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Seney Wton Road 50 Ft Buffer Narrative and Sketch 8-1-19.pdf James A. Gracia, PE 99 Glendale Street, Easthampton, MA 01027 August 1, 2019 Additional Information: NOI filed on behalf of Timothy J. Seney for 1087 Westhampton Road In regard to work proposed within the 50’ Buffer zone, the proposed disturbance within 50’ of the wetland boundaries were necessary due to the limited amount of room to construct the driveway between three separate wetland areas and two separate property lines of abutters. Due to the topography, the driveway profile had to be raised slightly at the beginning section of driveway and then transition into a cut as it traversed up a steep incline. The abutter to the east was concerned about a driveway being close to his property line, therefore, an effort was made to maintain as much separation from his property line as feasible. The fill required to provide a reasonable grade for the driveway profile pushed the driveway farther away from the property line so as not to add fill too close the line. As a result this pushed the driveway further away from the wetland on the easterly side, but closer to the wetland on the westerly side of the driveway. There are four separate incidences of disturbance within the 50’ Buffer Zone. As can be seen on the attached cut from Sheet 2 of the work plans, the first disturbance consists of 1864 SF within the 50’ Buffer. The driveway surface itself, accounts for a very small amount of this area, approximately 59 SF. The remainder of the disturbed area is due to the fill required to meet existing grades along the easterly side. A manageable grade of 3H:1V has been maintained along the side slopes to minimize erosion of the slope. As described in the NOI narrative, the first 350 LF of driveway shall allow surface runoff to sheet flow over the side slopes. A steeper grade on the side slopes would be more difficult to prevent erosion in the long term, therefore, the more gentle side slopes have added to the area of disturbance. The second area of disturbance consists of 2692 SF in area. This is predominantly due to the stormwater drainage swale and settling pool which extends out toward the easterly section of wetland. The driveway surface itself is just outside of the 50’ Buffer. The drainage swale and settling pool could conceivably be closer to the driveway, but the change in grade along the swale would be steeper in order to meet the existing grade with the settling pool perimeter. The next disturbance consists of 2887 SF in area. As mentioned above, the driveway was pulled away from the abutter’s property corner to provide a reasonable amount of separation between the property line and the bottom of the filled slope. As can been seen on the cut sheet, the driveway surface itself fits exactly between the two 50’ Buffer Zones for the easterly and westerly wetland areas. The final 50’ Buffer disturbance consists of 2730 SF in area. As in the previous disturbance, a majority of this square footage is due to the drainage swale and settling pool. Another very small area of the actual driveway surface, approximately 54 SF, falls within the 50’ Buffer. Within the cut section of this driveway corridor, the side slopes were graded at 2H:1V, which saved a fair amount of disturbance as opposed to being James A. Gracia, PE 99 Glendale Street, Easthampton, MA 01027 Seney NOI 1087 Westhampton Road (continued) graded at 3H:1V in the fill sections. Surface water sheet flow will travel over these cut slopes, but it will be much less when coming from the undisturbed existing vegetated landscape, than coming from the driveway surface and across the fill slopes at the lower section of the driveway. Another factor, which comes into play with this last area of disturbance within the 50’ Buffer, is that the Buffer Zone at this location is severely extended due to a small Isolated Vegetated Wetland, 598 SF in area. The original wetland delineation, performed by Emily Stockman in June 2015, did not include this small area of wetland. Evidently, she did not consider it to be a regulated wetland, for whatever reason. The person doing the updated wetland delineation did consider it to be regulated and flagged it as such. This small seasonal depression is the sole reason for the last area of disturbance within the 50’ Buffer Zone. One last factor in this discussion concerning the proposed amount of disturbance within the 50’ Buffer Zone is that when laying out the erosion control barrier/limit of work line, it was done with the idea of providing a reasonable amount of room for the excavation contractor to do the work required to build this driveway. All efforts will be made to minimize the tree cutting to only that which is absolutely necessary. For the reasons listed above, we are requesting that the proposed disturbance within the 50’ Buffer zone be allowed under this Notice of Intent.