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. <br /> Cowardin �ater Regime 1Vlodifiers <br /> The purpose of water regime modifiers is to provide .a better descr'iption of the variations in <br /> h:ydrology that occur in vvetlands on a seasonal and annual basis. These descriptions are general <br /> in nature because wetland hydrology is extraordinarily dynamic. .Iiydrology is fhe most variable <br /> coinp.�nent of wetlands and cai� vary substantially within a sinble basin weel:ly, monthly, <br /> seasonally, annually and over decades. Extraordinarily wet or dry periods, whether short or <br /> prolonged, do fia�e dramatic effects on the presenee or absence of water in any given wetland. <br /> Whether a°wetland has naturally occurring hydrology or whether. it is partially or completely <br /> drained affects its beha�+ior.as a component of the ]andscape, its appearance, the vegetation that <br /> inhabits �it, an� the effectiveness of the funetions that it performs. Wetlands may also have <br /> artificially�induced hydrology due to sCormwater inputs or interconnections to other wetlands via <br /> ditch or tile drain�systems. Careful. consideration of each w�tland within the overall context of <br /> the landscape is necessary to understand which water regime best fits along with �e special <br /> modifiers ihat describe alterations to we�lands. <br /> One special modifier:class that 'is missing is the"stotmwater pond" category.This is a commonly <br /> occurring condition in urban landscapes.and should be added. Stormwater ponds may have been <br /> specifically constructed'for that purpose or,in the past,previously existing wetlands were used to <br /> treat stormwater and now.function�as stormwater ponds rather than"natural"wetlands. <br /> Descriptions-of:the modifiers are taken from<Cowardin et al(1979,pgs 21.—22) and from Santos <br /> and Gauster(1993,pgs 30—32). " <br /> Descriptions with'in the parentheses are terms used on ehe NWI key and the longer description is <br /> the one used by Gowazdin et al. (1979). Where a parenthetical term is excluded, the two terms <br /> are the same. � <br /> Mod�er��A" � <br /> Temporarily Flooded{Temporary� <br /> Surface water is present for brief periods during:the growing season but the water table usually is <br /> � weIt below the :soil surface for most of the season. Temporarily flooded wetlands usually have <br /> plants tnat aze characteristic of both uplands and wetlands: This modifier descrigtion is most <br /> appropriately assigned to Type 1 and I:L wetlands buf clearly does not fit ihe Type 7 Hardwood <br /> Swamp wefland type. Table 4 (Cowardin et al 1979; gg 28) 1s inconsistent by including fihis <br /> regime:in the Type 7 category. . <br /> Modifier"B" <br /> S�turated <br /> Soil saturatiori occurs Co the surface for extended periods during the growing season but surface <br /> water is seldom present or evident. Ivlany 5edge and rush weClands fit into this category. This <br /> modifier also aptly fits the water.regime that occurs in the hardwood swarnps that are present in � <br /> parts of Minnesota in hardwood swamps such as black ash swamps and in coniferous s��vamps <br /> suc� as white cedar, tamarack, and black spruce swamps. This modifier also describes Type 2 <br /> wetlands as described above and includes fens and sedge/rush daminated�uetlands. <br />