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proposed R/D pond to act in desiitation of storm water before release <br />tothe downstream property_ <br />TASK 2. Resources to be Reviewed: <br />■ DHA Offsite Analysis Plan - See page 3a. <br />■ City of Everett Aerial Topo Map on page 3b. <br />■ Soil Survey Letter by Wetlands Resources, Inc. dated 3/2/98 on page <br />3c <br />TASK 3. Inspect Study Area Discussion <br />The offsite analysis area is from 108th St SW to 112th St SW and west <br />of Evergreen for about 650'. The storm drain just constructed on 108th carries <br />any upstream flows in the Swamp Creek Basin to the east. The onsite <br />construction of ecology blocks and fill have an affect on and cuts off the outiet <br />from the infiltration trenches in the existing duplex lot from flowing south. <br />This bit of upstream flow will be vented as shown on the DHA plan. The <br />main onsite storm flow will be absorbed in most of the new soils on site before <br />it overflows - unless saturated by probably a 100 year storm. The planned R/D <br />dry pond and pickup ditch should detain and release in some form of sheet <br />flow with the maniford pipe oulet system. <br />The downstream 1/4 mile which is to the south and southwest of the <br />natural discharge point is forested and covered with blackberry vines in the <br />northern one-third part. On May 2, 1998 the site was visited, topo shots were <br />taken on site and on 112th st sw and the downstream forested 15 acres was <br />researched going north from 112th st. <br />The forest area, as shown on the Offsite Analysis Plan on page 3a, was <br />covered with blackberry vines prohibiting extensive topo survey. The lower <br />twolthirds of this 15 acres is posted as wetlands, so shrubs and vines were not <br />cleared to get line of sight for topo. The fnllowing is a discussion of the field <br />review done with these restrictions. <br />See page 3a, the Offsite Analysis Plan; page 3d for the Off-site Analysis <br />Drainage System Table for the drainage items discussed below <br />Item A is the natural discharge poiint which is at approx. 80' east of the <br />southwest comer of the 2 project parcels. Flow type is sheet flow going <br />