Full text



In early 2010, the Town of Ajax was provided with updated floodplain mapping for Carruthers Creek, based on a Regional Storm event (i.e., Hurricane Hazel), prepared by the Toronto and Region Conservation Authority (TRCA) and R.J. Burnside & Associates Limited.

The updated mapping redefines the depth and extent of flood waters for the creek, the effects of which are most pronounced in the lower reaches of the watershed. Notably, a “Spill Area” has now been identified extending from the main Carruthers Creek channel upstream of Shoal Point Road bridge through a significant portion of the Pickering Beach neighbourhood south of Seabreeze Road to Lake Ontario. For the purpose of this proposal, the “Flood Remediation Area”, shall be bounded by Audley Road to the east, Bayly Street to the north, Pickering Beach Road to the west and Lake Ontario to the south. The “Watershed Area” for this study is the entire Carruthers Creek watershed as delineated on Figure 1.


The Carruthers Creek watershed extends north from Lake Ontario for approximately 17 km and has a drainage area of approximately 3650 ha. The watershed is elongated in a north-south direction with a length to width ratio of approximately 8 to 1. The upper reach is agricultural and the lower reaches are presently developed with a mixture of residential, commercial and industrial.

The Toronto Region Conservation Authority (TRCA) has recently undertaken a comprehensive process to revise flood plain mapping along a number of creek systems across its jurisdiction. The updated Carruthers Creek flood plain mapping is a component of TRCA’s ongoing work to identify and protect flood vulnerable areas based on updated mapping and modeling techniques governed by the Ministry of Natural Resources.

This project is an Environmental Assessment (EA) which shall:

i) review and update the hydrology for the watershed as required;

ii) identify potential risks to the hydrology for the watershed including approved urban areas and the long term potential for urbanization in the Carruthers Headwaters; iii) identify options to mitigate the downstream flood risks based on existing, approved

and potential urban developments within the watershed;

iv) and identify solution(s) to mitigate/remediate the risk of flooding within the watershed, and in particular, the “Flood Remediation Area”.


The following documents shall be provided to the successful Proponent upon selection. However, during the Proposal period, these documents are available for viewing at the Town’s Planning and Development offices or the TRCA offices, on request:

• R.J. Burnside & Associates Limited “Toronto Region and Conservation Authority, Summary Report for Digital Floodplain Mapping Carruthers Creek Spill Analysis”, December, 2009; (available at TRCA)


• R.J. Burnside & Associates Limited “Summary Report for Digital Floodplain Mapping Carruthers Creek, and Millers Creek Watersheds, Toronto Region and Conservation Authority”, August, 2007; (available at TRCA)

• Philips Engineering, “Carruthers Creek Hydrology Update for Toronto and Region Conservation Authority”, March, 2007; (available at TRCA)

• Carruthers Creek Master Drainage Plan September 1991 by Totten Sims Hubicki Associates

• Carruthers Creek Stormwater Management Strategy June1994 by Totten Sims Hubicki Associates

• Carruthers Creek Stormwater Management Strategy Synopsis Report June1995 by Totten Sims Hubicki Associates

• Carruthers Creek Stormwater Management Strategy June 1999 Addendum 1 by Totten Sims Hubicki Associates

• Topographic data;

• Town of Ajax Official Plan (see;

• Draft Amendment No. 38 to the Town of Ajax Official Plan (revised Environment policies);

• Town of Ajax Staff Report for General Government Committee dated April 22, 2010 (see

• City of Pickering Official Plan (see;

• Durham Regional Official Plan (see also;

• Proposed Amendment 128 to the Durham Regional Official Plan, and the draft Decision of the Ministry of Municipal Affairs and Housing dated March 12, 2010 (see also;

• TRCA Flood Plain Mapping and HEC-RAS Computer Model; (available at TRCA)

• Watershed Plan for the Duffins and Carruthers Creeks and State of the Watershed Report (see;

• Maps of significant environmental features can be found in the Town’s Official Plan (see;



The Town has classified this undertaking as a Schedule “C” initiative under the Class EA process as outlined in Municipal Class Environmental Assessment document prepared by the Municipal Engineers Association (MEA) dated October, 2000 as amended in 2007.

