Wetland Classification/ident/delineation-2007

Home Browse Search

' � beneath the soil surface. The lan e "thro out the ow' season" is uite 'fic in � � �' � q � ' Circular 39. A careful consideration of the species descnbed 'm the listing provided by Shaw and Fredine (1956) indicates that ttie habitat requirements of the species listed include the typical presence of a near surface high water table whereas the descnption of a Type 1L forested , wetland descnbes the term "bottomlaund hardwood", a rather vague non-specific term but tree species generally included in this category are elm, cottonwood, green ash, and s�ver maple. Bottomland hardwoods do not mclude the species descn`bed as associated with hardwood , �'� Type 7 wetlands are persistently wet under all but the driest conditions whereas Type 1/1 L ' wetlands are generally dry except under the wettest of conditions. The distinction is significant. In general, the Board of Water and Soil Resources cross-ref�ence classification (Mn Rules , 8420.0549 subp. 2.) are generally accurate but the designation of PEMC as a Type 3 wetland poses some problems. Where the Type 3 wetland is comprised of cattails, a de minimus exer�tion of 400 square feet applies but where the wetland is reed canary grass, also a Type 3 � designation should technically apply based on the above discussion. The reed canary grass wetlands do not fit well into the "C" modifier category nor do they fit into the "B": modifier either. � As a matter of standard pra�ctice, it would seem best to designate reed canary grass wetlands as Type 2 wetlands regardless if the modifier is "B" of"C". The dif�erence is irriportant in that a de ' minimus exe�tion of anywhere from 2000 square feet to 10,000 square feet might be applicable. Also being accurate with regard to wetland type is ur�wrtant when designation of the regulatory wetland type is done based on if the deepest part of the basin or the dominant 1 vegetation is the wetland type that determines allowable fill. This requirement often over- regulates the reed canary grass fringe and eliminates the possi�ity of applying the 2000to 10,000 square foot de minimus in many cases where a very sma11 percentage of the overall basin ' is catta� but because the deepest part of the basin criteria is applied, only 400 square feet of de - minimus fill may be used. ' In general, wh�e this may seem to be an arcane discussion, in reality it is crucial in order for the regulated corrununity to rightfiilly claim the wetland exemptions that the law permits. Conversely, it entitles the landowner to rightfully claim useable land for development purposes. 1 A clear understanding and accurate interpretation of the classification system is necessary in order for the exernptions ava�able under the de minimus categories to be appropriately applied. ' , 1 ' Swboda Ecolo "cal Resources 2180 Abin don Wa 81 S Y Project No.2007-056-03 Orono,Minnesota 1