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> 41<br />
• STEP 3 - Determine Whether <strong>Wetland</strong> Hydrology Is Present. When one of the following<br />
conditions applies (STEP 2), it is only necessary to confirm that there has been no recent<br />
hydrologic alteration of the area:<br />
a. <strong>The</strong> entire project area is occupied by a plant community or communities in which all<br />
dominant species are OBL (Appendix C, Section 1 or 2).<br />
b. <strong>The</strong> project area contains two or more plant communities, all of which are dominated by<br />
OBL and/or FACW species, and the wetland-nonwetland boundary is abrupt (e.g. a Spartina<br />
alternifzora marsh bordered by a road embankment). * <strong>The</strong>re must be documented evidence of<br />
periodic inundation or saturated soils when the project area:<br />
a. Has plant communities dominated by one or more FAC species;<br />
b. Has vegetation dominated by FACW species but no adjacent community dominated by OBL<br />
species;<br />
c. Has a gradual, nondistinct boundary between wetlands and nonwetlands; and/or<br />
d. Is known to have or is suspected of having significantly altered hydrology.<br />
If either a or b applies, look for recorded evidence of recently constructed dikes, levees,<br />
impoundments, and drainage systems, or recent avalanches, mudslides, beaver dams, etc., that<br />
have significantly altered the area hydrology. If any significant hydrologic alteration is found,<br />
determine whether the area is still periodically inundated or has saturated soils for sufficient<br />
duration to support the documented vegetation (a or b above). When a or b applies and there is<br />
no evidence of recent hydrologic alteration, or when a or b do not applv and there is<br />
documented evidence that the area is periodically inundated or has saturated soils, wetland<br />
hydrology is present. Otherwise, wetland hydrology does not occur on the area. Complete the<br />
hydrology section of DATA FORM 1 and PROCEED TO STEP 4.<br />
• STEP 4 - Determine Whether the Soils Parameter Must Be Considered. When either a or b<br />
of STEP 3 applies and there is either no evidence of recent hydrologic alteration of the project<br />
area or if wetland hydrology presently occurs on the area, hydric soils can be assumed to be<br />
present. If so, PROCEED TO STEP 6. Otherwise PROCEED TO STEP 5. o STEP 5 -<br />
Determine Whether Hydric Soils Are Present. Examine the soils data (Section B, STEP 7) and<br />
record the soil series or soil phase on DATA FORM 1 for each community type. Determine<br />
whether the soil is listed as a hydric soil (Appendix D, Section 2). If all community types have<br />
hydric soils, the entire project area has hydric soils. (CAUTION: If the soil series description<br />
makes reference to inclusions of other soil types, data must be field verified). Any portion of<br />
the area that lacks hydric soils is a nonwetland. Complete the soils section of each DATA<br />
FORM 1 and PROCEED TO STEP 6.<br />
• STEP 6 - <strong>Wetland</strong> Determination. Examine the DATA FORM 1 for each community type.<br />
Any portion of the project area is a wetland that has:<br />
a. Hydrophytic vegetation that conforms to one of the conditions identified in STEP 3a or 3b<br />
and has either no evidence of altered hydrology or confirmed wetland hydrology.<br />
25 February 1997 Environmental Techncal Services Co. 834 Castle Ridge Rd Austin, Texas 78746