Schedule ‘C’ projects include all phases and require, at a minimum, two mandatory points of contact with the public and relevant review agencies.

The Proponent shall thoroughly review the project and confirm in its Proposal that the EA classification is correct. If the Proponent is of the opinion that the project should be classified differently, then this shall form part of the bid document, and brought to the attention of the Town’s Project Manager accordingly.



The Project Management Team, consisting of the Proponent’s Project Manager (or their designated alternates), will lead the project, with the support of the Town’s Project Manager, and the TRCA’s Project Manager. The Proponent’s Project Manager will guide the tasks and functions of any other affected groups.

The Proponent’s Project Manager will make all day-to-day decisions, address requests for information, and provide direction to project staff.

The Town’s Project Manager and the TRCA’s Project Manager are to be:

• kept informed of progress regularly. It is expected that there will be monthly progress reports for the duration of the project;

• copied on all correspondence;

• advised of significant problems/issues, options considered and solutions adopted; • consulted regarding deviations from standards, specifications and procedures prior

to their implementation;

• involved in any meetings with stakeholders, if available; • advised of any potentially controversial issues; and • consulted prior to changes of the project schedule.

The successful Proponent will be responsible for co-coordinating all activities and submittals with this Project Management Team. The successful Proponent should expect that any design aspect that affects an agency would have to be reviewed, commented upon and/or approved by that entity prior to its acceptance by the Town.


The successful Proponent will be responsible for guiding the public involvement in accordance with Schedule “C” of the Municipal Class Environmental Assessment Act. The public at large will be provided opportunities to offer input at various stages. Most contact will be through direct interaction with affected property owners and other interested parties.


Public Information Centres (PICs) are required to offer stakeholders an opportunity to comment on the Alternative Solutions (Phase 2 – PIC No. 1) and the Design Concepts for the Preferred Solution (Phase 3 - PIC No. 2). Other approaches, such as newsletters, web site, etc., should also be used to inform the public at the major milestones of the project. The successful Proponent will be responsible for arranging the advertisement of public notices, circulation to interested parties, and coordinating public meetings. The successful Proponent will, upon direction from the Town of Ajax and the TRCA: prepare the Public Notices and direct the above noted Public Information Centres; make presentations to Ajax Council and Committees (including two progress meetings at General Government Committee, two update meetings before the Town’s Environmental Advisory Committee, one public meeting to present the completed study at Community Affairs and Planning Committee, and one presentation before Council); prepare all the necessary presentation and circulation documents; address comments and respond to questions from interested stakeholders.

Although the successful Proponent will be expected to lead the public involvement activities, Town and TRCA staff will play an active role in the program and are committed to participating at all public forums. In many instances, the Town and successful Proponent will work together to do such tasks as:

• facilitate public forums;

• maintain the project contact list;

• prepare notices, newsletters and brochures for publication; and respond to inquiries 4.0 SCOPE OF WORK

The scope of work for this project will be to carry out a Class EA planning and design process along with completion of the preliminary detailed design documents for implementation of the recommendations.

The Proponent will be responsible for all aspects of work. Proposals submitted in response to this RFP shall describe the work required to provide these Services, and may be rejected if the requirements are not addressed to the Town’s satisfaction.

The tasks described in the following subsections may not be inclusive and are not listed in any particular order. Proponents may suggest additional items that they feel would benefit the project. Proponents are also encouraged to identify and make recommendations about the order, efficiency and appropriateness of the tasks listed below. Measures that would make the most effective use of the available resources and/or would expedite completion of the Services should also be noted.


The successful Proponent shall provide General Services to effectively initiate the project, manage the project, involve the public and to obtain field data. The successful Proponent will be required to assume responsibility for all services offered in its Proposal regardless of whether or not the Proponent performs them in-house. The Proponent will be fully responsible for adherence by sub-consultants to all provisions of the contract. The successful Proponent will


be the sole point of contact for contractual matters, including payment of any or all charges resulting from the contract.


The successful Proponent shall meet with the Town’s Project Manager, TRCA’s Project Manager and other Town staff at the outset of the assignment to obtain relevant background information and confirm the extent of services, work program and project schedule outlined in the Proposal.

