10725 19TH AVE SE 2023-04-07 - Laserfiche WebLink

MR#1: Stormwater Site Plan Preparation I. Project Descri tion: J p The subject site is located at 10725 19t'Avenue SE in the city of Everett. The project site is situated on mostly flat ground and is bounded to the north,east,and south by existing developed residential properties and to the west by 19th Avenue SE. The project site is currently occupied by a single-family residence and detached outbuilding within the western and eastern portions of the property,respectively. Grass-covered yard and scattered landscaping plants surround the existing structures within the site. The proposed development would encompass the entire 0.4227 acre site with improvements consisting of removing all of the existing improvements including structures and driveway and constructing four,three- unit townhome structures with associated access driveway, utilities and landscaping around the perimeter of the site and along the frontage. The development of this project will occur in one phase.Developed impervious/pervious areas will be 0.2900 acre and 0.1327 acre,respectively. The following pervious and impervious areas are anticipated for the site: Develo ed im ervious area—Buildin Structures 7 512 SF-0.1725 Acre P P g Developed impervious area—Driveway 4,795 SF-0.1100 Acre Developed impervious area—Walkways 325 SF-0.0075 Acre Developed pervious area—Landscaping 5,180 SF-0.1189 Acre Developed pervious area—Pavers-600 SF—0.0138 Acre The upstream site area consists of developed both multi-family and single-family homes. Considering the site and surrounding area topography and through field observation,there are nominal amount of tributary runoff entering the site if any.No identifiable watercourses were observed crossing the site. Erosion control for the site will consist of filter fabric fences situated on the perimeter boundary of the site and by the installation of a rock construction entrance.Catch basin sediment control will be installed for all existing catch basins within the project limits and downstream in the vicinity of the project.The stormwater runoff from paved surfaces will be directed to a detention tank by a catch basin conveyance system.The site will be graded to sheet flow the runoff to the catch basins that will discharge to the detention tank.Roof runoff will be tight lined to the storm drain system. The detention tank will discharge to an existing storm drain system installed along the east side of 19th Avenue SE.