Tier II and Tier III Water Budgets

Module 10 – Water Budgets for the Region – Tier 1; Tier 2; Tier 3

“The purpose of the watershed-level water budget is to determine the volume of surface and groundwater available for the benefit of both human populations and natural systems.”

– Water Budget Analysis on a Watershed Basis, Queen’s Printer for Ontario, 2000

Learning Expectations

• By the end of this session you will be able to:
• Understand some potential effects of climate on water budgets
• Recognize the impact of land management on local water budgets
• Recognize the impact of water management on local water budgets
• Understand the effects land cover type, density and management practices have on infiltration, runoff, and groundwater and surface water flow

Chapter 3 of the Maitland Valley and Ausable Bayfield Assessment Reports is called Water Budget.

Chapter 2.3 of the Maitland Valley and Ausable Bayfield Assessment Reports is called Water Quality and Quantity.

Chapter 5 of the Maitland Valley and Ausable Bayfield Assessment Reports is called Potential Impacts from Climate Change.

Section One – Module Content – Learning Expectations and Activities

Unit 1 – Will our water supply be enough tomorrow?
Climate Change, Climate Variability and other Factors
How is water used?
Municipalities and institutional use (e.g., schools and hospitals)
Industrial and recreational uses
For food production and agriculture
Domestic Consumption

Unit 2 – The Groundwater System – Geology and Hydrogeology 101
Geology and the Groundwater System
Paleozoic Bedrock
Pleistocene Glacial Geology
Hydrogeology and the Groundwater System
Bedrock Aquifers
Bedrock-Overburden Aquifer Interaction
Overburden Aquifers
Groundwater/Surface Interactions

Unit 3 – The Surface Water System

Factors Affecting Surface Water Quantities
Climate
Land cover
Soil
Infiltration
Runoff and stream flow
Baseflow

Unit 4 – Wrapping It Up

Summarizing and thinking about implications

Field Learning Assignment

Self-Assessment on Learning Goals

More Help

Logging and Linking: Next Steps, Continuing questions and unresolved issues.

Activity 1 – Group Dialogue – Review of Field Learning Assignment

Title: What is future for our drinking water supplies?

What insight does the documentary An Inconvenient Truth give us about potential effects on water supplies in the future?

Activity 2 – Group Dialogue – Title: Review of Learning Goal Self-Assessment

Unit 1 – Will our water supply be enough tomorrow?

Climate Change, Climate Variability and other Factors

Activity 3 – Group Activity – Stand on the Line – Title: What is our water supply future?

When asked by your facilitator, stand on the part of the line that best represents your view – from ‘Abundant Supplies’ to ‘No Significant Water Supplies’.

How much water is there for the future?

Globally?

Nationally?

Provincially?

Locally?

Activity 4 – Group Dialogue – Title: Promoting Water Efficiency

1. What happens if there isn’t enough water in the future?
2. Review a case study of how water efficiency and protection of water supplies takes place. For example, look at the case of Glen Pleasance of Durham Region, who has been using Community-Based Social Marketing (CBSM) to reduce residential water use “with impressive results.”

How does he promote water efficiency?

1. How could his approaches be applied to other water conservation programs?

Activity 5 – Small Group Activity – Share, Listen, Create – Title: Quotable on Quantity

In your small group individually develop a response to one of the following quotations.

Then, share with your small group, listen to your peers.

Develop, time permitting, a group position or response at your table to this quotation.

1. “One of the key factors explaining the high residential consumption rates is the lack of financial incentive to Canadian households to use less water. For instance, in 1999, unmetered households which pay a flat rate for water, used 50 per cent more water than metered households, which pay for water by volume used.”
   – Philip Dearden and Bruce Mitchell, Environmental Challenge and Change: A Canadian Perspective. Second Edition, 2005. Page 437.
2. Quotation by Marq de Villiers:
   “If you’re short of water, especially clean water, the choices are conservation, technological invention, or the politics of violence.”

Can conservation save our water?

Will conservation take place?

Can technological innovation or inventions save the day?

No?

Will inaction on these two fronts really doom us to a world short of drinking water?

Is de Villiers correct?

Prognosticator, I. A. Shikolomanov (Director of the Leningrad Hydrometeorological Institute and winner of the 2001 International Hydrology Prize) tells us that by 2025, the supplies of fresh water to a third of the world will be catastrophically inadequate. [Philip Dearden and Bruce Mitchell, Environmental Challenge and Change: A Canadian Perspective. Second Edition, 2005. Page 424].

