Modelling and Analysis climate model that projects increased

precipitation. Evapotranspiration increases significantly and annual runoff

remains generally the same. Annual base flows also remain generally

unchanged, but seasonally summer base flows are anticipated to diminish.

Some models suggest a decrease in precipitation could occur. In either event,

storage of runoff will become more important to provide water supply during low

base flow periods.

If climate change produces a decrease in precipitation and an increase in

temperature, then we can expect that evapotranspiration will also increase if

sufficient soil moisture exists.

The projected temperature increase and earlier spring runoff despite the

disagreement in precipitation projections would have common impacts on water

quantity listed below:



less water available for surface storage (lakes and wetlands), flow

augmentation, etc., and consequently less supply for drinking water;

further, the demand is expected to increase, given the longer warm and

dry periods;

lower lake levels in summer, wetlands dry up, recreational problems

(boating, swimming, etc.);

less water recharging into the ground, lower groundwater levels, dry wells,

dry groundwater fed streams/lakes; and

more rain vs. snow, earlier freshet, less water to ground during snow melt,

but more during traditional winter periods.

7.4 Potential Impacts on Water Quality

The impacts to water quality due to climate change will also vary depending on

what actually changes.

If higher temperatures occur, expectations would include:

warmer winters, possibly allowing the overwintering of pests/invasive

species;

warmer winters/waters may also allow new pests to emigrate, causing

fouling of intakes similar to current zebra mussel problems;

warmer winter temperatures could mean less snow and ice accumulation

leading to reduction in sand and salt application. However, more freezing

rain may develop, meaning more salt and sand needed;

less snow may mean less “toxic flush” into surface water as snow melts;

reduced stream flows, means an increase in contaminant concentration

potentially leading to effects not normally experienced; and

warmer surface water, which will foster more (and earlier) algal growth

leading to more frequent fouling of intakes and require increased

treatment at the drinking water plants.

If higher precipitation occurs, or more intense precipitation, more contaminants

may be washed off the surface and into the water. There was a link found

between heavy precipitation and water borne disease outbreaks (CCSP, 2008).

More erosion would be expected due to heavy precipitation, which could also

increase the loading of contaminants bound to sediment into streams and

groundwater.

During the period when the former Village of Napanee took its municipal water

from the Napanee River, low flows were noted to negatively impact water quality.

To reduce the impacts of low summer flows on water quality, two large dams and



reservoirs were constructed at the Depot Lakes to provide low flow

augmentation. The Second Depot Lake Dam was constructed in 1958. Third

Depot Lake Dam was completed in 1975.

Further evidence of impact on low flows to river quality is again with reference to

the Napanee River. Quinte Conservation staff regularly installs seasonal weirs on

several rivers for summer recreation. The Newburgh Weir on the Napanee River

is no longer installed due to very poor water quality conditions that would

routinely develop over the summer.

7.5 Potential Impacts to Vulnerable Area Delineations

Climate change may also mean changes to the various vulnerable area

delineations.

Wellhead Protection Areas

reduced recharge may mean larger capture zones (WHPAs) in supply

wells in order to meet demand;

reduced recharge may also lead to lower groundwater levels and reduced

discharge to surface water (i.e. reduced base flow); and

earlier runoff timing will also affect the timing and duration of groundwater

recharge affecting supply.

Intake Protection Zones

higher temperature may mean lower water levels due to increased

evapotranspiration, which could expose some intakes to the surface, or

surface impacts; and

warmer temperatures resulting in a shorter ice cover period may make

additional land use activities subject to consideration (e.g. shipping), and

given that winds are generally stronger in the winter, this would require an

increase in the size of wind-derived IPZs.

Significant Groundwater Recharge Areas

SGRAs are based on the composition of the soil and rock, so the

identification of the areas will probably not change.

7.6 Mitigation/Adaptation to Climate Change

Awareness of Climate Change is important in order that efforts can be made to

mitigate the effects and prepare to adapt. Some of the mitigation/adaptation

measures for consideration should include:



adopting water conservation measures to ensure that reduction in storage

can be accommodated in reduced use;

promoting water conservation and reuse methods such as rainwater

harvesting, grey water systems, etc.;

monitoring of groundwater levels, groundwater recharge and discharge,

groundwater movement, stream flow (particularly low flows), precipitation,

evaporation, and radiation, to name a few. This monitoring data will help

to identify what parameters are changing, and how they are changing.

Modelling results are much more useful by actual data for calibration and

validation (Silberstein 2006). As he states, “we cannot manage what we

do not measure”;

continuing analysis of existing data, by multiple independent experts to

improve our confidence in detecting past changes ( as recommended by

the Climate Change Science Program (CCSP) 2008);

developing new storage opportunities or increasing existing storage

capacities; and

providing municipal water to those areas that experience water shortages

in private well supplies if possible.

7.7 Considerations for Monitoring Climate Change

Climate change is a global phenomenon with local variation. This indicates that

monitoring the changing climate should be coordinated by higher levels of

government. Results of climate change are however, locally measurable and this

would capture local variations in climate change impacts.

Most studies agree that the current monitoring of climate is not well suited to

capturing the right data to identify what parameters might change, and how they

might change. More monitoring is needed, as identified by a number of sources.

Specific recommendations on monitoring are not necessarily appropriate for this

document. Monitoring should be done through a partnership among all levels of

government (federal, provincial, municipal), as well as scientific/research

organizations such as conservation authorities and universities. Some of the

parameters that should be monitored include: precipitation (rain, snow, rate),

evapotranspiration, radiation, water and air temperature, and water use, to name

but a few.

7.8 Future Work for Understanding Climate Change Effects in Quinte

This is a rapidly developing field of study that has only recently received any local

study. Climate change understanding is developing in Canada and regional

models provide some insight on the effects on Quinte. Global climate models are

being refined and suggest the projections used in the current study may be high.



As such, the current climate change work should be reviewed with updated

modelling as it becomes available to provide improved projections on potential

impacts.

In the Quinte region modelling completed for the climate change effects, several

subwatersheds lack groundwater or surface water monitoring that would add

confidence as calibration events. Future work should incorporate new monitoring

information in the Quinte model to improve interpretation of the local effects.

Within the model are capabilities that were not engaged that could better

evaluate the changes in evapotranspiration. Potential evapotranspiration

routines require improved local data to support climate change effects using

projected changes in cloud cover, solar radiation and wind speed.

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