1987 Wetland Delineation Manual - The Wetlands Regulation Center

Wetland Delination Manual, 1987 67
f. Public or local government officials. Contact individuals who might have knowledge that
the area was periodically inundated.
If sufficient data on hydrology that existed prior to site alteration can be obtained to determine
whether wetland hydrology was previously present, PROCEED TO STEP 4. If not, a
determination involving hydrology cannot be made. Use other parameters (Subsections 1 and
2) for the wetland determination. Return to either the appropriate subsection of Section D or to
Section E and complete the necessary data forms. PROCEED TO STEP 4 if the previous
hydrology can be characterized. *
• STEP 4 - Determine Whether Wetland Hydrology Previously Occurred. Examine the
available data and determine whether indicators of wetland hydrology (PART III, paragraph
49) were present prior to site alteration. If no indicators of wetland hydrology were found, the
original hydrology of the area was not wetland hydrology. If indicators of wetland hydrology
were found, record the appropriate indicators on DATA FORM 3 and return either to the
appropriate subsection of Section D or to Section E and complete the wetland determination.
Subsection 4 - Man-Induced Wetlands
76. A man-induced wetland is an area that has developed at least some characteristics of
naturally occurring wetlands due to either intentional or incidental human activities. Examples
of man-induced wetlands include irrigated wetlands, wetlands resulting from impoundment
(e.g. reservoir shorelines), wetlands resulting from filling of formerly deepwater habitats,
dredged material disposal areas, and wetlands resulting from stream channel realignment.
Some man-induced wetlands may be subject to Section 404. In virtually all cases, maninduced
wetlands involve a significant change in the hydrologic regime, which may either
increase or decrease the wetness of the area. Although wetland indicators of all three
parameters (i.e. vegetation, soils, and hydrology) may be found in some man-induced
wetlands, indicators of hydric soils are usually absent. Hydric soils require long periods
(hundreds of years) for development of wetness characteristics, and most man-induced
wetlands have not been in existence for a sufficient period to allow development of hydric soil
characteristics. Therefore, application of the multiparameter approach in making wetland
determinations in man-induced wetlands must be based on the presence of hydrophytic
vegetation and wetland hydrology. (Uplands that support hydrophytic vegetation due to
agricultural irrigation and that have an obvious hydrologic connection to other “waters of the
United States” should not be delineated as wetlands under this subsection). There must also
be documented evidence that the wetland resulted from human activities. Employ the
following steps to determine whether an area consists of wetlands resulting from human
activities:
• STEP I - Determine Whether the Area Represents a Potential Man-Induced Wetland.
Consider the following questions:
25 February 1997 Environmental Techncal Services Co. 834 Castle Ridge Rd Austin, Texas 78746