Consider further what I. A. Shikolomanov said:

“The state of the world water resources, deficit of clean fresh water in many regions of the world, water conflicts between different countries, forthcoming water crisis – those are our common problems, our concerns, and responsibilities. Those problems are important for both: our and future generations. They can be solved only if there is general understanding of how exclusive and unique fresh water is for (the) life and well-being of humanity, and how sensitive it is to unwise and harmful activities. This understanding should be based on fundamental knowledge in the field of hydrology and water resources. “

– Pr Igor A. Shikolomanov

1. Consider this quotation:

‘A Future of Scarcity’

Years of rapid population growth and increasing per capita consumption have squeezed the world’s freshwater resources. As global population has grown to nearly 6.1 billion today (and continues to grow by about 78 million people each year), the demand for fresh water in some areas exceeds nature’s capacity to provide it. A growing number of countries are expected to face water shortages in the near future—shortages that will be fueled by problems both on the demand side (notably rapid population growth) and on the supply side (mainly inadequate water supplies and poor policies).’

– from ‘The Coming Freshwater Crisis is Already Here,’ by Don Hinrichsen and Henrylito Tacio.

Activity 6 – Multimedia Presentation – Title: Climate Change and Variability and Tomorrow’s Water Supplies

Find out more about climate change from one or more of the following sources.

Possibilities might include:
DVD video interview with Joan Klaassen, of Environment and Climate Change Canada, produced by Ausable Bayfield Maitland Valley Source Protection Region
Multimedia presentation by Dwight Boyd, Senior Water Resources Engineer with Grand River Conservation Authority (presented March 2007 to Ausable Bayfield Conservation Authority)
Conservation Ontario presentation on public attitudes related to water and climate change

Climate change document prepared by Maitland Valley Conservation Authority detailing some of the possible impacts in Maitland Valley watershed (2007)
Climate change position paper approved by Ausable Bayfield Conservation Authority (2007)
Rob de Löe and Aaron Berg, Mainstreaming Climate Change in Drinking Water Source Protection Planning in Ontario, Pollution Probe and Canadian Water Resources Association, March 31, 2006.
Adapting to Climate Change, an Introduction for Canadian Municipalities, Canadian Climate Impacts and Adaptation Research Network, February 2006.
Planning for Extremes, A Report from a Soil and Water Conservation Society Workshop, Soil and Water Conservation Society, November 1-3, 2006.

Review the diagram of the hydrologic cycle and keep the diagram in front of you.

Discuss what implications projected climate change could have on water quantity.

1. What projected impacts will climate change have on temperatures?
2. What effects could climate change have on the processes outlined in your diagram of the hydrological cycle?
3. What effect could climate change have on weather events, according to scientists?
4. How might changes in land cover affect the processes in the hydrological cycle diagram?
5. How might changes in soil characteristics affect the processes described in the hydrological cycle?
6. What effects could climate change have on water quantity?
7. What effects could climate change have on water quality?
8. What land management effects could climate change have?
9. What water management effects could climate change have?
10. What implications does climate change have on the technical documents prepared by/for the Source Protection Committee (SPC)?

Activity 7 – Facilitated Group Dialogue – Title: How water is used here

List the various uses for water in our region. This is an activity where the knowledge brought by representatives of each sector will be really helpful.

1. Municipalities
2. A number of communities are targeting both demographic and economic growth.

How much will that elevate water supply demands?

1. Agriculture and food production
2. How are industries changing? How might those changes affect water quantity use?
3. Private Domestic Use
4. Industrial Uses
5. Commercial Uses
6. Recreational and Other Uses

Unit 2 – The Groundwater System – Geology and Hydrogeology 101

Geology and the Groundwater System

Paleozoic Bedrock

Pleistocene Glacial Geology

Hydrogeology and the Groundwater System

Bedrock Aquifers

Bedrock-Overburden Aquifer Interaction

Overburden Aquifers

Groundwater/Surface Interactions

Activity 8 – Presentation – Title: Groundwater Trivia

Geology and the Groundwater System

AquiZfer

Complete the following quiz as partners or in a small group and then take up as the large group.

1. What two major types of aquifers are there in the study area?

A.

B.

1. How many confined overburden aquifers are there in the source protection region?

---

Name
Type
Location
Description
Comments

1. How many surficial overburden aquifers are there in the source protection region?

Name
Type
Location
Description
Comments

1. Are the overburden aquifers in the source protection region all of the same kind?
2. Why are shallow overburden aquifers important?
3. What are the six periods of the Paleozoic era?
4. _________________________________________________
5. _________________________________________________
6. _________________________________________________
7. _________________________________________________
8. _________________________________________________
9. Through where is it believed that recharge occurs?

Unit 3 – The Surface Water System

Activity 9 – Multimedia Presentation – Title: Geology and Hydrogeology 101: Surface Water and Groundwater Systems and Land

1. Where does Lake Huron get its water from?

a) _________________________________________________

b) _________________________________________________

c) _________________________________________________

1. What are the six sub-systems of surface water systems?
2. What are six factors affecting quantity of surface water?
3. What are five roles of river systems?
4. How do groundwater and surface water interact?
5. Climate has an important role to play in a water budget.

