8.0 PRSR 03-09-2017 - Laserfiche WebLink

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i , TOPOGRAPHY AND SOILS TOPOGRAPHY The site has a generally flat topography,though the land slopes slightly to the rivers as it approaches the Elk to the west and the Mississippi to the south and east.To the north of the property,the land slopes noticeably upward to the neighboring residences,and some of this slope is captured in the northwest corner of the property. Here,the land slopes steeply upward from a slight depression west of the field edge up to the houses;this slope ranges from 6 to 35%,while the majority of the site is between 0 and 6%. Elevation of the site ranges from a low of 854 ft above sea level to a high of 872 ft in the northwest corner.The majority of the site ranges between 858 and 862 ft above sea level. SOILS Soils vary relatively little in character across the site and are heavily influenced by the river features. Most of the soils on the site are loamy soils, meaning that they are a mix of sand and silt,with clay composing a small fraction of the mix.These soils are nutrient and moisture rich and are ideal for agriculture.Along the river channel on the south end of the site,the soil is generally fine sandy loam, meaning it contains a large percentage of fine sand deposited by the river flow.These areas experience occasional flooding,which works to routinely deposit new soil.A summary of soils and their associated characteristics is listed in Table 1,and can be visualized in Figure 5. Soil formation is the result of the interaction of five soil-forming factors: parent material, climate,organisms,topographic position or slope,and time (Foth, 1990). Taken collectively,these factors can help determine the dominant floral and faunal communities that helped form the soils. Brodale, Copaston, Etter,Terril,Wadena, and Waukegan are all mollisolls,which are prairie soils,generally deep, dark in color,and rich in cations,and thus would have been dominated by graminoid vegetation (prairie or savanna) prior to European settlement.All of the soils of the project area are well drained or excessively well drained. None of them are considered hydric soils,which indicates that they are not wet enough for long enough to develop organic matter accumulations. Due to the fine,sandy nature of some of the soils,the erosion potential is mostly medium; none of the soil types present have a high erosion potential. Friends of the Mississippi River Bailey Point Nature Preserve NRMP 18