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30A-032 2010 wetland-bank assessment November 16, 2010 Conservation Commission City of Northampton Office of Planning and Development 210 Main Street, Room 11 Northampton, MA 01060 RE: Cutlery Raceway Slope Stabilization, Wetland Restoration Monitoring Report 320-360 Riverside Drive Northampton, MA DEP File # 246-546 and #246-593 NEE File 02-2053-H Dear Members of the Commission, New England Environmental, Inc. (NEE) was hired by Alan Verson (the applicant) to assess the bank stabilization work at 320-360 Riverside Drive in Northampton and assess vegetational cover as required by the Order of Conditions. This work was originally completed in 2007 by Northeast Environmental Solutions (NES) under a “revised remediation plan” submitted to the Commission in a letter dated May 29, 2007. A site visit to complete this assessment was done on November 11, 2010. An NEE wetland scientist had previously visited the site on July 28, 2010. Both of these site visits were conducted by Karro Frost, PWS. To describe the vegetation on the site, the work areas will be described individually below. These sections include (1) the northern section of the levee with the retaining walls between the raceway and the Mill River; (2) the soil stockpile area on the levee which has been loamed and seeded; (3) original slope stabilization work completed adjacent to the former firehouse and cutlery building and their associated parking area; and (4) 2010 repair work completed in two sections within (3). The primary wetland resource area impacted by the work is the 200 foot Riverfront Area associated with the Mill River. Most of the work also occurred within the 100 foot buffer zone to bank. Northern Section of the Levee and Stabilized Bank Material was removed from this area under the 2004 Order of Conditions, and portions of the stone walls were rebuilt. Photos 1 through 4 (Attachment A) illustrate this area during the July and November site visits. The work went around pre-existing trees without damaging them. This area is well vegetated with an unidentified grass and scattered clover and tree seedlings. Only a few of the willow stakes survived and have grown. The percent cover is 85% in November, 2010. Wetland Restoration Monitoring Report -2-Cutlery Raceway NEE #02-2053-H DEP File # 246-546 and #246-593 320-360 Riverside Drive November 16, 2010 RTN #1-13220 Northampton, MA This area meets the criteria in the Order of Conditions for 85% vegetative cover. There is a silt fence at the toe of the slope which should be removed. Soil Stockpile Area The soil stockpile was created under the 2004 Order of Conditions, and then regraded, and stabilized in place under an IRA Amendment dated August 2006. The IRA Amendment was the result of a joint agreement between the Applicant, the City of Northampton Conservation Commission, and the DEP-BWSC-WERO. Under the IRA Amendment, the stockpile was covered with orange fencing as a marker, then covered with loam and seeded. This area now is completely vegetated, with no open areas and a percent cover of 100%. The dominant vegetation includes New England Aster (Symphyotrichum novae-angliae), wild rye (Elymus spp.) and deertongue (Dichanthelium clandestinum). Photos 5 and 6 in Attachment A illustrate this area on July 28 and November 11, respectively. A variety of other plants were also observed in this area including Queen Anne’s lace (Daucus carota), raspberry and blackberry (Rubus spp.), fall panic grass (Panicum dichotomiflorum), wavy-leaved aster (Symphyotrichum undulatum), tall goldenrod (Solidago altissima), burdock (Arctium sp.), red oak seedlings (Quercus rubra), bird cherry seedlings (Prunus pensylvanica), and sugar maple seedlings (Acer saccharum). A few exotic species pre-existing on the site have also started to colonize this area, including autumn olive (Elaeagnus umbellatus), Japanese knotweed (Polygonum cuspidatum) and multiflora rose (Rosa multiflora). This area meets the criteria in the Order of Conditions for 85% vegetative cover. Stabilized Slope Adjacent to Cutlery and Old Firehouse This area was stabilized under the 2004 Order of Conditions and the 2007 “revised remediation plan.” Work was done around pre-existing trees. This area includes very steep slopes. The canopy cover in this area is very dense and there is little light reaching the forest floor, preventing much growth in the herbaceous layer. This area has approximately 15% herbaceous cover, but 95% canopy cover. Portions of this area have slopes over 3:1, and the orange fencing is visible in sections on the slope. In addition, this area was minimally disturbed, with the primary