Following the meeting, the successful Proponent shall submit an updated work program and project schedule to the Town’s Project Manager within two weeks for approval, reflecting any changes discussed. Assemble a project contact list in consultation with Town’s Project Manager, and notify review agencies and other stakeholders on the list of project initiation by letter or other appropriate method of communication (i.e. newsletter, etc.).


The successful Proponent shall arrange, attend, prepare and issue minutes for, and provide written responses to questions raised at all meetings with Town staff, review agencies and other stakeholders. The Proponent shall issue correspondence resulting from the meeting (minutes, responses, etc.) within five (5) business days.

The successful Proponent shall prepare reports, submit plans, specifications, and applications to the Town, affected review agencies, and other stakeholders to secure required approvals, permits or clearances. This may require the Proponent to prepare draft and final agreements, attend meetings and pay required fees (to be recovered through disbursements). Where appropriate, the Proponent shall obtain and integrate comments on documents produced. The successful Proponent shall prepare and submit a monthly Progress Report including work completed that month, anticipated work for the following month, issues and concerns, and any potential changes to scope, budget or schedule.


The successful Proponent shall conduct the external consultation program, including but not restricted to:

• discussions and correspondence with all stakeholders;

• meetings, negotiations, external presentations (including presentation material and “dry runs”), and associated minutes/correspondence;

• preparation of public notices, newsletters (budget for a minimum of three newsletter updates of project status for circulation to the Flood Remediation Area residents) and brochures in the Town’s format;

• preparation, operation and follow-up for Public Information Centres and Community Meeting, including displays, venue booking and payment (to be recovered through disbursements), “dry runs”, set-up, attendance, minutes/summary, and responses to comments; and


• satisfaction of Municipal Freedom of Information and Protection of Privacy Act requirements for the above.

The external consultation elements are subject to pre-approval and participation by the Town. The successful Proponent shall plan and budget for a minimum of two (2) Public Information Centre and one (1) Community Meeting in their Proposals. The Proponent shall produce all display material (including drawings) for these meetings in appropriate paper and digital (pdf) formats in advance for the Town’s review and approval. The Proponent shall create and lead a power point presentation and provide paper overview material for the meetings. The Proponent shall provide the final digital material to the Town the next business day following the Public Information Centre or Community Meeting. The Town may post this material to its web site. The successful Proponent shall also plan and budget for Committee of Council (3), Council (1) and Town’s Environmental Advisory Committee meetings (2). The Proponent shall prepare a presentation for each of the meetings describing the proposed design solutions, the impact of the project (including any major public concern) and the Environmental Study Report (ESR). Committee meetings are typically held at night starting at 7:00 PM.


The successful Proponent shall carry out all necessary field work not provided by the Town, to identify flood management measures in the most cost-effective way. This will include any additional topographical survey requirements, water crossings, storm sewer sizes and inverts. Arrange for “Permission to Enter” through the Town’s Project Manager prior to commencing fieldwork on public or private property not owned by the Town. Geotechnical information may be required to evaluate the feasibility of some of the proposed solutions.


Identify and verify factors causing the increased flood vulnerability in the lower Carruthers Creek watershed. Identify opportunities to reduce and mitigate the flood risk in the this area, specifically as it relates to flood vulnerable properties, infrastructure needs and improvements, public safety, required remedial works and policy approaches and best practices.

Phase 1 – Identification of Problems or Opportunities

Compile an inventory of the natural, social, planning and economic environments within the watershed from the background data, and from field and secondary source investigations, and produce relevant mapping of environmental constraints. Fieldwork shall be conducted during the appropriate season(s) and be of sufficient scope to satisfy requirements for necessary approvals

Phase 2 – Selection of Preferred Solution

Select the preferred solution to the identified problems and/or opportunities (Phase 2 – Selection of Preferred Solution). In completing this task, the Consultant shall develop and evaluate a range of alternatives, including but not limited to:


Do nothing;

• Physical modifications and improvements to existing facilities, structures and stream channels, including those within or near the Flood Remediation Area; • New facilities, structures and modifications for managing the Regional Storm


• Recommendations that responds to potential urbanization within the Carruthers Creek Headwaters and the potential impacts to downstream; and

• Operational or structural improvements.

