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Hamilton West Harbour Shoreline and Breakwater Class Environmental Assessment: Environmental Study Report
April 17, 2013
Dillon Consulting Limited Page 70
8.0 BREAKWATER IMPROVEMENTS
8.1. Breakwater Alternative Solutions (Class EA Phase 2)
As discussed in Section 4.3.3, a breakwater reduces on-shore wave activity and assists in the reduction of
on-shore flood hazard. Breakwaters also provide protection to boats moored on off-shore docks. The main
basin is the area housing the greatest number of boats and it is the most open to wave action. This section
of the report specifically addresses the breakwater for the main basin.
8.1.1. Breakwater Alternative Solutions
The alternative solutions must primarily address the wave conditions within the basin. The wave
conditions must be reduced to an acceptable standard. A wave height of less than 0.3 m is generally
considered to be an acceptable wave agitation within a marina basin within the boating season.
Breakwaters must also be able to withstand wave and ice conditions at the site.
A “do-nothing” alternative would continue use of the existing breakwater. Floating breakwaters function
by reducing the wave energy that can be transmitted through and under the structure, thus reducing the
wave height on the back (sheltered) side of the breakwater. The design of a floating breakwater is
primarily governed by wave period. Floating breakwater structures become very inefficient when the
design wave period is exceeded. Continued use of the existing breakwater would provide adequate wave
reduction and protection for the existing mooring basin only up to the design wave period. This design
wave period will be exceeded periodically, as it has been in the past. When exceeded, the docks and boats
will be potentially subject to damage, as has occurred in the past. In addition, the length of the existing
breakwater is not sufficient to allow for future expansion of the marina basin, as envisioned under the
Waterfront Concept Plan. Thus, a “do-nothing” option was not considered further.
Alternative solutions to addressing the wave conditions within the main basin were identified and include:
Option 1: Repair Breakwater;
Option 2: New Breakwater – Fixed;
Option 3: New Breakwater –Floating.
Option 1: Repair Existing Breakwater
A review of the previously completed assessments that were carried out by others after the significant
damage to breakwater and docks in the early 1990s concluded that a replacement of the breakwater rather
than a repair is required. Due to the overall physical limitations of the existing structure, it is anticipated
that it cannot be upgraded to provide adequate wave reduction.
Option 2: New Breakwater – Fixed
A new fixed breakwater could be constructed along the outer perimeter of the expanded basin. Fixed
breakwater refers to structures that are placed on the lake bottom and are statically stable. The most
common type of fixed breakwater on the Great Lakes is a stone structure. Other types of fixed breakwater
could include steel sheet pile caisson, crib structures or H Pile with lagging.
Option 3: New Breakwater –Floating
A new floating breakwater can also be constructed along the perimeter of the expanded basin. Preliminary
assessment of wave climate at the location and review of commercially available floating breakwaters
indicates that suitable floating breakwaters exist. The type of breakwater likely to be utilized is a pontoon
type. These are most commonly concrete structures with integrated flotation systems. Pontoon
Hamilton West Harbour Shoreline and Breakwater Class Environmental Assessment: Environmental Study Report
April 17, 2013
Dillon Consulting Limited Page 71
breakwaters can be utilized as walkways or temporary docks. Other types of floating breakwaters can also
be design to provide the required protection.
A floating breakwater can be relocated should future plans for the marina basin size or shape be altered.
The most common type of anchoring system for a floating breakwater for water depths in excess of 10 m is
a concrete block connected to the breakwater with chain or cable. The concrete blocks can readily be
moved.
The interaction of floating breakwaters with ice is difficult to predict and potential for ice damage to a
floating breakwater exists. Potential for ice damage must be assessed based mostly on local experience and
experience of the manufacturer with their particular type of structure and design. Given that an “A” frame
floating breakwater existed at this location for nearly twenty years without notable ice damage suggests
that use of floating breakwater at this site is feasible.
8.1.2. Breakwater Evaluation and Preferred Solution
A detailed evaluation was completed to compare the advantages and disadvantages of each alternative
based on four principal evaluation criteria groups:
Natural environment considerations;
Socio economic and cultural environmental considerations;
Technical considerations; and
Relative cost considerations.
