Loading...
2023.03.23 Staff Report.pdf March 23 2023 Staff Report To: Conservation Commission From: Sarah LaValley RE: Staff Report, March 23 2023 Commission Meeting 5:30 PM – Continuation: Notice of Intent for storm drain repair; installation of new drainage pipe and catchbasins, slope stabilization, and walking path replacement. Work proposed within buffer zone to bank and riverfront (Mill River) Northampton DPW, Dryad’s Green, Parcel 31C-13 Application Overview: Work proposed is a storm drain reconstruction to repair an existing failed storm drain through installation of new drainage pipe and structures within the alignment. Deep sump catchbasins will replace four conditions to address water quality, and an existing slope is proposed to be stabilized and revegetated. All work will take place within city rights of way or within areas where a maintenance easement exists. The existing walking path along the Mill River bank is proposed to be restored when work is complete as an interlocking cellular concrete block. During larger storm events, erosion along the slope typically occurs, and stormwater discharge from the outfall includes visible suspended solids. DEP Comments: DEP Comments and applicant responses are attached. Staff has no concerns with the responses as provided. The Commission may wish to discuss DEP’s comments regarding the location of the outfall, but staff notes that the outfall location will not be located closer to bank than existing conditions, and that the outfall area may be limited by the path and slope. Consistency with the WPA and Northampton Wetlands Ordinance The application is submitted as a redevelopment project within a previously developed riverfront area. Pursuant to this section 310 CMR 10.15 (5), the Commission “may allow work to redevelop a previously developed riverfront area, provided the proposed work improves existing conditions. Redevelopment means replacement, rehabilitation or expansion of existing structures, improvement of existing roads, or reuse of degraded or previously developed areas.” The application includes a table (page 5) regarding the project’s compliance with riverfront area redevelopment performance standards as a riverfront redevelopment project. Staff has questions about compliance with the indicated performance standard (a), which requires that At a minimum, proposed work shall result in an improvement over existing conditions of the capacity of the riverfront area to protect the interests identified in M.G.L. c. 131 § 40. The Commission should discuss in detail how project; with a focus on the slope regrading, will result in an overall improvement. An improvement must also be demonstrated to allow work under the Ordinance for any work beyond the footprint of those areas that are already degraded. March 23 2023 Staff Report 2 Staff Recommendation, Conditions If the Commission finds that the work is improves existing conditions within the riverfront, an Order allowing the work may be issued, but additional conditions are suggested to protect the interests of the Act. Staff was not able to locate a detailed planting mix or planting plan for the slope in the application. Mowing is mentioned but not quantified. A detailed management plan for the slope area, include plantings and mowing schedule should be provided, including tree replacement if the Commission determines this to be necessary. An assessment of any plantings should be required prior to a certificate of compliance. Trees to be protected are noted on the plans, but removal and disposal of “brush, trees, dead/fallen trees and other debris’ is noted on the plans, and it is not clear if trees are being removed. A wooded slope with a varierty of over and understory plantings would provide habitat and other RFA value. The erosion and sedimentation control (ES) plan includes details for all typical ES measures, but the location and items to be utilized are not provided and are left to the contractor. A full ES plan should be provided prior to construction, this is critical due to the slope angle and existing erosion. Staff asked what ongoing O&M will be required for the project, and the applicant responded that the infrastructure will be maintained in accordance with the City of Northampton Stormwater Infrastructure Operation and Maintenance Plan (O&M Plan). This addresses the drainage work, but the Commission should discuss with the applicant whether any slope-specific O&M is necessary, and also whether any path maintenance will be needed in the future. Conditions were included as part of NHESP’s no-take decision, and must be included in the Order: State-listed Turtle Protection Plan. The applicant shall protect state-listed turtles during all work. The Applicant shall arrange for a qualified biologist to develop and implement a Wood Turtle Protection Plan. a. Prior to the start of work, said Protection Plan shall be submitted to the Division for review and written approval. The Protection Plan shall detail procedures for protecting state-listed turtles during construction. including visual sweeps, timing of site preparation, as well as potential use of a temporary turtle barrier. The Division is available for consultation on the development of the plan and for information regarding qualified biologists. A Commercial Scientific Collection Permit must also be obtained from the Division of Fisheries & Wildlife in order to handle state-listed turtles. b. If all work can be completed during the turtle inactive period (November 1 through March 31 of any year), active turtle sweeps may be avoided. 2. Stockpile/Storage of Soils. If such materials are stockpiled onsite, they must be fully enclosed by a turtle-proof barrier no later than May 15 and remain enclosed until July 1. If the materials are not enclosed by May 15, then they may not be moved, altered or added to until after September 30. This condition must be incorporated into the above-noted Turtle Protection Plan. 3. Native Plantings. Should a planting plan be proposed within the Project area, plantings, including seed mixes, shall be composed of species native to the County in accordance with ‘The Vascular Plants of Massachusetts: A County Checklist First Revision’ (Dow Cullina, M., B. Connolly, B. Sorrie, and P. Somers. 2011. MA NHESP DFW); available from State Library of Massachusetts at http://archives.lib.state.ma.us). The use of MESA-listed plants shall be avoided as part of any planting plan. March 23 2023 Staff Report 3 4. Erosion Controls. All erosion and sedimentation controls, and/or construction fencing shall be removed and properly disposed of after the project is completed and as soon exposed soils are stabilized. 5. Any mechanized maintenance of the stormwater feature (e.g., mowing of vegetation, etc.) shall occur during the turtle inactive season (November 1 through March 31 of any year). Hand tools may be used at any time of year. Said restriction shall be integrated into, and specified within, any operations and maintenance plan associated with the project.