Agenda - Council - 04/23/2013 - Laserfiche WebLink

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Wetland Delineation Report Ramsey Station November 25, 2002 — Revised March 14, 2003 may be true, results of the aerial photo interpretation suggests portions of the swale historically had water ponded at or above the surface, especially in wet years. This indicates portions of the swale area were likely jurisdictional wetlands (farmed wetlands). The size of the wetlands depended upon the amount of precipitation received during the calendar year. During 1997 it appears hydrology was modified at the site and affected the swale and wetland areas. In October 1997, Halranson Anderson Associates performed a wetland -banking plan for impacts on construction of the County Road 116 extension project. The plan delineated a wetland on the subject property and proposed a wetland excavation (i.e. Wetland B) to compensate for existing wetland losses from the road project. Construction of County Road 116 occurred in 1997. The new load bisected Wetland C (as delineated in this report) and appears to have modified the natural drainage of the larger wetland complex. Wetland C has also been reduced in size through construction of the road and by right of way ditches located in County Road 116. The spoil from the mitigation wetland may have been used to raise the elevation around the banking project. It appears that water does not flow through the property as it did prior to 1997. Construction of the project and/or other recent man-made alterations have converted the classification of the wetland from a flow -through wetland from 1981-1997 to isolated wetland basins in 2002. Currently the entire swale area as shown in the aerial photos is now in agricultural production. Hydric soils exist in portions of the swale, but primary and secondary hydrologic indicators are lacking. Visible crop stress of the soybeans due to wetness was minimal Results of the aerial photo interpretation and the site visit indicate portions of the former swale area currently in agricultural production are not jurisdictional wetland areas. Therefore, these areas were not delineated as wetland areas based upon the following reasons: 1) lack of wetland hydrology; 2) lack of wetland vegetation; 3) elevation modifications around Wetland B; 4) no visible signs of crop stress; 5) construction of County Road 116 with designed drainage modifications; and 6) aerial photo interpretation. SUMMARY OF DISPUTED WETLAND CONDITIONS For the time period of 1981 — 1996 aerial photos indicated a flow through wetland existed, transecting the western half of the project site in a northwest to northeast direction. Interpretation during this time period suggested a predominance of type 2 (wet meadow) and type 3 (shallow marsh) wetland existed on the site. Changes in wetland hydrology were observed in the aerial photos beginning in 1997. Wetland hydrology for the following four years is progressively less with each year. Based upon the 2002 aerial photo for the project and field observations of the 2002 delineation, no indications of a flow through wetland existed at the site. Rather, the delineation fieldwork concluded the wetlands at the site were isolated wetland basins. Based upon fieldwork conducted by Emmons and Olivier Resources, a groundwater elevation study was conducted to evaluate if the wetlands were influenced by Page 5 of 52