Based on the presentation take note on the climate details in your source protection region:

a) Precipitation

b) Air temperature

c) Wind, Barometric Pressure, Solar Radiation

d) Evapotranspiration

e) Land Cover and Soil

f) Infiltration

g) Runoff and streamflow

h) Baseflow

Activity 10 – Personal Reflection – Title: Be a ‘Rock’ Star – Find out about our geology

Download presentation: Overview of Modules 9 and 10

1. Our region’s bedrock dates to the Paleozoic era.

TRUE

FALSE

1. Rocky Balboa is a local geological feature.

TRUE

FALSE

1. The Paleozoic era, which was marked by glaciation, ended 10,000 years ago.

TRUE

FALSE

1. Barney Rubble married Wilma.

TRUE

FALSE

1. The sedimentary rocks, in which our bedrock aquifers are located, were laid down in the period of Paleozoic-Pleistocene ‘Non-conformity’

TRUE

FALSE

1. Kid Rock is the name of a very young geological feature.

TRUE

FALSE

1. The period of Paleozoic-Pleistocene ‘Non-conformity’ was 300 million years long.

TRUE

FALSE

1. The Flintstones are famous because they came from the Ausable Bayfield Maitland Valley Source Protection Region.

TRUE

FALSE

1. The latest glacial advance/retreat, the Wisconsian Glaciation, is responsible for the deposition of the unconsolidated overburden of the study area.

TRUE

FALSE

1. Name two types or categories of aquifers:

a) __________________________________________________
b) __________________________________________________

Name your favourite ‘rock’ star: ___________________________

1. Bedrock Aquifers are mostly unconfined aquifers (exposed to permeable overburden and often exposed to the surface)

TRUE

FALSE

1. Bedrock aquifers are the usual source for private wells.

TRUE

FALSE

1. Bedrock aquifers are the source of municipal supply for the Village of
   Hensall.

TRUE

FALSE

1. Bedrock Aquifers was a spa resort that Fred and Wilma went to often.

TRUE

FALSE

1. Bedrock aquifers are the source of significant discharge for water bodies that are classed as ‘cold water fisheries.’

TRUE

FALSE

(overburden aquifers are the source)

1. Overburden aquifers are generally of two types: Surficial (unconfined) or Confined (e.g., overlain by impermeable clay and/or silt)

TRUE

FALSE

1. Overburden aquifers are often sources of baseflow for many surface water bodies

TRUE

FALSE

1. Overburden aquifers are aquifers that are reminders that you have too many burdens on you.

TRUE

FALSE

1. Overburden aquifers are in areas of hummocky terrain, infiltration increases and runoff is slowed.

TRUE

FALSE

Which answers did you get right? Which answers were not correct?

What questions do you have?

Unit 4 – Wrapping it Up

Summarizing and thinking about implications

Field Learning Assignment

Self-Assessment on Learning Goals

More Help

Logging and Linking: Next Steps, Continuing questions and unresolved issues.

Activity 11 – Group Dialogue – Title: Where do we stand on water quantity today and tomorrow?

1. Where do we stand today on water quantity?
2. Where will we stand tomorrow on water quantity?
3. Do we need to do water budgets for any of the region’s watersheds?
4. What changes, new conditions, or circumstances do you feel should be included in the new water budget?
5. If the Source Protection Committee was to decide no water budgets are needed at this time what is the value of IBID:

a) Understanding what a water budget is?

b) Understanding the water quantity challenges faced now and possible faced in the future?

Activity 12 – Title: Self-Assessment on Learning Goals – The Sources of My Understanding

Your friends are beginning to wonder about the hours you are spending on this course – they think, perhaps, that you have developed a secret life.

Re-assure them by telling them about three key insights you gained in this module:

1. ______________________________________________________

Your Evaluation of Group Performance

How do you rate this session?

How interesting was the material to you?

(Please circle the one that best describes your perspective).

Not interesting at all
Not very interesting
No opinion
Interesting
Very interesting

How involved did you feel?

Not at all involved
Not very involved
No opinion
Somewhat involved
Very involved

What parts of the session did you think were weak?

What parts of the session did you think were strong?

Group Performance Goals

How well did this group achieve its goals this session?

Group Goal Achievement

How well was this goal achieved?

(Please circle one)

Write goal here:

(Not at all)
(Only a little bit)
(No opinion)
(Somewhat well)
(Very well)

How could we do a better job of achieving this goal?

Write goal here:

(Not at all)
(Only a little bit)
(No opinion)
(Somewhat well)
(Very well)

How could we do a better job of achieving this goal?

Write goal here:

(Not at all)
(Only a little bit)
(No opinion)
(Somewhat well)
(Very well)

How could we do a better job of achieving this goal?

Write goal here:

(Not at all)
(Only a little bit)
(No opinion)
(Somewhat well)
(Very well)

How could we do a better job of achieving this goal?

Write goal here:

(Not at all)
(Only a little bit)
(No opinion)
(Somewhat well)
(Very well)

How could we do a better job of achieving this goal?

Write goal here:

(Not at all)
(Only a little bit)
(No opinion)
(Somewhat well)
(Very well)

Do you have any other feedback, input, concerns, question or comments about the working group performance or process?

