I recently received a copy of a report prepared by NatureServe. The study is entitled "Biodiversity Values of Geographically Isolated Wetlands: An Analysis of 20 State". The paper is short with lots of numbers and percentages. The paper tries to highlight concerns for wetland systems that would be considered isolated in response to the SWANCC decision. Some might think that this paper demonstrates a potential mass extinction of species and habitats. I have a problem with the data. They examined data on wetland systems they considered isolated, but it does not appear that any of this data was gathered from decisions by the Corps of Engineers or even wetland experts with experience in mapping wetlands for Section 404 purposes. In addition, the paper adds to the confusion by introducing new terms, "partially isolated and strictly isolated". I will admit that I am not an expert and only have 25 years of experience in wetland mapping. However, I don't know that I have ever encountered a partially isolated wetland in the Section 404 program. I would like to know if anyone has read this paper and what your thoughts are.

[URL=www.natureserve.org/publications/isolated wetlands.jsp]Biodiversity Values of Geographically Isolated Wetlands[/URL]

Does the "partially isolated" key off groundwater vs. surface water connection?

That is a possibility. Unfortunately, the authors did not define the concept. With all the current debate over the term "isolated", I would like to know exactly how they utilized the term.

This article addressess the ditch issue and may help us understand partially isolated wetlands.


Definition of 'Ditch' Is Muddy at Best

Washington Post

By Cindy Skrzycki

Tuesday, March 29, 2005;

Everyone is digging his own ditch in this debate.

Under the 1972 Clean Water Act, the Environmental Protection Agency and the U.S. Army Corps of Engineers have jurisdiction over whether a ditch qualifies to be protected as a wetland.

The Corps considers whether a ditch is an isolated, non-navigable waterway open to development or a navigable U.S. waterway that deserves protection. This can include consideration of whether a ditch is a tributary, as some courts have ruled, and, thus, part of a U.S. waterway.

Seem a little confusing?

The distinctions and interpretations are left up to the Corps, which issues permits to protect wetlands from pollutants. The extent of its power has been controversial since the Supreme Court in 2001 struck down a "migratory bird rule" that gave regulators expansive authority to protect any kind of wetland used by a bird. The court said isolated, intrastate, non-navigable waters that have no connection to other waters could not be considered protected wetland in that circumstance.

At stake is the fate of thousands of miles of such isolated wetland, including the kinds of ditches that run along highways or drain farmland. Home builders and other business groups don't want ditches given more than their due, while environmentalists see ditches as an intricate part of the nation's hydrologic system that must be protected.

So the groups have been pressing regulators at EPA and the Corps of Engineers to clarify the policy and bring consistency to how these determinations are made in the field. They are also lobbying Congress to end the confusion over what constitutes an "isolated wetland."

"There is just pandemonium out there, but that is by design," said Julie Sibbing, senior program manager for wetlands policy for the National Wildlife Federation. "No one knows what is protected and what isn't."

The chief of the regulatory program for the Corps of Engineers agreed that things aren't too clear. "There is a lot of confusion about ditches right now," said Mark Sudol. "There is no guidance that says treat ditches one way or another."

Sibbing said the Corps has made "thousands and thousands of non-jurisdictional decisions" in the past few years, which means that the property in question is not covered by the protections of the Clean Water Act. Many of these designations involve bodies of water far larger than ditches.

But the National Association of Home Builders says Corps decisions are too expansive, resulting in builders having to "mitigate" the loss of wetlands before they can get a permit to go ahead with a project.

"We're talking about smaller, isolated areas. If the federal government had its way, everything would be regulated. This isn't the Chesapeake Bay or the Everglades or marshy areas along Puget Sound," said Duane Desiderio, staff vice president of legal affairs for the NAHB.


go here for the rest of the story:

http://www.washingtonpost.com/wp-dyn/articles/A8362-2005Mar28.html

I did not have a problem with the definition of partial isolation or strict isolation (see page 7 of the doscument). I found the authors treatment of that distinction quite clear. Also on page 7 the authors defined isolated for their study, which was different from the jurisdictional isolated wetland relevant to under Section 404.

I found the utility of the paper lessened because this and the focus on wetland systems rather than wetlands themselves. Isolated wetland systems were those where >80% of the occurrences of that system would meet the definition of isolated. Thus almost one-fith of the wetlands classified in their isolated wetland systems were not isolated.