This evaluation if documented in Table 8.1 at the end of this Section and further discussed below based on
the criteria groups noted.
Natural Environment: Both floating breakwater alternatives (Option 1: Repair Existing Breakwater and
Option 3: New Breakwater - Floating) result in minimal impacts to the natural environment. In both cases
work will be required on the anchor system for the floating breakwater however this work is anticipated to
be short term and result in minimal long term disturbance to fish habitat. The fixed breakwater (Option 2)
is placed on the lake bottom and has a greater potential for loss of fish habitat than the floating structure. It
is noted however, that habitat can often be built into the breakwater structure itself. A fixed breakwater
will also impact water circulation within the main basin and water exchange between the main basin and
the Hamilton West Harbour area. The impact on water quality due to the change in circulation pattern
cannot be quantified without detailed modelling. From a natural environment perspective, a floating
breakwater is preferred. There is limited difference in natural environment benefits between Option 1:
Repair Existing Breakwater and Option3: New Breakwater - Floating.
Socio-Economic and Cultural: None of the three alternatives are anticipated to result in negative impacts
on the existing waterfront recreation or commercial facilities, public safety, or cultural heritage.
Regardless of the type of breakwater structure, there is a potential for impact on navigability but all
structures can be designed to minimize impact. From a socio-economic and cultural perspective, all
options are considered similar.
Technical: It is not anticipated that Option 1: Repair Existing Breakwater can result in a structural integrity
that can provide the appropriate level of protection to the main basin. So, from a technical perspective, this
option is least preferred. Considering construction of a new breakwater, a floating structure (Option 3) is
preferred over a fixed structure (Option 2) as it offers greater flexibility for movement to accommodate
changes in the docks within the basin.
Hamilton West Harbour Shoreline and Breakwater Class Environmental Assessment: Environmental Study Report
April 17, 2013
Dillon Consulting Limited Page 72
Cost: From a cost perspective, Option 1 – Repair Existing is the lowest cost. Option 2: New Breakwater –
Fixed has the highest cost (approximately $30,000/m) and Option 3 – New Breakwater – Floating has a
moderate cost (approximately $4,000/m). From a cost only perspective Option 1 is preferred.
The preferred option for the main basin breakwater is a new floating breakwater. It offers sufficient level
of protection from wave action with minimal impact on fish habitat and water circulation. It also offers
flexibility to accommodate changes to the docks4 and/or allow for public access and can be constructed for
a moderate cost.
4 The preliminary dock arrangement shown during consultation on this project within the basin is conceptual and was prepared for
the purpose of determining an approximate size of the water area required for the basin and to assist with the general layout and
configuration of the breakwaters. The preliminary dock layout is based on an average boat size of 10 m. The final dock layout will
be determined as the land side configurations are finalized, suitability of dock access points confirmed and operational aspect of the
boating facility confirmed.
Hamilton West Harbour Shoreline and Breakwater Class Environmental Assessment: Environmental Study Report
April 17, 2013
Dillon Consulting Limited Page 73
Table 8.1: Evaluation of Breakwater Types
Evaluation Criteria Option 1: Repair
Existing Breakwater
Option 2: New Fixed
Breakwater
Option 3: New Floating
Breakwater
Natural
Environment
Opportunity to
naturalize the
shoreline and improve
fish habitat.
None of the alternatives
impede the opportunity
to naturalize the
shoreline and improve
fish habitat.
None of the alternatives
impede the opportunity to
naturalize the shoreline
and improve fish habitat.
None of the alternatives
impede the opportunity to
naturalize the shoreline
and improve fish habitat.
Potential for impact to
aquatic or terrestrial
habitat during
construction.
May include some
improvement to the
anchor system but
overall low potential for
impact on existing
habitat expected.
Construction of a fixed
breakwater involves
depositing material on the
lake bottom resulting in
high potential for habitat
impact.
Construction of a new
anchor system but overall
low potential for impact
on existing habitat
expected.
Potential for water
quality improvement.
Involves construction
within the water and has
some potential for
impact to water quality
during construction.
Fixed breakwater
involved long
construction period within
the water and has high
potential for impact to
water quality during
construction.
Fixed breakwater will
impact the water
circulation pattern in the
harbour and has potential
to impact water quality in
the marina.
