REQUEST FOR PROPOSALS
CONSULTANT SERVICES
CABOT FLOOD STUDY: HYDRAULIC MODELING, ALTERNATIVES ANALYSIS AND CONCEPT DESIGN
TOWN OF CABOT, VERMONT
Date of Issue: June 5, 2024
Proposal Deadline: June 21, 2024
BACKGROUND
The Town of Cabot is seeking engineering consulting services to assist the town in identifying and selecting alternative measures that can be implemented to minimize the risk of future village flooding impacts from two tributaries to the Winooski River, one on the north end of the village (at junction of US Route 215 and South Walden Rd) and one in the center of the village (near Cabot Garage and Harry’s Hardware). See map for location. These tributaries course for several miles on steep slopes, and on July 10-11, 2023, they both overflowed their banks, causing erosion and flood damage to commercial and residential properties. Woody debris accumulation and high flows contributed to the flooding. The goal of this study is to conduct hydraulic modeling of these tributaries, develop alternative solutions to mitigate future flooding on each tributary, and develop a concept design for the preferred alternatives on each tributary.
SCOPE OF WORK AND DELIVERABLES
In general, the scope of this project will involve a close working relationship and good communication with The Cabot Flood Resiliency Task Force and the public. Deliverables are underlined.
1.0 Project Initiation and Data Collection
1.1 Participate in a project team meeting to review existing conditions, previous flood and erosion damage and project goals. During this meeting project roles will be discussed, and schedule and plans for project outreach will be determined. Past flood data will be provided by the Task Force to assist with model validation. Participate in a public meeting of the Task Force to inform community members of flood mitigation and resiliency efforts.
1.2 Conduct a stream channel walk of both tributaries to understand the upstream channels and watersheds. This will include an evaluation of upstream debris and identification of possible floodplain restoration and debris filter locations. These data are intended for use in evaluating the modeling and development of alternatives. Collect supplemental data to support hydrologic and hydraulic modeling. This includes measuring stream channel longitudinal profile and performing approximate field survey of up to 5 key wet channel cross sections to improve detail in the model. The survey will be completed by a licensed surveyor to collect high-precision survey data of the structures, adjacent stream channel, and nearby village infrastructure.
1.3 Prepare a GIS project map with collected field data from the stream walks and survey data around the culvert and bridge.
2.0 Hydrology Calculations and Hydraulic Modeling
2.1 Build hydrologic models of both tributaries’ watersheds to estimate flood flows at each structure. Validate flow estimates of flood events with reported flood levels and damages.
2.2 Conduct hydraulic modeling of the existing conditions for each tributary. The model will extend from approximately the downstream confluence with the Winooski River to 200-feet upstream of
each structure. 2-dimensional modeling will be used to allow for a detailed analysis of flow patterns through the village. The model will use survey data, approximate GPS data, and LiDAR data.
2.3 Perform model validation/calibration of both flows and flood elevations based on past flooding in the area to ensure the model generally represents existing flood patterns. It is assumed that the project team will provide past flooding information in terms of date, approximate magnitude of flood, and extent of flooding. The level of detail of the model validation will rely on the availability of past flood information. A table of estimated model accuracy will be made.
3.0 Alternatives Analysis and Reporting
3.1 Develop a list of alternatives and evaluate each with the hydraulic model. Potential alternatives include structure replacement, moving buildings, floodplain restoration, and large wood filters.
3.2 A project team meeting will then be held to discuss the modeled alternatives and choose a preferred alternative to move forward to concept design.
3.3 Draft a report detailing data collected during the stream walk, summarizing hydrologic and hydraulic modeling, and discussing alternatives analysis.
4.0 Concept Design
The top two preferred alternatives will be advanced to concept design. At this point we anticipate moving design forward for structures in the village that appear to be issues for flood mitigation.
4.1 Develop a concept design for the culvert on the southern tributary that is prone to clogging. The concept design will include a title sheet, existing and proposed conditions plans, longitudinal channel profile, and at least two stream cross-sections.
4.2 Develop a concept design for the bridge on the northern tributary if deemed appropriate.
PROJECT BUDGET
A sum not to exceed $66,000 has been budgeted for this project.
PROPOSAL FORMAT
Responses to this RFP should consist of the following:
A. A technical proposal consisting of:
1. A cover letter expressing the firm’s interest in working on this project and the strengths your team brings to the project, including identification of the principal individuals that will provide the requested services. Include each person’s area of responsibility as well as one-page resumes. Also include the same for any sub-consultants.
2. A description of the general approach to be taken toward completion of the project, an explanation of any variances to the proposed scope of work as outlined in the RFP, and any insights into the project gained as a result of developing the proposal.
3. A summary of estimated labor hours by task that clearly identifies the project team members and the number of hours performed by each team member by task.
4. A proposed schedule that indicates project milestones and overall time for completion.
5. Demonstration of success on similar projects, including a brief project description and a contact name and address for reference. Please provide a minimum of two references.
B. A cost proposal consisting of hours devoted to each task and estimated cost for each task.
CONTRACTING
A. Form of Contract
The agreement between the Town of Cabot and the Consultant shall take the form of a Not to Exceed, reimbursable contract. The Consultant shall provide services necessary to ensure the successful completion of the project as set forth in the Request for Proposals and the final Scope of Work. Changes, modifications or amendments in the terms and conditions of this Agreement shall be written and signed by the duly authorized representative of the Consultant and the Town of Cabot. Should it become necessary for the Consultant to procure additional sub-consultant services beyond those reflected in the Consultant’s proposal, this selection will be subject to approval by the Cabot Conservation Committee and the Town.
B. Payment
The Town will reimburse the Consultant in a timely manner following the submittal of monthly invoices and a brief progress report.
CONTRACT PERIOD
All work and deliverables on the project must be completed by November 1, 2024.
CONTRACTOR SELECTION
Proposals will be evaluated on the following criteria:
1. Qualifications of the firm and the personnel to be assigned to this project and prior experience. (20 points)
2. Demonstration of overall project understanding and insights into local conditions and potential issues. Clarity of the proposal, presentation quality/creativity, and thoroughness in addressing the scope of work. (40 points)
3. Creativity and effectiveness proposed public outreach process. (25 points)
4. Project cost and distribution of effort. (15 points)
Optional Interviews: Interviews with respondents to the RFP will be conducted if, in the opinion of the project selection committee, such interviews will aid in the selection of the firm most suited to
complete the project. Interviews may be conducted in person, by telephone, or by using other available technologies.
SUBMISSION REQUIREMENTS/RFP SCHEDULE
Proposals must be submitted electronically no later than 4:30 pm on June 21 to the following:
Gary Gulka:
contact@example.gov
Questions about the RFP should be directed to Gary Gulka, Cabot Flood Resiliency Task Force at:
Telephone:
+1 (555) 000-0000
E-mail:
contact@example.gov
The Town of Cabot reserves the right to reject any or all proposals received, to negotiate with any qualified source, or to cancel in part or in its entirety this RFP as in the best interests of the Town of Cabot. This solicitation in no way obligates the Town of Cabot to award a contract.
