1987 Wetland Delineation Manual - The Wetlands Regulation Center

Wetland Delination Manual, 1987 61
been employed, RETURN TO Section D or E to make a wetland determination. PROCEED
TO the appropriate subsection.
Subsection 1 - Vegetation
73. Employ the following steps to determine whether hydrophytic vegetation previously
occurred:
• STEP 1 - Describe the Type of Alteration. Examine the area and describe the type of
alteration that occurred. Look for evidence of selective harvesting, clear cutting, bulldozing,
recent conversion to agriculture, or other activities (e.g., burning, discing, or presence of
buildings, dams, levees, roads, parking lots, etc.). Determine the approximate date* when the
alteration occurred. Record observations on DATA FORM 3, and PROCEED TO STEP 2.
• STEP 2 - Describe Effects on Vegetation. Record on DATA FORM 3 a general description
of how the activities (STEP 1) have affected the plant communities. Consider the following:
a. Has all or a portion of the area been cleared of vegetation?
b. Has only one layer of the plant community (e.g. trees) been removed?
c. Has selective harvesting resulted in removal of some species?
d. Has all vegetation been covered by fill, dredged material, or structures?
e. Have increased water levels resulted in the death of some individuals?
It is especially important to determine whether the alteration occurred prior to implementation
of Section 404. PROCEED TO STEP 3.
• STEP 3 - Determine the Type of Vegetation That Previously Occurred. Obtain all possible
evidence of the type of plant communities that occurred in the area prior to alteration.
Potential sources of such evidence include:
a. Aerial photography. Recent (within 5 years) aerial photography
an often be used to document the type of previous vegetation. The general type of plant
communities formerly present can usually be determined, and species identification is
sometimes possible.
b. Onsite inspection. Many types of activities result in only partial removal of the previous
plant communities, and remaining species may be indicative of hydrophytic vegetation. In
other cases, plant fragments (e.g. stumps, roots) may be used to reconstruct the plant
community types that occurred prior to site alteration. Sometimes, this can be determined by
examining piles of debris resulting from land-clearing operations or excavation to uncover
identifiable remains of the previous plant community.
c. Previous site inspections. Documented evidence from previous inspections of the area may
describe the previous plant communities, particularly in cases where the area was altered after
a permit application was denied.
25 February 1997 Environmental Techncal Services Co. 834 Castle Ridge Rd Austin, Texas 78746