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Snohomish.County Area, Washington 13
<br /> is slight. A seasonal perched water table is at a depth of The main limitations of the Alderwood soil for
<br /> 18 to 36 inches from January to March. homesites and septic tank absorption fields are the
<br /> Urban land is areas that are covered by streets, depth to the hardpan and wetness because of the
<br /> buildings, parking lots, and other structures that obscure seasonal perched water table. Drainage is needed if
<br /> or alter the soils so that identification is not possible. buildings with basements and crawl spaces are
<br /> The Alderwood soil in this unit is used mainly for constructed. Onsite sewage disposal systems often fail
<br /> 0 parks, building sites, lawns, gardens, and woodland. or do not function properly during periods of high rainfall.
<br /> The main limitations of the Alderwood soil for Topsoil needs to be stockpiled during site preparation
<br /> homesites and septic'tank absorption fields are the and subsequently used to cover the exposed underlying
<br /> depth to the hardpan and the seasonal perched water material. Additions of fertilizer and peat are desirable
<br /> table. Onsite waste disposal systems often fail or do not prior to seeding grass for lawns.
<br /> function properly during periods of high rainfall. Drainage This map unit is in capability subclass IVe.
<br /> is needed if buildings with basements and crawl spaces
<br />. are constructed. Topsoil needs to be stockpiled during . 7—Bellingham silty clay loam. This very deep, :,•.orly
<br /> site preparation and subsequently used to cover the d fined soil is in depressional areas. It formed in
<br /> exposed material. Additions of fertilizer and peat are all ium and lacustrine sediment. Areas are regu:r in
<br /> desirable prior to seeding grass for lawns. sha and are about 2 to 25 acres in size. The ative
<br /> This map unit is in capability subclass IVe. veget tion is mainly grass and sedges. Elevation is 50 to
<br /> 800 feet. Slope is 0 to 3 percent. The avera.- annual
<br /> 6—Alderwood-Urban land complex, 8 to 15 percent precipit tion is about 45 inches, the averag: annual air
<br />. slopes.This map unit is on till plains. Areas are irregular temperature is about 50 degrees F, and th- average
<br /> in shape and are 25 to 100 acres in size. The native frost-free season is 160 to 180 days.
<br /> vegetation is mainly conifers and hardwoods. Elevation is Typically; the surface layer is very dar gray silty clay
<br /> 50 to 550 feet. The average annual precipitation is about loam about inches thick. The subsoil o a depth of 60
<br /> 40 inches, the average annual air temperature is about inches or mo e is mottled, gray and o ve silty clay.
<br /> 50 degrees F, and the average frost-free season is 170 Included inks unit are small are.. of Terric
<br /> to 190 days. Medisaprists, very poorly drained o manic soils, Norma
<br />• This unit is about 60 percent Alderwood gravelly sandy soils along upland drainageways, itsap and Pastik soils
<br /> loam and about 25 percent Urban land. The components on terraces, and Bellingham soil- that have been
<br /> Included
<br /> of this unit are so intricately intermingled that it was not drained. areas make uo about 10 percent of the
<br /> practical to map them separately at the scale used. total acreage.
<br /> Permeability of this'`Bellingam soil is slow. Available
<br /> Included in this unit are small areas of Everett and water capacity is high\Effec ve rooting depth is limited
<br /> Indianola soils on terraces and outwash plains, Kitsap by a seasonal high water table that is at a depth of 0 to
<br /> soils on terraces and terrace escarpments, and Ragnar
<br />•
<br /> soils on outwash plains. Included areas make up about about 12 inches from Nbv tuber to June. Runoff is veryslow, and the hazard of , ter erosion is slight. Ponding
<br /> 15 percent of the total acreage. occurs from November ,o lune.
<br /> The Alderwood soil is moderately deep and This unit is used for pasture, woodland, urban
<br /> moderately well drained. It formed in glacial till. Typically, development, and wildlife h\bitat.
<br /> the surface layer is very dark grayish brown gravelly This unit is suited to pasture if the excess water on the
<br /> sandy loam about 7 inches thick. The upper part of the surface is removed.Cfile drains or open ditches can be
<br />,A subsoil is dark yellowish brown and dark brown very used if suitable outlets are available. Grazing when the
<br /> gravelly sandy loam about 23 inches thick. The lower soil in this unit is v'et results in 'Compaction of the
<br /> part is olive brown very gravelly sandy loam about 5 surface layer, por tilth, and reduced infiltration. Use of
<br /> inches thick. A weakly cemented hardpan is at a depth proper stocking ates, pasture rotation, and restricted
<br /> of about 35 inches. Depth to the hardpan ranges from grazing during*et periods helps to keep the pasture in
<br /> 20 to 40 inches. good conditions. Proper grazing prat\ices, weed control,
<br /> Permeability of the Alderwood soil is moderately rapid and fertilize:rare needed for maximu quality of forage.
<br />• above the hardpan and very slow through it. Available This unit r4 suited to red alder. On t e basis of a 50-
<br /> water capacity is low. Effective rooting depth is 20 to 40 year site curve, the mean site index is 3. The mean
<br /> inches. Runoff is slow, and the hazard of water erosion annual inofement at culmination (CMAI) or red alder at
<br /> is slight. A seasonal perched water table is at a depth of age 40 isi89 cubic feet per acre. A.mong\che trees of
<br /> 18 to 36 inches from January to March. limited yam`tent on this unit are Douglas-fir, igleaf maple,
<br /> Urban land consists of areas that are covered by western( redcedar, and western hemlock. A ong the
<br /> streets, buildings, parking lots, and other structures that comn)on forest understory plants are trailin blackberry,
<br />• obscure or alter the soils so that identification is not west rn swordfern, thimbleberry, salmonber , and
<br /> possible. huc ieberry.
<br /> The Alderwood soil in this unit is used mainly for T e main limitation for the harvesting of tim er is soil
<br /> parks, building sites, lawns, and woodland. w ness, which limits the use of equipment to
<br />• 6g
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