presentation 3_may 9 2011

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Class # 3 – May 9, 2011Earth Sc 2WW3

Summer, 2011

Class Outline:

1. Groundwater - Continued

2. Group Work

3. Groundwater videos

4. Flooding

5. Hazel’s Legacy

Types of Soil Erosion

• Sheet

• due to the impact of rain and runoff from a

rainstorm

What is the significance of soil

erosion?


• Splash

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• Rill: small linear depressions in the soil surface


• Gully

• results in the formation of gullies

Consequences of soil erosion

Tree plantation

Evapotranspiration decreases

Ranching accelerates soil erosion by water and wind

Winds removefragile topsoil

Gullies andlandslides

Heavy rain leaches nutrients from soil and erodes topsoil

Rapid runoffcauses flooding

• e.g.: After deforestation of a hillside

Roadsdestabilizehillsides

Agriculture landis flooded andsilted up

Silt from erosion blocks rivers andreservoirs and causes flooding downstream

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What is Groundwater?

•Groundwater is water located beneath the ground surface.

•An underground geologic formation is called an aquifer.

•The water table often varies.

•Groundwater discharge.

•The study of groundwater is called Hydrogeology.

•An aquifer is a layer of porous substrate that contains and

transmits groundwater.

•The upper level of this saturated layer of an unconfined

aquifer is called the _______or _________. Below the water

table, where generally all pore spaces are saturated with

water is the ___________.

•Substrate with low porosity that permits limited

transmission of groundwater is known as an ________. An

__________ is a substrate with porosity that is so low it is

virtually impermeable to groundwater.

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Clay/Till Very low Very Low

•A _________is an aquifer that is overlain by a relatively impermeable layer (i.e.

__________ or ____________).

•If a confined aquifer follows a ____________from where it is recharged

(recharge zone) groundwater can become pressurized as it flows.

•This can create conditions where water can flow through the ground surface in

areas through the path of least resistance.

•The characteristics of aquifers vary with the geology and structure of the

substrate and topography in which they occur

<http://nationalatlas.gov/atlasftp.html?openChapters=chpwater#chpwater

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What is an aquitard/aquifer?

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The Great Artesian Basin in central and eastern Australia is one of the largest confined

aquifer systems in the world (almost 2 million km2).

Through analysis, hydrogeologists have determined that water within this aquifer can be

in excess of X years old.

http://www.derm.qld.gov.au/water/management/undergroundwater/index.html

Hot water bore hole

into the Great Artesian

Basin

http://www.answers.com/topic/great-artesian-

basin#ixzz1LQ76ZLzc

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Groundwater diagram, (c) Natural Resources Canada.

Wetlands contrast the arid landscape around Middle Spring, Fish

Springs National Wildlife Refuge, Utah.

Photo source: www.en.wikipedia.ca

What are the consequences of

overdrawing groundwater?

Falling Water Tables

• Nonrenewable vsRenewable

• Ogallala Aquifer

• Supplies 1/5 irrigated land in US

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Falling Water Tables

•Subsidence can occur when too much groundwater is extracted, leaving voids in the

formations below. Collapse may occur in this situation.

•The city of New Orleans is below sea level today – its subsidence is partly caused by

removal of groundwater from the various systems beneath it.

•The city of San Hose, California dropped 13 feet from land subsidence caused by

overpumping (from 1900-1950);


overdrawing groundwater?Land subsidence

Sinkhole in

Florida, 1981

San Joaquin

Valley

California, 1977

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overdrawing groundwater?

Salt water intrusions

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•Groundwater makes up about 0.61% of the entire

world's water, including oceans and permanent ice.

•Global groundwater storage is roughly equal to the

total amount of freshwater stored in the snow and ice

pack, including the north and south poles.

•Groundwater is an important source of water that can

be available during times of surface water drought.

•Groundwater is naturally replenished (or recharges)

by surface water that infiltrates into the ground, and

reaches the water table.

•Groundwater is critical to both terrestrial and aquatic ecosystems -

globally.

