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Northern Avenue April 2009 NOI project narrative FINAL sub… NOTICE OF INTENT NORTH STREET CONDOMINIUMS PROJECT NARRATIVE This Notice of Intent is being submitted to the Northampton Conservation Commission for the construction of a 23-unit townhouse condominium project, with associated roadway and stormwater management system, on property consisting of 2 parcels totaling approximately 5.6 acres, located ½ mile from downtown. Existing Conditions The property is located off View Avenue, a private way off North Street owned by the applicant, and off the end of Northern Avenue. There is an intermittent stream that flows from the Industrial Park on the north, through a culvert under the new bike path and along the northwesterly edge of the subject property. The stream is also fed by the storm drain system on Northern Avenue, which flows into the swale adjacent to the bike path. There are bordering vegetated wetlands associated with the intermittent stream. The property slopes gradually and drains toward the BVW. The wetland and areas of upland within the wetland have some significant native trees, but there are also many invasive plant species in the area, including oriental bittersweet, Japanese knotweed, multi-flora rose, honeysuckle, and poison ivy. The adjacent uplands on the eastern half of the property contain even greater concentrations of invasive plants and are also degraded by historic filling, masonry and other construction and road building debris. The property has an existing house near View Avenue, for which a demolition permit has already been obtained. The house is surrounded by lawn, with a low stone wall at the edge of a portion of the lawn, and a plantation of non-native Norway Spruces beyond the lawn towards the west. Invasive species are common in these western upland areas, although not as predominant as in the eastern upland portions of the property. Proposed Work The proposed project consists of a duplex on Northern Avenue and 21 townhouse condominiums off North Street, for a total of 23 new dwelling units, with associated roadways, parking areas, driveways, sidewalks, utilities, landscaping and stormwater management system. There is approximately 2.1 acres of Bordering Vegetated Wetland. No alteration of any resource area is proposed, but a portion of the project falls within the 100-foot Buffer Zone of the BVW. The six buildings, each containing 2-6 units, fall (at least in part) within the 100-foot Buffer Zone. All proposed work is outside the 35-foot wetland buffer. The 35-foot buffer shall remain a permanent No Disturb Zone. There is one detention basin and two rain gardens, each located within the 100-foot Buffer Zone. All grading, pipes and outfall structures are kept at least 35 feet from the BVW. One hundred percent of the roof run-off is infiltrated through the use of linear dry wells adjacent to the units, and 2 rain gardens. Because of the Type C soils on the site, the project is only required to infiltrate runoff to the maximum extent practicable per DEP stormwater regulations. However, the project actually meets the DEP standard for infiltration of 65% that is required on sites with soils that are better drained (soil Types A and B). The project infiltrates 66% of the new impervious area. In order to further maximize infiltration on site, all BMPs have been designed to hold twice the recharge volume directed to them. Additionally, snowmelt is infiltrated in two snowmelt trenches located adjacent to unit 1 and unit 15. All road run-off is pretreated before it enters a detention basin. Mechanisms to treat water quality include the two rain gardens, six drywells, a proprietary treatment chamber, and deep sump hooded catch basins. 1 Utilities will be installed to service the lots as follows: Sewer: All units are serviced by the City sewer system. Water: All units are serviced by the City water system. Electric, Telephone and Cable Systems: All units are served by underground services. Natural Gas: All units are served by underground gas service. No work is proposed that will enter or alter the 2.1 acre Bordering Vegetated Wetland resource areas. Relationship to the Northampton Wetlands Protection Ordinance The North Street condominium project is located in the URB zoning district, which is a district that is already densely developed and where the City seeks additional development per its approved Sustainablility Plan. The North Street Condominium development is a true infill project, sited within the context of preexisting residential neighborhoods, and providing attractive residential options within easy walking distance of schools, jobs, retail establishments, restaurants and entertainment. Section 337-10(B) of the City Code states that “To encourage infill development, which is considered more sustainable under the principles of smart growth and generally has a smaller environmental footprint than development in outlying areas, in …Urban