1

Working Session #2

Alternatives

August 23, 2005

Website: http://www.trca.on.ca/water_protection/don_mouth/default.asp?load=whats_new

Phone: 416-661-6600 ext. #5280

2

What we have accomplished to date……

• Public Forum #1

– Introduced the project

– Outlined the projects goals and objectives

• Working Session #1

– Presented information on issues and studies

– Obtained feedback on what additional information might be obtained

• Site Walk

3

Highlights of the Site Walk

4

Highlights of the Site Walk

5

Meeting Purpose

• To review the EA process

• To provide an overview of why and how alternatives

are considered as part of an EA

• To present the “alternatives to” which have been

identified

• To present the framework for the identification of

alternative methods

• To learn from the public what additional information should be considered

6

EA Process – Two Steps

The key difference between a ToR and carrying out the EA is:

• The ToR outlines what will be done and how it will be done

• During the EA, the process described in the ToR will

be carried out.

Doing itDoing itWhat will be done What will be done

and howand how

7

General Content of an EA Terms of Reference

• In general, a ToR should

1. Identify the purpose of the proposed undertaking

2. Provide a general description of the proposed undertaking

3. Provide a general description of the environment that may be potentially affected in the EA

4. Outline the alternatives that will be considered in the EA

5. Identify how alternatives will be evaluated and how a preferred is chosen

6. Describe the consultation that will take place during preparation of the EA

7. Outline other approvals that may be required and the proposed schedule

• Consultation between the proponent and interested parties is required as part

of preparing a ToR

8

Project Purpose –Goals and Objectives

� Goal

� To establish and sustain the form, features, and function of a natural river

mouth within the context of an urban environment.

� Objectives

� Naturalize the Mouth of the Don River Mouth

� Provide Flood Protection

� Manage operation of the river (sediment, debris and ice management)

� Integrate existing infrastructure functions that could not be reasonably

moved. (including road, rails, utilities, trails, and power)

� Support additional compatible recreational, cultural, and heritage

opportunities

� Coordinate with other planning efforts for the revitalization of the waterfront

and associated certain and reasonably foreseeable infrastructure

9

Project Schedule

10

Key Definitions

• Naturalization - permitting natural, sustainable ecosystem functions to control a natural area

• Alternative to – alternative ways of carrying out the project – in our case each way is defined by an

alternate discharge point

• Alternative method – the development of each “alternative to” through the combination of “building

blocks” into systems which represent the form, function and features of a natural river mouth.

11

Key Definitions ……continued

• Wetland - a natural area that is saturated with water

long enough to create soils typical of flooded conditions that are dominated by greater than 50%

wetland plants

12

Key Definitions ……continued

• Discharge point - the convergence of the river’s flow with the lake

13

What you have told us that influences “alternatives”?

• add an “alternative to” that extends the Don River through the Ship Channel to the Outer Harbour

• add an “alternative to” that sends the Don River east towards Ashbridges Bay

• provide more explanation of what is meant by “alternatives to"

• language needs to be consistent, easy for the public to understand, and tied back to the project goal and objectives

• a slide on EA vocabulary and definitions would be helpful

14

What types of alternatives do we evaluate?

• The Ontario Environmental Assessment Act requires the identification and evaluation of

– “alternatives to” the undertaking –functionally different ways to solve the identified problem including the do nothing alternative – in our case based on alternative discharge points

– “alternative methods” – functionally similar ways to implement a preferred “alternative to” – in our case the development of each “alternative to” through the combination of forms and features to create the functions of a natural river mouth .

15

Past Efforts to Identify Alternatives

• Over a number of years different concepts for naturalizing the Mouth of the Don River have been

proposed by individuals, stakeholder groups, etc.

• All of these concepts have been attempts to develop

a more natural form of river mouth and create

terrestrial and aquatic habitat.

• These previous concepts incorporate both

“alternatives to” and “alternative methods”.

16

Level of Detail for ToR

• the “alternatives to” to be evaluated in the EA will be presented

• the framework for the identification of “alternative methods” not the alternative methods themselves will

be presented

17

Naturalization

Study Area

18

“Alternatives to”

• The “alternatives to” selected were based on the river’s discharge point to the lake

• The alternatives selected are representative of those put forward in the past

• The “alternatives to” will be evaluated to determine

which ones will be presented in the ToR. This will be discussed at Working Session #3

19

Alternatives To

3. River with discharge

through the Port

Lands

1. Do Nothing

2. River with discharge to

the inner harbour

4. Combination of

Discharge Point

(Primary and

Regional flood

Overflow)

Alternatives To

20

Alternative Methods

• “Alternative methods” will be identified by combining different forms and features required to create the functions of a natural river mouth

• The identification of “alternative methods” gives prime consideration to naturalization and flood protection

• Other project objectives will be addressed as subsequent refinements to the “alternative methods”

21

Functions of a Natural River Mouth

• The river and its functions are influenced by the upstream reaches of the watershed and the lake.

