Drawing wetland boundaries is half of the delineation process. The proposed revisions were based on at least three fundamental misconceptions. The misconception that the 1989 wetlands manual significantly expanded federal wetlands jurisdiction. Members of the administration have repeatedly claimed that the 1989 manual greatly expanded federal jurisdiction over wetlands to include many uplands. This belief evolved because, shortly after release of the manual, some federal field staff erroneously indicated that under the 1989 manual, any area with wetland soils was a wetland.
Many farmers use former wetlands that, though now drained, continue to have wetland soils.
The 1989 manual never in fact classified these areas as wetlands. The U. S. Army Corps of Engineers cleared up this misunderstanding through a guidance letter to its field staff in 1990. The recent round of federal field testing of the proposed new manual confirms that the 1989 manual did not significantly expand the reach of wetlands jurisdiction. Field test comparisons between the 1989 manual and the previously dominant 1987 manual of the Corps of Engineers revealed that of 169 sites delineated, the 1989 manual only identified seven more areas as wetlands- virtually all in Oregon. The 1989 manual did make some changes to the vegetation requirements because the 1987 manual had excluded certain wetland plants common in western states.