11030 7TH AVE SE 2018-01-02 MF Import

I yyH 9 y y Mr. Roddy Cox H3 October 11, 1988 HEM Page -2- o x o No obvious evidence of significant soil disturbance exists in ti N this region. To the east of this band, the ground rises 2 to 4 HqZ feet to an area which clearly displays upland vegetation and soil oo characteristics. H t7 CM g Vegetation in the region adjacentto the creek is characterized by dense stands of Red Alder (Alnus rubra), and i+ scattered Vine Maple (Ace r circinatum) and Salmonberry (Rubus y soectabilis). The vegetation exhibits characteristics of riparian x H H or floodplain vegetation, not forested wetland. The expected grn H ground flora component is missing. The consistent age of the trees o trA and the lack of well developed understory and groundflora suggests that either this area has been recently disturbed, or it is H repeatedly impacted by flooding. However, the creek bank does not y p y exhibit signs of recurring flooding. Soils ir.'his area consist of about one foot of loose gravelly sandy loam underlain by sand and gravel. A dense layer of glaci.l till can be found at between 2 and 3 feet. The upper soil layers are light brown to reddish brown in color with no mottles or other indications of an active water table. The soils would not be classified as hydric or wetland soils. The hydrology of the area is primarily controlled by North Creek. Although no evidence of surface water was found outside the creek channel, it is possible that the creek does flood the areas within the level plain. Groundwater in association with the creek exists on top of the till during wet months, but does not appear to be present in quantities to impart hydric characteristics to the top 18 inches of soil. CONCLUSIONS At present, there are no areas east of the creek on the site which meet the criteria for wetlands. The lack of wetland vegetation and the upland characteristics of the soil would iR classify the area as upland. The nearly level plain which parallels the creek and averages about 8o feet in width displays characteristics of a floodplain which is inundated on an infrequent basis. Management of this plain should proceed under the assumption that the limiting factors to development are associated JZ with floodplains and riparian zones rather than wetlands. Neither the Federal Emergency Management Agency, Snohomish County, nor the City of Everett have mapped she floodplain in the project area. The City of Everett has, however, estimated flows for this section of North Creek (Dan Mathias, Everett Public Works). Using this information, an engineer would be capable of calculating what portion, if any, of the site would be inundated during a flood event.