Involves construction
within the water and has
some potential for impact
to water quality during
construction.
Impact on Erosion. All of the alternatives
provide protection from
wave action and erosion
provided they are
constructed in
conjunction with
appropriate shoreline
treatment.
All of the alternatives
provide protection from
wave action and erosion
provided they are
constructed in
conjunction with
appropriate shoreline
treatment.
All of the alternatives
provide protection from
wave action and erosion
provided they are
constructed in
conjunction with
appropriate shoreline
treatment.
Natural Environment
Summary
Both floating breakwater alternatives (repair existing or replace with new
floating breakwater) result in minimal impacts to the natural environment
compared to the fixed breakwater which has the potential to remove fish habitat
and alter water circulation and possibly water quality in the marina.
Socio-Economic and Cultural Environment
Potential for impacts
on waterfront
recreational or
commercial facilities.
All alternatives will
have minimal impact on
existing shoreline and
on-shore facilities.
All alternatives will have
minimal impact on
existing shoreline and on-
shore facilities.
All alternatives will have
minimal impact on
existing shoreline and on-
shore facilities.
Hamilton West Harbour Shoreline and Breakwater Class Environmental Assessment: Environmental Study Report
April 17, 2013
Dillon Consulting Limited Page 74
Evaluation Criteria Option 1: Repair
Existing Breakwater
Option 2: New Fixed
Breakwater
Option 3: New Floating
Breakwater
Opportunity for
enhancement of
waterfront recreational
or commercial
facilities/ amenities.
All alternatives involve
improvement to the
protection of the land
and/or water and thus all
provide opportunities
for enhancement of
amenities.
All alternatives involve
improvement to the
protection of the land
and/or water and thus all
provide opportunities for
enhancement of
amenities. New fixed
breakwater may provide
an opportunity to provide
public access.
All alternatives involve
improvement to the
protection of the land
and/or water and thus all
provide opportunities for
enhancement of
amenities. New floating
breakwater may provide
an opportunity to provide
public access.
Potential for impact on
public safety.
All alternatives involve
improvement to the
protection of the land
and/or water and thus all
provide safety
improvement.
All alternatives involve
improvement to the
protection of the land
and/or water and thus all
provide safety
improvement.
All alternatives involve
improvement to the
protection of the land
and/or water and thus all
provide safety
improvement.
Potential to impact
cultural heritage
(archaeological
resources or built
heritage and cultural
landscapes) and/or
treaty rights.
Minimal impact on
cultural heritage or
treaty rights.
Minimal impact on
cultural heritage or treaty
rights.
Minimal impact on
cultural heritage or treaty
rights.
Impact on
Navigability.
All alternatives have
potential to impact
navigability. Care will
be taken to design the
breakwater to minimize
potential for negative
impact.
All alternatives have
potential to impact
navigability. Care will be
taken to design the
breakwater to minimize
potential for negative
impact.
All alternatives have
potential to impact
navigability. Care will be
taken to design the
breakwater to minimize
potential for negative
impact.
Socio-Economic and
Cultural Environment
Summary
All alternatives are similar in their potential for socio-economic and cultural
environment impact. A new breakwater provides the best opportunity for public
access.
Technical
Structural integrity It is not anticipated that
the existing breakwater
can be repaired to
provide adequate
protection for the
marina.
A new breakwater, fixed
or floating can be
designed to provide
structural integrity.
A new breakwater, fixed
or floating can be
designed to provide
structural integrity.
Level of protection
provided.
It is not anticipated that
the existing breakwater
can be repaired to
provide an appropriate
level of protection.
A new breakwater, fixed
or floating can be
designed to provide an
appropriate level of
protection.
A new breakwater, fixed
or floating can be
designed to provide an
appropriate level of
protection.
Design life/
Maintenance
requirements.
This alternative has a
minimal design life.
A new fixed breakwater
has a design life of
approximately 50 years.
A new floating
breakwater has a design
life of approximately 20-
40 years.
Hamilton West Harbour Shoreline and Breakwater Class Environmental Assessment: Environmental Study Report
April 17, 2013
Dillon Consulting Limited Page 75
Evaluation Criteria Option 1: Repair
Existing Breakwater
Option 2: New Fixed
Breakwater
Option 3: New Floating
Breakwater
Potential for
contamination issues
Minimal potential to
encounter
contamination issues as
only anchors on the lake
bottom.
