1987 Wetland Delineation Manual - The Wetlands Regulation Center
1987 Wetland Delineation Manual - The Wetlands Regulation Center
1987 Wetland Delineation Manual - The Wetlands Regulation Center
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<strong>Wetland</strong> Delination <strong>Manual</strong>, <strong>1987</strong> 63<br />
Subsection 2 - Soils<br />
74. Employ the following steps to determine whether hydric soils previously occurred:<br />
• STEP 1 - Describe the Type of Alteration. Examine the area and describe the type of<br />
alteration that occurred. Look for evidence of:<br />
a. Deposition of dredged or fill material or natural sedimentation. In many cases the presence<br />
of fill material will be obvious. If so, it will be necessary to dig a hole to reach the original soil<br />
(sometimes several feet deep). Fill material will usually be a different color or texture than the<br />
original soil (except when fill material has been obtained from like areas onsite). Look for<br />
decomposing vegetation between soil layers and the presence of buried organic or hydric soil<br />
layers. In accreting or recently formed sandbars in riverine situations, the soils may support<br />
hydrophytic vegetation but lack hydric soil characteristics.<br />
b. Presence of nonwoody debris at the surface. This can only be applied in areas where the<br />
original soils do not contain rocks.<br />
Nonwoody debris includes items such as rocks, bricks, and concrete fragments.<br />
c. Subsurface plowing. Has the area recently been plowed below he A-horizon or to depths of<br />
greater than 10 in.?<br />
d. Removal of surface layers, Has the surface soil layer been removed by scraping or natural<br />
landslides? Look for bare soil surfaces with exposed plant roots or scrape scars on the surface.<br />
e. Presence of man-made structures. Are buildings, dams, levees, roads, or parking lots<br />
present?<br />
Determine the approximate date (It is especially important to determine whether the alteration<br />
occurred prior to implementation of Section 404.) when the alteration occurred. This may<br />
require checking aerial photography, examining building permits, etc. Record on DATA<br />
FORM 3, and PROCEED TO STEP 2.<br />
• Step 2 - Describe Effects on Soils. Record on DATA FORM 3 a general description of how<br />
identified activities in STEP 1 have affected the soils. Consider the following:<br />
a. Has the soil been buried? If so, record the depth of fill material and determine whether the<br />
original soil is intact.<br />
b. Has the soil the original been mixed at a depth below the A-horizon or greater than 10<br />
inches? If so, it will be necessary to examine soil at a depth immediately below the plowed<br />
zone. Record supporting evidence.<br />
25 February 1997 Environmental Techncal Services Co. 834 Castle Ridge Rd Austin, Texas 78746