Thank you for your important feedback.

A summary assessment will be completed and a report will be presented to the group at the beginning of next session.

More Help

Logging and Linking: Next Steps, Continuing questions and unresolved issues.

SECTION TWO – Priming the Pump

Notes, Definitions, Fact sheets

“If you’re short of water, especially clean water, the choices are conservation, technological invention, or the politics of violence.”

– Marq de Villiers, Water: The Fate of Our Most Precious Resource [2003, page 356].

Let’s Take a ‘Diversion’

Do you believe that Nortel will hit $150 a share? No? What if we asked you that question some years ago?

Just as the seemingly endless supply of rising technology stocks ended up being something of a mirage, the seemingly endless supply of water may be illusory.

Do we know when, or if, we will run out of oil?

Do we know when, or if, we will run out of water? Can we live without oil? Can we live without water?

Can we keep Canada’s water for ourselves while much of the rest of the world goes thirsty?

Is it ‘our’ water?

Will Canada even retain its large supply of water?

There are many questions to contemplate when it comes to water quantity around the world, in Canada, in Ontario and in our source protection region.

It’s not our job in a working group or committee to single-handedly solve the world’s water supply problems – however, it is our job is to participate in decisions on how to plan and manage our water resources for the benefit of the people living in our planning region now and in the future.

So, with these comments as an introduction, let us start session 10 with a ‘diversion.’ Let’s challenge ourselves to ask the question “Is there enough water to go around?” The opening activities of this module are a chance for you as a group and as individuals to reflect on the issues of protecting our supply of fresh drinking water.

We also, in this module, look at the water budget as a tool with implications for our understanding of water quantity and supply issues and modelling which can help us make decisions in the future and through this planning process.

Four Major Aspects of Water Budgeting

Let’s review the four major aspects of water budgeting:

1. The characterization of the surface water system (more specifically, examining the ‘sub-systems’ such as climate, infiltration etc.);
2. The groundwater system (the geology and hydrogeology and the characteristics of our aquifers);
3. The connections between the surface and groundwater systems, and;
4. Water use.

This module will look at:

1. The Groundwater System;
2. The Surface Water System, and;
3. The relationship between the Groundwater and Surface Water systems.

The Groundwater System

Do we have to understand geology to understand water quantity issues and water budgets?

Can’t we just study the behaviour of the aquifers in our region?

The ‘behaviour of aquifers’ is determined by the bedrock and overburden they occupy.

It follows then that it will be helpful to understand the area’s geology in an elementary way.

Geology of Ausable Bayfield Maitland Valley Source Protection Region

Consider this a ‘crash’ geology lesson or ‘Geology 101.’

Precambrian Basement Rocks

We get our geologic feet wet with brief mention of the Canadian Shield, the same rocks you may have rambled over on blueberry picking excursions in Algonquin Park.

No Precambrian Basement Rocks (Canadian Shield) are exposed in our source protection region and they have little direct influence on the hydrogeology.
However the shield was an influence in the deposition of later rocks, affecting for example the shape and character of the Lucas formation within which modern sinkholes formed.

Paleozoic Bedrock of Southern Ontario

Paleozoic sedimentary rock formations overlie the Precambrian and it is in these formations that the region’s bedrock aquifers are found.

Six Periods of the Paleozoic Era

Another Crash Geology Lesson:

The Paleozoic Era, which began about 542 million years ago and ended 251 million years ago, is broken down into six periods from oldest to youngest:
• Cambrian
• Ordivician
• Silurian
• Devonian
• Carboniferous
• Permian

The Ausable Bayfield Maitland Valley Source Protection Region’s bedrock aquifers are mainly within Silurian and Devonian formations.

Pleistocene Glacial Geology

Paleozoic-Pleistocene ‘Non-conformity’: Following the formation of the Paleozoic bedrock, 300 million years elapsed during which there were no new depositions
and during which the bedrock eroded and bedrock valleys formed. Weathering and fracturing created zones of high permeability – very important features in our hydrogeology. Features like the bedrock valleys (one of which runs from Atwood northwest toward Wingham) exert some control over the flow and distribution of groundwater.

Recent Geology

Wisconsian Glaciation

In some ways the above discussion is but a prelude to the significant landscape changes brought by glaciation. The 300 million hiatus in deposition came to an end quite recently as numerous glacial advances and retreats eroded the bedrock.
The latest glacial advance/retreat, the Wisconsian Glaciation, occurred ten to twenty thousand years ago. It is responsible for the deposition of the
unconsolidated overburden of the study area.

Holocene Erosion and Deposition

Erosion and deposition continue today and the watersheds’ rivers continue to erode and transport sediments.

The Hydrogeology of the Ausable Bayfield Maitland Valley Source Protection Region

The Behaviour of Groundwater

Do we have enough geology yet to talk about the behaviour of groundwater?

Yes, we are ready to discuss the hydrogeology of the region:

The behaviour of bedrock aquifers

The behaviour of overburden aquifers and

Groundwater – surface water interaction.