• Examples of river mouth functions include:

– sediment storage/transport

– linkages to upstream

– flood conveyance/storage

– aquatic/terrestrial habitat

– water quality control

– debris management

22

River Mouth Relationship to River and Lake

River Mouth

(area influenced

by lake levels)

23

The river provides a conduit of nutrients, stable thermal conditions and connection between the lake and the watershed

River Mouth Relationship to River and Lake

24

Back water lagoons are principal areas of production and provide a variety of essential habitats

River Mouth Relationship to River and Lake

25

River discharge areas are commonly very productive littoral habitats

River Mouth Relationship to River and Lake

26

The river mouth wetland complex is an essential habitat for the entire waterfront.

River Mouth Relationship to River and Lake

27

Developing “Alternative Methods”

• Each “alternative method” will combine forms and features of the river and its mouth to create functions which meet the objectives set for the project

– Forms –shape, size, physical setting (in terms of soils, physiography, subsurface geology, topography, river channel width, water depth etc)

– Features – components, both organic and inorganic, that are characteristic of a natural area (e.g., species wildlife, plants and vegetation communities, trails, etc)

– Functions - processes, products or services that are created by combining forms and features (e.g. Wildlife habitat, sediment storage, water quality improvement)

FORMS + FEATURES = FUNCTIONS

28

Examples

Forms• Channel morphology

– Slope

– Hydraulic geometry

– Channel structure

– Sinuosity

– Number of channels

– entrenchment

– Estuary (lacustrian form)• Wetlands

• Sheltered embayment

– Deltas• Fan

• Barrier beach

• absence

• Flood control works– Dykes

– Berms

– Floodwalls

– Dredging

Features• Habitat types and distribution

• Sediment grain size

• Infrastructure– Causeways/viaducts

– Bridge spans

• Floodplain • Topography

• configuration

29

Preliminary List of Desirable River Mouth Functions

1. Control of flow rate

2. Wildlife Habitat

3. Sediment management

4. Debris management

5. Flood risk reduction

6. Habitat connectivity

30

Examples of Form + Feature = Function

++ ==

Form Form Feature Feature FunctionFunction

Could be a:Could be a:

•• Flood Protection functionFlood Protection function

•• Naturalization functionNaturalization function

•• Other kind of ecosystem functionOther kind of ecosystem function

31

Examples of Form + Feature = Function

==

A number of different A number of different

forms + features forms + features

combine to deliver a combine to deliver a

number of different number of different

ecosystem functionsecosystem functions

A number of different A number of different

functions combine to make functions combine to make

an “Alternative Method”an “Alternative Method”

++

32

Examples of Forms + Features = Functions

FUNCTION

•Provide submergent and

emergent vegetation

communities

•Swamp sparrow habitat

•Fish foraging and spawning

habitat

•Adaptable design over a range

of lake and river water levels

Submergent

marsh

Undulating

topography

ranging from 0.5 m

above and 1m

below mean lake

level

Non-permanent

flood control

structure due to

possible risk of

failure

Flood

protection

structure

Dyke

FLOOD PROTECTION

NATURALIZATION

FEATUREFORM

33

Identifying the Long List of “Alternative Methods”

• A preliminary long list of “alternative methods” will be developed by combining a series of different forms, features, and resulting functions.

• This long list of “alternative methods” will be subjected to a technical screening which will assess which ones have the ability to meet the associated technical criteria for the naturalization and flood control objectives.

• The technical screening criteria will be developed.

34

Screening of Conceptual Alternative Methods

• Technical screening will eliminate from the long list those “alternative methods” that do NOT work

technically

• For the remaining short list of “alternative methods”

focus on more detailed refinement (development) and

evaluation by addressing the other project objectives related to operational management, integration with

infrastructure, and recreation and cultural opportunities.

35

Refinement of Short List of Alternative Methods

• The short list of “alternative methods”

– will be refined based on the results of the technical screening;

– will address issues related to operational management;

– will address opportunities to influence existing infrastructure through other EAs/planning processes underway such that the DMNP is made better;

– will identify opportunities for recreation; and

– will identify opportunities to enhance cultural and heritage resources.

36

Summary of Process to Identify “Alternative Methods”

1. Identify forms and features which combine to deliver individualfunctions that meet the Naturalization and Flood Protection Objectives for the project

2. Identify different combinations of functions that will enable the project to meet the Naturalization and Flood Protection Objectives

3. Identify the long list of “Alternative Methods” to be considered

4. Complete a Technical Screening of the Long List to eliminate Alternative Methods that DO NOT work technically

5. Refine the Short List of “Alternative Methods” to identify opportunities to meet other project Objectives (e.g. recreation,infrastructure, culture and heritage, etc.)

37

Next Steps

• Next working sessions

– September 7, 2005 Evaluation and Public Consultation

38