Each alternative will be evaluated based on a series of criteria to be developed jointly by the Consultant, TRCA and the Town, falling into the following general categories:

• Social environment (i.e. land use, noise, heritage, agricultural land, etc.)

• Natural environment (i.e. woodlots, creeks, wetlands, wildlife, birds, vegetation, air quality, etc.)

• Technical (i.e. hydrology, hydraulics, structural adequacy, etc.) • Cost (i.e. capital, operating, maintenance, etc.)

Prepare a Need and Justification Report summarizing the findings of Phases 1 and 2. The Consultant shall confirm that the appropriate Municipal Class EA schedule is being followed for the project in the Report.

Phase 3 – Select the preferred design concept for the preferred solution.

In completing this task, the Consultant shall identify and evaluate a range of alternatives (Selection of Preferred Design Concept).

Prepare the preliminary design for the preferred design concept (Phase 3 – Selection of Preferred Design Concept and supply a cost estimate). The section below further details the tasks required for this activity.

Phase 4 – Prepare an ESR to document the Class EA planning and design process completed (Preparation of ESR).

Documentation shall be in accordance with Chapter A.4.2 of the Municipal Class EA and shall include the following items:

• A summary of environmental concerns and commitments in tabular form.

• The final preliminary design drawings, cost estimates, and the completed Project Criteria Sheet, as described below.


• A technical appendix containing all background reports prepared during the study and the details of the public involvement program, including all comments received.

• Respond to inquiries about the ESR, including any appeal requests. 4.7 PRELIMINARY SOLUTION(S)

The Proponent shall prepare solutions for improvements within the watershed, including preliminary design solutions for the Flood Remediation Area. The preliminary design phase for the Flood Remediation Area will determine the type of flood management solution(s) required, approximate limits of construction, criteria, property acquisition requirements, cost, items quantities, specifications and the need for utility relocations.

The design will provide sufficient information to enable property acquisition, utility relocation, tender for construction and permit applications. Cost estimates shall also be produced by the Consultant for budgeting purposes.

4.8 TASKS:

4.8.1 Carruthers Creek “Watershed” Hydrology Update

a. Review Philips Engineering, “Carruthers Creek Hydrology Update for Toronto and Region Conservation Authority”, March 2007

b. Assemble an inventory of watershed characteristics, such as stormwater management controls, flow gauge and rain gauge locations, existing and future land uses, topographic data, and soil information.

c. Update the TRCA’s Visual Otthymo Hydrologic model for the Carruthers Creek Watershed. Verify the model reflects the current land use ((Existing Official Plans(OPs) (based on the existing Durham of Region, City of Pickering and Town of Ajax Official Plans), subcatchment boundaries, reach network and all constructed and planned stormwater management facilities.

d. Perform calibration and validation of the Existing Official Plans (OPs) Condition model for water quantity using meteorological and flow data. A minimum of three (3) storm events for a period of 2007 through 2009 should be selected for calibration and validation. Data from multiple meteorological stations within the Carruthers Creek watershed and adjacent areas should be applied in a spatially distributed manner for both calibration and validation. Consultants should describe in their proposal the methodologies that will be considered for distributed application of meteorological data. Meteorological and streamflow data for calibration and validation are available from the TRCA and Meteorological Service of Canada, which will be provided by the TRCA. Figure 1 shows the location of the rain gauges and stream flow stations.

Calibration should be achieved by adjusting appropriate modeling parameters within accepted ranges conforming to typical modeling practices. The primary


focus of calibration should be to match simulated peak flows and overall hydrograph volumes to observed flows for the selected events

Calibration and validation should include comparisons of simulated and observed peak flow rates and volumes for all selected events. As a minimum, a graphical comparison of simulated and observed hydrographs for calibration and validation events should be provided as well as tabular comparisons of associated peak flows and volumes. The model calibration must be presented to and approved by Town of Ajax and TRCA prior to moving forward to the modeling of future land use scenarios.

e. Using the calibrated Existing OPs Condition model, confirm whether the 12 hour Atmospheric Environment Service (AES) design storm distribution is still appropriate for the watershed and if not, select a more appropriate distribution. Based on the calibrated Existing Condition model, the 2, 5, 10, 25, 50 and 100 year design flows will be estimated using the chosen storm distribution. The Regional flows will be estimated using the Regulatory storm event for the watershed (Hurricane Hazel). As per MNR procedures the routing effect of stormwater management facilities will be removed from the simulation of Regional flows.