Two types of major aquifers – Bedrock and Overburden

Let’s start with a reminder – The region’s major aquifers are of two types, bedrock and overburden aquifers (surficial).

Bedrock aquifers are the more important groundwater source of drinking water.
The village of Hensall relied on groundwater from an overburden aquifer for its drinking water it switched to Lake Huron as its raw source of water for treatment and distribution as drinking water

All other municipalities which rely on groundwater sources tap into the bedrock aquifer for their supply. Most private wells also rely on the bedrock aquifers for their water supplies.

(Goderich and the municipalities of the Lake Huron Drinking Water Supply system use treated Lake Huron drinking water.)

Bedrock Aquifers

Within each specific bedrock formation, water quality and quantity can differ dramatically, largely due to the chemical and physical characteristics of the rocks themselves. Through most of the Source Protection Region, the bedrock aquifers are confined by an overlying (and protective) layer of clay and silt till. They are exposed at the surface in only a few locations. The piezometric surface (bedrock water table) is found well above the aquifer’s contact with the overlying glacial deposits. Investigate why it is confined – or ask the speaker – or put it on the ‘Parking Lot’ for questions to be answered in the future.

[View a map that shows the piezometric surface as well as groundwater flow directions.]

The map should also reveal that the piezometric surface dramatically drops off on a north-south trend just east of Exeter. This is explained as follows:

Permeability increases within the Lucas Formation, a characteristic likely associated with karst (sinkhole) features in the area.

The dramatic grade change may also reflect the existence of two bedrock aquifers at two different depths:

a) The deeper aquifer of the Lucas Formation, and;

b) The shallow, perched aquifer of the overlying Dundee Formation.

Regional (Bedrock) Groundwater Flow

Groundwater flow within the bedrock aquifers radiates from the Dundalk area (to the northeast of the region) and follows a west to southwest flow towards Lake Huron. [Note that a significant portion of the groundwater inside the study area originates from the north and east outside of the study area, an influx that will have to be quantified should a numerical, three dimensional groundwater flow model be developed.]

Bedrock-Overburden Aquifer Interaction and Groundwater-Surface Water Interactions

Recharge Areas

We conclude that because the bedrock aquifer is not exposed at the surface (for the most part) recharge occurs through the overburden. It is also believed that a significant amount of recharge occurs outside of the Source Protection Region.

Discharge

As with recharge, little is known about the discharge of water from the bedrock aquifer. Based on piezometric surfaces for the bedrock aquifer (as noted the bedrock water table is located within the overburden), it is felt the bedrock aquifer discharges into the overlying overburden aquifers. The extent of such an interaction is unknown. In the lower reaches of the major rivers (particularly the Maitland and Bayfield Rivers) bedrock is exposed and it is assumed that the bedrock aquifers discharge directly into the rivers in these areas. Ultimately the bedrock aquifers are thought to discharge directly into Lake Huron, offshore.

As noted in other sessions, there are several sinkholes in the east-central part of the region. These sinkholes provide a direct conduit of surface water to the bedrock aquifers for large surface drainage areas. In other words, a high volume of water is recharged into the bedrock aquifer via sinkholes.

Overburden Aquifers

There are many aquifers within the overburden (unconsolidated glacial deposits) that overlies the bedrock aquifers. These overburden aquifers:

Provide local drinking water (mainly private wells plus Hensall), and;

Contribute to surface waters, and;

Ultimately contribute to the recharging of bedrock aquifers.

Because most of these aquifers are unconfined, they are more susceptible than the bedrock aquifers to contamination from surface waters.

Information on these aquifers is sketchy – flow directions, water quality and quantity are poorly understood.

No mapping exists for those overburden aquifers, which are not exposed on the surface.

Are the overburden aquifers we know about the same kind?

Are they all equally susceptible to contamination?

No. In fact overburden aquifers are like a field of study onto themselves.

For example:

Some are confined or partially confined and potentially more protected.

Some have very high quality water though they are unconfined.

Most are sources for bedrock aquifers.

Many provide source water for surface water bodies.

If the known overburden aquifers are to be classified, we would distinguish:

1) Surficial, and;

2) Confined overburden aquifer.

Each type is summarized in table form below.

Surficial Overburden Aquifers

There are seven known Surficial Overburden Aquifers.