Some potential to
encounter contamination
issues due to greater lake-
bottom disturbance.
Minimal potential to
encounter contamination
issues as only anchors on
the lake bottom.
Flexibility A floating breakwater
provides the most
flexibility as it can be
moved to accommodate
changes to the docks.
Additional new
breakwater needed to
accommodate expanded
marina basin.
A fixed breakwater is the
least flexible as the
structure cannot be
moved.
A floating breakwater
provides the most
flexibility as it can be
moved to accommodate
changes to the docks.
Potential impacts on
utilities.
Anchors can easily be
located away from any
utilities.
Cannot be located on top
of any utilities.
Anchors can easily be
located away from any
utilities.
Constructability Relatively easy to
construct.
Relatively easy to
construct.
Relatively easy to
construct.
Technical Summary The new floating breakwater is preferred as it provides more flexibility than a
fixed breakwater and the existing floating structure is not easily upgraded.
Cost
Relative cost
differences.
Lowest Cost. Highest Cost
(approximately $30,000
per m).
Moderate cost
(approximately $4,000
per m).
8.2. Breakwater Alternative Design Concepts (Class EA Phase 3)
Phase 2 of the class environmental assessment considered potential breakwater alternative solutions. The
alternative solutions included repair of the existing breakwater, replacement of the existing floating
breakwater with a new functional floating breakwater or replacement of the floating breakwater with a
fixed breakwater. The process concluded with a new floating breakwater being the preferred alternative
solution option due to a number of environmental advantages and a substantial capital cost advantage.
The alternative design concept stage work included further development of coastal design criteria and
further refinements of construction costs estimates and breakwater layout and configurations.
8.2.1. Coastal Assessment
A coastal assessment was completed including the development of wave climate for the breakwater
location for a full year and for a typical boating season. Boating season is considered to extend from May
15 to September 30. A wave hindcast was completed which looks at wind data from the last 30+ years to
determine the typical wave height, power and period. The winds used in the hindcast were from the
Hamilton Airport and covered a period of August 1971 to December 2011.
The results of the analysis are presented on Figures 8.1 and 8.2. Figure 8.1 indicates the directional
distribution of wave energy and wave heights. Generally, the hindcast shows that the largest winds and
waves in the west harbour come from the northeast with the second largest from the west. The directional
distributions are similar for the full year and the boating season. However, the full year shows a substantial
increase in wave height from the northeast and west quadrants. Figure 8.2 shows the exceedance of wave
Hamilton West Harbour Shoreline and Breakwater Class Environmental Assessment: Environmental Study Report
April 17, 2013
Dillon Consulting Limited Page 76
height and wave period for the hindcast period. The wave period was determined as it is a critical factor in
determining the performance a floating breakwater. The figures show that significant waves in the order of
1.2 m in height with a period of 4.1 seconds can be expected to approach the site from the most critical NE
direction during the year. The wave height and period are reduced to approximately 0.8 m and 3.4 seconds
during the boating season.
Wave scatter diagrams and other figures illustrating monthly and annual wave power distribution for full
year and a boating season hindcast are presented in Appendix D.
Figure 8.1: Directional Distribution of Wave Energy and Wave Heights (Full year)
Figure 8.2: Exceedance of Wave Height and Period (Full year)
North NE East SE South SW West NW North
0
5
10
15
20
25
30
35
40
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
Wave P
ow
er
(% o
f to
tal)
Wave H
eig
ht
(m)
Wave Height
% Wave Power
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5
0.0001
0.001
0.01
0.1
1
10
100
0 0.3 0.6 0.9 1.2 1.5
Excced
an
ce (
%)
Wave Height (m)
wave height
wave period
Wave Period (s)
Hamilton West Harbour Shoreline and Breakwater Class Environmental Assessment: Environmental Study Report
April 17, 2013
Dillon Consulting Limited Page 77
8.2.2. Breakwater Design Alternatives
The breakwaters that can function with the local wave environment are expected to fall into two basic
design types. These design types include an “A” frame design and a concrete pontoon design, although
other systems can be also designed for the site conditions.