•The connection between groundwater and surface water is central to the

water cycle.

•Many water features (watercourses, wetlands, etc.) are at least in part

supplied by groundwater.

•Many aquatic species exist where they do, and are dependant upon, the

cooler temperatures and influence of groundwater.

•when groundwater is removed at a rate that exceeds recharge, and goes

beyond the point of equilibrium in the water cycle. As a consequence,

groundwater levels are lowered, which may reduce supply (potentially for

very extended periods), and may have significant impacts upon the

natural systems which also reply upon these resources.

The International Water Management Institute – 2007 study

On water sufficiency for global food production.

Identified that 1/5 of the world's population (1.2 billion+), live in

areas of physical water scarcity – i.e. There is not enough water

to meet their demands.

people live in areas experiencing economic water scarcity - lack

of investment in water or insufficient human capacity preclude

the ability of the areas to provide for the necessary amounts of

water.

The report concluded that the required amount of water to

match anticipated future food production requirements can be

attained on a global level, however, there would be local supply

constraints (uneven distribution) that may lead to a global water

crisis.

Is there enough water to meet global demand?

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Groundwater Videos

Group Work

FloodingEarth Sc 2WW3

Summer, 2011

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Flooding

• What is it?

• Is it a ‘natural occurrence’

• Is it a problem? If so why?

Flooding

• Where does flooding occur?

• When does it occur?

• Why does it occur?

• How does it occur?

Flood Plain ManagementDefinitions:

Flood Plain: “An area, usually low lands adjoining a watercourse, that has been or may have been covered by flood waters.”

Regulatory Flood Plain: “The Regulatory Flood Plain is the approved standard used in a particular watershed to define the limit of the flood plain for regulatory purposes pursuant to the Provincial Flood Plain Planning Policy Statement. Within TRCA’s jurisdiction, the Regulatory Flood Plain is based on the Regional Storm%”

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Causes of Floods

• Rain Storm : temperate cyclone, tropical cyclone, convective rain, steady rain

• Snowmelt

• River ice breakup

Rough Location of Top of Bank(with vertical exaggeration)

Delineating Top of Bank – Valley Corridor

Regional

Storm

Flood

10 M Buffer

(from top of

bank)

Municipal

Setback

T.O.B.

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Valley Corridor

Stream Corridor

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F02_07

Boundaries of watershed can be identified by locating the

lowest point on the map

Floods

• When water at river’s bank: full stage alert

– stages above: damage occurs

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Typical Watershed

Tributary 1

(Flow Point A)Tributary 2

(Flow Point B)

Flow Point C

Lake Ontario

Watershed boundary

Source: Georgia Stormwater Manual, 2001

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Flooding in Ontario

Flooding

• In riverine and lake centred watersheds, a

number of factors effect the flows within our

watercourses.

• There are two broad categories of surface

water conveyance and storage systems.

• Temporal scale very important for flooding.

• The ‘worst’ flooding requires many different

precursors to be present.

Flooding - Approach

• Flooding is managed in very different ways across Canada and globally.

• In Canada, there is no overarching framework for floodplain management and flood risk management..

• Globally, flooding is dealt with through many different approaches.

• Ontario has some of the most stringent requirements in the world.

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Flooding in Ontario

• In Ontario, the approach is to eliminate loss of

life and property.

• In other areas, utilize floodproofing

measures.

• In the United States, a approach is

utilized.

Flooding in Ontario

• Where did Ontario’s requirements come from,

and how are they implemented?

• Conservation Authorities Act 1946.

• Hurricane Hazel (southern Ontario) 1954

Hurricane Hazel (1954) is the

Largest Storm Event on Record in

TRCA’s Jurisdiction. It is the

therefore the Regulatory Event

used in Floodplain Delineation as

Prescribed by the Province

Hurricane Hazel, Oct. 15-16, 1954

Dundas Street

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Woodbridge

Raymore Drive

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High Water Mark,

Raymore Drive

Humber River South of Dundas Street

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How is Floodplain management implemented in

Ontiario?

