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Drainage Calculations for <br /> . • Richard A. Johnson property <br /> The subject property is Lot 4 and Lot 5, Silver Lake View Tracts, <br /> accordinq to the plat thareof recorded in Volume 8 of plats, paqe <br /> 65, records of Snohomish County, Washington. It is located on <br /> 19th Avenue SE south of 100th Street SE. <br /> The site is divided into two sub-basins for drainaqe anof the <br /> development purposes. The nature of and the hydroloqy <br /> eastern basin was discussed at length in an analysis prepared by <br /> Lovall-�auerland apecember11991. dT1�is basin/containssabminord to <br /> the Cit.y in early <br /> wetlan�i, which is required to be preserved. <br /> The western basin (includinq a small area of the eastern basin) <br /> basincoverslOn57f acrestof thepOS98 acres�thattconstituteStheThis <br /> site. A small commercial development has been proposed for this <br /> 0.57 acres. <br /> The proporty is less than 5 acres, and therefore it is not <br /> required for the City to calculate the storm water detention <br /> storage volume• <br /> �i�};no cond�tions <br /> The site was visually inspected on Novem..sr 21, 1991 by C. i <br /> Campbell. Antecedent weather was wet ar�d it was raining lightly <br /> at the time of the inspe1991n'to collect dataaonldifferences in <br /> occurred on December 5� eriod between the two dates. Tha <br /> site conditions during the p <br /> site soils seemad to be near saturation on both visits. <br /> Evidence of the removal of two buildinqs remainUeaLSA,tthere were <br /> Based on previously surveyed field topography Y <br /> two buildinqs on tThesremainderuof the sitetwaseshorta9rassnlawn. <br /> gravel driveway• es of cover are shown in the attached <br /> The areas for theae typ <br /> drainage calculations. <br /> � +„ra co*+ditions <br /> driv� p.216uacres�oftother impervious surfaces,�includinqd <br /> sidewalks and roofs, and conversion of the ramainder of the 0.57 <br /> watershed analysispmentionedAabovecurunoffnfrom thelroof oftoned <br /> assure it continueslt nreceive adequatatwatarrouThe wetlandawill� <br /> also be provided with an emergency overflow to =ogeTtiesaaret <br /> does not become so inundatedanSaforethebProJect reflect theae <br /> affected. The engineering p <br /> measures. <br />