A-Frame: Figure 8.3 shows an example of an A-
frame breakwater design. An A-frame type
breakwater includes an inverted “A” frame
structure with floats and an underwater frame that
supports a central baffle board that reflects wave
energy. Floats are typically constructed using steel
pipes. The breakwater is secured in its position
with steel chains connected to concrete blocks on
the lake bottom. The breakwater is typically made
up of a number of sections that are connected
together in a straight line to act as one unit. . This
design is the same type as currently used at the site.
However, the main components of the breakwater,
that is the spacing and size of the floats and the size
of the baffle board would need to be properly sized
to function under design conditions.
Concrete Pontoon: Figure 8.4 shows an example of
a concrete pontoon breakwater design. A concrete
pontoon design typically includes a main body of the breakwater which serves as floatation chamber. It is
typically a concrete shell that encloses a foam core. Underwater walls or baffles extend down along the
sides of the caisson. The top of the concrete can be dressed with timber or other products to provide
walking surface and fenders can be attached to the sides of the pontoon to accommodate fair weather
mooring. The breakwater is secured in its position with steel chains connected to concrete blocks on the
lake bottom. The breakwater is typically made up of a number of sections that are connected together in a
straight line to act as one unit.
Figure 8.4: Concrete Pontoon Breakwater
Figure 8.3: A-Frame Breakwater
Hamilton West Harbour Shoreline and Breakwater Class Environmental Assessment: Environmental Study Report
April 17, 2013
Dillon Consulting Limited Page 78
Both types of breakwater would be manufactured off-site and likely floated to the site from a remote
location. Both breakwater types have similar anchoring systems consisting of chain connecting it to
concrete blocks on the bottom of the lake.
Using the evaluation criteria developed early in the project, the alternative breakwater types were
evaluated. Table 8.2 at the end of this section shows the comparison for the two breakwater types for each
of the evaluation criteria. The following summarizes the evaluation based on each of the criteria groups.
Natural Environment – The anchoring system for both alternatives is similar and there is limited impact to
the aquatic environment for either alternative. Neither type of floating breakwater will result in a
significant change in water circulation. The existing breakwater occupies approximately the top 3 m of the
water column. The floating systems under consideration are not expected to occupy any greater portion of
the water column.
Socio-Economic and Cultural Environment – Both design types, i.e. “A” frame or concrete pontoon, are
well suited for application at this location. They can be designed to perform well within the wave climate
of the site adequately reduce the waves providing protection for the marina as well as an element of flood
protection for the shoreline features. Neither alternative will impact cultural heritage.
Technical – Both alternatives have a reasonable 20-40 year lifespan and are readily available5. The only
difference between alternatives relates to their ability to provide an opportunity for docking during special
events. The concrete pontoon breakwater can readily provide additional mooring for special events during
light wave conditions. It can potentially also provide pedestrian access if appropriate ramps are provided.
Public access to the main east breakwater would also require appropriate controls in place to restrict access
during times of severe weather. However, no decision regarding pedestrian access to the breakwater has
been made at this point by the City of Hamilton. The evaluation process assumes that no public access is
being provided.
Cost – Costs are expected to be similar, although the “A” frame design has not been manufactured locally
for some time and up-to-date prices from manufacturers are not available. It is anticipated that the cost for
both options would be in the range of $5,500 to $6,500 per metre.
Overall the breakwater types have very similar impacts and both would be appropriate for this location.
Since there is no clear preference between the alternatives, it is recommended that the determination of
breakwater type be based on the market response to minimum performance specifications set by the City of
Hamilton.
During final design, performance specifications should be set out in a document that describes in detail the
functional and physical properties of the breakwater desired. For example, the document would describe
the incident wave conditions the breakwater is expected to operate in with the maximum transmitted wave
conditions permitted. The document would also describe the materials permitted in the manufacture of the
breakwater and applicable standard material specifications, such as CSA or ASTM standards. This
approach is proposed as it allows manufacturers of various proprietary systems to respond to a tender call.