Two Complementary Layers to Flood

Hazard Management in Ontario

• Planning Act

• Conservation Authorities Act:

– Manage downstream flood impacts and mitigate impacts

through the development process

• Development Regulations (Provincial)

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• Planning Act – governs new development in

Ontario.

• Identifies that decisions of a planning

authority must be consistent with the policy

statements issued by the Province.

• Last Provincial Policy Statement (PPS) 2005.

Identifies the framework for planning, and

development within floodprone areas.

Provincial Policies

• Provincial Policy Statement (PPS) 2005

– 3.1 “Natural Hazards”

• Ministry of Natural Resources (MNR) “Technical Guide –River and Stream Systems: Flooding Hazard Limit”

Conservation Authorities Act

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What is a Floodplain?

TRCA Jurisdiction

•Rouge River

•Petticoat Creek

•Duffins Creek

•Carruthers Creek

The TRCA's area of jurisdiction includes:

•3,467 sq. km: 2,506 on land and 961 water-based.

This area is comprised of nine watersheds including:

The TRCA’s jurisdiction also extends into Lake Ontario to a point defined by the Territorial Divisions Act, R.S.O. 1980

•Etobicoke Creek

•Mimico Creek

•Humber River

•Don River

•Highland Creek

The population in 2004 within TRCA’s jurisdiction is approximately 4,300,000

(37% of Ontario’s population).

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OBJECTIVES:

•To prevent the loss of life •To minimize

property damage

TRCA’s Mandate & Jurisdiction

(Flooding)

Sources of Authority:

• Conservation Authorities Act

• Ontario Regulation 166/06

• Planning Act

• Provincial Policy Statement (S. 3.1 & 2.3)

• Delegated Review Responsibility – Provincial,

Regional, and Local through MOUs and Agreements.

• Other Provincial Acts (EA, ORM, NEC)

Ontario Regulation 166/06

� In response to hazard management through the

development process

� Established the regulatory control of the Conservation

Authorities

� Requires permit from the Conservation Authority to:

�Construct in a Flood Plain

�Place fill in a Regulated Area

�Alter a watercourse (TRCA must screen for DFO permit)

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Valley and Stream Corridor Management Program

� Adopted on Oct. 28, 1994

� Superceded various other MTRCA policy documents

� Primary Objectives:

� To prevent, eliminate or reduce risk to life and property from flooding, from erosion of river banks, and valley slope instability;

� To protect and regenerate ecological health and integrity of these systems; and

� To provide opportunities for compatible public use and enjoyment.

� Serves as the criteria for reviewing all applications before the TRCA including permits

Continued…

VSCMP Policies

Development boundaries for valleys:

If the slope is stable, a minimum of 10-metres inland from the top of bank

For Stream Corridors:

10 metres from the Regulatory Floodplain.

What is a Flood Plain?

“An area, usually low lands adjoining a watercourse, that has

been or may have been covered by flood waters.”

How Do We Delineate Floodplains?

All procedures used by TRCA are required to be compliant with the Ministry of Natural Resources “Flood Plain Management in Ontario - Technical Guidelines”

Key Components to Developing Flood Lines:

1.Hydrology

2.Hydraulic Modeling

3.Flood Plain Mapping

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Managing Development In Existing Flood-prone Communities

Special Policy Areas

� Exceptions to allow development within valley and stream corridors

may be permitted when fully demonstrated that prohibition would

have serious economic and social health impacts on an existing

flood prone community

� In such cases development must satisfy criteria that generally

require floodproofing, and safe ingress and egress

� It is recognized that in some valley corridors, the boundaries of

these established communities extend beyond the flood plain and

in such cases the SPA principles should be applied even when

outside the SPA boundary.

