March 13, 2007
To:
Kelly Pender Town of Perth
Anne Bendig Ministry of Natural Resources, Kemptville District
Al Robertson Transport Canada, Prescott
Georgina Williston Fisheries and Oceans Canada, Prescott
Kerry McGonegal Rideau Canal - Parks Canada
Bruce Hawkins Ministry of the Environment. SE Region, Kingston
David Taylor Friends of the Tay River
Bob Argue EcoPenth
From: Bruce A. Reid, P.Eng.
Director, Watershed Science and Engineering Services
Subject: Haggart Island Dam Reconstruction
Final Design Report Distribution
This distribution of the above-noted report, prepared on behalf of the RVCA and the Town of Perth by Ainley Group Ltd. and their sub-consultants, marks the completion of the functional design phase of a proposed project to re-construct two fixed weir structures on the Tay River in the Town of Perth.
The report sets out the rationale for a decision by the RVCA and the Town of Perth to proceed with a project to reconstruct the weirs and provides a cost estimate for doing so, following the recommended design and general arrangement as depicted in the drawings.
The RVCA and the Town are currently proposing to allocate funds in their respective 2007 budgets to cover 50% of the estimated re-construction cost, and the RVCA will soon be applying for matching funding from the 2007-08 round of the Conservation Authorities' Water and Erosion Control Infrastructure (WECI) Fund, administered by the Ministry of Natural Resources.
Drawing on the contents of this report, a "Project Plan" will be prepared and placed on the public record for review and comment prior to initiating construction, if and when the required funding is in place, to satisfy RVCA's obligations under the Environmental Assessment Act.
Formal requests for regulatory approvals under the Lakes and Rivers Improvement Act and the Navigable Waters Protection Act will also be 'Made after the required funding has been secured. In the meantime, the regulatory agencies are invited to review and comment on the enclosed report. Any feedback we receive will be taken into consideration during the preparation of formal applications for approval and the final tender documents (construction drawings and specifications).
We would like to take this opportunity to acknowledge the valuable input that you and your organization have made to the planning ad design of the project so far. Your assistance is appreciated. Thank you in advance for any additional comments and suggestions that you may have at this time.
Please don't hesitate to contact the undersigned at your convenience if you have any questions. ,
Best Regards,
(signed)
Bruce A. Reid, P.Eng.
Director, Watershed Science
and Engineering Services
(613) 692-3571 ext. 1103
cc: John McEwan, P.Eng.
Ainley Group Ltd.
HAGGART ISLAND DAMS
RECONSTRUCTION
Final Design Report
February 2007
Prepared for:
Rideau Valley Conservation Authority
Prepared by:
Ainley Group
In Association with:
EcoTec Environmental Consultants Inc.
Commonwealth Historic Resource Management Ltd.
J.F. Sabourin and Associates Inc.
Harmer Podolak Engineering Consultants Inc.
Haggart Island Dams Rideau Valley Conservation Authority
_________________________________________________
Table of Contents
|
|
Page |
1.0 |
Introduction |
1 |
2.0 |
Background Information |
1 |
|
2.1 Fisheries and Wildlife Habitat- Aquatic Environment |
2 |
|
2.2 Landscape Aesthetics, Park Planning and Heritage Conservation |
2 |
|
2.3 Water Level and Stream Flow Control - Hydraulics |
3 |
|
2.4 Structural Integrity of the Dams and Rainbow Bridge |
3 |
|
2.5 Public Safety |
3 |
3.0 |
Public Consultation |
4 |
|
3.1 Flow Related Issues |
4 |
|
3.2 Design Related Issues |
4 |
|
3.3 Nature and Historical Issues |
5 |
|
3.4 Safety Issues |
5 |
|
3.5 Recreational Issues |
5 |
4.0 |
Existing Conditions |
5 |
|
4.1 Aquatic Environment |
5 |
|
4.1.1 Fisheries Survey |
5 |
|
4.1.2 Existing Fisheries and Aquatic Habitat |
6 |
|
4.1.3 Habitat Characteristics |
6 |
|
4.1.4 Areas of Concern |
7 |
|
4.2 Landscape and Architecture |
8 |
|
4.2.1 Landscape Aesthetics and Park Planning |
8 |
|
4.2.2 Heritage Conservation |
9 |
|
4.2.3 Historic Value and Interpretive Potential |
9 |
|
4.3 Hydraulics Analysis |
10 |
|
4.3.1 Natural Conditions |
10 |
|
4.3.2 Existing Conditions |
10 |
|
4.4 Structures |
11 |
|
4.4.1 Dam Structures |
11 |
|
4.4.2 Pedestrian Bridge |
11 |
|
4.5 Public Safety |
11 |
Ainley Group Final Design Report