f. Using the calibrated Existing OPs Condition model as a base, develop a hydrologic model for a Potential Future watershed development as set out in Durham Region’s adopted Regional Official Plan Amendment (ROPA) 128 (Growing Durham) which although has not received Provincial Approval, (i.e. the north east Pickering lands) land use scenarios for the watershed. The model will reflect future development, approved stormwater management plans including, as a minimum, additional stormwater management facilities. Where stormwater management facilities have not yet been sized for planned development areas, they will be sized in accordance with current quantity control criteria for the Carruthers Creek watershed. Stormwater management facilities must be depicted in the model in the same manner they are depicted in the Existing Condition model.

g. Run the Existing OPs Condition and Potential Future Condition models with the selected storm distribution as identified in Task e, and estimate the 2 to 100 year and the Regional flows. As per MNR procedures the routing effect of stormwater management facilities will be removed from the simulation of Regional flows. h. Present graphical and tabular comparisons for the Existing OPs, and Potential

Future Conditions at the points of interest.

4.8.2 Update SWM Flood Flow Criteria for Watershed Area

a. Present tabular comparisons of the Existing OPs, and Potential Future flows with Philips Engineering (2007) results.

b. Confirm if the SWM Flood Flow Criteria presented in the Phillips Engineering (2007) Hydrology Update are applicable. If not, provide updated SWM Flood Flow Criteria for the 2 to100 year design storm events.


c. Complete a Regional Storm flow analysis and determine if Regional SWM controls are required, If so, develop SWM Flood Flow criteria.

4.8.3 Assess impacts to TRCA Flood Line Mapping for Watershed Area

a. Review TRCA’s Flood Line Mapping and HEC-RAS model and assess if any of the existing map sheets need to be updated based on Task 4.8.2.

b. Update all applicable map sheets for the Watershed Area as a result of the findings and detail the costs separately.

4.8.4 Hydrology Update Report for Watershed Area

a. Prepare a standalone Hydrology Update Report to the Town of Ajax and TRCA documenting Tasks 4.8.1 to 4.8.3 with recommendations and policies for the Watershed Area.

4.8.5 Review Existing Hydraulic Model of Flood Remediation Area

a. Review and comment on R.J. Burnside & Associates Limited “Toronto Region and Conservation Authority, Summary Report for Digital Floodplain Mapping Carruthers Creek Spill Analysis”, December 2009.

b. Based on Task 4.8.3, if required, update existing hydraulic model and floodplain mapping for the Flood Remediation Area.

c. Characterize flood plain conditions within the Flood Remediation Area, including identification of structures within the flood plain, flood plain depth assessment, and identify flooding conditions (i.e. return period, Regional Event).

d. Identify policies and criteria to be applied to existing, new development and re-development in the Flood Remediation Area to help achieve TRCA flood plain management objectives.

4.8.6 Develop an Emergency Preparedness Plan for the Flood Remediation Area, Specific to Flooding Hazards

a. Identify emergency ingress/egress points into and out of the Flood Remediation Area.

b. Emergency assess points should conform to Ministry of Natural Resources Hazard Guidelines, specifically relating to flood hazards.

c. Identify/recommend roles and responsibilities within the Flood Remediation Area at the local and regional municipal level.


4.8.7 Identify and prepare a Flood Remediation and Capital Works Plan/Report with solution(s) to Mitigate Flooding in the Flood Remediation Area

a. Provide the necessary expertise for flood management and remediation to serve the best interests of the public, with due consideration for environmental concerns, capital cost(s) and operating efficiencies in accordance with current state of the art and acceptable engineering standards established by the Town and other applicable regulatory agencies;

b. Identify any adverse environmental impacts affecting private or public lands and recommend mitigation/remediation measures;

c. If necessary, identify any land or easement(s), permanent and working, necessary to implement the preferred flood management strategy. Conduct a title search to identify adjacent property owners. Assist in negotiations of permission to enter private lands for construction purposes, easements and purchases by providing technical information for use by the Town. Prepare Registered Plans (R-Plans) if required.