Residential-B… Zoning Districts, the Conservation Commission hereby waives any of the § 337-10 performance standards that are over and above state law with the exception of the setback requirements in Table (1): Zoning District No-Encroachment Zone Urban Residential-B and Urban Residential-C 35 feet from wetlands; 10 feet from wetlands may be allowed at the discretion of the Conservation Commission if applicant provides extraordinary mitigation, replication, restoration or open space preservation measures The plans show all work, including buildings, grading, walls, yards, patios, and all components of the stormwater management system, at least 35 feet from the BVW. Additionally, of the 23 units, all but 3 are outside the 50-foot wetland buffer, and most of the roadways, driveways and parking areas are outside the 100-foot buffer. The plans also show mitigation for buffer zone impacts which improve the condition of the buffer zone (“adjacent upland area”) in accordance with Section 337-10(E)(2): The City's general policy is no encroachment within 50 feet of wetlands. The Commission may allow work within the fifty-foot non-encroachment zone in response to a written request for a waiver, which shall include a written and plan view assessment as part of the application process as follows: (b) Projects in certain infill areas, in accordance with Table (1) in § 337-10, where development includes mitigation measures that will improve the existing condition of the wetlands or adjacent upland area and is otherwise permissible under the Massachusetts Wetlands Protection Act. While there is some inconsistency in the sections of the Northampton Wetlands Protection Ordinance quoted above regarding the local requirement for mitigation for work within the 35-50-foot buffer zone for infill projects in URB, we hereby request a waiver of the general policy of no encroachment within 50 feet of wetlands, and are proposing mitigation measures as described below. 2 Bordering Vegetated Wetland Delineation Method The boundaries of the Bordering Vegetated Wetlands on site were flagged by Chuck Dauchy using wetland vegetation and soil indicators, and were accepted by the Northampton Conservation Commission with a positive determination issued August 24, 2007. A copy of the Determination is attached to this Notice of Intent. Erosion Controls During Construction Erosion controls will consist of entrenched silt fencing, located no closer than 35 feet to the wetland buffer as shown on the plan. This will be the limit of work line. Erosion controls will remain in place until construction is complete and exposed soils have been successfully stabilized by vegetation. Mitigation of Potential Impacts to Resource Areas All invasive plants within the areas of the 10-35 foot buffer zone hatched on the plan and located primarily but not exclusively behind units 14-21, will be removed and replaced with native plants with high wildlife value. While this area will be the focus of invasive plant removal since the density of invasive plants in this area is greatest, other invasive plants throughout the entire site that are located 10 feet or more from the wetlands will also be removed. They will be replaced with native plants where the density of invasive plants removed is great enough that replanting is required. All work will be done by hand, with no equipment to enter the 35-foot buffer zone. All replacement plants will be nursery grown, and will include species listed on the plant schedule under “Native Species Planting Buffer.” The significant stand of Japanese Knotweed in the 10-35 foot buffer zone hatched on the plan behind units 11-14 will be eradicated and the buffer restored. We will use the following strategy, a combination of initial hand removal of the knotweed followed by chemical treatment, both based on the Nature Conservancy’s Best Management Practices found on various websites. 1. After initial re-growth of knotweed in spring and before flowering in early July, stalks will be cut down, and as much of the root stock and seed source as possible will be removed. 2. Cuttings and rhizomes will be burned or placed in tough black plastic bags in the sun to “melt” outside the 100-foot wetland buffer for at least one month, and then removed from the site. 3. After August 1 and before frost, any new knotweed stalks will be cut approximately 2 inches above ground level. 4. A very small area of knotweed will be cut at a time and a 25% solution of glyphosate (e.g., Rodeo, which is preferable to Roundup since the application will be near wetland areas) will be immediately applied directly into the stem cavity as well as the cut surface via hand wiping, dripping and/or stem injection. This work will be performed by a licensed herbicide applicator. 5. Any new cuttings will be burned or placed in tough black plastic bags in the sun to “melt” outside the 100-foot wetland buffer for at least one month and then removed from the site. 6. The area will then be densely replanted with native trees and shrubs following the planting plan and schedule, to provide shade to help prevent the reemergence of knotweed. 