• Criteria throughout TRCA jurisdiction has been established through detailed hydrology studies for each watershed

• Flow criteria map illustrating the types of control required, unit flow rates and flow targets at key locations will be provided

Flood Flow Criteria

Hydrology Modeling

How much water flows down the river during various storm events

1. TRCA has completed Hydrology Studies for each of the 9 watersheds

2. Hydrologic computer models were developed that include physical parameters such as:

• Watershed area

• Land Use / Geology

• River Length

3. Metrological (stream and rainfall data) is added to the model to determine flow rates

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3 ESSENTIAL COMPONENTS OF

FLOODPLAIN MANAGEMENT

•Prevention

•Protection

•Emergency

Response

•Land use planning and

•e.g. Flood & fill line mapping

(preferred approach)

•Regulation of development

•Structural measures

•Acquisition

•Flood warnings

TRCA Flood Plain Management and Mapping Program

Valley and Stream Corridor Management Program (VSCMP)

� Sets out development guidelines for properties influenced by valleys and stream corridors

� The overall objective of the VSCMP policies are to:

� prevent development from occurring within areas that may introduce risk to life and property associated with flooding, erosion, and slope stability, or that is not compatible with the protection of these areas in their natural state

� prohibit new development within the Regulatory Flood Plain

� regulate existing development activities within the Regulatory Flood Plain (eg., one zone and SPA’s)

Carruthers Creek Watershed Flows

12.9321.73 28.68

38.17 45.69 53.81

220.26

0

50

100

150

200

250

2 Year 5 Year 10 Year 25 Year 50 Year 100 Year Regional

Flow Rate (m3/s)

Flood Frequency (years)

Frequent Infrequent

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0

200

400

600

800

1000

1200

1400

1600

1800

normal 1 2 5 10 50 100 Hurricane

Flood Frequency (years)

Flow Rate (m3/s)

Don River Watershed Flows

Hydraulic Modeling and Mapping

1. TRCA has competed “River Hydraulic” studies for all 9 watersheds

2. Computer models were developed to determine water surface elevations, key model parameters:

– Flows (Hydrology)

– River Cross Sections (including bridges and culverts)

– Physical Parameters of the river (roughness, crossings)

3. Water surface elevation for Regulatory Storm plotted on base mapping

4. High mapping standards are required as per Provincial requirements

5. All map sheets are certified by a Licensed Professional Land Surveyor and Professional Engineer

Obtaining Flood Water Elevations to Define the Extent of the Floodplain

Flood Plain Map

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Flood Plain Mapping Index – over 500 map sheets

Flood Vulnerable Areas

Within TRCA

46 Flood Vulnerable

Areas Within TRCA

Jurisdiction

Lower Carruthers Creek - 1986

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Lower Carruthers Creek - 2009

Black Creek – Finch Ave. (Aug. 19/05)

Flood Management

• Regulate Development in Flood Plains

• Regulate Development Outside Flood

Plains (Storm Water Flood Flow

Requirements)

• Flood Warning Program – Public Safety

Messages and Emergency Management

• Flood Mitigation (Lower Don Lands Class

EA, Black Creek Stormwater Optimization

Study)

• Update hydrology and floodline mapping

for proposed growth (outside of urban

boundary and intensification within urban

areas)

Daily Flood Warning Operations

• High Water Safety Bulletin

• Flood Advisory

• Flood Warning

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Flood Control Infrastructure

Within TRCA

26 Flood Control

Structures Managed

By TRCA

• 10 Dams

• 13 Channels

• 3 Levee/Dyke

Systems

FLOODPLAIN MANAGEMENT

UPPER HUMBER RIVER HYDROLOGY MODEL

Caledon Area

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MODEL CALIBRATION

•Currently updating hydrology model

•model calibration based on current stream flow and rainfall data

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5 0 5 10 Kilometers

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HUMBER RIVER WATERSHEDHUMBER RIVER WATERSHED

Precipitation Gauge Locations

Legend:

Caledon

Mono

Adjala-Tosorontio

Brampton

Vaughan

King

P E E L

Y O R K

D U F F E R I N

S I M C O E

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#S Town of Richmond Hill

#S City of Toronto

#S City of Vaughan

%U Peel Region

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$T TRCA

STORMWATER MANAGEMENT CRITERIA

•Tributary based stormwater management controls

A TYPICAL DIGITAL FLOODPLAIN MAP

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A DIGITAL FLOODPLAIN MAP OVER A DIGITAL ORTHO PHOTO

TRCA’s Flood Plain Management and Mapping Program

Example of TRCA Updated

3-D Digital Flood Plain

Mapping

Daily Operations

• High Water Safety Bulletin

• Flood Advisory

• Flood Warning

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Flood Control Infrastructure:

Large Dams

Claireville Dam G. Ross Lord Dam

G. Ross Lord Dam

Structural Flood Protection Works

G. Ross Lord Dam – constructed

1973

Pickering / Ajax Dyke - constructed

1983

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How often are messages issued?

2008 Messages

0

1

2

3

4

5

Jan

Feb

Mar

AprMay Ju

n JulAug

Sep

Oct

Nov

Dec

18 Bulletins

4 Advisories

1 Warnings

2006 Messages

0

1

2

3

4

5

Jan

Feb

Mar

Apr

May Ju

n JulAug

Sep

Oct

Nov

Dec

19 Bulletins

8 Advisories

0 Warnings

2005 Messages

0

1

2

3

4

5

Jan

Feb

Mar

Apr

May Ju

n Jul

Aug

Sep

Oct

Nov

Dec

16 Bulletins

13 Advisories

1 Warning

2007 Messages

0

1

2

3

4

5

Jan

Feb

Mar

Apr

May Ju

nJulAug

Sep

Oct

Nov

Dec

8 Bulletins

3 Advisories

0 Warnings

Flood Centre

Website

The TRCA Operates a

Network of Climate and

Stream Flow Monitoring

Location

ForecastingMonitoring WarningThe TRCA Continually

Tracks Storms and

Weather Alerts to Predict

When and Where

Flooding may Occur

The TRCA is Responsible

for Sending Flood

Warnings and

Coordinating with

Emergency Response

72 Hour Emergency

Preparedness Kit

Photo Gallery

Submit a Photo

What You Should Know

Be Prepared

Education

Flood Forecasting RSS Feed

Preparing for a flood

What Watershed Am I In?

River Information

TRCA Education Programs

Frequently Asked Questions

Flood Safety Tips

Flood Warning

Emergency

Contacts

Flood Documents

Flooding on Roadways

TRCA’s Flood Control Structures

TRCA Flood Projects

Flood Links

NEXFLOODWatershed Response

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Automated PollingAutomated Polling

Collection and Monitoring Collection and Monitoring

DataData

Flood Forecasting System

Database Storage System

Email and Telephone Alert

System

www.trcagauging.caReal Time Gauging Network

Real Time Gauging Station Photos

Website Demonstration

http://www.trcagauging.ca

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Does significant flooding happen in

Ontario?

August 19, 2005 GTA

FLOODING

Location: Don River, Dufferin and Steeles Ave. (Aug. 19/05)

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Storm Event Information

• Weather system moved into

our area after 4:00 AM on Friday

August 19th.

• The morning storm cell passed

through TRCA jurisdiction over a

5 hour period from

approximately 4:00 AM to 9:00

AM.

• The afternoon storm cell

passed through jurisdiction over

a 4 hour period between 2:00

PM and 6:00 PM

• The most intense rainfall

generally occurred in the

afternoon between 3:00 PM and

5:00 PM

• The final radar image

represents the hour of 4:00 PM

Radar Image from King City Station - 1 Hour Corrected Total Depths (mm)

Storm Event InformationRecorded Daily Rainfall Depths at Available Gauges for August 19th

• From TRCA gauges the

minimum measured rainfall

depth was approximately 17

mm at Goodwood Pumping

Station (5.8 mm for the

morning event and 11.2 mm

for the afternoon event)

• From TRCA gauges the

maximum measured rainfall

depth was approximately 123

mm at TRCA – York Green

Roof (18 mm for the morning

event and 104.6 for the mm

afternoon event)

• Average measured rainfall

depth approximately 73 mm

(11 mm for the morning

event and 62 mm for the

afternoon event)