activity covering the soil with orange fencing, which was then loamed and seeded. This area does not have any signs of erosion. Wetland Restoration Monitoring Report -3-Cutlery Raceway NEE #02-2053-H DEP File # 246-546 and #246-593 320-360 Riverside Drive November 16, 2010 RTN #1-13220 Northampton, MA Although the area does not meet the 85% herbaceous vegetation cover, it has 95% canopy cover. The area was minimally disturbed and shows no signs of erosion after three years. Smaller 2010 Repair Area -Upstream Immediately downstream of the above area is a small area of repair that was completed in spring, 2010. Unlike the above areas, this area was becoming undercut and was eroding. The total length of this repair is 30 linear feet. Repairs consisted of creating geo-lifts at the toe of the slope with brush layered between them, and soil covering the slope, seeded and covered with an erosion control blanket staked into place. Photos 8 through 10 in Attachment A illustrate this area. The vegetative cover of this area is approximately 20%. The vegetation is growing well and there is no further sign of erosion. Larger 2010 Repair Area – Downstream A second and larger area of bank repair was completed downstream and near the Cutlery Building. This area also was becoming undercut and the repairs were similar to the above. This area is 130 feet in length, and consists of biologs and geo-lifts at the toe of the slope with brush layering, and loam and seed were placed on the upper slope, which was then covered with an erosion control blanket. The grass has started to grow on the slope. Photos 11 and 12 illustrate this area. The herbaceous cover is approximately 50% and there has been no additional erosion. Canopy percent cover is 80%, with a total percent cover of approximately 90%. Summary Most of the site is well-vegetated, and the overall percent cover is 85% including the both canopy and herbaceous layers. The herbaceous layers in the 2010 repaired areas have not yet grown in to the density desired, however, they are expected to continue to expand and grow. The site was stable during both the July and November site visits conducted to assess the vegetation. ATTACHMENT A Wetland Restoration Monitoring Report -Photo Page 1 -Cutlery Raceway NEE #02-2053-H DEP File # 246-546 and #246-593 320-360 Riverside Drive November 16, 2010 RTN #1-13220 Northampton, MA Photo 1: The stabilized bank upstream of the Cutlery and Firehouse Buildings on the old levee has good coverage with grass. Other plants have started to colonize this area as well. Photo taken July 28, 2010. Photo 2: Overview of the stabilized bank upstream of the Cutlery and old Firehouse Buildings adjacent to the levee on July 28, 2010. Photo 3: The top of the levee looking south. The vegetation coverage in this area is very good. Photo taken on July 28, 2010 Wetland Restoration Monitoring Report -Photo Page 2 -Cutlery Raceway NEE #02-2053-H DEP File # 246-546 and #246-593 320-360 Riverside Drive November 16, 2010 RTN #1-13220 Northampton, MA Photo 4: Vegetated bank on November 11, 2010 upstream of the Cutlery and Firehouse buildings on the old levee. Photo 5: Looking south from the northern end of the soil stockpile towards the old firehouse. This area is 100% vegetated with herbaceous vegetation. Photo taken 7/28/2010. Photo 6: Soil stockpile from its northern looking south towards the old firehouse. This area is well-vegetated still on November 11. Wetland Restoration Monitoring Report -Photo Page 3 -Cutlery Raceway NEE #02-2053-H DEP File # 246-546 and #246-593 320-360 Riverside Drive November 16, 2010 RTN #1-13220 Northampton, MA Photo 7: Overview of the slope behind the old firehouse. Although this area does not meet the 85% herbaceous vegetative cover criteria due to a dense canopy (100% cover), it does not show any signs of erosion. Photo 8: A small area of bank repair near the old firehouse building. The sunlight shows how well the grass is growing on this repair. The black locust saplings were pre-existing and were not disturbed with the repair. Photo taken July 28, 2010. Photo 9: Photo providing a detail of the geo-lifts with brush layering. Photo taken July 28, 2010. Wetland Restoration Monitoring Report -Photo Page 4 -Cutlery Raceway NEE #02-2053-H DEP File # 246-546 and #246-593 320-360 Riverside Drive November 16, 2010 RTN #1-13220 Northampton, MA Photo 10: The smaller area of bank repair on November 11, 2010 from the toe of the slope. Photo 11: View of the larger area of bank repair located near the Cutlery Building, looking down the slope on July 28, 2010. Photo 12: View looking downstream of the larger area of bank repair, adjacent to the Cutlery Building.