Wetland Delineations During Drought Conditions

On Wednesday, February 5, 2014 the US Army Corps of Engineers (COE) posted a Public Notice on conducting wetland delineations during drought conditions to their website. Due to the drought conditions that have developed over the past few years in California, the COE is recommending, when applicable, that delineators use the difficult Wetland Situations protocol. In the guidance posted, the COE identify two documents which describe approaches that may be useful in completing wetland delineations during periods of below-normal rainfall, drought conditions and unusually low winter snowpack. The documents identified include two Regional Supplements to the Corps of Engineers Wetland Delineation Manual, one for the Arid West Region and one for the Western Mountains, Valleys, and Coast Region.

Application of the procedures in these sections of the supplements should facilitate better decisions about vegetation and hydrology. DroughtUSIn some cases there may be a need to defer field work and/or a wetland determination, but there is no guarantee conditions will be closer to normal the next wet season. In general, wetland determinations on difficult or problematic sites must be based on the best information available to the field inspector, interpreted in light of his or her professional experience and knowledge of the ecology of wetlands in the region.

Based on the collective experience at Gallaway Enterprises applicants can expect to incorporate more remote sensed data and historical aerial photo interpretation into delineations. Applicants should also expect longer review times at the COE. We also caution applicants who receive a preliminary (PJD) jurisdictional determination from the COE during drought conditions. A PJD is almost worthless during drought conditions and serves no use as a project planning tool.

To view the Public Notice and links to the two documents go HERE