8.2.3. Breakwater Layout Alternatives
Two alternative breakwater entrance configurations were developed. These include a northeast facing
entrance:
5 The approximate lifespan of a floating breakwater as provided by the manufacturer is approximately 25 years. Based on
experiences including the current Hamilton floating breakwater, it can be assumed that with regular maintenance, the lifespan can
extend to 40 years.
Hamilton West Harbour Shoreline and Breakwater Class Environmental Assessment: Environmental Study Report
April 17, 2013
Dillon Consulting Limited Page 79
Option 1: Northeast Facing Breakwater Layout (Figure 8.5) – this option provides protection to
boats entering and exiting from the more frequent but smaller waves from the west; and
Option 2: Northwest Facing Breakwater Layout (Figure 8.6) – this option provides protection to
boats entering and exiting from the less frequent but larger waves from the east.
The configurations were developed to assist in the illustration and assessment of the function and costs of
the design concepts of the breakwaters. Each breakwater layout protects a marina basin designed to
accommodate up to 900 boat slips using a typical boat size of 9 m. The breakwater layouts are conceptual
only, as the final marina design will be undertaken as a separate project.
Both concept designs provide a main entrance 50 m wide. In addition to this wide entrance, access to the
basin can be potentially obtained around the ends of the two main breakwaters. The breakwaters are not
shore connected. Two secondary breakwaters are used in both concepts to control wave penetration through
the main entrance and to control waves diffracting around the tip of Pier 4. The layouts were developed to
provide protection for the ultimate marina size, minimizing breakwater lengths while providing sufficient
channels to allow boats to move properly. The criteria for selection of channel widths and marina entrance
are based on publications produced by the SCHB of the Department of Fisheries and Oceans and the US
Corps. of Engineers6
Figure 8.5: Option 1 – North East Facing Entrance Breakwater Concept
6 Small-Craft Harbor: Design, Construction and Operation, J. W. Dunham and A. A. Finn, Special Report No. 2, U.S. Army Corps.
Of Engineers, Coastal Engineering Research Center, December 1974. Planning Guidelines for Recreational Harbours in Ontario,
Small Craft Branch, Department of Fisheries and Oceans, prepared by Hough Stansbury, Woodland Limited, 1992.
Hamilton West Harbour Shoreline and Breakwater Class Environmental Assessment: Environmental Study Report
April 17, 2013
Dillon Consulting Limited Page 80
Figure 8.6: Option 2 – North West Facing Entrance Breakwater Concept
Using the evaluation criteria developed early in the project, the alternative breakwater layouts were
evaluated. Table 8.3 at the end of this section shows the comparison for the two breakwater layouts for
each of the evaluation criteria. The following summarizes the evaluation based on each of the criteria
groups.
Natural Environment – The layout of the breakwater will have no impact on the natural environment.
Socio-Economic and Cultural Environment – Both layouts provide adequate protection for the marina.
During the consultation process with stakeholders the boaters expressed a slight preference for the west
facing entrance.
Technical – There is no technical difference between the layout alternatives.
Cost – There is no cost difference between the layout alternatives.
Overall the differences between the layout alternatives relate solely to the type and frequency of wave they
protect against for boaters entering or leaving the basin. As noted above, during consultation boaters
indicated a slight preference for a west facing entrance so that there is protection from the less frequent but
larger waves coming from the east. Thus, overall Option 2: the northwest facing entrance is preferred.
It is noted that the layout concepts shown on Figures 8.5 and 8.6 were prepared for the ultimate marina
size. In reality, the size and operations of the marina will evolve over many years. Although the maximum
size is based on a market study incorporated in the Phase 1 Technical Report (Appendix A), it may take
many years before this capacity is achieved. If the breakwater is installed to far from the docks there is
Hamilton West Harbour Shoreline and Breakwater Class Environmental Assessment: Environmental Study Report
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potential for waves to be generated in the space between the docks and the breakwater. An assessment of
potential wave generation between the breakwater location and moored boats was undertaken to determine
the amount of open water that could exist between the docks and marina at this location. The results of this
assessment indicate that at the time of installation there should be no more than 100 meters of open water
between the breakwater and the floating docks.
To determine the final breakwater layout and location, the number of docks and approximate configuration
must be confirmed. It is recommended that a final decision regarding the location of the breakwaters
should be made at the time of final design and contract award.