TRCA – Green Roof

Goodwood Pumping Station

Storm Event InformationMaximum Hourly Rainfall Intensity Recorded Available Gauges on August 19th

• Minimum measured hourly

intensity approximately 6

mm/hr at Goodwood

Pumping Station

•Maximum measured hourly

rainfall intensity

approximately 99 mm/hr at

TRCA -York Green Roof

Rain Gauge IDF and Total Depths

Analyzed

Historic Rain Gauge IDF and Depth

StatisticsToronto City Centre Gauge

Laidlaw Bus Depot

TRCA – Green Roof

Dufferin Reservoir

Markham Centre

Petticoat Creek CA

Ajax Works Yard

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Toronto City Rain Gauge - Return Period IDF Comparison

1.0

10.0

100.0

1000.0

1 10 100 1000 10000

Time (Minutes)

Intensity (mm/hr)

2-Year

10-Year

25-Year

50-Year

100-Year

TRCA Head Office (York

University Green Roof)Petticoat Creek CA

Dufferin Reservoir

Markham Tow n Centre

Laidlaw Bus Depot

Ajax Works Yard

Storm Event InformationRainfall IDF Curves - Comparison at Several Rain Gauge Locations for August 19th Storm

• Afternoon Storm Event on

August 19th. IDF curves derived at

selected stations. Values

exceeded 100-year return period

IDF curve at historic Toronto City

rain gauge

5 Minutes to 3 Hours

Toronto City Rain Gauge - Total Event Depth Comparison

Petticoat CA

Dufferin Reservoir

Toronto Head Office (Green

Roof)


Laidlaw Bus Depot

Ajax Works Yard

0

20

40

60

80

100

120

1 10 100

Return Period (Year)

Rainfall Depth (mm)

Toronto City - 24 Hour Depths

Toronto Head Office (Green Roof)

Petticoat CA

Dufferin Reservoir


Laidlaw Bus Depot

Ajax Works Yard

Storm Event InformationRainfall Depths - Comparison at Several Rain Gauge Locations for August 19th Storm

• August 19th afternoon 3 hour

storm event depths derived at

selected stations. Note that

several stations during the storm

event exceed the Toronto City

Rain Gauge 24 Hour – 100 Year

return period depth

Summary of Actions by TRCA Flood Warning

Staff

• 10:30 AM August 19th, 2005 - Flood Safety Bulletin Issued

• 3:15 PM August 19th, 2005 - Flood Advisory

Issued

• 8:30 PM August 19th, 2005 - Flood Warning Issued

• 10:00 AM August 20th, 2005 - Flood Warning Cancelled

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Flood Event InformationNotable Photos of Flood Locations

Black Creek at Rockcliffe Blvd

G. Ross Lord Reservoir

Black Creek at Highway 7

Highland Creek at Cedarbrae Park

Jersey Creek at Pine Valley Drive

Flood Event Information

Location: Jersey Creek at Intersection of Pine

Valley Drive and Embassy Drive – Looking North

at Flooding Through Intersection


Location: West Don River at G. Ross Lord Dam

and Reservoir – Looking East at Outlet Structure

and Reservoir Flood Depths

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Location: Highland Creek East of Bellamy Road in

Cedarbrae Park – Flooding Across Pedestrian

Bridge


Location: Black Creek at Rockcliffe Boulevard – Flood

Control Channel

Flood Event InformationLocation: Black Creek at Jane Street and Highway

7 – Looking East at Flooding of Road and

Commercial Development

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Flood Event InformationNotable High Water Level Locations and Erosion/Infrastructure Damage

Don River at Todmorden

Morningside Tributary at Seasons Drive

Black Creek at Finch Avenue

Highland Creek at

Morningside Park

East Don River at York Mills and Don Mills

Krosno Creek at Sandy

Beach Road

Miller Creek at Westney

Road

Highland Creek at

Ellesmere Rd.

Highland Creek at

Morningside Ave.