7. The process will be followed for 5 years, as continued vigilance and multiple applications of herbicide to the cut stems of any knotweed re-growth will be required over the years to keep the knotweed from reestablishing. Chemical treatments will take place after August 1 of each year since treatments in late summer or early fall are much more effective in preventing re-growth of Japanese knotweed the following year. For the record, it would be far easier to control the knotweed if it could be removed in its entirety (right down to the edge of the wetland). However the Northampton Wetlands Protection Ordinance, in its current form, does not permit such work closer to the wetland than the 10 foot buffer. The existing lawn area between the 10-foot and 35-foot buffer behind units 1 and 11-14, will be converted to functional buffer zone through re-vegetation. The lawn area will no longer be mowed or cultivated in any way, and native tree and shrub species with high wildlife habitat and forage value will be planted in accordance with the planting plan and schedule. 3 In addition, native plantings of trees and understory shrubs will be installed by hand just within the 35-foot buffer zone and on the side slopes of the detention basin, as shown on the plan. This planted buffer edge will improve the wildlife habitat value of the existing buffer by providing wildlife cover, edge habitat and high quality forage. Wetland markers, clearly visible at 18 inches above grade, have been installed to mark the location of the approved wetland flags and will remain in place during construction. Afterward, they will be hammered flush with the ground and left in place permanently. The 35-foot No Disturb Zone will be marked as follows: • A portion of the 35-foot No Disturb Zone will be marked by the edge of a paved footpath, which is actually located at approximately 37-38 feet from the wetland. This path will be the limit of activity and use behind units 1-4 and units 15-19 and, along with a retaining wall, will form the edge of the common open space between these units. • The rest of the 35-foot No Disturb Zone, with the exception of the area around the detention basin, will be permanently marked by concrete bounds, set 2 feet above ground and spaced no more than 25 feet apart. Each bound will be clearly labeled “Wetland Buffer – Do Not Disturb.” • The topography of the detention basin itself provides a clear edge to the 35-foot No Disturb Zone. The basin provides a physical barrier that goes further from the wetland than the 35-foot No Disturb Zone, and it is not an area that will ever be used by people or potentially expanded. • A buffer of native trees and/or understory shrubs will be planted by hand along the entire 35-foot wetland buffer, including along the wetland side of the foot path and on the outside slope of the detention basin. This will provide a visual edge that demarcates the No Disturb Zone. We are also proposing a comprehensive Declaration of Covenants and Restrictions in order to relieve the Conservation Commission of responsibility for inspecting and enforcing the integrity of the 35-foot No Disturb Zone to the maximum extent practicable. We are proposing that the Condominium Association hire a professional acceptable to the Conservation Commission to inspect the No Disturb Zone annually and issue a report to the Commission in conjunction with the annual report on the condition of the storm water system and its maintenance. An escrow account will be established with signatory powers given to the City of Northampton that will make funds available for either inspections not performed or remedial measures if needed, in the event the Condominium Association fails to comply with requirements for continued monitoring and any necessary maintenance or restoration of the 35-foot No Disturb Zone, or with requirements of the Stormwater Management Plan. We have included with this Notice of Intent a draft of the sections of the Declaration of Covenants and Restrictions that are pertinent to the Conservation Commission and its jurisdiction, specifically sections titled “Storm Water Management,” Snow Removal and Management Plan,” 35-Foot Wetland Buffer No Disturb Zone,” Common Open Space,” and “Escrow Account.” We expect that the Declaration of Covenants and Restrictions will be finalized with the assistance of Planning and Conservation Staff, and will incorporate all conditions of permit approval. Additional Information USGS Location Map City of Northampton Wetlands Application WPA Form 3 – Notice of Intent Notification Sent to Abutters Abutters List for Map 25C, Parcels 12 and 17 Summary Stormwater Report Draft Sections of Declaration of Covenants and Restrictions Determination of Applicability, Issued August 24, 2007 “Site Plan” by the Berkshire Design Group, dated April 14, 2009 Full Stormwater Report 4