Specifications include, but are not limited to: The Vermont Natural Resources Council (VNRC) is requesting proposals from engineers licensed to practice in the State of Vermont for the development of a comprehensive geomorphological assessment and detailed (100%) design plan for the removal of Cross Brothers Dam on the Dog River, located in Northfield, Vermont. VNRC is acting as Project Manager on behalf of the Town of Northfield, which owns the dam and has a public safety interest in the dam. The goal of the project is to finalize the design for the removal of the dam and fully investigate the impact of the removal design on water quality, habitat, and flooding. The consultant will work under the direction of VNRC with support from the Town of Northfield (landowner), and other stakeholders. Funding for this project is a collaboration of partners including Vermont Emergency Management via the FEMA Hazard Mitigation Grant Program, Vermont Natural Resources Council, and The Nature Conservancy. A. Final Engineering Design, Benefits Cost Analysis (BCA), Environmental Review (EHP) and dam removal survey layout Review all existing information and complete required for final dam removal design, which is defined broadly as: This project shall include advancing the existing feasibility study and preliminary design (VNRC has CAD files available to selected contractor) and using their own data collection, analysis, and design expertise to finalize the design (stages 60%. 90%, 100%), and conduct a FEMA - Benefit Cost Analysis (BCA). Once the final design and BCA is complete. The consultant will work with the project team to prepare and facilitate the environmental review (From FEMA Agreement – “Review: The non-Federal entities and FEMA will conduct a review of the final project design to ensure EHP compliance”). Following support and submittal of permit applications the consultant will conduct dam removal survey layout to prepare the project for the implementation phase of dam removal. This phase should include the following tasks. 1. Utilize existing survey info and supporting CAD files to proceed with this stage of the project and complete additional survey and probing as described below if necessary. 2. Survey and characterize the longitudinal profile of the channel’s thalweg and cross sections for the affected upstream and downstream reaches. The longitudinal profile should extend upstream past the end of the impoundment and downstream to a distance of 20-30x the bankfull width. 3. Document the extent and approximate dimensions of the wedges of deposited sediment upstream of the dam. Include an updated estimate of sediment volume for the dam, and outline sediment management alternatives for the dam removal. If needed, implement a sediment sampling protocol to characterize sediment quality and identify potential contaminants. 4. Model changes in flow depth, floodplain inundation, channel patterns, and stream velocities that are likely to occur following dam removal. 5. Determine, using existing information, additional field investigations, and modeling results, the effect dam removal will have on the stability of any upstream or downstream infrastructure.