Haggart Island Dams Rideau Valley Conservation Authority
Table of Contents (cont'd)
|
|
Page |
5.0 |
Analysis and Observations |
11 |
|
5.1 Aquatic Environment |
12 |
|
5.2 Landscape |
12 |
|
5.2.1 Landscape Aesthetics and Park Planning |
12 |
|
5.2.2 Heritage Conservation |
13 |
|
5.3 Hydraulics |
13 |
|
5.4 Structures |
13 |
|
5.4.1 Dams |
13 |
|
5.4.2 Pedestrian Bridge |
14 |
|
5.5 Public Safety |
14 |
6.0 |
Statement of Design Objectives |
14 |
|
6.1 Water Levels |
14 |
|
6.2 Flow Splitting-Haggart Island Dam and Tay Road Dam |
14 |
|
6.3 Environmental Factors |
15 |
|
6.4 Fish Migration |
15 |
|
6.5 Landscape and Architecture |
15 |
|
6.6 Public Safety |
15 |
7.0 |
Design Options |
16 |
|
7.1 Development of Design Options |
16 |
|
7.2 Assessment of Design Options |
16 |
|
7.3 Design Alternatives |
16 |
8.0 |
Public Consultation and Municipal Approval during The Feasibility Study
|
17 |
|
8.1 Public Consultation |
17 |
|
8.2 Municipal Approval of the Feasibility Study |
18 |
9.0 |
Development of the Detailed Design |
18 |
|
9.1 Geotechnical Investigation |
19 |
|
9.2 Additional Fisheries and Aquatic Habitat Assessment |
19 |
|
9.3 Hydraulic Analysis |
19 |
|
9.4 Preliminary Concrete Dam Design |
21 |
|
9.5 Preliminary Timber Crib Alternatives |
22 |
|
9.5.1 Alternative 1 - Timber Cribs Stay in Place |
22 |
|
9.5.2 Alternative 2 - Timber Cribs Encased |
22 |
|
9.5.3 Alternative 3 - Timber Cribs Removed |
22 |
|
9.6 Timber Crib Recommendations |
23 |
|
9.7 Functional Design of Fish Migration Options |
23 |
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9.7.1 Fish Ramp on the Tay River |
23 |
|
9.7.2 Fish Passageway on the Tay River |
25 |
|
9.7.3 Fish Migration Options on the Little Tay |
26 |
Haggart Island Dams Rideau Valley Conservation Authority
Table of Contents (con 'd)
|
9.8 Construction Cost Estimate 9.9 Outstanding Issues |
Page 27 27 |
10.0 |
Potential Environmental Effects and Mitigation Measures |
28 |
|
10.1 Removal of Woody Vegetation and Associated Wildlife |
|
|
Habitat, and Damage to Adjacent Vegetation |
28 |
|
10.2 Decreased Water Quality and Aquatic Habitat Quality |
|
|
in the Tay River |
28 |
|
10.3 Accidents and Malfunctions |
29 |
|
10.4 Compromised Human Health and Safety |
29 |
|
10.5 Disruption to Adjacent Residences, Traffic, Transitway |
|
|
Access and Pathway Users |
30 |
|
10.6 Improper Waste Management |
30 |
|
10.7 Disruption of Archaeological Resources |
30 |
|
10.8 Improved Water Supply Reliability |
31 |
11.0 |
Monitoring Activities |
31 |
12.0 |
Public Consultation and Municipal Approval Of the Detailed Design |
32 |
|
12.1 Friends of the Tay Watershed (FoTW) |
32 |
|
12.2 Department of Fisheries and Oceans (DFO) and |
|
|
Ministry of Natural Resources (MNR) |
32 |
|
12.3 Transport Canada |
33 |
|
12.4 Adjacent Properties |
34 |
Appendices
Appendix A:
Feasibility Study- Paper Ad and Questionnaire
Appendix B:
Feasibility Study- Hydraulic Analysis and Modeling Results
Appendix C:
J.F. Sabourin and Associates Inc. - Field Investigation Report
Appendix D:
Detailed Design - Hydraulic Analysis and Modeling Results
Appendix E:
Correspondence between RVCA & the property owner at 2 John Street
Haggart Island Dams Rideau Valley Conservation Authority
Haggart Island Dams Reconstruction
Final Design Report
1.0 Introduction
The Ainley Group (Ainley) has been studying the redesign of the Haggart Island Dams for some time. Ainley was originally retained in 2004 by the Rideau Valley Conservation Authority (RCVA) to prepare a Feasibility Study for the Rehabilitation of the Haggart Island Dams. The Ainley project team also included Commonwealth Historic Resource Management (CHRM), EcoTec Environmental (ET), Harmer Podolak Engineering Consultants (HP) and J.F. Sabourin and Associates (JFS). Subsequently in 2005, the Ainley team was retained to complete the Environmental Assessment process through the preparation of the design of the recommended option from the 2005 Feasibility Study, incorporating all known outstanding issues. In order to satisfy the Federal Environment Assessment requirements in a single document, this Final Design Report includes the key information from the 2005 Feasibility Study, and provides additional design information and updated construction cost estimates. This report also looks at the potential environmental effects associated with reconstructing the Haggart Island dams, as well as mitigation measures and suggested environmental monitoring activities.
