2119 103RD ST SW A,B 2017-03-13 - Laserfiche WebLink

DYNASTY EAST DUPLEX Minimum Requirement # 1 : Stormwater Site Plan Executive Summary The proposed project consists entirely of clearing/grading for the construction of a new duplex residence with associated access driveway and drainage improvements. The proposed duplex is to have an approximate roof area of 3,001 sf.,with an approximate concrete walkway area of 849 sf. and a proposed driveway area of 1,130 sf. Total new/replaced impervious surface shall be approximately 4,980 sf. Drainage management for the proposed roof area will be provided by dispersion trench BMP. Driveways to slope into adjacent vegetated areas per BMP 12.70. Disturbed pervious areas will be amended per BMP 12.20. Existing Conditions Summary The property is one parcel and consists of existing second/third growth forest area. The northern portion of the site contains an existing Type Ns stream with associated buffer areas. Upstream Analysis The topography of adjacent areas tends to slope northeasterly. Minor sheet flows are expected from proposed lawn areas on the parcel to the west. A ditch line along the north side of 103rd Street SW conveys road runoff away from the site. Downstream Analysis A downstream analysis was provided by Timothy Sarkela, E.I.T. of Western Engineers & Surveyors Inc, on November 3, 2015. Weather was overcast with a temperature around 50 degrees. The property tends to slope northerly and westerly toward an on-site/off-site Type Ns stream within the northern portion of the property and to the east of the property (see photos 1 through 3). As this is the closest receiving water, further visual downstream inspection is not required. Drainage Complaints There are no found drainage complaints for this site. WESI 2 PROJECT: 14-1366-A EAST