d. Provide proposed solution(s) for the Flood Remediation Area in accordance with all applicable design standards and criteria including but not limited to:

• Town of Ajax; • Region of Durham;

• Ministry of Natural Resources; • Ministry of Environment; and

• Toronto & Region Conservation Authority.

e. Prepare a geotechnical report if required in support of the proposed solutions. f. Prepare a tree inventory plan of trees that maybe required to be removed to

accommodate the preferred solution(s).

g. In coordination with Town and TRCA staff, develop a prioritized Implementation Plan with consideration to levels of mitigation/remediation versus cost for the proposed solutions.

h. Provide an allowance to undertake a Stage 2 archaeological assessment, if required, to determine the presence of prehistoric and historic archaeological resources, and any implications for design and/or construction of the preferred solution(s).

i. Review and update any environmental protection and mitigation measures outlined in the ESR requested by agencies and incorporate relevant provisions into the preliminary design.

j. Prepare a Preliminary Design and Report for the Flood Remediation Area, documenting key assumptions, information sources, and design parameters used in preparing the design, and the rationale for any deviations from the


recommended values. The proposed design features should include the following:

i. Stormwater and Flood design;

ii. Impacts, if any to existing sewer systems;

iii. Structures, flood diversion features and foundations; iv. Local drainage;

v. Proposed and existing topography; vi. Utilities;

vii. Property;

viii. Maintenance requirements; ix. Landscaping;

x. Construction issues, such as staging, new construction techniques, construction operations/sequence, contract sequencing, etc.;

xi. Environmental protection and mitigation measures; and

xii. Appendices containing supporting reports and other documentation (i.e. minutes and correspondence).

k. Prepare quantity and cost estimates for the Preliminary Design and Report. l. Identify innovative funding mechanisms from various levels of government to

implement the proposed solutions.

m. Identify the necessary approval process for all proposed flood mitigation/ remediation infrastructure. Provide traceable and defensible analysis/data. n. Circulate and secure approvals of the final Preliminary Design Report from the

Town and applicable regulatory agencies as required for approval.

o. Provide existing utility location information, identify relocation requirements and related costs. As part of this task, the Proponent shall update the drawings with the location of all affected utilities.

p. The Proponent shall provide presentations to Ajax Council, Committees of Council and Town’s Environmental Advisory Committee at key milestones in the project and will provide Council with notice and information on the public meetings. The Proponent shall guide the public involvement in the process and at Community Meetings and PICs in accordance with the Environmental Assessment Act and will be responsible for arranging the advertisement of public notices, circulation to interested parties, and meeting coordination.

q. Public Meetings. The Proponent will prepare the public notice, lead the presentations and direct public meetings along with providing all the necessary presentations and circulation documents and addressing any questions or concerns from the public.

r. The successful Proponent will prepare status reports and update the project schedules monthly.


s. Develop concept designs, showing principal features for the preferred flood remediation strategy.

t. Prepare a Hydraulic Assessment ensuring that the preferred solution(s) will have no adverse impacts to New Regional Flood lines in the area. TRCA modeling (HEC-RAS) and associated flood line mapping are to be used in the analysis. u. Assess internal drainage to ensure localized flooding within flood remediated

lands does not occur.

v. Prepare a Fluvial Assessment of Carruthers Creek by a qualified fluvial geomorphologist for the preferred solution(s).

w. If the preferred solution(s) strategy includes works associated with the Shoal Point Road bridge, the Consultant shall prepare a preliminary design of the Shoal Point Road bridge and approaches. The preliminary design shall include:

• Bridge Assessment Report, for the existing bridge, proposed bridge, pedestrian bridge and phasing for installation.

• Determine the appropriate sizing to accommodate terrestrial wildlife passage and fluvial geomorphic process.

• Prepare concept drawings and cost estimates for the preferred solution(s). • Conduct a cost-benefit analysis, including calculating costs incurred as a

result of flooding to the area, to determine the most cost-effective scenario for the Town and TRCA to consider.

4.8.8 Complete a Municipal Class Environmental Assessment as outlined in 4.6 for the Flood Remediation Area.





Related subjects :