Installation of the new floating breakwater will require approval of the Hamilton Port Authority. Other
agencies, such as the department of Fisheries and Oceans and Hamilton Conservation Authority should be
advised of the work. Their approvals may be required.
Hamilton West Harbour Shoreline and Breakwater Class Environmental Assessment: Environmental Study Report
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Dillon Consulting Limited Page 82
Table 8.2: Evaluation of Breakwater Design
Evaluation Criteria Option 1: A-Frame Option 2: Concrete Pontoon
Natural
Environment
Opportunity to
naturalize the
shoreline and improve
fish habitat.
No difference – neither alternative significantly
changes shoreline or fish habitat.
No difference – neither alternative
significantly changes shoreline or fish
habitat.
Potential for impact to
aquatic or terrestrial
habitat during
construction.
No difference – both alternatives have the
minimal impact on fish habitat as a result of the
anchoring system and no impact on terrestrial
habitat.
No difference – both alternatives have
the minimal impact on fish habitat as
a result of the anchoring system and
no impact on terrestrial habitat.
Potential for water
quality improvement.
No difference – both alternatives provide
adequate water circulation.
No difference – both alternatives
provide adequate water circulation.
Impact on Erosion. No difference – both alternatives will assist in
the reduction of on shore flooding and erosion
potential.
No difference – both alternatives will
assist in the reduction of on shore
flooding and erosion potential.
Natural Environment
Summary
Both alternatives will assist in reducing on-shore wave action and flooding and thus
erosion and neither will have a significant impact on fish habitat or terrestrial habitat.
Socio-Economic and Cultural Environment
Potential for impacts
on waterfront
recreational or
commercial facilities.
No difference – both alternatives will protect
recreation and commercial facilities.
No difference – both alternatives will
protect recreation and commercial
facilities.
Opportunity for
enhancement of
waterfront recreational
or commercial
facilities/ amenities.
Both alternatives will protect recreation and
commercial facilities.
Both alternatives will protect
recreation and commercial facilities.
Potential for impact on
public safety.
No difference – both alternatives will protect
recreation and commercial facilities.
No difference – both alternatives will
protect recreation and commercial
facilities.
Potential to impact
cultural heritage
(archaeological
resources or built
heritage and cultural
landscapes) and/or
treaty rights.
No difference – neither alternative will impact
cultural heritage.
No difference – neither alternative
will impact cultural heritage.
Impact on
Navigability
No difference – both alternatives provide
protection during storms and require navigable
waters protection act approval.
No difference – both alternatives
provide protection during storms and
require navigable waters protection
act approval.
Socio-Economic and
Cultural Environment
Summary
Both alternatives will protect the amenities at the waterfront.
Technical
Structural integrity No difference – both are suitable for site
conditions.
No difference – both are suitable for
site conditions.
Hamilton West Harbour Shoreline and Breakwater Class Environmental Assessment: Environmental Study Report
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Evaluation Criteria Option 1: A-Frame Option 2: Concrete Pontoon
Level of protection
provided.
No difference – both are suitable for site
conditions.
No difference – both are suitable for
site conditions.
Design life/
Maintenance
requirements.
No difference – both have a life of 20-40 years
and require the same maintenance.
No difference – both have a life of
20-40 years and require the same
maintenance.
Potential for
contamination issues.
No difference – both are in the same location
and contamination issues are not anticipated.
No difference – both are in the same
location and contamination issues are
not anticipated.
Flexibility Less suitable for boat docking but can be
modified for boat docking at an extra cost.
More suitable for boat docking.
Potential impacts on
utilities
No difference – neither alternative is likely to
impact utilities.
No difference – neither alternative is
likely to impact utilities.
Constructability No difference – both are straightforward to
construct.
No difference – both are
straightforward to construct.
Technical Summary Both alternatives have a reasonable design life and provide the same level of
protection. The Concrete breakwater provides a more suitable opportunity for
temporary boat docking should that be desirable.
Cost
Relative cost
differences.
Capital costs are similar for both alternatives
(approximately $4,000 per metre). Operation
and maintenance costs would also be similar for
both alternatives.
(Note: Budget pricing estimates presented in this
document are based on information supplied by the
manufacturer, SF Marine)
Capital costs are similar for both
alternatives (approximately $4,000
per metre). Operation and
maintenance costs would also be
similar for both alternatives.
