Wetland Classification/ident/delineation-2007

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' , scientificall accurate consistenc with re y y gard to adherence to the vanous techmcal pubhcanons � and regulatory guidance documents. Circular 39 was authored by Shaw and Fredine and published by the U. S. Fish and W�7dlife 1 Service (USFWS) in 1956. The intended purpose of Circular 39 was an effort at classifying and inventorying wetlands on a national scale in order to assess the wetlamd bese and related waterfowl production potential. The classification process was never intecided to serve as a classification system for wetland regulatory purposes. However, since it was the first national � effort of its kind and as wetland regulatory intentions �terialized, this was the only method ava�able to differentiate between wetlands of different types. ' The Board of Water and So� Resources (BWSR) cross-reference table (8420.0549 subp. 2.) indicates that Circular 39 Type 3 wetlands have a "C" water regime modifier. This is an inaccurate cross-reference and the intent of this technical paper,is a clarification of the correct � interpretation. There is also a common tendency to refer to bottomland hardwoods as Type 7 wetlands. This is also an inaccurate classification. � The NWI paper maps do not use the water regnne modifier "E" because it was dif�icult to interpret &om the inherent limitations imposed by the remote sensed imnagery. Therefore, ir�ost if not all Type 3 wetlands were given the designation "C". However, the following discussion w�l , examine and clarify the differences between Circular 39 Types 1, 1L, 2, 3, and 7 and the appropriate Cowardin water regirr�e modifying tern�s. ` Circular 39 Wetland Types Type 1/1L—Seasonally Flooded BasL�s or Flats Type 1 wetlands are characterized by soil that is covered with water or is waterlogged during ' variable seasonal periods but is usually well drained during much of the growing season (italics added for emphasis). These wetlands may be found in upland depressions as well as in overflow bottomlands, i.e. river and stream floodplains. Within floodplains, flooding may occur in late , fa11, wurter or spring. In upland contelcts, basins or flats may be water filled during heavy rain events or following spring snow melt. Vegetation types vary greatly according to the season and , the duration of flooding. Included within Type 1 are bottomland hardwoods as well as some herbaceous growths. Where the water has receded early in the growing season, smartweeds, fall pamcum, tealgrass, chufa, redroot cypress and weeds (such as marsh elder, ragweed and � cockleburs) are 1�7cely to occur. Shallow basins that are sutxnerged only very temporan7y usually develop little or no wetland vegetation(Shaw and Fredine 1956,p30). ' Since Circular 39 was developed for national application, the description of Type 1 wetlands covers a broad range of geographic coirtexts hence the reference to winter flooding. Cowardin et a1 (p. 28) m Table 4 descnbe Type 1 wetlands as seasonally flooded basins or flats, wet meadow, � bottomland hardwoods and shallow fre.shwater swamps. The water regirnes are descn�bed as temporar�7y flooded(A) or internuttemly flooded(n. The Minnesota Dep�nent of Natural Resources (DNR), within the regulatory framework of the Protected Waters and Pubfic Wetlands framework has added the Type 1 L designator to �re ' clearly clarify the Circular 39 classification me�thod and to allow an accurate distinction to be made between bottomland hardwoods, seasonally flooded non-vegetated or herbaceous vegetated 1 basins and hardwood swarnps. The distinction on the basis of hydrology is clear and it was the Svoboda Ecological Resonrces 2180 Abingdon Way Project No.2007-056-03 Orono,Minnesota '