As a wetland consultant in my spare time, I basically agree with "anhinga" regarding the value of wetland inventories, the usefulness of the various maps, and detriments to relying to any great extent on an inventory for regulatory determinations.
I checked with the DEQ before the public hearings on these inventories, and they confirmed that they were produced largely to fulfill the apparent statutory requirement in Part 303. The maps are not intended as a final jurisdictional determination or even identification of wetland/upland. They are more like a general notice to landowners that have wetland mapped on their property, that they very likely will have a wetland "issue" sometime in the future if they choose to make use of their land.
One very positive aspect to these maps, as it was explained to me by DEQ, is that they allow the DEQ to take jurisdiction over wetlands that are not contiguous, but greater than 5 acres in counties with less than 100,000 population.
Why this last round of particular wetland maps just happened to be completed during the waning hours of the Engler administration, and what advantage there might be to that, I don't know. My understanding is that the latest inventories covered only about 7-8 counties, and prior to these, only a few counties have been completed. So, most of the State remains to be inventoried, or the maps completed. Based on my phone calls over the last few years inquiring about digital soil data for particular counties, my understanding is that much of it is not yet completed by USDA, and those counties that have been completed apparently include the counties for which wetland inventories were just issued. Essentially, these inventories have existed for roughly 15 years, but as 3 separate maps, NWI, MIRIS, and soil surveys. The soil surveys are the oldest, generally, but least specific to wetlands, but are very good indicators of what conditions may be present. Given all the budget cuts on both federal and state levels that have eliminated important environmental programs, I guess it's not hard to see how it took so long to put these 3 maps together. Anyone who has tried just to get a hard copy of a county soil survey has probably encountered the pathetic underfunding of this important reference.
Eventually, I think a more accurate inventory of wetlands and other significant natural features can and should be produced, but used as a permanent protection effort rather than just a regulatory program. The current inventories can at least be used to designate critical wetlands for protection through acquisition and other means.
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