225 N CABOT RD 2019-10-04 - Laserfiche WebLink

I EXISTING SITE CONDITIONS The project site is located at the corner of North Cabot Road and Beverly Lane at 6832 North Cabot Road, Everett, Washington, within Everett City limits (Parcel #: 00392000000203). The project site is 0.27 acres. The existing round slopes to the west with slopes that range from 0% to 3% (Figure 1: Existing Site Plan). The site takes access from Beverly Lane from the northeast corner of the property through an asphalt driveway. The existing asphalt driveway extends to the west 150 ft along the north property line. There is an existing SFR located in the eastern portion of the property and a detached garage west of the existing SFR (Figure 2: Site Photographs). The rest of the property is a mix between lawn,pavers,and concrete. NRCS Soil Map (Refer to Section V) indicates on-site soils consist of Tokul type material. Tokul soils are a gravelly medial loam material that was derived from volcanic ash mixed with loess over glacial till. Tokul soils are moderately well draining with a Hydrologic Soil Group of "B". Seasonal high ground water is 18 inches to 36 inches below the ground surface. Mac Engineering dug a Test Pits (TP) in the western portion of the site on March 1st, 2017. On- site soils were found to be consistent with silty snad (Refer to Section V: Mac Engineering Soil Log). A soil sample was sent to Northwest Agricultural Consultants to determine the organic content and cat-ion exchange capacity for the existing top soil. On-site soil meets SMMWW Volume V, BMP T5.13 requirements; therefore, top soil can be stockpiled and replaced for final stabilization(Refer to Section V:Northwest Agricultural Report). Mac Engineering collected a soil sample for evaluation of infiltration rates through the means of Soil Grain Size Analysis per SMMWW Volume III, Section 3.3.6. On-site soils are consistent with silty sandy and contain less than 16% fines (Refer to Section V, Metron-Morgan Sieve Analysis). SMMWW Volume III, Section 3.3.6 was used to determine the initial (short term) infiltration rate and design (long term) infiltration rate (refer to Section V, Infiltration Worksheet). On-site soils have a design infiltration rate of 5 in/hr. Based on on-site field observations and sub-surface exploration, storm water run-off disperses and infiltrates into the existing native vegetation. There is no erosion issues present within the project site area. DEVELOPED SITE CONDITIONS The proposed project consists of removal of the existing detached garage and construction a building to turn the existing SFR in a duplex with attached garages. Storm water drainage analysis and flow controls, used to achieve best management practices (BMPs), design for this proposed development will comply with the minimum requirements set by Everett City Code and SMMWW Volume III and V. The proposed duplex (±3,765 sf w/overhang) which consists of the existing SFR, Unit B, and a new unit, Unit A, is classified as non-pollution generating impervious surface (NPGIS). The proposed duplex will be located in the center of the property (Figure 3: Developed Site Plan). 2