Name, Type & Location

Description

Comments

Lake Warren Shoreline Aquifer
unconfined aquifer,
narrow band parallel to Huron shore through entire region
former beaches and dunes, forming sand deposits.
likely recharged in situ
source for cold water lakeshore streams.
tapped by several private wells particularly in Goderich area

Lake Huron Beach Aquifer

aggregate aquifer (i.e., many unconfined aquifers)
beach deposits along shoreline of Lake Huron
likely recharged in situ plus surface runoff from lake bluffs.
aquifer flow likely towards Lake Huron.
used sporadically as source by cottagers

North Lambton Aquifer
Composite, unconfined aquifer located within former lakes,
(Nippissing-Algonquin), beach and more recent dune deposits.
recharged in situ
separated from the bedrock aquifer by 30 metres+ of clay till
one of the best understood overburden aquifers
extensively used prior to Lake Huron Water supply

Holmesville Outwash Aquifer
Located between the Wyoming and Wawanosh moraines
located in gravel and sand of unknown thickness.
host to aggregate operations
high quantity/quality aquifer.
likely recharged in situ with contribution from surrounding, higher
moraines.
tapped by several private wells and some small developments (e.g., Fernhurst Glen).
source for cold-water streams, & for Hay, Saratoga swamps.
ikely important baseflow source for Maitland, Bayfield & Ausable + Lakeshore streams

Wawanosh Kame Moraine Aquifer
moraine forming topographic high in Maitland & Nine Mile River Watersheds
hummocky terrain facilitates high infiltration and recharge
may be important source of bedrock aquifers recharge.
major source for coldwater Nine Mile River system & portions of the Maitland.
info on use, groundwater flow and quality lacking.

Howick Aquifer
centred on Howick Township. – composite aquifer
likely recharged in situ
situated in outwash deposit and glacial spillways which form area’s rolling topography.
includes Teeswater Drumlin Field and smaller eskers and spillways of Northern Huron and Perth.
source for North Maitland, Lakelet Lake & Creek and Blind Lake Bog.
likely recharge source for bedrock aquifer.
Mennonite/Amish use these shallow vulnerable aquifers.
little info on groundwater flow, water quantity/quality

Seaforth Moraine Aquifer
thin, linear band on the eastern flank of the Seaforth Moraine.
likely recharge in situ
some contribution from higher Seaforth moraine
little info on this aquifer,
thought to be important private well source in south part of region, where quality of bedrock aquifers has declined.
source for Ausable River and possibly bedrock aquifer

Confined Overburden Aquifers

There are two known Confined Overburden Aquifers.

[Consult map]

Name
Type
Location
Description
Comments

Hensall Aquifer
partially confined
centred on the village of Hensall
recharge located east of the aquifer in exposed sand deposits.
vulnerable to surface water contamination, corroborated by known water quality problems thought to be recharge source for bedrock aquifer.
was drinking water source for Hensall and area private wells.
Municipality of Bluewater opted to link Lake Huron system to village of
Hensall.
discharge from aquifer poorly understood.
little geological information.

Atwood/Dundas Bedrock Valley Aquifer
confined
situated within sand and gravel that has infilled the Dundas bedrock valley
(later covered with clay and silt rich tills.)
likely both recharges and discharges with the surrounding bedrock aquifers
aquifer considered transient for water flowing within the bedrock aquifer.

Groundwater/Surface Interactions

Shallow overburden aquifers are important sources of baseflow for many surface water streams, moderating flow and providing cold water, valuable for specific fisheries. The coarse-grained composition and topographic features of shallow overburden aquifers, particularly unconfined aquifers, combines to increase infiltration.

Cold Water Fisheries

Cold water fisheries indicate areas of significant discharge from shallow overburden aquifers. (See Map 1.4) Groundwater discharge is critical to baseflow and ecological health of the surface water system. Cold water fisheries tend also to have a higher water quality as overland runoff is diluted by groundwater discharge. [This illustrates clearly how water quantity and quality should be viewed together in a water budget.]

Hummocky Terrain

Hummocky terrain is described as follows:
An area of broad, gently sloping swales, and of very coarse-grained
materials,
Having greater depressional storage and
Increased flow lengths for overland flow.

Because of these factors infiltration is increased and runoff is slowed. In fact, overland flow is not likely to occur. Hummocky terrain then produces a disproportionately high volume of recharge to underlying aquifers.

Hummocky terrain has been identified in the Ausable Bayfield Maitland Valley Source Protection Region, but not yet mapped. Methodologies for filling this data gap are being tested.

Groundwater Monitoring

Groundwater monitoring locations were established in 2003 as part of the Provincial Groundwater Monitoring Network (PGMN). Water level and temperatures are recorded hourly. It is too early to identify trends. However, the monitoring will be enabling us to develop a three-dimensional groundwater flow model, focusing on seasonal variation in groundwater flow.

Water Use

So far we have studied the ins and outs of surface water systems and of groundwater systems. And we have learned about the interaction of groundwater and surface water. Is this leading somewhere?

The drinking water source protection program is aimed at protecting drinking water sources. So now, armed with an elementary grasp of the science we need to consider how we use water for human and economic purposes and how that water use may impact water quantities (and quality).

Data Sources

We use a number of water usage data sources to approximate the amount of water being extracted in the region:

The Provincial Permit To Take Water (PTTW) database,

The Water Well Information System,

Agricultural water usage studies and census data, and

Municipal Well Annual Reports.

Municipal Water Takings

Municipal supply systems account for a high proportion of water takings.

Considering groundwater first, most takings exploit bedrock aquifers.

Hensall, the exception, relied on an overburden aquifer.