2.0 Backqround Information
The Haggart Island Dams are located on the Tay River in the Town of Perth and were constructed in approximately 1971. These dams are comprised of two separate and independent dams - the Haggart Island Dam and the Tay Road Dam. The Haggart Island Dam is located on the south arm of the Tay River and the Tay Road Dam is located on the north arm. Figure 1 illustrates the locations of the dams; Photograph 1 and 2 are photographs of the Haggart Island Dam and the Tay Road Dam respectively.
Due to the deteriorating condition of these structures, the RVCA, in partnership with the Town of Perth (Perth), commissioned Ainley to undertake a Feasibility Study to address the following items:
Ø To identify and evaluate the range of options that were available for the repair or reconstruction of the two dams;
Ø To provide the technical information required allowing the RCVA and the Town of Perth to decide upon the preferred solution and to support efforts to secure funding for the final design and construction; and
Ø To satisfy the initial stages of the environmental assessment process regarding the selection of RCVA Program Options related to the structures.
As noted above, although the primary focus for the Ainley team was to determine the required alternative for the water control structures (dams), there was also the inherent "environmental process" that had to be followed - to compile, present and assess the information to determine the preferred alternative, including public consultation. In particular, the information relating specifically to the following items was reviewed in detail:
Ø Fish habitat;
Ø Flood Mapping (HEC2 modeling);
Ø Historical flow data;
Ø Condition of the dams;
Ø Historical significance of the dams and their relation to the area;
Ø Recreational opportunities for the area; and
Ø Previous public consultation records.
In this regard, all relevant material from information sources such as RVCA, Town of Perth, historical records, community groups and related websites, was gathered to provide accurate and acceptable design options.
2.1 Fisheries and Wildlife Habitat - Aquatic Environment
Field and background data has been compiled in order to establish the existing conditions of the study area. All background information regarding the natural features of the study area, including fisheries, aquatic habitat, significant riparian vegetation or wildlife species, area sensitivities, and management strategies for these natural resources has been reviewed in order to establish all potential environmental sensitivities, issues and/or commitments that may influence this project. More specifically, the fish and wildlife information has been obtained from the RVCA, Ministry of Natural Resources (MNR) fisheries and wildlife data, Royal Ontario Museum (ROM) fisheries data, MNR Natural Resource Values and Information System (NRVIS), and any other published or unpublished sources.
Initially our team conducted a field survey of the study area in order to acquire up-to-date information on the late fall/early winter fisheries resources, aquatic habitat, water quality, terrestrial vegetation and resident wildlife. The intent was to set baseline conditions with respect to other unrelated development activities which may affect the environment without this project being considered.
Subsequently, our team conducted three separate field surveys of the study area in the spring of 2005 in order to acquire some up-to-date information on the spring fisheries resources. The intent was to compliment field data collected from the fall of 2003. The fisheries and aquatic habitat inventory was conducted 200m upstream and downstream of the Haggart Island dams and included the following:
Ø assessment of existing fish communities using various fish collection techniques (fish were captured using an electrofisher and gill nets (max. 30 min duration to prevent mortalities);
Ø visual night-time survey to determine whether walleye are using the areas below the dam for spawning activities;
Ø general water quality parameters including dissolved oxygen, temperature, pH, water colour, and electrical conductivity;
Ø critical habitat areas (e.g. potential spawning areas, foraging areas, deepwater holding habitat, large woody debris) and
Ø potential habitat compensation or enhancement opportunities.
The first spring field survey was carried out at night in order to assess the presence of spring migratory walleye. The second survey included an electro fishing survey of the study area. The third survey included a daytime gill netting survey upstream of the dam.
A photographic record was kept for the study area showing critical habitat, areas of potential compensation, and representative/rare fish species.
Following the collection of field data, an analysis of the potential effects of the preferred repair or replacement concept was examined. This included loss of spawning, nursery or foraging habitat for resident and migratory fisheries, deterioration of water quality, loss of riparian and terrestrial vegetation, and displacement of wildlife habitat. Generally the potential effects examined were within the immediate study area, however, consideration was also given to downstream or upstream effects.
