Laserfiche WebLink
WETLAND DEFINITION <br /> According to the 1987 U.S. Army Corps of Engineers "Wetlands Delineation Manual" (1987 <br /> Manual; the document used by all delineators to define wetlands) a wetland is "Those areas that <br /> are inundated or saturated by surface or ground water at a frequency and duration sufficient to <br /> support, and that under normal circumstances do support, a prevalence of vegetation typically <br /> adapted for life in saturated soil conditions." The Minnesota State Wetland Conservation Act <br /> Rules, Chapter 8420, further clarifies that "...wetlands must: (1) have a predominance of hydric <br /> soils; (2) be inundated or saturated by surface water or groundwater at a frequency and duration <br /> sufficient to support a prevalence of hydrophytic vegetation typically adapted for life in saturated <br /> soil conditions; and (3) under normal circumstances, support a prevalence of hydrophytic <br /> vegetation." The 1987 U.S. Army Corps of Engineers Manual in Part II, item 24. states that, <br /> "The interaction of hydrology, vegetation, and soil results in the development of characteristics <br /> unique to wetlands. Therefore, the following technical guidelines for wetlands are based on the <br /> three parameters, and diagnostic environmental characteristics used in applying the technical <br /> guideline are represented by various indicators of these parameters." It is this premise by which <br /> SER ecologists has, in their professional�judgment, delineated the wetlands on the subject parcel <br /> described in this report. <br /> Wetland Hydrology <br /> The most important wetland criterion is hydrology. The presence and persistence of water <br /> influences the vegetation types and changes soil morphology. Hydrology may be observed as <br /> standing water(inundation), or may be observed as freestanding water within the soil pit or auger <br /> hole (saturation) usually within the upper 12 inches. This is what would be considered primary <br /> hydrology indicators. Only one primary indicator is necessary to make the determination that <br /> wetland hydrology indeed exists. The 1987 Corps Manual also has a range of hydrologic zones <br /> established based on period of inundation or saturation. These zones and the periods of <br /> inundation or saturation for each can be observed in Table 1 below. <br /> Exce ted from the 1987 Manual,H drolo ic Zones—Nontidal Areas <br /> Zone Name Duration Comments Wetland or Not <br /> I Permanently Inundated 100% �undation>6.6 ft.mean Not(Aquatic Habitat Zone,or Deep Water <br /> water d th Habitat <br /> Semipermanently To Nearly �75_ Inundation defined as <br /> II Permanently Inundated Or �100% �6.6 feet mean water Wetland <br /> Saturated d th <br /> � Regularly Inundated Or �25-75% Wetland <br /> Saturated <br /> Seasonally Inundated Or <12.5- <br /> N Saturated 25% Wetland <br /> Irre larl Inundated or Many areas having these <br /> V � y >5-12.5% hydrologic characteristics Wetland(if hydrophytic veg.and hydric <br /> Saturated are not wetlands soils also present <br /> Intermittently Or Never o �'eas with these <br /> � Inundated Or Saturated �5/o hydrologic characteristics Not <br /> are not wetlands <br /> A-1 <br />