The Lake Huron Primary Water Supply System, serving the City of London and numerous other communities, is a major taker. Noteworthy as a water budgeting consideration is the fact that most of the water taken outlets in the Thames River. As such, the draw from the Huron System is the region’s largest consumptive water taking.

Other water supply systems use Lake Huron, including Goderich and several smaller systems in North Lambton. Each one outlets into Lake Huron directly or via small lakeshore gullies.

Since 2001, municipal and large communal systems require flow meters and must report annual water consumption.

Agricultural Water Takings

Agriculture, including livestock feeding operations and irrigation, represents the region’s largest land use. As one would expect, water takings for this sector are significant. Agriculture relies heavily on bedrock aquifers. Surface water takings for agriculture are more numerous in the region’s south, as irrigation is considered an economical venture in that area.

Private Domestic Consumption

Private consumption within the region exploits the overburden and bedrock aquifers. Typically, this involves a drilled (less commonly a bored) well and water consumed is recycled into shallow overburden aquifers via septic systems. [To make ‘the water budget connection,’ an analyst calculates the water transfer from deeper aquifers (the well water drawn) to shallower aquifers (the outflow from septic systems) in order to represent the flow of groundwater in the water budget.]

Industrial and Recreational Uses

Several businesses rely on large quantities of water, including aggregate extraction, food processors, greenhouses, bait harvesters, and golf courses.
Most of these users tap into the bedrock aquifer; however, several take surface water.

Summary

Preparing a water budget involves four steps:

Four Steps in Preparing a Water Budget

1. Identifying the key components and processes of the hydrologic system.
2. Understanding the inter-connections of these components and processes, i.e., understanding water flows and pathways, and the fluxes of water between reservoirs.
3. Quantifying the fluxes.
4. Preparing the water budget.

For our purposes, we focused on steps 1 and 2.

Key Components and Processes

Ground Surface

Receives precipitation

Sends some away as runoff to surface water systems

Stores some in depressions or in the soil, depending on season and conditions.

Sends some to aquifers via infiltration.

Returns some of stored water to the atmosphere as evapotranspiration.

River Systems

Receives ground surface runoff

Receives groundwater discharge from overburden and bedrock aquifers.

Receives some of the water infiltrating the ground surface (called interflow).

Sends runoff to Lake Huron.

Via irrigation ‘returns’ some water to the ground surface.

Interflow

Some of the infiltrating water goes to surface water systems before it reaches the saturated zone.

Tile drainage accelerates interflow.

Infiltration

The movement of water from the ground surface through the unsaturated zone

To the saturated zone (the aquifers)

Overburden Aquifers

Receives infiltration (recharge).

Receives water from river systems via losing streams

Receives water from septic systems

May receive discharge from underlying bedrock aquifers.

Discharges to bedrock aquifers.

Discharges to private wells.

Discharges to surface river systems (high quality source to cold water streams).

Bedrock Aquifers

Inputs to bedrock aquifers include:

Recharge from ground surface where bedrock is exposed.

Recharge from overburden aquifers.

Recharge from river systems via losing streams.

Most notably, recharge via sinkholes, direct conduits for run-off.

Extrabasinal input.

Discharge and Outputs from bedrock aquifers includes:

Discharge into Lake Huron.

Discharge into some river systems.

Extraction for municipal and industrial purposes, most of which is treated in municipal wastewater treatment plants (WWTPs) and released into surface water systems.

Some however is diverted to overburden aquifers.

Surface Water Systems and Sub-Systems

Understanding the surface water systems requires understanding the surface water system’s ‘sub-systems’:

Climate

Land cover

Soil

Infiltration

Runoff and stream flow

Baseflow.

The Role of Climate

Climate is a key factor in the water budget.

Precipitation

Session 9 already revealed to us that precipitation represents a major input to the region’s water cycle.

In our area:

Annual precipitation ranges from 975 to 1185 mm across the region.

Precipitation is fairly uniform through the year, with the fall being somewhat wetter.

There is an indication annual precipitation has increased slightly over the past 50 years.

Air Temperature

Air temperature is another important factor, affecting for example evapotranspiration, ground conditions and therefore infiltration and runoff.

Average annual temperature ranges from 6.7 to 8 degrees Celsius.

Lake Huron has a moderating effect.

Average daily temperatures are typically below freezing from December to March.

A very slight rise in average temperature over the last 20 years is indicated.

Wind, Barometric Pressure and Solar Radiation

Once obtained, such data is useful in estimating evapotranspiration

Evapotranspiration
Long-term data is unavailable but it is estimated the region is experiencing evapotranspiration rates in the range of 500 to 575 mm/year.

Land Cover and Soil
As they are closely connected, these sub-systems are discussed under the same heading.
Land cover type and density affects infiltration and runoff and therefore groundwater and surface water flows.
Based on 1980 vintage data, it has been determined that 82 per cent of the region is agricultural while 15 per cent of the land is under undisturbed vegetative cover (such as woodlots and natural areas). Only three per cent of land is urban and industrial.