(Note: Budget pricing estimates presented in
this document are based on information
supplied by the manufacturer, SF Marine)
Hamilton West Harbour Shoreline and Breakwater Class Environmental Assessment: Environmental Study Report
April 17, 2013
Dillon Consulting Limited Page 84
Table 8.3: Evaluation of Breakwater Layout
Evaluation Criteria Option 1: North-East Facing Entrance Option 2: North-West Facing
Entrance
Natural
Environment
Opportunity to
naturalize the
shoreline and improve
fish habitat.
No difference – neither alternative significantly
changes shoreline or fish habitat.
No difference – neither alternative
significantly changes shoreline or
fish habitat.
Potential for impact to
aquatic or terrestrial
habitat during
construction.
No difference – both alternatives have the
minimal impact on fish habitat as a result of the
anchoring system and no impact on terrestrial
habitat.
No difference – both
alternatives have the minimal
impact on fish habitat as a
result of the anchoring system
and no impact on terrestrial
habitat.
Potential for water
quality improvement.
No difference – both alternatives provide
adequate water circulation.
No difference – both alternatives
provide adequate water circulation.
Impact on Erosion. No difference – both alternatives will assist in
the reduction of on shore flooding and erosion
potential.
No difference – both alternatives
will assist in the reduction of on
shore flooding and erosion
potential.
Natural Environment
Summary
There is no difference between these alternatives from a natural environment
perspective.
Socio-Economic and Cultural Environment
Potential for impacts
on waterfront
recreational or
commercial facilities.
No difference – both alternatives will protect
recreation and commercial facilities.
No difference – both alternatives
will protect recreation and
commercial facilities.
Opportunity for
enhancement of
waterfront recreational
or commercial
facilities/ amenities.
Both alternatives will protect recreation and
commercial facilities. The north-east facing
entrance layout will provide the best protection
against the smaller more frequent waves.
Both alternatives will protect
recreation and commercial
facilities. The north-west facing
entrance layout will provide the
best protection against the larger
although less frequent waves.
During consultation, boaters
expressed a slight preference for
this alternative.
Potential for impact on
public safety.
No difference – both alternatives will protect
recreation and commercial facilities.
No difference – both options will
protect recreation and commercial
facilities.
Potential to impact
cultural heritage
(archaeological
resources or built
heritage and cultural
landscapes) and/or
treaty rights.
No difference – neither option will impact
cultural heritage.
No difference – neither option will
impact cultural heritage.
Hamilton West Harbour Shoreline and Breakwater Class Environmental Assessment: Environmental Study Report
April 17, 2013
Dillon Consulting Limited Page 85
Evaluation Criteria Option 1: North-East Facing Entrance Option 2: North-West Facing
Entrance
Impact on
Navigability
No difference – both options provide protection
during storms and require navigable waters
protection act approval.
No difference – both options
provide protection during storms
and require navigable waters
protection act approval.
Socio-Economic and
Cultural Environment
Summary
Both options with protect the waterfront amenities. A slight preference for the
north-west facing entrance was expressed by representatives of some of the boating
organizations.
Technical
Structural integrity No difference – both are suitable for site
conditions.
No difference – both are suitable
for site conditions.
Level of protection
provided.
No difference – both are suitable for site
conditions.
No difference – both are suitable
for site conditions.
Design life/
Maintenance
requirements.
No difference – both have a life of 20-40 years
and require the same maintenance.
No difference – both have a life of
20-40 years and require the same
maintenance
Potential for
contamination issues
No difference – both are in the same location
and contamination issues are not anticipated.
No difference – both are in the
same location and contamination
issues are not anticipated.
Flexibility No difference – both provide similar flexibility. No difference – both provide
similar flexibility.
Potential impacts on
utilities
No difference – neither option is likely to
impact utilities.
No difference – neither option is
likely to impact utilities.
Constructability No difference – both are straightforward to
construct.
No difference – both are
straightforward to construct.
Technical Summary There is no difference between the layout options from a technical perspective.
Cost
Relative cost
differences.
No difference – cost is the same for both
options.
No difference – cost is the same for
both options.