2.2 Landscape Aesthetics, Park Planning and Heritage Conservation
The dams were integral to the operation of Haggart's Mill in the early 1800's and remain today as physical remnants of Perth's industrial and economic development. Once again, they have the potential to play a vital role within this community's contemporary landscape. As well, they provide an opportunity to be the catalyst in developing an interpretive pathway system in and around Perth that would benefit visitors and local residents alike.
The design and planning work strive to achieve the sensitive integration of conservation needs with contemporary usage, life safety, and code requirements, as well as with the improvement of a property's functional and economic performance.
2.3 Water Level and Stream Flow Control - Hydraulics
To initially address the effects/impacts on water levels and flow distribution around the Haggart Island when replacing either dam (or both) or incorporating additional water level control devices, the previously developed HEC-2 model of the Tay River was used. In doing so, the existing HEC-2 model data was verified and updated to ensure that sufficient information was available to properly simulate the current conditions. Since the previous HEC-2 model (circa 1981) was only done for the estimated 1:100-year flows of 150 m /s, the flow was re-evaluated based on several lower return peak flows to better assess the impacts of any proposed changes to the dams.
Through the hydraulic analysis, issues regarding water level were addressed to determine whether or not the dams were required in controlling the water level. With the analysis results under various conditions/flows, we were able to develop a summary statement of the foregoing points outlining the pros and cons of each option (with and without the dams).
Additionally, both water level control and stream flow control were considered simultaneously to arrive at the appropriate assessment. In determining the stream flow control requirements, several points were addressed such as:
Ø Expectations of the community regarding the apportionment of both present and future flows;
Ø Requirements of the stakeholders such as RVCA, MNR and the Town of Perth with respect to flows;
Ø D Conservation of the historical aspect of the dams and the area in general; Impacts on fish habitat, migration and spawning; and
Ø Development of a summary statement of the foregoing points.
2.4 Structural Integrity of the Dams and Rainbow Bridge
Initially, the existing condition report for the structures was reviewed and updated as required based on a field review to confirm the recommendations of the report. The field inspection consisted of a review (visual inspection) by a senior structural engineer to verify the existing conditions of both dams but did not include in-water inspection. Additionally, the Rainbow Bridge was only briefly reviewed to determine whether it creates potential hazards for users.
2.5 Public Safety
Throughout the research and design stages of the feasibility study, public safety was a prime concern. More specifically, safety issues were assessed in developing landscaping features and pathway planning. Although not limited to this, the main concern was the safety of the public with respect to the Rainbow Bridge, as well as the dams and recreational activities in and around the water.
12.0 Consultation with Regulatory Aqencies, Neiqhborinq Landowners and Friends of the Tay Watershed
During the preparation of this final design report, RVCA personnel met with representatives of agencies that are in a position to exercise regulatory control over the reconstruction c dams, and owners of lands immediately adjacent to the structures. The purpose of t meetings was to ensure that issues of concern to regulatory agencies and adjacent landowners would be identified and that measures to address those concerns would be provided in the design, and accounted in the cost estimates. A meeting with the members of the Friends c Tay Watershed was also held to inform them of the status of the design work, and to seek input.
These consultations were carried out in the summer of 2006 and are documented in minutes that are retained on file at the Conservation Authority. They are summarized here as follow
12.1 Friends of the Tay Watershed (FoTW)
Personnel of the RVCA met with the Friends of the Tay Watershed (FoTW) on June 7, 2006 at the Perth City Hall. RVCA staff provided a brief overview of the design drawings for the structures and invited any comments that the group may have.
FoTW agreed with the goal of achieving a natural flow split between the two channels of 20 % to the Little Tay with 80 % to the Tay River. There was also a discussion regarding the need for "stop logs" in the new design. It was noted that 1;100-year flood elevations would be slightly reduced from previous estimates, with the proposed dam configuration, according to the JF Sabourin computations, so it is not expected that additional flow capacity through a stop log section would be needed. The "stop logs" have not been used in the past. There is significant concern as to who would be responsible for the addition/removal of the logs and how the various implications to the competing concerns for the upstream and downstream impacts would be determined. The incorrect operation of the "stop log" system could alter the resulting flow split, which would impact adjacent properties. Therefore, the design team considers the preferred solution to be the construction of permanent structures that would provide the recommended flow split.
FoTW is interested in promoting a micro-hydro element of this project. Due to limited capital funds, RVCA has indicated its willingness to amend the design of the dam reconstruction to accommodate a micro-hydro installation, if a party, who is willing to finance the initial investment in micro-hydro equipment, is identified.
There was some concern regarding the height of the existing abutments. Abutment designs will be selected such that the overall height of the proposed embankments will be minimized.
As part of an overall recreation plan, FoTW encourages the development of a well-marked portage route for canoeists. This would be undertaken as a separate project.