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2019.10.24 Staff Report Conservation Commission Staff Report 1 October 24, 2019 To: Conservation Commission From: Sarah LaValley RE: Staff Report, October 24 Commission Meeting 5:30 PM – Request for Determination of Applicability (3) to determine if stormwater ‘designs with nature’ projects to retrofit existing stormwater systems to create bioretention areas, green infrastructure to reduce runoff, and subsurface detention are subject to the Wetlands Protection Act or Northampton Wetlands Ordinance. Applicant: Northampton Office of Planning and Sustainability. Locations: 120 Jackson Street, Map ID 24A-042, Jackson Street School 80 Locust Street, Map ID 23B-047, Smith Vocational 0 Old South Street, Map ID 31D-237, Municipal Parking Lot These applications are part of the City’s ‘Designs with Nature’ Municipal Vulnerability Program grant to design new green infrastructure retrofits on City-owned properties to mitigate runoff and treat stormwater discharge from existing historic systems where flooding, water quality and other issues are now present. Grant funding may become available in the future for construction of these projects. All work is designed to be an improvement over existing conditions. Application Overview: 120 Jackson Street (Jackson Street School): Existing drainage at the site directs runoff from parking areas, driveways and athletic areas to a closed system which eventually discharges to the Barrett Street Marsh. Work proposed includes creation of a bioretention basin with sediment forebay to create pretreatment, and a subsurface storage system to reduce peak flows during large storm events. Temporary disturbance of buffer zone is proposed during construction, but no new outfalls are proposed. If the Commission agrees that the work will not constitute an alteration, issue a negative determination by checking box 3, to indicate that the work is within the buffer zone, but will not create an alteration and does not require an NOI filing. Include standard conditions. 80 Locust Street (Smith Vocational): The existing stormwater system is a closed system that connects parking lot runoff with underground piping with manholes that discharge into a closed Locust Street system which discharges to Broughton’s Brook, a flashy system which sometimes floods and necessitates road closures. Work proposed includes conversion of existing lawn to bioretention basins to provide, storage, infiltration, and detention. Work proposed is contained with an existing stormwater system, and will not create any new outfalls. A negative determination can be issued; checking box 4, indicating that the work proposed is not within an area subject to protection. Note that wetland boundaries are not confirmed, 0 Old South Street: Existing drainage within the municipal parking lot flows to catchbasins that then discharge into the former Mill River channel with limited treatment. The channel is classified as a perennial stream. Work proposed is intended to increase treatment and reduce flow volumes through installation of a porous filter to replace existing concrete islands, a bioswale, and porous pavement. No new outfalls are proposed. Best management practices, including erosion control, are proposed. Conservation Commission Staff Report 2 October 24, 2019 If the Commission agrees that the work will not constitute an alteration, issue a negative determination by checking box 2, to indicate that the work is within an area subject to protection, but will not create an alteration and does not require an NOI filing. Include standard conditions. 6:00 PM - Continuation: Notice of Intent for residential driveway construction within buffer zone to wetland resource areas. Timothy Seney, 1087 Westhampton Rd, Map ID 41-70 The applicant has requested a continuation. Continue the hearing, with no discussion to be held tonight, until November 14 at 6:15 PM 6:20 PM – Continuation: Notice of Intent under the Northampton Wetlands Ordinance for construction of a new 3-story apartment building and related site and utility work within wetland resource areas and buffer zones. Dewey Court Properties LLC, 34 Dewey Court, Map ID 31D-217 The applicant has requested a continuation. Continue the hearing, with no discussion to be held tonight, until December 12 at 5:30 PM Request for Certificate of Compliance – Robert Foote, 94 Industrial Drive – 246-0658 The Commission granted an Order of Conditions in 2012 for additional storage units and related required stormwater mitigation. No-mow and restoration area were also required, and success of these areas has been demonstrated as required. A pavement expansion to accommodate an additional storage unit and related stormwater basin along the driveway on the southeastern property line were not completed. A partial certificate of compliance, noting this work not completed, can be issued. Request for Certificate of Compliance – Prospect Woods Homeowners Association, Warburton Way – DEP File 246-0707 The Commission issued an Order of Conditions in 2017 for driveway and stormwater work. The Order required reporting regarding the replication and restoration area to demonstrate that at least 75% cover of wetland species has been achieved, documentation that the annual maintenance plan for stormwater onsite has been incorporated into maintenance documents, and notification of street sweeping, which must occur at least once a year, and have not been to-date. Staff have communicated these missing items to the applicant, do not issue a certificate at this time.