Flooding

Erosion


Location: Miller Creek at Westney Road – Flood

Flows Reached Underside of Bridge

Recorded High Water Level Location


Location: Krosno Creek at Sandy Beach Road –

Note Erosion at Sanitary Sewer Easement Over

Creek


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Location: Morningside Tributary at Seasons Drive

– Looking at Debris Located on By-Pass Structure

to Rouge River



Location: Highland Creek at Morningside Avenue



Location: Don River at Todmorden – Note Water

Survey of Canada Stream Gauge and High Water

Level


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Location: Highland Creek at Morningside Park –

Note the Extensive Erosion of the Valley Near

the Sanitary Trunk Sewer Break

Recorded Erosion Site


Location: Highland Creek at Ellesmere and

Birkdale Road – Note Extensive Bank Erosion



Location: East Don River at York Mills and Don

Mills – Note Damage to Concrete Channel Lining


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Location: Black Creek at Finch Avenue – Note

Complete Failure of Embankment and Roadway


TRCA On-Going Activities

• Post-Event Documentation, Analyses and Reporting

• Assessing High Water Mark Information and Current Flood Plain Mapping

• Completing Detailed Hydraulic Modelling at Critical Locations (eg. Black

Creek at Finch Avenue)

• Flood Response Follow-Up with External Agencies (Municipalities, Insurance

Industry, Adjacent CA’s and MNR)

• Preparation of Documentation Report

• Completion of Dam Operational Update for G. Ross Lord Dam and Updated

Emergency Plans at both G. Ross Lord Dam and Claireville Dam (MNR- WECI

Project)

• Completion of Remedial Capital Works Prioritization Database For TRCA Flood

Protection Infrastructure (MNR-WECI Project)

• Continued Discussions With Environment Canada Towards Undertaking a Joint

Formal Documentation of the Storm

Estimated Peak Flows

• Don River at Todmorden Mills

- Average Flow for August = 3.33 m3/s

- Peak Flow on August 19, 2005 = 180 - 200 m3/s

• Black Creek at Scarlett Road



• Malvern Branch of Highland Creek at Sheppard Ave



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Location: Black Creek at Highway 7

Recorded Flooding Site


Location: Highland Creek at Bellamy Road



Location: Highland Creek at Ellesmere and Birkdale Road


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Location: Highland Creek at Midland and Progress Avenue


Flooding (Aug. 19/05)

Location: Highland Creek East of Bellamy Road in

Cedarbrae Park – Flooding Across Pedestrian

Bridge


Location: Highland Creek at Ellesmere and

Birkdale Road – Note Extensive Bank Erosion

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Location: Highland Creek at Ellesmere and Birkdale Road


Location: Black Creek at Highway 7


Location: Black Creek at Finch Avenue – Note

Complete Failure of Embankment and Roadway

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Prevention &

Mitigation Preparedness

Response Recovery

2008 Events

July/August, 2008 Durham Storms

Departure From Normal (%)

Total Monthly Rainfall - Pearson Airport

-150.00

-100.00

-50.00

0.00

50.00

100.00

150.00

200.00

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Jan

Feb

Mar

Apr

May

Jun

Jul

200720062005 2008

June 23, 2008 Flood Warning

Lower Don River May 13, 2000

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Don River, Dufferin and Steeles Ave

Black Creek, Jane Street at Highway 7

Don River, Woodbine and Steeles

Brampton SPA next class – How to manage in

communities that already exist in the

floodplain.

• Hazel’s Legacy

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Flooding in Other Areas

www.thespec.com

Red River, 1997

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Australia Floods, 2011

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53

http://www.youtube.com/watch?v=y_qRf_u0hbE&feature=youtube_gdata_player

http://www.youtube.com/watch?v=5NJzamfavmg&feature=related

http://www.youtube.com/watch?v=Sim6jynDndc

Australia Flooding 2011

Pakistan Flooding 2010

Pakistan flooding 2010

http://www.youtube.com/watch?v=JUMmUNWqM68

http://www.youtube.com/watch?v=OkP0lRLu0lE&feature=fvwrel

http://www.youtube.com/watch?v=t-KgXYKWliQ&feature=relmfu