The percentage of agricultural land is somewhat higher in the south and in lakeshore gully areas.

Cultivated land leaves the land devoid of cover at times and in the growing season; row crops create an artificial cover pattern. The result may be faster infiltration and faster runoff. In recent years more farmers have begun to use conservation tillage practices resulting in improved soil cover. The exact extent of such land practices is not known.

The characteristics of landscape affect whether precipitation is intercepted (retained in the soil), infiltrates to aquifers or runs off into surface water systems.

Landscape characteristics also determine the number and type of pathways for contamination.
It is therefore important to understand the potential for infiltration as compared to the potential for runoff to occur, both over space and through time.
This understanding begins with an overview of two key characteristics, soils and land use.

[Review the soil information map.]

Note that:

Soils with low infiltration rates are more dominant in the southern parts of the region and in bands inland from the shore, suggestive of higher rates of runoff.

However, in dry conditions and where cracks form, the infiltration rate of such soil increases significantly.

[Consult the land cover map.]

Note that:

Much of the region is characterized by moderate vegetative cover.

Areas of low vegetative cover are generally more common in the ‘Gullies’ drainage areas along the Lake Huron coast.

[Consult the land use map.]

It examines tile drainage, a characteristic that can affect infiltration and runoff rates. In general, note that tile drains:

Encourage more rapid drainage in the spring and late autumn and when soils are saturated. This elevates stream flows.

Increase water storage capacity possibly delaying runoff peaks.

May enhance evapotranspiration rates.

Reduce compaction and help to maintain infiltration capacity.

Infiltration

Temporally, infiltration capacity varies depending on soil and cover at the time of the precipitation (as discussed). Observations indicate lower infiltration/higher runoff occur in the early spring and late fall periods.

Map describes the effect of the combined factors of soil and land cover.
(Lighter areas indicate relatively high infiltration capacity. Darker indicates higher surface runoff potential)

The analysis yields these observations:

Soils with lower infiltration rates (i.e., finer-textured soil) are more dominant in the southern half of the region and in bands along the lakeshore, suggestive that runoff rates will be comparatively higher/faster. [On the other hand finer textured soils have a tendency to develop short circuit pathways in the form of cracks or macropores. The effect can be a greater net infiltration capacity.]

While we can see that the south, central, north-western and north-eastern sections of the region are largely tile drained the effects on runoff and infiltration require further study.

Runoff and Streamflow

Stream flow maps best present the patterns and rates. Note that:

The southern part of the region has lower total annual runoff volumes.

On average, approximately 76 per cent of the total runoff occurs from December through May.

Water budgets can account for winter hydrology, snowmelt and early spring conditions.

Baseflow

Base flow maps best present the patterns and rates.

Note that:

Base flow values vary.

Many of the higher base flows are directly influenced by human-made factors such as Morrison Dam (and water releases) and Wastewater/Sewage Treatment Plants WWTPs (e.g., at Exeter, Listowel and Harriston).

Lake Huron, “the Final Destination” and a Key Source

Lake Huron receives water from all the components in the diagram.

Receives natural discharge from rivers, and aquifers.

Receives discharge from wastewater treatment plants (WWTPs).

Major source of drinking water.

But most of the water taken is used, treated and released outside the basin.

More Help
Do you want more information?
Do you want to learn more?

Your facilitator is prepared to discuss any topic or question with the goal of helping you move to the next module.

Alternatively, write down your thoughts and a facilitator will follow up with you.

Logging and Linking: Next Steps, Continuing questions and unresolved issues.

Please visit sourcewaterinfo.on.ca for current information.

Source: Environment and Climate Change Canada

Section Three

Other Resources – Handouts, Additional Readings,

Field Learning Assignment Findings

Reading, Listening and Viewing Resources:

View multimedia presentation on Building Resilient Watersheds to Prepare for Climate Change, by Dwight Boyd, Exeter, March 15, 2007

‘Mainstreaming Climate Change in Source Protection Planning,’ Ontario Ministry of the Environment (MOE) and Pollution Probe

View DVD interview with Joan Klaassen, Environment Canada, Ausable Bayfield Maitland Valley Drinking Water Source Protection Project, 2006.

Read ‘The Coming Freshwater Crisis is Already Here’

Water Budget Analysis on a Watershed Basis, Queen’s Printer for Ontario, 2000

Conservation Ontario brochure, What Landowners Can Do to Protect Water: Quality & Quantity

Field Learning Assignment

For next module, complete one of the following assignments:

a) Find out what a Water Response Team does

b) Have there been low water advisories issued in your watershed?

c) Identify:

a. Your major questions

b. Your major unresolved issues

c. Areas of concern and/or input

Report back to the group.

Information here is provisional, subject to change, and posted for local information and education purposes. For current information visit Ontario.ca and sourcewaterinfo.on.ca. We would like to acknowledge the support of the Government of Ontario. Such support does not indicate endorsement of the contents of this material.